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Biomedical subjects

R Edwards

Publications and source records attributed to R Edwards.

At least 253 records · Page 14Linked to original sources
PubMed1991

Blood pressure patterns in the first three days of life.

Current blood pressure data for healthy newborn infants consist primarily of single measurements of systolic and diastolic pressure in the first 48 hours of life. The purpose of this study was to determine if blood pressure levels are stable or are changing during the first few days of life. To determine blood pressure level and trend, indirect blood pressure was measured on day 1 through day 3 of life in all infants admitted to the well newborn nursery at Hahnemann University Hospital in Philadelphia. Systolic pressure correlated significantly with birthweight on day 1 of life (P less than .03). Repeated measures analysis of variance demonstrated a significant increase in both systolic and diastolic pressures over the first 72 hours of life (P less than .001). There was no difference in blood pressure among racial groups (black, Hispanic, white, Asian). In healthy newborns, there was no correlation of blood pressure with maternal conditions: toxemia, diabetes, substance abuse. These data demonstrate that blood pressure correlates with birthweight in well newborns. There is, however, a significant progressive increase in both systolic and diastolic blood pressure over the first 3 days of life, regardless of birthweight or maternal conditions.

Analysis of Variance↗
PubMed1991

Agglutination of blood cardioplegia by cold-reacting autoantibodies.

Cold-reacting autoantibodies occasionally occur in patients requiring cardiac operations. This report describes the clinical course of 1 patient with cold-reacting autoantibodies and intracoronary agglutination of the blood cardioplegia solution. Observations made in vivo and in vitro are considered in discussing recommendations for the management of extracorporeal circulation and cardioplegic arrest in patients with clinically silent cold-reacting autoantibodies.

Aged↗
PubMed1990

Monitoring mutagenicity in urine and peripheral blood lymphocytes of pharmacists occupationally exposed to anticancer drugs.

Two approaches to mutagenicity monitoring were compared for estimation of possible absorption of cytotoxic drugs by a group of six pharmacists at Auckland Hospital. Blood samples were taken before and after a three week duty roster, from age and sex matched negative controls, and from a matched group of patients on chemotherapy. Peripheral blood lymphocytes were fixed, stained and analysed for sister chromatid exchange (SCE). Urine samples were collected from the pharmacists on the morning following their last day on cytotoxic dispensing duty, as well as from positive and negative controls. Samples were concentrated and analysed for mutagenicity in the bacterial Ames test. Comparison of negative control groups with the pharmacists using either of these test measures gave no evidence for significant absorption of cytotoxics by the pharmacist group as a whole, although values for the positive control groups were raised significantly in a similar comparison. The value for SCE of one pharmacist however, was elevated in the second sample (after three weeks dispensing duty) when compared with the first sample (before duty) and the urine analysis also suggested that this individual might have absorbed some mutagens. The results permit a comparison of these techniques as a means of ongoing monitoring of similar populations within New Zealand.

Antineoplastic Agents↗
PubMed1990

Abnormal plant development and down-regulation of phenylpropanoid biosynthesis in transgenic tobacco containing a heterologous phenylalanine ammonia-lyase gene.

Biosynthesis of phenylpropanoid natural products in tobacco was perturbed by introduction of a heterologous (bean) phenylalanine ammonia-lyase (PAL; L-phenylalanine ammonia-lyase, EC 4.3.1.5) gene, modified by inclusion of cauliflower mosaic virus 35S enhancer sequences in its promoter. These transgenic plants can exhibit a series of unusual phenotypes including localized fluorescent lesions, altered leaf shape and texture, reduced signification in xylem, stunted growth, reduced pollen viability, and altered flower morphology and pigmentation. Genetic analysis of a transformant with severe symptoms showed that symptom development was inherited as a single, partially dominant trait and cosegregated with reduced levels of PAL activity and soluble phenylpropanoid products. Accumulation of transcripts encoded by the endogenous tobacco PAL genes was suppressed. We conclude that the transgene disrupts PAL regulation and that some of the phenotypes reflect interference with putative signals dependent on phenylpropanoid biosynthesis.

Journal Article↗
PubMed1990

Rare ectopic pregnancies after in-vitro fertilization: one unilateral twin and four bilateral tubal pregnancies.

Between 1985 and 1989, one unilateral twin and four bilateral tubal pregnancies were encountered among 124 extrauterine pregnancies and 1648 intrauterine pregnancies following in-vitro fertilization and embryo transfer. The two factors associated with this high incidence of single and multiple extrauterine pregnancies were tubal damage and multiple embryo transfer. Embryos at different stages of development appear to have the capacity to implant ectopically. Despite advances in diagnostic capabilities, ectopic pregnancy remains a major cause of maternal mortality. Early diagnosis prior to rupture must be made if mortality and morbidity are to be abolished. The use of transvaginal sonography has improved the diagnosis of ectopic pregnancy and should be routinely used in all pregnancies following assisted conception. The identification of an intrauterine pregnancy should not be sufficient to rule out the possibility of an extrauterine pregnancy or even bilateral tubal pregnancies.

Adult↗
PubMed1990

Effect of growth conditions and storage on the specific activity of beta-lactamases of Bacteroides spp.

The influences of growth conditions and cold storage on the specific activity of beta-lactamases of four strains of Bacteroides spp. was studied. Interbatch variation was observed in extracts prepared in an identical way on separate occasions but less variation was observed in extracts prepared from bacteria grown on Brain Heart Infusion agar supplemented with yeast extract, haemin and menadione, than in similar extracts of bacteria grown in broth or on other solid media. The loss of enzyme activity seen during the stationary phase of growth of some strains in broth was minimal during incubation for 48 h on agar. Storage of enzyme extracts at 4 degrees C was associated with loss of enzyme activity, but activity was retained during storage at -70 degrees C for up to 32 days. Freezing and thawing had little effect on enzyme activity.

Bacteroides↗
PubMed1990

Morbidity, mortality and survival following resection for carcinoma of the rectum at Concord Hospital.

Colorectal cancer is the most common internal malignancy in Australia, and the rectum is the most common site. The morbidity, mortality and survival of 561 consecutive patients with rectal cancer who had a resection at Concord Hospital during the 16-year period 1971-86 were evaluated. More than half of the operations performed were low anterior resections (LAR), with total abdominoperineal excisions (APE) of the rectum comprising another third. There was a 5.1% mortality rate in LAR patients and a 3.1% mortality rate in the APE group. Respiratory complications, urinary tract infections and wound infections were the most common causes of morbidity in both LAR and APE. The median survival for patients treated by LAR and APE standardized for clinicopathological staging was 111.5 and 47.1 months (A), 79.0 and 65.5 months (B), 41.3 and 28.5 (C), and 14.7 and 12.4 (D), respectively.

Adult↗
PubMed1990

Response of isolated intracerebral arterioles to endothelins.

The effects of endothelin-1, -2 and -3 (ET-1, -2, -3) on lumen diameter of intracerebral arterioles isolated from rat brain were examined. All three ETs produced concentration-dependent decreases in lumen diameter with EC50 values of 0.7, 1.5 and 58 mmol/l for ET-1, ET-2 and ET-3, respectively. The calcium channel antagonist, nicardipine, had no significant effect on ET-1-induced contractions except at a concentration of 1 mumol/l which attenuated the maximum response to ET-1, but had no effect on the EC50 value. The potent vasoconstrictor action of ET on intracerebral arterioles suggest an important role for this peptide in the regulation of the cerebral microvasculature.

Animals↗
PubMed1990

Human follicular fluids contain tissue macrophages.

Tissue cells obtained from the follicular fluids of women undergoing in vitro fertilization and embryo transfer were found to contain interleukin-1 beta mRNA by Northern analysis. Since macrophages are known to produce interleukin-1 beta, we examined the follicular fluids of 20 women undergoing in vitro fertilization as well as tissue sections of normal human ovary for the presence of macrophages and monocytes. Although granulosa-luteal cells predominate in follicular fluid, we found that resident macrophages and monocytes comprise 5-15% of human follicular tissue cells. In addition, we observed that macrophages are present in the human ovarian follicle as well as in the corpus luteum.

Blotting, Northern↗
PubMed1990

Measurements of human bioluminescence.

In measuring the output of light from the human skin, we estimated the total photon rates to be of the order of 170-600 photons/s/cm2, depending on anatomical location. The light was strongest at the red end of the spectrum, but fell below detectable levels in the ultraviolet. Significant variations were observed between individuals in both photon rate and spectral profile. The photon rate also varied significantly with time for a single individual. The possible source of this light and its significance are discussed.

Equipment Design↗
PubMed1990

Ovarian remnant syndrome: difficulties in diagnosis and management.

Ovarian remnant syndrome should be considered in the differential diagnosis of pelvic pain with a mass in a patient who has had extirpative surgery. Although rarely reported in the literature, it is probably much more prevalent than is suspected. Most commonly, the initial surgery was performed for endometriosis or pelvic inflammatory disease, with incomplete excision of the ovaries. Surgical excision of the ovarian remnant, the definitive treatment, is itself difficult, and is often attended by serious complications. Medical therapy is empiric, and hormonal manipulation may help prevent recrudescence. Three cases are reported, their pathology and the literature is reviewed.

Adult↗
PubMed1989

Urinary growth hormone during puberty in normal and diabetic children.

The measurement of GH in urine may have many clinical applications, particularly in childhood. We have used a highly sensitive direct immunoradiometric assay to examine urinary GH excretion in children during puberty. Fifty-five healthy schoolchildren collected timed overnight urine samples. A further 36 children (15 normal, six of short stature and 15 diabetic) collected urine samples during a total of 50 overnight plasma GH secretory profiles (15-min sampling). Overnight urinary GH excretion increased during puberty, with a peak at breast stage 2 in girls, and genital stage 4 in boys, before declining at stage 5. There was a positive correlation (r = 0.57, p = 0.003) with height velocity in girls, but not in boys. At each puberty stage except 2, the diabetics excreted more urinary GH than the normal children. There was a highly significant correlation (r = 0.79, p less than 0.001) between mean overnight plasma GH concentrations and urinary GH excretion, suggesting that the latter accurately reflects physiological GH secretion.

Adolescent↗
PubMed1989

Theophylline pharmacokinetics in patients with bronchopulmonary dysplasia.

Theophylline is commonly used to decrease airway resistance in patients with bronchopulmonary dysplasia (BPD). Little is known, however, about theophylline's pharmacokinetics in infants' with BPD. The objectives of this study were: (i) to examine the pharmacokinetics of theophylline; and (ii) to assess the intrapatient variation in theophylline serum concentration in BPD. Nineteen patients (gestational age: 27-33 weeks, postnatal age: 12-165 days) received 2-12 mg/kg/day theophylline. Multiple serum concentrations of theophylline were determined in each patient. Apparent clearance of theophylline ranged from 0.28 to 0.51 ml/min/kg. The steady-state trough serum concentration of theophylline ranged from 3.5 to 11.2 micrograms/ml. Based on our data, theophylline doses of 4-7 mg/kg/day may be required to achieve an average steady-state serum concentration of 10 micrograms/ml. Substantial intrapatient (twofold) variability was observed in theophylline concentrations normalized for dose during therapy. The data indicate that the theophylline serum concentration should be monitored for individualizing therapy in infants with BPD.

Aging↗
PubMed1989

Measurement of human growth hormone in urine: development and validation of a sensitive and specific assay.

A specific solid-phase immunoradiometric assay (IRMA), optimized for maximum sensitivity, has been developed for measurement of human GH (hGH) in urine. The sensitivity varied with sample size, giving a range of 0.001 to 0.003 mU/l for a sample volume of 2 ml. Recovery and dilution experiments, together with chromatography of urine samples, indicate that the method is specific for hGH. Added exogenous hGH was measured with a mean recovery of 101 +/- 10% (S.D.) for 1 ml samples and 87 +/- 8% for 2 ml samples. Measurements of samples diluted at 1:2 and 1:4 gave values of 97.4 and 96.6% respectively of those expected. Cross-reactions of human placental lactogen and prolactin were less than 0.008 and 0.04% respectively on a mol/mol basis. The assay was insensitive to the presence of NaCl (50-500 mmol/l), urea (50-1000 mmol/l), creatinine (1-20 mmol/l), Ca2+ ions (1-20 mmol/l), SO4(2-) ions (1-1000 mmol/l), Mg2+ ions (0.05-50 mmol/l), 0.5-5% (w/v) glucose and a pH range of 6-9. Chromatography of unextracted samples showed that the immunoreactive material in urine eluted in a single homogenous peak with a similar position to monomeric pituitary hGH (22 kDa). Administered hGH (0.002%) was recovered in urine collected over a 2-h period following an intravenous injection. The urine output of hGH showed a good correlation with serum hGH in 18 patients following routine insulin tolerance tests and in 25 patients following an oral glucose tolerance test.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗