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M Aaron

Publications and source records attributed to M Aaron.

10 recordsLinked to original sources
PubMed2001

Diagnosing influenza: the value of clinical clues and laboratory tests.

OBJECTIVE: Our goal was to determine the utility of clinical clues, white blood cell (WBC) and differential counts, and a rapid antigen test for differentiating influenza from coexistent infectious diseases during influenza epidemics. STUDY DESIGN: Data were collected during 3 consecutive influenza outbreaks over a 2-year period. The information collected included date of onset, symptoms, vaccine status, WBC and differential counts, ZstatFlu test (ZymeTx, Oklahoma City, Ok), and influenza culture. Using culture positivity as the criterion for influenza diagnosis, we compared cases with noncases on each variable independently and by logistic regression. Receiver operating characteristic curves were plotted for WBC count, ZstatFlu, and their combination in an effort to determine the most useful diagnostic strategy. POPULATION: We included consecutive patients presenting to a family practice office with fever, cough, sore throat, myalgia, and/or headache during flu season. OUTCOMES MEASURED: The outcomes were sensitivity, specificity, and other measures of test accuracy. RESULTS: Culture-positive cases could not be reliably distinguished from those that were culture negative using symptoms or vaccination status. Both WBC count and ZstatFlu results discriminated fairly well, and their combination did somewhat better. Differential counts were not helpful. WBC counts above 8000 were associated with a low probability of influenza. The sensitivity and specificity of the ZstatFlu were 65% and 83%, respectively. CONCLUSIONS: Our data suggest that symptoms and vaccine status do not reliably identify patients with influenza. Use of WBC counts and the ZstatFlu test can be helpful. The sequence, combination, and criteria for use of these tests depend on tradeoffs between undertreatment of influenza cases and the overtreatment of noninfluenza cases, and the cost and benefit projections for individual patients.

Adult↗
PubMed2001

On access.

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Health Services Accessibility↗
PubMed1991

Human immunodeficiency virus glycoprotein (gp120) infused into rat brain induces interleukin 1 to elevate pituitary-adrenal activity and decrease peripheral cellular immune responses.

Intracerebroventricular (i.c.v.) infusion of glycosylated recombinant gp120, the envelope protein of human immunodeficiency virus, in various doses (100 ng to 4 micrograms) resulted in detection of interleukin 1 (IL-1) activity in a high percentage (61%; 33 of 54) of rat brains, whereas IL-1 was very rarely detected in brains of animals infused with several control substances (4%; 1 of 28). To detect IL-1, clarified glial lysate of diencephalon plus brainstem was subjected to gel exclusion chromatography and fractions were assessed for thymocyte stimulation. IL-1 was seen 2, 6, and 24 hr postinfusion. i.c.v. gp120 also produced known effects of IL-1 in brain, elevating steroid concentration in plasma and decreasing cellular immune responses [natural killer (NK) cell activity and mitogenic response to Con A] of blood and splenic lymphocytes. When gp120 was infused together with alpha-melanocyte-stimulating hormone (20 ng), which blocks many biological actions of IL-1, gp120 no longer elevated steroids or decreased NK cell activity. After intravenous gp120, IL-1 was not found in brain or plasma, indicating that stimulation of IL-1 in brain by i.c.v. gp120 was not due to gp120 affecting infiltrating cells from blood or to elevated circulating IL-1. That induction of IL-1 in brain might have resulted from lipopolysaccharide (LPS) in the gp120 solution was ruled out by studies showing that (i) heating of the infusion solution, which does not affect the capacity of LPS to induce IL-1, eliminated the ability of gp120 infusion to induce brain IL-1, and (ii) gp120 induced IL-1 in brains of LPS-resistant C3H/HeJ mice. Injection of gp120 directly into the hippocampus stimulated IL-1 more readily than i.c.v. infusion. Thymocyte stimulation produced by active fractions of gp120-infused brains was blocked by monoclonal antibody to IL-1 receptors. These findings indicate that elevation of IL-1 in brain can result from infection with human immunodeficiency virus and may be responsible for certain abnormalities (e.g., elevated activity of pituitary-adrenal axis) seen in AIDS patients.

Animals↗
PubMed1988

Splanchnic amino acid and glucose metabolism during amino acid infusion in dogs.

With the organ-balance technique, we studied amino acid and glucose metabolism by hepatic and extrahepatic splanchnic tissues in awake dogs in the postabsorptive state and during a 3-h intravenous amino acid infusion. Dogs received a high (1.4 g/kg body wt, n = 5) or low (0.7 g/kg body wt, n = 8) dose of amino acids. In four of the latter dogs, the dose was delivered into a mesenteric vein. During the basal period there was a net removal of gluconeogenic amino acids (particularly alanine), but not branched-chain amino acids, and a net production of glucose by the liver in all dogs. During this time there was a net removal of glucose and production of alanine by the extrahepatic splanchnic tissues. During either high- or low-dose amino acid infusion, net hepatic glucose release increased; despite this, arterial plasma glucose declined due to an increase in tissue glucose uptake at extrasplanchnic sites. The net amount of glucogenic amino acids removed by the liver during high-dose (9.1 +/- 1.0 mmol.kg-1.3 h-1) and low-dose (4.8 +/- 0.6 mmol.kg-1.3 h-1) infusion equaled or exceeded the infused load of these amino acids. In addition, the liver contributed to the net disposal of branched-chain amino acids during high-dose (536 +/- 147 mumol.kg-1.3 h-1) and low-dose (341 +/- 70 mumol.kg-1.3 h-1) infusion. During high-dose infusion, extrahepatic splanchnic tissues participated in the net removal of branched-chain amino acids (436 +/- 162 mumol.kg-1.3 h-1) but not glucogenic amino acids, and net alanine production continued (410 +/- 91 mumol.kg-1.3 h-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1975

Omission training and extinction in rats with septal damage.

Rats with either control operations or septal damage were pretrained on a VI 30-sec schedule and tested for response suppression ability on either an omission training (OT) task or on extinction. Septal damage enhanced barpressing on the VI 30-sec task. Animals with septal damage took longer to suppress responding on the OT task than controls while lesioned and control animals tested on extinction did not differ. Increased emotionality was seen in subjects with septal damage on the first test day but not thereafter. Animals tested with OT suppressed responding more rapidly than animals tested on extinction.

Animals↗