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Biomedical subjects

D J Farrell

Publications and source records attributed to D J Farrell.

At least 19 recordsLinked to original sources
PubMed1999

Evaluation of AMPLICOR Neisseria gonorrhoeae PCR using cppB nested PCR and 16S rRNA PCR.

Certain strains of Neisseria subflava and Neisseria cinerea are known to produce false-positive results with the AMPLICOR Neisseria gonorrhoeae PCR (Roche Diagnostic Systems, Branchburg, N.J.). The analytical sensitivity and analytical specificity of three PCR tests were assessed with 3 geographically diverse N. gonorrhoeae strains and 30 non-N. gonorrhoeae Neisseria spp. The sensitivities of the in-house nested cppB gene and the 16S rRNA PCR methods were greater than that of the AMPLICOR N. gonorrhoeae PCR with purified DNA from all 3 N. gonorrhoeae strains. Six of 14 clinical strains of N. subflava (1 from a vaginal swab, 5 from respiratory sites) produced false-positive AMPLICOR N. gonorrhoeae PCR results and were negative by the two other PCR methods. When applied to 207 clinical specimens selected from a population with a high prevalence ( approximately 9%) of infection, the results for 15 of 96 (15.6%) AMPLICOR-positive specimens and 14 of 17 (82.3%) AMPLICOR-equivocal specimens were not confirmed by the more sensitive nested cppB PCR method. Only 2 of 94 (2.1%) of AMPLICOR N. gonorrhoeae PCR-negative specimens from the same population tested positive by the nested cppB method. These results suggest that for this population the AMPLICOR N. gonorrhoeae PCR test is suitable as a screening test only and all positive results should be confirmed by a PCR method that is more specific and at least as sensitive. This study also illustrates that caution should be used when introducing commercially available nucleic acid amplification-based diagnostic tests into the regimens of tests used for populations not previously tested with these products.

Bacterial Outer Membrane Proteins↗
PubMed1999

Nested duplex PCR to detect Bordetella pertussis and Bordetella parapertussis and its application in diagnosis of pertussis in nonmetropolitan Southeast Queensland, Australia.

A duplex PCR to detect Bordetella pertussis and Bordetella parapertussis was developed with the insertion sequences IS481 (B. pertussis) and IS1001 (B. parapertussis) and evaluated with specimens from 520 consecutive patients presenting with possible pertussis. No culture-positive-PCR-negative results occurred, giving the method a sensitivity of 100%. For B. pertussis, 58 of 520 patients (11.2%) were positive by PCR compared to 17 of 520 patients positive (3.3%) by culture. For B. parapertussis, 7 of 520 patients (1.3%) were positive by PCR compared to 2 of 520 patients positive (0.4%) by culture. Two patients were positive for both B. pertussis and B. parapertussis. Patient records were reviewed to determine the validity of PCR-positive-culture-negative results. Forty-two of 49 patients who could be evaluated fulfilled the criteria for a case definition of pertussis, with 32 patients being <1 year of age and having classical pertussis symptoms. The seven patients who did not fulfil the criteria were aged 7 to 55 years and had a persistent cough for >2 weeks. The method was also used to investigate a classroom outbreak in which B. pertussis culture was positive for 5 of 28 patients. All five culture-positive specimens were confirmed by PCR, and an additional eight were positive by PCR. Of 25 patients from a suspected pertussis outbreak in a girls' dormitory, seven of seven specimens were negative for B. pertussis, although 13 of 25 patients were positive for B. pertussis immunoglobulin M (IgM) (2 of which produced equivocal IgA results, with 23 of 25 patients being negative). Five symptomatic patients were subsequently found to be positive (by IgM and particle agglutination assays) for Mycoplasma pneumoniae, demonstrating the value of PCR in rapidly excluding B. pertussis infection in an outbreak situation. Twenty-two of 71 (30. 1%) throat swabs were positive by PCR compared to 2 of 71 (2.8%) throat swabs positive by culture, indicating that a reassessment of the use of throat swabs should be considered, particularly for older patients, in contact tracing, and in situations in which specimen collection is difficult.

Antibodies, Bacterial↗
PubMed1998

Strategies to improve the nutritive value of rice bran in poultry diets. III. The addition of inorganic phosphorus and a phytase to duck diets.

1. In the first of 2 experiments ducklings grown from 2 to 19 d were given diets with 0, 200 or 400 g rice bran, with or without a phytase and with 1 or 3 g inorganic phosphorus (Pi) per kg for rice bran-based diets only. In the 2nd experiment rice bran concentrations were 0, 300 or 600 g rice bran per kg with or without a phytase and 1 g Pi/kg. Ducks were grown from 19 to 40 d of age. 2. In experiment 1, a response to phytase was observed for weight gain and food intake on most diets except those with 200 g rice bran (3 g Pi) and 4.00 g rice bran (1 g P)i/kg. Main effects showed that 400 g rice bran depressed growth rate and food conversion ratio (FCR); increasing Pi depressed food intake, while food phytase increased food intake and growth rate over 2 to 19 d. There were several interactions. Dry matter and P retention were reduced but N digestibility improved when rice bran was increased from 200 g to 400 g/kg at 2 to 10 d of age; apparent metabolisable energy (AME) and calcium retentions were improved, similar results being seen at 10 to 19 d of age. Calcium and P retentions increased with the addition of food phytase and, at 10 to 19 d of age, phytase increased dry matter digestibility. Increasing Pi improved calcium and P retention, but only at 2 to 10 d of age. 3. Tibia ash (g or g/kg) content of bone was lowest on the diet without rice bran and without phytase; Pi concentration had no effect but phytase increased tibia ash on diets with 0 and 200 g rice bran and 1 g Pi/kg. Retention of several minerals in tibia ash declined at the highest rice bran inclusion rate; Pi level and phytase both increased Mg retention. 4. In experiment 2, food intake and growth rate of ducks, but not FCR, declined as rice bran inclusion increased from 0 to 600 g/kg. Phytase improved growth rate but not food intake and FCR on all 3 diets. Dry matter digestibility declined with increasing rice bran inclusion, but AME increased; retention of P and Mg declined but those of Ca and Fe increased. Phytase improved dry matter digestibility and retention of N and P. AME also increased but this was only on diets with 0 and 600 g rice bran/kg. There were reductions of 8% and 10% in P excreted in experiments 1 and 2 respectively when food phytase was added. 5. Tibia ash declined with increasing dietary inclusion of rice bran. Zn and Mn in ash tended to decline and Mg to increase; Ca and P showed no change in concentration in tibia ash. Again, phytase increased tibia ash content in bone. 6. It was concluded that there were a number of unexpected benefits from adding a food phytase to these diets, which resulted in improved nutrient yield and bird performance, although several of the diets appeared to be adequate in available P.

6-Phytase↗
PubMed1998

Strategies to improve the nutritive value of rice bran in poultry diets. IV. Effects of addition of fish meal and a microbial phytase to duckling diets on bird performance and amino acid digestibility.

1. Ducklings were given diets with vegetable protein (VP) and 0 or 600 g rice bran/kg; fish meal (60 g/kg) and a phytase (+, -) were added to the diets (VP + AP). An additional 40 g soyabean meal/kg was added to the diet with rice bran (VP ++). Amino acid digestibility and mineral retention were measured in the lower ileum of ducklings killed at 23 d of age. Acid insoluble ash was used as an inert marker. Trypsin and amylase activities were also measured and weights of the pancreas and small intestine recorded at slaughter. 2. Addition of soyabean meal (VP ++) to the diet with rice bran improved growth rate and food intake compared to the diet without (VP) and gave the same food intake and growth rate as the comparable basal diet (VP) without rice bran. Fish meal improved growth rate on the diets without rice bran and improved food intake on this diet (VP + AP). Rice bran depressed growth rate and food conversion ratio (FCR); protein source affected growth rate, food intake and FCR; phytase increased food intake only. There were several interactions. 3. Determined total amino acid composition of the diets appeared to meet the essential amino acid requirements of ducklings. Rice bran depressed the ileal digestibility of virtually all amino acids and phytase had no direct effect, although there were interactions. Fish meal addition to diets with rice bran improved the apparent digestibility of several essential amino acids as well as that of dry matter and crude protein. 4. Ileal retention of some minerals and tibia ash content were reduced by rice bran. Fish meal and phytase inclusion increased P retention and ash in tibia. 5. Higher intestinal trypsin activity and increased pancreas size were seen in ducklings on diets with rice bran compared to those without. Intestinal amylase activity was reduced in ducklings given rice bran, probably because of its low starch content. 6. The stimulating effect of fish meal on duckling performance was probably caused in part by the improvement in the digestibility of some amino acids. The addition of small amounts of minerals in fish meal may have increased mineral retention. Phytase gave benefits anticipated from our previous work, but also improved lysine and threonine digestibility in diets containing vegetable protein only.

6-Phytase↗
PubMed1998

Strategies to improve the nutritive value of rice bran in poultry diets. I. The addition of food enzymes to target the non-starch polysaccharide fractions in diets of chickens and ducks gave no response.

1. Three experiments were undertaken to test the efficacy of 2 enzymes targeting mainly the non-starch polysaccharides (NSPs) in rice bran. 2. In experiment one, 400 g rice bran/kg depressed chick performance and there was a significant decline in growth rate and food intake with increasing inclusion of rice bran (0, 200, 400 g). Neither enzyme had any benefit. 3. In experiment two, rice bran (inclusion 200 and 400 g/kg), did not alter growth rate, food intake or food conversion ratio of duckling (3 to 17 d of age). Again enzyme addition gave no response. 4. In experiment three, 300 g rice bran/kg stimulated duck (19 to 35 d of age) growth while 600 g rice bran/kg depressed growth but not food intake. Enzymes gave no response. 5. Relative gut viscosity declined with increasing rice bran inclusion as did dry matter in ileal digesta. There were differences between ducklings and chickens. 6. It was concluded that NSPs were not a significant factor in altering the nutritive value of rice bran and the enzymes used were therefore unlikely to be of benefit.

Animals↗
PubMed1998

Strategies to improve the nutritive value of rice bran in poultry diets. II. Changes in oil digestibility, metabolisable energy and attempts to increase the digestibility of the oil fraction in the diets of chickens and ducklings.

1. In experiment 1, the effects of age on oil digestibility and apparent metabolisable energy (AME) were measured in chickens and ducklings between 3 and 28 d of age on a diet with 400 g rice bran/kg. In experiment 2, a biosurfactant and a food lipase were added to diets of chickens containing 200 and 400 g rice bran/kg. In experiment 3, chicken diets containing 0 or 400 g rice bran/kg were supplemented with a food lipase (2 concentrations) or a food enzyme or their combination. 2. In experiment 1, oil metabolisability and AME increased substantially as chickens aged. Oil metabolisability was much higher in ducklings, when comparisons were made with chickens of similar age. 3. In experiment 2, lipase or biosurfactant gave no improvement in bird performance. Growth rate and food conversion ratio were, respectively, 23% and 10% better on diets with 200 compared to 400 g rice bran/kg. 4. In experiment 3, there was a significant growth response to lipase plus the enzyme mixture on the diet with 200 g rice bran/kg. On the diet with 400 g rice bran/kg, growth improvement was seen with the enzyme mixture only. 5. In experiment 3, enzyme addition did not increase oil metabolisability or AME. At 4 to 8 d of age AME was higher on the diet without rice bran but oil metabolisability was the same as on the diet with rice bran. At 19 to 23 d of age AME was similar but oil metabolisability was higher on the diet with rice bran than without. Droppings' dry matter was higher on diets without than with rice bran (32.4 vs 27.1%). 6. The response to lipase and the combination of this and a food enzyme suggest that there may be benefit in examining this interaction further although they had no effect on oil metabolisability or on AME. It is concluded that a stable AME for rice bran cannot be provided for chickens until at least 21 d of age.

Aging↗
PubMed1998

Enrichment of hen eggs with n-3 long-chain fatty acids and evaluation of enriched eggs in humans.

Eggs enriched with n-3 polyunsaturated fatty acids (PUFAs) were produced by hens fed diets containing fish oil or a combination of fish and vegetable oils. In a sensory evaluation, 78 untrained volunteers could not distinguish between ordinary and enriched eggs. Storage life was also not significantly different between egg types. A food intake survey of 4 groups of 14 subjects each who consumed 7 eggs/wk for 24 wk showed that intakes of the major dietary components were not significantly different for 4 different egg types. Mean (n = 56) plasma cholesterol and triacylglycerol concentrations were not significantly different at the start and finish of the study. Body weight and HDL concentrations increased during the study (P < 0.05). For the last 2 wk of the experiment (weeks 23-24), mean egg consumption was increased from a total of 14 to a total of 21 eggs, resulting in a small increase in plasma triacylglycerols only. There were no significant differences (P > 0.05) in body weight, blood pressure, or plasma lipid components among treatment groups consuming the 4 different egg types. Blood samples taken after 16 and 22 wk from fasted subjects showed significant increases in eicosapentaenoic acid, docosahexaenoic acid, and total n-3 PUFAs in subjects consuming enriched eggs compared with controls. In addition, the ratio of n-6 to n-3 PUFAs in plasma was significantly reduced from 12.2:1 to 6.5-7.7:1 in subjects consuming enriched eggs compared with controls. Consumption of only one enriched egg daily can contribute substantially to the recommended daily intake of n-3 PUFAs.

Adult↗
PubMed1997

Comparison of growth performance and nutrient retention of weaner pigs given diets based on casein, free amino acids or conventional proteins.

In two experiments the potential value of diets based on casein or free amino acids (FAA) for amino acid utilization experiments were examined. In Expt 1 the optimum dietary electrolyte balance (dEB) for a casein-based diet was estimated by supplemention with 10 or 20 g NaHCO3/kg, to produce diets containing 64, 183 or 302 mmol/kg. In addition, piglet growth performance and efficiency of nutrient deposition of piglets given the casein diets were compared with two multiple protein source diets; Supercreep, a commercial multiple protein source diet or CFS (casein-fish-soyabean-sugar) or a FAA-based diet. Expt 2 was designed to compare piglet response to FAA diet stored at -15 degrees with twice daily feeding, with FAA diet stored at ambient temperature (13-30 degrees) and offered ad libitum. A CFS diet was used as a positive control and the experiment was conducted over the 10-20 kg growth phase. Expt 1 used forty-eight piglets weaned at 20-22 d of age and allocated to one of six treatments formulated to contain at least 0.84 g lysine/MJ digestible energy in a randomized block design. Piglets given the CFS and Supercreep diets produced superior growth rates (518, 491 g/d) to those given a FAA diet (353 g/d) or casein diet containing 0, 10 or 20 g NaHCO3/kg respectively (365, 417, 390 g/d) between 5 and 20 kg live weight. Piglets given the casein and FAA diets had higher amino acid digestibilities than those given the Supercreep and CFS diets. The increase in the dEB of the casein diet from 64 to 183 mmol/kg improved piglet growth performance between 5 and 20 kg by 14%. All piglets given casein diets had similar ileal and faecal digestibilities, empty-body compositions, nutrient deposition rates and retention ratios. The results of Expt 2 showed that there was no beneficial effect on piglet performance of storing the FAA diet at -15 degrees and feeding twice daily. Based on the results of these two experiments, neither the casein (0, 10, 20 g NaHCO3/kg) nor FAA diets were suitable for estimating amino acid utilization by the piglet. There remain unidentified factors which limit the growth performance of piglets given the casein and FAA diets.

Amino Acids↗
PubMed1997

The reliability of Microscan conventional and rapid panels to identify Staphylococcus aureus and detect methicillin resistance: an evaluation using the tube coagulase test and mecA PCR.

Microscan (Dade Diagnostics, Brisbane) Positive Combo Type 6 (312 panels) and Rapid Positive Breakpoint Type 1 (62 panels) were evaluated for Staphylococcus aureus identification, using the tube coagulase test (TC), and oxacillin susceptibility, using mecA. A total of 374 consecutive clinical staphylococci were tested, with TC and Microscan having 100% correlation (335 identified as S. aureus and 39 as coagulase negative staphylococci by both methods). A 93% correlation was observed between Microscan and mecA PCR for oxacillin susceptibility. No very major errors (0/374 false oxacillin susceptibility) and 26 (7%) major errors (26/374 false oxacillin resistance) were found showing false resistance to oxacillin to be a problem in our population. Oxacillin Etest (AB Biodisk, Sweden) was performed on all oxacillin resistant isolates. A bimodal distribution was observed between mecA positive and negative isolates. A testing algorithm (using the Microscan panels and Etest) was developed for this laboratory to detect mecA encoded methicillin resistance. Retrospective application of this algorithm to the 374 isolates gave 100% correlation with mecA detection.

Bacteriological Techniques↗
PubMed1997

The role of Ureaplasma urealyticum in adverse pregnancy outcome.

We investigated Ureaplasma urealyticum genital tract colonization rates in an Australian population to determine whether colonization was associated with adverse pregnancy outcome. Women attending an antenatal clinic were evaluated for lower genital tract colonization at their first antenatal visit (162 women) and at 28 weeks' gestation (120 women). Placentas from 92 women were cultured. U. urealyticum was the predominant isolate from the lower (57.4%) and upper (17.4%) genital tract in this population of pregnant women. U. urealyticum was a persistent colonizer during mid-trimester of pregnancy (in 88% of women colonized) whereas M. hominis, G. vaginalis, and Group B streptococcus were present as transient flora of the lower genital tract. Lower genital tract colonization during pregnancy was not directly associated with adverse pregnancy outcome. However preterm delivery in afebrile, asymptomatic women, could possibly be associated with chorioamnionitis (4 of 16 preterm births). Screening of women with a history of preterm birth may prevent upper genital tract infections and preterm delivery.

Adult↗
PubMed1997

Do intensive care drug infusions support microbial growth?

The potential for commonly infused drug solutions to support or inhibit microbial growth was explored in this study. Drugs examined were midazolam HCl, morphine sulphate, fentanyl citrate, pethidine HCl, bupivacaine HCl, atracurium besylate, vecuronium bromide, adrenaline, dopamine, dobutamine, noradrenaline, isoprenaline, glyceryl trinitrate, sodium nitroprusside and propofol. All drugs were studied in both diluted and undiluted forms. Of the 15 medications investigated, all except propofol were found to be bactericidal and to reduce fungal growth.

Anesthetics, Intravenous↗
PubMed1996

Immunohistochemical expression of endothelial markers in left atrial myxomas: a study of six cases.

Vascular endothelial cells are antigenically heterogeneous and therefore it has been recommended that a range of immunohistochemical markers is employed to show the presence of cells of endothelial origin in surgical pathology. In this study we applied three monoclonal antibodies--to factor VIII-related antigen, JC70 (CD31), QBend 10 (CD34)--and Ulex europaeus agglutinin type 1 lectin (UEA-1), to six consecutive cases of left atrial myxoma. We found that JC70 and QBend 10 consistently stained myxoma cells in all their different growth patterns contrasting with factor VIII-related antigen expression and UEA-1 binding which were restricted to areas which showed morphological evidence of vascular differentiation. These findings suggest that the constituent cells of atrial myxomas show more widespread endothelial differentiation than has previously been recognized and that differences in immunohistochemical staining may reflect the maturation status of these cells.

Adult↗
PubMed1996

Comparison of PCR/nucleic acid hybridization and EIA for the detection of Chlamydia trachomatis in different populations in a regional centre.

Culture on McCoy cell monolayers has been accepted as the reference method for the detection of Chlamydia trachomatis. Recent studies have shown that polymerase chain reaction (PCR)/nucleic acid hybridization based methods have increased sensitivity over culture while still retaining specificity. In situations where organism viability is of concern, due to factors such as transportation delays, culture is inappropriate. Regional laboratories therefore have not been able to utilize the reference method and have been forced to use less reliable methods. The aims of our study were to assess the feasibility of performing PCR to diagnose infections due to C. trachomatis in a regional laboratory using a new commercial kit--Amplicor (Roche Molecular Systems, Branchburg, NJ) and to compare the current enzyme-immunoassay (EIA) based-methods used in our laboratory (VIDAS [bioMerieux Vitek, Hazelwood MO] and IDEIA [Novo Nordisk Diagnostics, Cambridge, UK]) against PCR. Thirteen positive Amplicor specimens were found in 267 urine specimens collected from asymptomatic adolescent males and females. All 13 were confirmed positive using major outer membrane protein gene PCR (MOMP). VIDAS and IDEIA showed 100% correlation to each other but only detected 5/13 positives. Of 140 consecutive patients attending the regional sexual health clinic, 13 were Amplicor positive, 11/13 MOMP positive and 10/13 positive by VIDAS. Five of 254 patients attending the hospital antenatal clinic were positive by Amplicor, all being confirmed by MOMP. No PCR inhibition was detected in a random sample of 100 varied negative Amplicor tests using a modification of the Amplicor kit. No contamination was experienced. The Amplicor kit was shown to be suitable for use in the routine clinical laboratory with minimal disruption to workflow. For regional laboratories this kit should provide more accurate results than EIA based methods, particularly in the detection of asymptomatic persons.

Adolescent↗
PubMed1996

Primary malignant melanoma of the bronchus.

A rare case of primary malignant melanoma of the bronchus is described. Before considering this diagnosis, metastasis from an occult primary must be convincingly excluded and the tumour should conform to certain guidelines. This patient presented with a solitary lung tumour for which she underwent left lower lobectomy and continues to be tumour free 54 months after surgery. Two possible mechanisms of aetiology are suggested.

Aged↗
PubMed1995

Intrahepatic mast cells in chronic liver diseases.

Mast cells are known to be present in human liver but their distribution and density in normal livers and in chronic liver diseases have not previously been examined. In this study, we quantified mast cell numbers and examined their distribution in percutaneous biopsy specimens from normal livers (n = 8) and in two chronic progressive liver diseases: primary biliary cirrhosis (PBC) (n = 40) and alcoholic liver disease (n = 33). We compared differences in mast cell density between these two forms of chronic liver disease because it had been suggested that mast cells may play a role in the development of liver fibrosis, particularly in patients with chronic cholestatic liver disease who frequently have increased plasma histamine levels. Mast cells were identified by immunohistochemistry using a specific monoclonal antibody (AA1) raised against mast cell tryptase after an initial study showed this to be more sensitive for the detection of mast cells than the conventional histochemical stain, toluidine blue. Our results showed that small numbers of mast cells (3.9 +/- 3.3/mm2) are present within the portal tracts and sinusoids of normal livers. In progressive chronic liver disease, increased numbers of mast cells were present, which correlated with the increasing amounts of liver fibrosis present. We found significantly more mast cells in the PBC group compared with the alcoholic group for a given amount of fibrosis. Our findings suggest that mast cells and their mediators may play a role in liver fibrogenesis.

Biopsy↗
PubMed1995

Multiple hepatic abscesses due to Yersinia enterocolitica.

We report a case of multiple hepatic abscesses due to Yersinia enterocolitica in a 58 yr old male. This case is typical of the other 39 cases reported in the literature in that the patient had alcoholism, malnutrition, iron overload and a subsequently diagnosed malignancy. Ultrasound showed multiple hypoechoic areas in the liver which were confirmed by CT scan. The patient also had a rectal lesion initially thought to be malignant, leading to a presumptive diagnosis of metastatic disease. A CT-guided fine needle aspiration biopsy of a liver lesion unexpectedly revealed pus which subsequently grew Yersinia enterocolitica. The organism was also isolated from the patient's blood and feces. This case illustrates the need for histological microbiological investigation of radiologically diagnosed presumptive malignancy.

Alcoholism↗
PubMed1995

Evidence against the involvement of Mycobacterium ulcerans in most cases of necrotic arachnidism.

Cutaneous lesions caused by M. ulcerans were shown to bear only a superficial resemblance to those produced by certain spider species. M. ulcerans was not found in either the venoms or the midguts of several Australian spiders, and deliberate contamination by inoculation of the fangs and digestive system of the wolf spider, Lycosa godeffroyi, did not result in permanent colonization. M. ulcerans was successfully introduced into the skin of mice through a small trauma site similar to that caused by a spider bite. However, because M. ulcerans was shown to survive on exposed surfaces for only a short period, a successful inoculation is likely only if the skin is contaminated with this organism after, or at the same time as, the skin suffers damage. The claim by other workers that M. ulcerans produces cutaneous ulcers by release of an exotoxin could not be confirmed. The authors conclude that M. ulcerans is not involved in most cases of necrotic arachnidism and hence there is no justification for prescribing anti-mycobacterial antibiotics to resolve alleged spider bite lesions unless the presence of M. ulcerans has been demonstrated by appropriate laboratory tests.

Administration, Cutaneous↗