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Biomedical subjects

R H Wharton

Publications and source records attributed to R H Wharton.

At least 19 recordsLinked to original sources
PubMed1997

Acute idiopathic gastric dilation with gastric necrosis in individuals with Prader-Willi syndrome.

Individuals with Prader-Willi syndrome (PWS) have excessive appetite with the ability to consume large quantities of food. Absence of vomiting and a high pain threshold are considered manifestations of the disorder. We present 6 patients with PWS with acute dramatic gastric distention. In 3 young adult women with vomiting and apparent gastroenteritis, clinical course progressed rapidly to massive gastric dilatation with subsequent gastric necrosis. One individual died of overwhelming sepsis and disseminated intravascular coagulation. In 2 children, gastric dilatation resolved spontaneously. Gastrectomy specimens--in 2 cases subtotal and distal, in the other with accompanying partial duodenectomy and pancreatectomy--showed similar changes. All cases demonstrated signs of ischaemic gastroenteritis. All specimens showed diffuse mucosal infarction with multifocal transmural necrosis. Vascular dilatation and small bifrin thrombi were apparent within the infarcted areas. These 6 women with PWS had acute idiopathic gastric dilatation. It is possible that a predisposition to acute gastric dilatation may be related to abnormal gastric homeostasis on a genetic basis. Understanding the mechanisms responsible for this event could increase the understanding of gastrointestinal and appetite regulation in individuals with PWS.

Adult↗
PubMed1996

Genetic and clinical advances in Prader-Willi syndrome.

Prader-Willi syndrome is a developmental disorder with distinctive dysmorphic features, specific neurobehavioral attributes, and a characteristic learning profile. Advances continue to be made in understanding the factors associated with the loss of imprinted gene expression within chromosome 15q11-q13. These advances are helping providers make certain diagnoses early and are helping scientists uncover new genetic pathways. In addition, efforts to further understand the role of recombinant growth hormone therapy in Prader-Willi syndrome and the genetic information responsible for the neurobehavioral profile are additional targets for research.

Child, Preschool↗
PubMed1996

Advance care planning for children with special health care needs: a survey of parental attitudes.

OBJECTIVES: This study explored parental attitudes about their interactions with their children's providers when decision making involved critical life situations. We evaluated parents' attitudes regarding the following questions: What was the parents' understanding of their children's health care issues, and what was the parental perception of the professionals' understanding of their children and of themselves? Who should be the principal decision makers for the children? What was the parents' knowledge about advance directives? Did parents want to participate in a process of advance planning to assist with critical life decision making for their children? METHODS: We surveyed all parents attending a conference sponsored by the Massachusetts Department of Public Health for parents of children with special needs. The questionnaire was provided to all parents attending the conference. An announcement was made at the conference requesting parental participation. The 76 respondents constitute a convenience sample of parents of children with special needs sufficient for this preliminary stage of investigation. RESULTS: Of 177 parents attending the conference, 76 (43%) completed the questionnaire. Eighty-eight percent of the participants strongly agreed that they understood their children's conditions. Twenty-one percent stated that they had sufficient understanding of their children's future medical needs, and 21% thought that they had a sufficient understanding of their children's developmental potential. Ninety-nine percent of parents strongly agreed that physicians should share information with parents no matter how serious or potentially upsetting. Ninety-four percent of those parents who thought that their children's physicians understood their own needs also thought that the physicians understood their children's needs. In contrast, only half (55%) of those parents who thought the physicians did not understand their needs thought the physicians understood their children's needs. Ninety-two percent of parents who thought that the physicians understood their needs agreed that the physicians would make the best decisions in crises versus 60% of those who did not think the physicians understood their needs. Seventy-four percent stated that they would consider written guidelines for their children that dealt with critical life situations. All parents who thought their children's conditions were not understood wanted written guidelines. Of those parents who had thought their children would not survive (15 parents), 94% wanted written guidelines. All seven parents who had been told their children would not survive wanted written guidelines. CONCLUSIONS: Parents in this study were generally satisfied with care being provided to their children. Nevertheless, the results clearly suggest goals that could lead to improved capacity for parents and providers to make critical life decisions for and with children. First, physicians must understand the needs of parents to be able to make decisions that would be in the children's best interests. Second, parents should participate fully in critical life decisions for their children and should use written guidelines to assist with the process of these critical life decisions. Our findings strongly support the development of a longitudinal process, initiated early after the onset or discovery of illness and maintained longitudinally throughout the course of a child's illness, to help parents and providers work together in this vital area of health care to children.

Adult↗
PubMed1989

Neonatal respiratory depression and delay in diagnosis in Prader-Willi syndrome.

The authors retrospectively evaluated the diagnoses at four months of age for 48 individuals with known Prader-Willi syndrome. 15 had been diagnosed as having cerebral palsy, and at four months only two of the 48 had been correctly diagnosed as Prader-Willi syndrome. 11 (23 per cent) had had birth asphyxia, compared with an expected rate of 1 per cent. Other perinatal features which occurred more frequently than expected included breech presentation, decreased fetal movements and prolonged gestation. Failure to make an early diagnosis of Prader-Willi syndrome often results in later disability being blamed on the birth process, when instead the child's neonatal problems are secondary to a prenatal condition.

Adolescent↗
PubMed1982

Breeding for resistance to Boophilus microplus in Australian Illawarra Shorthorn and Brahman x Australian Illawarra Shorthorn cattle.

Breeding for resistance to the cattle tick Boophilus microplus was undertaken in a herd of Australian Illawarra Shorthorn (AIS) cattle from 1961 to 1978 and in a herd of Braham x AIS cattle from 1970 to 1979. Breeder cows and their progeny were assessed for tick resistance during October to January. Resistance levels were determined as the average percentage mortality of female ticks from two artificial infestations with cohorts of c 20,000 larvae. Resistance increased from 89.2% to 99% in the AIS breeding herd, as a result of the yearly introductions of more resistant individuals and culling of less resistant ones. Concurrently resistance in the AIS progeny increased from 93.7% to 97.7%, thus demonstrating that the selection and breeding of the cows and bulls resulted in genetic improvement in the resistance of the progeny. Milk production tests on heifers from the selected AIS herd during 1975 to 79 indicated that selection for tick resistance did not select against milk production. Resistance of the Brahman x AIS increased from 98.4% to 99.3% in the breeding herd and from 97.6% to 99.6% in the progeny. Female calves of both breeds were more resistant than males.

Animal Husbandry↗
PubMed1981

A survey for resistance in cattle ticks to acaricides.

A survey was made from late 1976 to late 1977 to determine the extent of resistance to acaricides in the cattle tick Boophilus microplus in Queensland. Questionnaires and requests for samples of ticks were forwarded to more than 900 randomly selected stock owners in the tick infested area which had been divided into 4 regions. Far North, Coastal North, Coastal Cental and South East. The response measured by the number of tick samples tested was 43%. The prevalence of resistance to organophosphorus (OP) compounds was highest in South East where 96% of the farms had OP-resistant ticks and 95% had the Biarra strain and lowest in Far North where 12% of the farms had OP-resistant ticks and 10% had the Biarra strain which was the predominant one in all regions. The highest percentages of the Ridgelands strain (35%) and the Tully strain (30%) occurred in Coastal North. The South East had the highest percentage of Mt Alford (30%). Although chlorinated hydrocarbons were banned for use in control of ticks in 1962, 49% of the farms in South East had some ticks resistant to dieldrin but in Far North it was only 2%. DDT-resistant ticks, which because of cross resistance to synthetic pyrethroids will affect the future use of this group, were present on 8% of the farms in both Coastal North and Coastal Central and 3% in South East and Far North. No resistance to the amidines, chlordimeform, chloromethiuron or amitraz was found.

Animals↗
PubMed1980

The effect of locality, breed and previous tick experience on seasonal changes in the resistance of cattle to Boophilus microplus (Ixodoidea: Ixodidae).

A seasonal cycle in the expression of resistance to the tick Boophilus microplus occurs in cattle in central and southeastern Queensland, Australia. This is due to a seasonal fluctuation in the capacity of cattle to mount an effective immune response against the parasitic tick and is manifest as a waning of the expression of resistance in autumn and early winter which occurs irrespective of breed or the nutritional state of the cattle.

Animals↗