Canine Demodicosis: A Re-examination of the Histopathologic Lesions and Description of the Immunophenotype of Infiltrating Cells.

Résumé- Cette étude décrit les modelités réactionnelles inflammatoires et l'immunophénotype des lésions histologiques de démodécie canine. Trois modalités principales sont décrites: une folliculite pariétale, une folliculite suppurative et furonculose, et une dermatite modulaire. La folliculite pariétale, réaction inflammatoire ciblée sur la paroi folliculaire, est présente dans tous les cas et constitue la modalité réactionnelle principale dans 17 cas sur 34 (50 pour cent). Le sous-type interface, caractérisé par une dégénérescence hydropique ou une apoptose des kératinocytes folliculaires, avec exocytose lymphocytaire, s'observe dans 15 de ces 17 cas. Une mélanose folliculaire et/ou une incontinence pigmentaire sont présentes sur 10 de ces 17 biopsies. Une dermatite nodulaire, représentée par un granulome périfolliculaire, est présente sur neur biopsies (26 pour cent). Une folliculite suppurative ou une furonculose est la modalité relationnelle dominante dans huit cas (24 pour cent). Tous les lymphocytes dans la paroi folliculaire sont des lymphocytes T CD3+, contre 10 pour cent sculement des cellules périfolluculaires. Les plasmocytes IgG+ constituent jusqu'à 74 pour cent des cellules périfolliculaires, et le pourcentage est encore plus élevé dans les cas de furonculose. Ces faits montrent que la folliculite pariétale est une lésion importante dans la démodécie canine, et suggère qu'une réaction à médiation cellulaire est dirigée spécifiquement contre la paroi folliculaire. [Canine demodicosis: a re-examination of the histopathologic lesions and description of the immunophenotype of infiltrating cells (La démodécie canine: réexamen des lésions histologiques et description de l'inmunophénotype des cellules infiltrantes). Resumen- Este estudio describe los patrones inflamatorios y el immunofenotipo de las lesiones histológicas en la demodicosis canina. Se identificaron tres patrones principales: foliculitis mural, foliculitis y furunculosis supurative, y dermatitis nodular. La foliculitis mural, una reacción inflatatoria dirigida a la pared folicular, se observó en todos los casos y constituia el patrón principal en 17 de los 34 casos (50%). En 15 de estos 17 casos la foliculitis mural era de tipo interfase, caracterizada por degeneración hidrópica o apoptosis de queratinocitos foliculares y exocitosis linfocitica. Se detectó melanosis folicular y/o incontinecia pigmentaria en 10 de estas 17 biopsias. Neuve biopsias (26 por ciento) presentaban dermatitis nodular, caracterizada por granulomas perifoliculares. Ocho casos (24 por ciento) mostraban foliculitis o furunculosis como patrón dominante. Linfocitos T CD3+ constituian la totalidad del infiltrado en la pared folicular, mientras que el mismo tipo celular representaban el 10 por ciento del infiltrado inflamatorio perifolicular. Hasta el 74 por ciento de las células perifoliculares eran células plasmáticas IgG+, con el mayor número en casos con furunculosis. Estos hallaz os indican que la foliculitis mural es una lesion importante la demodicosis canina y sugiere que una reacción mediada por células es dirigida a la pared folicular. [Canine demodicosis: a re-examination of the histopathological lesions and description of the immunophenotype of infiltrating cells (Demodicosis canina: repaso de las lesiones histopatológicas y descripción del inmunofenotipo del infiltrado celular). Abstract- This study describes the inflammatory patterns and immunophenotype of the histologic lesions of canine demodicosis. Three major patterns were identified: mural folliculitis, suppurative folliculitis and furunculosis and nodular dermatitis. Mural folliculitis, an inflammatory reaction targeting the follicular wall, was seen in all cases and was the principle pattern in 17 of 34 cases (50 per cent). The interface subtype of mural folliculitis, typified by hydropic degeneration or apoptosis of follicular keratinocytes and lymphocytic exocytosis, occurred in 15 of these 17 cases. Follicular melanosis and/or pigmentary incontinence occurred in 10 of these 17 biopsies. Nodular dermatitis, represented by perifollicular granulomas, was present in nine biopsies (26 per cent). Suppurative folliculitis or furunculosis was the dominant pattern in eight cases (24 per cent). All lymphocytes within the follicular wall were CD3+ T lymphocytes, compared to 10 per cent of the perifollicular cells. IgG+ plasma cells accounted for up to 74 per cent of perifollicular cells, highest in cases with furunculosis. These findings indicate that mural folliculitis is an important lesion of canine demodicosis, and suggests that a cell-mediated reaction is targeting the follicular wall.

Familial cutaneous vasculopathy of German shepherds: clinical, genetic and preliminary pathological and immunological studies.

A genodermatosis affecting the German shepherd breed has been recognized in 26 dogs in Ontario since 1991. Clinical signs, first noted in young puppies,are manifested as pyrexia and lethargy. The main cutaneous lesions are footpad swelling and depigmentation,but there is also crusting and ulceration of ear tips and tail tips, and focal depigmentation of the nasal planum. Affected puppies show no consistent abnormalities in hematological or biochemical parameters, and immunological tests (antinuclear antibody and rheumatoid factor titer,immunoglobulin levels, and CD4+ and CD8+T-lymphocyte percentages) are normal. Bone marrow analysis has shown myeloid hyperplasia in 5 of 7 cases and myelofibrosis has been detected in 1 case. All but 3 of the 19 clinical cases have been strongly positive for platelet factor-3; however, normal puppies routinely develop positive platelet factor-3 tests. Furthermore, affected pups all had normal numbers of platelets on repeat complete blood counts.Light microscopic examination of footpad biopsies reveals a multifocal nodular dermatitis in which neutrophils and mononuclear inflammatory cells surround foci of dermal collagenolysis, and degenerative and inflammatory vessel lesions. Depigmented lesions have a mild, cell-poor, interface dermatitis,characterized by single cell necrosis of the basal cells, in addition to the nodular dermatitis. Similarities and differences between this disease,a condition known as collagen disorder of the footpads of German shepherds and other forms of cutaneous vasculitis in the dog are discussed. The cause and the pathogenesis of the disease are yet to be elucidated;however, pedigree analysis indicates an autosomal recessive inheritance pattern. Hypersensitivity reactions, directed against normal or damaged self-collagen, may be involved. The role of cell-mediated immunity against native or altered collagen is an area worthy of further investigation.

Prophylactic oophorectomy in operable instances of carcinoma of the breast.

In 1964, a prospective study was initiated of prophylactic oophorectomy in operable instances of carcinoma of the breast, in patients who showed evidence of ovarian activity. Patients were randomized to a control group and a group treated by surgical castration. By December 1979, 359 patients were evaluable at five years and 240 patients at ten years. The over-all results of the oophorectomy series were superior to that for those of the control group. Patients who had cancer confined to the breast showed no significant benefit from oophorectomy. When one to three axillary nodes were involved, women less than 50 years of age were found to benefit significantly from prophylactic oophorectomy, in relapse-free status at five years, and in survival and relapse-free status at ten years. Patients 50 years of age and older showed no advantage from oophorectomy. It s suggested that there is a place for prophylactic oophorectomy in patients who are less than 50 years of age with operable carcinoma of the breast and with positive axillary nodes.

Allosomal and autosomal control of sex ratio in PHH and PHL mice.

When male mice from inbred PHH (sex ratio .535) and PHL (.435) are mated to females of various inbred lines, the sex ratio follows the male parent. The sex ratios from litters sired by reciprocal cross F1 males (letting A represent a set of autosomes) are 0.510 from AH/AL, XL/YH and 0.469 from AH/AL, XH/YL. The difference is statistically significant but only half the difference between pure strains. The paternal effect, presumably due to the Y, persists in progeny of the two kinds of F2 males. In backcrosses to the female parent, resulting finally in AH/AH, XH/YL and AL/AL, XL/YH, and in outcrosses, the effect of the Y chromosome does not persist, indicating that neither the Y alone, nor the autosomes alone, will cause the sex ratio to depart significantly from equality of sexes. When pairs of males in all possible combinations were presented with C57BL/6 females mating success gave the following ranking: AH-YL, AL-YL, AH-YH, AL-YH. The combination of autosomes from PHH and Y-chromosome from PHL seems to confer the greatest competitive advantage.