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Biomedical subjects

J M Foster

Publications and source records attributed to J M Foster.

At least 37 records · Page 2Linked to original sources

Cloning and sequence analysis of GmII, a Drosophila melanogaster homologue of the cDNA encoding murine Golgi alpha-mannosidase II.

Using the murine cDNA that encodes Golgi alpha-mannosidase II (GlcNAc transferase I-dependent alpha 1,3[alpha 1,6] mannosidase; EC 3.2.1.114) as a probe to screen a cDNA library made from Drosophila melanogaster (Dm) embryos, we have isolated GmII, the Dm sequence homologue. The 3926-bp cDNA has an open reading frame of 3327 bp and predicts a polypeptide of approx. 127 kDa, a mass similar to that of the murine protein. The deduced mouse and Dm amino acid (aa) sequences share extensive similarity across their entire lengths and are both type-II transmembrane (TM) proteins with short cytoplasmic tails, single TM domains and large hydrophilic C-terminal domains. A region of approx. 200 aa, within the C-terminal domain, has considerable similarity to a corresponding region from several other alpha-mannosidases. GmII has been localized to a single site (85D14-18) on the right arm of chromosome 3.

Amino Acid Sequence↗

Correlation of pain with temperature and blood-flow changes in the lower limb following chemical lumbar sympathectomy in reflex sympathetic dystrophy. A case report.

Temperature and microcirculatory blood flow studies have been measured before and after chemical sympathectomy in a patient with reflex sympathetic dystrophy of the left leg present for at least three years following surgery for glomus tumour. Normalisation of temperature and blood flow was associated with the relief of pain, present initially when the limb was hypothermic and vasoconstricted and recurring when the limb was hyperthermic and vasodilated. It is possible that such objective measurement may be used to determine the optimal management of RSD.

Aged↗

Is chest pain after sumatriptan oesophageal in origin?

3-5% of patients taking the 5HT1D agonist sumatriptan for migraine have chest discomfort, suggesting a cardiac origin. We have investigated an alternative explanation of an oesophageal cause in 24 volunteers after the subcutaneous administration of a supratherapeutic dose of sumatriptan (16 mg) or placebo in a randomised, double-blind crossover study. Sumatriptan did not alter the electrocardiogram but increased the amplitude (p < 0.001) and duration (p < 0.001) of oesophageal contractions without affecting velocity of propagation. Clinically abnormal motility was also increased (p = 0.001), and was more common in the 5 subjects with chest pain after sumatriptan. The effect of sumatriptan on oesophageal function provides an alternative explanation for the chest symptoms.

Adult↗

Biosynthesis of isoprenoid compounds in Schistosoma mansoni.

The isoprenoid biosynthetic capacity of digenetic trematodes was investigated by following the fate of [14C]mevalonic acid incorporated by Schistosoma mansoni during maintenance in axenic culture. Isoprenoid compounds were analyzed by thin-layer chromatography and high-performance liquid chromatography. Of the nonsaponifiable lipid classes, radioactivity was recovered in the dolichols, ubiquinones and in the short-chain isoprenoid alcohols. The latter group of lipids included geraniol, farnesol, geranylgeraniol and a compound tentatively identified as 2,3-dihydrogeranylgeraniol. Radioactivity derived from [14C]mevalonate was also incorporated into the saponifiable lipids, with 2,3-dihydrogeranylgeranoic acid accompanied by much less geranylgeranoic acid being detected in the triacylglycerol-containing fraction. Similarly, geranylgeraniol and the dihydro derivative were also detected as esters, presumably with fatty acids. The possible significance of the results is discussed.

Alcohols↗

Analysis of ecdysteroids in the trematodes, Schistosoma mansoni and Fasciola hepatica.

Adult Schistosoma mansoni from experimentally infected mice and Fasciola hepatica recovered from ovine livers post mortem were analyzed for free and conjugated ecdysteroids by radioimmunoassay, high-performance liquid chromatography monitoring fractions by radioimmunoassay, and by capillary gas chromatography/mass spectrometry (selected ion monitoring). Both species contained ecdysone and 20-hydroxyecdysone as free ecdysteroids and as polar conjugates. F. hepatica also contained a polar conjugate of 2-deoxyecdysone. Evidence of apolar ecdysteroid conjugates was only obtained for F. hepatica. The free ecdysteroid-containing fraction of S. mansoni contained small amounts of unidentified immunoreactive material.

Animals↗

Hyperoxia potentiates Ureaplasma urealyticum pneumonia in newborn mice.

The effect of continuous exposure to 80% oxygen on newborn mice with Ureaplasma urealyticum pneumonia was determined. Mice were inoculated intranasally with either U. urealyticum or sterile broth and then housed in either 80% oxygen or room air (21% oxygen). The mice were sacrificed at either 7 or 14 days after inoculation. Significantly more mice in the U. urealyticum group housed in 80% O2 than in the room air-exposed group were culture positive 14 days after inoculation (P = 0.042), but no difference was found at 7 days. The presence of alveolar macrophages, neutrophils, and lymphocytes and alveolar wall thickness were determined. Overall, the group housed in 80% O2 and inoculated with U. urealyticum had severe pulmonary lesions at both time points, while the lesion severity in the room air-exposed group inoculated with U. urealyticum and the group housed in 80% O2 and inoculated with sterile broth was dependent on the time point. Mortality was significantly higher in the group housed in 80% O2 and inoculated with U. urealyticum than it was in all other groups (P less than 0.001). Our results indicate that hyperoxia causes the persistence of U. urealyticum in the lungs of newborn mice, acutely potentiates the inflammatory response, and turns an otherwise self-limited pneumonia into a lethal disease.

Animals↗

Prematurity, postdates, and growth retardation: the influence of use of ultrasonography on reported gestational age.

The preterm and postterm delivery rates and the percentage of infants with intrauterine growth retardation are dependent on the gestational age recorded at delivery. At our institution a sharp increase in the preterm delivery rate and a coincident decrease in the postterm delivery rate and the rate of intrauterine growth retardation were noted. Over a 3-year period, while the characteristics of the obstetric population changed only slightly, the gestational age distribution shifted, with a decrease in the mean gestational age of about 1 week and a risk in the reported preterm delivery rate from 12% to 17%. About 15% of this rise was explained by an increase in obstetric interventions, and another 15% can be explained by changes in the way physicians rounded off gestational age. The majority of the increase in the preterm delivery rate was related to changes involving ultrasonographic examinations. These changes included a greater percentage of the population examined, trends toward earlier examinations, a tendency for the physicians to use ultrasonography rather than the last menstrual period in choosing the final gestational age, the use of different standards, an increase in the number of structures measured, and the weight given to various structures for determination of gestational age. It is apparent that changes in use of ultrasonography had a profound effect on the reported gestational age distribution at our institution.

Birth Weight↗

Intrauterine growth retardation: standards for diagnosis.

An intrauterine growth-retarded infant is commonly defined as one weighing less than the 10th percentile in birth weight for its gestational age. However, because there is no standard population from which to derive these percentiles, the birth weights that serve as the cutoff point in various published studies may differ by several hundred grams at any gestational age. For this reason, we examined the studies from which the currently used 10th-percentile standards are derived to determine which factors may be responsible for the variation. In addition to obvious differences in the populations and geographic areas on which they were based, studies differed in how gestational age was determined, whether the gestational age was "rounded" or given in completed weeks, which types of infants were excluded, whether the studies were hospital or population based, and whether they were controlled for sex of the infant and race and parity of the mother. These differences in study methodology may be as or more important than the population differences in defining the 10th percentile cutoffs. A single national standard for intrauterine growth retardation would allow comparison between studies of risk factors, diagnostic tests, management, and long-term follow-up status of fetuses and infants with intrauterine growth retardation.

Birth Weight↗

Maternal serum alpha-fetoprotein prenatal screening for Down syndrome.

The relationship between maternal serum alpha-fetoprotein (MSAFP) levels, maternal age and Down syndrome risk factors were studied in the greater Birmingham and North Alabama areas. After adjustment for race and maternal weight, 3.84 percent of women in this study were determined to have Down syndrome risk factors equal to or greater than that of a 35 year old woman with a normal pregnancy. Maternal weight adjustment was of special importance, reducing the number of MSAFP values considered low from 5.12 percent to 3.40 percent. The use of race and area specific medians was also important in the use of prenatal MSAFP screening for Down syndrome affected pregnancies.

Body Weight↗

Lumbar sympathectomy in the management of rectal tenesmoid pain.

Lumbar sympathectomy was performed in twelve patients whose main or sole complaint was rectal tenesmus resulting from pelvic carcinoma, and in whom psychotropic drugs had failed to control their symptom. Following bilateral chemical lumbar sympathectomy, ten patients achieved complete relief and one patient achieved partial relief. No patient achieving relief had recurrence of their tenesmoid pain. Patients were followed up for between three days and seven months. No complications were noted except temporary hypotension in one patient. It is concluded that lumbar sympathectomy is a safe and effective treatment for rectal tenesmus and may be the treatment of choice if pharmacological methods have failed to control this symptom.

Adult↗

The mechanisms of acupuncture analgesia.

Despite ever-increasing popularity as a quick, effective and safe means of pain control, acupuncture is still regarded with some suspicion in conventional medical circles. Nevertheless evidence is accumulating to support a firm physiological basis for its action, a fuller understanding of which will shed light on the essence of pain itself.

Acupuncture Therapy↗

Fetal deaths in Alabama, 1974-1983: a birth weight-specific analysis.

Birth weight-specific fetal death rates were evaluated for Alabama for the years 1974-1983. The fetal death rate for the total low birth weight group improved less than 20% during the decade, whereas the fetal death rate for the 2500-3999-g birth weight group improved 40%, and the fetal death rate for the group of 4000 g or more improved 71%. By 1983, 76% of all stillbirths weighed less than 2500 g, compared with 66% in 1974. In contrast, in both years, only about 7% of live births weighed less than 2500 g. This study suggests that increased reporting of stillbirths of less than 500 g has contributed to the recent apparent lack of improvement in stillbirth rates in Alabama.

Alabama↗

An exploratory study comparing depressed and nondepressed elders' coping strategies.

Thirty-two nondepressed elders were given a self-report coping behavior measure that asked them to identify strategies used in response to a recent major life event, and the experience of "feeling down" or "depressed." The measure also asked the subjects to rate how helpful each coping technique was. The data was compared with those gathered from a depressed elderly sample of equal size, chosen by a post hoc matching method from a population of outpatients undergoing treatment for a separate study. The depressed group reported a greater use of avoidance coping behavior than did the nondepressed sample; they were also significantly more likely to use emotional discharge as a coping technique. The nondepressed population consistently rated all methods of coping as more helpful than did the depressed sample, regardless of frequency of use.

Adaptation, Psychological↗