The effect of glycerol and desmopressin on exercise performance and hydration in triathletes

Previous work from this laboratory has demonstrated an association between the suppression of c-myc expression and the antiproliferative activity of both topoisomerase II inhibitors and ionizing radiation in MCF-7 breast tumor cells. These findings suggested that suppression of c-myc expression could be related to the induction of DNA damage in this cell line. The present studies were designed to determine whether the inhibition of topoisomerase I (and the consequent induction of DNA strand breaks) would also result in the suppression of c-myc expression. At camptothecin concentrations of 1 microM and below, there was no detectable damage (single- or double-strand breaks) in bulk DNA or suppression of c-myc expression. At camptothecin concentrations of 5, 10, and 25 microM, where suppression of c-myc expression was observed, strand breaks in bulk DNA were also detected. These findings are consistent with the idea that suppression of c-myc expression could be a component of the DNA damage response pathway in MCF-7 breast tumor cells. In contrast to the absence of detectable damage to bulk DNA or suppression of c-myc expression at the lower concentrations of camptothecin, DNA synthesis was inhibited over the entire range of drug concentrations and demonstrated a strong correspondence with growth inhibition. These observations support the concept that growth inhibition of MCF-7 cells by camptothecin is closely related to the early suppression of DNA synthesis.     

Epstein-Barr virus induces GM-CSF synthesis by monocytes: effect on EBV-induced IL-1 and IL-1 receptor antagonist production in neutrophils

Neutrophils play an important role in the control of viral infections by releasing a variety of potent agents. We previously demonstrated that Epstein-Barr virus (EBV) binds to human neutrophils and stimulates cytokine synthesis including interleukin-1 (IL-1) and IL-1 receptor antagonist (IL-1Ra). Since neutrophil functions are known to be modulated by the priming effect of granulocyte-macrophage colony-stimulating factor (GM-CSF), we therefore investigated the cellular source of GM-CSF synthesis following treatment of leukocytes with EBV and the effect of GM-CSF on the production of IL-1, IL-1Ra, and superoxide by EBV-treated neutrophils. In enriched-cell populations, only monocytes were found to produce GM-CSF in response to EBV, which was maximal after 12 h of incubation. The results obtained with UV-irradiated particles or EBV neutralized with monoclonal antibody 72A1 suggest that contact between the cell and the gp350 of the viral envelope is sufficient to induce the release of GM-CSF. On the other hand, GM-CSF differentially upregulated EBV-induced IL-1 and IL-1Ra production by neutrophils. Pretreatment of neutrophils with GM-CSF prior to EBV activation synergistically enhanced the production of IL-1 alpha and IL-1 beta, but only marginally affected IL-1Ra synthesis. In addition, GM-CSF was also found to synergistically enhance the superoxide production by neutrophils in response to EBV. Molecular analysis showed that GM-CSF did not alter the IL-1 beta and IL-1Ra mRNA synthesis induced by EBV, suggesting that GM-CSF could act at a posttranslational level. Local production of GM-CSF by monocytes in tissues invaded by EBV could serve to potentiate the host defense mechanisms directed toward the destruction of the infectious virus.     

The effect of heavy metals on neutrophils

The influences of some heavy metals i.e. of mercury, zinc, copper, manganese, nickel and cobalt on metabolic activity and functional states of human neutrophils were presented. Simultaneously the pathomechanisms of the observed disturbances were described.     

Interferon-gamma and interleukin-4 reciprocally regulate the production of monocytes/macrophages and neutrophils through a direct effect on committed monopotential bone marrow progenitor cells

We studied the direct effects of interferon-gamma (IFN-gamma) in single cell colony assays of CD34+HLA-DR++ bone marrow progenitor cells stimulated by either granulocyte-colony-stimulating factor (G-CSF), interleukin(IL)-3, granulocyte/macrophage-colony-stimulating factor (GM-CSF), combinations of these CSF or medium conditioned by the 5637 human bladder carcinoma cell line. In this culture system IFN-gamma stimulated monocytic colonies (CFU-M) no matter which CSF or CSF combination was used to support them and inhibited granulocytic colonies (CFU-G) if they were generated in the presence of G-CSF. IL-4 antagonized the myelopoietic effects of IFN-gamma: the IFN-gamma-induced suppression of G-CSF-supported CFU-G, as well as the stimulation of CFU-M, were reversed by IL-4. In all cultures, IFN-gamma had a limited, but statistically non-significant, inhibitory effect on CFU-GM, which was not affected by the presence of IL-4. These data show that IFN-gamma and IL-4 reciprocally regulate the generation of myeloid cells involved in humoral (neutrophils) and cellular (macrophages) immune responses through a direct effect on monopotential myeloid progenitor cells.     

Beneficial effect of intranasal desmopressin for nocturnal polyuria in Parkinson's disease

Patients with Parkinson's disease (PD) are known to experience autonomic nervous system dysfunction: this disruptive symptomatology includes urinary urgency, frequency, and nocturnal polyuria. Anticholinergic and tricyclic medications can be beneficial in controlling these urinary symptoms, but have unpleasant side effects in some patients. Desmopressin has been used to treat nocturnal polyuria successfully in a number of conditions, such as central diabetes insipidus, enuresis, and autonomic failure. The purpose of the present study was to assess the efficacy of desmopressin in patients with PD with significant nocturia. Eight patients were recruited into the study. They were first asked to establish a baseline of number of nocturnal voids; the patients were then prescribed the intranasal form of desmopressin and asked to continue to record the number of nocturnal voids. The five patients who completed the trial demonstrated clinically and statistically significant reductions in the frequency of nocturnal voids. One patient became hyponatremic and confused during desmopressin administration; his symptoms resolved soon after the desmopressin was discontinued. Two patients failed to complete the trial due to compliance problems. Thus, desmopressin appears to be a safe and effective medication for nocturnal polyuria in PD.     

Reduction of acyloxyacyl hydrolase activity in circulating neutrophils from cows after parturition

Bovine neutrophils contain the enzyme acyloxyacyl hydrolase, which hydrolyzes the acyloxyacyl linkage of the two nonhydroxylated fatty acyl chains to two 3-hydroxy fatty acids in the highly conserved lipid A part of endotoxins with high specificity. This hydrolysis decreases the toxicity of lipid A, but the immunostimulatory capacity of endotoxins is largely maintained. In two trials, we studied the activity of acyloxyacyl hydrolase in neutrophils that had been isolated from the blood of 18 dairy cows around parturition. Between 10 and 26 d after parturition, the activity of acyloxyacyl hydrolase in neutrophils decreased approximately 20% below prepartum activity. At about 2 mo after parturition, acyloxyacyl hydrolase activity returned to prepartum values. Changes in acyloxyacyl hydrolase activity could not be attributed to changes in binding of lipopolysaccharides by the CD14 molecules on neutrophils or monocytes. We hypothesize that decreased acyloxyacyl hydrolase activity in neutrophils shortly after parturition is a factor that increases the susceptibility of dairy cows to coliform mastitis during early lactation.     

Ligation of CD31/PECAM-1 modulates the function of lymphocytes, monocytes and neutrophils

CD31 or platelet/endothelial cell adhesion molecule (PECAM-1) is a 130-kDa glycoprotein expressed on endothelial cells, granulocytes, a subset of lymphocytes and platelets. In this study, we examined the ability of four monoclonal antibodies (mAb) against different domains of CD31 to modulate the function of T lymphocytes, monocytes and neutrophils. Engagement of CD31 on T lymphocytes results in co-stimulation of T lymphocyte proliferation to suboptimal doses of anti-CD31 mAb. This proliferation is accompanied by secretion of numerous cytokines and chemokines, up-regulation of CD25 and an increase in cell size. Purification of T lymphocytes into CD45RO and CD45RA subsets showed that only naive CD45RA T lymphocytes are co-stimulated by anti-CD31 mAb. Further studies on neutrophils show that engagement of CD31 results in down-regulation of CD62L and up-regulation of CD11b/CD18 as well as oxidative burst, as assessed by superoxide release. In addition, ligation of CD31 on monocytes results in TNF-alpha secretion, and studies with various cell signaling inhibitors indicate that tyrosine kinases and cAMP-dependent kinases are involved in monocyte activation via CD31. Of the four mAb used in this study, only two activated human leukocytes. These mAb were PECAM-1.3 and hec7, which bind to domains 1 and 2 of CD31. We conclude that engagement of domains 1 and 2 of CD31 results in outside-in signaling in leukocytes.     

The effect of desmopressin on platelet aggregation defect in systemic amyloidosis: a preliminary report

The contrasting radiological appearances of metastatic deposits in the mandible of prostatic adenocarcinoma in two patients are described. The clinical presentation was similar in that both presented with altered sensation of the lower lip. Radiologically, they differed in that one patient suffered from a large predominantly osteoblastic mass, while the other, who gave a history of previously treated prostatic adenocarcinoma, presented with a rather small osteolytic deposit. Investigations for bony metastatic disease usually include a bone scan which is a highly sensitive technique although non-specific. A skeletal survey can be useful although less sensitive than a bone scan. Blood investigations such as acid phosphatase and prostate specific antigen levels are also indicated in male patients where prostatic disease is suspected. Reasonable long term survival using relatively simple drug therapy without significant local surgery, highlights the need for accurate recognition and tissue diagnosis to differentiate this condition from osseous malignancy of the jaws, other metastatic disease or osteomyelitis.     

Nerve growth factor induced hyperalgesia in the rat hind paw is dependent on circulating neutrophils

Protected N-(2-hydroxyethyl)-N-(nucleobase-acetyl)aminomethanephosphonic+ ++ acid (6a-d) of all four DNA nucleobases have been prepared and oligomerized by solid-phase synthesis. Four DNA decamers containing 1-10 of these 'PPNA' monomers were prepared and evaluated by Tm measurements (medium salt) for binding to their DNA and RNA complements. One central modification reduced the binding strongly (delta Tm = -10 degrees C), but contiguous PPNA monomers gave smaller effects, and the all-PPNA decamer bound to RNA with a delta Tm of -1.2 degrees C per modification. Thus PPNA oligomers are inferior DNA and RNA binders compared to the closely related and strongly binding PNA oligomers.     

Comparison of susceptibility to apoptosis induced by rhTNF-alpha and cycloheximide between human circulating and exudated neutrophils

OBJECTIVE: Peroxynitrite and hydroxyl radical, reactive oxidants produced during reperfusion, are potent triggers of DNA single strand breakage. DNA injury triggers the activation of the nuclear enzyme poly (ADP-ribose) synthetase (PARS), which contributes to cellular energetic depletion. Using 3-aminobenzamide, an inhibitor of PARS, we investigated the role of PARS in the pathogenesis of myocardial reperfusion injury in a rat model. METHODS AND RESULTS: Occlusion of the left main coronary artery (one hour) followed by reperfusion (one hour) in the anesthetized rat caused severe cardiac necrosis, neutrophil infiltration, and increased plasma creatine phosphokinase activity. There was significant peroxynitrite production during reperfusion, as indicated by a massive increase in nitrotyrosine in the necrotic myocardium. Reperfusion was also associated with a significant loss of myocardial ATP. In vivo administration of the PARS inhibitor 3-aminobenzamide (10 mg/kg i.v.) to rats subjected to myocardial ischemia and reperfusion, reduced myocardial infarct size and blunted the increase in plasma creatine phosphokinase activity and myeloperoxidase activity in infarcted hearts. In addition, 3-aminobenzamide partially preserved the myocardial ATP levels. In vitro, pharmacological inhibition of PARS also ameliorated peroxynitrite-induced cytotoxicity in rat cardiac myocytes and human endothelial cells. CONCLUSION: 3-aminobenzamide has significant protective effects in myocardial reperfusion injury. We hypothesize that activation of PARS activation plays a role in the pathophysiology of acute myocardial infarction.     

Granulocyte colony-stimulating factor administration to healthy volunteers: analysis of the immediate activating effects on circulating neutrophils

In four healthy volunteers, we analyzed in detail the immediate in vivo effects on circulating neutrophils of subcutaneous administration of 300 micrograms of granulocyte colony-stimulating factor (G-CSF). Neutrophil activation was assessed by measurement of degranulation. Mobilization of secretory vesicles was shown by a decrease in leukocyte alkaline phosphatase content of the circulating neutrophils. Furthermore, shortly postinjection, Fc gamma RIII was found to be upregulated from an intracellular pool that we identified by immunoelectron microscopy as secretory vesicles. Intravascular release of specific granules was shown by increased plasma levels of lactoferrin and by upregulation of the expression of CD66b and CD11b on circulating neutrophils. Moreover, measurement of fourfold elevated plasma levels of elastase, bound to its physiologic inhibitor alpha 1-antitrypsin, indicated mobilization of azurophil granules. However, no expression of CD63, a marker of azurophil granules, was observed on circulating neutrophils. G-CSF--induced mobilization of secretory vesicles and specific granules could be mimicked in whole blood cultures in vitro, in contrast to release of azurophil granules. Therefore, we postulate that the most activated neutrophils leave the circulation, as observed shortly postinjection, and undergo subsequent stimulation in the endothelial microenvironment, resulting in mobilization of azurophil granules. Our data demonstrate that G-CSF should be regarded as a potent immediate activator of neutrophils in vivo.     

Zinc aspartate in vivo and in vitro modulation of reactive oxygen species production by human neutrophils and monocytes

In April 1991, an oral health situation analysis team comprising oral health professionals from the Alaska Area Native Health Service, the World Health Organization, and the Moscow Medical Stomatological Institute visited the Magadan region of the Soviet Far East at the request of the Ministries of Health of both the Russian Republic and the then-Soviet Union. As few oral health data had been available specific to the Magadan region, the purpose of the trip was to gather data concerning oral diseases epidemiology, demography, and health systems of the communities of Magadan, Seymchan, and Provideniya as the basis for recommendations and plan development. The data were collected using standard WHO methodology. The analysis team examined children in the age cohorts of 3-5, 6-7, 12, and 15 years. In addition, adults aged 35-44 and 65-74 years were examined in Magadan and Seymchan. Both caries and periodontal rates are high, with a rate of 4.3 DMFT among 12-year-olds in the total region, but up to 5.4 DMFT in one location. Specific findings and recommendations have been forwarded to local community and health officials. The project is ongoing, and plans are underway to provide continuing assistance in designing and implementing an effective program for the prevention and treatment of oral diseases.     

Delayed effect of denervation on wound contraction in rat skin

Neuronal supply in soft tissues may be an important part of cutaneous wound healing. In order to observe the effect of denervation on wound contraction, rectangular full-thickness skin defects were created on the dorsum of two groups of Wistar rats. In the experimental group (n = 20), spinal nerves corresponding to the area of the open wound (T11 to L2) were isolated and divided bilaterally. In the control group (n = 20), the same pairs of spinal nerves were dissected but left intact. Limits of denervation were verified by the pinprick test. Wound healing, which is primarily in the form of wound contraction in this model, was evaluated by tracing wound margins onto millimetric paper weekly. Wound contraction was delayed significantly in the experimental group (p < 0.05) at all follow-up periods when compared with the controls. Loss of neuropeptide secretion from the nerve endings in denervated tissues may be responsible for the retarded wound contraction, since neuropeptides are thought to exert trophic effects on skin wound healing.     

P-selectin glycoprotein ligand 1 is a ligand for L-selectin on neutrophils, monocytes, and CD34+ hematopoietic progenitor cells

Inter-regional trade in live fish as eggs, larvae or juveniles provides the potential for parallel movements of pathogens. Pathogens that exist in a carrier state and/or can be transmitted by vertical means pose the greatest threat since casual observation, and even periods of quarantine or pathogen inspections, may fail to indicate their presence. Additional complications arise with the movements of non-target species for which health examinations may not be required, or for which criteria for pathogen inspections have not been developed. Although international trade in salmonids has been responsible for most of the disease regulations currently in place, an equal or stronger effort should be expected with other species. At the same time, ensuring equal treatment of all trading partners with respect to the level and sophistication of the health examinations to which the product will be subjected is a major problem. There are several examples of past and potential pathogen movements with fish or fish products. Unfortunately, these are often confused by a poor understanding of the current situation in the region into which the animal or product has been imported. The technology, experience or extent of surveillance in the importing region may be insufficient to assess the situation. Distinguishing between exotic imported pathogens and unknown pathogens which are already present in indigenous fish stocks can therefore often be difficult. The author discusses examples of clearly-documented imports of pathogens, as well as the potential for the spread of agents which pose an equal or greater danger. In addition, the author discusses the confusion which often arises when the background into which these pathogens are to move is poorly understood in the importing region.     

Morphological heterogeneity of myeloperoxidase-positive granules in normal circulating neutrophils: an ultrastructural study by cryosection

Ultrastructural localization of myeloperoxidase (MPO) in the granules of human circulating neutrophils was examined by cryosection. On careful comparison with the morphological characteristics of the granules by conventional transmission electron microscopic study, large MPO-positive granules were divided into five types by immunocryoultramicrotomy using monoclonal antibody. Double staining of MPO and lactoferrin (or lysozyme) was also performed. Lactoferrin was generally detected in MPO-negative granules. Lysozyme immunostaining was present in MPO-positive and -negative granules. These data may suggest different functions among large MPO-positive granules of human circulating neutrophils.     

Modulating effect of sodium diethyldithiocarbamate on neutrophils in normal, febrile and cold-stressed rabbits

The studies were conducted on normal, febrile and cold-stressed rabbits. Fever was induced by a single intravenous injection of 1 micrograms/kg of E. coli lipopolysaccharide (LPS). The animals were submerged in ice-water for 20 s and then were kept at -15 degrees C for approx. 8 min., until their body temperature dropped by 3 degrees C. Sodium diethyldithiocarbamate (DTC) was injected i.v. to normal, febrile and cold-stressed rabbits, in a single dose of 2 or 20 mg/kg. The effect of DTC on body temperature, the number of neutrophils in blood, phagocytic activity of neutrophils and their ability to reduce nitroblue tetrazolium (NBT) were evaluated. It was found that DTC administered in a dose of 2 or 20 mg/kg did not affect the body temperature of rabbits. In normal rabbits, DTC did not change the number of neutrophils, but increased their phagocytic activity and ability to reduce NBT. In febrile rabbits, DTC depending on the dose, shortened the stimulating effect of LPS on neutrophil ability to reduce NBT but enhanced and prolonged the effect of pyrogen on neutrophil phagocytic activity. The rabbits treated with DTC prior to hypothermia exhibited shorter neutrophilia resulting from cold stress. In addition, DTC administered to the rabbits before their exposure to cold stress proved to be a partial or even total protection against the decrease in NBT reducing ability and phagocytic activity of blood neutrophils.     

Effect of escalating doses of recombinant human granulocyte colony-stimulating factor (filgrastim) on circulating neutrophils in healthy subjects

The safety profile, tolerability, pharmacodynamics, and pharmacokinetics of four doses of recombinant human granulocyte colony-stimulating factor (filgrastim) were assessed in healthy volunteers in a double-masked, placebo-controlled, parallel-group trial. Healthy subjects received subcutaneous injections of filgrastim 75 microg (n = 8), 150 microg (n = 4), 300 microg (n = 4), 600 microg (n = 8), or placebo (n = 6) daily for 10 consecutive days. Blood samples were drawn daily immediately before the injection and on days 1 and 10 serially throughout the day. Increased absolute neutrophil counts (ANCs) were seen within 90 minutes of drug administration in subjects in all dose groups, peaking approximately 12 hours after administration. This increase was dose related in subjects in the three lower dose groups. The time to peak ANC on day 10 was approximately 9 hours, with a daily ANC profile in all four dose groups that was similar to the profile on day 1. In all dose groups, ANCs were near baseline within 48 hours of discontinuation of filgrastim. Mild, reversible thrombocytopenia was reported in 4 of 10 subjects in the highest dose group. Two subjects in the filgrastim 600-microg group were withdrawn for adverse events. Filgrastim had a good safety profile and caused dose-related increases in ANC when administered to healthy volunteers for up to 10 days.     

Phagocytosis-enhancing effect of lactoferrin on bovine peripheral blood monocytes in vitro and in vivo

The effect of lactoferrin (LF) on in vitro and in vivo phagocytic ability of bovine blood monocytes was studied. It was demonstrated that bovine LF enhanced in vitro phagocytosis of bacteria and ovine erythrocyte-antibody complexes and increased intracellular killing of Staphylococcus albus. Monocytes of colostrum deprived calves, which were intravenously injected with LF, also exhibited elevated phagocytic properties.