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Biomedical subjects

W E Allen

Publications and source records attributed to W E Allen.

At least 55 records · Page 3Linked to original sources
PubMed1988

Duration of symptoms and disc configuration in chemonucleolysis.

Previous studies have compared the effectiveness of chemonucleolysis with surgery, but currently, no objective criteria have been correlated with the clinical outcome. The authors reviewed 28 cases where the patients had undergone chymopapain injection to determine the significance of disc herniation size, disc space height reduction, and the duration of symptoms on clinical outcome. All patients had a complete history, physical examination, and discogram, and most had pre- and post-injection computerized tomography (CT) or myelogram. Nine of the 28 patients were considered clinical failures. Seven underwent laminectomy and discectomy and were improved markedly. Two patients were advised to have surgery but refused and were considered clinical failures. The causes of failure were unknown in three patients, free fragment in two patients, and diabetic neuropathy in one. Only two patients who did well showed complete resolution of the disc deformity on repeat CT scan. The remainder still had evidence of an avascular deformity that persisted although reduced in size. The failures showed no changes in disc size. The height of the disc space was too variable to be correlated with clinical outcome. Patients who failed had a longer duration of symptoms than the ones who did well (15.1 months for failures vs. 5 months). Therefore, some reduction of disc deformity size, but not necessarily complete reduction, is necessary for a good result, and the enzyme is not as effective in patients with long-standing symptoms.

Adult↗
PubMed1988

The effect of various antibacterial preparations on the in vitro morphology and chemotactic response of equine neutrophils.

Two independent assay systems were used to study the effect of three antibacterial preparations on in vitro morphology and chemotaxis of equine neutrophils. Incubation of neutrophils with high (200 micrograms/ml) and medium (20 micrograms/ml) concentrations of neomycin impaired their response to standard chemoattractants. Trimethoprim/sulfadoxine (0.4/2.0 micrograms/ml-40/200 micrograms/ml) and benzylpenicillin (0.25-25 micrograms/ml) had no effect. Neutrophils collected from geldings 2 and 24 h after neomycin (5 mg/kg) administration had impaired responses to standard chemoattractants. Benzylpenicillin (13.2 mg/kg) had no effect.

Animals↗
PubMed1987

Comparison of radioimmunoassay and enzyme-linked immunoassay for the measurement of progestogen in equine plasma and milk.

Milk and plasma samples were obtained every 48 hours from eight pony mares for 40 days after foaling. Progestogen concentrations in milk and plasma were measured using an enzyme-linked immunoassay (ELISA) and compared with radioimmunoassay of the plasma. In general the three assays showed similar trends in progestogen concentration changes but absolute values varied considerably. Difficulty could occur in interpreting the results from single samples taken at times when progestogen concentrations were either rising (ie, after ovulation) or falling. ELISA could be used on plasma obtained by allowing the erythrocytes to settle for 30 minutes at room temperature or for two days at 4 degrees C.

Animals↗
PubMed1987

Absorption of neomycin from the equine uterus: effect of stage of oestrous cycle and volume of vehicle.

Plasma concentrations of neomycin were measured following intrauterine infusion of 3.3 mg/kg bodyweight neomycin sulphate. Mares in oestrus absorbed approximately 6 per cent of neomycin infused whereas mares in a luteal phase absorbed 56 per cent. The volume of infusate also affected absorption as increased volume resulted in decreased absorption. The decreased absorption both during oestrus and when large volumes were used was probably due to reflux of antibiotic through the cervix.

Absorption↗
PubMed1987

Rapid, single-step isolation of equine neutrophils on a discontinuous Percoll density gradient.

A rapid single-step procedure for isolation of equine neutrophils (PMNS) from peripheral blood is described. A discontinuous gradient of two Percoll solutions (densities of 1.087 kg litre-1 and 1.108 kg litre-1 was used. The PMNS were isolated to more than 95 per cent purity with a viability of more than 99 per cent and a cell recovery of more than 83 per cent. The method used was rapid and reproducible and the equipment required is relatively simple. The function of the recovered cells was assessed in a chemotactic assay using a modified Boyden chamber technique.

Animals↗
PubMed1986

The use of catheter-tipped pressure transducers for chronic measurement of genital tract pressures in the ewe. II. Effects of oxytocin and prostaglandin F(2)alpha.

Chronic catheterisation of the uterus, ampulla, and abdomen was performed in five ewes using solid-state, catheter-tipped pressure transducers. The catheters remained in place for up to 129 d, allowing in vivo studies of the effects of oxytocin and prostaglandin F(2)alpha (PGF(2)alpha). These agents did not produce any measurable increase in abdominal pressure. Intravenous (i.v.) oxytocin elicited a rapid increase in work done by both the uterus and ampulla. Intramuscular (i.m.) PGF(2)alpha produced a delayed uterine response but little change in the ampulla; i.v. PGF(2)alpha produced a rapid response at both sites. Low plasma progesterone concentrations (< 0.5 ng/ml) were associated with a greater uterine and ampullary response to oxytocin and with an enhanced uterine response to PGF(2)alpha. However, the uterine tube response to intravenous PGF(2)alpha was greatest when plasma progesterone concentrations were high.

Journal Article↗
PubMed1985

Genital tract pressures in mares. I. Normal pressures and the effect of physiological events.

A computerised system involving electronic catheter-tipped transducers was used to measure pressures developed within the vagina and uterus of mares. Larger mares tended to have lower intravaginal pressure than ponies. Insertion of an arm into the vagina to place the catheters caused a rise in intravaginal pressure. Pressure in the uterus was usually higher than that in the vagina. Both vaginal and uterine pressures were increased by urination, snorting, whinnying, stretching and respiration - the latter effect was most noticeable in larger mares. Vaginal pressure was also influenced by peristalsis in the rectum, defaecation, the passage of flatus and the stance of the mare.

Journal Article↗