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Biomedical subjects

S L Jones

Publications and source records attributed to S L Jones.

At least 127 records · Page 7Linked to original sources
PubMed1991

Descending noradrenergic influences on pain.

Multiple separate and distinct supraspinally organized descending inhibitory systems have been identified which are capable of powerfully modulating spinal nociceptive transmission. Until recently, brainstem sites known to be involved in the centrifugal modulation of spinal nociceptive transmission were few in number, being limited to midline structures in the midbrain and medulla (e.g., periaqueductal gray and nucleus raphe magnus). However, with continued investigation, that number has increased and brainstem sites previously thought to be primarily involved in cardiovascular function and autonomic regulation (e.g., nucleus tractus solitarius; locus coeruleus/subcoeruleus (LC/SC); A5 cell group; lateral reticular nucleus) also have been demonstrated to play a role in the modulation of spinal nociceptive transmission. Spinal monoamines (norepinephrine (NE) and serotonin) have been shown to mediate stimulation-produced descending inhibition of nociceptive transmission from these brainstem sites. The majority of NE-containing fibers and terminations in the spinal cord arise from supraspinal sources; thus, the LC/SC, the parabrachial nuclei, the Kölliker-Fuse nucleus and the A5 cell group have all been suggested as possible sources of the spinal noradrenergic (NA) innervation involved in the centrifugal modulation of spinal nociceptive transmission. Several lines of evidence suggest that the LC/SC plays a significant role in a functionally important descending inhibitory NA system. Focal electrical stimulation in the LC produces an antinociception and increases significantly the spinal content of NA metabolites. The inhibition of the nociceptive tail-flick withdrawal reflex produced by electrical stimulation in the LC/SC has been demonstrated to be mediated by postsynaptic alpha 2-adrenoceptors in the lumbar spinal cord. Similarly, electrical or chemical stimulation given in the LC/SC inhibits noxious-evoked dorsal horn neuronal activity. Thus, results reported in electrophysiological experiments confirm those reported in functional studies and the NA coeruleospinal system appears to play a significant role in spinal nociceptive processing.

Adrenergic Fibers↗
PubMed1991

Specificity of antibodies present in human periapical lesions.

Various classes of immunoglobulins have been found in human periapical lesions. The specificity of secreted antibodies against antigens egressing from the root canal system has yet to be thoroughly investigated. The purpose of this study was to test the specificity of antibodies present in human periapical lesions. Human periapical biopsies were removed and cultured as organ culture explants. Antibodies present in the lesions were extracted in the cell culture fluids. A modified enzyme-linked immunosorbent assay was used to determine the presence, type, and concentration of different classes of antibodies against a number of commonly found bacterial species present in the root canal system. The data show the presence of specific antibodies (IgG, IgM, and IgA) against all 16 microorganisms tested. Peptostreptococcus micros, Actinomyces israelii, Staphylococcus intermedius, and Fusobacterium nucleatum produced significantly high levels of IgG antibodies in these lesions.

Actinomyces↗
PubMed1991

Development and evaluation of a rapid absorbed enzyme immunoassay test for the diagnosis of Johne's disease in cattle.

An absorbed enzyme immunoassay (EIA) test for Johne's disease in cattle was developed in which absorption of cross-reacting antibodies occurred as a rapid reaction in solution rather than overnight with whole organisms and a subsequent centrifugation step. Total test time was reduced to less than 2 h with a minimum of manipulations. The test was evaluated in cattle herds from Johne's disease-endemic and Johne's disease-free regions of Australia. Specificity was 99.8%. Calculations of sensitivity were affected by the history of the herd under test. However, the EIA detected in excess of 80% of animals before onset of clinical disease and 65% of faecal shedders were EIA positive on, or before, first detection of Mycobacterium paratuberculosis in their faeces. The test should aid epidemiological studies and be a useful tool in the management and control of Johne's disease.

Absorption↗
PubMed1991

Field comparison of the interferon-gamma assay and the intradermal tuberculin test for the diagnosis of bovine tuberculosis.

An extensive field comparison of the gamma interferon (IFN-gamma) assay and the single intradermal tuberculin test for the diagnosis of bovine tuberculosis was conducted in Australia. The specificity of the IFN-gamma assay was determined by testing more than 6000 cattle from tuberculosis-free herds and varied from 96.2% to 98.1%, depending on the cut-off point chosen to define a positive reactor. For the sensitivity trial, cattle from herds being de-populated because of bovine tuberculosis were examined with both assays. The sensitivity of the IFN-gamma assay was shown to be significantly higher than the single intradermal tuberculin test and varied from 76.8% to 93.6% depending on the method of interpretation. A maximum overall sensitivity of 95.2% was obtained by testing with the IFN-gamma and the tuberculin test in parallel. The superior sensitivity of the IFN-gamma assay and the ability to adjust the sensitivity of the system depending on the task involved, will provide the Australian Tuberculosis Eradication Campaign with a valuable additional test to enable it to accomplish its goals.

Animals↗
PubMed1990

Effects of iontophoresed opioids on physiologically characterized laminae I and II dorsal horn neurons in the cat spinal cord.

The objective of the present study was to determine in vivo the effects of opioids applied locally via microiontophoresis on physiologically characterized laminae I and II dorsal horn neurons in the cat spinal cord. Experiments were performed on pentobarbital-anesthetized or decerebrate, spinalized cats. The effects of morphine (MOR), [D-Ala2,methyl-Phe4, Gly-ol5]enkephalin (DAGO) and naloxone (NALO) on spontaneous- and D,L-homocysteic acid-evoked unit activity were examined for 94 laminae I and II dorsal horn neurons. MOR, DAGO and NALO produced mixed effects (i.e., excitation or inhibition) on unit activity; however, the majority of cells examined (67%) were inhibited. Whether MOR, DAGO or NALO exerted excitatory or inhibitory influences on unit activity did not depend on the modality of the neuron (66% of high threshold units, 56% of multireceptive units and 69% of low threshold units were inhibited; some cells of each modality also were excited). NALO also was found rarely to be neutral; 75% of the cells examined were inhibited and 16% excited by NALO. Since NALO was found to itself have significant effects on laminae I and II dorsal horn unit activity, the ability to use NALO as an opioid antagonist to MOR and DAGO was confounded.

Animals↗
PubMed1990

Electrical stimulation in the medullary nucleus raphe magnus inhibits noxious heat-evoked fos protein-like immunoreactivity in the rat lumbar spinal cord.

Noxious heat applied to the footpad evokes the expression of fos protein-like immunoreactivity in the rat spinal cord lumbar dorsal horn. Electrical stimulation in the medullary nucleus raphe magnus (NRM) while not evoking fos-like immunoreactivity itself, reduced significantly the number of neurons (to 50% of control) in the dorsal horn demonstrating fos protein-like immunoreactivity in response to noxious heating of the footpad. Thus descending projections from the medullary NRM appear to have direct inhibitory effects on dorsal horn neurons that receive nociceptive input from cutaneous thermal nociceptors.

Animals↗
PubMed1990

Termination patterns of serotoninergic medullary raphespinal fibers in the rat lumbar spinal cord: an anterograde immunohistochemical study.

Electrical and chemical stimulation given in the ventral medullary raphe nuclei inhibits spinal nociceptive reflexes and spinal nociceptive transmission; serotoninergic receptors have been demonstrated to partially mediate that inhibition. In the present study, the termination patterns of raphespinal fibers in the rat lumbar spinal cord demonstrating serotonin-like immunoreactivity were examined by using the anterograde tracer Phaseolus vulgaris leucoagglutinin (PHA-L) in combination with immunohistochemistry. Fibers and terminations from the ventral medullary raphe nuclei (raphe magnus and raphe pallidus) demonstrating both PHA-L- and serotonin-like immunoreactivity were identified in all laminae of the dorsal horn and the ventral horn. Networks of large fibers, characterized by large boutons, and which did not demonstrate serotonin-like immunoreactivity, were identified in deeper laminae of the dorsal horn. The heterogeneous morphology of raphespinal fibers identified in the dorsal horn suggests that these fibers also may be heterogeneous in neurochemistry and function. Medial medullary sites outside the raphe nuclei were found to innervate the ventral horn and all laminae of the dorsal horn, with the exception of lamina I. Descending fibers and terminations also demonstrating serotonin-like immunoreactivity were identified in deep laminae (III, IV, V, VI) of the dorsal horn and in the ventral horn. Similarly, large fiber networks were identified which did not demonstrate serotonin-like immunoreactivity.

Animals↗
PubMed1990

Increased monoclonal antibody ascites production in mice primed with Freund's incomplete adjuvant.

The production of monoclonal antibodies is conveniently achieved by propagation of antibody-secreting hybridoma cells as ascites tumours in mice. With a view to improve production and minimise animal usage, the choice of primer (pristane or Freund's incomplete adjuvant (FIA] and the effect of sex of mouse (female vs. uncastrated male) upon antibody yields were compared. The volume of ascitic fluid harvested from 134 FIA-primed mice was 697 ml, which was significantly (P less than 0.02) greater than the 343 ml collected from 116 pristane-primed mice. Moreover, FIA-primed mice required tapping for only 11 days (90% in 7 days) compared to the 17 days needed for pristane-primed mice. While there was little difference between the mean IgG1 concentration (as determined by enzyme immunoassay) of both ascites pools (4.9 mg/ml compared to 4.6 mg/ml), the volume differences equated to yields of 25.5 mg/mouse and 13.5 mg/mouse respectively. The FIA-primed mice were also shown to produce on average more (P less than 0.02) ascites per day. There was no significant difference found between the yield of monoclonal antibodies obtained from either uncastrated males (22.1 mg/mouse) or females (23.1 mg/mouse). The use of FIA to prime mice for the in vivo production of monoclonal antibodies should improve the yield to over 20 mg/mouse, thereby reducing the number of mice required.

Animals↗
PubMed1990

Transvaginal chorionic villus sampling.

Chorionic villus sampling (CVS) with either transcervical catheters or transabdominal needles is a widely-accepted method for prenatal diagnosis. However, there exists a small subset of patients in whom sampling is difficult or impossible with either route because of individual anatomic variations. A new method of chorionic villus biopsy has been developed to circumvent these problems, utilizing transvaginal chorionic needle aspiration guided by an intravaginal ultrasound probe. This technique was performed successfully in 15 patients in whom villi could not be obtained by either of the conventional methods. This method now makes CVS possible in essentially all women regardless of their uterine anatomy or placental placement; it may also prove useful for very early chorionic sampling.

Adult↗
PubMed1990

Production and characterization of monoclonal antibodies specific for bovine gamma-interferon.

Nine stable hybridoma cell lines were established which secreted specific monoclonal antibodies (MAbs) to bovine gamma-interferon (BoIFN-gamma). Specific binding of each of the MAbs to recombinant BoIFN-gamma (rBoIFN-gamma) was demonstrated in an indirect ELISA, whilst none of the MAbs bound to rBoIFN-alpha or rBoIFN-beta. In a Western blot the MAbs reacted with the 16 kDa and 32 kDa polypeptides present in rBoIFN-gamma preparations. Competitive ELISA's showed that four MAbs bound to one epitope on rBoIFN-gamma, and the other five MAbs bound to a separate epitope. Two MAbs, each recognising different epitopes, were shown to neutralise the anti-viral activity of natural BoIFN-gamma.

Animals↗
PubMed1990

A randomized trial to improve compliance in urinary tract infection patients in the emergency department.

A randomized trial was used to evaluate two forms of a health belief model (HBM) intervention aimed at increasing compliance among 139 patients with urinary tract infections who presented to the emergency department. Patients who received an HBM clinical intervention administered in the ED, HBM telephone intervention two to four days after the ED visit, or both interventions were much more likely than control patients to both schedule and keep a follow-up referral appointment. Both the clinical and telephone interventions were designed to increase perceived susceptibility to complications of the urinary tract infection, seriousness of the complications, and benefits and costs of action. Other factors predicting compliance include age of the patient, urgency of the urinary tract infection as rated subjectively by the emergency physician, need for child care, whether transportation was available, and questioning the nurse about the referral appointment.

Acute Disease↗
PubMed1990

Cardiovascular screening in Army personnel over age 40 in the State of Hawaii.

A cardiovascular screening protocol was applied prospectively to 1,900 soldiers over 40 years of age to identify individuals with latent coronary artery disease. Primary screening included a cardiovascular history, physical examination, electrocardiogram, serum cholesterol and serum glucose determinations, and calculated Framingham risk index. Seven hundred ninety-six individuals required secondary screening, consisting of stress testing and cardiac fluoroscopy. The screening process led to coronary angiography in 43 individuals; of these, 17 had obstructive coronary artery disease, ten had nonobstructive coronary artery disease, and 16 had normal coronary arteries. Application of primary screening before exercise testing increased the posttest probability of obstructive coronary artery disease to 50% in the individuals with a positive treadmill test. This is four times the expected value of 11% calculated using Bayes' theorem. The combination of a positive treadmill test and the finding of coronary artery calcification on fluoroscopy was an excellent predictor of obstructive coronary artery disease.

Adult↗