16 research outputs found
The effect of polyunsaturated fatty acids on bovine sperm, in vitro
Artificial Insemination (AI) is the single most important tool in facilitating the genetic improvement of dairy cows. Both frozen and liquid semen are used in AI, however the majority (~95%) of insemination doses worldwide (and in Ireland) employ use of frozen semen (Vishwanath & Shannon, 2000). Only 5% of insemination doses used in Ireland are liquid semen, however, during peak breeding season of April and May, this number could rise to 25%. Use of frozen semen in AI has the benefit of long term storage as it causes the biochemical and developmental changes in sperm to stop, however, after the freeze thaw process, more than 50% of sperm cells are damaged (Vishwanath & Shannon, 2000), meaning a higher concentration of sperm cells per dose is required and therefore, less insemination doses per ejaculate are achieved. The use of stored fresh semen would remove this problem of damaged sperm cells after a freeze thaw process. Liquid semen would also allow a lower concentration of sperm cells per insemination dose, thereby, maximising the use of semen from high genetic merit bulls. It has been reported that although liquid bull semen maintains motility for up to 4 weeks post collection, in vivo fertility declines significantly after 4-5 days post collection (Vishwanath & Shannon, 1997). The reason for this sudden drop in fertility remains to be elucidated; however, it could be attributed to a number of factors, such as changes in the lipid profile and a subsequent loss in cell membrane fluidity, perhaps due to attack from reactive oxygen species (ROS). The addition of long chain fatty acids to bull sperm in vitro may have a stabilising effect on the sperm membrane, through fatty acids constituents being incorporated into the sperm cell membrane, as reported in a study by Neill & Masters (1971) or by inhibiting or reducing the lipid peroxidation (LPO) of the sperm membrane, which is high in polyunsaturated fatty acids
Anti-RSV prophylaxis efficacy for infants and young children with cystic fibrosis in Ireland
Rationale: There is limited evidence supporting the routine use of palivizumab in paediatric cystic fibrosis (CF)
patients to reduce respiratory syncytial virus (RSV) infection and related hospitalisation. Despite this, anti-RSV
prophylaxis is increasingly common. This is the first report from Ireland regarding palivizumab outcomes for
children with CF, under 2 years old, despite the greatest prevalence of CF globally.
Methods: An audit was performed at a tertiary hospital in Irelandâs mid-West to document all children with
CF, <24 months old, who received palivizumab over a five year period and comparision made with all eligible children
for the prior five year period who had not received the product (also CF patients). Palivizumab was administered to
both cohorts in their first year of life. Hospitalisation rates were compared using Fisherâs exact test. Incidence of RSV
and Pseudomonas aeruginosa infection was recorded.
Results: A total of 19 patients who received palivizumab were included in the study; comparision was made with a
retrospective control group of 30 patients. Prophylactic palivizumab did not prevent hospitalisation for 10/19 patients, 3
of whom were affected by RSV. This was significantly greater than in the control group, where no hospitalisations were
recorded (p < 0.0001). P. aeruginosa was isolated in one case from the study cohort, while no P. aeruginosa was detected
in the control group.
Conclusions: This study, the first of its kind from Ireland where CF prevalence is highest, does not provide unequivocal
support for prophylactic use of palivizumab in CF patients under 2 years. Despite being derived from a small sample size,
based on these data and complementary clinical observation, we have discontinued such prophylaxis. However, should
reported incidence of RSV-related hospitalisation increase, there is scientific plausibility for appropriately powered,
randomised, controlled trials of palivizumab
A case of failed eradication of cystic fibrosis-related sinus colonisation by Pseudomonas aeruginosa
Background: Pseudomonas aeruginosa is a pathogen associated with cystic fibrosis that has potential to decrease
lung function and cause respiratory failure. Paranasal sinuses are increasingly recognised as potential reservoirs for
intermittent colonisation by P. aeruginosa. This case documents investigation and outcome of P. aeruginosa
recurrence in a male paediatric patient over an eight year period.
Case presentation: A 12 year old Irish male paediatric cystic fibrosis patient experienced intermittent culturing of
P. aeruginosa from the oropharyngeal region, indicating chronic infection of the sinuses despite absence of symptoms,
retaining good lung function, and normal bronchoscopy and bronchoalveloar lavage. However, P. aeruginosa was isolated
from a sinus wash-out and was identified as a unique strain of P. aeruginosa that was also cultured from cough swabs.
Despite treatment, successful eradication from the paranasal sinuses was not achieved.
Conclusions: Few reports have addressed the paranasal sinuses as a reservoir for lung infection in cystic fibrosis patients
despite increased recognition of the need to investigate this niche. In this case, attempts at eradication of P. aeruginosa
present in paranasal sinuses including oral and nebulised antimicrobials proved unsuccessful. However, detection of
P. aeruginosa in the paranasal sinuses instigated antimicrobial treatment which may have contributed to prevention of
migration to the lower airways. Our outcome provides additional insight and may indicate utility of nasal lavage or nasal
endoscopy in paediatric cystic fibrosis patientsâ annual review clinic visits
Colonisation with extended-spectrum beta-lactamase (ESBL) not detected in a prevalence study.
Background
The Mid-West of Ireland has higher than average national rates of invasive extended-spectrum beta-lactamase (ESBL) bloodstream infections and carbapenemase-producing Enterobacteriaceae (CPE), with increasing numbers of ESBL isolates detected in community-dwelling patients.
Aims
To conduct a point prevalence study in a convenience sample of the Mid-West population with the aim of determining the extent of ESBL colonisation
Methods
Utilising anonymised community stool samples that had completed routine analysis, we conducted a point prevalence study over a four-week period on all samples that met defined inclusion and exclusion criteria. Limited epidemiological data was recorded: (1) age of patient, (2) gender, (3) sender location. From these stool specimens, rectal swabs were inoculated (eSwabâą 480CE, Copan, Italy), which were subsequently cultured on selective chromogenic agar (Colorexâą ESBL). Culture plates were incubated aerobically at 37ËC for 24 hours.
Results
Of 195 samples processed, 58% (n=112) were from females. The median patient age was 62.4 years (range 20-94 years). 186 samples (95%) originated from general practitioner clinics. During the study period, only nine eligible stool samples were received from LTCF (6 public). From 195 Colorexâą ESBL chromogenic agar plates cultured, no ESBL-producing organisms were detected.
Conclusions
This community point prevalence study did not identify ESBL-colonisation despite high numbers of patients with invasive ESBL bloodstream infections presenting for admission in our institution. We believe this may be because of our small sample size. Data regarding antimicrobial exposure and other risk factors for ESBL-colonisation was also not available. We remain vigilant for ESBL-producing organisms
An optimised work-flow to reduce time-to-detection of carbapenemase-producing Enterobacteriaceae (CPE) using direct testing from rectal swabs
Rapid detection of patients with carbapenem-producing Enterobacteriaceae (CPE) is essential for the prevention of nosocomial cross-transmission, allocation of isolation facilities and to protect patient safety. Here, we aimed to design a new laboratory work-flow, utilising existing laboratory resources, in order to reduce time-to-diagnosis of CPE. A review of the current CPE testing processes and of the literature was performed to identify a real-time commercial polymerase chain reaction (PCR) assay that could facilitate batch testing of CPE clinical specimens, with adequate CPE gene coverage. Stool specimens (210) were collected; CPE-positive inpatients (n=10) and anonymised community stool specimens (n=200). Rectal swabs (eSwabâą) were inoculated from collected stool specimens and a manual DNA extraction method (QIAampÂź DNA Stool Mini Kit) was employed. Extracted DNA was then processed on the Check-Direct CPEÂź assay. The three step process of making the eSwabâą, extracting DNA manually and running the Check-Direct CPEÂź assay, took <5 minutes, 1 hour 30 minutes and 1 hour 50 minutes, respectively. It was time efficient with a result available in under 4 hours, comparing favourably with the existing method of CPE screening; average time-to-diagnosis of 48/72 hours. Utilising this CPE work-flow would allow a âsame-dayâ result. Antimicrobial susceptibility testing results, as is current practice, would remain a ânext-dayâ result. In conclusion, the Check-Direct CPEÂź assay was easily integrated into a local laboratory work-flow and could facilitate a large volume of CPE screening specimens in a single batch, making it cost-effective and convenient for daily CPE testing
Systemic molecular mediators of inflammation differentiate Between crohnâs disease and ulcerative colitis, implicating threshold levels of IL-10 and relative ratios of pro-inflammatory cytokines in therapy
Background and Aims: Faecal diversion is associated with improvements in Crohnâs disease but not ulcerative colitis, indicating that differing mechanisms mediate the diseases. This study aimed to investigate levels of systemic mediators of inflammation, including fibrocytes and cytokines, [1] in patients with Crohnâs disease and ulcerative colitis preoperatively compared with healthy controls and [2] in patients with Crohnâs disease and ulcerative colitis prior to and following faecal diversion. Methods: Blood samples were obtained from healthy individuals and patients with Crohnâs
disease or ulcerative colitis. Levels of circulating fibrocytes were quantified using flow cytometric analysis and their potential relationship to risk factors of inflammatory bowel disease were determined. Levels of circulating cytokines involved in inflammation and fibrocyte recruitment and differentiation were investigated. Results: Circulating fibrocytes were elevated in Crohnâs disease and ulcerative colitis patients when compared with healthy controls. Smoking, or a history of smoking, was associated with increases in circulating fibrocytes in Crohnâs disease, but not ulcerative colitis. Cytokines involved in fibrocyte recruitment were increased in Crohnâs disease patients, whereas patients with ulcerative colitis displayed increased levels of pro-inflammatory cytokines. Faecal diversion in Crohnâs disease patients resulted in decreased circulating fibrocytes, pro-inflammatory cytokines, and TGF-ÎČ1, and increased IL-10, whereas the inverse was observed in ulcerative colitis patients. Conclusions: The clinical effect of faecal diversion in Crohnâs disease and ulcerative colitis may be explained by differing circulating fibrocyte and cytokine responses. Such differences aid in understanding the disease mechanisms and suggest a new therapeutic strategy for inflammatory bowel disease
The human mesenteric lymph node microbiome differentiates between Crohnâs disease and ulcerative colitis
Background and Aims:
Mesenteric lymph nodes are sites in which translocated bacteria incite and
progress immunological responses. For this reason, understanding the microbiome of mesenteric
lymph nodes in inflammatory bowel disease is important. The bacterial profile of Crohnâs disease
mesenteric lymph nodes has been analysed using culture-independent methods in only one
previous study. This study aimed to investigate the mesenteric lymph node microbiota from both
Crohnâs disease and ulcerative colitis patients.
Methods: Mesenteric lymph nodes were collected from Crohnâs disease and ulcerative colitis
patients undergoing resection. Total DNA was extracted from mesenteric lymph nodes and
assessed for the presence of bacterial DNA [16S]. All work was completed in a sterile environment
using aseptic techniques. Samples positive for 16S DNA underwent next-generation sequencing,
and the identity of bacterial phyla and species were determined.
Results: Crohnâs disease mesenteric lymph nodes had a distinctly different microbial profile to
that observed in ulcerative colitis. The relative abundance of Firmicutes was greater in nodes from
ulcerative colitis patients, whereas Proteobacteria were more abundant in Crohnâs disease. Although
species diversity was reduced in the mesenteric lymph nodes of patients with Crohnâs disease,
these lymph nodes contained greater numbers of less dominant phyla, mainly Fusobacteria.
Conclusion: This study confirms that there are distinct differences between the Crohnâs disease
and ulcerative colitis mesenteric lymph node microbiomes. Such microbial differences could aid in
the diagnosis of Crohnâs disease or ulcerative colitis, particularly in cases of indeterminate colitis at
time of resection, or help explain their mechanisms of development and progression
Assessment of the microbial load of airway clearance devices used by a cohort of children with cystic fibrosis
Background: Positive expiratory pressure (PEP) devices are an important element of the
management of cystic fibrosis, and of other respiratory diseases. Whereas there have been
reports in the literature of contamination of airway clearance devices and their surfaces
by microbial pathogens, there is little evidence available regarding such contamination
and its contribution to respiratory infection.
Aim: To establish whether pathogenic bacteria can contaminate PEP devices in the con text of normal cleaning and maintenance practices.
Methods: Patientsâ home-use clearance devices were brought to a routine clinic
appointment and collected for microbiology sampling and analysis. The patients were
provided with replacement devices. Nineteen such devices were collected from 17
patients, reflecting use of multiple devices by some patients. Swabs were taken and
cultured from each patientâs used device, the patientâs airway, as well as from new
unopened and unused devices that acted as controls.
Results: Seven of 19 devices (37%) tested positive for presence of pathogenic bacteria.
Device-cleaning methods varied among patients and non-sterilization methods were found
to be ineffective at removing pathogens. Microbial species found on the devices did not
correlate with those identified from airway swabs.
Conclusion: This study demonstrates the presence of pathogens on positive expiratory
pressure devices. The potential for transmission of these pathogens to the patientâs airway
and the risk of infection remains unclear and requires further study
Adults with Crohnâs disease exhibit elevated gynoid fat and reduced android fat irrespective of disease relapse or remission
Crohnâs disease (CD) is a debilitating inflammatory bowel condition of unknown aetiology that is growing in prevalence globally. Large-scale studies have determined associations between female obesity or low body mass index (BMI) with risk of CD at all ages or 8â< 40 years, respectively. For males, low BMI entering adult life is associated with increased incidence of CD or ulcerative colitis up to 40 years later. Body composition analysis has shown that combinations of lean tissue loss and high visceral fat predict poor CD outcomes. Here, we assessed dietary intake, physical activity and whole or regional body composition of patients with CD relapse or remission. This anthropometric approach
found people with CD, irrespective of relapse or remission, differed from a large representative healthy population sample in exhibiting elevated gynoid fat and reduced android fat. CD is associated with mesenteric adipose tissue, or âcreeping fatâ, that envelops affected intestine exclusive of other tissue; that fat is localised to the android region of the body. In this context, CD mesenteric adiposity represents a stark juxtaposition of organ-specific and regional adiposity. Although our study population was relatively small, we suggest tentatively that there is a rationale to refer to Crohnâs
disease as a fatty intestine condition, akin to fatty liver conditions. We suggest that our data provide early insight into a subject that potentially warrants further investigation across a larger patient cohor
Role of circulating ïŹbrocytes in the diagnosis of acute appendicitis
Background: Improved diagnostic biomarkers are required for acute appendicitis. The
circulating fibrocyte percentage (CFP) is increased in inflammatory states, but has not
been studied in acute appendicitis. This study aimed to determine CFP in acute appendicitis and compare diagnostic accuracy with standard serological biomarkers. Methods: A prospective cohort study was carried out between June2015 and February2016 at University Hospital Limerick. The CFP was determined by dual-staining peripheral venous samples for CD45 and collagen I using fluorescence-activated cell sorting, and correlated with histopathological diagnoses. The accuracy of CFP in determining histological acute appendicitis was characterized and compared with the white cell count, C-reactive protein concentration, neutrophil count, lymphocyte count and neutrophil:lymphocyte ratio. Results: Of 95 adults recruited, 15 were healthy individuals and 80 had suspected appendicitis at presentation. Forty-six of these 80 patients had an appendicectomy, of whom 34 had histologically confirmed appendicitis. The CFP was statistically higher in patients with pathologically proven acute appendicitis than in healthy controls(median6â
1 (i.q.r.1â
6â11â
6)versus2â
3(0 â
9â3â
4)percent respectively; P = 0â
008). The diagnostic accuracy of CFP, as determined using the area under the receiver operating characteristic(ROC)curve, was similar to that of standard biomarkers. In multinomial regression analysis, only raised CFP was retained as an independent prognostic determinant of acute appendicitis (odds ratio 1â
57, 95 per cent c.i. 1â
05 to 2â
33; P = 0â
027). Conclusion: The CFP is increased in histologically confirmed acute appendicitis and is as accurate as standard serological biomarkers in terms of diagnosi