ABSTRACT
INTRODUCTION: Intranasal deferoxamine (IN DFO) has been shown to decrease memory loss and have beneficial impacts across several models of neurologic disease and injury, including rodent models of Alzheimer's and Parkinson's disease. METHODS: In order to assess the mechanism of DFO, determine its ability to improve memory from baseline in the absence of a diseased state, and assess targeting ability of intranasal delivery, we treated healthy mice with IN DFO (2.4 mg) or intraperitoneal (IP) DFO and compared behavioral and biochemical changes with saline-treated controls. Mice were treated 5 days/week for 4 weeks and subjected to behavioral tests 30 min after dosing. RESULTS: We found that IN DFO, but not IP DFO, significantly enhanced working memory in the radial arm water maze, suggesting that IN administration is more efficacious as a targeted delivery route to the brain. Moreover, the ability of DFO to improve memory from baseline in healthy mice suggests a non-disease-specific mechanism of memory improvement. IN DFO treatment was accompanied by decreased GSK-3ß activity and increased HIF-1α activity. CONCLUSIONS: These pathways are suspected in DFO's ability to improve memory and perhaps represent a component of the common mechanism through which DFO enacts beneficial change in models of neurologic disease and injury.
Subject(s)
Brain/drug effects , Deferoxamine/administration & dosage , Memory, Short-Term/drug effects , Siderophores/administration & dosage , Administration, Intranasal , Animals , Brain/metabolism , Glycogen Synthase Kinase 3 beta/metabolism , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Male , MiceABSTRACT
Deferoxamine, a metal chelator, has been shown to be neuroprotective in animal models of ischemic stroke, traumatic brain injury and both subarachnoid and intracerebral hemorrhage. Intranasal deferoxamine (IN DFO) has also shown promise as a potential treatment for multiple neurodegenerative diseases, including Parkinson's and Alzheimer's. However, there have been no attempts to thoroughly understand the dynamics and pharmacokinetics of IN DFO. We developed a new high-performance liquid-chromatography electrospray-tandem mass spectrometry (HPLC/ESI-MS2) method to quantify the combined total levels of DFO, ferrioxamine (FO; DFO bound to iron), and aluminoxamine (AO; aluminum-bound DFO) in brain tissue using a custom-synthesized deuterated analogue (DFO-d7, Medical Isotopes Inc., Pelham NH) as an internal standard. We applied our method toward understanding the pharmacokinetics of IN DFO delivery to the brain and blood of rats from 15 min to 4 h after delivery. We found that IN delivery successfully targets DFO to the brain to achieve concentrations of 0.5-15 µM in various brain regions within 15 min, and decreasing though still detectable after 4 h. Systemic exposure was minimized as assessed by concentration in blood serum. Serum concentrations were 0.02 µM at 15 min and no more than 0.1 µM at later time points. Compared to blood serum, brain region-specific drug exposure (as measured by area under the curve) ranged from slightly under 10 times exposure in the hippocampus to almost 200 times exposure in the olfactory bulb with IN DFO delivery. These findings represent a major step toward future method development, pharmacokinetic studies, and clinical trials for this promising therapeutic.
Subject(s)
Brain/drug effects , Brain/metabolism , Deferoxamine/administration & dosage , Deferoxamine/metabolism , Siderophores/administration & dosage , Siderophores/metabolism , Administration, Intranasal , Animals , Brain Chemistry/drug effects , Brain Chemistry/physiology , Deferoxamine/analysis , Mass Spectrometry/methods , Rats , Rats, Sprague-Dawley , Siderophores/analysisABSTRACT
This theoretical paper presents a public health approach for promoting self-regulation across development that is based in cross-disciplinary theory and research. The self-regulation promotion model includes three key approaches that are each dependent on the relationship that children and youth have with caregivers: teaching self-regulation skills, building supportive environments, and providing co-regulation. This model extends the science of self-regulation insofar as it: (1) focuses on promoting wellbeing (not only reducing risks) across domains of functioning, (2) addresses self-regulation intervention across childhood and through young adulthood, (3) integrates multiple theories and applies them to intervention in meaningful ways, and (4) identifies specific strategies that can be used in natural developmental contexts and that address the social ecological environment as well as the individual child. We describe seven key principles that support the model including a description of self-regulation processes and implications for promoting self-regulation at each developmental stage. We end with broad implications for intervention, highlighting the relevance of the self-regulation promotion model for practitioners, policy makers, and prevention researchers.
Subject(s)
Biomedical Research/methods , Human Development , Preventive Medicine/methods , Public Health/methods , Self-Control , Adolescent , Child , Health Promotion , Humans , Models, Theoretical , Self-Control/psychology , Young AdultABSTRACT
Intranasal administration is an attractive route for systemic delivery of small, lipophilic drugs because they are rapidly absorbed through the nasal mucosa into systemic circulation. However, the low solubility of lipophilic drugs often precludes aqueous nasal spray formulations. A unique approach to circumvent solubility issues involves coadministration of a hydrophilic prodrug with an exogenous converting enzyme. This strategy not only addresses poor solubility but also leads to an increase in the chemical activity gradient driving drug absorption. Herein, we report plasma and brain concentrations in rats following coadministration of a hydrophilic diazepam prodrug, avizafone, with the converting enzyme human aminopeptidase B Single doses of avizafone equivalent to diazepam at 0.500, 1.00, and 1.50 mg/kg were administered intranasally, resulting in 77.8% ± 6.0%, 112% ± 10%, and 114% ± 7% bioavailability; maximum plasma concentrations 71.5 ± 9.3, 388 ± 31, and 355 ± 187 ng/ml; and times to peak plasma concentration 5, 8, and 5 minutes for each dose level, respectively. Both diazepam and a transient intermediate were absorbed. Enzyme kinetics incorporated into a physiologically based pharmacokinetic model enabled estimation of the first-order absorption rate constants: 0.0689 ± 0.0080 minutes-1 for diazepam and 0.122 ± 0.022 minutes-1 for the intermediate. Our results demonstrate that diazepam, which is practically insoluble, can be delivered intranasally with rapid and complete absorption by coadministering avizafone with aminopeptidase B. Furthermore, even faster rates of absorption might be attained simply by increasing the enzyme concentration, potentially supplanting intravenous diazepam or lorazepam or intramuscular midazolam in the treatment of seizure emergencies.
Subject(s)
Anticonvulsants/administration & dosage , Diazepam/administration & dosage , Dipeptides/administration & dosage , Prodrugs/administration & dosage , Administration, Intranasal , Aminopeptidases/chemistry , Aminopeptidases/metabolism , Animals , Anticonvulsants/adverse effects , Anticonvulsants/pharmacokinetics , Biological Availability , Diazepam/pharmacokinetics , Dipeptides/adverse effects , Dipeptides/pharmacokinetics , Drug Compounding , Male , Nasal Cavity/cytology , Nasal Cavity/metabolism , Prodrugs/pharmacokinetics , Rats , Rats, Sprague-DawleyABSTRACT
The ability of a novel intranasally delivered amnion cell derived biologic to suppress inflammation, prevent neuronal damage and preserve neurologic function in the experimental autoimmune encephalomyelitis animal model of multiple sclerosis was assessed. Currently, there are no existing optic nerve treatment methods for disease or trauma that result in permanent vision loss. Demyelinating optic nerve inflammation, termed optic neuritis, induces permanent visual dysfunction due to retinal ganglion cell damage in multiple sclerosis and experimental autoimmune encephalomyelitis. ST266, the biological secretome of Amnion-derived Multipotent Progenitor cells, contains multiple anti-inflammatory cytokines and growth factors. Intranasally administered ST266 accumulated in rodent eyes and optic nerves, attenuated visual dysfunction, and prevented retinal ganglion cell loss in experimental optic neuritis, with reduced inflammation and demyelination. Additionally, ST266 reduced retinal ganglion cell death in vitro. Neuroprotective effects involved oxidative stress reduction, SIRT1-mediated mitochondrial function promotion, and pAKT signaling. Intranasal delivery of neuroprotective ST266 is a potential novel, noninvasive therapeutic modality for the eyes, optic nerves and brain. The unique combination of biologic molecules in ST266 provides an innovative approach with broad implications for suppressing inflammation in autoimmune diseases, and for preventing neuronal damage in acute neuronal injury and chronic neurodegenerative diseases such as multiple sclerosis.
Subject(s)
Amnion/metabolism , Biological Factors/administration & dosage , Encephalomyelitis, Autoimmune, Experimental/metabolism , Encephalomyelitis, Autoimmune, Experimental/pathology , Neurons/drug effects , Neurons/metabolism , Administration, Intranasal , Animals , Axons/metabolism , Cell Survival/drug effects , Demyelinating Diseases , Disease Models, Animal , Encephalomyelitis, Autoimmune, Experimental/drug therapy , Female , Mice , Neurons/pathology , Neuroprotective Agents/pharmacology , Optic Nerve/metabolism , Optic Nerve/pathology , Optic Neuritis/etiology , Optic Neuritis/metabolism , Optic Neuritis/pathology , Rats , Retinal Ganglion Cells/drug effects , Retinal Ganglion Cells/metabolism , Signal Transduction/drug effectsABSTRACT
Hypocretin-1 (HC, orexin-A) is a neuropeptide involved in regulating physiological functions of sleep, appetite and arousal, and it has been shown that intranasal (IN) administration can target HC to the brain. Recent clinical studies have shown that IN HC has functional effects in human clinical trials. In this study, we use rats to determine whether IN HC has an immediate effect on food consumption and locomotor activity, whether distribution in the brain after IN delivery is dose-dependent, and whether MAPK and PDK1 are affected after IN delivery. Food intake and wheel-running activity were quantified for 24h after IN delivery. Biodistribution was determined 30min after IN delivery of both a high and low dose of 125I-radiolabelled HC throughout the brain and other bodily tissues, while Western blots were used to quantify changes in cell signaling pathways (MAPK and PDK1) in the brain. Intranasal HC significantly increased food intake and wheel activity within 4h after delivery, but balanced out over the course of 24h. The distribution studies showed dose-dependent delivery in the CNS and peripheral tissues, while PDK1 was significantly increased in the brain 30min after IN delivery of HC. This study adds to the growing body of evidence that IN administration of HC is a promising strategy for treatment of HC related behaviors.
Subject(s)
Eating/drug effects , Motor Activity/drug effects , Orexins/administration & dosage , Administration, Intranasal , Animals , Brain Chemistry , Drinking/drug effects , Male , Mitogen-Activated Protein Kinase 1/metabolism , Orexins/analysis , Protein Serine-Threonine Kinases/metabolism , Pyruvate Dehydrogenase Acetyl-Transferring Kinase , Rats , Rats, Sprague-Dawley , Signal Transduction , Spinal Cord/chemistryABSTRACT
The revised Society for Prevention Research (SPR) standards of evidence are an exciting advance in the field of prevention science. We appreciate the committee's vision that the standards represent goals to aspire to rather than a set of benchmarks for where prevention science is currently. The discussion about the standards highlights how much has changed in the field over the last 10 years and as knowledge, theory, and methods continue to advance, the new standards push the field toward increasing rigor and relevance. This commentary discusses how the revised standards support work of translating high-quality evaluations to support evidence-based policy and work supporting evidence-based programs' ability to implement at scale. The commentary ends by raising two areas, generating evidence at scale and transparency of research, as additional areas for consideration in future standards.
Subject(s)
Evidence-Based Medicine , Preventive Health Services/organization & administration , ResearchABSTRACT
Intranasal administration is a method of delivering therapeutic agents to the central nervous system (CNS). It is non-invasive and allows large molecules that do not cross the blood-brain barrier access to the CNS. Drugs are directly targeted to the CNS with intranasal delivery, reducing systemic exposure and thus unwanted systemic side effects. Delivery from the nose to the CNS occurs within minutes along both the olfactory and trigeminal neural pathways via an extracellular route and does not require drug to bind to any receptor or axonal transport. Intranasal delivery is a widely publicized method and is currently being used in human clinical trials. Intranasal delivery of drugs in animal models allows for initial evaluation of pharmacokinetic distribution and efficacy. With mice, it is possible to administer drugs to awake (non-anesthetized) animals on a regular basis using a specialized intranasal grip. Awake delivery is beneficial because it allows for long-term chronic dosing without anesthesia, it takes less time than with anesthesia, and can be learned and done by many people so that teams of technicians can dose large numbers of mice in short periods. Efficacy of therapeutics administered intranasally in this way to mice has been demonstrated in a number of studies including insulin in diabetic mouse models and deferoxamine in Alzheimer's mouse models. The intranasal grip for mice can be learned, but is not easy and requires practice, skill, and a precise grip to effectively deliver drug to the brain and avoid drainage to the lung and stomach. Mice are restrained by hand using a modified scruff in the non-dominant hand with the neck held parallel to the floor, while drug is delivered with a pipettor using the dominant hand. It usually takes 3-4 weeks of acclimating to handling before mice can be held with this grip without a stress response. We have prepared this JoVE video to make this intranasal delivery technique more accessible.
Subject(s)
Administration, Intranasal/methods , Administration, Intranasal/veterinary , Central Nervous System/metabolism , Animals , Consciousness , Mice , Olfactory Nerve/metabolism , Trigeminal Nerve/metabolismABSTRACT
OBJECTIVES: Intranasal delivery has been shown to target peptide therapeutics to the central nervous system (CNS) of animal models and induce specific neurological responses. In an investigation into the pathways by which intranasal administration delivers insulin to the CNS, this study has focused on the direct delivery of insulin from the olfactory mucosa to the olfactory bulbs via the olfactory nerve pathway. METHODS: Nasal and olfactory tissues of mice were imaged with fluorescent and electron microscopy 30 min following intranasal administration. KEY FINDINGS: Macroscopic analysis confirmed delivery to the anterior regions of the olfactory bulbs. Confocal microscopy captured delivery along the olfactory nerve bundles exiting the nasal mucosa, traversing the cribriform plate and entering the bulbs. With electron microscopy, insulin was found within cells of the olfactory nerve layer and glomerular layer of the olfactory bulbs. CONCLUSIONS: These results demonstrated that intranasal administration of labelled insulin targeted the CNS through the olfactory nerve pathway in mice.
Subject(s)
Administration, Intranasal , Insulin/administration & dosage , Nasal Mucosa/metabolism , Olfactory Nerve/metabolism , Olfactory Pathways/metabolism , Animals , Central Nervous System/metabolism , Ethmoid Bone/metabolism , Insulin/metabolism , Male , Mice , Mice, Inbred C57BL , Microscopy/methods , Olfactory Bulb/metabolismABSTRACT
Intranasal administration, which bypasses the blood-brain barrier and minimizes systemic exposure, is a non-invasive alternative for targeted drug delivery to the brain. While identification of metal dysregulation in Alzheimer's brain has led to the development of therapeutic metal-binding agents, targeting to the brain has remained an issue. The purpose of this study was to both determine concentrations of deferoxamine (DFO), a high-affinity iron chelator, reaching the brains of mice after intranasal administration and to determine its efficacy in a mouse model of spatial memory loss. Intranasal administration of DFO (2.4 mg) labeled with (59)Fe (75 µCi) to C57 mice resulted in micromolar concentrations at 30 min within brain parenchyma. After 3 months of intranasal DFO treatment, 2.4 mg three times per week, 48-week-old APP/PS1 mice had significantly reduced escape latencies in Morris water maze compared to vehicle-treated mice. This is the first report that intranasal DFO improves spatial memory in a mouse model of Alzheimer's disease and demonstrates that intranasal DFO reaches the brain in therapeutic doses.
ABSTRACT
This school-based randomized controlled trial tested the efficacy of 2 expressive writing interventions among youth living in high-violence urban neighborhoods. Seventeen classrooms (n = 258 seventh graders; 55% female; 91% African American/Black) from 3 public schools were randomized to 3 conditions in which they wrote 8 times about a nonemotional topic (control condition) or about experiencing and witnessing violence following either a standard or an enhanced expressive writing protocol. Outcomes were assessed 1 month prior and 2 and 6 months postintervention and included teacher-rated emotional lability and aggressive behavior and child-rated physical aggression. Intent-to-treat, mixed-model analyses controlled for preintervention measures of outcomes, sex, race, and family structure. At 2 months postintervention, relative to controls, students in the standard expressive writing condition had lower levels of teacher-rated aggression and lability (d = -.48). The beneficial effects of the writing interventions on aggression and lability were stronger at higher levels of community violence exposure.
Subject(s)
Aggression/psychology , Behavior Therapy , Emotions , Social Environment , Writing , Adolescent , Adolescent Behavior/psychology , Female , Humans , Male , Risk-Taking , Schools , Treatment Outcome , Urban Population , Violence/psychologyABSTRACT
Intranasal administration is emerging as a reliable and non-invasive method to bypass the blood-brain barrier and deliver drugs to the brain. This approach has been primarily used to explore therapeutic avenues for neurological diseases. However, intranasal administration could also be used to create animal models of brain disease. Beta-amyloid peptide (Aß) accumulation is a key feature of Alzheimer's disease (AD), and the most common models of AD are transgenic mice expressing mutant human genes linked to familial AD. An alternative model of amyloidosis utilizes intracerebroventricular infusion of thiorphan or phosphoramidon to block the activity of key Aß degrading enzymes (NEP, NEP2) resulting in accumulation of Aß. Here, we demonstrate that intranasal administration of phosphoramidon produces significantly elevated cerebral Aß levels in wild-type mice. Furthermore, intranasal phosphoramidon administration in double knockout mice lacking NEP and NEP2 also showed increased levels of Aß(40). These data show that intranasal delivery of drugs can be used to model AD and suggest that other phosphoramidon-sensitive peptidases are degrading Aß in NEP/NEP2-deficient mice.
Subject(s)
Administration, Intranasal , Amyloid beta-Peptides/metabolism , Glycopeptides/administration & dosage , Glycopeptides/pharmacology , Neprilysin/deficiency , Protease Inhibitors/administration & dosage , Protease Inhibitors/pharmacology , Alzheimer Disease/drug therapy , Alzheimer Disease/genetics , Amyloid beta-Peptides/genetics , Animals , Disease Models, Animal , Humans , Mice , Mice, Knockout , Neprilysin/geneticsABSTRACT
A Center for Academic Excellence in Youth Violence Prevention was established in 1999 at Virginia Commonwealth University, in the small city of Richmond, Virginia. The social context of Richmond provides many challenges and assets for preventing youth violence, including high levels of youth exposure to violence and exemplary role models for resiliency. In this paper, the conceptual framework used to guide Center activities is explained first, followed by an accounting of the initial activities for developing a community mobilization process. Next, examples are presented of how the core theme of "Strengthening the Voices of Stakeholders" was implemented at the levels of grassroots/taxpayer, organizations, and systems/policy. A university policy strategy for involving more sectors of the University in community partnerships to prevent youth violence and promote positive early childhood development is then described. The paper closes with an assessment of the mobilization efforts to date and a sketch of new plans for the future.
Subject(s)
Community Networks/organization & administration , Program Development , Urban Population , Violence/prevention & control , Adolescent , Adult , Cities , Evidence-Based Medicine , Humans , Needs Assessment , Schools , VirginiaABSTRACT
Although injury is the leading cause of death for Americans aged 40 and under, curricula in U.S. Schools of Public Health rarely include training on injury prevention or control. Domestically and internationally, when the topic of injury is addressed, the focus is often on unintentional injuries. Yet intentional injuries from violence and self-harm (apart from acts of war and terrorism) and the acute and chronic health problems associated with them take a large and often hidden toll on individuals, families, and communities worldwide. Adequate education on the prevention of violence and suicide by teenagers remains missing from public health and medical training. Public health and medical practitioners are confronted by violence-related injury but are provided little formal education on youth violence or suicide, effective responses, or prevention. Adolescents' involvement in violence remains a serious public health problem. Involvement in aggression and self-harm by adolescents leaves them at immediate risk of injury and often has ongoing and negative effects on future development, involvement in community and family life, and risk of morbidity and mortality for self and others. Public health practitioners are at the nexus of health care and service provision at local, state, federal, and multinational levels, and are well suited to provide training and technical assistance on youth violence prevention across disciplines and settings. In this article, training resources, opportunities, and strategies for prevention of the high prevalence of youth violence and suicide in the U.S. are discussed and recommendations for a new public health training initiative are outlined.
Subject(s)
Curriculum , Juvenile Delinquency/prevention & control , Public Health/education , Suicide Prevention , Violence/prevention & control , Adolescent , Adolescent Behavior , Humans , Program Development , Self-Injurious Behavior/prevention & control , United States , Wounds and Injuries/prevention & controlABSTRACT
A six-module curriculum on youth violence prevention, The Epidemiology and Prevention of Intentional Injury, was developed for inclusion in a Virginia Commonwealth University Department of Epidemiology and Community Health graduate course for public health students. The content of the curriculum was determined by reviewing key literature and the consensus group reports of experts in the area of youth violence prevention and prevention research more generally. A rationale of course content related to youth violence prevention and an overview of course content, objectives, required reading, and assignments are provided. Suggestions are made for possible adaptation of this youth violence prevention curriculum into public health courses other than intentional injury.
Subject(s)
Curriculum , Juvenile Delinquency/prevention & control , Public Health/education , Violence/prevention & control , Adolescent , Adolescent Behavior , Child , Child Behavior , Consensus , Humans , Program Development , Schools, Public Health , VirginiaABSTRACT
Arachidonic acid (AA), released in response to muscarinic acetylcholine receptor (mAChR) stimulation, previously has been reported to function as a reversible feedback inhibitor of the mAChR. To determine if the effects of AA on binding to the mAChR are subtype specific and whether AA inhibits ligand binding to other G protein-coupled receptors (GPCRs), the effects of AA on ligand binding to the mAChR subtypes (M1, M2, M3, M4, and M5) and to the micro-opioid receptor, beta2-adrenergic receptor (beta2-AR), 5-hydroxytryptamine receptor (5-HTR), and nicotinic receptors were examined. AA was found to inhibit ligand binding to all mAChR subtypes, to the beta2-AR, the 5-HTR, and to the micro-opioid receptor. However, AA does not inhibit ligand binding to the nicotinic receptor, even at high concentrations of AA. Thus, AA inhibits several types of GPCRs, with 50% inhibition occurring at 3-25 MuM, whereas the nicotinic receptor, a non-GPCR, remains unaffected. Further research is needed to determine the mechanism by which AA inhibits GPCR function.
Subject(s)
Arachidonic Acid/metabolism , Receptors, Adrenergic, beta-2/metabolism , Receptors, G-Protein-Coupled/metabolism , Receptors, Muscarinic/metabolism , Receptors, Opioid, mu/metabolism , Receptors, Serotonin/metabolism , Adrenergic beta-Antagonists/chemistry , Adrenergic beta-Antagonists/metabolism , Animals , Arachidonic Acid/chemistry , Dihydroalprenolol/chemistry , Dihydroalprenolol/metabolism , Diprenorphine/chemistry , Diprenorphine/metabolism , Humans , Ligands , Molecular Structure , Muscarinic Antagonists/chemistry , Muscarinic Antagonists/metabolism , N-Methylscopolamine/chemistry , N-Methylscopolamine/metabolism , Narcotic Antagonists/chemistry , Narcotic Antagonists/metabolism , Parasympatholytics/chemistry , Parasympatholytics/metabolism , Protein Binding , Protein Isoforms/metabolism , Quinuclidinyl Benzilate/chemistry , Quinuclidinyl Benzilate/metabolism , Radioligand Assay , Serotonin/chemistry , Serotonin/metabolismABSTRACT
This paper describes the theoretical basis and content of the universal student component of the Guiding Responsibility and Expectations for Adolescents for Today and Tomorrow (GREAT) Schools and Families' middle school violence prevention program for changing school climate. The GREAT Student Program builds on and extends the content of the sixth grade Responding In Peaceful and Positive Ways (RIPP-6) social-cognitive violence prevention program through an expanded conceptual framework that focuses on changing school norms and explicitly incorporates cultural and contextual goals. The program consists of twenty 40-minute lessons taught by a trained facilitator on a weekly basis during the school day.
Subject(s)
Adolescent Behavior/psychology , Child Behavior/psychology , Primary Prevention/organization & administration , School Health Services/organization & administration , Violence/prevention & control , Adolescent , Child , Culture , Curriculum , Humans , Organizational Objectives , Program Development , Self Efficacy , Students/psychology , United StatesABSTRACT
PROBLEM: Pregnancy has been considered as a model of successfully controlled tissue invasion where trophoblast cells infiltrate the maternal decidua without being rejected or without destroying the tissue. In choriocarcinoma (CC) and hydatidiform mole (HM), a dysregulation of invasive (malignant/benign) trophoblast cells is present. Immunocompetent cells (IC) are known to be involved in rejection pathways of malignant cells and can also be identified in early pregnancy decidua. The aim of the present study was to identify the phenotype of IC in decidua of women with normal pregnancy (NP), CC and HM. METHODS: Immunocompetent cells were detected by immunohistochemistry in decidual tissue from first trimester NP (n = 10), CC (n = 12) and HM (n = 11) using antibodies against CD8+, CD3+, CD56+, CD68+ cell surface markers and mast cell tryptase (MCT). A scaled eye piece was used for cell counting to obtain semiquantitative results. Statistical analysis was performed using Wilcoxon rank/Mann-Whitney tests. RESULTS: We observed a significantly increased number of lymphocytes positive for CD8, CD3 and MCT positive granulocytes in CC and HM compared with the samples from NP (all P < or = 0.001). Lymphocytes positive for natural killer (NK) cell marker CD56 were significantly decreased in CC and HM versus NP (P < or = 0.001). The number of CD68 positive cells (macrophages) were not significantly different among the tissue pools. CONCLUSION: The increase of CD8/CD3 T cells and mast cells in CC and HM and the decrease of CD56 cells, compared with NP, suggests the necessity of a balance between T and NK cells in controlling trophoblast invasion.