Polymorphonucleocytes Research Articles

Trichinella spiralis excretory/secretory products from adult worms inhibit NETosis and regulate the production of cytokines from neutrophils

Upon encountering exogenous pathogens, polymorphonucleocytes (PMNs) engage in various processes to destroy them, including releasing neutrophil extracellular traps (NETs) that trap pathogens and induce phagocytosis and cytokine production. Parasites have unique strategies with which to evade the host's immune response. However, the strategy employed by Trichinella spiralis in response to the reaction of PMNs has yet to be elucidated. This study explored the effect of excretory/secretory products (ESP) on three major functions: NETs, phagocytosis, and cytokine production. Specifically, PMNs were pre-treated with the ESP of 3-day-old adults and then stimulated with phorbol 12-myristate 13-acetate (PMA). We found that in PMNs pretreated with ESP, PMA-induced NET generation was suppressed by ESP. ROS production is a hallmark of PMA-induced NETosis. The LDH assay results showed that ESP inhibits NETs by suppressing ROS rather than promoting PMN death. Furthermore, ESP enhanced Escherichia coli engulfment by PMNs, improving overall phagocytic function. Finally, cytokine analysis revealed an increase in pro-inflammatory cytokine IL-1β, and other cytokines (IL-10, TNF-α), while IL-4 displayed a significant reduction. In conclusion, this study has unraveled T. spiralis' evasion and regulation mechanisms against innate immune cells, providing insights into parasite strategies to manipulate host immunity, potentially informing new treatments for NET-related autoimmune diseases.Graphical

Role of reactive oxygen species and antioxidants in periodontal disease

Recent epidemiological studies reveal that more than two-third of the world’s population suffers from one of the chronic forms of periodontal disease. The primary etiological agent of this inflammatory disease is a polymicrobial complex, predominantly Gram negative anaerobic or facultative bacteria within the sub-gingival biofilm. These bacterial species initiate the production of various cytokines such as interleukin-8 and TNF-α, further causing an increase in number and activity of polymorphonucleocytes (PMN) along with these cytokines, PMNs also produce reactive oxygen species (ROS) superoxide via the respiratory burst mechanism as the part of the defence response to infection. ROS just like the interleukins have deleterious effects on tissue cells when produced in excess. To counter the harmful effects of ROS, human body has its own defence mechanisms to eliminate them as soon as they are formed. The aim of this review is to focus on the role of different free radicals, ROS, and antioxidants in the pathophysiology of periodontal tissue destruction.

ESBL-Producing E. Coli in a Patient on Automated Peritoneal Dialysis

End-stage renal disease (ESRD) is a major cause of morbidity and mortality. Worldwide, an estimated 10-15% of patients with ESRD are on peritoneal dialysis (PD) [1]. Despite its significant role as a successful method of renal replacement therapy, PD is highly associated with peritonitis and catheter-related infections. Patients on PD, regardless of febrile status, who complain of abdominal pain associated with a cloudy dialysate fluid, are highly suspected of peritonitis. A White Blood Cell (WBC) count greater than 100 mm3 comprising more than 50% polymorphonucleocytes (PMNs) confirms the diagnosis and entails immediate treatment [2]. Peritoneal Dialysis (PD) is one of the 3 well-established modalities of renal replacement therapy used in patients with renal failure. Despite its significant role as a successful method of renal replacement therapy, PD is highly associated with peritonitis and catheterrelated infections. ESBL-producing E. coli (ESBL-EC) is uncommonly isolated in the peritoneal dialysate and are resistant to the currently recommended empiric antibiotics for peritoneal dialysis peritonitis (PDP). The optimal treatment of ESBL-EC cultured in the peritoneal dialysate is still lacking. Here, we report a case of 68 years old female on automated peritoneal dialysis, who presented with symptoms of peritonitis, with a peritoneal dialysate culture positive for ESBL-EC.

Emerging Technologies for the Diagnosis of Periprosthetic Infection.

The diagnosis of periprosthetic joint infection remains challenging and relies on a combination of clinical history, physical examination findings, and laboratory tests. The Musculoskeletal Infection Society (MSIS) convened a panel of experts to develop criteria for diagnosing periprosthetic joint infection1. The criteria developed by the workgroup currently represent the most commonly used definition of periprosthetic joint infection. The workgroup identified two major criteria that were indicative of periprosthetic joint infection: (1) the presence of a communicating sinus tract with the prosthesis or (2) the isolation of a pathogen from two different tissue or fluid samples from the joint. In addition, the workgroup identified six minor criteria and indicated that diagnosis of periprosthetic joint infection was very likely when four of the following six criteria were present: (1) an elevated erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) level2, (2) an elevated synovial white blood-cell (WBC) count, (3) an elevated level of synovial polymorphonucleocytes (PMNs), (4) the presence of purulence, (5) the isolation of one pathogen in tissue or fluid, or (6) more than five neutrophils per high-powered field …

Cationic antimicrobial peptides promote microbial mutagenesis and pathoadaptation in chronic infections.

Acquisition of adaptive mutations is essential for microbial persistence during chronic infections. This is particularly evident during chronic Pseudomonas aeruginosa lung infections in cystic fibrosis (CF) patients. Thus far, mutagenesis has been attributed to the generation of reactive species by polymorphonucleocytes (PMN) and antibiotic treatment. However, our current studies of mutagenesis leading to P. aeruginosa mucoid conversion have revealed a potential new mutagen. Our findings confirmed the current view that reactive oxygen species can promote mucoidy in vitro, but revealed PMNs are proficient at inducing mucoid conversion in the absence of an oxidative burst. This led to the discovery that cationic antimicrobial peptides can be mutagenic and promote mucoidy. Of specific interest was the human cathelicidin LL-37, canonically known to disrupt bacterial membranes leading to cell death. An alternative role was revealed at sub-inhibitory concentrations, where LL-37 was found to induce mutations within the mucA gene encoding a negative regulator of mucoidy and to promote rifampin resistance in both P. aeruginosa and Escherichia coli. The mechanism of mutagenesis was found to be dependent upon sub-inhibitory concentrations of LL-37 entering the bacterial cytosol and binding to DNA. LL-37/DNA interactions then promote translesion DNA synthesis by the polymerase DinB, whose error-prone replication potentiates the mutations. A model of LL-37 bound to DNA was generated, which reveals amino termini α-helices of dimerized LL-37 bind the major groove of DNA, with numerous DNA contacts made by LL-37 basic residues. This demonstrates a mutagenic role for antimicrobials previously thought to be insusceptible to resistance by mutation, highlighting a need to further investigate their role in evolution and pathoadaptation in chronic infections.

Reactive oxygen species in periodontitis

Recent epidemiological studies reveal that more than two-third of the world's population suffers from one of the chronic forms of periodontal disease. The primary etiological agent of this inflammatory disease is a polymicrobial complex, predominantly Gram negative anaerobic or facultative bacteria within the sub-gingival biofilm. These bacterial species initiate the production of various cytokines such as interleukin-8 and TNF-α, further causing an increase in number and activity of polymorphonucleocytes (PMN) along with these cytokines, PMNs also produce reactive oxygen species (ROS) superoxide via the respiratory burst mechanism as the part of the defence response to infection. ROS just like the interleukins have deleterious effects on tissue cells when produced in excess. To counter the harmful effects of ROS, human body has its own defence mechanisms to eliminate them as soon as they are formed. The aim of this review is to focus on the role of different free radicals, ROS, and antioxidants in the pathophysiology of periodontal tissue destruction.

Administration of nitrite after chlorine gas exposure prevents lung injury: Effect of administration modality

Cl2 gas toxicity is complex and occurs during and after exposure, leading to acute lung injury (ALI) and reactive airway syndrome (RAS). Moreover, Cl2 exposure can occur in diverse situations encompassing mass casualty scenarios, highlighting the need for postexposure therapies that are efficacious and amenable to rapid and easy administration. In this study, we assessed the efficacy of a single dose of nitrite (1mg/kg) to decrease ALI when administered to rats via intraperitoneal (ip) or intramuscular (im) injection 30min after Cl2 exposure. Exposure of rats to Cl2 gas (400ppm, 30min) significantly increased ALI and caused RAS 6–24h postexposure as indexed by BAL sampling of lung surface protein and polymorphonucleocytes (PMNs) and increased airway resistance and elastance before and after methacholine challenge. Intraperitoneal nitrite decreased Cl2-dependent increases in BAL protein but not PMNs. In contrast im nitrite decreased BAL PMN levels without decreasing BAL protein in a xanthine oxidoreductase-dependent manner. Histological evaluation of airways 6h postexposure showed significant bronchial epithelium exfoliation and inflammatory injury in Cl2-exposed rats. Both ip and im nitrite improved airway histology compared to Cl2 gas alone, but more coverage of the airway by cuboidal or columnar epithelium was observed with im compared to ip nitrite. Airways were rendered more sensitive to methacholine-induced resistance and elastance after Cl2 gas exposure. Interestingly, im nitrite, but not ip nitrite, significantly decreased airway sensitivity to methacholine challenge. Further evaluation and comparison of im and ip therapy showed a twofold increase in circulating nitrite levels with the former, which was associated with reversal of post-Cl2 exposure-dependent increases in circulating leukocytes. Halving the im nitrite dose resulted in no effect in PMN accumulation but significant reduction of BAL protein levels, indicating a distinct nitrite dose dependence for inhibition of Cl2-dependent lung permeability and inflammation. These data highlight the potential for nitrite as a postexposure therapeutic for Cl2 gas-induced lung injury and also suggest that administration modality is a key consideration in nitrite therapeutics.

Polyphenolic fraction of Lonicera caerulea L. fruits reduces oxidative stress and inflammatory markers induced by lipopolysaccharide in gingival fibroblasts

The most common oral diseases have a microbial aetiology. Pathogenic bacteria liberate a number of irritating agents including a lipopolysaccharide (LPS) that activates pro-inflammatory cytokines promoting increased activity of polymorphonucleocytes (PMN). Release of PMN-derived free radicals into an infected gingival area affects gums, periodontal ligaments and alveolar bone. Berries of Lonicera caerulea L. (blue honeysuckle) are rich in phenolics, particularly phenolic acids, flavonoids and anthocyanins that have multiple biological activities in vitro and in vivo such as antiadherence, antioxidant and anti-inflammatory. Studies have shown that polyphenols suppress a number of LPS-induced signals and thus could be effective against gingivitis. Here we assessed effects of the polyphenolic fraction of L. caerulea fruits (PFLC; containing 77% anthocyanins) on LPS-induced oxidative damage and inflammation in human gingival fibroblasts. Application of PFLC (10–50μg/ml) reduced reactive oxygen species (ROS) production, intracellular glutathione (GSH) depletion as well as lipid peroxidation in LPS-treated cells. PFLC treatment also inhibited LPS-induced up-regulation of interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) and it suppressed expression of cyclooxygenase-2 (COX-2). The effects are presumably linked to its antioxidant and anti-inflammatory activities and suggest its use in attenuating the inflammatory process, including periodontal disease.

Recent Advances in Improving Sub-Unit Vaccine Efficacy Using Cytokines as more Specific Immune Inducing Adjuvants

Current vaccine research is now heavily focused on improving the efficacy and potency of sub-unit peptide vaccines. Many successful vaccines developed in past decades have been able to sufficiently prime proper immune responses without the use of any specific adjuvant immune mediators. Due to the intrinsic nature of more immune-evading pathogens and neoplasms, novel “tricks” are needed to elucidate a proper and protective immune response. It is important to note that without cytokines, proper execution of the immune response would be completely inhibited. They are responsible for the recruitment and chemo-tactic movement of most innate cellular effectors such as polymorphonucleocytes (PMN), macrophages, and dendritic cells. Most importantly, the entire Th1/Th2 balance is completely dependent on the unique nature and signature of differential cytokine production. These expression signatures are crucially needed to tip the scale either way, depending on which immune reaction is appropriate. This review will specifically explain the use of Th1 inducing cytokines as an adjuvant in current vaccine development. This rapidly developing field aims to produce more powerful and effective Th1 responses in the hopes of improving the treatment of cancer, intracellular infectious agents, and autoimmune diseases.

Intramammary infusion of a live culture for treatment of bovine mastitis: effect of live lactococci on the mammary immune response

In the accompanying article, we demonstrated that a live culture of Lactococcus lactis compares favourably with antibiotics for treatment of bovine mastitis in two initial field trials. In an effort to explain the mechanism involved, this study investigated the effect of culture administration on the local immune response. In this respect we initially observed that infusion of the live culture Lactococcus lactis stimulated substantial recruitment of polymorphonucleocytes (PMN) and lymphocytes to the udder. For instance, in one assay, quarters infused with the probiotic experienced a dramatic increase (approximately 20,000-fold) in neutrophils over the first 48-h period from an average value of 83.6 cells/ml pre-treatment to 1.78 x 106 cells/ml 48 h post-infusion. Levels of the acute phase proteins haptaglobin and milk amyloid A were also elevated significantly in comparison with controls following infusion of the culture. The results of flow cytometric assays also demonstrated that while infusion of a live lactococcal culture led to an enhanced recruitment of PMN to the udder (from 1.85 x 104 cells/ml pre-infusion to 1.45 x 106 cells/ml 24 h post-infusion) cell-free supernatant from the same culture was not able to do so, indicating that live Lc. lactis can specifically trigger the mammary immune response to elicit PMN accumulation. These results suggest that the mechanism responsible for this probiotic treatment of mastitis is associated with stimulation of the host intramammary immune system.

Effect of administration of fish oil on aspects of cell-mediated immune response in periparturient dairy goats

Ten days before kidding, 18 Saanen dairy goats were divided into matched control (C) and fish oil-administered (FO) groups of nine animals each. The FO group received 27 g per day cod liver oil from 10 days before kidding to parturition, and 45 g per day cod liver oil from kidding to 15th day of lactation. Skin tests were performed 4 days before, and 4 and 15 days after parturition at 0, 8, 16, and 24 h after injection of 250 μg of phytohaemagglutinin (PHA). Blood plasma was sampled 10 and 4 days before, and 4 and 15 days after parturition for differential leukocyte count. Serum lysozyme content was determined by lyso plate assay with Micrococcus lysodeikticus. FO supplementation significantly increased skin thickness after PHA injection, and blood lymphocyte levels on day 4 of lactation, while polymorphonucleocytes (PMNs) were significantly increased 4 days before and 4 days after kidding. There were no differences in the proportion of monocytes. Serum lysozyme levels were significantly lower in the FO group. We conclude that administration of cod liver oil may improve some aspects of the cell-mediated immune response around the periparturient period in the goat.

Salivary antioxidants and periodontal disease status.

Periodontal disease is a common chronic adult condition. The bacterium Porphyromonas gingivalis has been implicated in the aetiology of this disease, which causes destruction of the connective tissue and bone around the root area of the tooth. It has been observed that invading P. gingivalis bacteria trigger the release of cytokines such as interleukin 8 and tumour necrosis factor a, leading to elevated numbers and activity of polymorphonucleocytes (PMN). As a result of stimulation by bacterial antigens, PMN produce the reactive oxygen species (ROS) superoxide via the respiratory burst as part of the host response to infection. Patients with periodontal disease display increased PMN number and activity. It has been suggested that this proliferation results in a high degree of ROS release, culminating in heightened oxidative damage to gingival tissue, periodontal ligament and alveolar bone. Antioxidant constituents in plasma have been well-documented, being chiefly ascorbate, albumin and urate, and these are known to display sensitivity to dietary antioxidant intakes. The concentration of antioxidants in saliva does not appear to mirror those of plasma. The extent of dietary influence upon salivary antioxidant status is unclear. Urate is the predominant salivary antioxidant, with albumin and ascorbate providing minor contributions. Previous research has found reduced salivary antioxidant activity in patients suffering from periodontal disease. An improved understanding of the role antioxidants play in periodontitis, and the influence of nutrition on antioxidant status, may lead to a possible nutritional strategy for the treatment of periodontal disease.

The Relevance of Blood Cell-Vessel Wall Adhesive Interactions for Vascular Thrombotic Disease

Activation and signaling of circulating blood and vessel wall cells, as well as their direct adhesive interactions, are critical for the regulation of vascular homeostasis related to vasomotor responses, inflammation, hemostasis, and wound repair. Under conditions of stress, inflammation, or infection the targeting and anchoring of leukocytic cells to the vascular endothelium is mediated by specific pairs of adhesion receptors and their counter-ligands that may induce juxtacrine signaling resulting in the expression of prothrombotic agonists such as tissue factor. Concomitant action of inflammatory cytokines may down-regulate thromboprotective mechanisms of the endothelium. Through similar intercellular interactions, the platelets recruited to these inflamed sites may aggregate and modulate leukocyte function. In addition, leukocytes can influence coagulation by their ability to produce pro- and anticoagulant factors as well as by providing specific receptors (such as Mac-1 or EPR-1) that serve as direct molecular links between inflammation and hemostasis. The initiation and amplification of blood clotting reactions on the leukocyte surface has consequences on other vascular cell functions and involves (cytokine) activation and signaling pathways that contribute to pathophysiological aspects of inflammatory responses. As a consequence, the diverse cell-to-cell interactions, as well as different inflammatory mediators or bidirectional signaling pathways, appear to be promising targets for the treatment of thrombotic complications in the context of inflammation-dependent vascular diseases.

Regulatory Mechanisms of Arachidonic Acid Metabolism in Polymorphonucleocytes (PMNs)

Regulatory Mechanisms of Arachidonic Acid Metabolism in Polymorphonucleocytes (PMNs)

Delivery of liposome-sequestered hydrophobic proteins to lysosomes of normal and Batten disease cells.

We have developed a method to deliver hydrophobic proteins such as ATP synthase subunit c and ubiquitin to lysosomes of PMN (polymorphonucleocytes) and fibroblasts. ATP synthase subunit c is stored in the lysosomes of various tissues in late infantile and juvenile forms of neuronal ceriod lipofuscinosis, also called Batten disease (BD). Whether this protein storage is due to an abbreviation in protein or in the lysosomal hydrolases of BD is still not clear. We have sequestered this protein and ubiquitin in the lipid membrane of liposomes. The liposomes coated with autologous heat-aggregated IgG or apolipoprotein E when presented to the PMN and fibroblasts, respectively, accumulated in the lysosomes. Both normal and BD PMN degraded 125I-ubiquitin; the rate of degradation was, however, slower by Batten PMN. These studies indicate that a hydrophobic molecule such as subunit c can be delivered to PMN and fibroblasts, and the sequestered proteins are accessible to lysosomal hydrolases. Therefore, this technique can be used to study the metabolism of highly hydrophobic proteins by lysosomes, especially the biochemical mechanism(s) of subunit c storage in BD.

7] Measurement of nitric oxide and hydrogen peroxide production from human neutrophils

Publisher Summary This chapter discusses the measurement of nitric oxide (NO) and hydrogen peroxide production from human neutrophils. Human neutrophils, polymorphonucleocytes (PMNs) exposed to soluble or particulate stimuli largely increase cyanide-insensitive oxygen consumption with the production of reactive oxygen species in a process termed the respiratory burst, which seems responsible for the microbicidal activity of PMNs. Circulating human neutrophils release NO when they are exposed to appropriate stimuli by activation of a constitutive nitric oxide synthase (NOS), while inflammatory neutrophils appear to express an inducible NOS. The NO and superoxide anion (O 2 – ) are able to interact to form peroxynitrite 1° and other reactive species that apparently contribute to host defense against infections. NO production is measured in a double beam-double wavelength 356 Perkin–Elmer spectrophotometer. A direct measurement of released NO can be made with Clark-type nitric oxide selective electrodes. Neutrophils release NO after stimulation either with phorbol esters such as phorbol myristate acetate (PMA) or with formylmethionylleucylphenylalanine (fMLP); typical traces showing the spectrophotometric changes in performing the oxymyoglobin assay. The detection of nitrite (and nitrate) is useful for high cell concentrations such as those in culture.

ATP synthase subunit c storage in the polymorphonucleocytes of late infantile and juvenile batten patients

In late infantile and juvenile forms of neuronal ceroid lipofuscinosis, commonly known as Batten disease (BD), ATP synthase subunit c accumulates in the lysosomes of neural cells. By using polyclonal antibodies, raised against bovine liver subunit c and an image analysis system for the quantification of antibody-linked alkaline phosphatase reaction, we have demonstrated that polymorphonucleocytes (PMN) from a late infantile and a juvenile BD patient stored several-fold more subunit c as compared to normal PMN.

Evaluation of Urine-Based Screening Strategies to Detect Chlamydia trachomatis Among Sexually Active Asymptomatic Young Males

To evaluate the performances of diagnostic screening tests alone or in combination to detect asymptomatic chlamydial urethral infection in young males. Comparisons of the performance profiles of the following chlamydia screening strategies were done: urethral culture; identification of polymorphonucleocytes (PMNs) on spun first-void urine (FVU); urinary leukocyte esterase test (LET) on unspun FVU; chlamydial enzyme immunoassay (EIA) applied to FVU sediment; combining LET on unspun FVU followed by EIA with or without direct fluorescent antibody (DFA) confirmation on FVU sediment; and combining PMNs on spun FVU followed by EIA with or without DFA confirmation. General clinics at a youth detention center, university-based teen clinic, college health service, and a military screening clinic. A total of 618 males aged 12 to 35 years (mean, 17 years) were recruited as a convenience sample; site participation rates ranged from 50% to 80%. Eligible subjects were sexually active, denied symptoms of urethritis, and had taken no antibiotics in the prior 2 weeks. Sensitivity, specificity, and positive and negative predictive values of each test strategy's ability to detect Chlamydia trachomatis infection, and cost to confirm each positive case. With a 7% prevalence of chlamydial infection, tissue culture had a sensitivity of only 61%. However, two strategies yielded significantly better performance profiles compared with the others: EIA confirmed by DFA test with a sensitivity of 84%, a specificity of 100%, and a cost to identify each positive case of $434; and PMNs followed by EIA confirmed by DFA test with a sensitivity of 78%, a specificity of 100%, and a cost to identify each positive case of $199. The LET followed by EIA-DFA had a similar performance profile to the PMN test strategies. A combination of a nonspecific screening of FVU for PMNs or LET followed by specific testing with EIA with DFA confirmation has superior clinical and cost-effective performance for detecting asymptomatic C trachomatis urethritis in young males compared with other strategies. However, an evaluation of the medical, fiscal, and psychological benefits and risks associated with a specific screening strategy for sexually transmitted diseases must be made before adopting a specific strategy for a particular population.

The integrity of experimental vein graft endothelium—implications on the etiology of early graft failure

the vascular endothelium serves as a functional barrier between the circulating blood and the vessel wall. It is an essential element for the maintenance of vascular homeostasis and is implicated in the pathogenesis of vascular disease. Reversed vein bypass grafting is considered to be a devastating procedure for the endothelial cell layer of the graft during the first 7 days. At this time, smooth muscle cell proliferation, the forerunner of intimal hyperplasia, begins. Loss of endothelial cell integrity is cited as an important factor in this smooth muscle cell response. The integrity of the vein graft endothelial lining after grafting was examined in this study. reversed vein bypass grafting of the common carotid artery using external jugular vein was performed in 24 New Zealand white rabbits. All grafts were pressure fixed (80 mmHg) in situ, at 0 and 10 min, 6 h and 1, 3, 5, 7 and 14 days postoperatively. The endothelial cell layer was examined by light microscopy (LM), scanning (SEM) and transmission electron microscopy (TEM) and immunohistochemistry (Factor VIII) using standard histological procedures. the endothelium was observed by SEM and confirmed by both LM, Factor VIII and TEM in all specimens. It covered almost the entire surface examined. At 0 and 10 min, endothelial cells were present and displayed minimal evidence of injury. At 6 h and 1 day, numerous red cells, polymorphonucleocytes (PMNs), platelets and fibrin were adherent to the luminal surface. Blood cells were also seen beneath the endothelium. At day 3, the adherent fibrin and cellular elements were reduced with most of the endothelial lining intact. Within 10 min, TEM demonstrated that these cells were stretched, very thin with few microvesicles and a blurred cytoplasm, which would indicate viability but a degree of cellular injury. By day 1, the endothelial cells were lifted from their underlying structures by subendothelial oedema and an infiltrate predominantly of PMNs. By day 5, the blood cells and fibrin which were adherent to the endothelium had been dispersed and the subendothelial infiltrate was to a large extent replaced by disintegrated PMNs. On days 7 and 14, a viable confluent endothelial cell layer was present and a degree of intimal hyperplasia was noted. The endothelial cells appeared to have enlarged nucleoli and cytoplasms filled with a considerable quantity of rough endoplasmic reticulum. the endothelium of reversed vein grafts is preserved at the time of implantation and at all time intervals studied in this model. These findings do not support the assumption that endothelial denudation is a prerequisite for intimal hyperplasia. Endothelial cell dysfunction and morphological changes are maximal within the first 3 days after grafting but appear to recover by the 5th postoperative day. The gross preservation of the endothelial cell layer implies that therapeutic approaches, to mitigate endothelial cell injury and its consequences, should be focused on the preoperative period and the first 5 days following implantation.

Modulation of Neonatal Rat Myeloid Kinetics Resulting in Peripheral Neutrophilia by Single Pulse Administration of Rh Granulocyte-Macrophage Colony-Stimulating Factor and Rh Granulocyte Colony-Stimulating Factor

Rh granulocyte-macrophage (GM) colony-stimulating factor (CSF) and rh granulocyte (G) CSF have been demonstrated to induce proliferation and maturation of myeloid stem cells and release of mature polymorphonucleocytes (PMNs) from human and animal adult bone marrows. Unfortunately, reduced bone marrow progenitor cells, neutrophil storage pool (NSP) depletion and peripheral neutropenia are characteristic of human and animal newborn bone marrows. We investigated the effect of administering intraperitoneal rhGM-CSF and rhG-CSF to Sprague-Dawley newborn rats (less than 36 h). Newborn rats treated with intraperitoneal CSF (3.0 micrograms/kg) demonstrated significant leukocytosis at 6 and 24 h: rhGM-CSF vs. control, WBC (10(3)/mm3), at 6 h, 8.0 +/- 0.5 vs 4.3 +/- 0.9 (p less than or equal to 0.003), and at 24 h, 7.7 +/- 1.7 vs. 3.8 +/- 0.2 (p less than or equal to 0.008); rhG-CSF vs. control WBC (10(3)/mm3) at 6 h, 6.6 +/- 1.2 vs 4.3 +/- 0.1 (p less than or equal to 0.03), and at 24 h, 8.1 +/- 0.2 vs. 3.75 +/- 0.2 (p less than or equal to 0.003). The absolute neutrophil count was also significantly elevated at 6 h following intraperitoneal CSF (3.0 micrograms/kg): RhGM-CSF vs. control 1,827 +/- 25 vs. 379 +/- 10 (p less than or equal to 0.001); rhG-CSF vs. control, 1,698 +/- 40 vs. 371 +/- 10.1 (p less than or equal to 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)