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Biomedical subjects

J Miles

Publications and source records attributed to J Miles.

At least 91 records · Page 5Linked to original sources
PubMed1988

Stabilisation of the infected spine.

A metal stabilising rod was inserted at the time of surgical drainage of the abscess in six patients with spinal instability secondary to vertebral osteomyelitis. The procedure enabled early postoperative mobilisation to be undertaken in five patients. All cases obtained immediate relief of pain. One case of delayed wound healing occurred but not late recurrent infections were encountered after discontinuing antibiotic therapy. The technique was employed in cases of pyogenic as well as tuberculous spinal osteomyelitis.

Abscess↗
PubMed1988

Proficiency testing in clinical cytogenetics. The 1986 experience of the College of American Pathologists.

In 1986, the College of American Pathologists introduced a proficiency testing program in cytogenetics entitled "survey CY." Approximately 140 laboratories actively participated. The survey consisted of 20 cytogenetic cases sent to the participants in quarterly shipments of five challenges each. Photographic negatives of metaphases were the primary medium studied. The results reported by the participants were highly concordant for the determination of modal chromosome count and sex chromosome designation. More than 90% of the participants correctly identified the following abnormalities: trisomies 8, 13, 18, 21, and X; monosomy X; t(9;22); t(8;21); der(2) t(2;?); and 5p-. Abnormalities A fra(X)(q27), t(5;11), inv(16), and t(15;17) were correctly identified by more than 80%, 70%, 70%, and 60% of the participants, respectively. The participants had the most difficulty with diagnoses that involved photographs of high-resolution chromosome banding. The 1986 survey was not graded, but the 1987 cytogenetics survey will be scored on those challenges where there is at least 80% consensus among the participants.

Chromosome Aberrations↗
PubMed1987

Influence of specimen treatment on nonreactive HTLV-III sera.

We investigated effects of specimen treatment on HTLV-III antibody assay results. Freezing and thawing specimens 10 times did not increase specimen mean absorbance (A) values measured by the Abbott immunoenzymometric assay (IEMA). Heating blood donor serum specimens at 56 degrees C for at least 10 min inactivates virus, but converted 7.1% of nonreactive specimens to positive when measured by this IEMA. Also heating at 56 degrees C for 30 min increased A values of most specimens; however, the conversion to positive within assay ranged from 0 to 75%, with a mean of 17%. When 56 nonreactive patient specimens were heated, 55% became Abbott IEMA reactive, although ENI IEMA values did not increase and Western blot results remained nonreactive. Binding of immunoglobulins G and A to Abbott IEMA beads did not cause this conversion after heat treatment. We postulate that heating specimens causes alteration of some serum matrices and introduces nonspecific binding to assay bead antigen or antibody reagents. We recommend that for the Abbott IEMA, specimens may be stored frozen, and must not be heated to avoid altered reactivity.

Antibodies, Viral↗
PubMed1987

Factors predicting response of end stage squamous cell carcinoma of the head and neck to cisplatinum.

Cisplatinum significantly prolongs survival in end stage head and neck cancer but only 30-40% of patients respond. Many receive chemotherapy with little or no benefit and it would obviously be advantageous to determine in advance those patients likely to benefit. In 2 phase III trials of chemotherapy in end stage disease, 129 patients have been treated with cisplatinum, either alone or in 2-drug combination with bleomycin, methotrexate or 5-fluorouracil. Factors analysed in the entire group were age, sex, site, previous treatment, performance status and the use of cisplatinum in combination. A high albumen and oro- or nasopharyngeal site were significantly favourable, while a hypopharyngeal, middle ear, skin or paranasal site were all significantly unfavourable. In the separate analysis of the subgroup with recurrent disease, site of recurrence and time to recurrence were analysed in addition to the factors named above. Although similar trends to those in the entire group were observed none reached significant levels. In the subgroup with advanced previously untreated disease, histological grade was analysed in addition to the above factors. Good performance status emerged as significantly favourable. The emerging trends provide some insight regarding outcome but are not sufficiently clearcut to allow a decision to be made on who should and who should not be treated.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

Determination of Krebs cycle metabolic carbon exchange in vivo and its use to estimate the individual contributions of gluconeogenesis and glycogenolysis to overall glucose output in man.

Current isotopic approaches underestimate gluconeogenesis in vivo because of Krebs cycle carbon exchange and the inability to measure intramitochondrial precursor specific activity. We therefore applied a new isotopic approach that theoretically overcomes these limitations and permits quantification of Krebs cycle carbon exchange and the individual contributions of gluconeogenesis and glycogenolysis to overall glucose output. [6-3H]Glucose was infused to measure overall glucose output; [2-14C]acetate was infused to trace phosphoenolpyruvate gluconeogenesis and to calculate Krebs cycle carbon exchange as proposed by Katz. Plasma [14C]3-OH-butyrate specific activity was used to estimate intramitochondrial acetyl coenzyme A (CoA) specific activity, and finally the ratio between plasma glucose 14C-specific activity and the calculated intracellular phosphoenolpyruvate 14C-specific activity was used to determine the relative contributions of gluconeogenesis and glycogenolysis to overall glucose output. Using this approach, acetyl CoA was found to enter the Krebs cycle at twice (postabsorptive subjects) and three times (2 1/2-d fasted subjects) the rate of pyruvate, respectively. Gluconeogenesis in postabsorptive subjects (3.36 +/- 0.20 mumol/kg per min) accounted for 28 +/- 2% of overall glucose output and increased twofold in subjects fasted for 2 1/2-d (P less than 0.01), accounting for greater than 97% of overall glucose output. Glycogenolysis in postabsorptive subjects averaged 8.96 +/- 0.40 mumol/kg per min and decreased to 0.34 +/- 0.08 mumol/kg per min (P less than 0.01) after a 2 1/2-d fast. Since these results agree well with previously reported values for gluconeogenesis and glycogenolysis based on determinations of splanchnic substrate balance and glycogen content of serial liver biopsies, we conclude that the isotopic approach applied herein provides an accurate, noninvasive measurement of gluconeogenesis and glycogenolysis in vivo.

3-Hydroxybutyric Acid↗
PubMed1987

The place of thalamotomy in the treatment of parkinsonism.

L-Dopa therapy, like thalamotomy, is capable of suppressing some of the symptoms of Parkinsonism but is not a cure. The side effects of L-Dopa therapy can prove as incapacitating as the original symptoms of Parkinsonism. There remains a place for thalamotomy in the treatment of selected cases where symptoms are mainly localised, particularly to the non-dominant limbs, and it has also shown itself to be effective in suppressing dyskinetic movements due to L-Dopa.

Aged↗
PubMed1986

Translocation (4;11) in acute myelogenous leukemia.

A child with acute myelogenous leukemia is presented. Cytogenetic analysis of her leukemic cells revealed a (4;11)(q12;q23) translocation. The slight difference in the breakpoint on chromosome #4 from previously reported cases of t(4;11) may account for the degree of myeloid differentiation expressed. Acute leukemia associated with t(4;11) is a unique subgroup that originates in an early myeloid stem cell and carries a poor prognosis.

Bone Marrow↗
PubMed1985

An evaluation of ultrastrong polyethylene fiber as an ophthalmic suture.

An ultrastrong polyethylene fiber was evaluated as an ophthalmic suture. Properties of this fiber and of nylon, polypropylene, and polyester sutures were measured by standard techniques for fiber testing and for testing knot characteristics of sutures. Their behavior in cataract and keratoplasty surgery was assessed qualitatively. The ultrastrong polyethylene fiber has great tensile strength, high flexibility, and is very inelastic. Its strength and knot security provide safe incision closure and it has good biocompatibility. Ultrastrong polyethylene fiber is potentially superior to nylon, polypropylene, and polyester in the most important characteristics of a non-absorbable monofilament polymer ophthalmic microsuture.

Biocompatible Materials↗
PubMed1985

Apparent decreased oxidation and turnover of leucine during infusion of medium-chain triglycerides.

A potential effector of the protein-sparing adaptation to fasting could be the increased availability of endogenous long-chain fatty acids. Were this hypothesis correct, infusion of medium-chain triglycerides to increase the plasma concentration of medium-chain fatty acids might also result in protein sparing. However, in most in vitro studies in rat muscle, octanoate increases the oxidation of the essential amino acid leucine. Therefore leucine metabolism was assessed with infusions of [3H]leucine and a-[14C]ketoisocaproate ([14C]KIC) before and during an infusion of trioctanoin in conscious dogs. Plasma octanoate increased from less than 30 to 528 microM over the 3 h of infusion. Plasma leucine and KIC concentrations decreased by 65-70% (P less than 0.01) over the first 2 h of infusion. Leucine oxidation, estimated from the expired 14CO2 and the plasma [14C]KIC specific activity, as well as from an open two-pool model, decreased. By use of these isotope models, the rates of leucine coming from and going to protein decreased (P less than 0.05 to P less than 0.01). Interconversion of leucine and KIC estimated from the open two-pool model decreased by 80% (P less than 0.01). These changes were accompanied by a 36% decrease in the plasma concentration of total plasma amino acids. Within the confines of the isotope models employed, these data are consistent with the hypothesis that increased fatty acid oxidation decreases protein turnover and may spare essential amino acids.

Amino Acids↗
PubMed1985

Percutaneous radio frequency gangliolysis in the treatment of trigeminal neuralgia.

37 procedures were carried out in 32 patients with trigeminal neuralgia who were unrelieved by anticonvulsants. Initial relief was achieved in 31 patients (98%). 5 patients (16%) suffered a relapse during a follow-up period of 15-26 months. Corneal anaesthesia occurred in 6 patients, 1 of whom subsequently developed a corneal ulcer. Anaesthesia dolorosa appeared in 5 patients. Ipsilateral reduction in hearing was reported by 2 patients. Despite its limits and complications percutaneous radio frequency gangliolysis is an effective alternative in the treatment of trigeminal neuralgia.

Aged↗
PubMed1985

House dust control and asthma: a placebo-control trial of cleaning air filtration.

Using a placebo-control single-blind crossover trial, we investigated the effects of dust control measures alone and combined with electrostatic and high efficiency particulate air filters in the bedrooms of patients with asthma. Of 12 young asthmatics allergic to house dust and dust mite who entered the trial, nine completed all four 2-week intervals. No statistically significant improvement in symptom scores or peak expiratory flow above that recorded during the placebo interval occurred during any treatment phase. We conclude that house dust suppression adds little to the management of otherwise well controlled young asthmatic patients.

Air Pollution↗
PubMed1984

Reassessment of technical and biological factors in paranasal sinus carcinoma.

Twenty-seven patients with paranasal sinus carcinoma were analyzed. Local control with radiation alone was poor, with most patients failing centrally within the primary site. With preoperative radiation local control is 60%. Previous reports have emphasized failure at superior sites--particularly the orbit. The pattern of local failure in our series is predominantly various medial sites inclusive of intact or exenterated orbit. The surgically nonremovable medial structures are best encompassed by a three-field radiotherapy technique (weighted anterior and two laterals).

Adult↗
PubMed1984

Cardiac arrest following protamine administration.

A case report of fatal cardiac arrest following protamine reversal of systemic heparinization during vascular surgery is presented. Patients who have received protamine zinc insulin, NPH insulin, and those with previous exposure to protamine sulphate or allergy to fish are more likely to have a reaction to protamine. Protamine-induced hypotension can be mediated by immunological or non-immunological mechanisms. Several alternative methods of heparin reversal which may avoid similar catastrophes are presented.

Anaphylaxis↗
PubMed1984

New methodology in the raising of antibodies to small peptides leading to a highly specific radioimmunoassay for enkephalins.

Temporary chemical 'protection' of the amino and/or carboxyl termini of small peptides in conjugation reactions with high molecular weight carriers has provided immunogens which give rise to antibodies with high N-terminal and/or C-terminal specificity. Applied to [Leu]enkephalin, the new methodology resulted in antisera of high affinity (K eff 0.1 x 10(12) M-1) which recognized only enkephalin-like pentapeptides. The detailed residue specificity of one enkephalin antiserum is described.

Animals↗
PubMed1984

Changes in the concentration of somatostatin and substance P in the cerebrospinal fluid following injection of alcohol into the pituitary gland.

The concentration of immunoreactive somatostatin and Substance P in the cisternal cerebrospinal fluid (CSF) of patients with pain due to malignant disease has been measured before and after injection of alcohol into the pituitary fossa. Following the first injection, a rise of 108 +/- 66% in CSF somatostatin levels was observed in 7 out of 13 patients, and a rise of 87 +/- 26% in 4 out of the 5 patients undergoing a second injection. A rise of 179 +/- 99% in levels of Substance P in CSF was observed in 4 out of 8 patients after a single injection. No change in peptide concentration was detected in peripheral plasma. Changes in CSF levels did not correlate with the degree of pain relief obtained, but patients with the greatest increase in somatostatin subsequently developed diabetes insipidus. The data are consistent with our previous experience that injection of alcohol into the pituitary fossa can cause destruction to nervous tissue, in addition to the obvious destruction of pituitary gland tissue. They do not support the suggestion that hypothalamic damage is necessary in order to obtain pain relief.

Ethanol↗
PubMed1984

Chaotic motion of a weakly nonlinear, modulated oscillator.

A weakly nonlinear oscillator of natural frequency omega(0) and damping ratio delta is driven by an amplitude-modulated force of dimensionless amplitude epsilon, carrier frequency omega, and modulation frequency omega(1). Each of (omega - omega(0))/omega(0), omega(1)/omega(0), and delta is O(epsilon(2/3)) as epsilon --> 0. The response in this resonant neighborhood is a slowly modulated sine wave, the envelope of which is described by three first-order, autonomous, ordinary differential equations. This envelope, which is periodic for delta >> epsilon(2/3), is chaotic in certain ranges of (omega - omega(0))/omega(0) and omega(1)/omega(0) if delta/epsilon(2/3) is sufficiently small.

Journal Article↗