Virus characterization, clinical presentation, and pathology associated with H7N3 avian influenza in British Columbia broiler breeder chickens in 2004.

Low-pathogenicity avian influenza (LPAI) subtype H7N3 was diagnosed on a two-age broiler breeder farm in Abbotsford, British Columbia (BC), in early February 2004. The presenting complaint in the older index flock was feed refusal, with 0.5% mortality over 72 hr that resolved over the following week Ten days after the initial complaint in the index flock, a younger flock in an adjacent barn experienced an abrupt spike in mortality (25% in 48 hr). The gross lesions of tracheal hyperemia and hilar pulmonary consolidation were subtle and nonspecific, and the diagnosis of avian influenza required laboratory confirmation. Two different viruses were isolated from the index farm: a LPAI (H7N3) was isolated from the older flock and a high-pathogenicity avian influenza (HPAI) (H7N3), which had an additional 21 base insertion at the hemagglutinin-cleavage site, was isolated from the younger flock. The presence of this insertion sequence and the similarity of adjacent sequences indicate that the LPAI had mutated into HPAI at some point between the first and second barn. Despite enhanced on-farm biosecurity measures, the virus was not contained on the index farm and eventually spread to over 40 commercial poultry facilities before massive depopulation efforts enabled its eradication.

Infusion of dendritic cells pulsed with HLA-A2-specific prostate-specific membrane antigen peptides: a phase II prostate cancer vaccine trial involving patients with hormone-refractory metastatic disease.

BACKGROUND: A phase II trial was conducted to assess the efficacy of infusions of dendritic cells (DC) and two HLA-A2-specific PSMA peptides (PSM-P1 and -P2). This report describes thirty three subjects with hormone-refractory metastatic prostate cancer without prior vaccine therapy history who were evaluated and reported as a group. METHODS: All subjects received six infusions of DC pulsed with PSM-P1 and -P2 at six week intervals. Clinical monitoring was conducted pre-, during, and post- phase II study. Data collected include: complete blood count, bone and total alkaline phosphatase, prostate markers, physical examination, performance status, bone scan, ProstaScint scan, chest x-ray, as well as assays to monitor cellular immune responses. RESULTS: Six partial and two complete responders were identified in the phase II study based on NPCP criteria, plus 50% reduction of prostate-specific antigen (PSA), or resolution in previously measurable lesions on ProstaScint scan. CONCLUSIONS: Over 30% of study participants in this group showed a positive response at the conclusion of the trial. This study suggested that DC-based cancer vaccines may provide an alternative therapy for prostate cancer patients whose disease no longer responds to hormone therapy.

Evaluation of phase I/II clinical trials in prostate cancer with dendritic cells and PSMA peptides.

BACKGROUND: A phase I trial involving patients with advanced prostate cancer was conducted to assess the safe administration of dendritic cells (DC) and HLA-A0201-specific prostate-specific membrane antigen (PSMA) peptides (PSM-P1 or -P2). Thirty-three of the phase I participants were subsequently enrolled in a phase II trial, which involved six infusions of DC pulsed with PSM-P1 and -P2 peptides. METHODS: Clinical monitoring was conducted up to 770 days from the start of the phase I study. Data collected included: complete blood count, bone and total alkaline phosphatase, prostate markers, physical examination, performance status, bone scan, ProstaScint scan, and chest X-ray, as well as assays to monitor cellular immune responses. RESULTS: Nine partial responders were identified in the phase II study based on National Prostate Cancer Project (NPCP) criteria, plus 50% reduction of prostate-specific antigen. Four of the partial responders were also responders in the phase I study, with an average response duration of 225 days. Their combined average total response period was over 370 days. Five other responders were nonresponders in the phase I study. Their average partial response period was 196 days. CONCLUSIONS: The responses observed in the phase I and II clinical trials were significant and of long duration. The partial-responder group included patients who continued to respond from phase I, as well as those who started to respond during the phase II trial.

Comparison of serum PSMA, PSA levels with results of Cytogen-356 ProstaScint scanning in prostatic cancer patients.

BACKGROUND: Stored serum from clinical trial cases undergoing ProstaScint (CYT-356) scanning were available for Prostate Specific Membrane Antigen (PSMA) assay. Prostate Specific Antigen (PSA) levels had already been determined. This provided an opportunity to see what correlations existed between the serum markers and the ProstaScint scan. A group of patients had the studies preprostatectomy, whereas another group had the studies postprostatectomy. METHODS: The scan results, serum PSA, serum PSMA, and clinical data were separately analyzed. PSMA serum levels were determined by Western blot. RESULTS: Preoperatively, radical prostatectomy patients showed a correlation between serum PSA or PSMA levels and the ProstaScint scan in the total group (n = 86), or in an untreated group (n = 38). Preoperatively, PSMA correlated with the pathological stage, whereas PSA correlated with the scan. Postoperatively, only PSMA serum levels correlated with the scan in an untreated group (n = 40). CONCLUSIONS: Preoperatively or postoperatively, Western blot PSMA serum levels predict the stage of disease or local, regional, or distant metastases, as shown by ProstaScint scan. Both the scan and the serum tests provide prognostic information and evaluate the extent of disease to a more significant degree than previously possible.

Evaluation of PSA, free PSA, PSMA, and total and bone alkaline phosphatase levels compared to bone scans in the management of patients with metastatic prostate cancer.

BACKGROUND: Metastatic prostate cancer clinical evaluation is difficult. A revaluation of new prostate markers with regard to bone scans was performed. METHODS: Serial markers, including bone alkaline phosphatase (BAP), total alkaline phosphatase (TAP), prostate-specific antigen, total (PSA) and free (fPSA), and prostate-specific membrane antigen (PSMA), were obtained in patients under evaluation and treatment for possible or known metastatic prostate cancer. These were correlated with bone scan results (BSR). RESULTS: Seventy patients were observed from mid-October 1996-January 1997, during which time 171 serum samples were obtained and correlated with semiquantitative bone scan status. PSA and fPSA provided some correlation with BAP and BSR, but only at high levels (> 16-50 ng/ml). Receiver-operating curve (ROC) analysis demonstrated that BAP and TAP had a significant discriminating ability for positive and negative bone scans (> .78), compared to PSMA, PSA, and fPSA. However, percent BAP and TAP only correlated with BSR at a level above six lesions. As the lesions detected by BSR increased, the correlation increased. CONCLUSIONS: BAP is a valuable marker for clinical response evaluations to use in the serial follow-up of patients with metastatic prostate cancer, and correlates well with the bone scan as the number of lesions increase to > 6. PSA or fPSA show comparable results, but only at high levels (> 16-50 ng/ml).

Follow-up evaluation of prostate cancer patients infused with autologous dendritic cells pulsed with PSMA peptides.

BACKGROUND: We recently conducted a phase I clinical trial administering autologous dendritic cells pulsed with prostate-specific membrane antigen (PSMA) peptides to advanced prostate cancer patients. Participants were divided into 5 groups receiving 4 or 5 infusions of peptides alone (PSM-P1 or -P2; groups 1 and 2, respectively), autologous DC (group 3), or DC pulsed with PSM-P1 or -P2 (groups 4 and 5, respectively). Seven partial responders were observed. Follow-up evaluation of these responders is presented in this report. METHODS: Clinical monitoring for hematological studies and prostate markers was conducted up to 370 days from the start of the phase I study. Data collected include: lymphocyte, hematocrit, alkaline phosphatase, prostate-specific antigen (PSA), free PSA, and PSMA levels. RESULTS: Groups 4 and 5 (patients infused with DC pulsed with PSM-P1 or -P2) represented 5/7 responders. The length of response was between 100 days (1 patient) to 200 days or above (6 patients). Four patients still remained responsive at the end of the period of observation. CONCLUSIONS: The responses observed in this phase I clinical trial are significant and of long duration. Most of the responders were in treatment groups infused with DC pulsed with PSM-P1 or -P2, suggesting the requirement of both components for effective immunotherapy.

Cancer immunotherapy for prostate cancer.

Our approach to prostate cancer immunotherapy involves two components dendritic cells as antigen-presenting cells; and the antigen used to target T-cell attack, HLA-A0201-associated peptides from prostate specific membrane antigen (PSMA). We have conducted a phase I dose-ranging study in 51 men with advanced prostate cancer, using dendritic cells pulsed with a PSMA peptide. no significant toxicity was observed. In that study, T-cell response was enhanced, with seven men meeting NCPC and PSA criteria for partial response. We are now conducting a phase II study with 67 men, who will receive 6 infusions of dendritic cells that have been pulsed with 2 PSMA peptides, at 6-week intervals. The phase II study design and rationale is described in this paper.

Evaluation and comparison of two new prostate carcinoma markers. Free-prostate specific antigen and prostate specific membrane antigen.

BACKGROUND: Two new prostate cancer markers, free-prostate specific antigen (f-PSA) and prostate specific membrane antigen (PSMA) were recently introduced. This report summarizes a prospective two-year multicenter test of their diagnostic or prognostic capabilities. Total PSA was also measured. METHODS: There were four clinical groups studied: (1) 226 individuals from a screening project undergoing ultrasound and biopsy evaluation had markers obtained: (2) 68 patients suspected of having prostate cancer and undergoing 2 or more biopsies had the markers obtained on multiple occasions: (3) 100 patients undergoing radical prostatectomy had markers obtained pre- and post-operatively: and (4) 31 patients with metastatic prostate cancer each had multiple samples for marker assay obtained over a 2-year period. In all, 465 patients had one or more samples obtained and studied. RESULTS: Free-PSA affords little additional diagnostic advantage compared with total PSA in the screening population. The receiver operating characteristic curves for diagnostic accuracy were ranked: (1) PSA density; (2) total PSA; (3) f-PSA; and (4) PSMA, PSMA showed the best correlation with stage of the primary tumor in the screened group. In the multiple negative biopsy group, f-PSA varied from 12 to 21%. PSMA values were evaluated in all histologic categories. PSA density was > or = 0.15 in all categories. In the prostatectomy cases PSA values postoperatively were quite low in Stage II; f-PSA was of no value. Later, f-PSA was increased in association with elevated total PSA values. Mean PSMA values were above normal in all postoperative time periods except in Stage III patients at 6 months to 1 year postoperatively. PSA densities were all > or = 0.15. In patients with metastatic carcinoma, elevated PSMA values correlated best with a poor prognosis (clinical progression), as has been described. CONCLUSIONS: These data suggest that f-PSA values do not provide additional diagnostic benefit compared with total PSA in screening populations, in the presence of suspected cancer, postprostatectomy, or in metastatic disease. PSMA is of prognostic significance, especially in the presence of metastatic disease, and correlates well with the stage of disease in cancers detected in a screened population.

Measurement of prostate-specific membrane antigen in the serum with a new antibody.

Work to date has identified prostate-specific membrane antigen (PSMA) as a membrane-bound glycoprotein with high specificity for prostatic epithelial cells. PSMA reacts with the monoclonal antibody 7E11.C5, which is present in serum, seminal fluid, and prostatic epithelial cells, and is increased in its expression in the presence of a hormone refractory state associated with prostatic cancer. This report confirms these results and further documents the presence of the monoclonal antibody 3F5.4G6, which reacts with the extracellular domain of PSMA. This region of PSMA is also an element present in a truncated version of the protein, so-called PSM'. Immune precipitation with either 7E11.C5 or 3F5.4G6 yields an isolated protein species that are reactive with the reciprocal antibody in Western blot analysis. Thus, 3F5.4G6 recognizes the same PSMA protein as does 7E11.C5, but at different epitopes on essentially opposite ends of the molecule. These two antibodies are well suited for use in a sandwich immunoassay, either one as a capture or detection antibody. Current work on this is underway. This report also confirms that 7E11.C5 Western blots for PSMA are negative with normal human brain tissue. The monoclonal antibody 9H10 does not react with 3F5.4G6 or with 7E11.C5 in studies conducted herein. Moreover, 3F5.4G6 reacts with PSMA found in the LNCaP cell line, but not DU-145 or PC3, which lack PSMA.

Suspected sodium toxicity in hand-reared great blue heron (Ardea herodias) chicks.

Sodium toxicity was suspected in hand-reared great blue heron (Ardea herodias) chicks fed herring frozen in brine (seawater). Affected chicks were lethargic with stiff legs that extended to the posterior, and breathing was labored. Chicks regurgitated food or refused to eat. All chicks that were fed herring exclusively and eight of the 10 chicks fed a mixed diet (herring and salmonids) died, whereas all chicks fed only salmonids survived. Renal lesions ranged from mild to marked generalized nephrosis, which was characterized by degeneration and necrosis of the proximal convoluted tubular epithelium and dilation of the distal convoluted tubules and collecting ducts. These observations suggest that fish frozen in brine is unsuitable food for hand-rearing of young herons.

Comparison of serum biochemical profiles of male broilers with female broilers and White Leghorn chickens.

Male broiler chickens were compared to female broiler chickens and male White Leghorns with respect to a 15-parameter serum biochemical profile at 9, 20, 30 and 42 days of age in order to determine which, if any, of the parameters tested might be useful in the identification of birds susceptible to sudden death syndrome. In comparison to female broilers, male broilers had significantly lower (p less than 0.01) total protein levels at 20 days of age and significantly higher (p less than 0.01) cholesterol levels at 30 days of age. Compared to male White Leghorns, in which sudden death syndrome has not been reported, male broilers had significantly lower (p less than 0.01) levels of cholesterol and creatinine at nine days of age, total protein at 9 and 20 days of age and albumin at 20 days of age and significantly higher (p less than 0.01) levels of potassium at nine days, uric acid at 9, 20 and 30 days, lactate dehydrogenase at 20, 30 and 42 days and cholesterol at 30 days of age.

Effect of feed restriction on feed efficiency and incidence of sudden death syndrome in broiler chickens.

An experiment was conducted to determine the effect of feed restriction on the incidence of sudden death syndrome (SDS). Body weight, feed efficiency, and incidence of SDS were compared for broilers fed ad libitum and broilers restricted in feed intake by 25%. Six pens of 50 male broilers were fed commercial-type texture diets ad libitum, and six pens of birds were restricted to 75% of this intake from 5 to 39 days of age. Growth rate and the incidence of SDS were significantly higher in ad libitum-fed broilers. Feed efficiency was better in the ad libitum-fed group up to 11 days of age and then became similar to that of the restricted group. Results support the hypothesis that the incidence of SDS is related to growth rate and suggest that SDS mortality may be reduced by growing broilers at a slower rate.

Organ weights of normal broiler chickens and those dying of sudden death syndrome.

Sudden death syndrome is an economically important condition of fast-growing broiler chickens in which death occurs suddenly with a short, wing-beating convulsion. Gross or histological lesions are not present. Relative weights of internal organs from broilers dead from sudden death syndrome were compared to those of normal broilers to determine differences that might confirm a diagnosis of sudden death syndrome. Relative weights of lung, heart, liver, and intestine from normal broilers were determined at 9, 21, 30 and 42 days of age at various intervals after death. Organ weights stabilized approximately two hours postmortem and relative organ weight declined with age. A diagnosis of sudden death syndrome could not be made on the basis of relative organ weight.