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Biomedical subjects

J Phillips

Publications and source records attributed to J Phillips.

At least 163 records · Page 9Linked to original sources
PubMed1994

Energy metabolism in free-living, 'large-eating' and 'small-eating' women: studies using 2H2(18)O.

The doubly-labelled water (2H2(18)O) technique was used to assess the long-term rates of energy expenditure and, after accounting for any changes in body composition, the derived rates of energy intake in weight-stable 'large-eating' (n 6) and 'small-eating' (n 6) women. The self-reported energy intakes (approximately 11.2 v. 5.6 MJ/d) and energy expenditures (approximately 8.5 v. 12.4 MJ/d) for the 'large-eating' and 'small-eating' groups respectively, should not be sustainable without significant body-weight changes. 2H2(18)O-assessed rates of energy expenditure for the 'large-eaters' (approximately 8.5 MJ/d) and 'small-eaters' (approximately 11.3 MJ/d) were in close agreement with the results obtained using 5 d, self-reported activity diaries but the derived rates of energy intake for the 'large-' (approximately 8.5 MJ/d) and 'small-eaters' (approximately 10.8 MJ/d) were markedly different from those obtained using self-reported, weighed food diaries. When two 'small-eaters' were supplied with their self-reported energy intakes (approximately 5 MJ/d) for up to 28 d both subjects lost about 0.75 kg body-weight/week. These results provide no support for the existence of 'metabolically efficient' women in the community.

Adult↗
PubMed1994

Sources of variance in ocular microtremor.

This study presents a preliminary investigation of the sources of variance in the measurement of ocular microtremor frequency in a normal population. When the results from both experienced and relatively inexperienced operators are pooled, factors that contribute significantly to the total variance include the measurement procedure (p < 0.001), day-to-day variations within subjects (p < 0.001), and inter-subject differences (p < 0.01). Operator experience plays a role in determining the measurement precision: the intra-subject coefficient of variation is about 5% for a very experienced operator, and about 14% for a relatively inexperienced operator.

Adult↗
PubMed1994

Co-segregation of intermale aggression with the pseudoautosomal region of the Y chromosome in mice.

The sexual dimorphism of aggression has led to a search for its Y chromosomal correlates. We have previously confirmed that initiation of attack behavior against a conspecific male is Y-dependent in two strains of laboratory mice (NZB and CBA/H). We provide evidence that the non-pseudoautosomal region of the Y is not involved and that only the pseudoautosomal region of the Y is correlated with initiation of attack behavior. The autosomal correlates also contribute to this behavior in an additive or interactive manner with the pseudoautosomal correlates.

Aggression↗
PubMed1994

Areas of the United States with elevated screening levels of 222Rn.

As part of an Environmental Protection Agency/State cooperative program, 38 of the 48 contiguous states have successfully conducted probability-based surveys of indoor 222Rn. These surveys produced short-term screening measurements in approximately 55,000 randomly selected houses. An objective common to all surveys was to identify geographic regions within the state with elevated screening levels of 222Rn. This paper examines the survey results as they relate to this objective. The 38 states were partitioned into 225 geographic regions and summary statistics of 222Rn concentrations (e.g., arithmetic mean, geometric mean, percentage of houses exceeding a specified level) and associated 95% confidence intervals were calculated for each region. Twenty-four of the 225 regions had arithmetic means exceeding 222 Bq m-3 (6 pCi L-1); these are analyzed in detail.

Air Pollutants, Radioactive↗
PubMed1994

Phenotypic rescue by a bovine transgene in a Cu/Zn superoxide dismutase-null mutant of Drosophila melanogaster.

Null mutants for Cu/Zn superoxide dismutase (CuZnSOD) in Drosophila melanogaster are male sterile, have a greatly reduced adult life span, and are hypersensitive to paraquat. We have introduced a synthetic bovine CuZnSOD transgene under the transcriptional control of the D. melanogaster 5C actin promoter into a CuZnSOD-null mutant of D. melanogaster. This was carried out by P-element-mediated transformation of the Drosophila-bovine CuZnSOD transgene into a CuZnSOD+ recipient strain followed by genetic crossing of the transgene into a strain carrying the CuZnSOD-null mutation, cSODn108. The resulting transformants express bovine CuZnSOD exclusively to about 30% of normal Drosophila CuZnSOD levels. Expression of the Drosophila-bovine CuZnSOD transgene in the CuZnSOD-null mutant rescues male fertility and resistance to paraquat to apparently normal levels. However, adult life span is restored to only 30% of normal, and resistance to hyperoxia is 90% of that found in control flies. This striking differential restoration of pleiotropic phenotypes could be the result of a threshhold of CuZnSOD expression necessary for normal male fertility and resistance to the toxicity of paraquat or hyperoxia which is lower than the threshold required to sustain a normal adult life span. Alternatively, the differential rescue of fertility, resistance to active oxygen, and life span might indicate different cell-specific transcriptional requirements for these functions which are normally provided by the control elements of the native CuZnSOD gene but are only partly compensated for by the transcriptional control elements of the actin 5C promoter.

Animals↗
PubMed1994

Foreign body in the throat.

The management of 104 patients complaining of foreign body (FB) in the throat in an accident and emergency (A&E) department was analysed over a period of 7 months. The majority of these patients (88.4%), underwent a soft tissue radiograph of the neck. Less than 10% of the radiographs were thought to be abnormal by the A&E staff. Two thirds of the patients (69.2%) were referred to the ear, nose and throat (ENT) surgeons. Of these 84.7% had indirect laryngoscopy. Eighteen (17.3%) FBs were found in addition to five (4.8%) other causes of the symptom. It is concluded that routine use of radiographs in the assessment of FB in the throat is inappropriate. By contrast thorough clinical examination and indirect laryngoscopy (IDL) have a high diagnostic yield. A protocol is suggested for managing the condition.

Adolescent↗
PubMed1994

USE OF A SPECIALIZED MAGNETORECEPTION SYSTEM FOR HOMING BY THE EASTERN RED-SPOTTED NEWT NOTOPHTHALMUS VIRIDESCENS

Laboratory experiments were carried out to investigate the effects of varying the wavelength of light on the use of an earth-strength magnetic field for shoreward orientation and for the compass component of homing. In the earlier shoreward orientation experiments, newts tested under full-spectrum and short-wavelength (i.e. 400 and 450 nm) light exhibited shoreward magnetic compass orientation. Under long-wavelength (i.e. 550 and 600 nm) light, newts exhibited magnetic compass orientation that was rotated 90 &deg; counterclockwise to the shoreward direction. This wavelength-dependent shift in magnetic compass orientation was shown to be due to a direct effect of light on the underlying magnetoreception mechanism. In homing experiments, newts tested under full-spectrum and short-wavelength light exhibited homeward magnetic compass orientation. Under long-wavelength light, newts were randomly distributed with respect to the magnetic field. The different effects of long-wavelength light on shoreward orientation and homing confirmed earlier evidence that different magnetoreception systems mediate these two forms of orientation behaviour. The properties of the newt's homing response are consistent with the use of a hybrid magnetoreception system receiving inputs from the light-dependent magnetic compass and from a non-light-dependent intensity (or inclination) detector which, unlike the compass, is sensitive to the polarity of the magnetic field.

Journal Article↗
PubMed1994

Alleles of the microsomal steroid sulfatase gene (Sts) in the pseudoautosomal region of the heterosomes of the mouse.

The gene (Sts) for microsomal steroid sulfatase (STS-EC 3.1.6.2) is located at the distal end of the pseudoautosomal region of the mouse heterosomes. A new improved method was developed to measure the activity of this enzyme in four inbred strains of laboratory mice, their respective congenics for the non pseudoautosomal region of the Y chromosome and their F1s were employed. The method was shown to be highly reliable (.95). No sexual dimorphism was shown but a polymorphism for the enzymatic activity, corresponding to three functional allelic forms was found. The results presented here are compatible with the location of the Sts gene on the X-Y pseudoautosomal region. The underdominance that appears in the F1s, in one set of strains and the difference between reciprocal F1s in the other set must be interpreted cautiously since it is the enzymatic activity which is only measured and not the protein itself. A complex mechanism, involving the gene responsible for the enzyme located on the pseudoautosomal region and autosomal locus or loci which regulate(s) its activity, is suggested as being responsible for the results obtained with the F1s.

Alleles↗
PubMed1994

Chromosomal localization of the human renal sodium phosphate transporter to chromosome 5: implications for X-linked hypophosphatemia.

Hypophosphatemic vitamin D-resistant rickets, an X-linked dominant disorder, is the most common form of vitamin D-resistant rickets in humans (McKusick number 307800). Biochemically, these patients exhibit hypophosphatemia due to a defect in the renal tubular reabsorption of phosphate. The human cDNA encoding for the renal phosphate transporter has been recently cloned using the expression system in the Xenopus laevis oocytes. Because hypophosphatemic vitamin D-resistant rickets has an X-linked mode of transmission, we hypothesized that the gene encoding the renal phosphate transporter might map to the X chromosome. In this report, we determined the chromosomal localization of the human renal phosphate transporter using three independent methods. First, DNA from somatic cell hybrid panels was examined by Southern blotting for the phosphate transporter. Second, the polymerase chain reaction was used to amplify DNA from somatic cell hybrids. Third, fluorescent in situ hybridization was used to sublocalize the renal phosphate transporter. All three methods localized the renal phosphate transporter to chromosome 5q13. Our results indicate that either derangement of a gene other than the phosphate transporter gene that is encoded on chromosome 5 is responsible for X-linked hypophosphatemic rickets or, alternatively, a gene encoded on the X chromosome has an epistatic effect on the expression of the renal phosphate transporter on chromosome 5.

Base Sequence↗
PubMed1994

Absence of a dose-response effect of leuprolide acetate on leiomyomata uteri size.

OBJECTIVE: To evaluate the effects of two different doses (3.75 mg versus 7.5 mg) of leuprolide acetate (LA, Lupron; Tap Pharmaceuticals, Deerfield, IL) on myoma size, blood loss during myomectomy, on magnetic resonance imaging (MRI) signal quality, and histopathologic changes in women requiring myomectomy. DESIGN: Prospective, nonrandomized, sequential study. SETTING: Urban center teaching hospital. PATIENTS: Twenty-eight women with uterine leiomyomata requiring myomectomy. INTERVENTIONS: Nine women were entered as controls (group 1), 10 women received 3.75 mg IM (group 2), and 9 women received 7.5 mg IM of LA (group 3) each for 3 months before myomectomy. RESULTS: The uterine size and hematocrit among the three groups of patients before treatment was not significantly different. A significant reduction of 34.5% and 34.6% in myomata size was seen in groups 2 and 3. The estimated average blood loss at myomectomy was 745 +/- 101 mL, 615 +/- 177 mL, and 722 +/- 192 mL in groups 1, 2, and 3, respectively. The postoperative hematocrit was not different among the three groups (29.8% +/- 0.9%, 30.4% +/- 1.6%, and 29.8% +/- 1.2%). There was no evidence of cytologic atypia, increased mitosis, or change in fibrosis in LA-treated women. There were no characteristic MRI or histologic changes seen after LA treatment as compared with controls. CONCLUSIONS: The results of this study have demonstrated that both doses of LA (3.75 and 7.5 mg) can induce a significant and similar degree of size reduction in myomas and that neither dose of LA aided in the reduction of blood loss at myomectomy and therefore should not be used routinely.

Adult↗
PubMed1993

The limitation of referral level fetal ultrasound examination in the detection of spina bifida in Western Australia, 1990-1991.

OBJECTIVE: To ascertain babies born with spina bifida that was not detected by prenatal ultrasound examination performed after 16 weeks' gestational age at Western Australian referral centres, 1990-1991. DESIGN: A retrospective study of the antenatal ultrasound details of those infants born with spina bifida in Western Australia during the 24-month period, 1990 and 1991. Data were collected by interviewing parents, clinically assessing affected individuals and reviewing genetic, clinical and investigative records, and from the Birth Defects Registry of Western Australia. SETTING: Western Australia, which has a relatively high spina bifida birth prevalence of 1 in 1000, has centralised neonatal medical, surgical and genetic services, and a Birth Defects Registry. This enabled us to ascertain all Western Australian neonates with spina bifida for the purposes of this study. There is no universal maternal serum alpha-fetoprotein (MSAFP) screening program and the performance of ultrasonography at referral level is of variable quality. PARTICIPANTS: Newborns with spina bifida and their parents. MAIN OUTCOME MEASURES: Ultrasound screening for spina bifida was deemed to have failed when referral to a specialist imaging centre for the specific purpose of detecting anatomical abnormality after 16 weeks' gestational age gave a falsely negative result. RESULTS: Of the 47 infants born with spina bifida in 1990 and 1991, ultrasound screening at more than 16 weeks' gestational age was documented and was falsely negative in 14. Six of the 14 had a relevant family or medical history for the condition. Five of the lesions were covered and eight of the patients still survive. CONCLUSION: Ad-hoc fetal ultrasound examination via existing referral centres had obvious limitations in detecting spina bifida in a population at low risk. MSAFP screening has a well documented role in detecting neural tube defects, as eight to 10 of the 14 lesions missed by the referral ultrasonography would have been ascertained in a program of this nature. The study indicated that adequate pre-screening clinical histories were not sought, thus limiting the antenatal testing options offered to at-risk couples. This study emphasised the importance of a statewide review of the specificity and sensitivity of the anatomical fetal ultrasound examination, in view of the expansion of this procedure and its variable quality depending on operator experience and equipment quality.

False Negative Reactions↗
PubMed1993

Hippocampal mossy fiber changes in mice transgenic for the human copper-zinc superoxide dismutase gene.

The copper-zinc superoxide dismutase (SOD-1) gene, located on chromosome 21 and triplicated in Down's syndrome (DS), is suspected to be involved in the neuropathology observed in Alzheimer's disease (AD), DS and physiological aging. In order to explore the effect of an overproduction of SOD-1 in the mouse hippocampus, we investigated the Timm-stained mossy fiber (MF) innervation in the hippocampus of transgenic mice for the human SOD-1 gene (hSOD-1 mice). The results showed a decrease of the MF projection area in the hSOD-1 mice overexpressing the SOD-1 protein. These findings suggest that free radicals could play a role in this particular synaptic loss.

Animals↗