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Biomedical subjects

J Barron

Publications and source records attributed to J Barron.

At least 37 records · Page 2Linked to original sources
PubMed1994

Finger sudorometry and assessment of the sudomotor drive.

Sudorometry of the finger was carried out using the ventilated capsule method, the aim being to use the level of relative humidity within the sudorometer as an indirect measure of the sudomotor drive. Subjects inserted a finger through a diaphragm of a finger-shaped, temperature-controlled chamber which also contained the humidity sensor. Manoeuvres known to alter the sudomotor drive produced changes in chamber humidity. The relative humidity within the sudorometer became constant after local anaesthesia of the digital nerves and after upper limb sympathectomy, suggesting that fluctuations in the sudorometer output were dependent upon an intact autonomic nervous system. In an environment in which temperature was controlled and arousal effects from the process of measurement were minimised, chamber humidity always increased during a Stroop test, providing a rapid means of indirectly assessing sudomotor drive mechanisms.

Anesthesia, Local↗
PubMed1994

Ultrasonographic evaluation of central and end-organ hemodynamics in antepartum pyelonephritis.

OBJECTIVE: Our purpose was to evaluate central and end-organ hemodynamic effects of antepartum pyelonephritis. STUDY DESIGN: Daily duplex ultrasonographic assessments of maternal cardiac output and resistive index values of the maternal renal and uterine arteries and the fetal umbilical arteries were performed in pregnant women admitted for acute pyelonephritis. For comparison, the same measures were repeated within 2 weeks after discharge. RESULTS: Thirty-seven women with antepartum pyelonephritis underwent serial 2-dimensional real-time and Doppler evaluation of maternal heart and duplex Doppler evaluation of maternal renal and uterine and fetal umbilical arteries. Significant differences in temperature, mean arterial pressure, and heart rate were observed during hospitalization compared with the follow-up visit. Total peripheral resistance was significantly decreased and cardiac output increased during acute infection. In women with unilateral signs and symptoms an increased resistive index was observed in the symptomatic kidney compared with the nonsymptomatic side; this difference disappeared on the follow-up study. No changes were observed in maternal uterine or fetal umbilical arteries. CONCLUSIONS: Uncomplicated pyelonephritis is associated with measurable depression of systemic vascular resistance. This likely represents an effect of infection that in the extreme would be the septic shock syndrome. It seems reasonable to attribute the increased resistive index of the symptomatic kidney to local effects of infection.

Acute Disease↗
PubMed1989

The use of quantitative bacterial counts in open fractures.

Late infections remain a significant complication in the treatment of open fractures, occurring in 2% to 25% of all open fractures. Recently there has been a trend toward early soft-tissue coverage of open fracture wounds. Quantitative bacterial counts have been used primarily by plastic surgeons to assess the viability of primary versus delayed wound closures. Quantitative bacterial counts were obtained in 52 consecutive open fractures in 50 patients to assess the correlation between quantitative bacterial counts and subsequent sepsis, to determine the effect of time to debridement on the quantitative bacterial count, and finally to review the bacteriology of open fractures. Forty-one of the 52 fractures had positive quantitative bacterial counts. Four of eight (50%) fractures with quantitative bacterial counts greater than 10(5) developed late sepsis, while only two of 44 (5%) with quantitative bacterial counts less than 10(5) or negative quantitative counts became infected. There was no correlation between time to debridement and quantitative bacterial count levels. A significant percentage of the positive quantitative bacterial counts were gram-negative organisms.

Adult↗
PubMed1989

Prosthetic usage following major lower extremity amputation.

There were 157 patients following major lower extremity amputation who were evaluated to determine functional prosthetic ambulation. Twenty-eight patients were evaluated in the amputee clinic and found not to be candidates for prosthetic fitting. Forty-one patients were fit with a prosthesis but did not become functional prosthetic ambulators. Eighty-eight patients became functional prosthetic ambulators. Of all above-the-knee amputees, 46% became functional prosthetic ambulators. Only 19% of bilateral lower extremity amputees became functional prosthetic ambulators. Of all below-the-knee amputees, 66% became functional ambulators. The presence of coronary artery disease decreased the ambulatory potential in above-the-knee or bilateral amputees but not in below-the-knee amputees. A screening method for elderly, dysvascular amputees should be instituted prior to prosthetic fitting.

Aged↗
PubMed1987

The incidence and causes of hypercalcaemia.

A prospective screen for hypercalcaemia in 58,053 hospital in-patients was conducted over 12 months. The incidence of hypercalcaemia was 0.6%, being transient in 19.2% of patients and sustained in the remainder. The most common causes in the sustained group were malignancy (45%) and primary hyperparathyroidism (16.5%). The incidence of primary hyperparathyroidism was 78/100,000 hospital in-patients, and its discovery was directly attributable to the survey in over half the cases.

Adult↗
PubMed1985

Paradoxical excitement to sedative-hypnotics in mentally retarded clients.

The relationships among "paradoxical" excitement to sedative--hypnotic medication, self-injurious behavior, and perinatal trauma were evaluated. Mentally retarded patients were classified as either paradoxical or normal responders to sedative-hypnotics. Paradoxical responders to these medications have a lower MA, a history of perinatal trauma, self-injurious behavior (SIB), and aggressive behavior when compared to normal responders. These findings confirmed and extended previous reports that a type of SIB may be indexed by paradoxical response to sedative-hypnotics. Results also suggested that perinatal trauma may be of etiological importance in the development of SIB. Because perinatal trauma or fetal distress results in excessive levels of B-endorphin, in utero, an impaired endogenous opiate system may be a critical factor maintaining a syndrome of SIB. Thus, these data may indicate psychopharmacological markers of SIB that may have both treatment and etiological significance.

Adolescent↗
PubMed1985

Effect of heat treatment on results for biochemical analysis of plasma and serum.

Incubation of serum and plasma samples at 56 degrees C for 30 min inactivates the HTLV-III virus. We assessed the effect of this procedure on results of routine biochemical tests by dividing samples of serum and plasma into two, heat-treating one while the other remained at room temperature. Samples were then analyzed in an SMA 16/60, an Astra-8, an Analox glucose analyzer, a Cobas Bio centrifugal analyzer, and manually for salicylate and acetaminophen (paracetamol). Most of the differences produced by heat treatment were not clinically significant, although heated samples proved unsuitable for use in assay of some commonly measured enzymes. Serum evidently is preferable to plasma for this procedure, and heat-treated serum samples can validly be used for most routine analyses. Thus this procedure makes safer the analysis of samples from patients with suspected or proven acquired immune deficiency syndrome (AIDS).

Acquired Immunodeficiency Syndrome↗
PubMed1983

Synaptic development and microtubule organization.

Using techniques for enhanced microtubular preservation (albumin pretreatment of Gray) occipital and pyriform cortices of rats were studied by electron microscopy at various stages of development. A close structural relationship was seen between microtubules (mts), focal membrane densities, synaptic vesicles, and presynaptic dense projections (pre-dps) during maturation. Mts were seen in the neonates to be focused onto the inner surface of immature axonic profiles merging or sometimes fragmenting there. Focal densities occur at these attachment sites and thereafter synaptic vesicles clothe the mts and abut onto these presumed primordial pre-dps. Thus, mts may contribute to the initial formation of pre-dps as well as their maintenance in the adult and may act to channel the first synaptic vesicles to the site of eventual synaptic contact and transmitter release.

Aging↗
PubMed1983

Cytochemical localisation of calcium binding sites in adrenal chromaffin cells and their relation to secretion.

The ultrastructural localisation of calcium in the chromaffin cells of the adrenal medulla was investigated using the pyroantimonate technique. The electron-dense precipitate resulting from processing in the presence of pyroantimonate was removed by treatment of sections with 2 mM EGTA suggesting that the pyroantimonate technique was localising calcium since this chelator shows a 1000:1 preference for Ca2+ over Mg2+. Using dissociated cells from the bovine adrenal medulla, calcium was localised in control cells and in cells stimulated with 1 mM carbamylcholine for 1, 10 and 30 min. Stimulation resulted in an increase in plasma membrane-associated calcium within 1 min. Much of this calcium was localised at sites of granule-plasma membrane interaction and was also seen at sites of coated-vesicle formation at longer periods of stimulation. Membrane-bounded vacuoles, appearing in cells stimulated for 10 or 30 min, also showed associated electron-dense precipitate. The results obtained are consistent with a role for the calcium ion as a mediator in exocytosis at the stage of granule-plasma membrane fusion.

Adrenal Medulla↗
PubMed1983

Naloxone attenuates self-abusive behavior in developmentally disabled clients.

The opiate antagonist naloxone was effective in reducing self-abusive behavior in two mentally retarded clients with an extensive history of such behavior. Three doses of naloxone (0.1, 0.2, 0.4 mg) were compared with a vehicle solution in a double-blind, crossover design. Naloxone greatly attenuated self-abusive episodes in one client and eliminated them entirely in the second client. In addition, use of self-restraining behavior by one client was reduced. The findings suggested that some clients with self-injurious behavior may have disturbances of the endogenous opiate system. Maintenance of self-abuse by tonically elevated pain threshold and/or by the putative addictive characteristics of such behavior was discussed.

Adult↗
PubMed1983

Relationship of sedative-hypnotic response to self-injurious behavior and stereotypy by mentally retarded clients.

Groups of clients exhibiting both self-injurious behavior (SIB) and stereotypy, stereotypy alone, SIB alone, or neither of these types of behavior were rated in terms of response to sedative-hypnotic medication. Sixty-eight percent of the clients with both SIB and stereotypy maintained wakefulness and were either resistive, combative, restless, uncooperative, or abusive after treatment with sedative-hypnotics. Thirty-nine percent of the clients with only SIB and 35 percent of the clients with only stereotypy evidenced such "paradoxical" responses to these medications. None of the matched control clients displayed paradoxical responses. This result suggests that an impaired endogenous opiate system characterized by increased levels of beta-endorphin may mediate and maintain a type of syndrome of SIB that involves the presence of stereotypy, implying the need for a new diagnostic classification and treatment of these aberrant behavioral disorders.

Adolescent↗
PubMed1983

Cystic hamartoma of the lung.

A patient with a rare cystic hamartoma of the lung had diagnoses of tuberculosis, bronchiectasis, pneumonia, and neoplasm during the 23 years prior to resection of the lesion. The hamartoma had vascular elements which led to intermittent hemoptysis and, finally, to gross hemorrhage into the lung.

Hamartoma↗