W. R. Klein

Local interleukin-2 therapy in bovine ocular squamous cell carcinoma. A pilot study.

SummaryFive cows bearing bovine ocular squamous cell carcinoma (BOSCC) were treated with low doses of recombinant human interleukin-2 (rhIL-2). A dose of 2500 U rhIL-2 was injected intralesionally and another 2500 U were injected into the subparotid regional lymph node once a day during a period of 5 consecutive days. This cycle of 5 days was repeated after an interval of 2 days. Total regression of the tumor was observed in three out of five animals. One cow showed tumor regression (> 80%) accompanied by metastases to the regional lymph node that were observed from the fifth week after the beginning of the treatment. Growth of the tumor of the fifth animal was retarded after treatment. In vitro proliferation of peripheral blood lymphocytes was investigated in two animals and tumor-infiltrating lymphocytes in one animal during incubation in various rhIL-2 concentrations. Cytotoxic activity of both cell populations against P815, Yac-1 and BOSCC-derived cell lines increased during incubation with rhIL-2. Cultured BOSCC-infiltrating lymphocytes showed predominant killing of the BOSCC-derived autologous cell line after 4 weeks of culture. Preliminary phenotype analysis did not give conclusive results with respect to the types of cells responsible for killing.

Urolithiasis in small ruminants. I. A retrospective evaluation of urethrostomy.

A retrospective study on the results of urethrostomy in 28 small ruminants was made. Ten animals were euthanised during surgery. In the 18 remaining animals short-term results were good. Recurrence of symptoms occurred in 8 animals (45%). Five animals were operated a second time, leading to 4 recurrences. Two animals were operated a third time and remained free of symptoms.

Three Cases of Carcinoid in the Equine Nasal Cavity and Maxillary Sinuses: Histologic and Immunohistochemical Features

Three cases of carcinoid tumor in horses are described. The tumors originated from the maxillary sinuses and the retrobulbar region and caused exophthalmos. Histologically, they had a characteristic endocrine pattern and were argyrophilic with the Grimelius stain. All tumors contained reactivity for neuron-specific enolase and synaptophysin. Two of three tumors were reactive for both bovine and porcine chromogranin A. These immunohistochemical results confirm the neuroendocrine nature of these tumors. Neuroendocrine cells could not be detected in the nasal mucosa and maxillary sinuses of a normal horse; therefore, the origin of these carcinoid tumors remains obscure.

Therapy of bovine ocular squamous-cell carcinoma with local doses of interleukin-2: 67% complete regressions after 20 months of follow-up

We have tested the therapeutic potency of peritumorally injected low doses of interleukin-2(IL-2). Seventy tumours of the bovine ocular squamous-cell carcinoma (BOSCC), 1–3 cm in diameter, were treated with 5000, 20 000 or 200 000 U IL-2 from Eurocetus (Chiron) to find the optimal dose for treatment. Injections were given peritumorally on Monday to Friday on 2 consecutive weeks. The size of the tumours was measured before treatment and 1, 3, 4, 9 and 20 months after treatment. After 9 months complete regression was observed in 89% of the tumours treated with 5000 U IL-2, 80% treated with 20 000 U and 67% treated with 200 000 U. After 20 months, there was complete regression of 35%, 31% and 67% of the tumours respectively. The 9-and 20-month results of the 200 000-U treatment are significantly better than those of the 5000-U and 20 000-U treatments taken together. This protocol may be useful to treat advanced inoperable tumours (e.g. of the nasopharynx or skin) of human patients.

Endotoxin, interleukin-6 and tumor necrosis factor concentrations in equine acute abdominal disease: relation to clinical outcome

Serial peri-operative plasma and serum samples from 55 horses suffering from acute abdominal disease and presented for surgical intervention were assayed for the presence of endotoxins (lipopolysaccharides; LPS), tumor necrosis factor (TNF) and interleukin-6 (IL-6). At study entry, venous blood was collected for blood cultures. Intra-operatively collected ascitic fluid samples were assayed for the presence of LPS. The clinical course of the disease was documented. Four horses were excluded from the study. At study entry, 21 of the 51 horses (41%) had increased platelet-rich plasma LPS concentrations, i.e. ≥ 5 ng/l (mean 35.5; range 7-197 ng/l), in 34 horses (67%) IL-6 concentrations were increased, i.e. exceeding 35 ng/l (mean 364; range 36—1762 ng/l). Detectable TNF was present in 5 horses (10%); 3 of them died spontaneously during surgery. In all TNF positive samples, markedly increased LPS and IL-6 concentrations were detected. Study entry IL-6 concentrations were significantly higher in non-surviving (mean 394; range < 20—1762 ng/l) than in surviving horses (mean 116; range < 20—894 ng/l; P < 0.0002). This was most evident when non-surviving horses with inflamed bowel disease were considered (mean 1096; range 650—1762 ng/l; P < 0.0001). Positive ascitic fluid LPS concentrations (≥ 3 ng/l) were encountered in 18 horses. There was no significant correlation between the LPS concentrations in ascites and plasma. Study entry concentrations of IL-6 were significantly correlated with LPS concentrations (r = 0.62; P < 0.001) and were inversely correlated with platelet counts (r = -0.46; P < 0.002). The magnitude of a calculated LPS-cytokine score strongly correlated with mortality (P < 0.001). Receiver operating characteristic (ROC) curve analysis showed that the IL-6 assay had reasonable accuracy for the prediction of unfavorable outcome (i.e. the area under the curve equalled 0.72), in contrast to the LPS assay. The results indicate that LPS, TNF and IL-6 are predominantly released in the systemic circulation of horses suffering from inflamed and ischemic bowel disease. IL-6 concentrations have predictive value for unfavorable outcome and the simultaneous presence of increased LPS, TNF and IL-6 concentrations is especially associated with a poor clinical condition and outcome.

Laboratory and clinical evaluation of a chromogenic endotoxin assay for horses with acute intestinal disorders

Summary In this study the laboratory and clinical performance of a chromogenic endotoxin assay for equine plasma was evaluated. The assay was sensitive (detection limit 3 ng LPS/L plasma), reproducible (within and between-assay CV at 50 ng LPS/L E.coli 0111:B4 LPS standard addition was 5% and 7.5%, respectively), and not substantially affected by enhancement or inhibition phenomena (recovery of an in vitro spike was 75-125% in 80% of the samples). LPS added to whole blood was rapidly inactivated upon incubation at 37 °C but not at 0 °C. A recently developed blood collection tube for LPS testing was found suitable, i.e. LPS-free and providing non-contaminated samples. In 48 horses suffering from acute abdominal diseases requiring surgical treatment, LPS levels were significantly higher in platelet-rich plasma (PRP) than in platelet-poor plasma (PPP), and the proportional difference was related to the PRP platelet count (r=0.52, p<0.001, mean difference 48%, range 8-77%). LPS levels were also significantly higher in horses that died or were euthanized than in surviving horses (mean 16.5 and 7.1 ng/L PRP, respectively, p<0.05). We conclude that LPS can be measured in equine plasma with picogram sensitivity and recommend the use of PRP instead of PPP for clinical LPS testing. For clinical use a decision limit for endotoxaemia of 5 ng LPS/L PRP appeared to be inadequate. Analysis at a higher cut-off level for endotoxaemia and the evaluation of clinical, pathological, and laboratory parameters would be more meaningful.

Side effects of oral antimicrobial agents in the horse: a comparison of pivampicillin and trimethoprim/sulphadiazine

To evaluate the side effects of oral pivampicillin and trimethoprim/ sulphadiazine, 200 horses receiving these antimicrobial agents were studied. The horses received either trimethoprim/ sulphadiazine (30 mg/kg twice daily) or pivampicillin (25 mg/kg twice daily) for three or more days. No adverse effects other than loose faeces and diarrhoea were detected. The risk of diarrhoea was significantly less after the oral administration of pivampicillin (3 per cent) than after trimethoprim/ sulphadiazine (7 per cent). Horses whose appetite was reduced appeared to be predisposed to develop diarrhoea after the administration of either oral antimicrobial agent.

Optimal regimes for local IL‐2 tumour therapy

In this report we present studies on optimal regimes for regional IL‐2 therapy, focused on dose, schedule and site of injection. Original data obtained in 2 murine tumour models show that all 3 factors are of importance. Anti‐tumour responses were most effective when IL‐2 was administered regionally 5 to 10 times, at doses ranging from 7,000 to 33,000 IU/day every day or every other day. This resulted in cure rates of more than 40% in mice bearing ascitic tumour that had also disseminated to liver and lungs. The importance of these data is discussed in the light of previous results of our group. These results illustrate that the doses and schedules used in this study are not effective exclusively in these 2 tumour models but may have a more general applicability. ©1996 Wiley‐Liss, Inc.

The effects of cisapride on the restoration of gut motility after surgery of the small intestine in horses; A clinical trial

Seventy horses surgically treated for colic caused by disorders of the small intestine were included in a randomized blind trial to determine the effects of cisapride (0.1 mg/kg bw intramuscularly at 8-h intervals) on the post-operative restoration of gut motility. Cisapride appeared to reduce the incidence of post-operative ileus. It accelerated the restoration of bowel motility, reducing the period of post-operative intensive care. It is concluded that cisapride is an effective and useful drug in the post-operative treatment of horses after surgery of the small intestine.

A modified technique for implantation of polypropylene mesh for the repair of external abdominal hernias in horses: A review of 21 cases

During a 3-year period 21 horses were surgically treated because of large abdominal wall defects. In each case the defect was bridged with a polypropylene mesh, which was placed on the outside of the hernial ring. This was in contrast with the technique for mesh herniorrhaphy generally described in human and veterinary literature, in which the mesh is always implanted on the inside of the hernial ring. One horse was destroyed on the first postoperative day because of postanaesthetic myelomalacia. Surgical repair as described was successful in 18 patients. Recurrence of herniation occurred in two horses. On re-herniorrhaphy a second and larger mesh was successfully implanted.