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Biomedical subjects

A Pijpers

Publications and source records attributed to A Pijpers.

At least 19 recordsLinked to original sources
PubMed2005

Comparison of culture, PCR, and different serologic tests for detection of Mycoplasma gallisepticum and Mycoplasma synoviae infections.

In this study, the technical performance of culture, two commercially available polymerase chain reaction (PCR) tests, rapid plate agglutination (RPA) test, hemagglutination inhibition (HI) test, and eight commercially available enzyme-linked immunosorbent assays (ELISAs) were compared for the detection of avian mycoplasma infections from 3 days postinfection (d.p.i.) through 35 d.p.i. The tests were carried out on samples from specified pathogen-free layers that were infected at 66 wk of age with recent Mycoplasma synoviae (MS) and Mycoplasma gallisepticum (MG) field strains, MS and MG ATCC strains, and Mycoplasma imitans (MIM), respectively. Results showed a high percentage of positive samples in the homologous infected groups and a high percentage of negative samples (100%) in the uninfected and heterologous infected groups during 35 d.p.i. of both culture and PCR tests. For the group infected with the MG 15302 ATCC strain, serology was more sensitive than bacteriology. All MG and MS tests, with the exception of MG ELISA kit D showed a lower percentage of positive samples during 35 d.p.i. for the detection of the MG and MS ATCC strain infection compared with that of the field strains. Also, the number of cross-reactions (false positives) in the serologic tests was lower after infection with an ATCC strain than after an infection with the MG or MS field strain. Contradictory to other studies, the ELISAs and the RPA test using undiluted serum showed a relatively high number of false-positive results. The MG ELISAs (except ELISA kit D) showed more false-positive results (up to 37%) in the MIM-infected group than in the MS-infected groups. This was not unexpected, as MIM and MG have a close antigenic relationship. The results of the serologic tests in this study showed that a certain level of false-positive results can be expected in about any serologic test. Although the level of false-positive results varied between several serologic tests, this study showed that it is not advisable to rely completely on one test (system) only.

Agglutination Tests↗
PubMed2004

A serological survey for pathogens in old fancy chicken breeds in central and eastern part of The Netherlands.

To get an impression of the presence of pathogens in multi-aged flocks of old fancy chicken breeds in the Netherlands, plasma samples originating from 24 flocks were examined for antibodies against 17 chicken pathogens. These flocks were housed mainly in the centre and east of the Netherlands, regions with a high poultry density. The owners of the tested flocks showed their chicken at national and international poultry exhibitions. Antibodies against Avian Influenza, Egg Drop Syndrome '76 virus, Pox virus, Salmonella pullorum/gallinarum, Salmonella Enteritidis or Salmonella Typhimurium were not detected. However, antibodies against other Salmonella species, Mycoplasma gallisepticum, infectious bursal disease virus, infectious bronchitis virus, avian encephalomyelitis virus, chicken anaemia virus, infectious laryngotracheitis virus, and avian leukosis virus, subgroups A and B, and subgroup J were detected in a varying proportion of the flocks. This study shows that antibodies against many chicken pathogens are present among the flocks of old fancy chicken breeds that are exhibited at international poultry exhibitions.

Animals↗
PubMed2004

The highly pathogenic avian influenza A (H7N7) virus epidemic in The Netherlands in 2003--lessons learned from the first five outbreaks.

Clinical signs and gross lesions observed in poultry submitted for postmortem examination (PME) from the first five infected poultry flocks preceding the detection of the primary outbreak of highly pathogenic avian influenza (HPAI) of subtype H7N7 during the 2003 epidemic in the Netherlands are described. The absence of HPAI from the Netherlands for more than 75 yr created a situation in which poultry farmers and veterinary practitioners did not think of AI in the differential diagnosis as a possible cause of the clinical problems seen. Increased and progressive mortality was not reported to the governmental authorities by farmers or veterinary practitioners. It took 4 days from the first entry of postmortem material to notify the governmental authorities of a strong suspicion of an AI outbreak on the basis of a positive immunofluoresence test result. The gross lesions observed at PME did not comply with the descriptions in literature, especially the lack of hemorrhagic changes in tissues, and the lack of edema and cyanosis in comb and wattles is noted. The following lessons are learned from this epidemic: a) in the future, increased and progressive mortality should be a signal to exclude AI as cause of disease problems on poultry farms; b) intensive contact between the veterinary practitioner in the field and the veterinarian executing PME is necessary to have all relevant data and developments at one's disposal to come to a conclusive diagnosis; c) in an anamnesis, reporting of high or increased mortality should be quantified in the future (number of dead birds in relation to the number of birds brought to the farm to start production, together with the timing within the production cycle), or else this mortality cannot be interpreted properly; d) if clinical findings such as high mortality indicate the possibility of HPAI, the pathologist should submit clinical samples to the reference laboratory, even if PME gives no specific indications for HPAI; e) the best way to facilitate early detection of an HPAI outbreak is to have the poultry farmer and/or veterinary practitioner immediately report to the syndrome-reporting system currently in operation the occurrence of high mortality, a large decrease in feed or water intake, or a considerable drop in egg production; f) in order to detect low pathogenic avian influenza infections that could possibly change to HPAI, a continuous serologic monitoring system has been set up, in which commercial poultry flocks are screened for antibodies against AI virus of subtypes H5 and H7.

Animals↗
PubMed2002

Cellular immune response in the small intestine of two broiler chicken lines orally inoculated with malabsorption syndrome homogenates.

We studied the cellular immune response against malabsorption syndrome (MAS) in two broiler chicken lines, A and B. We determined the number of pan T-lymphocytes (CD3), helper T-lymphocytes (CD4), cytotoxic T-lymphocytes (CD8) and macrophages/monocytes in the small intestine in the first 2 weeks after oral inoculation of two MAS homogenates, MAS80 and MAS97-1. The immune cells were detected on cryostat tissue by immunohistochemistry and counted by villus area. In trial 1, we compared the two broiler lines for weight gain depression, intestinal lesion and number of CD3, CD4, CD8 cells and macrophages/monocytes after MAS80 inoculation. Although there was no significant difference in weight gain depression between the two broiler lines, line B had significantly higher numbers of CD8+ T-cells per villus area than had line A. To confirm part of the results of trial 1, trial 2 was done in which we compared different homogenates in broiler line B. Broiler line B was orally inoculated with either MAS97-1, intestinal homogenate obtained from healthy chickens (healthy homogenate), or phosphate buffered saline (PBS). In this trial, the MAS97-1 homogenate also induced weight gain depression and intestinal lesions, whereas the "healthy homogenate" and PBS did not induce weight gain depression or intestinal lesions. The broilers inoculated with MAS97-1 homogenate had significantly more CD8+ T-cells per villus area than had broilers inoculated with "healthy homogenate" or PBS. Increased CD8+ T-cells per villus area in the affected small intestines of broilers suggests an increase of cytotoxic T-cell activity.

Animals↗
PubMed2001

Pharmacokinetics of sulfadimethoxine and sulfamethoxazole in combination with trimethoprim after oral single- and multiple-dose administration to healthy pigs.

The pharmacokinetics were studied of sulfadimethoxine (SDM) or sulfamethoxazole (SMX) in combination with trimethoprim (TMP) administered as a single oral dose (25 mg + 5 mg per kg body weight) to two groups of 6 healthy pigs. The elimination half-lives of SMX and TMP were quite similar (2-3 h); SDM had a relatively long half-life of 13 h. Both sulfonamides (S) were exclusively metabolized to N4-acetyl derivatives but to different extents. The main metabolic pathway for TMP was O-demethylation and subsequent conjugation. In addition, the plasma concentrations of these drugs and their main metabolites after medication with different in-feed concentrations were determined. The drug (S:TMP) concentrations in the feed were 250:50, 500:100, and 1000:200 mg per kg. Steady-state concentrations were achieved within 48 h of feed medication, twice daily (SDM+TMP) or three times a day (SMX+TMP). Protein binding of SDM and its metabolite was high (>93%), whereas SMX, TMP and their metabolites showed moderate binding (48-75%). Feed medication with 500 ppm sulfonamide combined with 100 ppm TMP provided minimum steady-state plasma concentrations (C(ss,min)) higher than the concentration required for inhibition of the growth of 90% of Actinobacillus pleuropneumoniae strains (n = 20).

Administration, Oral↗
PubMed2000

Prevention of pleuropneumonia in pigs by in-feed medication with sulphadimethoxine and sulphamethoxazole in combination with trimethoprim.

The prophylactic effect of in-feed medication of conventional pigs with sulphadimethoxine (SDM), sulphamethoxazole (SMX), and trimethoprim (TMP) was tested by using an Actinobacillus pleuropneumoniae infection model. In each of five experiments, six pigs were given medicated feed twice daily and three pigs received antibiotic-free feed and served as positive (unmedicated, infected) controls. The following drugs or drug combinations were tested (in mg per kg feed): 500 SDM + 100 TMP, 500 SMX + 100 TMP, 125 SMX + 25 TMP, 125 SMX (alone) and 25 TMP (alone). After six days of feed medication, all animals were endobronchially inoculated with A. pleuropneumoniae in a dose of 1-3.10(4) colony-forming units (CFU). The response to the challenge in all control pigs was characterized by fever, lethargy, anorexia, reduced water consumption, and laboured breathing. At autopsy all controls manifested a fibrinous haemorrhagic pleuropneumonia. In-feed medication with 500 SDM + 100 TMP, 500 SMX + 100 TMP as well as 125 SMX + 25 TMP resulted in an effective protection against the challenge in all treated animals. After consumption of feed medicated with 125 mg per kg SMX or 25 mg per kg TMP, pleuropneumonia was evident in all challenged pigs. The results of this study indicate an in vivo potentiation of SMX and TMP in pigs against this respiratory tract pathogen.

Actinobacillus Infections↗
PubMed2000

Effects of ambient temperature, arginine-to-lysine ratio, and electrolyte balance on performance, carcass, and blood parameters in commercial male turkeys.

The effects of ambient temperature (T; 15 C vs. 30 C from 6 wk of age onwards), dietary Arg:Lys ratio (Arg:Lys ratio; 1.00 vs. 1.25), dietary electrolyte balance (DEB: 164 vs. 254 meq/kg), and their interactions on growth performance and carcass yields of male turkeys were studied. The experiment was designed as a split plot, including T x DEB as the main plot and Arg:Lys ratio as the sub-plot, with 24 pens containing 35 male turkeys each. Feed consumption, BW gain, mortality, and processing yields were measured. Temperature had a clear effect on performance during all age periods. Feed intake was significantly lower for the high T group compared with the low T group (322.7 vs. 432.3 g/bird per day; P < 0.001). Consequently, BW gain during the experimental period (28 to 140 d of age) was significantly lower for the high T group compared with the low T group (14.54 vs. 18.74 kg; P < 0.001). Feed:gain during the period of 28 to 140 d of age was significantly lower for the high T group compared with the low T group (2.51 vs. 2.61; P < 0.001). The high dietary Arg:Lys ratio increased feed intake significantly until 56 d of age (200.6 vs. 197.6; P < or = 0.034). A high Arg:Lys ratio resulted in significantly higher BW gain until 98 d of age (10.03 vs. 9.84 kg; P < or = 0.024). The Arg:Lys ratio did not affect feed:gain throughout the experiment. Dietary electrolyte balance did not affect performance parameters. No consistent two- or three-way interactions were observed. Processing yields were only affected significantly by T, and not by Arg:Lys ratio or DEB main effects. High T resulted in lower cold carcass (73.2 vs. 74.9%) and breast meat yields (33.5 vs. 36.0%), and higher thigh (18.9 vs. 18.1%), drumstick (14.5 vs. 13.2%), and wing yields (11.7 vs. 10.6%) compared with low T. We concluded that growth performance is compromised by higher T, and altering the Arg:Lys ratio or DEB does not alleviate this impaired performance. Dietary Arg levels seem to be important when dietary Lys is marginal relative to the requirement.

Animal Feed↗
PubMed1997

[Respiratory symptoms in meat pigs: is there a role for porcine respiratory corona virus (PRCV) and porcine reproductive and respiratory syndrome virus (PRRSV) in the etiology?].

On a pig farm with about 2000 pigs, respiratory problems regularly developed in fattening pigs 3 to 4 weeks after the start of the fattening period. A postmortem examination was carried out on four pigs during the acute phase of their illness. The animals showed signs of viral pneumonia. In two animals porcine respiratory virus (PRCV) was discovered and in the other two animals porcine reproductive and respiratory syndrome virus (PRRSV). The possible role of these two viruses in the aetiology of the health problems on this farm is discussed in the context of the results of a longitudinal serological study.

Animals↗
PubMed1996

[Pharmaceutical quality of amoxicillin-containing tablets for veterinary use].

Before a veterinary drug is licensed for the Dutch market it has to comply to basic pharmaceutical standards. From the results of this study, carried out in the Spring of 1995, it appeared that many amoxicillin-containing tablets marketed in Holland do not fulfil these requirements. Only one third of the preparations complied with all criteria set by us. The preparations investigated originated from eight licence holders. The preparations from two licence holders satisfied our criteria. When choosing a veterinary drug, veterinarians should be aware of the considerable differences in pharmaceutical quality.

Amoxicillin↗
PubMed1996

In-vivo buccal delivery of fluorescein isothiocyanate-dextran 4400 with glycodeoxycholate as an absorption enhancer in pigs.

Buccal delivery of fluorescein isothiocyanate labeled dextran 4400 (FD4) was investigated in-vivo in pigs. The delivery device consisted of an application chamber with a solution of FD4 and was adhered to the buccal mucosa for 4 h using an adhesive patch. A randomized crossover study including intravenous administration and buccal delivery without and with 10 mM sodium glycodeoxycholate (GDC) as absorption enhancer was performed in five pigs. After buccal administration, steady state plasma levels were rapidly reached. Coadministration of 10 mM GDC increased the absolute bioavailability of FD4 from 1.8 +/- 0.5% to 12.7 +/- 2.0%. Since FD4 is a macromolecular and hydrophilic compound such as peptide and protein drugs, buccal delivery would provide an adequate alternative to the parenteral administration of these drugs.

Absorption↗
PubMed1996

In vivo buccal delivery of the peptide drug buserelin with glycodeoxycholate as an absorption enhancer in pigs.

PURPOSE: To study the potential of buccal delivery of the peptide drug in pigs. METHODS: Intravenous administration and buccal delivery without and with 10 mM sodium glycodeoxycholate (GDC) as absorption enhancer were investigated as a randomised cross-over study in six pigs. The buccal delivery device consisted of an application chamber with a solution of buserelin and was attached to the buccal mucosa for 4 hours using an adhesive patch. RESULTS: Buccal administration of buserelin resulted in rapidly reached steady state plasma levels. The absolute bioavailability of the peptide after buccal delivery for 4 hours could be increased from 1.0 +/- 0.3 to 5.3 +/- 1.1% (mean +/- SD.) by co-administration of 10 mM GDC (0.45% w/v)). CONCLUSIONS: The results of this study demonstrate that buccal administration with the use of absorption enhancers is a useful approach for the delivery of peptide drugs such as buserelin.

Administration, Oral↗
PubMed1995

An observational study of Eimeria species in housed cattle on Dutch dairy farms.

The prevalence of oocysts of Eimeria species in calves (n = 334), yearlings (n = 254) and cows (n = 1314) was determined on 38 Dutch dairy farms. Twelve species of Eimeria were identified in faecal specimens by sucrose-flotation. The prevalences of Eimeria spp. differed markedly in the different age classes on individual farms as well as between farms. The overall prevalence of Eimeria oocysts in faecal specimens was 46% for calves, 43% for yearlings and 16% for cows. The number of oocysts excreted was generally low in cows and yearlings, whereas high numbers of oocysts per gram of faeces (OPG) were exclusively observed in calves. No cases of clinical coccidiosis were observed in this survey. Linear regression analysis showed that there is significant reduction in the OPG levels (P < 0.05) in calves infected with Eimeria, aged between 7 and 38 weeks. Finally, the data are discussed in relation to management practices and the acquisition of immunity.

Aging↗
PubMed1995

Pharmacokinetics of sulfadimethoxine and sulfamethoxazole in combination with trimethoprim after intravenous administration to healthy and pneumonic pigs.

The pharmacokinetics of two sulfonamide/trimethoprim combinations were investigated after intravenous administration to clinically healthy pigs and to the same pigs following a challenge with Actinobacillus pleuropneumoniae toxins. Endobronchial challenge with A. pleuropneumoniae toxins resulted in fever, increased white blood cell counts and decreased water and feed consumption. Healthy, as well as febrile, pigs were given sulfadimethoxine (SDM) or sulfamethoxazole (SMX) intravenously at a dose of 25 mg/kg b.w. in combination with 5 mg trimethoprim (TMP) per kg body weight. The pharmacokinetic parameters of the sulfonamides as well as their main metabolites (acetyl sulfonamides) were not significantly different in healthy and febrile pigs. In healthy and pneumonic pigs, the mean elimination half-lives of SDM were 12.9 h and 13.4 h, respectively, those of SMX 2.5 h and 2.7 h, respectively, and those of TMP 2.8 h and 2.6 h, respectively. Distribution volumes in healthy and febrile pigs of SDM and SMX varied between 0.2 and 0.4 L/kg, and those of TMP between 1.1 and 1.6 L/kg. The mean AUC of TMP was decreased and the volume of distribution and total body clearance of TMP were increased in febrile pigs. Protein binding of the drugs and metabolites studied were not significantly changed after toxin-induced fever. The extent of protein binding of SDM, SMX and TMP was in the range 94-99%, 45-56% and 40-50%, respectively. Based on knowledge of in vitro antimicrobial activity of the drug combinations against A. pleuropneumoniae it was concluded that after intravenous administration of the dose administered (30 mg/kg of the combination preparations) to healthy and pneumonic pigs, plasma concentrations of SMX and TMP were above the concentration required for growth inhibition of 50% of A., pleuropneumoniae strains for approximately 16 h, whereas bacteriostatic plasma concentrations of SDM were still present after TMP had been eliminated from plasma. Because of similar elimination half-lives of SMX and TMP in pigs this combination is preferred to the combination of SDM with TMP.

Actinobacillus Infections↗
PubMed1995

Selective effects of a bacterial infection (Actinobacillus pleuropneumoniae) on the hepatic clearances of caffeine, antipyrine, paracetamol, and indocyanine green in the pig.

1. In order to investigate the effect of a bacterial acute phase response model on drug disposition in vivo, plasma clearances of antipyrine, caffeine, paracetamol and indocyanine green were investigated in the healthy and Actinobacillus pleuropneumoniae-infected pig. 2. Indocyanine green plasma and endogenous creatinine clearance were not changed during the infection, which indicates that hepatic blood flow and renal function were not significantly affected. 3. In the A. pleuropneumoniae-infected pig, plasma clearances of antipyrine and caffeine, both marker substrates for hepatic oxidative biotransformation, were decreased by 72 and 68% respectively. The clearance of paracetamol, a drug mainly glucuronidated in the pig, was reduced by 39%. 4. It is concluded that the most important change in drug elimination during an acute phase response induced by A. pleuropneumoniae is a suppression of oxidative hepatic biotransformation.

Acetaminophen↗