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Biomedical subjects

G Ford

Publications and source records attributed to G Ford.

At least 55 records · Page 3Linked to original sources
PubMed1991

Survivors of extreme prematurity--outcome at 8 years of age.

Of 149 infants liveborn in a large maternity hospital in 1980 to 1982 and delivered between 24 and 29 completed weeks of gestation inclusive, 91 (61%) survived; 88 (97%) survivors were assessed at 8 years' corrected age; 77% of children were not disabled; disability was mild in 13%, moderate in 2% and severe in 4% of children. Although survival decreased with decreasing gestation, disability in survivors did not increase. An earlier assessment of the same children at approximately 2 years of age had been unduly pessimistic particularly for those born less than or equal to 26 weeks' gestation. The only other reports in the literature on outcome by gestation have all assessed the children in early childhood, and estimates of severe disability rates from these studies will probably also be too pessimistic. Since the rate of severe disabilities in infants of borderline viability is not much higher than in more mature infants the obstetrician should mainly consider survival chances for the fetus, and not be overly concerned with long-term neurological outcome, when making clinical decisions.

Australia↗
PubMed1990

Types and correlates of blood/injury-related vasovagal syncope.

This study investigated by interview, the initial syncopal episode of 103 blood/injury-related vasovagal fainters in order to examine two competing hypotheses concerning their origins. Graham (Circulation, 23, 901-906, 1961) postulated that the faint resulted when sympathetic nervous system (SNS) activity ceased on termination of a threat, leaving parasympathetic nervous system (PNS) activation unopposed. Engel [Fainting (2nd edn), 1962; Annals of Internal Medicine, 89, 901-906, 1978] proposed that when in the face of threat with SNS activation, escape is blocked, the PNS becomes activated as the conservation-withdrawal response, leading to syncope. We found cases clearly conforming to each of these formulations as well as some with characteristics of both, and some who fainted in response to blood or injury but with no perception of threat. The Graham and Engel types did not differ in terms of fear or avoidance of blood, injury, or medically-related situations nor did they differ in the frequency with which their parents reported blood/injury-related syncopal episodes. It is proposed that both may be activated by a common psychological mechanism involving cessation of a defensive posture. In contrast, the non-threat fainters showed significantly less medically-related avoidance and had a greater percentage (94%) of parents with positive faint histories.

Adult↗
PubMed1990

Persistent infection of rhesus macaques with a molecular clone of human immunodeficiency virus type 2: evidence of minimal genetic drift and low pathogenetic effects.

In an attempt to generate a suitable animal model to study the infectivity and possible pathogenicity of human immunodeficiency viruses, we intravenously inoculated juvenile rhesus macaques and African green monkeys with a molecularly cloned virus, human immunodeficiency virus type 2 HIV-2sbl/isy, as well as with the uncloned HIV-2nih-z virus. Infection was monitored by virus recovery from the peripheral blood cells and by seroconversion against HIV-2 antigens measured by Western immunoblot, radioimmunoprecipitation, and enzyme-linked immunosorbent assay. We successfully infected two out of two macaques with the molecularly cloned virus and one macaque out of two with the HIV-2nih-z. No evidence of infection was seen in the African green monkeys with either virus. We followed the infected animals for 2 years. The animals remained healthy, although we observed intermittent lymphadenopathy and a transient decrease in the absolute number of circulating CD4+ T lymphocytes in both animals infected with the molecularly cloned virus. Virus isolation from the peripheral blood cells of the infected animals was successful only within the first few months after inoculation. Evidence of persistent infection was provided by the detection of proviral DNA by polymerase chain reaction analysis of the blood cells of the inoculated animals and by the stability of antiviral antibody titers. To evaluate the genetic drift of the proviral DNA, we molecularly cloned viruses which were reisolated 1 and 5 months postinoculation from one of these animals. Comparison of the DNA sequences of the envelope genes of both these isolates indicated that a low degree of variation (0.2%) in the envelope protein had occurred in vivo during the 5-month period. These data suggest that the use of HIV-2sbl/isy in rhesus macaques may represent a good animal model system to study prevention of viral infection. In particular, molecularly cloned virus can be manipulated for functional studies of viral genes in the pathogenesis of acquired immune deficiency syndrome and provides a reproducible source of virus for vaccine studies.

Animals↗
PubMed1989

The metabolism and testicular toxicity of cyclohexylamine in rats and mice during chronic dietary administration.

Cyclohexylamine hydrochloride has been given in the diet to mice and to Wistar and DA rats for 13 weeks, to provide a constant intake of 400 mg of the base/kg/day. Significantly decreased food intake and body weight gain were found in both strains of rats but not mice. The metabolism of [14C]cyclohexylamine was widely different in Wistar and DA rats and in rats and mice, and these differences were not altered appreciably by chronic intake for 13 weeks. The differences in metabolism resulted in marked and persistent differences in the concentrations of the hydroxylated metabolites in the plasma and testes of treated animals with Wistar much greater than DA much greater than mice. After 7 and 13 weeks testicular atrophy was demonstrated in both strains of rats given cyclohexylamine diet by a decrease in organ weight and by histological changes. DA rats appeared more sensitive to testicular toxicity from cyclohexylamine than Wistar rats, while mice showed no evidence of testicular damage. These data show that the development of testicular toxicity is not related to the extent of hydroxylation. The concentrations of cyclohexylamine in the plasma and testes of the treated animals were lower in mice than in either strain of rats despite a similar daily intake. This suggests that species differences in pharmacokinetics may contribute to the apparent difference in sensitivity to testicular toxicity.

Animals↗
PubMed1989

Reduction of fractured nasal bones; local versus general anaesthesia.

This prospective study was designed to asses whether the results of reducing simple fractures of the nasal bones were different using local or general anaesthesia. Two consecutive groups of 50 patients had their fractures manipulated under (a) general, or (b) local anaesthesia. The results of reduction as assessed by the patients and surgeons were not significantly different between the 2 groups. The reoperation rate for nasal obstruction and external deformity was similar in the 2 groups. We suggest that fractured nasal bones may be reduced under local anaesthesia without detriment to the results. This represents a significant saving of hospital resources.

Adolescent↗
PubMed1989

Magnetic resonance imaging of pituitary and parasellar abnormalities.

The ease, safety, accuracy, reliability, specificity, and sensitivity of the diagnosis of disorders of the sellar region all have been enhanced by MRI. This article demonstrates the normal anatomy and the wide array of pathology that can be visualized by MRI. Magnetic resonance has become the imaging modality of choice for most of the disorders within and about the sella.

Adenoma↗
PubMed1987

Outcome in infants of birth weight 500 to 999 g: a continuing regional study of 5-year-old survivors.

During 1979 and 1980, 351 infants of birth weight 500 to 999 g were born in the State of Victoria: 89 (25.4%) survived to the age of 2 years corrected for prematurity, and 83 were fully assessed by a multidisciplinary team; partial data were obtained on the remainder. At the age of 5 years, corrected for prematurity, 85/89 (96%) were evaluated by a multidisciplinary team, although not all children could be fully evaluated by the psychologists. Reports were available for another three children; one child was untraced. Of the survivors able to be classified at 5 years, 59/82 (72%) had no functional handicap. Functional handicaps was severe in 16 (19%), moderate in four (5%), and mild in three (4%). Functional handicaps were present in 50% (8/16) of outborn survivors compared with the 23% (15/66) for the inborn survivors (P = 0.02). Cerebral palsy was diagnosed in eight children at 5 years and in 12 children at 2 years. The diagnosis was stable for the children not ambulant at 2 years; five of seven 2-year-old children with mild cerebral palsy had "outgrown" the diagnosis by 5 years, but ataxic cerebral palsy was not identified in one child until 5 years. Six children were blind; four had severe sensorineural or mixed deafness, one more than at 2 years. Of 82 children assessed according to identical criteria for functional handicap at both 2 and 5 years, 52 (63%) remained in the same category at 5 years, three (4%) were judged to be more severely handicapped, and 27 (33%) were less severely handicapped. The 2-year evaluation of extremely low birth weight children often proved to be unduly pessimistic, for many showed improvement or recovery from functional handicaps and impairments by 5 years of age.

Australia↗
PubMed1986

Relationship of growth and psychoneurologic status of 2-year-old children of birthweight 500-999 g.

There were 257 liveborn infants of birthweight 500-999 g born in one tertiary centre in the 5 1/4 years commencing January 1977; 86 (33.5%) survived to 2 years of age, corrected for prematurity and 83/86 (96.5%) were fully assessed. The prevalence of cerebral palsy was 10/83 (12%) and 17/83 (20%) had a major impairment. The distribution of weights and heights for 2-year-old boys and girls was significantly lower than for the standard population, as was the head circumference distribution for boys; the distribution of the Mental Developmental Index (Bayley Scales) was not related to the head circumference or body weight at two years or to head-circumference/bodyweight or height ratios. At birth measurements of weight, length and head circumference were under the 3rd percentile for 13/86 (15%), 9/86 (10.5%) and 9/86 (10.5%) respectively. By 2 years of age, weight, length and head circumference were under the 3rd percentile in 23/83 (27.7%), 26/83 (31.3%) and 4/83 (4.8%) respectively. 12 children who were SGA at birth were fully assessed at 2 years; the group of 6, who continued with poor postnatal weight gains (under the 3rd percentile) had the highest rate of major impairment but included were the only extremely SGA twins and the only two major malformations in the study. We found no association of other health problems or unfavourable social factors with poor postnatal growth or impaired outcome.

Blindness↗
PubMed1985

An electromyographic study of elbow motion during postexercise muscle soreness.

Postexercise muscle soreness was induced in the elbow flexors of human volunteer subjects through the use of a regimen of eccentric contractions. Physical examination before and 48 h after the exercise included measurements of range of elbow motion at the elbow and of arm diameter. Electromyographic (EMG) observations, utilizing fine wire electrodes introduced into each of the elbow flexors, were carried out before and 48 h after the exercise. These observations included resting EMG levels, EMG activity under various isometric loads, and activity during active and passive extensions. The soreness induced was accompanied by a reduction in resting elbow angle while the subjects stood with arms relaxed at their sides, decreased range of both flexion and extension of the elbow, and swelling of the arm. EMG measurements showed no increase in EMG activity as the sore arms were extended passively at the elbow, indicating that the extra resistance to extension associated with the soreness was not a result of stretch receptor-induced activity in the flexors. The results rule out the possibility that neuromuscular activity is responsible for the restriction of motion and are consistent with the idea that edematous changes within the perimuscular connective tissue alter the elastic behavior of the muscles and cause restriction of motion.

Adult↗
PubMed1985

The elderly as underconsulters: a critical reappraisal.

This paper reconsiders the evidence for underconsultation among the elderly. Earlier evidence from studies of unreported illness is reassessed and new data are presented for the ratio of self-reported illness to number of consultations. It is concluded that underconsultation among the elderly is exaggerated and that there are implications for screening and case-finding. It is suggested that attention should be directed towards a combination of self-referral and multi-tiered screening for low contact and high risk groups.

Aged↗
PubMed1984

Comparison of polyadenylic acid and oligouridylic acid messenger RNA associated proteins.

Various subclasses of messenger ribonucleoprotein particles were prepared from free cytoplasmic and polysome fractions of rat liver on the basis of the homopolymeric content of the constituent RNA's. Two major proteins were evident in the free cytoplasmic preparations: the poly(A)-binding protein was the major constituent of polyadenylated components and a 60 kilodalton protein was the major protein in oligouridylated components. In addition to the poly(A)-binding protein, the polysome fractions contained a 74 kilodalton protein that was present in all subclasses of particles. With both free cytoplasmic and polysome preparations, chromatography on columns of poly(U)-sepharose separated poly-adenylated mRNP's largely on the basis of the length of the poly(A) tract; mRNP's containing short poly(A) tracts (fragment distribution centered on 34 residues) were not retained by the columns, presumably because of the interaction of the poly(A) with poly(A)-binding protein.

Animals↗