Cytokine production by cryopreserved human peripheral blood mononuclear cells in response to periodontal pathogens.

Freezing techniques provide a way of repeating and extending immunological assays by using frozen portions of an individual's peripheral blood mononuclear cell fraction. Earlier work shows that the lymphocytes that are stored frozen retain their ability to respond to polyclonal B-cell activators, mitogens, superantigens and bacterial extracts of oral interest. These studies extend previous findings by determining cytokine production by lymphocytes following frozen storage for up to 24 weeks.

Interleukin-6 in neutrophils from peripheral blood and inflammatory periradicular tissues.

Periradicular tissue samples were recovered from patients undergoing endodontic surgery. Immunohistochemical procedures were used to identify interleukin-6 (IL-6) present in the neutrophils associated with these lesions. Using specific polyclonal antibody, 15 to 20% of the neutrophils associated with the periradicular tissue lesions were positive for IL-6.

Studies of proliferative responses by long-term-cryopreserved peripheral blood mononuclear cells to bacterial components associated with periodontitis.

Freezing techniques provide a means for repeating and extending immunological assays with frozen aliquots of an individual's peripheral blood mononuclear cell fraction. Lymphocytes which are stored frozen for a limited time retain their ability to respond to polyclonal B-cell activators, mitogens, and antigens of dental interest. Our studies extend these previous findings by determining lymphocyte functional activity following frozen storage for up to 100 weeks.

Changes in serum triiodothyronine kinetics and hepatic type I 5'-deiodinase activity of cold-exposed swine.

Swine exposed to cold air have elevated serum values of total triiodothyronine (TT3) and free T3 (FT3). To characterize the mechanism of these increases, we measured in vivo kinetic parameters after a bolus intravenous injection of 125I-labeled T3 by use of both multicompartmental (MC) and noncompartmental (NC) methods and in vitro hepatic type I iodothyronine 5'-deiodinase (5'D-I) activity. Ten ad libitum-fed 5-mo-old boars were divided into two groups, living for 25 days in either control (22 degrees C) or cold (4 degrees C) conditions.

Changes in triiodothyronine (T3) mononuclear leukocyte receptor kinetics after T3 administration and multiple cold-air exposures.

Repeated cold-air exposures increase human triiodothyronine (T3) plasma clearance rates. To study the response of the nuclear T3 receptor (NT3R) in this condition, binding characteristics were analyzed in human mononuclear leukocytes (MNL). In addition, we supplemented one group of individuals with a daily oral replacement dose of T3 to isolate the influence of serum thyroxine (T4) and thyrotropin (TSH) levels on receptor kinetics.

Relationship between changes in serum thyrotropin and total and lipoprotein cholesterol with prolonged Antarctic residence.

Antarctic residence (AR) is associated with a 50% increase in the thyrotropin (TSH) response to TSH-releasing hormone (TRH) and an expanded triiodothyronine (T3) distribution volume and extravascular hormone pool, collectively called the polar T3 syndrome. To investigate the possible biologic significance of this syndrome, we studied the relationship between nonstimulated TSH and serum lipid profiles in nine subjects, once while in California and monthly during 9 months of AR. We measured serum levels of TSH, total thyroxine (TT4), free T4 (FT4), total T3 (TT3), free T3 (FT3), thyroid-binding globulin (TBG), total cholesterol (T-CHOL), high-density lipoprotein cholesterol (HDL-C), triglyceride (TG), dietary cholesterol (D-CHOL), dietary fat (D-FAT), and dietary kilocalories at each month.

Multiple cold air exposures change oral triiodothyronine kinetics in normal men.

The influence of cold exposure on triiodothyronine (T3) kinetics was studied in 16 men before, during (biweekly), and after 80 (10/wk) cold (4 degrees C) air exposures. We used serum values before and up to 24 h after a pharmacological oral (o) dose of T3 [76.8 nmol (50 micrograms)] to calculate noncompartmental kinetic parameters.

Human cold air habituation is independent of thyroxine and thyrotropin.

Thyroxine (T4) is required in species possessing brown adipose tissue (BAT) for the maintenance of cold tolerance and adaptation. In humans, who possess negligible quantities of BAT, the importance of T4 has not been demonstrated. We studied the effects of decreased serum T4 and thyrotropin (TSH) on human cold habituation after repeated cold air exposures.

Radioprotection by polysaccharides alone and in combination with aminothiols.

We demonstrated that glucan, a beta-1,3 polysaccharide immunomodulator, enhances survival of mice when administered before radiation exposure. Glucan's prophylactic survival-enhancing effects are mediated by several mechanisms including (1) increasing macrophage-mediated resistance to potentially lethal postirradiation opportunistic infections, (2) increasing the D(o) of hematopoietic progenitor cells, and (3) accelerating hematopoietic reconstitution. In addition, even when administered shortly after some otherwise lethal doses of radiation, glucan increases survival.

Hematological parameters are altered during cold air exposure.

Whole blood hematocrit (HCT) decreases during multiple exposures to cold air. To better understand this finding, we have analyzed hematological profiles in 27 normal adult men exposed repeatedly to cold air in one of two experimental protocols. Experiment I was a cold air acclimatization study (CAA) conducted with two groups of 8 men in each group before, during, and after 80 separate 30-minute cold (4 degrees C) air exposures.

Propranolol fails to lower the increased blood pressure caused by cold air exposure.

Cold air exposure stimulates a rise in mean arterial blood pressure (MAP) and plasma norepinephrine (NE). The specific contribution of the beta-adrenergic receptor to this pressor response is unknown. Therefore, we pretreated 12 normal men with placebo or a bradycardia-inducing amount of propranolol prior to exposing them to either 25 degrees C or 4 degrees C air.

In vitro modulation of canine polymorphonuclear leukocyte function by granulocyte-macrophage colony stimulating factor.

Granulocyte-macrophage colony stimulating factor (GMCSF) promotes the growth of granulocytes and macrophages from undifferentiated bone marrow cells and modulates the oxidative responses of polymorphonuclear leukocytes (PMN) to endogenous chemoattractants. We found that, in vitro, naturally occurring glycolsylated human GMCSF does not disturb the resting canine PMN membrane potential, may attentuate PMN oxidative responses to PMA, and is, to a small degree, chemotaxigenic. GMCSF, however, inhibits PMN chemotaxis to zymosan-activated plasma (ZAP).

Decreased free fraction of thyroid hormones after prolonged Antarctic residence.

We investigated the effects of Antarctic residence (AR) on serum thyroid hormone and cardiovascular responses to a 60-min standard cold air (0 degree C) test (SCAT). Serum total thyroxine (TT4) and serum total triiodothyronine (TT3), free T4 (FT4) and T3 (FT3), thyrotropin (TSH), and percent free fraction of T4 (%FT4) and T3 (%FT3) were measured in normal men (n = 15) before and after each of three SCATs. The SCAT was first carried out in California and then repeated after 24 and 44 wk AR.

Quantitative and functional alterations of peripheral blood neutrophils after 10% and 30% thermal injury.

Polymorphonuclear leukocytes (PMNs) comprise the majority of early nonspecific inflammatory responses to infection or trauma and, as such, must be of sufficient number and qualitative function to properly limit and combat inflammation. Peripheral PMNs isolated from rats that received 10% or 30% body surface area full-thickness thermal injuries were quantitated and examined for functional alterations in membrane potential and cytosolic hydrogen peroxide production for 35 days after thermal injury. With 10% thermal injury, leukocytes increased quantitatively to experimental maximums that were 70% above normal on day 7 before a return to normal by day 28.

Hypermetabolic priming of canine neutrophils by 7-S nerve growth factor.

Canine circulating neutrophils, isolated by a blood lysing technique, were incubated with 7-S nerve growth factor (NGF), at final concentrations between 12.5 and 800 ng/ml, for 30 minutes at 37 C. Neutrophil cytosolic H2O2 production, measured by flow cytometry, after 7-S NGF incubation was not significantly different from that produced at 37 C (baseline temperature controls) alone.

Effects of collection methods and storage on the in vitro stability of canine plasma catecholamines.

Norepinephrine (NE) and epinephrine (EPI) collected from dogs were sequentially and temporally measured in blood and plasma at 24 C. Heparin and EDTA anticoagulants, in combination with reduced glutathione and EDTA as a preservative, were also compared. Norepinephrine and EPI concentrations were measured by high-pressure liquid chromatography with electrochemical detection.

In vitro effects of leukotriene B4 (LTB4) on canine PMN effector function(s).

The canine has become an accepted research model for the examination of a number of human clinical conditions. Despite it's status as a research model, little is known regarding the peripheral effects of inflammatory mediator substances. Products of arachidonic acid metabolism (leukotrienes) are reported capable of altering leukocyte functions.

Alteration of rat polymorphonuclear leukocyte function after thermal injury.

One portion of host defense to bacterial challenge(s) involves the activation and infiltration of endogenous polymorphonuclear leukocytes. Thermal injuries are frequently associated with immunologic abnormalities including alterations of polymorphonuclear leukocyte-associated nonspecific resistance. We examined isolated peripheral rat polymorphonuclear leukocytes for alterations in membrane potential, oxidative capability, and locomotor function after the experimental application of 20% full-thickness body surface area thermal injury.

Changes in canine neutrophil function(s) following cellular isolation by Percoll gradient centrifugation or isotonic lysis.

Analysis of cellular effector function(s) often requires their isolation from other cellular types. Cell separatory techniques could mask, or select out, clinically important functional lesions. We examined differences in canine peripheral blood neutrophil functions, i.

Glucan: mechanisms involved in its "radioprotective" effect.

It has generally been accepted that most biologically derived agents that are radioprotective in the hemopoietic-syndrome dose range (eg, endotoxin, Bacillus Calmette Guerin, Corynebacterium parvum, etc) exert their beneficial properties by enhancing hemopoietic recovery and hence, by regenerating the host's ability to resist life-threatening opportunistic infections. However, using glucan as a hemopoietic stimulant/radioprotectant, we have demonstrated that host resistance to opportunistic infection is enhanced in these mice even prior to the detection of significant hemopoietic regeneration. This early enhanced resistance to microbial invasion in glucan-treated irradiated mice could be correlated with enhanced and/or prolonged macrophage (but not granulocyte) function.