Dynamic respiratory endoscopy without treadmill in 68 performance Standardbred, Thoroughbred and saddle horses under natural training conditions.

Reasons For Performing Study: High speed treadmill endoscopy provides a true assessment and diagnosis of the dynamic obstructions of the upper equine respiratory tract (DO-URT). However, treadmills do not always allow reproduction of the exact conditions of dynamic collapse of the URT. The availability of on-board endoscopes, which could be used without a treadmill, would make exercising endoscopy readily available to more equine practices.

Immunolocalization of aromatase in stallion Leydig cells and seminiferous tubules.

High levels of plasma estrogens constitute an endocrine peculiarity of the adult stallion. This is mostly due to testicular cytochrome p450 aromatase, the only irreversible enzyme responsible for the bioconversion of androgens into estrogens. To identify more precisely the testicular aromatase synthesis sites in the stallion, testes from nine horses (2-5 years) were obtained during winter or spring.

Free and conjugated estrogens and androgens in stallion semen.

The steroid content of semen from a total of 11 mature fertile stallions was studied during two breeding seasons and one winter. The levels of free and conjugated substrates (testosterone and androstenedione), and products (estradiol and estrone), of aromatase were measured by radioimmunoassay with a validated method. The results were seasonally and monthly highly variable with characteristic peaks.

Aromatase gene expression in the stallion.

Adult stallion secretes very high estrogen levels in its testicular vein and semen, and the responsible enzyme cytochrome P450 aromatase (P450 arom) is known to be present mainly in Leydig cells. We studied in further details the distribution of equine aromatase in various adult tissues including the brain (hypothalamic area), liver, kidney, small intestine, muscle, bulbourethral gland and testes. The aromatase mRNA was essentially detected by RT-PCR in testis (169+/-14 amol of aromatase mRNA per microg of total RNA) and was barely detectable in brain, or below 0.

[Cervical lymph node inflammation in children].

One hundred and twenty seven cases of cervical lymph node infection were seen between 1974 and 1986 in children aged between 1 month and 10 years. The point of origin of the infection wa identified in 30% of cases and was, in decreasing order: cutaneous, in the cervico-cephalic region; pharyngo-tonsillar via the lymphatic structures of the pharynx or by direct effraction of the buccopharyngeal mucosa; and, finally, dental. The site of the secondary lymph node infection was generally below and behind the angle of the jaw and in some cases submandibular.