Evoked field potential analysis of dopaminergic mechanisms in the isolated turtle olfactory bulb

Dopaminergic mechanisms were Anatyzed in an isolated preparation of the turtle olfactory bulb. Field potentials were evoked by antidromic or orthodromic stimulation, and the effects determined of pharmacological manipulations of the bathing medium. In the presence of dopamine or a dopamine agonist, apomorphine, there was a reduction of amplitude and delay of onset of the component of the field potentials due to granule cell responses; fluphenazine, a dopamine antagonist, had generally opposite effects. Using paired volleys, it was found that the suppression of the response to the second test volley was reduced in the presence of dopamine or apomorphine, but enhanced in the presence of fluphenazine.The most likely explanation of these results is that exogenous dopamine depresses the response of mitral cells, which in turn decreases the dendrodendritic synaptic excitation of granule cells and reduces their inhibitory feedback onto mitral cells. This suggests that the dopaminergic cells in the bulb may suppress mitral cells by modulating excitable mechanisms in the mitral dendritic membrane, or modulating long-lasting synaptic potentials.     

Acute-phase proteins and the serological evaluation of experimental contact sensitivity in the mouse

The evaluation of contact reactions in previously sensitized mice is assessed conventionally by measurement of increases in ear thickness following challenge. In an attempt to develop a serological method for the investigation of contact sensitization in mice, we have examined whether analysis of changes in the concentration of acute-phase proteins in response to challenge provides a reliable alternative means of evaluating elicitation reactions. Measurement of either the relative serum haptoglobin concentration, using radial immunodiffusion, or the absolute concentration of serum amyloid A, by an enzyme-linked immunosorbent assay, has been found to correlate well with induced increases in ear thickness following challenge. Changes in the concentration of acute-phase proteins proved to be of sufficient sensitivity to reflect the specificity of contact sensitization and its inhibition by antigenic competition.     

Yeast-specific DNA probes and their application for the detection of Candida albicans.

Two DNA fragments cloned from the genome of Candida albicans ATCC 10261 may be useful in the rapid diagnosis of disseminated candidosis. One sequence (probe EOB1) was specific for C. albicans (positive hybridisation with 45 strains tested). The second sequence (probe EOB2) detected C. albicans, as well as five other pathogenic Candida spp. and Saccharomyces cerevisiae, but did not react with human or bacterial DNA. Both probes were repetitive sequences in the genome of C. albicans. Probe EOB1 was used to detect, without DNA amplification, 500 C. albicans yeast cells in 1 ml of human blood.     

Steady-state distribution of cycloleucine and alpha-aminoisobutyric acid between plasma and cerebrospinal fluid

Estimates of the steady-state distribution ratios of two nonmetabolizable amino acids, alpha-aminoisobutyric acid and aminocyclopentane carboxylic acid (cycloleucine), between plasma and cerebrospinal fluid were made with a view to establishing whether or not the low values found with metabolizable amino acids, such as glycine or leucine, could be accounted for by uptake and metabolism by the brain. The estimates, based on the ratios found after i.p. injections either in bolus form or by implantation of "osmotic pumps" containing the labeled amino acids, were comparable with those found for metabolizable amino acids.     

Metabolic syndrome screening using visceral adipose tissue (VAT) from opportunistic MRI locations in a multi-ethnic population

ObjectiveTo determine if visceral adipose tissue (VAT) area measured through MRI can be used opportunistically to assess the presence of cardiometabolic risk factors and compare its performance to simpler adiposity measures.MethodsA cross-sectional analysis was carried out on a subset of 1683 participants (856 women) from the Adiposity Phenotype Study (mean age = 69.2y; range 59.9–77.4). The association of total VAT area (sum of four cross sections, L1–L2, L2–L3, L3–L4, L4–L5) and each location, as well as BMI and body fat % (per SD) with the metabolic syndrome (MetSx) or its components was evaluated through logistic regression analysis.ResultsTotal VAT can be accurately predicted using all sites evaluated (R² range = 0.82?0.96). In men, VAT did not show a superior association to MetSx compared to BMI in men. However, in women, VAT was consistently superior to BMI and body fat % in its association to MetSx, independent of ethnicity [odds ratio for BMI, body fat %and total VAT area = 2.25 (95% CI: 1.93–2.62); 1.66 (95% CI: 1.36–2.03); 6.20 (95% CI: 4.69–8.21) respectively in all women]. Ethnic-specific odds ratios to MetSx in women ranged from 5.38 to 8.63 for total VAT area and 2.12–4.08 for BMI.ConclusionTotal VAT area can be accurately predicted from individual VAT regions in men and women and offers superior association to BMI for MetSx in women but not in men for five ethnicities. Therefore, opportunistic screening for elevated VAT area in women may be warranted across multiple ethnic groups.     

Criteria for intensive care unit admission and severity of illness

Intensive care is a specialist area of the hospital with concentration of resources and expertise to look after critically unwell patients. No set criteria exist for admission to intensive care, although patients usually have severe illness associated with physiological dysfunction and actual or impending organ failure. There are multiple scoring systems designed to assess severity of illness, all with significant limitations. The National Early Warning Score 2 (NEWS-2) is a commonly used ‘track and trigger’ system designed to detect and respond to the unwell or deteriorating patient. NEWS-2 is marker of physiological disturbance and high scores correlate with intensive care admission and mortality. Looking at the elective and emergency surgical population, patients at high risk of complications should be admitted to intensive care postoperatively. Increasing age, comorbidities, poor exercise tolerance and major surgical intervention are associated with adverse outcomes. Admission to intensive care often requires difficult time-critical decisions to be made with limited information. Intensive care admission can be the difference between life and death, but there are both physical and psychological harm associated with invasive organ support. The four pillars of medical ethics – autonomy, beneficence, non-maleficence and justice – can be used to guide these decisions.     

At what age should we attempt to retrieve sperm from males with Klinefelter syndrome

Klinefelter syndrome (KS) is a common disorder and almost every clinician in almost every sub-specialty of medicine will knowingly or unwittingly treat boys or men with a 47,XXY chromosomal constitution. Although there are numerous aspects of KS worthy of discussion, this contribution will focus specifically on the controversial, and as yet unresolved, issue of whether it is advantageous to harvest testis tissue from peri-pubertal or adolescent boys with KS in a heroic effort to preserve that child’s chances of reproduction in his future adult life. What would be the rationale for that, how does the biology of spermatogenesis in the Klinefelter testis impact that decision, and what does the data show? The answer, assembled from a selection of seemingly disparate sources and directions, appears to be “No”. We do not have to advocate for an aggressive approach, we do not have to preemptively preserve future fertility. We can justifiably wait until adulthood with equivalent chances of success.     

The formulary decision-making process in a health maintenance organisation setting

The goal of a health maintenance organisation (HMO) is to provide high quality, cost-effective healthcare services and products which meet the needs of the membership. Providing and managing pharmaceutical products and services within the HMO is a major aspect of accomplishing this goal. Several decisions must be made in developing, implementing and maintaining a formulary system. The numbers of people seeking their healthcare from HMOs in the US has increased 4-fold in 10 years, and several model types of HMOs have developed, including network HMOs, group HMOs, independent practitioner associations and staff models. HMOs utilising formulary systems provided cover to 76% of enrollees in 1992. Formulary system management and decision making entails the use of open vs closed formularies and the role of the pharmacy and therapeutics (P & T) committee. Product selection takes into account efficacy, safety, costs, patient acceptance, ease of use, dosage forms, preparation requirements, stability and storage requirements and the reputation of the manufacturer and the service it provides. We list and describe various policy decisions which HMO pharmaceutical decision makers must address if the formulary system is to become an efficient tool for the HMO.