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Biomedical subjects

A W Roberts

Publications and source records attributed to A W Roberts.

At least 19 recordsLinked to original sources

Hemolytic uremic syndrome/thrombotic thrombocytopenic purpura: outcome with plasma exchange.

A retrospective analysis was made of 14 consecutive adults with hemolytic uremic syndrome/thrombotic thrombocytopenic purpura (HUS/TTP) who were treated with plasma exchange (PE). In six patients the disease was primary, whilst in eight HUS/TTP was considered secondary to an associated condition. Thirteen patients had renal involvement, six had central nervous system symptoms or signs, three had fever, and one had myocardial damage. Twelve patients (86%) recovered. Four of these relapsed, but responded to further treatment. Two patients failed to respond and died. Hematological response occurred rapidly in survivors: thrombocytopenia resolved after a median of four exchanges, and hemolysis after a median of six. Four patients had a complete recovery, seven had residual mild end organ damage, and one had severe renal impairment. PE was an effective treatment for both primary and secondary HUS/TTP. The platelet count proved to be the earliest indicator of clinical outcome. Continuing follow-up of survivors is required because of the risk of relapse and the high incidence of end organ damage.

Adolescent

Attempted transmission of Ehrlichia risticii (Rickettsiaceae) with Stomoxys calcitrans (Diptera: Muscidae).

Experimental transmission of Ehrlichia risticii, the causal agent of Potomac horse fever, was attempted with adult stable flies, Stomoxys calcitrans, (L.) using two feeding schedules. In schedule A, a set of 140 flies was allowed to feed once on an experimentally infected donor pony and once 24 h later on a recipient pony. A different set of flies was used each day for a 12-d period. In schedule B, 240 flies were allowed to feed once daily for 12 consecutive d on the donor pony followed by five consecutive daily feedings on the recipient pony. E. risticii was isolated from the blood of the experimentally infected pony during the entire fly-feeding schedule. The recipient pony did not develop clinical signs of Potomac horse fever and remained seronegative to E. risticii up to 60 d after the last stable fly feeding. Mice injected intraperitoneally with emulsions of schedule A and B stable flies were seronegative for E. risticii 30 d after inoculation, and ehrlichial organisms were not demonstrated in impression smears from the digestive tracts of the flies. The stable fly did not transmit E. risticii under these experimental conditions.

Animals

Status of equine viral arteritis in Kentucky, 1985.

Clinical cases of equine arteritis virus infection have not been diagnosed in Kentucky since 1984, and there has been no indication that any of the horses involved in the 1984 epizootic have since been responsible for spread of the disease to horses in other states or other countries. Cases of abortion caused by naturally acquired infection with this virus have not been confirmed in 1984 or 1985. Neither field nor vaccine strains of equine arteritis virus have been shown to induce teratologic abnormalities or the carrier state in foals born to infected or vaccinated mares. The carrier stallion appears to have played a major epidemiologic role in the dissemination and perpetuation of the virus. A commercial modified live equine viral arteritis vaccine was found to be safe and efficacious for stallions and mares. The disease can be controlled by immunizing the stallion population and by restricting the breeding of equine arteritis virus-shedding stallions to vaccinated or seropositive mares, followed by an appropriate period of isolation from other nonvaccinated Equidae.

Animals

The carrier state in equine arteritis virus infection in the stallion with specific emphasis on the venereal mode of virus transmission.

The carrier state has been confirmed virologically in Thoroughbred and non-Thoroughbred stallions naturally infected with equine arteritis virus (EAV). Short-term or convalescent and long-term carriers occur. The frequency rate of the long-term carrier state in Thoroughbreds was high, averaging 33.9% among the three groups of stallions under study. While the convalescent carrier state only lasted a few weeks after clinical recovery, the long-term carrier state could persist for years. There was evidence, however, that not all such carriers might remain persistently infected for life. Carrier stallions appeared to shed EAV constantly in the semen but not in the respiratory secretions or urine. It also could not be demonstrated in the buffy coat of the blood. All of the carrier stallions have continued to maintain moderate to high neutralizing antibody titres to EAV in serum. Virus was associated with the sperm-rich and not the pre-sperm fraction of semen. There was relatively little variation in virus concentration between sequential ejaculates from the same stallion. Transmission of EAV infection by long-term carrier stallions would appear to occur solely by the venereal route. Such carriers are thought to play an important epidemiological role in the dissemination and perpetuation of the virus.

Animals

Demonstration of the carrier state in naturally acquired equine arteritis virus infection in the stallion.

The chronic carrier state was virologically confirmed in 15 thoroughbred stallions naturally infected with equine arteritis virus based on the results of test matings and, or, isolations of the virus from semen. Carrier stallions were shown to shed equine arteritis virus in the semen for at least one to two years. Existence of a short-term or convalescent carrier state was also demonstrated in five additional stallions. The frequency of the long-term carrier state in stallions naturally infected with equine arteritis virus was 35 per cent; it varied considerably between groups of stallions on different farms. The carrier stallion would appear to play an important epidemiological role in the dissemination and perpetuation of equine arteritis virus.

Animals

Invasive carcinoma of the cervix in young women.

The cases of 194 women aged 40 years of age or less who had been diagnosed as having invasive cervical cancer in Queensland during 1972-1981 were reviewed retrospectively. Medical records contained a previous cervical cytological report for 89 women, with 18 of these having had a negative result of a smear test within two years of the diagnosis of invasive cancer. Cytological review of five of the 18 cases revealed neoplastic cells in three cases, and possible sampling inadequacies in the other two. Gynaecological symptoms had been present in seven of the 18 patients at the time of the negative result of cytological examination, and these persisted until the diagnosis was eventually made. A high index of suspicion is required when symptoms persist in spite of negative results of cytological examination and we recommend a review of the smear, a repeat smear examination with adequate sampling and referral for colposcopic examination in these circumstances.

Adult

Comprehensive self-medication program for epileptic patients.

The establishment and operation of a comprehensive self-medication program for hospitalized epileptic patients are described. The patients in the program are required to meet established behavioral criteria during each of four stages of self-medication before progressing to the next stage. The patient has increasing responsibility in each successive phase of the program. The areas of patient involvement for the pharmacist are: (1) obtaining a medication history, (2) teaching patients about seizure medications, (3) conducting patient consultations during the self-medication program and (4) counseling the patient at discharge.

Counseling