Study on the Organoleptic Intensity Scale for Measuring Oral Malodor

The 0–5 organoleptic scale is used widely in breath research and in trials to measure the efficacy of anti-odor agents. However, the precise relationship between odor scores and gas concentrations of target odorants is unknown. The purpose of this study was to relate mean organoleptic scores from odor judges (n = 7) for pure odorants (n = 8) representative of those found in oral malodor. Judges used a common 0–5 scale to report the odor intensity of sample sets in random order of concentration. Regression analysis of data showed that odor score was proportional to the log concentration of odorant, and comparison of slopes showed H2S to be the most significant in terms of odor power. Detection thresholds (mol.dm−3) were: Skatole (7.2 × 10−13) < methylmercaptan (1.0 × 10−11) < trimethylamine (1.8 × 10−11) < isovalerate (1.8 × 10−11) < butyrate (2.3 × 10−10) < hydrogen sulphide (6.4 × 10−10) < putrescine (9.1 × 10−10) < dimethyl disulphide (5.9 × 10−8). The study demonstrates the exponential nature of the olfactory response and shows that any single compound’s contribution to malodor depends on odor power and threshold in addition to concentration.

Homeostatic control of conjunctival mucosal goblet cells by NKT-derived IL-13

Although the effects of the interleukin 13 (IL-13) on goblet cell (GC) hyperplasia have been studied in the gut and respiratory tracts, its effect on regulating conjunctival GC has not been explored. The purpose of this study was to determine the major IL-13-producing cell type and the role of IL-13 in GC homeostasis in normal murine conjunctiva. Using isolating techniques, we identified natural killer (NK)/natural killer T (NKT) cells as the main producers of IL-13. We also observed that IL-13 knockout (KO) and signal transducer and activator of transcription 6 knockout (STAT6KO) mice had a lower number of periodic acid Schiff (PAS)+GCs. We observed that desiccating stress (DS) decreases NK population, GCs, and IL-13, whereas it increases interferon-γ (IFN-γ) mRNA in conjunctiva. Cyclosporine A treatment during DS maintained the number of NK/NKT cells in the conjunctiva, increased IL-13 mRNA in NK+ cells, and decreased IFN-γ and IL-17A mRNA transcripts in NK+ and NK- populations. C57BL/6 mice chronically depleted of NK/NKT cells, as well as NKT cell-deficient RAG1KO and CD1dKO mice, had fewer filled GCs than their wild-type counterparts. NK depletion in CD1dKO mice had no further effect on the number of PAS+ cells. Taken together, these findings indicate that NKT cells are major sources of IL-13 in the conjunctival mucosa that regulates GC homeostasis.

Multistrain influenza protection induced by a nanoparticulate mucosal immunotherapeutic

All commercial influenza vaccines elicit antibody responses that protect against seasonal infection, but this approach is limited by the need for annual vaccine reformulation that precludes efficient responses against epidemic and pandemic disease. In this study we describe a novel vaccination approach in which a nanoparticulate, liposome-based agent containing short, highly conserved influenza-derived peptides is delivered to the respiratory tract to elicit potent innate and selective T cell-based adaptive immune responses. Prepared without virus-specific peptides, mucosal immunostimulatory therapeutic (MIT) provided robust, but short-lived, protection against multiple, highly lethal strains of influenza in mice of diverse genetic backgrounds. MIT prepared with three highly conserved epitopes that elicited virus-specific memory T-cell responses but not neutralizing antibodies, termed MITpep, provided equivalent, but more durable, protection relative to MIT. Alveolar macrophages were more important than dendritic cells in determining the protective efficacy of MIT, which induced both canonical and non-canonical antiviral immune pathways. Through activation of airway mucosal innate and highly specific T-cell responses, MIT and MITpep represent novel approaches to antiviral protection that offer the possibility of universal protection against epidemic and pandemic influenza.

The development of effector T cell subsets in murine Leishmania major infection

Leishmania major infection has proven an exceptional model for CD4+ subset development in inbred mice. Most strains contain infection coincident with the appearance of T helper 1 (Th1) cells that produce gamma-interferon (IFN-gamma) required for macrophage activation. In contrast, mice on the BALB background are unable to control infection due to the development of Th2 cells that produce counter-regulatory cytokines, particularly interleukin 4 (IL-4), capable of abrogating the effects of IFN-gamma. Selective gene disruption studies in mice have illustrated critical components of the host response to L. major. Mice deficient in beta 2 microglobulin, which have no major histocompatibility complex (MHC) class I or CD8+ T cells, control infection as well as wild-type mice, whereas mice deficient in MHC class II (and CD4+ T cells) suffer fatal infection. Mice with disruption of the gene coding IFN-gamma are also incapable of containing infection, reflecting absolute requirements for this cytokine. A number of interventions have been demonstrated to abrogate Th2 cell development in BALB mice, enabling these mice to control infection. Each of these--IL-12, anti-IL-4, anti-IL-2, anti-CD4 and CTLA4-Ig--has in common the capacity to make IL-4 rate limiting at the time of CD4+ cell priming.

Pelvi-calyceal height, a predictor of success when treating lower pole stones with extracorporeal shockwave lithotripsy

Extra corporeal shockwave lithotripsy (ESWL) is the treatment of choice for the majority of renal stones, however, it has the lowest success rate in complete clearance of stones located in the lower pole. We assess whether pelvi-calyceal height is a useful measurement in predicting successful stone clearance from the lower pole. A total of 105 patients with a solitary lower pole calculus of less than 20 mm treated with ESWL were reviewed. Stone size, location and pelvi-calyceal height were measured by intravenous urogram. Success was defined as complete stone clearance. Fifty-four patients (51.4%) had successful treatments, with the remaining 51 (48.6%) having incomplete stone clearance (including two patients in whom treatment had no effect). There was a statistically significant difference (P<0.0001) in pelvi-calyceal height between the two groups. Mean pelvi-calyceal height in patients with complete stone clearance was 15.1 mm (SD=3.9) compared with 22.9 mm (SD=5.2) for those with incomplete clearance. Pelvi-calyceal height is a useful predictor of success when treating lower pole renal stones with ESWL.

Epidemiology of paediatric renal stone disease in the UK

BACKGROUND

The previous epidemiological study of paediatric nephrolithiasis in Britain was conducted more than 30 years ago.

AIMS

To examine the presenting features, predisposing factors, and treatment strategies used in paediatric stones presenting to a British centre over the past five years.

METHODS

A total of 121 children presented with a urinary tract renal stone, to one adult and one paediatric centre, over a five year period (1997-2001). All children were reviewed in a dedicated stone clinic and had a full infective and metabolic stone investigative work up. Treatment was assessed by retrospective hospital note review.

RESULTS

A metabolic abnormality was found in 44% of children, 30% were classified as infective, and 26% idiopathic. Bilateral stones on presentation occurred in 26% of the metabolic group compared to 12% in the infective/idiopathic group (odds ratio 2.7, 95% CI 1.03 to 7.02). Coexisting urinary tract infection was common (49%) in the metabolic group. Surgically, minimally invasive techniques (lithotripsy, percutaneous nephrolithotomy, and endoscopy) were used in 68% of patients.

CONCLUSIONS

There has been a shift in the epidemiology of paediatric renal stone disease in the UK over the past 30 years. Underlying metabolic causes are now the most common but can be masked by coexisting urinary tract infection. Treatment has progressed, especially surgically, with sophisticated minimally invasive techniques now employed. All children with renal stones should have a metabolic screen.

Antimicrobial photodynamic therapy: assessment of genotoxic effects on keratinocytes in vitro

BACKGROUND

Work has shown that cutaneous microbial species associated with skin conditions of microbial aetiology are susceptible to killing by antimicrobial photodynamic therapy (APDT) using visible light and methylene blue.

OBJECTIVES

To evaluate immediate and delayed genotoxicity of APDT on keratinocytes in vitro.

METHODS

A combination of methylene blue (100 microg mL(-1)) and visible light (42 mW cm(-2)), as used in studies of microbe and keratinocyte cytotoxicity, was employed to test a human keratinocyte cell line (H103) for genotoxic damage by comet assay.

RESULTS

The comet assay was able to detect genotoxic damage in H2O2-treated keratinocytes (positive control). APDT did not cause either immediate or delayed genotoxic damage in keratinocytes following APDT of up to 180 min.

CONCLUSIONS

APDT sufficient to reduce microbes by seven log cycles showed no detectable genotoxic effects on keratinocytes. APDT applied in vivo may represent a useful low-risk alternative to conventional antimicrobial treatment in dermatology.

Cytotoxic effects of antimicrobial photodynamic therapy on keratinocytes in vitro

BACKGROUND

Previous work has shown that cutaneous microbial species associated with skin conditions of microbial aetiology are susceptible to killing by photodynamic therapy (PDT) using visible light and methylene blue. Antimicrobial PDT (APDT) in vivo would require a therapeutic regimen where bacteria could be killed without damaging adjacent tissue.

OBJECTIVES

To study keratinocyte killing in vitro using APDT.

METHODS

We used a combination of methylene blue (100 microg mL(-1)) and visible light (42 mW cm(-2)), previously used for microbial killing, to study cytotoxic effects on keratinocytes. Kill rates and subsequent D-values were determined against a human keratinocyte cell line (H103) using trypan blue and neutral red dye viability tests.

RESULTS

The kill rates for keratinocytes were exponential over the 90- and 180-min period of the experiment for neutral red and trypan blue, respectively. The corresponding D-values were shown to be 198 and 205 min using trypan blue exclusion and neutral red uptake viability tests, respectively.

CONCLUSIONS

The kill rates for keratinocytes were 18-200-fold slower than those previously determined for cutaneous microbial species, suggesting that in vivo, APDT sufficient to reduce microbes by seven log cycles would have little cytotoxic effect on keratinocytes. This approach may offer a safe alternative to conventional antimicrobial treatment.

Cutting edge: the absence of C3 demonstrates a role for complement in Th2 effector functions in a murine model of pulmonary allergy

Asthma is a chronic disease of the lung resulting from airway obstruction. Although the initiating causes are not entirely clear, the airway inflammation in asthma is associated with Th2 lymphocytes and their cytokines, particularly IL-4, which play a prominent role in this disease by regulating airway hyperresponsiveness, eosinophil activation, and IgE synthesis. Historically, complement was not thought to contribute to the pathogenesis of asthma. However, using C3-deficient mice in an allergen-induced model of pulmonary allergy, we demonstrate that complement may impact key features of this disease. When challenged with allergen, mice deficient in C3 exhibit diminished airway hyperresponsiveness and lung eosinophilia. Furthermore, these mice also have dramatically reduced numbers of IL-4-producing cells and attenuated Ag-specific IgE and IgG1 responses. Collectively, these results demonstrate that C3-deficient mice have significantly altered allergic lung responses and indicate a role for the complement system in promoting Th2 effector functions in asthma.

Selective aspects of the insulin resistance syndrome

There is increasing recognition of new features in the insulin resistance syndrome and its association with new disease states or treatment modalities. Recent additions to the list of features in the insulin resistance syndrome include elevated non-esterified fatty acids, abnormalities in visceral fat metabolism, elevated uric acid, elevated hematocrit, endothelial dysfunction, abnormalities in glucocorticoids, and differences in the phenotypic expression of the syndrome between men and women. A critical factor that may be inherent in the syndrome is the distribution and metabolism of visceral fat. This finding is also accompanied by the recognition of the role of non-esterified fatty acids as a cause of many of the risk factors in the insulin resistance syndrome. Elevated non-esterified fatty acids contribute to hypertension, glucose intolerance and increased arteriosclerosis. Elevated cortisol levels and disrupted metabolism, as well as abnormalities in the hypothalamic-pituitary-adrenal axis are seen in the insulin resistance syndrome. In women, adipose cells express fewer glucocorticoid receptors and less of the enzyme that metabolizes cortisol, 11beta-hydroxysteroid dehydrogenase. Several inflammatory factors such as tumor necrosis factor-alpha may be an etiologic link in the risk found in the insulin resistance syndrome. Certain cases of the syndrome appear to be related to specific drug therapies (steroids, immunosuppressive agents and antiretroviral agents), as seen in transplant patients and HIV-infected individuals.

Sex-related differences in the insulin resistance syndrome

In the insulin resistance (IR) syndrome, sex-specific differences have been reported. First, hypertension more often correlates with hyperinsulinemia in women than in men with the IR syndrome. In addition, salt sensitivity of blood pressure appears to be independent of the activity of the renin-angiotensin system in women, whereas in men there is a strong correlation between the two variables. Secondly, the dyslipidemia found in women with the IR syndrome is characterized by less postprandial plasma insulin, triglycerides, and fatty acid response to a standardized meal. However, this sex difference in lipids disappears after correction for visceral fat mass. Fat physiology and biochemistry differ between the two sexes. In women, adipose cells express less glucocorticoid receptors and less 11beta-hydroxysteroid dehydrogenase. In women visceral fat accumulation appears to be a constant feature of the IR syndrome but in men the syndrome can be present without central obesity. Lastly, during the reproductive years of women, the IR syndrome, such as in pre-eclampsia, may cause fetal growth retardation that has been proposed together with maternal malnutrition to be at the origin of the increased risk for impaired glucose tolerance, hyperinsulinemia, and hypertension in adult life. This gives yet another dimension to this disease in women since in essence they may ultimately transmit this syndrome to both sexes.

A study to assess the plaque inhibitory action of a new zinc citrate toothpaste formulation

BACKGROUND, AIMS

Zinc-citrate-containing toothpastes have previously been suggested to be of value at inhibiting plaque and gingival inflammation. Present formulations have included triclosan which is thought to contribute major antibacterial/antiplaque effects. Alternative antimicrobial agents and other ingredients such as oils could help to produce equally effective formulations. The aim of this study was to determine whether zinc citrate toothpastes containing bromochlorophene and a triglyceride oil (1% and 8%) could inhibit de novo plaque formation.

METHODS

Toothpaste slurry rinses were used over a 96-h period by 24 volunteers, whilst omitting all other oral hygiene procedures. For comparative purposes, a conventional commercial fluoride control toothpaste was also used in this triple cross-over double blind study.

RESULTS

After 24 and 48 h, there were no statistically significant differences in plaque between the 2 test pastes and the control paste, whether assessed using a plaque index or plaque area. After 96 h, however, a significant reduction in plaque score of 10.6% and 24.2%) in plaque area (both p < 0.001) was found for the zinc citrate/1% oil toothpaste compared to the control paste. In addition, at 96 h, the 8% oil toothpaste significantly reduced plaque score compared to the control paste by 4.3% (p = 0.029).

CONCLUSIONS

These findings would appear to warrant further investigation into the potential value of the zinc citrate/bromochlorophene/triglyceride formulation at inhibiting both plaque and gingival inflammation.

The management of paediatric urolithiasis

OBJECTIVE

To evaluate the efficacy and safety of the management of paediatric urolithiasis by extracorporeal shock wave lithotripsy (ESWL), endoscopic ureterolithotomy, percutaneous nephrolithotomy (PCNL) and open nephrolithotomy.

PATIENTS AND METHODS

In a 3-year period (1997-1999), 59 children were treated for urolithiasis and underwent a total of 79 procedures. Thirty-two ESWL sessions were performed in 23 children (mean age 7.4 years, median 6.0). PCNL was undertaken in 30 renal units in 25 children (mean age 6.4 years, median 4.0). Eight patients (mean age 7.8 years, median 5) underwent 17 ureteroscopic procedures, six of which involved the use of a holmium laser. Three children with staghorn calculi underwent open nephrolithotomy under conditions of renal ischaemia and hypothermia.

RESULTS

Of the 23 children treated using ESWL, 21 (91%) became stone-free; 17 underwent one ESWL session (74%), three had two sessions and three (13%) had three sessions. All eight patients who underwent ureteroscopy became stone-free. Four patients in whom the stone could not be reached by ureteroscopy initially had a JJ stent inserted, and the stone and stent subsequently removed. Stones were cleared using PCNL in 27 of 30 renal units (90%); three patients who had residual stone fragments were rendered stone-free by ESWL. Two of three children undergoing open nephrolithotomy were stone-free after surgery and the remaining one rendered stone-free with ESWL. Metabolic evaluation showed that 25 of 45 children (55%) had a urinary infection, eight (18%) had hyperoxaluria, three (7%) had hypercalciuria, two (4%) had cystinuria, and no identifiable cause was found in seven (16%). Treatment by a single modality rendered 52 of the 59 children (88%) stone-free; when the different modalities were combined, 57 of 59 patients (97%) were cleared of their stones.

CONCLUSIONS

Technological advances in ESWL, ureteroscopy and PCNL have had a significant effect on the management of urolithiasis in children, allowing a safe and successful outcome. The comprehensive care of children with urolithiasis should include a full metabolic evaluation. Anatomical anomalies contribute to the complexity of many cases, necessitating a close liaison between adult and paediatric urologists, nephrologists and radiologists to optimize stone management in children.

Baseline airway hyperreactivity in A/J mice is not mediated by cells of the adaptive immune system

Human asthma is characterized by increased airway hyperreactivity to a variety of bronchoconstricting agents. Aberrant type 2 immune responses in the lung have been associated with airway hyperreactivity in both human asthma and in murine models of allergic airways disease. Despite their intrinsically elevated basal airway reactivity to smooth muscle constricting agents, A/J mice demonstrated no inherent inflammatory cell infiltration nor elevation of type 2 cytokines in the lung. Crossed bone marrow reconstitution experiments between A/J and MHC congenic B10.A mice revealed enhanced airway reactivity only in A/J recipients, irrespective of whether they had been reconstituted with A/J or B10. A hemopoietic cells. Further, A/J-derived bone marrow cells did not affect the reactivity of B10.A recipients. Although mice on RAG-deficient and IL-4-deficient backgrounds demonstrate substantial abrogation of allergen-induced airway hyperreactivity, these gene deletions had no impact on the elevated baseline reactivity when backcrossed onto A/J mice. Thus, in these mice, basal airway hyperreactivity is maintained independently of type 2 immunity induced by allergens.

Protection from vascular risk in diabetic hypertension

Diabetes mellitus is a metabolic disorder characterized by hyperglycemia and associated with a high incidence of complications affecting both the microvascular and the macrovascular systems. Macrovascular disease affects the coronary arteries, the cerebral vessels, and the large peripheral arteries of the lower extremities. Microangiopathy affects the kidneys, eyes, and nerves. Both forms of complication are major causes of death and disability in diabetes. The precise pathophysiology of these vascular complications is becoming better understood, but specific treatment and prevention remain complex.

Airway inflammation and remodeling in asthma

An important advance in our understanding of the pathophysiology of asthma has been the discovery that airway inflammation is not confined to severe asthma but also characterizes mild and moderate asthma. Inflammation in asthma may be the result of a peculiar type of lymphocytic inflammation whereby Th2 lymphocytes secrete cytokines that orchestrate cellular inflammation and promote airway hyperresponsiveness. The term "airway remodeling" in asthma refers to structural changes that occur in conjunction with, or because of, chronic airway inflammation. Airway remodeling results in alterations in the airway epithelium, lamina propria, and submucosa, leading to thickening of the airway wall. The consequences of airway remodeling in asthma may include incompletely reversible airway narrowing, bronchial hyperresponsivenesss, airway edema, and mucus hypersecretion. Airway remodeling in asthma thus may predispose persons with asthma to asthma exacerbations and even death from airway obstruction caused by smooth muscle contraction, airway edema, and mucus plugging. Although much has been learned in the past 25 years about the pathophysiology of airway inflammation and airway remodeling in asthma, important questions remain about the relation between airway inflammation and remodeling, the natural history of airway remodeling, and the effects of current asthma treatments on remodeled airways.

IL-13 in allergy: home at last

The immune response to allergic challenge is thought to include important effects mediated by cytokines. Of considerable interest to immunologists and parasitologists is the distinction between two closely related cytokines, IL-4 and IL-13. Although overlapping functions are inevitable, studies over the past year reveal a distinct role for IL-13 in mediating the physiologic response to a diverse array of allergens and parasites.

Induction and regulation of the IgE response

Immunoglobulin E (IgE) is believed to be one of the major mediators of immediate hypersensitivity reactions that underlie atopic conditions such as urticaria, seasonal allergy, asthma and anaphylaxis. Factors that control IgE production are therefore essential to the pathogenesis of these important afflictions. But a complete understanding of this topic is lacking, while new data have raised questions regarding the precise role of IgE in atopic disease. Evolving concepts of IgE production and elimination are likely to clarify the importance of IgE in health and disease.

Obesity, hypertension, and sympathetic nervous system activity

Several epidemiologic studies have shown that obesity represents an independent risk factor for the development of cardiovascular diseases, including hypertension, myocardial ischemic disease, and cardiac arrhythmias. One of the most appealing concepts in obesity-related hypertension is that a specific etiology can be identified. There is now substantial evidence that human obesity is characterized by abnormalities in sympathetic cardiovascular control. The application of sensitive techniques to assess sympathetic nervous system (SNS) activity in humans, including catecholamine levels, norepinephrine (NE) spillover techniques, and microneurography have furthered this concept. Catecholamine levels in obesity have been conflicting, with high, normal, and low levels reported. However, studies examining weight loss have found that the fall in blood pressure (BP) was highly correlated with reductions in plasma NE. Examination of NE spillover in obesity has shown regional overactivity in the kidneys. High renal SNS activity could lead to sodium retention and abnormal glomerular hemodynamics that could raise BP. Microneurography, which determines muscle sympathetic outflow, has shown consistent elevation in obesity, but no difference between normotensive and hypertensive obesity. However, the hyperinsulinemia of obesity may act in concert with the SNS to elevate BP, as the combination of the two seems to produce vascular constriction. Leptin also has several cardiovascular actions that may contribute to BP regulation. Epidemiologic studies also found that SNS activity predicts hypertension in obese subjects.

Assessment of acrylic bone cement as a local delivery vehicle for the application of non-steroidal anti-inflammatory drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) have been widely used to reduce the inflammation and pain in patients suffering from arthritis. There is a possible use for these drugs in the treatment of inflammation associated with periodontitis. However, the propensity of NSAIDs to cause serious side effects, including gastrointestinal bleeding, has reduced their usefulness. The local application of NSAIDs can avoid these side effects by delivering low doses of drug directly to the affected site. Three NSAIDs (indomethacin, tolmetin and mefenamic acid) were incorporated into polymethylmethacrylate bone cement (PM MA) strips in a range of concentrations and their cytotoxicity, pattern of drug release and ability to suppress elevated levels of prostaglandin E2 (PGE2) in cultured human periodontal ligament fibroblasts (HPLF) assessed. The strips released between 10 and 30% of the total incorporated drug over 7 days, with the highest levels released by strips containing 20% w/w of drug. Strips containing 20% indomethacin and mefenamic acid released in excess of toxic levels in the first 24 h. Strips containing 20, 10 and 5% w/w NSAID significantly (P < 0.05) reduced the level of PGE2 expression by E. coli lipopolysaccharide (LPS) challenged cells, with only the 20% mefenamic acid strip performing significantly better than the other drugs. We conclude that local delivery of NSAIDs using PMMA as a sustained release vehicle is a possible additional tool in the treatment of periodontitis.

Requirements for allergen-induced airway hyperreactivity in T and B cell-deficient mice

BACKGROUND

The pathogenesis of asthma is believed to reflect antigen-induced airway inflammation leading to the recruitment of eosinophils and activation of mast cells through cell-associated IgE. Controversies persist however, regarding the relative importance of different pathogenic cells and effector molecules.

MATERIALS AND METHODS

A variety of gene-targeted mice were examined for the induction of cholinergic airway hyperresponsiveness (AH), allergic airway inflammation, mucus production, and serum IgE reactivity following intratracheal challenge with a potent allergen. AH was determined using whole-body plethysmography following acetylcholine challenge. Where possible, results were confirmed using neutralizing antibodies and cell-specific reconstitution of immune deficient mice.

RESULTS

T and B cell-deficient, recombinase-activating-gene-deficient mice (RAG -/-) failed to develop significant allergic inflammation and AH following allergen challenge. Reconstitution of RAG -/- mice with CD4+ T cells alone was sufficient to restore allergen-induced AH, allergic inflammation, and goblet cell hyperplasia, but not IgE reactivity. Sensitized B cell-deficient mice also developed airway hyperreactivity and lung inflammation comparable to that of wild-type animals, confirming that antibodies were dispensable. Treatment with neutralizing anti-IL-4 antibody or sensitization of IL-4-deficient mice resulted in loss of airway hyperreactivity, whereas treatment with anti-IL-5 antibody or sensitization of IL-5-deficient mice had no effect.

CONCLUSIONS

In mice, CD4+ T cells are alone sufficient to mediate many of the pathognomonic changes that occur in human asthma by a mechanism dependent upon IL-4, but independent of IL-5, IgE, or both. Clarification of the role played by CD4+ T cells is likely to stimulate important therapeutic advances in treatment of asthma.

IL-10 improves lung injury and survival in Pseudomonas aeruginosa pneumonia

Pseudomonas aeruginosa is the most frequent Gram-negative pathogen causing nosocomial pneumonia. Four different strains of P. aeruginosa (including three isogenic transposon mutants) were utilized in experiments in mice to characterize the specific patterns of cytokine generation in response to bacterial products and cytotoxicity. Intratracheal instillation of any of the strains led to the up-regulation of IL-1beta, IL-6, and TNF-alpha mRNA. Instillation of the cytotoxic strains (PA103, PA103tox::omega) led to IL-10 mRNA up-regulation in the lungs and increased concentrations of IL-10 in the blood. In contrast, the instillation of the noncytotoxic strains (PA01, PA103exsA::omega) did not lead to an increase in IL-10 mRNA in the lungs or to an increase of IL-10 concentration in blood. IL-10 production appears to be a response to either cellular injury or to specific cytotoxic exoproducts produced by the bacteria. The systemic administration of rIL-10 significantly decreased the lung injury and the mortality in mice who had received the cytotoxic strains. The improvement in survival induced by administration of rIL-10 required the concomitant presence of IFN-gamma, as blockade of IFN-gamma with a neutralizing Ab led to 100% mortality, despite the administration of rIL-10. These results suggest that IL-10 is produced in response to specific bacterial products and that there is a potential role for IL-10 in the treatment of cytotoxic P. aeruginosa pneumonia.

IL-10 improves lung injury and survival in Pseudomonas aeruginosa pneumonia

Pseudomonas aeruginosa is the most frequent Gram-negative pathogen causing nosocomial pneumonia. Four different strains of P. aeruginosa (including three isogenic transposon mutants) were utilized in experiments in mice to characterize the specific patterns of cytokine generation in response to bacterial products and cytotoxicity. Intratracheal instillation of any of the strains led to the up-regulation of IL-1beta, IL-6, and TNF-alpha mRNA. Instillation of the cytotoxic strains (PA103, PA103tox::omega) led to IL-10 mRNA up-regulation in the lungs and increased concentrations of IL-10 in the blood. In contrast, the instillation of the noncytotoxic strains (PA01, PA103exsA::omega) did not lead to an increase in IL-10 mRNA in the lungs or to an increase of IL-10 concentration in blood. IL-10 production appears to be a response to either cellular injury or to specific cytotoxic exoproducts produced by the bacteria. The systemic administration of rIL-10 significantly decreased the lung injury and the mortality in mice who had received the cytotoxic strains. The improvement in survival induced by administration of rIL-10 required the concomitant presence of IFN-gamma, as blockade of IFN-gamma with a neutralizing Ab led to 100% mortality, despite the administration of rIL-10. These results suggest that IL-10 is produced in response to specific bacterial products and that there is a potential role for IL-10 in the treatment of cytotoxic P. aeruginosa pneumonia.

Assessment of operative risk for patients with advanced lung disease

Increasingly, patients with advanced lung disease are being offered operative procedures. The assessment of the perioperative risk of these patients must include not only the assessment of their lung disease, but the assessment of the patient's cardiovascular disease, their age, and their other medical problems. Knowledge of the stress of particular surgical procedures is also of importance in risk assessment, and is addressed in this article.

Interleukin-10 is a natural suppressor of cytokine production and inflammation in a murine model of allergic bronchopulmonary aspergillosis

We have used interleukin-10 (IL-10) gene knockout mice (IL-10-/-) to examine the role of endogenous IL-10 in allergic lung responses to Aspergillus fumigatus Ag. In vitro restimulated lung cells from sensitized IL-10-/- mice produced exaggerated amounts of IL-4, IL-5, and interferon-gamma (IFN-gamma) compared with wild-type (WT) lung cells. In vivo, the significance of IL-10 in regulating responses to repeated A. fumigatus inhalation was strikingly revealed in IL-10-/- outbred mice that had a 50-60% mortality rate, while mortality was rare in similarly treated WT mice. Furthermore, IL-10-/- outbred mice exhibited exaggerated airway inflammation and heightened levels of IL-5 and IFN-gamma in bronchoalveolar lavage (BAL) fluids. In contrast, the magnitude of the allergic lung response was similar in intranasally (i.n.) sensitized IL-10-/- and wild-type mice from a different strain (C57BL/6). Using a different route of priming (intraperitoneal) followed by one i.n. challenge we found that IL-10-/- C57BL/6 mice had heightened eosinophilic airway inflammation, BAL-IL-5 levels, and numbers of alphabetaT cells in the lung tissues compared with WT mice. We conclude that IL-10 can suppress inflammatory Th2-like lung responses as well as Th1-like responses given the constraints of genetic background and route of priming.

Beta 2-microglobulin-dependent NK1.1+ T cells are not essential for T helper cell 2 immune responses

A number of investigations have established the critical role of interleukin 4 (IL-4) in mediating the development of T helper (Th)2 effector cells in vitro and in vivo. Despite intensive study, the origin of the IL-4 required for Th2 priming and differentiation remains unclear. Natural killer (NK)1.1+ alpha/beta T cell receptor+ T(NT) cells, a unique lineage of cells capable of producing large amounts of IL-4 after activation in vivo, are important candidates for directing Th2 priming. These cells are selected by the nonpolymorphic major histocompatibility complex (MHC) class I molecule, CD1, and are deficient in beta 2-microglobulin (beta 2m)-null mice. We used beta 2m-deficient mice on both BALB/c and C57BL/6 backgrounds to examine their capacity to mount Th2 immune responses after challenge with a number of well-characterized antigens administered by a variety of routes. As assessed by immunization with protein antigen, infection with Leishmania major, embolization with eggs of Schistosoma mansoni, intestinal infection with Nippostrongylus brasiliensis, or induction of airway hyperreactivity to aerosolized antigen, beta 2m-deficient mice developed functional type 2 immune responses that were not substantially different than those in wild-type mice. Production of IL-4 and the generation of immunoglobulin E (IgE) and eosinophil responses were preserved as assessed by a variety of assays. Collectively, these results present a comprehensive analysis of type 2 immune responses in beta 2m-deficient mice, and indicate that beta 2m-dependent NT cells are not required for Th2 development in vivo.

Human placental cytotrophoblasts produce the immunosuppressive cytokine interleukin 10

The mechanism by which the mammalian mother accepts the implanting fetus as an allograft remains unexplained, but is likely to be the result of a combination of factors. Mononuclear cytotrophoblasts, the specialized fetal cells of the placenta that invade the uterus, play an important role. These cells express HLA-G, an unusual major histocompatibility complex class I-B molecule, and secrete cytokines and pregnancy-specific proteins that can regulate immune function. We investigated whether cytotrophoblasts secrete interleukin 10 (IL-10), a cytokine that potently inhibits alloresponses in mixed lymphocyte reactions. Cytotrophoblasts from all stages of pregnancy produced IL-10 in vitro, but neither placental fibroblasts nor choriocarcinoma (malignant trophoblast) cell lines did so. Spontaneous IL-10 production averaged 650, 853, and 992 pg/10(6) cells in the first, second, and third trimesters of pregnancy, respectively. IL-10 secretion dropped approximately 10-fold after the first 24 h of culture, and was paralleled by a decrease in messenger RNA. IL-10 messenger RNA was detected in biopsies of the placenta and the portion of the uterus that contains invasive cytotrophoblasts, suggesting that this cytokine is also produced in vivo. IL-10 secreted by cytotrophoblasts in vitro is bioactive, as determined by its ability to suppress interferon gamma production in an allogeneic mixed lymphocyte reaction. We conclude that human cytotrophoblast IL-10 may be an important factor that contributes to maternal tolerance of the allogeneic fetus.

Cytokine production by peripheral blood mononuclear cells in human coccidioidomycosis

The production and mRNA expression of the cytokines interferon-gamma (IFN-gamma) and interleukin (IL)-4, -10, and -12 by peripheral blood mononuclear cells (PBMC) after incubation with the coccidioidal antigen toluene spherule lysate (TSL) from various subjects were measured. The IFN-gamma concentration in PBMC supernatants incubated for 72 h from 8 subjects with disseminated coccidioidomycosis was significantly less than that from 7 healthy, coccidioidal-immune subjects (P = .015). No differences were seen among the subject groups in the concentrations of IL-4, -10, or -12. By use of competitive polymerase chain reaction, PBMC from subjects with disseminated coccidioidomycosis also expressed less mRNA for IFN-gamma and IL-12 than did cells from healthy, immune subjects. These data suggest that patients with disseminated coccidioidomycosis have a diminished T helper lymphocyte type 1 response.

Inactivation of the integrin beta 6 subunit gene reveals a role of epithelial integrins in regulating inflammation in the lung and skin

The integrin alpha v beta 6 is only expressed in epithelial cells. In healthy adult epithelia, this receptor is barely detectable, but expression is rapidly induced following epithelial injury. Mice homozygous for a null mutation in the gene encoding the beta 6 subunit had juvenile baldness associated with infiltration of macrophages into the skin, and accumulated activated lymphocytes around conducting airways in the lungs. Beta 6-/- mice also demonstrated airway hyperresponsiveness to acetylcholine, a hallmark feature of asthma. These results suggest that the epithelial integrin alpha v beta 6 participates in the modulation of epithelial inflammation. Genetic or acquired alterations in this integrin could thus contribute to the development of inflammatory diseases of epithelial organs, such as the lungs and skin.

Increased inward passive permeability in vitro to sodium in uraemic erythrocytes

1. We have reported a normal sodium (Na) pump, but decreased loop-diuretic-sensitive Na efflux in erythrocytes from patients with chronic renal failure on haemodialysis, suggesting a different mode of co-transport in uraemia. 2. The present work extends these findings and examines in vitro simultaneous unidirectional and radiolabelled Na and K fluxes through the Na/K/Cl co-transport and the Na/K pump in washed erythrocytes from seven subjects with chronic renal failure and seven controls. Erythrocyte cytosolic calcium was also examined. 3. Ouabain-sensitive 86Rb influx was similar in patients and controls (1.76 +/- 0.19 versus 1.72 +/- 0.13 mmol h-1 litre-1 of erythrocytes) as was ouabain-sensitive 22Na efflux (3.62 +/- 0.36 versus 4.04 +/- 0.39 mmol h-1 litre-1 of erythrocytes). 4. Bumetanide-sensitive 86Rb and 22Na influx and 22Na efflux were measured at three concentrations (4, 8 and 12 mmol/l) of external K. In chronic renal failure, mean bumetanide-sensitive 22Na efflux was decreased at all external K concentrations compared with controls, and at physiological concentrations (4 mmol/l) external K was lower than controls (0.14 +/- 0.01 versus 0.38 +/- 0.05 mmol h-1 litre-1 of erythrocytes, P < 0.01). Mean bumetanide-sensitive 86Rb influx was also reduced in chronic renal failure at all external K concentrations, and at 4 mmol/l external K was lower than controls (0.13 +/- 0.04 versus 0.34 +/- 0.04 mmol h-1 litre-1 of erythrocytes, P < 0.01). Conversely, bumetanide-sensitive 22Na influx was markedly increased at all external K levels in chronic renal failure, and at 4 mmol/l external K values were elevated compared with controls (0.64 +/- 0.18 versus 0.34 +/- 0.04 mmol h-1 litre-1 of erythrocytes, P < 0.001). The mean cytosolic calcium concentration was higher in erythrocytes in chronic renal failure than controls (134.4 +/- 8.6 versus 63.7 +/- 5.8 nmol/l, P < 0.001). 5. Thus, in washed erythrocytes incubated in artificial media there is a markedly increased ouabain-insensitive Na influx in subjects with chronic renal failure which might be explained in part by the higher levels of cytosolic calcium. In vivo, this cell defect combined with suppression of the Na/K pump could lead to intracellular Na accumulation and play a role in uraemic complications.

Glucose and insulin metabolism in hypertension

Individuals with abnormal glucose and insulin metabolism have a higher incidence of hypertension, and recent interest has focused on the fact that patients with untreated essential hypertension have higher than normal plasma insulin concentrations, are resistant to insulin-stimulated glucose uptake and often have accompanying lipid disorders. The pathophysiological significance of these observations lies in the findings that insulin has mitogenic properties and can potentiate vascular smooth muscle growth, thus promoting structural changes in vessels and atherosclerosis. Insulin could also promote high blood pressure via its effect in increasing sodium reabsorption and sympathetic nervous system activity. A variety of therapies is available for treatment of hypertension in patients with metabolic complications. Lifestyle modification is considered to be the initial approach, with weight management the most important component. Although diuretics and beta-blockers have a proven record in reducing morbidity and mortality, they may have adverse effects on glucose, insulin and lipids and should be used with caution in hypertensive subjects with metabolic risks. alpha-adrenergic blockers have favorable effects on lipids and glucose. Calcium antagonists have no adverse effect on glucose or insulin in patients with essential hypertension or diabetic patients with hypertension. ACE inhibitors, on the other hand, have neutral or beneficial effects on glucose, insulin and lipid metabolism, improving insulin sensitivity, insulin secretion, potassium balance and intermediary metabolism. Finally, oral hypoglycemic agents, which improve glucose metabolism and insulin sensitivity, can reduce blood pressure in obese, hypertensive subjects.

Interleukin 4, but not interleukin 5 or eosinophils, is required in a murine model of acute airway hyperreactivity

Reversible airway hyperreactivity underlies the pathophysiology of asthma, yet the precise mediators of the response remain unclear. Human studies have correlated aberrant activation of T helper (Th) 2-like effector systems in the airways with disease. A murine model of airway hyperreactivity in response to acetylcholine was established using mice immunized with ovalbumin and challenged with aerosolized antigen. No airway hyperractivity occurred in severe combined immunodeficient mice. Identically immunized BALB/c mice developed an influx of cells, with a predominance of eosinophils and CD4+ T cells, into the lungs and bronchoalveolar lavage fluid at the time that substantial changes in airway pressure and resistance were quantitated. Challenged animals developed marked increases in Th2 cytokine production, eosinophil influx, and serum immunoglobulin E levels. Neutralization of interleukin (IL) 4 using monoclonal antibodies administered during the period of systemic immunization abrogated airway hyperractivity but had little effect on the influx of eosinophils. Administration of anti-IL-4 only during the period of the aerosol challenge did not affect the subsequent response to acetylcholine. Finally, administration of anti-IL-5 antibodies at levels that suppressed eosinophils to < 1% of recruited cells had no effect on the subsequent airway responses. BALB/c mice had significantly greater airway responses than C57BL/6 mice, consistent with enhanced IL-4 responses to antigen in BALB/c mice. Taken together, these data implicate IL-4 generated during the period of lymphocyte priming with antigen in establishing the cascade of responses required to generate airway hyperractivity to inhaled antigen. No role for IL-5 or eosinophils could be demonstrated.

Secondary aldosteronism

Conditions of secondary aldosteronism are common in clinical medicine, occurring in normotensive and hypertensive settings. In some conditions such as edema disorders, this represents a partially beneficial response to restore volume and Na at the expense of hypokalemia. In RVH and malignant hypertension, the aldosteronism may be beneficial, but most evidence shows a detrimental impact. In both situations, aldosterone does not compensate fully for Na degradation and facilitates K loss. In pregnancy, aldosterone's effects is more successful for volume conservation, and the action on K is almost completely overridden by other K-sparing factors. Chronic renal failure seems to best benefit from hyperaldosteronism, but the response is limited because aldosterone must act on extrarenal targets. In iatrogenic causes of secondary aldosteronism, the effects of aldosterone are mostly detrimental. The overall conclusion supports the hypothesis that aldosterone functions best in physiologic situations, but in pathophysiologic settings it does not perfectly compensate for the basic defect. This implies that in these complex conditions, successful therapy should address the disorder in aldosterone and also the other underlying pathophysiologic mechanisms.

Interferon gamma-independent effects of interleukin 12 administered during acute or established infection due to Leishmania major

Interleukin 12 (IL-12) is a powerful stimulus for the growth of activated T and natural killer cells, their generation of interferon gamma (IFN-gamma), and the differentiation of T helper type 1 (Th1) effector cells from naive precursors in vitro. These activities are consistent with the capacity of exogenous IL-12 to heal otherwise susceptible BALB/c mice infected with the intramacrophage parasite Leishmania major. Using this characterized model of CD4 cell subset differentiation, we examined the immunologic effects of IL-12 administered either at the time of infection, when naive T cells are primed, or after 14 days of infection, by which time CD4+ subset differentiation has occurred. Given with the inoculation of parasites, IL-12 induced IFN-gamma and IL-10 and markedly suppressed IL-4. Effects on IL-10 and IL-4 were comparable in mice with homozygous disruption of the IFN-gamma gene (IFN-gamma 0/0), and suppression of IL-4 was unchanged by administration of neutralizing anti-IL-10 antibody. Induction of IFN-gamma and IL-10 mRNA by IL-12 also occurred in infected SCID mice. Given after day 14 of infection, however, IL-12 not only induced IFN-gamma and IL-10 but also induced IL-4 in normal and IFN-gamma 0/0 mice. These data demonstrate direct effects of IL-12 independent of IFN-gamma, IL-10, and IL-4 and demonstrate that the ineffectiveness of IL-12 administered following infection with L. major correlates with resistance of differentiated Th2 cells to the IL-4-suppressing activity of IL-12.

Differential effects of blockade of CD28-B7 on the development of Th1 or Th2 effector cells in experimental leishmaniasis

Infection of inbred strains of mice with Leishmania major is a well-characterized model for analysis of the development of effector CD4+ subsets of the Th1 and Th2 types in vivo. We co-administered a fusion protein, CTLA4Ig, that blocks the CD28-B7 costimulatory pathway important for optimal T cell activation, to assess the relative role for this pathway during maturation of Th1 and Th2 cells in vivo. Surprisingly, CTLA4Ig administered within the first week of infection completely abrogated progressive disease in susceptible BALB/c mice while having no effect on the protective immune response developed by resistant C57BL/6 mice. The protective effect in BALB/c mice was increasingly lost if administration of CTLA4Ig was delayed longer than 1 wk after infection. As in other protective interventions used in this model, control of infection was associated with down-regulation of IL-4 mRNA transcripts in lymph node cells recovered 5 wk after infection together with abrogation of IgE production and enhanced parasite-specific IgG2a relative to IgG1. Although a single dose of CTLA4Ig was protective, sustained delivery abolished the capacity of BALB/c mice to contain infection, suggesting that costimulation through this pathway is required at later stages of the immune response. Taken together, the data demonstrate that the priming of Th2 cells is more dependent upon the CD28-B7 pathway than the priming of Th1 cells, and suggest that the development of Th subsets in vivo may be influenced by limiting CD28-B7 costimulation.

Differential effects of blockade of CD28-B7 on the development of Th1 or Th2 effector cells in experimental leishmaniasis

Infection of inbred strains of mice with Leishmania major is a well-characterized model for analysis of the development of effector CD4+ subsets of the Th1 and Th2 types in vivo. We co-administered a fusion protein, CTLA4Ig, that blocks the CD28-B7 costimulatory pathway important for optimal T cell activation, to assess the relative role for this pathway during maturation of Th1 and Th2 cells in vivo. Surprisingly, CTLA4Ig administered within the first week of infection completely abrogated progressive disease in susceptible BALB/c mice while having no effect on the protective immune response developed by resistant C57BL/6 mice. The protective effect in BALB/c mice was increasingly lost if administration of CTLA4Ig was delayed longer than 1 wk after infection. As in other protective interventions used in this model, control of infection was associated with down-regulation of IL-4 mRNA transcripts in lymph node cells recovered 5 wk after infection together with abrogation of IgE production and enhanced parasite-specific IgG2a relative to IgG1. Although a single dose of CTLA4Ig was protective, sustained delivery abolished the capacity of BALB/c mice to contain infection, suggesting that costimulation through this pathway is required at later stages of the immune response. Taken together, the data demonstrate that the priming of Th2 cells is more dependent upon the CD28-B7 pathway than the priming of Th1 cells, and suggest that the development of Th subsets in vivo may be influenced by limiting CD28-B7 costimulation.

Constructing polycompetitor cDNAs for quantitative PCR

Analysis of mRNA levels using reverse transcription coupled with the polymerase chain reaction provides a powerful tool for studying cytokine regulation in cellular immunology. We report a novel method for cloning competitor cDNAs that is rapid, efficient and inexpensive. By linking multiple competitor cDNAs in tandem, polycompetitor constructs can be created that allow the use of a single reagent for individual PCR assays. Assays can be performed on minute samples of cell culture or tissue and can be reliably quantitated after routine gel electrophoresis without the use of densitometry or labeled nucleotides. The utility of this technique lies in the ability to produce a relatively inexpensive customized reagent that is simple to use and that allows for sensitive determinations of gene expression in a rapid and convenient manner. This method should allow investigators in many areas of biology to easily quantitate a broad range of important regulatory molecules.

Increased Na/H antiport activity and abundance in uremic red blood cells

Alterations in red blood cell sodium (Na) transport have been described in chronic renal failure. This study examines the possible impact of uremia on two ouabain-insensitive pathways, the Na/H antiporter and the Cl-/NaCO3- anion exchanger. The Vmax of Na/H antiporter measured as Na influx driven by outward H gradient in acid loaded red blood cells was significantly higher in uremic red blood cells versus controls (60.5 +/- 16.5 vs. 24.5 +/- 5.4 mmol/liter cells/hr, P < 0.025). This increase in activity was associated with an increased abundance of the Na/H antiporter as determined by immunologic analysis using an affinity purified polyclonal antibody to the human NHE-1 isoform of the antiporter. By contrast, the activity of the anion exchanger measured as the DIDS-sensitive lithium (Li) influx was similar in uremic versus control red blood cells (2.10 +/- 0.18 vs. 2.14 +/- 0.20 mmol/liter cells/hr). These experiments, when considered in conjunction with prior studies showing normal Na/Li countertransport in uremia indicate that there is a selective increase in the number of functional Na/H antiporters in uremic red blood cells and that Na/Li countertransport measurements may not be a valid marker for Na/H antiporter activity in red blood cells in patients requiring dialysis for end-stage renal failure.

Long-term effects of the angiotensin converting enzyme inhibitor captopril on metabolic control in non-insulin-dependent diabetes mellitus

The role of angiotensin converting enzyme (ACE) inhibitors in improving insulin-mediated glucose uptake has been described. However, their effects on long-term glucose control in diabetes mellitus are less well established. This study examines the effect of 4 months of captopril treatment on blood pressure (BP) and glucose control in 130 subjects with non-insulin-dependent diabetes mellitus (NIDDM) and hypertension. Therapy for glycemic control was adjusted during a 3 month period prior to entry into active BP treatment and was not changed during 4 months of captopril administration. Fasting blood glucose and sitting BP were measured before and at 1, 2, 3, and 4 months of captopril monotherapy. Hemoglobin (Hb) A1c, serum electrolytes, creatinine, total cholesterol, and triglycerides were measured before and at 4 months. There were significant reductions in fasting blood glucose from baseline at 1 month (P < .01) and further stepwise decreases in values at 2, 3, and 4 months. Differences in glucose from month to month were highly significant. HbA1c was stable over a 3-month pretrial period, then decreased (P < .001) from baseline at 4 months of active treatment. Mean serum potassium increased from 4.4 to 4.7 (P < .001) at month 4 and there was an inverse correlation (r = -0.2, P < .025) between changes in potassium and HbA1c. Total serum cholesterol fell (P < .01) at month 4 of treatment. Serum creatinine and blood urea were unchanged, but of 18 patients with mild proteinuria pretrial, 12 of 18 were negative for protein at 4 months.(ABSTRACT TRUNCATED AT 250 WORDS)