G. De Vico

Nuclear morphometry in relation to lymph node status in canine mammary carcinomas

The assessment of nuclear area and nuclear shape by morphometric analysis, has been investigated in 40 canine mammary carcinomas in relation to their metastatic behaviour to regional lymph-nodes. The tumours were reviewed by two experienced pathologists blinded regarding their lymph-node status, and were classified according to the histogenetically based criteria suggested by Benjamin et al. (1999). Twenty of these tumours showed lymph-node metastases (node-positive), and the other twenty were node-negative. Node-positive tumours included 6 simple adenocarcinomas, 10 ductular carcinomas, 2 anaplastic carcinomas and 2 carcinomas in mixed tumours; node-negative tumours included 18 adenocarcinomas %96, 10 simple adenocarcinomas, 8 complex adenocarcinomas %96, and 2 carcinomas in mixed tumours. Node-positive tumours showed MNA and mean SDA values significantly higher (p<0.001) than node-negative carcinomas. Data of this study, seems to confirm the importance of an histogenetically based classification in canine mammary tumours, also suggesting that morphometry may increase our prognostic performances allowing a reproducible method for detecting individual tumours with higher metastatic potential.

Diprosopiasis in a lamb. A case report.

Conjoined twinning has been reported in most of the domestic animal species. Among them, sheep have the highest incidence of craniofacial defects. A live male crossbreed dystocic two‐headed lamb was delivered from a 2‐year‐old Pinzerita sheep after first mating. After 40 h of life, the lamb spontaneously died. The most important gross findings involved the head, whereas the examination of different organ and tissue sections did not reveal remarkable histomorphological changes. The lamb was classified as a conjoined twinning and, on the basis of the facial duplication, as a diprosopus tetraophtalmus.

301 NEW APPROACHES TO CONTRACEPTION IN DOGS USING GnRH ANALOGUES, CALCIUM, AND NALOXONE

The continuous administration of GnRH leads to the desensitization and down-regulation of GnRH receptors on pituitary gonadotropes (Parker and Schimmer 2001 in Goodman & Gilmans The Pharmacological Basis of Therapeutics, New York: McGraw-Hill, 1541–1562). In this study, we combined the use of a GnRH analogue with calcium/naloxone association (Sciorsci et al. 2000 Immunopharmacol. Immunotoxicol. 22, 575−626) to obtain a desensitizing effect on LH receptors in an attempt to regulate spermatogenesis in dogs. Eight post-pubertal mixed breed dogs were divided into two groups: (A) four subjects were pharmacologically treated with a 30 day administration of buserelin acetate (Suprefact Aventis Pharma, Italy) 0.3 mg/each s.c. TID, associated with 0.1-mL/kg/bw i.m. injection SID of calcium gluconate 20p (New ICC, Upjohn, Italy) in which 0.4 mg/mL of naloxone hydrochloride (Diosynth, The Netherlands) was dissolved; (B) four subjects received placebo (NaCl 0.9p s.c. TID for 30 days). At the end of the treatment, hemiorchidectomy was performed and 4 months later the second testis was removed. Clinical examination of the genital tract was done by ultrasound monitoring. Before and after pharmacological treatment and until total orchidectomy, semen was collected and evaluated for macroscopic and microscopic parameters. Plasma testosterone concentration was measured twice a week by RIA. Testicular specimens were fixed in formalin solution, embedded in paraffin wax and stained with hematoxylin–eosin. The presence of germ cells and the testicular tubule diameters were analyzed using a computer assisted image analyzer (MONO system, Italy). Data were analyzed by the ANOVA test. In the treated group, all dogs showed a reduction in testicular and prostatic diameters compared to the control group. Transient elevations in testosterone concentrations were observed in response to the early injections and reached baseline levels after 8–10 days. The testosterone decline resulted in lower ejaculate volume and, at the end of treatment, azoospermia was observed. At the end of treatment, testosterone values had progressively regained normal values over 2 months and, when measured immediately before total orchidectomy, sperm concentration and motility had returned to normal. At the histological observation, seminiferous tubules showed the block of spermatogenesis at the level of spermatocytes with a statistically significant cell reduction in spermatides and spermatozoa (P < 0.001) whereas the seminiferous tubular morphometry was normal. Total orchidectomy demonstrated that a normal histological testicular structure had been restored. In the control group, no modifications were observed. As observed in a previous study (Aiudi et al. 2005 Reprod. Fert. Dev. 17(2), 280–281), GnRH induced suppression of the reproductive function in male dogs. In this study, we demonstrated that GnRH analogue associated with calcium and naloxone induces the same effect in a shorter time and that this effect is reversible. These devices designed for the shutdown of gonadal steroidogenesis and spermatogenesis would be useful for treating sex hormone-dependent syndromes such as malignant and benign prostatic tumors.