Leukocyte differentiation antigens in canine cutaneous and oral plasmacytomas

Seventeen cutaneous and oral tumours with light microscopic features of plasmacytomas from 16 dogs were studied. Clinically, most neoplasms were benign, although three recurred after excision and three were locally invasive. Tumours most often arose on the pinnae, digits, gingiva, and inguinal regions near areas of chronic inflammation and exhibited variable degrees of plasmacytic differentiation microscopically. Diagnosis of plasmacytoma was confirmed in paraffin-embedded tissues with a panel of leukocyte differentiation antigen markers that included cross-reactive antibodies for Mb-1 (CD79a), CD3, and vimentin and canine-specific antibodies for CD45RA and CD18. Immunoreactivity for Mb-1 and CD45RA, including staining of multinucleate cells and cells with karyomegaly, confirmed a B-cell origin of neoplasms, while staining for CD3 and CD18 revealed an extensive network of infiltrative T-cells and dendritic cells in tumours suggestive of a directed immune response. These findings (i) demonstrate the value of using a panel of antibodies for leukocyte antigens to differentiate plasmacytomas from other cutaneous and oral round cell tumours, and (ii) suggest that immune recognition and responsiveness within tumours may play a role in the behaviour of plasmacytomas in dogs by affecting tumour cell growth and differentiation.     

Dystrophic (Dermolytic) Epidermolysis Bullosa in a Cat

Abstract— Dystrophic epidermolysis bullosa was diagnosed in an 8-month-old male domestic shorthaired cat. Lesions noted were paronychia, ulcers on the palate, oropharynx, gums and tongue, as well as ulceration and crusts on the metacarpal, metatarsal and digital pads. Histology of lesions showed dermal-epidermaj separation and ulceration. Immunohistochemistry showed collagen IV (characteristic of the lamina densa) located at the roof of the cleft at both the dermal-epidermal and follicular-dermal interfaces. Electron microscopy showed the dermal-epidermal cleft to be sublamina densa. Résumé— Une épidermolyse bulleuse dystrophíque a été diagnostiquée chez un chat européen à poils courts de huit mois. Les lésions étaient une paronychie, des ulcères du palai, de l'oropharynx, des gencives et de la langue ains que des ulcères et des croutes au niveau des métacarpes, métatarses et coussinets plantaires. L'examen histologique des lésions faiasait apparaitre des ulcérations et des disjonctions derme/épiderme. L'étude immunohistochimique a montré la présence de fibres de collagène IV (caractéristiques de la lamina densa) sur lew toit des bulles tant au niveau des interfaces derme/épiderme que derme/follicule. La microscopie électronique a montré que les séparations derme/épiderme se faisaient au niveau de la sublamina densa. Zusammenfassung— Eine dystrophe Epidermolysis bullosa wurde bei einer achtjährigen kurzhaarigen männlichen hauskatze diagnostiziert. Die beschriebenen Veränderungen bestanden in Paronychie, Ulzera an Gaumen, Oropharynx, Gingiva und Zunge sowie Ulzerationen und Krusten an den metacarpalen, metatarsalen und digitalen Ballen. Die Histologie der Veränderungen zeigte dermal-epidermale Trennungen und Ulzerationen. Mit der Immunhistochemie wurde Kollagen IV nachgewiesen (ein Kennzeichen der Lamina densa), das am Gewölbe der Spaltbildung sowohl an den derma-epidermalen als auch an den follikulär-dermalen Schnittstellen lokalisiert war. Die Elektronenmikroskopie zeigte, daß die dermal-epidermale Spaltbildung die Sublamina densa darstellte. Resumen En un gato macho de ocho meses doméstico de pelo corto se diagnóstico epidermolisis distrófica bullosa. Las lesiones presentes fueron paroniquia, úlceras del paladar, orofaringe, encías y lengua, así como ulceraciones y costras en las regiones del metacarpo, metatarso, y almohadillas plantares. Las lesiones histologicas consistieron de separación y ulceración a nivel de la dermis y epidermis. Exámenes inmunohistoquímicos demostraron la presencia de colágeno IV (característico de la lámina densa), localizado en el techo de las indentactiones en ambas interfases, epidermo-dérmica y foliculo-dérmica. Por medio de microscopía electrónica se comprobo que las indentaciones de la dermis y epidermis consistían de sublámina densa.     

Epidemiology and Clinical Features of Dermatophytosis in Dogs and Cats at Louisiana State University: 1981–1990

Abstract— Dermatophytes were cultured from seventy of 1824 (3.8 per cent) canine samples and 61 of 408 (14.9 per cent) feline samples submitted over ten years. Microsporum canis was the most common species isolated (86/131). M. gypseum (31/70) and M. canis (30/70) were isolated most frequently from dogs whereas M. canis was isolated most frequently from cats (56/61). Both male and female dogs and cats were equally affected by dermatophytosis. There was a higher incidence in both dogs and cats less than one year of age. Mixed breed dogs (19/70), domestic shorthaired cats (39/61) and Persian cats (15/61) were most often affected. M. gypseum had a greater incidence of infection in summer and most often caused localized disease in dogs. In dogs, localized dermatophytosis was more common. Localized infections were most often caused by M. canis in all animals, with the head (23/75), feet (10/75) and tail (7/75) affected most frequently. Résumé— Dos dermatophytes ont été isolés à partir de 70/1824 (3,8 pourcent) prélèvements canins et 61/408 (14,9 pourcent) prélèvements félins collectés sur une période de dix ans. L'espèce la plus souvent isolée était Microsporum canis (86/131). Microspomm gypseum (31/70) et M. canis (30/70) étainet les plus fréquemment isolés chez les chiens, alors qu'il s'agissait de M. canis (56/61) chez les chats. Les mâles et les femelles, chiens ou chats, étaient également représentés. Il y avait une nette incidence des animaux de moins d'un an, tant chez les chiens que chez les chats. Les chiens croisés (19/70), les chats européens (39/61) et les chats Persans (15/61) étaient les plus souvent atteints. L'incidence de M. gypseumétait plus importante l'été et provoquait les plus souvent des lésions localisées les chiens. Les formes localisées étaient plus fréquentes chez les chiens et le plus souvent dues àM. canis dans les deux espèces, avec une atteinte préférentielle de la tête (23/75), des membres (10/75) et de la queue (7/75). Zausammenfassung— Aus siebzig von 1824 Proben von Hunden (3,8 Prozent) und 61 von 408 Proben von Katzen (14,9 Prozent) von einem Zeitraum über zehn Jahre wurden Dermatophyten angezüchtet. Microsporum canis war die am häufigsten isolierte Spezies (86/131). Microsporum gypseum (31/70) und M. canis (30/70) wurden am häufigsten bei Hunden isoliert, M. canis dagegen wurde am häufigsten bei Katzen isoliert (56/61). Männliche wie weibliche Hunde und Katzen waren gleichermaßen von Dermatomykosen betroffen. Sowohl bei Hunden also auch bei Katzen war die Inzidenz bei Tieren unter einem Jahr höher. Am häufigsten erkrankten Mischlingshunde (19/70), Kurzhaarhauskatzen (39/61) und Perserkatzen (15/61). Die Inzidenz der Infektion mit M. gypseum war im Sommer größer, bei Hunden verursachte es mehr lokalisierte Erkrankungen. Bei Hunden überhaupt waren lokalisierte Dermatomykosen häufiger anzutreffen. Lokalisierte Infektionen wurden bei alien Tieren am häufigsten durch M. canis verursacht, am meisten betroffen waren Kopf (23/75), Pfoten (10/75) und Schwanz (7/75). Resumen Se cultivaron dermatofitos de setenta de 1824 (3,8 por ciento) muestras caninas y 61 de 408 (14,9 cor ciento) muestras felinas, sometidas durante diez anos. Microsporum canis fue la mas común de las especies aisladas (86/131). Microsporum gypseum (31/70) y M. canis (30/70) se aislaron mas frecuentemente de perros, mientras que M. canis fue aislado con más frecuencia de gatos (56/61). Ambos, macho y hembra, perros y gatos fueron igualmente afectados por la dermatofítosis. Había una mayor incidencia en perros y gatos menores de un año de edad. Perros de cruce de razas (19/70), gatos domésticados de pelo corto (39/61) y gatos persas (15/61) fueron afectados con más frecuencia. M. gypseum tenía una mayor incidencia de infección en verano, y muy frecuentemente causaba enfermedades localizados en perros. En perros, fue más commún la dermatofitosis localizada. Infecciones localizadas eran más frecuentemente causadas por M. canis en todos los animates, con la cabeza (23/75), pies (10/75) y rabo (7/75) afectados con más frecuencia.     

从菠萝薄细胞层切片直接诱导体细胞胚

 以菠萝(Ananas comosus L. Merrill) 杂交种MD1 无菌苗为材料, 通过培养薄细胞层切片 (Thin cell layer, TCL) 的方法, 研究直接再生胚的固体培养体系。结果证明, 预培养的设计2 (在预培养基PT上黑暗预培养无菌苗1周后, 从预培养苗茎顶端切取TCL, 在MS + 2, 4-D 2 mg·L ^{- 1}或1 mg·L ^{- 1}胚诱导培养基EI2上黑暗培养1周, 然后转到光照条件下继续诱导胚1周, 再在成熟胚培养基EM上培养2周, 最后转入幼苗培养基PL上培养) 是直接诱导获得体胚的最佳途径; 诱导的体胚最初均来自于薄细胞层上微管束附近的细胞; picloram有利于芽的诱导, 2, 4-D有利于直接再生胚, 但如果球形胚形成后一直培养在较高浓度的2, 4-D培养基中, 将阻碍球形胚和心形胚进一步发育为成熟胚, 反而促进芽的生成。     

The Impact of Environmental Regulations on the Industry Structure of Landfills

ABSTRACT Over the past twenty years, the environmental regulation of landfills has become increasingly restrictive both at the federal and state levels. Using a panel dataset of Ohio landfills, we developed a theoretical framework to explain the landfill operators’ responses to regulatory actions, and then estimate an empirical model of changes in industry structure. Because not all Ohio counties have landfill operations, we hypothesize that there is self‐selection in the location of landfills, which is accounted for with an appropriate econometric model. The study finds that environmental regulations had significant impact both on the location of landfill operations and concentration of the industry during the time period studied.     

The Accuracy of Intraoperative Diagnoses Based on Examination of Frozen Sections A Prospective Comparison with Paraffin-Embedded Sections

The accuracy of diagnoses based on examination of frozen sections was determined by comparing the results to those obtained by examination of tissues prepared using conventional methods (formalin fixation, paraffin-embedded tissue). One hundred ninety-four specimens were examined using the frozen section technique; 37 were examined to confirm a tentative diagnosis or to document lymph node metastasis and the remainder were examined to diagnose an unknown pathologic process. Of the 194 specimens examined, an accurate, specific diagnosis was obtained in 161 (83%); in 19 (10%), the pathologic process was correctly identified, but a specific diagnosis was not obtained; and in 2 (1%) the diagnosis was deferred. The remaining 12 (6%) were incorrectly diagnosed by the frozen section technique. When the number of specimens in which a specific diagnosis was obtained was combined with the number of specimens in which the pathologic process was correctly identified, the overall accuracy rate of the frozen section technique was 93%. There was no difference in the accuracy of the frozen section technique based on the reason for submission of the sample, source of tissue submitted, or the type of pathologic process (i.e., inflammatory or neoplastic). Of the 12 incorrect diagnoses, 4 (33%) were because of sampling errors and 8 (67%) were caused by interpretation errors. The proposed indications for the use of intraoperative frozen sections are: 1) to determine the nature of a pathologic process for which a preoperative diagnosis has not been established, 2) to determine the extent of spread of neoplastic tissue to lymph nodes and other organs, 3) to evaluate resection margins of a neoplastic process, and 4) to clarify situations where a discrepancy exists between the preoperative cytologic or histologic diagnosis and intraoperative gross pathology.     

Blood Gas Values During Intermittent Positive Pressure Ventilation and Spontaneous Ventilation in 160 Anesthetized Horses Positioned in Lateral or Dorsal Recumbency

One hundred sixty horses were anesthetized with xylazine, guaifenesin, thiamylal, and halothane for elective soft tissue and orthopedic procedures. Horses were randomly assigned to one of four groups. Group 1 (n = 40): Horses positioned in lateral (LR_G1,; n = 20) or dorsal (DR_G1,; n = 20) recumbency breathed spontaneously throughout anesthesia. Group 2 (n = 40): Intermittent positive pressure ventilation (IPPV) was instituted throughout anesthesia in horses positioned in lateral (LR_G2; n = 20) or dorsal (DR_G2; n = 20) recumbency. Group 3 (n = 40): Horses positioned in lateral (LR_G3; n = 20) or dorsal (DR_G3; n = 20) recumbency breathed spontaneously for the first half of anesthesia and intermittent positive pressure ventilation was instituted for the second half of anesthesia. Group 4 (n = 40): Intermittent positive pressure ventilation was instituted for the first half of anesthesia in horses positioned in lateral (LR_G4; n = 20) or dorsal (DR_G4; n = 20) recumbency. Spontaneous ventilation (SV) occured for the second half of anesthesia. The mean time of anesthesia was not significantly different within or between groups. The mean time of SV and IPPV was not significantly different in groups 3 and 4. Variables analyzed included pH, PaCO₂, PaO₂, and P(A-a)O₂ (calculated). Spontaneous ventilation resulted in significantly higher PaCO₂ and P(A-a)O₂ values and significantly lower PaO₂ values in LR_G1, and DR_G1, horses compared with LR_G2 and DR_G2 horses. Intermittent positive pressure ventilation resulted in normocarbia and significantly lower P(A-a)O₂ values in LR_G2 and DR_G2 horses. In LR_G2 the Pao₂ values significantly increased from 20 minutes after induction to the end of anesthesia. The PaO₂ and P(A-a)O₂ values were not significantly different from the beginning of anesthesia after IPPV in DR_G2 or DR_G3. The PaO₂ values significantly decreased and the P(A-a)O₂ values significantly increased after return to SV in horses in LR_G4, and DR_G4. The PaO₂ values were lowest and the P(A-a)O₂ values were highest in all horses positioned in dorsal recumbency compared with lateral recumbency and in SV horses compared with IPPV horses. The pH changes paralleled the changes in PaCO₂. Blood gas values during right versus left lateral recumbency in all groups were also evaluated. The PaO₂ values were significantly lower and the P(A-a)O₂ values were significantly higher during SV in horses positioned in left lateral (LR_LG1) compared with right lateral (LR_RG1) recumbency. No other significant changes were found comparing left and right lateral recumbency. Arterial hypoxemia (PaO₂ < 60 mm Hg) developed in 35% of DR_G1 horses and 20% of DR_G2 horses at the end of anesthesia. Arterial hypercarbia (PaCO₂= 50–60 mm Hg) developed in DRoi horses. Arterial hypoxemia that developed in 20% of DR_G3 horses was not improved with IPPV. Arterial hypoxemia developed in 55% of DR_G4 horses after return to SV. Some DR_G4 horses with hypoxemia also developed hypercarbia, whereas some had PaCO₂ values within normal limits. Arterial hypoxemia developed in one LR_G1, and two LR_G4, horses. Hypercarbia developed in onlv one LR_G4 horse.     

Aetiology of an ulcerative disease in goldfish, Carassius auratus (L.): characterization of the causative agent

Abstract. A bacterium resembling Aeromonas salmonicida and determined to be the aetiologic agent of a cutaneous ulcerative disease in goldfish Carassius auratus (L.) was further characterized in this study.
Forty-five isolates of the bacterium (43 from the United States and one each position (moles % guanine plus cytosine) and DNA homology. The bacteriological atypical A. salmonicida previously described. Several important biochemical characteristics distinguished the goldfish isolates from typical A. salmanicida , but the DNA binding experiments indicated a high degree of relatedness between the goldfish isolates and typical A. salmonicida strains.