Evaluation of bone response to various anorganic bovine bone xenografts: an experimental calvaria defect study

This in vivo study investigated the in vivo performance of two newly developed synthetic bone substitutes and compared them to commercially available xenografts (Bio-Oss, Geistlich Pharma AG, Switzerland; OsteoGraf, Dentsply, USA). The materials were tested in a rabbit calvaria model, and the bone forming properties were observed at 4 and 8 weeks after implantation by means of histomorphometry and micro computed tomography (micro-CT). Defects without any graft material were used as negative controls. Micro-CT showed that all materials tested presented new bone formation that filled the defects at both time points, whereas the negative control presented less bone formation, with soft tissue infiltration into the defects. Comparable bone fill percentages were observed for histomorphometric and micro-CT results. Even though no statistically significant difference was found quantitatively between all of the bone graft substitute groups, a higher mean decrease in graft material filling the defects, along with higher remodelling activity, was evident for the experimental materials compared to the commercially available xenografts at 8 weeks. The results indicate that the experimental materials possess high degradability, along with osteoconduction comparable to commercially available xenografts.

[Development of a nested polymerase chain reaction test for the diagnosis of transmissible gastroenteritis of pigs]

The aim of this study was to develop a nested polymerase chain reaction (nested PCR) for the rapid detection of transmissible gastroenteritis virus (TGEV) of pigs. The primers were designed on the basis of highly conserved regions of several TGEV sequences included in the analysis. External primers were used to amplify a fragment of the expected size (441 bp) in all the samples evaluated using reverse transcriptase polymerase chain reaction (RT-PCR), but with very low intensity. In the second amplification (nested PCR), internal primers were used to amplify a fragment of the expected size (168 bp), with good concentration. The performance of the test based on virus isolates in tissue culture and in clinical samples was judged good for the virological diagnosis of transmissible gastroenteritis of pigs.

SU-E-J-23: Prostate Bed Motion Study Using Surgical Clips Based on Daily CBCT

PURPOSE

To study prostate-bed motion after prostatectomy using the surgical clips as a surrogate.

METHODS

On the treatment planning CT, surgical clips within the PTV are identified and contoured. They are also identified and contoured in each daily CBCT. The center of mass (COM) coordinates for each clip within the native reference frame of each image set of CT and CBCT are recorded. Each CBCT (for daily image guidance) is registered to the planning CT based on the pelvic bony structure. The resulted 3D transformation matrix is used to convert the clip coordinates in the CBCT to the planning CT reference frame. Difference between the converted COM coordinates and the one in planning CT is taken as the rigid motion of the prostate bed relative to the pelvic bony structure during the course of radiation therapy. The motion data are then analyzed using statistical error analysis and quantified by the commonly defined M (average over all fractions and all patients), S (stdev of averages per patient, the systematic motion), and s (root mean square of stdev per patient, the random motion). Among a large pool of patients, seven patients were selected for this retrospective study, each with 3 to 11 identifiable clips and 17 to 26 CBCT sets. The total number of clips is 44 and total daily CBCT sets 160.

RESULTS

In the (right-left, anterio-posterior, foot-head) directions, the M values are (0.2 mm, 0.4 mm, -0.6 mm), S (0.2, 2.5, 3.2), and s (1.7, 2.6, 2.1).

CONCLUSIONS

Relative to the bony pelvic structure, the prostate bed motion characteristics are similar to that of intact prostate, as summarized in Table 2 of Rasch et al 2005 ('Target Definition in Prostate, Head, and Neck.' Semin Radiat Oncol 15:136-145).

Infection with a pathogenic turkey coronavirus isolate negatively affects growth performance and intestinal morphology of young turkey poults in Canada

Turkey coronavirus (TCoV) is an important viral pathogen causing diarrhoea of young turkey poults that is associated with sizeable economic losses for the turkey industry. Using a field isolate that was found to be free from turkey astrovirus and avian reovirus we were able to reproduce the clinical disease associated with TCoV. Clinical signs and weight gain of poults during experimental infections were compared with age-matched, uninfected controls. Poults infected at 2 days of age had 100% morbidity and 10% mortality, and birds infected at 28 days of age showed 75% morbidity and no mortality. Diarrhoea was consistently seen in infected poults at 2 to 3 days post infection (d.p.i.) with a duration of about 3 to 5 days. Mean body weights of birds infected at 2 or 28 days of age were significantly reduced compared with uninfected birds by 7 d.p.i. and remained significantly lower for the duration of the study. At 44 days of age, poults infected at 2 or 28 days of age weighed only 68.1% or 77.7%, respectively, compared with uninfected turkeys of the same age on the same diet, a mean difference in body weights of 683 or 477g, respectively. Infected birds had profound villus atrophy with some compensatory crypt hyperplasia at 5 to 7 d.p.i. Villus heights in the duodenum were significantly reduced at 7 d.p.i. We were able to reproduce enteric disease using only a pathogenic field isolate (MG10) of TCoV that negatively affected growth performance and intestinal morphology of young turkey poults.

Virus shedding and serum antibody responses during experimental turkey coronavirus infections in young turkey poults

The course of turkey coronavirus (TCoV) infection in young turkey poults was examined using a field isolate (TCoV-MG10) from a diarrhoeal disease outbreak on a commercial turkey farm in Ontario, Canada. Two-day-old and 28-day-old poults were inoculated orally with TCoV-MG10 to examine the effect of age on viral shedding and serum antibody responses to the virus. The presence of coronavirus particles measuring 105.8+/-21.8 nm in the cloacal contents was confirmed using transmission electron microscopy. The pattern of cloacal TCoV shedding was examined by reverse-transcription polymerase chain reaction amplification of the nucleocapsid gene fragment. TCoV serum antibody responses were assessed with two recently developed TCoV enzyme-linked immunosorbent assays that used TCoV nucleocapsid and S1 polypeptides as coating antigens. Poults were found equally susceptible to TCoV infection at 2 days of age and at 4 weeks of age, and turkeys of either age shed virus in their faeces starting as early as 1 day post-inoculation and up to 17 days post-inoculation. Poults infected at 2 days of age were immunologically protected against subsequent challenge at 20 days post-inoculation. The protection was associated with measurable serum antibody responses to both the nucleocapsid and S1 structural proteins of TCoV that were detectable as early as 1 week post-infection.

Highly virulent porcine reproductive and respiratory syndrome virus emerged in China

A highly pathogenic pig disease emerged in China in 2006, which was characterized by prolonged high fever, red discoloration of the body, and blue ears associated with high mortality. Porcine reproductive and respiratory syndrome virus (PRRSV) was isolated as the single most prominent virus in the samples collected from affected pigs. The full-length genomic sequence of the virus revealed two distinct deletions in the non-structural protein 2 (NSP2) in comparison to all previously reported North American genotype PRRSV. Through extensive surveys in 14 different provinces, 56 additional PRRSV isolates were obtained from affected farms. All of the isolates were found to contain identical deletions in NSP2. To confirm the etiology, eight 60-day-old PRRSV-free pigs were divided into two groups and the test group was intranasally infected at a titer of 2 x 10(5.0) tissue culture infectious dose 50 per pig. The inoculated pigs all died at 7, 8, 12, 16, or 21 days post-inoculation with their clinical and pathological findings similar to those in the field. The viruses recovered from dead pigs were identical to the inoculated virus in NSP2 and GP5 genes. Our study shows that the recently emerged PRRSV in China is characterized by two discontiguous deletions in NSP2 and is the cause for the current epizootics in China.

Complete genomic sequence of turkey coronavirus

Turkey coronavirus (TCoV), one of the least characterized of all known coronaviruses, was isolated from an outbreak of acute enteritis in young turkeys in Ontario, Canada, and the full-length genomic sequence was determined. The full-length genome was 27,632 nucleotides plus the 3′ poly(A) tail. Two open reading frames, ORFs 1a and 1b, resided in the first two thirds of the genome, and nine additional downstream ORFs were identified. A gene for hemagglutinin-esterase was absent in TCoV. The region between the membrane (M) and nucleocapsid (N) protein genes contained three potential small ORFs: ORF-X, a previously uncharacterized ORF with an associated putative TRS within the M gene (apparently shared among all group III coronaviruses), and previously described ORFs 5a and 5b. The TCoV genome is organized as follows: 5′ UTR – replicase (ORFs 1a, 1b) – spike (S) protein – ORF3 (ORFs 3a, 3b) – small envelop (E or 3c) protein – membrane (M) protein – ORF5 (ORFs X, 5a, 5b) – nucleocapsid (N) protein −3′ UTR – poly(A). TCoV genome structure and sequence was most similar, but distinct from, avian infectious bronchitis virus (IBV). This is the first complete genome sequence for a TCoV and confirms that TCoV belongs to group III coronaviruses.

Avian hepatitis E virus in an outbreak of hepatitis–splenomegaly syndrome and fatty liver haemorrhage syndrome in two flaxseed-fed layer flocks in Ontario

Two commercial layer chicken flocks that were fed a flax-based diet beginning at 28 weeks of age for the production of omega-3 fatty-acid-enriched eggs experienced increased mortality when the birds reached 37 weeks. The average weekly mortality was 0.34% over a 20-week period, with peak mortality of 0.9% for 1 week. Reduced feed consumption, reduced body weight gain and poor peak production were noticed prior to the onset of increased mortality. A total of 245 birds were necropsied and 78% of these had lesions in the liver and spleen, with 44% of those necropsied having changes consistent with hepatitis-splenomegaly syndrome, with lesions ranging from acute periportal lymphoplasmacytic hepatitis to chronic severe cholangiohepatitis with haemorrhage, vasculitis and amyloidosis. A total of 11% of the birds had lesions typical of fatty liver haemorrhagic syndrome, and 22% had lesions found in both hepatitis-splenomegaly syndrome and fatty liver haemorrhagic syndrome. No significant bacteria or viruses were recovered from samples of the liver/bile or spleen but 11 of 21 bile samples contained avian hepatitis E virus RNA detectable with a reverse transcriptase-polymerase chain reaction assay. Comparative sequence analysis found identities of 82 to 92% and 78 to 80% between the helicase and capsid protein genes, respectively, of the virus detected in this outbreak and those of other avian hepatitis E virus isolates, suggesting extensive genetic heterogeneity in avian hepatitis E viruses in Ontario flocks.

Comprehensive management of diffuse malignant peritoneal mesothelioma

AIMS

In the past, diffuse malignant peritoneal mesothelioma (DMPM) has been regarded as a terminal condition. The length of the survival was dependent upon the aggressive versus indolent biology of the neoplasm, nevertheless cure was not considered as a reasonable expectation and the overall median survival was approximately one year.

METHODS

A comprehensive literature review and a collection of pertinent data published on DMPM from the Washington Cancer Institute were used to construct this report.

RESULTS

Recent publications from Bethesda MD, New York, Milan Italy, Lyon France and Washington DC have shown a remarkable prolongation in the median survival of this group of patients with approximately half the patients alive at 5 years. These prolonged survivors were treated with an intensive local-regional treatment strategy that included cytoreductive surgery (CRS) with peritonectomy and hyperthermic intraoperative intraperitoneal chemotherapy (HIIC) and some patients with early postoperative intraperitoneal chemotherapy (EPIC). As larger numbers of patients have been treated, clinical features by which to select patients most likely to benefit from this approach have been identified. Also, as the experience in the management of patients receiving these treatments has increased, the morbidity and mortality associated with their management is being reduced.

CONCLUSIONS

A new standard of care involves surgical removal of large disease deposits combined with perioperative intraperitoneal chemotherapy. Knowledgeable management uses selection criteria and incurs low morbidity and mortality.

Significance of lymph node metastasis in patients with diffuse malignant peritoneal mesothelioma

BACKGROUND

Diffuse malignant peritoneal mesothelioma (DMPM) is a rare and invariably fatal neoplasm. Some studies have shown that cytoreductive surgery (CRS) combined with perioperative intraperitoneal chemotherapy (PIC) achieved an improved survival, as compared to historical controls. However, the significance of lymph node involvement in this disease has never been well defined.

METHODS

One hundred patients with DMPM underwent CRS and PIC at the Washington Hospital Center. The inclusion criteria for surgery consisted of histological diagnosis of DMPM, age <80 years and good performance status. All data were collected prospectively. Lymph node status, seven clinical variables and eight treatment-related prognostic factors were analyzed for survival.

RESULTS

Seven patients were lymph node positive and they all died of their disease within 2 years after the surgery. The remaining 93 patients had 5- and 7-year survival of 50% and 43%, respectively. Univariate analysis showed that gender (p<0.001), peritoneal cancer index (p=0.009), lymph node status (p<0.001), extra-abdominal invasion (p=0.026), histological type (p<0.001), intraoperative blood loss (p=0.035), completeness of cytoreduction (p<0.001), intraperitoneal chemotherapy regimen (p=0.041), and redo cytoreductive surgery (p=0.022) were significant for survival. Multivariate analysis demonstrated that female gender, lymph node metastasis not detected, epithelial type, and adequate cytoreduction were independently associated with an improved survival.

CONCLUSIONS

CRS and PIC showed an improved survival for DMPM, as compared to historical controls. Lymph node status along with three other prognostic variables was significant in the multivariate analysis.