The Pekin duck IL-10R2 common chain: cDNA cloning, genomic structure, molecular characterization and mRNA expression analysis

The interleukin-10 receptor 2 (IL-10R2, IL-10Rβ) is required for the signalling of the class 2 cytokines IL-10, IL-22, IL-26 and IFN-λ1-3 . Here, we describe the identification of the Pekin duck IL-10R2 (duIL-10R2) common chain and its gene structure. The duIL-10R2 cDNA encodes a 343 amino acid protein that has an amino acid identity of 76% and 42% with chicken and human IL-10R2, respectively. Binding residues of human IL-10R2 for IL-10 and IL-22 were mostly conserved in the avian IL-10R2 proteins within loops L3 and L5, but not within loops L2 and L6. Homology modelling of the duIL-10R2 extracellular domain structure using soluble human IL-10R2 (shIL-10R2, PDB ID: 3LQM) as a template revealed a protruding loop L5 and two distinct clefts between loops L2/L3 and L3/L5, similar to shIL-10R2. However, in contrast to the three amino acid β-hairpin loop L2 of shIL-10R2, loop L2 of duIL-10R2 is five residues longer. Residues within a putative Tyk2 binding site were highly conserved across all vertebrate IL-10R2 proteins examined. The duIL-10R2 gene shares a seven exon-six intron structure with chicken and human IL-10R2 genes, but avian genes are more compact. DuIL-10R2 mRNA was constitutively expressed in all tissues. Mitogen stimulation of duck peripheral blood mononuclear cells (PBMC) did not alter transcript levels. Our observations suggest that genomic organization and structural features implicated in multiple cytokine-binding properties of human IL-10R2 are conserved in duck IL-10R2, but the evolutionary changes that appear to have lead to low-affinity cytokine interaction within loop L2 are distinct to mammalian species.

[Establishment of the Cancer Registry]

In 1948, the WHO proposed that five countries, Norway among them, should study the incidence of cancer. Three years later the Norwegian Ministry of Health and Social Affairs issued instructions for the reporting of all cases of cancer to the new Cancer Registry of Norway. Its first director was Dr. Einar Pedersen, who was succeeded by Dr. Frøydis Langmark in 1983. Between 1957-61 and 1992-96, the number of cancer cases increased from 41,648 to 99,601. Most types of cancer were up; stomach cancer was an exception to this trend. The increase was highest for malignant melanoma and lung cancer, for both types higher among women than among men. There are considerable variations in cancer incidence between Norwegian counties, between the municipalities within the counties, and between urban and rural communities.

[Registration of canine cancer]

A Norwegian Canine Cancer Registry, covering four of 19 counties, has been operative since March 1990. Until the end of April 1994 about 6,000 tumours have been registered, more than 50% of these being manifestly or potentially malignant. Among 14 selected breeds the relative risk ratio for all tumours varies with factor 35 from boxer to dunker, the boxer having the highest tumour risk. The percentage distribution of specified tumour types also varies greatly between breeds, mammary cancer constituting 59% of all neoplasms in the dachshund, but only 4% in the Bernese mountain dog. Because of the genetic diversity between breeds the dog is a suitable species for differentiation between genetically determined predisposition and environmental influences in the etiology of cancer. Epidemiological surveillance of cancer morbidity in dogs may be a useful instrument for tracing carcinogens, even in the surroundings of man.

A model for car exhaust exposure calculations to investigate health effects of air pollution

This paper presents a model for car exhaust exposure calculations, which improves the air pollution exposure estimates necessary to study relationships between health and air pollution. The model enables calculation of hour-by-hour air pollution concentrations at receptor points in an area. Combined with a diary method, in which participants in the study give data on their movement in the area, the model enables personal air pollution exposure values to be calculated. The paper shows examples of comparison between measured and calculated exposure.

Oxalate nephropathy in a Tibetan spaniel litter. A probable case of primary hyperoxaluria

Severe oxalate nephropathy with end-stage kidney lesions was found in two pups of a litter of three Tibetan Spaniels. This histopathological finding strongly suggests a primary hyperoxaluria since there was no exposure to agents capable of producing secondary hyperoxaluria. Primary hyperoxaluria has not been reported as a spontaneous disease in the dog, although it is a well-known, but rare, inherited metabolic disease of man.

Plasmacytoma of the uvea in a case of multiple myeloma

A case of plasmacytoma in the uvea, both clinically and grossly anatomically mimicking a malignant melanoma, is described in a 63-year-old man who died from multiple myeloma. This is an extremely rare condition in the eye. Only one report of a similar tumour has been found in the literature.

Liver cell necrosis and regeneration following injections of carbon tetrachloride. Effects of the thyrotropin-releasing hormone and somatostatin

Mice were given 10 micrograms somatostatin or 25 micrograms TRH intraperitoneally 10 min before s.c. injection of 2 or 20 mg CCl4. The extent of liver cell necrosis and nuclear size were measured by the electronic Mini Mop method and the extent of necrosis and nuclear pleomorphism were estimated by a visual linear analogue scale of 100 mm, and compared to plasma concentrations of ASAT and ALAT. Pre-treatment with TRH or somatostatin resulted in significant reduction in the extent of necrosis 24 h after CCl4-injections (25%), with a lowering of ASAT from 13209 +/- 2955 U/l to 5144 +/- 924 after TRH and to 6186 +/- 966 after somatostatin, and of ALAT from 14343 +/- 3209 to 7718 +/- 1727 and 6494 +/- 1253 U/l, respectively. After 3 days the necroses were reduced from 16.5 +/- 1.7% by the Minimop method to 1.4 +/- 0.5% (90%) in mice given CCl4 alone, and from 12.3 +/- 1.7% to 3.8 +/- 1.2% in mice pretreated with TRH, and from 12.3 +/- 1.8% to 3.8 +/- 1.7% (70%) in mice pretreated with somatostatin. The plasma concentrations of ASAT and ALAT were reduced correspondingly. After 5 days no necroses were seen, and the plasma ASAT and ALAT were normal. After 6 months of weekly injections of TRH or somatostatin before 20 mg CCl4 the liver cell nuclear size (10.5 and 9.7 0.3 mu 2) was similar to that after CCl4 alone (9.7 0.3 mu 2), and twice that of controls (4.6-5.4 0.1 mu 2). Liver cell necrosis was not seen. The plasma concentrations of ASAT (131 8.6-162 11.3) and ALAT (98 8-104 9 Iu/l) were similarly 2-3 times those in controls. TRH and somatostatin thus reduced liver cell injury and delayed regeneration after single injections of CCl4. After 6 months of weekly injections no effects were observed.

The morphology of human cells from the choroid and retinal pigment epithelium grown in vitro on isolated Bruch's membrane

Cells from samples of human choroidal tissue were collected and seeded onto isolated Bruch's membrane in vitro, and the morphology of the developing cultures was examined by light-, scanning electron- and transmission electron-microscopy. In early cultures, the cells showed a flattened, spread out appearance with short surface villi and a low degree of cellular overlapping. After 48 h, a shift towards a more elongated cell form was observed, and one week old cultures were composed of predominantly elongated cells with a pronounced degree of overlapping. In contrast, human retinal pigment epithelial cells seeded onto sheets of Bruch's membrane maintained a spread out epithelial morphology with a varying degree of overlapping throughout the culture period. The present system permits comparative studies on the behavior of choroidal and pigment epithelial cells under controlled conditions. It may serve as an in vitro model for disorders characterized by growth of these cells on Bruch's membrane in vivo.

Prostaglandins and CCl4-induced liver cell mortality. The effect of the prostaglandin analogue enprostil

Prostaglandins have been reported to reduce the carbon tetrachloride (CCl4)-induced liver cell injury in rats. The object of the present experiments was to examine the effect of the prostaglandin E2 analogue enprostil on the survival of isolated liver cells exposed to CCl4. Liver parenchymal cells were isolated from rat livers by collagenase perfusion and released into a 'suspension' buffer. Aliquots of the cell suspension were incubated with 1 micrograms or 0.5 microgram CCl4, and to parallel test suspensions 20 ng enprostil was added 5-10 min before CCl4. Incubation was performed on ice, at room temperature, and at 37 degrees C. The average percentage of dead cells after CCl4 treatment was significantly reduced by pretreatment with enprostil at room temperature (1 microgram CCl4: 69 +/- 21% and 44 +/- 13%, respectively) and after 10 min of incubation at 37 degrees C (1 microgram Cl4: 56 +/- 25% and 37 +/- 27%; 0.5 microgram CCl4: 51 +/- 33% and 29 +/- 18%, respectively). When the liver cell mortality approximated 100% after long-term incubation at 37 degrees C, no protective effect of enprostil was observed.

Human retinal pigment epithelium in long term explant culture

Explants of human retinal pigment epithelium were maintained in culture in various types of media, and examined by light and transmission electron microscopy. After one month in vitro, the central areas showed a monolayered configuration with distinct polarity and presence of ruthenium red stainable material on the apical surface. On the peripheral areas of Bruch's membrane, multilayered lesions were observed to develop and to extend from the monolayered epithelium and past the cut edge in Bruch's membrane. Cells in these lesions contained little melanin and generally lacked an apico-basal polarity. Ruthenium red staining revealed the presence of electron dense material on the apical surface of the lesions as well as in the extracellular space between cells in the various layers. Development of multilayered lesions with deposition of extracellular material are seen in various chorio-retinal disorders, including senile macular degenerations and also subsequent to laser and cryo-therapy. The findings in the present study point to the explant culture system as a valuable tool in the study of important aspects of chorio-retinal pathology.

The neural crest origin of uveal melanomas

On the basis of two cases the relation between 'neurogenic' tumours (neurinomas, neurilemmomas, Schwannomas, neurofibromas) and malignant melanomas of the uvea is discussed with emphasis on the close association of both groups of neoplasms with the ciliary nerves. The great histopathological diversity between different cases of melanoma as well as within individual cases is also pointed out. On histological and cytological criteria it may be difficult to differentiate between the 'neurogenic' tumours and the highly differentiated, spindle cell variants of the melanomas. Since all these tumours are derived from the neural crest, they might be grouped under one common heading. It is postulated that 'neurogenic' tumours have been overdiagnosed to the disadvantage of the highly differentiated spindle cell melanomas.

Congenital blindness with ocular developmental anomalies, including retinal dysplasia, in Doberman Pinscher dogs

Hereditary, congenital blindness was studied in 15 Doberman Pinscher pups. The eyes were smaller than normal, and there was complete absence of the anterior chamber, aphakia, retinal detachment, and dysplasia as well as an irregular swelling and partial depigmentation of the retinal pigment epithelial cells. It was concluded that the condition was inherited as a recessive, autosomal trait.

The emergence of antigenic variants is a rare event in long-term visna virus infection in vivo

Six sheep persistently infected with visna virus were studied for 4 1/2 to 5 3/4 years until they became ill. Virus was isolated at intervals from peripheral blood leukocytes and cerebrospinal fluid (CSF), and at the time of sacrifice from various parts of the brain and the lungs. Both brain and lungs showed lesions typical of advanced visna/maedi. All the sheep formed antibodies in sera and CSF. Virus isolates from each sheep were tested in neutralization tests against sera and CSF collected from the same animal. In one sheep all isolates were found to be identical to the inoculated virus by this test. In each of the other sheep an antigenic variant emerged from 1 to 3 years after inoculation and remained in circulation even after the formation of autologous antibodies. In one case a variant was isolated from the lungs, whereas in all cases the virus isolated from the brain was identical to the inoculated virus. The results show that antigenic variants are rare in visna and do not seem to have a role in the pathogenesis of the disease.

Surface morphology of explants from the human retinal pigment epithelium in culture. A scanning electron microscopic study

The alterations in surface morphology in human retinal pigment epithelium in explant culture was studied by scanning electron microscopy. After 14 days in culture, large areas of the epithelium showed well preserved surface villi. In some zones, however, the density of the finger-like villi were reduced and the shorter villi became more visible. The short villi are lamellar in structure and constitute systems of communicating membranous folds and not isolated structures as previously believed. Most of the tall finger-like villi were found to have their bases on the top of these folds. Dead cells followed 2 different pathways of degeneration. Some showed large ruptures in the membrane, followed by expulsion of organelles and finally detachment of the cell from Bruch's membrane. With other cells, a progressive disintegration of the cell membrane was observed. The first type of degeneration occurred most frequently in dilated, single cells, whereas the latter type was found in larger areas of necrosis.

Monolayered explants in the study of retinal pigment epithelial behavior in culture

A technique that permits removal of viable retinal pigment epithelial (RPE) explants of determined size from Bruch's membrane, and the transfer of such explants with maintained apico-basal polarity to cell culture dishes is presented. The RPE is a polarized tissue where the apical surface is involved in the interchange of material between the choroid and sensory retina and in phagocytosis of visual receptor outer segments. The maintenance of this polarity is of importance in studies aimed at elucidating these functions on pure RPE explants in early primary culture. No previous work has presented a method that permits this maintenance. The possibility of standardizing the size of these explants should facilitate quantitative studies on phagocytosis and uptake of markers and labelled compounds. The described dissection procedure is also currently used to separate the RPE as a pure cell population from surgically removed chorio-retinal biopsies for cell culture purpose.

Reactive changes in the human retinal pigment epithelium in vitro

Explants from the retinal pigment epithelium and the underlying choroid and sclera were dissected from human eyes and transferred to culture wells. The mechanical trauma caused by the dissection and removal of the explants, and the changes in biological milieu caused by transfer of the tissue to an in vitro system causes injury, necrosis and detachment of cells from Bruch's membrane. In the retinal pigment epithelium, cells adjacent to damaged, spherical and detaching cells and smaller cell free zones from rosettes. At the periphery of big defects, the cells spread out to cover the denuded areas of Bruch's membrane. The present work has shown that cell injury in the human retinal pigment epithelium is followed by reactive cellular changes in vitro. The result of these reactive changes are increased variation in cellular form and magnitude and in pigment concentration per unit area.

Ocular encephalitozoonosis (nosematosis) in blue foxes. Polyarteritis nodosa and cataract

In young blue foxes an association has previously been established between the protozoon Encephalitozoon (Nosema) cuniculi and generalized arterial lesions of the polyarteritis nodosa type. The same vascular changes are found in the posterior ciliary arteries and their intraocular branches of these foxes. Most of the eyes which are thus affected, have a severe cataract. The parasite can easily be demonstrated both in the arteries and the lenses. It is thought that the Encephalitozoon is the cause of the vascular lesions and the cataract, and that possibly an autoimmune reaction is involved.

Encephalitis in ferrets caused by a nonproductive strain of measles virus (D.R.) isolated from patient with subacute sclerosing panencephalitis

A nonproductive, syncytiogenic strain (D.R.) of measles virus, isolated from a patient with subacute sclerosing panencephalitis (SSPE), was inoculated intracerebrally into ferrets in an attempt to induce subacute encephalitis. Inoculation of freeze-thawed syncytia before immunization was the least effective procedure, and inoculation of live syncytia after immunization with measles virus vaccine was the most effective procedure, for induction of subacute or persistent subclinical encephalitis in the animals. After the latter procedure three of five ferrets developed subacute or subclinical encephalitis, whereas ferrets inoculated with live syncytia without prior immunization consistently contracted acute fatal encephalitis in one to two weeks. The subacute encephalitis in ferrets was characterized by high titers of antibody to measles virus in serum. At the time of sacrifice 1.25, 4.5, or 8.0 months after inoculation, brains of the ferrets showed histologic lesions similar to those characteristic of SSPE, and nonproductive syncytiogenic measles virus was recovered from the brains of two of the animals. All three ferrets had greatly increased concentrations of gamma-globulin in their brains and high levels of neutralizing and hemagglutination-inhibiting antibodies to measles virus. Only one of these animals developed clinical signs 1.25 months after inoculation.

Orbitography with a new non-ionizing water-soluble contrast medium

Metrizamide is a non-ionic water-soluble contrast medium which is isotonic with human blood and tissue fluid at a concentration of 170 mgI/ml. Retrobulbar injection of 3 ml isotonic metrizamide in the muscular conus of rabbits causes slight and inconstant cellulitis, but a similar reaction can also be found after injection of the same amount of saline. It seems probable that the introduction of fluid sufficient to cause an increase in the retrobulbar pressure can cause inflammatory changes in the orbital tissue, and that this is not always caused by the contrast medium itself. Four patients were examined by orbitography with injection of 4 ml isotonic metrizamide. There were no side effects, and the orbitograms showed contrast of good quality. Metrizamide is therefore considered very suitable for orbitography, especially in hospitals where computer-tomography is not yet available.

Malignant melanoma of the choroid as related to coexistent benign nevus

Ninety-five cases of malignant choroidal melanoma collected during a 15-year period have been studied with special emphasis on histological type, coexistence of benign nevus, and prognosis. Elements of benign nevus were found in 78% of the cases. The data tend to support the hyposis that most cases of malignant choroidal melanoma have their origin in a preexisting benign nevus, and that the tumours undergo a gradual change from a differentiated to a less differentiated type.