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Biomedical subjects

H M Hafez

Publications and source records attributed to H M Hafez.

At least 19 recordsLinked to original sources
PubMed2006

Plasma chemistry reference values in hybrid falcons in relation to their species of origin.

Twenty-one blood chemistry parameters were determined in 127 peregrine falcons (Falco peregrinus), 79 gyr-peregrine hybrids and 166 gyr-saker hybrids. These parameters, together with those previously established in 53 gyr falcons (Falco rusticolus) and 234 saker falcons (Falco cherrug), were compared. There were statistically significant differences in 15 of the parameters between the saker and peregrine falcons; the saker and gyr falcons; the saker and gyr-saker hybrids; the peregrine and gyr falcons; and the peregrine and gyr-peregrine hybrids, but not between the gyr falcons and the gyr-saker falcon hybrids.

Animals↗
PubMed2006

Detection of Histomonas meleagridis DNA in different organs after natural and experimental infections of meat turkeys.

Histomonas meleagridis infection of turkeys is usually accompanied by a severe disease with unspecific clinical symptoms but with distinct pathological lesions in the ceca and liver. In the literature some macro- and microscopic evidence of the spread of histomonads to the other organs has been provided. The aim of the present investigations was to use real-time polymerase chain reaction (PCR) to demonstrate the dissemination of H. meleagridis DNA to different organs after natural and experimental infection of meat turkeys. Samples from several organs were collected from a meat-turkey flock, which proved to be naturally infected with histomoniasis, and examined for histomonad DNA by real-time PCR. Histomonad DNA was detected in all investigated ceca, livers, spleens, kidneys, and pooled brain swabs. Additionally it was found in 75% of investigated samples from bursae of Fabricius, in 50% of investigated duodenums, and in 40% of investigated jejunum samples. After experimental intracloacal infection of 3-wk-old turkey poults with 147,500 histomonads, similar samples were collected from all turkeys that died. After a 3-wk observation period the surviving birds, as well as the noninfected control group, were euthanatized and samples were taken. During the entire experimental period, 10 birds out the 20 infected birds died. Histomonad DNA was detected in all investigated ceca, livers, lungs, and hearts (100%) and almost all kidneys (90%) and bursae of Fabricius (80%). On the other hand, only 30% of examined spleens and 10% of brain samples revealed positive results. Surviving infected birds were euthanatized and necropsied; histomonad DNA was found in one out of 10 livers but not in any ceca. Also, histomonad DNA could not be detected in examined cecal and lung samples from the noninfected control group.

Animals↗
PubMed2006

Isolation and molecular biological investigations of avian poxviruses from chickens, a turkey, and a pigeon in Croatia.

In the last 3 yr, several outbreaks of avian poxviruses (APVs) have been observed in different parts of Croatia. Four strains of APVs, from chickens, a pigeon, and a turkey, were isolated from cutaneous lesions by inoculation onto the chorioallantoic membranes (CAM) of 12-day-old specific-pathogen-free chicken embryos. The resulting proliferative CAM lesions contained eosinophilic cytoplasmic inclusion bodies. The characteristic viral particles of poxvirus were detected in the infected CAM and also in the infected tissues by transmission electron microscopy. Further identification and differentiation of the four various APVs were carried out by the use of a polymerase chain reaction (PCR) combined with restriction enzyme analysis. Using one primer set, which framed a region within the APV 4b core protein gene, it was possible to detect APV-specific DNA from all four tested isolates. PCR results revealed no recognizable differences in size of amplified fragments between the different APVs from chickens, turkey, and pigeon. Restriction enzyme analysis of PCR products using NlaIII showed the same cleavage pattern for turkey and chicken isolates and a different one for the pigeon isolate. Multiplex PCR for direct detection of APV and reticuloendotheliosis virus (REV) was carried out to determine the possible integration of REV in the genome of isolated APVs. The obtained results revealed that REV was present in chicken and turkey strains of poxviruses, whereas the pigeon isolate was negative. It is not known whether the avipoxvirus vaccine strain used in Croatia is contaminated with REV or if the REV is naturally contaminating Croatian field strains of fowl poxvirus. The latter is indicated by the negative REV finding in the pigeon, which was not vaccinated. The results of the present study indicate the reemergence of fowlpox in Croatia, where infections have not been recorded since 1963 and never confirmed etiologically.

Animals↗
PubMed2006

[Comparative studies on detection of Chlamydophila psittaci and Chlamydophila abortus in meat turkey flocks using cell culture, ELISA, and PCR].

The prevalence of chlamydia in 10 meat turkey flocks was investigated. As samples served of each moment of collection and sex of the animals 10 cloacal swabs which were taken at the age of 1, 4, 8 and 12 (females) or 16 weeks (males) and at the time of slaughter at the age of 16 or 20 weeks. Spleen samples were taken at the time of slaughter, additionally. These were pooled making 1 pool out of 5 individual samples. The cloacal and spleen pools were examined by nested PCR (nPCR), Capture-ELISA and Capture Blocking-ELISA directly as well as after isolation attempts in cell cultures. The most sensitive method to detect chlamydia, with 6 isolates proved to be the isolation by cell culture followed by detection using nPCR. Not corresponding to the results of the nPCR were 4 positive reactions found by the Capture-ELISA which could in no case be affirmed by Capture-Blocking-ELISA. The direct examination of cloacal swab pools by nPCR proved positive in only 2 cases. In contrast to this the examination of these samples by Capture-ELISA showed a high percentage of 71.9% positive results, of which only 2 cases were confirmed by nPCR and none by Capture-Blocking-ELISA. Of the 8 Chlamydia positive results in the nPCR 7 could be classified by DNA sequencing to Cp. abortus and only one to Cp. psittaci.

Animals↗
PubMed2005

Key role of Chlamydophila psittaci on Belgian turkey farms in association with other respiratory pathogens.

Two hundred turkey sera from eight Belgian and two French farms were tested for the presence of antibodies against avian pneumovirus (APV), Ornithobacterium rhinotracheale (ORT), Mycoplasma gallisepticum, Mycoplasma meleagridis and Chlamydophila psittaci. At slaughter, C. psittaci, APV and ORT antibodies were detected in 94, 34 and 6.5% of the turkeys, respectively. No antibodies against M. gallisepticum or M. meleagridis were present. Additionally, turkeys on three Belgian farms were examined from production onset until slaughter using both serology and antigen or gene detection. All farms experienced two C. psittaci infection waves, at 3-6 and 8-12 weeks of age. Each first infection wave was closely followed by an ORT infection starting at the age of 6-8 weeks, which was still detectable when the second C. psittaci infection waves started. Animals on farm A were not vaccinated against APV leading to an APV subtype B outbreak accompanying the first C. psittaci infection wave. Despite subtype A APV vaccination on farms B and C, the second C. psittaci infection waves were accompanied (farm B) or followed (farm C) by a subtype B APV infection. On all farms respiratory signs always appeared together with a proven C. psittaci, APV and/or ORT infection. This study suggests an association between C. psittaci, APV and ORT, and indicates the multi-factorial aetiology of respiratory infections in commercial turkeys. All three pathogens should be considered when developing prevention strategies for respiratory disease.

Age Factors↗
PubMed2005

Comparison of the specificity and sensitivity of PCR, nested PCR, and real-time PCR for the diagnosis of histomoniasis.

Blackhead, also known as enterohepatitis, is caused by a protozoan parasite called Histomonas meleagridis. Clinical symptoms are nonspecific. Until now, diagnosis has been mainly based on postmortem lesions and microscopical and histopathological examination. In many cases, especially in layer flocks, these conventional methods are not sufficient, as the lesions are sometimes not clear. The technique for isolation of histomonads in vitro offers many advantages, but the confirmation of histomonads growing in culture may require a time-consuming procedure of rectal inoculation of culture material into chickens or turkeys. The aim of our investigation was to establish a conventional polymerase chain reaction (PCR), a nested PCR, and a real-time PCR, and to examine their specificity as well as sensitivity in the diagnosis of histomoniasis. The obtained results have shown that the conventional PCR is more sensitive than the real-time PCR. Furthermore, the sensitivity of the PCR can be increased by adding the nested PCR. However, the real-time PCR is more specific.

Amino Acid Sequence↗
PubMed2004

Differentiation of avian poxvirus strains on the basis of nucleotide sequences of 4b gene fragment.

Investigations for detection and differentiation of nine avian poxviruses (APVs) were carried out by the use of a polymerase chain reaction (PCR) combined with restriction enzyme analysis (REA) and further nucleotide sequence analysis. With one primer set, which framed a region within the fowl poxvirus 4b core protein gene, we were able to detect APV-specific DNA from 19 tested strains and isolates belonging to five defined Avipoxvirus species and four previously undefined isolated species. PCR results revealed no recognizable differences in size of amplified fragments among the different APVs. REA of PCR products with MseI and EcoRV allowed us to differentiate most of the tested avipox species. Nucleotide sequence analysis of the amplified fragments showed a nucleotide similarity of 72%-100% among the different species. Phylogenetic analysis documented five distinguishable sequence clusters in accordance with results obtained by REA. PCR in combination with REA and sequencing of the amplified fragments is a rapid and effective diagnostic system, and it is a new approach to refine epidemiologic studies of APV infections.

Animals↗
PubMed2003

Safety assessment of Bt 176 maize in broiler nutrition: degradation of maize-DNA and its metabolic fate.

Insect resistant Bt 176 maize has been developed by genetic modification to resist European borer infection. In the present investigation, the experiment was conducted to determine the effect of feeding a new hybrid of Bt 176 maize (NX 6262- Bt 176) on general health condition and performance of broiler chickens. Maize grains and diets were subjected to proximate analysis. Amino and fatty acids investigation were applied for both maize grains before used. To evaluate the degradation of NX 6262- Bt 176 maize DNA and its metabolic fate in broiler blood, muscles and organs. One-day-old male broilers were fed ad libitum on either an experimental diet containing NX 6262- Bt 176 or a control diet containing the non-modified maize grains for 35 days. Feed consumption and body weight were recorded weekly during the experimental period. All chickens were subjected to nutritional evaluation period at day 20 of age for 5 successive days, to calculate the percentage of apparent digestible nutrients in both diets. At day 35 samples were collected at several intervals after feed withdrawal. Prior to slaughter blood samples were collected from all birds by heart puncture to prevent DNA cross contamination. Samples from pectoral and thigh muscles, liver, spleen, kidney, heart muscle, bursa and thymus glands were collected. Digesta from different sections of the gastrointestinal tract (GIT) were collected as well. Packed cell volume (PCV) and some serum parameters were investigated. There were no significant differences between control and experimental group concerning chemical composition of feeds, apparent digestible nutrients, and all performance parameters measured (P > 0.05). Furthermore, there were no differences in the PCV and the analysed serum parameters between the control and experimental group. The results of maize DNA digestibility showed that the new variety takes the normal physiological passage along broiler GIT similar to the conventional line. In addition, Bt 176 maize DNA appears to be partially degraded in different parts of GIT comparable to the DNA of the control maize line. Results of the metabolic fate of maize DNA in broiler blood, muscles and organs indicated that only short DNA fragments (199 bp) derived from the plant chloroplast gene could be detected in the blood, skeletal muscles, liver, spleen and kidney, which disappeared after prolongation the fasting time. In heart muscle, bursa of Fabricius and thymus, no plant chloroplast DNA was found. Bt gene specific constructs from Bt 176 maize were not detected in any investigated blood or tissue samples.

Animal Feed↗
PubMed2002

The use of PCR combined with restriction enzyme analysis to characterize fowl adenovirus field isolates from northern India.

Ten fowl adenoviruses (FAVs), isolated from suspected cases of inclusion body hepatitis (IBH) in quails and broilers, were characterized by a hexon-based polymerase chain reaction (PCR) combined with restriction enzyme analysis (REA) of the amplified DNA fragments. All the isolates could be detected using H1/H2 and H3/H4 primer sets. Amplification of DNA with H1/H2 and H3/H4 primer sets resulted in fragments of approximately 1219 bp and 1319 bp, respectively. HaeII digestion of the H1/ H2 PCR products and HpaII digestion of the H3/H4 PCR products characterized all the isolates in FAV groups, known from genomic typing using the whole DNA. For some of the isolates, neutralization tests were used to confirm these results. The results revealed that, as well as FAV serotype 1, which is the sole member of DNA group A, FAVs of DNA group E are also associated with IBH in poultry in northern India. The FAV specific PCR combined with REA was found to be very useful in investigating the epidemiological situation in the field. It was even possible to define mixed infections with more than one FAV.

Adenoviridae Infections↗
PubMed2002

A fiber gene-based polymerase chain reaction for specific detection of pigeon adenovirus.

A polymerase chain reaction (PCR) was developed to detect a recently described pigeon adenovirus (PiAV). Primers located in the fiber gene of PiAV amplified a PCR fragment solely from PiAV DNA, whereas all 12 serotypes of fowl adenoviruses (FAV1 to FAV12), some of them able to infect pigeons, did not react. A PCR fragment of 967 base pairs was amplified from three different isolates serologically typed as PiAV and from some pigeon liver samples showing morphological and histological signs of an adenovirus infection. Those samples did not react with a published primer pair (H3/H4) able to detect FAV, demonstrating the specificity of both PCRs to react exclusively with the respective pathogen, PiAV or FAV. The presented PCR is a suitable diagnostic tool to gain further insight into the epidemiology of PiAV infections in pigeons.

Adenoviridae Infections↗
PubMed2001

Serological investigations on reticuloendotheliosis in turkey flocks.

Four meat turkey and one turkey breeding flocks were surveyed for antibodies against reticuloendotheliosis virus (REV) at different intervals using commercial enzyme-linked immunosorbent assays. In addition, serum samples collected from 18 flocks at different ages were also tested for antibodies against REV. No antibodies were detected in any of the four meat turkey flocks that were surveyed. In the breeder flock, 20%) of tested samples from 1-day-old poults were positive. Between the fourth and 12th weeks all samples that were tested yielded negative results. At 16 weeks of age 15% of samples yielded a positive reaction, but antibodies could not be detected 4 weeks later. Examination of serum samples from 18 different flocks at various ages revealed that antibodies could be detected in five flocks. The percentage of positive sera per flock ranged between 10 and 40%.

Animals↗
PubMed2001

Lower extremity arterial injury: results of 550 cases and review of risk factors associated with limb loss.

PURPOSE: We sought to analyze the results of lower limb arterial injury (LLAI) management in a busy metropolitan vascular unit and to identify risk factors associated with limb loss. PATIENTS AND METHODS: Between 1987 and 1997, prospectively collected data on 550 patients with 641 lower limb arterial injuries were analyzed. RESULTS: The mechanism of LLAI was gunshot wounds in 46.1%, blunt in 19%, stabbing in 11.8%, and shotgun in 9.1%. The most frequently injured vessel was the superficial femoral artery (37.2%), followed by the popliteal (30.7%), crural (11%), common femoral (8.7%), and deep femoral (5.3%) arteries. In 3.4% of cases, there was a combined injury on either side of the knee (ipsilaterally). Associated injuries included bony injury in 35.1% of cases, nerve injury in 7.6%, and remote affecting the head, chest, or abdomen in 3.6%. Surgery was carried out on 96.2% of cases with a limb salvage rate of 83.8% and a survival of 98.5%. In spite of a rising trend in LLAI, our total and delayed amputation rates remained stable. On stepwise logistic regression analysis, significant (P <.01) independent risk factors for amputation were occluded graft (odds ratio [OR] 16.7), combined above- and below-knee injury (OR 4.4), tense compartment (OR 4.2), arterial transsection (OR 2.8), and associated compound fracture (OR 2.7). CONCLUSION: LLAI carries a high amputation rate. Stab injuries are the least likely to lead to amputations, whereas high-velocity firearm injuries are the most likely to do so. The most significant independent risk factor for limb loss was failed revascularization.

Adolescent↗
PubMed2000

Presence of avian pneumovirus type A in continental Europe during the 1980s.

Three isolates of avian pneumovirus (APV) were isolated in Germany during 1987 and 1988 from turkeys with clinical signs of turkey rhinotracheitis and one was isolated during 1990 from a broiler breeder flock with typical signs of swollen head syndrome. The isolates were typed using type-specific reverse transcriptase-polymerase chain reactions. The three isolates from turkeys were identified as type A, while the isolate from the broiler breeders was type B. During the late 1980s no APV live-virus vaccine was used in poultry flocks in Germany, which is indicative of the presence of both types at that time. Previous isolates detected from elsewhere in Europe during the 1980s had been only of type B.

Animals↗
PubMed2000

Enhancing venous outflow in the lower limb with intermittent pneumatic compression. A comparative haemodynamic analysis on the effect of foot vs. calf vs. foot and calf compression.

OBJECTIVES: intermittent pneumatic compression (IPC), an established method of deep-vein thrombosis prophylaxis, is also an effective means of leg inflow enhancement, improving the walking capacity and ankle pressure of claudicants, long-term. This study, using duplex ultrasonography, compares the haemodynamic effect of IPC of the (a) foot (at 120 mmHg [IPC(foot/120 mmHg)], and 180 mmHg [IPC(foot/180 mmHg)]), (b) calf (IPC(calf), 120 mmHg) and (c) both simultaneously (IPC(foot+calf), 120 mmHg), on the venous outflow of 20 legs of normals and 25 legs of claudicants. RESULTS: the peak and mean velocities, volume flow and pulsatility index in the superficial femoral and popliteal veins of both groups increased significantly with all IPC modes (p<0.001). IPC(foot+calf)produced the highest enhancement followed by IPC(calf)(p<0.01), which was more effective (p<0.001) than either IPC(foot/180 mmHg)or IPC(foot/120 mmHg). The venous volume expelled with IPC(calf)and IPC(foot+calf)was 2-2.5 and 3-3.5 times that with IPC(foot/180 mmHg)respectively. Velocity enhancement with IPC was similar between groups and the superficial femoral and popliteal veins. IPC(foot/180 mmHg)produced higher (p<0. 01) flow velocities than IPC(foot/120 mmHg)in both groups and veins examined; however, differences were limited. CONCLUSIONS: all IPC modes proved effective, IPC(foot+calf)generating the highest venous outflow enhancement. Higher venous volumes expelled with IPC(foot+calf)explain its reported superiority on leg inflow over the other modes. Increase of applied pressure from 120 to 180 mmHg with IPC(foot)offered only a small outflow improvement. Venous haemodynamics at rest and with IPC in claudicants do not differ significantly from those in healthy subjects.

Adult↗
PubMed2000

Myocardial injury in major aortic surgery.

PURPOSE: The purpose of this study was to examine the effects of major aortic surgery and its associated oxidative stress and injury on the myocardium. METHODS: Plasma from 27 patients who underwent thoracoabdominal aortic aneurysm (TAAA) repair and 17 patients who underwent infrarenal aortic aneurysm (AAA) repair was collected at incision, aortic crossclamping, and reperfusion and 1, 8, and 24 hours thereafter. Samples were assayed for the myocardial specific protein troponin-T, total antioxidant status, and lipid hydroperoxides. RESULTS: Ten patients experienced cardiac dysfunction in the first 24 hours after surgery (eight patients in the TAAA group and two patients in the AAA group). Immediately after reperfusion, total antioxidant status levels dropped in all patients with TAAA and with AAA; this was more marked in patients with TAAA, leading to a significant difference between the two groups at this time point and for up to 1 hour thereafter (P <.01). Patients with TAAA showed a sharp rise in lipid hydroperoxide levels immediately after reperfusion, and levels were significantly higher than in patients with AAA (P =.0007). In patients with AAA, no significant change in troponin-T was observed throughout the study period; whereas in patients with TAAA, levels were significantly elevated at 8 and 24 hours after reperfusion (P <.01). Troponin-T levels significantly correlated with total antioxidant status (r = -0.5) and lipid hydroperoxides (r = 0.78) but not with systolic blood pressure. CONCLUSION: Supracoeliac aortic crossclamping is associated with a significant release of the myocardial injury marker troponin-T. This seems to correlate with the severity of oxidative rather than hemodynamic stresses. Ameliorating oxidative injury during TAAA surgery may therefore have a cardioprotective effect.

APACHE↗
PubMed2000

Endotoxemia during supraceliac aortic crossclamping is associated with suppression of the monocyte CD14 mechanism: possible role of transforming growth factor-beta1.

PURPOSE: Monocyte CD14 and its soluble form (sCD14) mediate the proinflammatory response to endotoxemia. The aim of this study was to measure the changes to these factors after major aortic surgery and the possible inhibitory role of transforming growth factor-beta(1) (TGF-beta(1)) during these procedures. METHODS: Twenty-four patients with supraceliac aortic crossclamping during thoracoabdominal aortic aneurysm (TAAA) repair and 12 patients with infrarenal aortic crossclamping as part of infrarenal aneurysm repair (AAA) were studied. Blood was collected at incision, aortic clamping, and reperfusion and at 1, 8, and 24 hours after reperfusion. Samples were assayed for endotoxin, peripheral blood monocyte CD14 expression, sCD14, tumor necrosis factor-alpha, and TGF-beta(1). RESULTS: Although there was significant endotoxemia on reperfusion in both groups of patients, peak plasma endotoxin levels were significantly higher in patients with TAAA (P =.001). Monocyte CD14 and plasma sCD14 were significantly decreased in patients with TAAA at reperfusion and 1 hour after reperfusion (P <.01, both points). In patients with AAA, a significant upregulation of CD14 was observed at 24 hours after reperfusion (P <.01), but no significant changes in sCD14 were observed. TNF-alpha showed no significant changes during the study period in both groups. In patients with TAAA, TGF-beta(1) showed significant elevation at all time points (P <.01); whereas in patients with AAA, TGF-beta(1) showed no significant changes. CONCLUSION: Splanchnic ischemia reperfusion in patients who undergo supraceliac aortic clamping is associated with peripheral blood monocyte CD14 suppression and significant elevation of TGF-beta(1). TGF-beta(1) may play an important role in modulating the immune response to endotoxemia during major aortic aneurysm surgery.

Aged↗
PubMed2000

Efficacy of ELISA for detection of antibodies against several Ornithobacterium rhinotracheale serotypes.

The present investigation were carried out to compare self-made ELISA based on SDS-Antigen extraction of serotype B and one commercial ELISA-kit (Biocheck, Gouda, The Netherlands) for their ability to detect antibodies against 12 ORT serotypes (A-L). Using both ELISA systems, antibodies against all serotypes were detected. Examination of serum samples collected from commercial flocks showed similar results on flock bases. However, some minor variations on sample basis could be demonstrated. In conclusion using both ELISA system antibodies against different serotypes could be detected.

Animals↗