Mosaic RAS/MAPK variants cause sporadic vascular malformations which respond to targeted therapy.

Background: Sporadic vascular malformations (VMs) are complex congenital anomalies of blood vessels that lead to stroke, life-threatening bleeds, disfigurement, overgrowth, and/or pain. Therapeutic options are severely limited, and multidisciplinary management remains challenging, particularly for high-flow arteriovenous malformations (AVM).

Methods: To investigate the pathogenesis of sporadic intracranial and extracranial VMs in 160 children in which known genetic causes had been excluded, we sequenced DNA from affected tissue and optimized analysis for detection of low mutant allele frequency.

Suppression of behavioural and physiological oestrus in the mare by vaccination against GnRH.

Objective: To examine the immunogenicity of an equine immunocontraceptive vaccine and its efficacy in controlling hormone-related behaviour.

Design: A total of 24 mares at two sites in Australia were vaccinated with an immunocontraceptive vaccine comprising gonadotrophin releasing hormone (GnRH) conjugated to a carrier protein in immunostimulating complex as an adjuvant. Twelve animals at each site received a placebo of adjuvant alone and served as controls for seasonal oestrus, hormonal and behaviour patterns.

Unusual ovarian activity in a mare preceding the development of an ovarian granulosa cell tumour.

An 8-year-old mare, with a foal at foot, was inseminated on foal heat with frozen semen, with the resultant pregnancy lost between days 34 and 41. The right ovary developed a large anovulatory follicle that was non-responsive to multiple doses of ovulating agents. The follicle eventually appeared to luteinise, although plasma progesterone concentrations did not reflect this.

Preliminary study of ovarian activity in fillies treated with a GnRH vaccine.

Objective: To investigate the effects of two doses (200 and 400 mg) of a water-soluble gonadotrophin-releasing hormone vaccine on the ovarian activity of 2-year-old fillies.

Design: A controlled vaccination dose rate experiment.

Animals: Six 2-year-old Australian Stock Horse fillies were randomly allocated to three treatment groups; unvaccinated controls, those receiving 200 mg of the vaccine and those receiving 400 mg of the vaccine.

Automated chemoenzymatic synthesis of no-carrier-added [carbonyl-11C]propionyl L-carnitine for pharmacokinetic studies.

Propionyl-L-carnitine (PLC) is under development as a therapeutic for the treatment of peripheral artery disease, coronary heart disease and chronic heart failure. Three methods were examined for labelling PLC in its propionyl group with positron-emitting carbon-11 (t12 = 20.3 min), one chemical and two chemoenzymatic.

Suppression of testicular function using two dose rates of a reversible water soluble gonadotrophin releasing hormone (GnRH) vaccine in colts.

Objective: To investigate the effect of two dose rates (200 and 400 ng) of a gonadotrophin releasing hormone (GnRH) vaccine on testicular function.

Design: A vaccination dose rate experiment.

Procedure: Two injections were administered 4 weeks apart to six colts in each treatment group.

Utilization of endogenous and dietary urea in the large intestine of the mature horse.

The dynamics of N metabolism in mature horses were investigated when they were fed on a low-N diet or the same diet supplemented with sufficient urea or soybean meal to meet their theoretical N requirements. There were no differences in DM, organic matter or neutral-detergent-fibre digestibilities for the three diets. N digestibilities and digestible-N intakes were similar for the urea- and soyabean-supplemented diets and very low for the low-N diet.

The influence of age and breed on stallion semen.

This study reports on the variation in semen quality and in spermatozoal and behavioral characteristics of 168 stallions representing 9 breeds and ranging in age from 2 to 26 yr. Semen samples were collected into an artificial vagina and the number of mounts and urethral pulsations per semen sample were recorded. Semen characteristics were examined for total volume, gel-free volume, gel volume, color score, mass activity, nonmotile spermatozoa, dead spermatozoa, semen density, spermatozoa concentration, total number of spermatozoa and semen pH.

Immunocastration of colts and immunospeying of fillies.

A series of experiments using an ovalbumin conjugated gonadotrophin releasing hormone was used to stimulate antibody production, suppress testosterone secretion and depress testicular function in yearling and 2 year old colts and fillies. In the preliminary experiment, an injectable oil-based formulation was administered to yearling colts. Testicular development and testosterone secretion were retarded for a period of approximately 28-32 weeks while antibody titres were greater than 1:1000.

Seasonal variation in the estrous cycle of mares in the subtropics.

Data on the estrous cycles and sexual receptivity scores of 7 maiden Australian Stock Horse mares were used to study seasonal variation from December until the following November. Mares were grazed in paddocks containing both native and improved tropical pasture species. The study was conducted in South-East Queensland (27 degrees 27' South latitude).

Milk and water intakes of foals sucking grazing mares.

Intakes of milk and milk nutrients were determined for 8 foals at 11-18 days of age and for 10 foals at 30-44 days and 60-74 days of age while sucking grazing mares. Water intakes (sources other than milk) of the foals were determined at 30-44 days and 60-74 days of age. Five of the 10 mares were fed a protein supplement (24% crude protein) in addition to grazing during the stud season.

Effect of lupin (Lupinus angustifolius) supplementation on ovarian and pituitary activity in ewes.

In each of three experiments, thirty seasonally anoestrous Border Leicester ewes were fed on a maintenance ration of oaten chaff. Fifteen of them were given a supplement of 500 g lupin grain per head per day. The ewes were treated with 10 mg follicle stimulating hormone (Expt 1), 600 I.

Effects of a protein deficient diet and urea supplementation on lactating mares.

Six lactating mares were fed either a low protein diet or the same diet with added urea ad libitum over 71 days. The quantity consumed by the mares, milk intakes of their foals, milk composition, plasma urea nitrogen (PUN), mare liveweight changes and foal growth rates were measured. The mares were unable to consume sufficient quantities of either diet to meet their nitrogen requirements and all lost weight.

Ovarian activity in fillies treated with anabolic steroids prior to the onset of puberty.

This study investigated the effects of zero, low (0.55), medium (1.1) and high (2.

A preliminary study of immunological castration in colts.

This study tested the effectiveness of a conjugated GnRH vaccine for stimulating antibody production, suppressing testosterone secretion and depressing testicular development in yearling colts. Two colts were allocated to each of three groups, (1) control, (2) subcutaneous and (3) intramuscular vaccinations. Two injections of the vaccine were given 11 weeks apart.

A study of nonsurgical embryo transfer in the mare.

The success rate of nonsurgical embryo recovery was influenced neither by year nor by season within years. The preferred method of nonsurgical embryo transfer was by Cassou pistolette. From a total of 15 attempts to transfer embryos nonsurgically, 9 (60%) were successful.

Synthesis and absorption of cysteine from the hindgut of the horse.

The extent to which cysteine synthesised by microbes within the hindgut of the horse is incorporated into plasma cysteine was estimated by an isotopic technique in two horses fed four different diets. The results showed that between 1 per cent and 6 per cent of the plasma cysteine was of microbial origin. It is argued that the maximum contribution of microbial cysteine, and presumably other amino acids of microbial origin, to the plasma pool is 12 per cent of the net supply.

Morphological characteristics of stallion spermatozoa.

A study of the morphological characteristics of stallion spermatozoa was conducted at the semen laboratory of the Department of Animal Production during four breeding seasons. A total of 590 ejaculates collected from 216 stallions aged from 2 to 26 years and including 13 breeds or colour types was examined. Overall means for the spermatozoal characteristics of these stallions and the classes of head and tail abnormalities are presented and compared with results of other works.

Seasonal and circadian changes of testosterone levels in the peripheral blood plasma of stallions and their relation to semen quality.

Three stallions were bled each hour for 25 h at 28-day intervals throughout 1 year. Testosterone levels were pulsatile. Pulse frequency and pulse amplitude were higher in the summer months than at other times (P less than 0.

The repeatability of seminal characteristics of stallions.

Fifteen seminal characteristics were measured in ejaculates from 4 laboratory stallions and from 164 commercial stud stallions. Complete field and laboratory data were available from 536 and 531 ejaculates, respectively. These were obtained over 4 breeding seasons (1974/75-1977/78) and 9 breeds were represented.

Characteristics and fertility of stallion semen.

A study of stallion fertility was conducted on commercial studs in eastern Australia over 4 breeding seasons (1974/75-1977/78). Data from 47 stallions (66 stallion seasons) aged 2-26 years and representing 7 breeds and 1664 mares were used to relate seminal characteristics to fertility. Percentage pregnancies per service was the most sensitive measure of fertility with stallions on commercial studs.

Collection of semen from stallions at stud.

Semen was collected from 222 stallions of 13 breed or colour types in southern Queensland and northern New South Wales. A total of 648 collection attempts were made, using an artificial vagina, during 4 consecutive breeding seasons (1974/5 to 1977/8). Modifications were made to the techniques used by previous workers because collections were made at commercial studs using minimal animal restraint.