Effect of L-Tryptophan Supplementation on Eosinophils and Eotaxin in Guinea Pigs

Eosinophilie Myalgia Syndrome is a hypereosinophilic disorder that appears to result from the ingestion of the dietary supplement L-tryptophan by susceptible individuals. It is unclear if this disease results from tryptophan, contaminants found in tryptophan, individual predisposition (such as immune status and allergies), or some combination of effects. To evaluate effects of L-tryptophan on eosinophil migration, guinea pigs were compared with or without supplemental tryptophan (0. g/kg/day), with or without immune sensitization, and with or without immune challenge. Eosinophil counts were obtained from bone marrow, blood, lung, and bronchial alveolar lavage fluid (BAL). Lung cells were obtained to measure eotaxin concentrations in supernates and lysates with or without antigen and calcium ionophore challenge using direct ELISA. Skin biopsies were taken from both non-injected and antigen injection sites. The tryptophan supplemented, antigen-sensitized/antigen-challenged guinea pigs showed a significant decrease in blood eosinophils, compared to control (cellulose) supplemented antigen-sensitized/antigen-challenged guinea pigs [(0.086 ± 0.023) × 106 vs (0.147 ± 0.021) × 106 eoslnophils/ml recovered, respectively] with a significant increase in BAL eosinophils [(0.052 ± 0.008) × 106 vs (0.033 ± 0.005) × 10s eosinophils/ml recovered, respectively]. Unchallenged lung cell lysates from tryptophan-supplemented guinea pigs contained significantly less eotaxin compared to cellulose-supplemented guinea pigs regardless of whether they were sensitized (0.006 ± 0.002 vs 0.027 ± 0.008 ng/106 cells, respectively). No differences were observed in skin biopsies between cellulose and tryptophan groups. These results suggest that L-tryptophan-supplemented guinea pigs have altered eotaxin regulation, a potential mechanism by which human overconsumption of tryptophan dietary supplements could lead to hypereosinophilic disorders in susceptible individuals.

Mortality and loss to follow-up among tuberculosis and HIV co-infected patients in rural southwestern Uganda

BACKGROUND

We describe the presentation and outcome of care among patients with tuberculosis (TB) and human immunodeficiency virus (HIV) co-infection from a prospective observational cohort in Uganda.

METHODS

We analysed basic demographics, CD4+ counts, time of initiating antiretroviral therapy (ART), clinical and haematological parameters and outcome of care of 386 patients enrolled between February 2007 and March 2010.

RESULTS

At presentation, 56.7% of the patients were sputum-positive, 89.9% had new TB infection, 62.7% had wasting, 78.7% were anaemic, 72.1% had a CD4+ count of <200 cells/mm(3), 20.2% had pneumonia, 50.3% had oral thrush and 1.3% had Kaposi's sarcoma. Patients developing TB within 3 months of starting ART were less likely to have wasting, to be anaemic or to have a CD4+ count of <100 cells/mm(3). The cure, default and death rates were respectively 54.3%, 24% and 16%. At 8 months, 53 (13.7%) were confirmed dead, 119 (30.8%) were lost to follow-up, 28 (7.3%) were transferred out and 1 (0.3%) had treatment failure. Mortality and loss to follow-up were associated with failure to start ART and having a CD4+ count of <200 cells/mm(3).

CONCLUSION

In Uganda, TB-HIV patients present with severe immune suppression and are at increased risk of death and loss to follow-up, particularly those not on ART. There is need for early identification and improved follow-up of TB-HIV co-infected patients.

Vitamin D and calcium levels in Ugandan adults with human immunodeficiency virus and tuberculosis

BACKGROUND

Vitamin D increases cathelicidin production, and might alter mortality due to tuberculosis (TB) in human immunodeficiency virus (HIV) coinfection. However, due to abundant sun exposure, vita min D levels might be excellent among Ugandans with HIV and TB.

METHODS

We measured 25(OH)D and calcium levels in 50 HIV-negative, 50 HIV-infected and 50 TB-HIV coinfected Ugandan adults.

RESULTS

Mean ± standard deviation 25(OH)D levels were 26 ± 7 ng/ml in HIV-negative, 28 ± 11 ng/ml in HIV-infected and 24 ± 11 ng/ml in TB-HIV co-infected adults (P > 0.05 all comparisons). Vitamin D deficiency (< 12 ng/ml) was present in 10% of the HIV-infected subjects, 12% of the TB-HIV co-infected and none of the healthy controls (P = 0.03 for healthy vs. TB, P > 0.05 for other comparisons); 20% of the healthy controls, 22% of the HIV-positive and 38% of the TB-HIV co-infected subjects (P = 0.047 for healthy vs. TB, P > 0.05 for other comparisons) had suboptimal vitamin D levels (< 20 ng/ml). No participant had hypercalcemia. Serum 25(OH)D levels correlated positively with body mass index (r = 0.22, P = 0.03) and serum calcium levels (r = 0.18, P = 0.03).

CONCLUSIONS

Ugandan HIV-infected adults with and without TB commonly had suboptimal vitamin D levels. Clinical trials are needed to evaluate the effect of vitamin D on health outcomes in HIV-infected patients with low vitamin D levels.

Low-activity (2.0 GBq; 54 mCi) radioiodine post-surgical remnant ablation in thyroid cancer: comparison between hormone withdrawal and use of rhTSH in low-risk patients

OBJECTIVE

(a) To compare the efficacy of low-activity (2 GBq; 54 mCi) (131)I ablation using l-thyroxine withdrawal or rhTSH stimulation, and (b) to assess the influence of thyroid remnants volume on the ablation rate.

DESIGN

Patients underwent neck ultrasound, (131)I neck scintigraphy and radioiodine uptake. Post-therapy whole body scan (WBS) was acquired after 4-6 days. Ablation was assessed after 6-12 months by WBS, Tg and TgAb following l-thyroxine withdrawal.

METHODS

Group A: preparation by L-T(4) withdrawal (37 days); 21 patients received (131)I (2.02+/-0.22 GBq; 54.6+/-5.9 mCi) and on the day of treatment, TSH, Tg, TgAb were measured; Group B: stimulation by rhTSH; 21 patients received (131)I (1.97+/-0.18 GBq; 53.2+/-4.9 mCi) 24 h after the second injection of rhTSH (0.9 mg) and TSH, Tg and TgAb were measured after 2 days.

RESULTS

At follow-up, 90.0% of patients from group A and 85.0% of patients from group B had Tg levels <1 ng/ml; no uptake was observed in 95.2% and in 90.5% of patients from group A or B respectively, with no statistical differences for both ablation criteria. Before (131)I treatment, small thyroid remnants (<1 ml) were detected by US in <25% of all patients.

CONCLUSIONS

The use of rhTSH for the preparation of low-risk patients to ablation therapy with low activities of (131)I (2 GBq; 54 mCi) is safe and effective and avoids hypothyroidism. The presence of thyroid remnants smaller than 1 ml at US evaluation had no effect on the ablation rate.

Trend in thyroid carcinoma size, age at diagnosis, and histology in a retrospective study of 500 cases diagnosed over 20 years

Recently, the Italian Network of Cancer Registries analyzed 5101 cases of thyroid carcinoma showing a reduction of mortality rate of 4%/year. This prompts us to evaluate the temporal trend in tumor size, age at diagnosis, and histology in a retrospective analysis of 500 thyroid cancers diagnosed over 20 years. Thyroid cancers were divided in two groups. The first included 193 cases diagnosed from 1985 to 1994, and the second 307 from 1995 to 2004. The size of all tumors was significantly reduced from 30 +/- 1.4mm in the first group to 15 +/- 0.8mm in the second group. In particular, papillary thyroid carcinoma (PTC) size decreased from 28 +/- 1.2mm to 14 +/- 0.8mm and follicular carcinoma from 40 +/- 6.3mm to 17 +/- 4.5 mm. Age at diagnosis of all carcinomas increased significantly from 40 +/- 1.3 years in the first group to 48 +/- 0.9 years in the second group. Analysis of the histological types revealed a significant increase of PTC rate in the second decade from 82% to 92% and a concomitant reduction of anaplastic thyroid carcinoma (ATC) from 3.7% to 1.0%. Moreover, a significant increase of micro-PTC rate, from 7.3% to 36.4%, was observed. In conclusion, it may be speculated that the above mentioned decreased mortality rate for thyroid carcinoma could be related to the significant reduction with time of cancer size, to the progressive increase of PTC rate and to the reduction of ATC rate. These data, if confirmed in other series, underscore the importance of evaluating thyroid nodules smaller than 10mm and corroborate recent findings suggesting that age be reconsidered as an independent prognostic factor for differentiated thyroid cancers.

Differential expression of the components of the plasminogen activating system in human thyroid tumour derived cell lines and papillary carcinomas

We characterised the expression of the plasminogen activators (uPA and tPA), the uPA receptor (uPAR) and the PAs inhibitors (PAI-1 and PAI-2) in human thyroid cell lines derived from normal thyroid, follicular adenoma, follicular, papillary and anaplastic carcinomas. Urokinase PA activity was detected in the supernatant of normal thyrocytes and augmented in those of all tumour cells. Quantitative RT-PCR analysis showed that uPA, uPAR and PAI-1 mRNAs increased in all carcinoma cells. Similar results were found in 13 papillary thyroid carcinoma (PTC) tissues which were mirrored in Western blot experiments. A correlation was found between tumour size and uPA mRNA increase, and higher levels of uPA and uPAR mRNAs were found in metastatic PTC. In conclusion, thyroid carcinoma cell lines and PTC overexpress uPA, uPAR and PAI-1 and the correlation of uPA and its cognate receptor with tumour size and metastasis may suggest their potential prognostic relevance in thyroid cancer.

Expression of matrix metalloproteinases and their specific inhibitors in normal and different human thyroid tumor cell lines

In the present study we investigated, by means of zymography and reverse transcription-polymerase chain reaction (RT-PCR), the expression of different matrix metalloproteinases (MMPs) and of the specific tissue inhibitor of metalloproteinases [TIMPs] in human cell lines derived from normal thyrocytes (HTU5), follicular adenoma (HTU42), and follicular (FTC-133), papillary (B-CPAP), and anaplastic (CAL-62, 8305C) thyroid carcinomas. We demonstrated that normal thyrocytes constitutively express MMP-1, MMP-2, MMP-10, MMP-14, and TIMP-1, TIMP-2, TIMP-3, and TIMP-4, and this pattern of expression is profoundly modified in all thyroid tumor-derived cell lines. Analysis of the gelatinolytic activity in the different cell supernatants showed that the expressions of MMP-2 and MMP-9 are, respectively, increased or induced in all the neoplastic cell lines, except in CAL-62. Caseinolytic activity was found only in the supernatants of the 8305C and B-CPAP cells. Using RTPCR analysis we detected an increased expression of MMP-1 in cell lines derived from papillary and from one (8305C) of the two anaplastic carcinomas. MMP-13 mRNA was expressed only in the 8305C, FTC-133, and BCPAP cells. Among stromelysins, MMP-3 mRNA could not be detected in any cell line, while MMP-10 mRNA was expressed in all of them, although at variable levels. MMP-11 mRNA was absent in normal and follicular adenoma derived thyrocytes and induced in all carcinoma cell types. The expression of MMP-14 (MT1-MMP) mRNA was found significantly increased in all thyroid tumor cell lines with respect to HTU5 and HTU42 cells. The expression of TIMP-1 and TIMP-2 mRNAs was maintained in all cell lines tested, while that of TIMP-3 was lost in both anaplastic carcinoma cell lines and that of TIMP-4 was absent in the CAL-62. In conclusion, our data demonstrated a differential expression of MMPs and TIMPs in different thyroid tumor cell types with respect to normal thyrocytes. In particular, the induction of MMP-11 in all thyroid-derived carcinoma cell lines studied and of MMP-13 in all but one may represent, if confirmed in other thyroid tumor-derived cell lines and in thyroid tumor tissues, a new marker of thyrocyte transformation.

Iodine supplementation restores fertility of sheep exposed to iodine deficiency

The aims of the study were to monitor sheep iodine intake in different sheep breeding farms in Abruzzo and to evaluate the effects of iodine supplementation on ovine fertility. The urinary iodine concentrations (UIC) in animals of 8 out of the 11 breeding farms analyzed were borderline (UIC 100-150 microg/l) or very low (UIC < or = 50 microg/l). Only animals bred in 3 farms showed an adequate iodine intake with a mean UIC > or = 300 microg/l. Animals with very low iodine intake had lower T4 and T3 (p < 0.01) serum levels, compared to those with adequate iodine intake. To investigate the effects of iodine supplementation on ovine fertility, 32 ewes and 20 rams, characterized by low UIC, were randomly divided into 2 groups. One group (16 ewes and 10 rams) received a sc injection of 1 ml of Lipiodol, containing 480 mg of iodine, while the remaining animals were employed as control. This treatment was able to maintain UIC above 300 microg/l for 3 months and to increase T4 and T3 serum levels (p < 0.01). After 9 months, the fertility of control and treated animals was assessed by monitoring the rate of successful matings by ultrasonography. The results showed that 100% of treated ewes mated with treated rams were pregnant vs 37% of the control ewes mated with control rams (p = 0.007). The iodine content was 4-fold higher in milk from treated ewes (2393 +/- 453 microg/l), compared to controls (675 +/- 154 microg/l). The results demonstrated that iodine supplementation restores fertility of sheep living in iodine deficient areas and may represent a means to achieve a silent iodine prophylaxis of local populations.

Protease inhibitor drug levels in the management of human immunodeficiency virus-1 antiretroviral therapy

In order to evaluate the relationship between protease inhibitor (PI) plasma concentrations and viral suppression in individuals receiving highly active antiretroviral therapy (HAART), plasma concentrations and area under the time concentration curve (AUC(0.5-4)) for 35 HIV-infected adults receiving their initial (or first salvage) nelfinavir- (NFV) or indinavir (IDV)-based HAART were studied. Two groups were evaluated: those who had achieved HIV-RNA suppression (HIV-RNA <500 copies/mL, group 1, n=21) and those who had achieved incomplete HIV-RNA suppression (HIV-RNA>500 copies/mL, group 2, n=14) at the time of study entry. NFV one-hour pre-dose concentrations were significantly higher in group 1 compared to group 2 (P=0.023). The NFV AUC(0.5-4) for group 1 approached significance (P=0.068). No significant differences in IDV concentrations or AUC(0.5-4) were found between group 1 and group 2. It is feasible to use PI drug level monitoring in the outpatient setting.

Mechanisms of antihistamines and mast cell stabilizers in ocular allergic inflammation

Mast cells play a central role in allergic reactions and inflammation. Successful anti-allergic therapies have typically targeted mast cell mediators, particularly histamine. Antihistaminic compounds interact with the various histamine receptors found on many cells, whereas other compounds such as disodium cromoglycate, are referred to as mast cell stabilizers, as they inhibit degranulation. Some of the most successful compounds developed recently are dual-action, in that they have both anti-histaminic and mast cell stabilizing activities. Recent trends in pharmaceutical intervention, however, have been focused on the secondary effects of mast cell mediators on epithelial cell adhesion molecule expression and mediator release in the process of allergic inflammation. Since, the ocular mucosa is highly exposed to environmental allergens it is commonly involved in allergic reactions and, as such, has been a useful and accessible model in which to test new therapies in vivo. These ocular allergen provocation studies permit analysis of ocular surface cells and evaluation of tear film mediators. Furthermore, techniques to purify conjunctival mast cells have facilitated the study of the effects of mast cell stabilizing compounds on other mast cell mediators, such as cytokines, and the direct effects of mast cell mediators on epithelial cells in vitro. This review will discuss current understanding of how anti-histamines and mast cell stabilizers work, particularly in the context of molecular mechanisms of ocular allergic inflammation.

Olopatadine inhibits anti-immunoglobulin E-stimulated conjunctival mast cell upregulation of ICAM-1 expression on conjunctival epithelial cells

BACKGROUND

Olopatadine is a clinically effective dual-action (antihistamine/mast cell stabilizer) ophthalmic antiallergic agent. We have previously demonstrated that olopatadine inhibits tumor necrosis factor alpha (TNF-alpha) release from purified human conjunctival mast cells and that supernates from stimulated mast cells upregulate intercellular adhesion molecule 1 (ICAM-1) expression on epithelial cells via TNF-alpha.

OBJECTIVE

To investigate the effect of olopatadine on the TNF-alpha-mediated mast cell upregulation of ICAM-1 expression on conjunctival epithelial cells.

METHODS

Human conjunctival mast cells and epithelial cells were purified (>95%) from cadaveric tissue. Conjunctival mast cells were preincubated with three doses (30, 300, or 3,000 microM) of olopatadine or buffer alone for 30 minutes followed by 90-minute challenge with anti-immunoglobulin E (10 microg/mL). The resulting supernates were incubated with conjunctival epithelial cell monolayers for 24 hours along with the following treatments: rTNF-alpha, mast cell supernate + anti-TNF-alpha, recombinant (r)TNF-alpha + anti-TNF-alpha, the three doses of olopatadine, olopatadine supernates, olopatadine supernates + rTNF-alpha. ICAM-1 expression was measured using flow cytometry.

RESULTS

Anti-IgE-stimulated human conjunctival mast cell supernates upregulated human conjunctival epithelial cell ICAM-1 expression to the same extent as rTNF-alpha. ICAM-1 upregulation could be completely blocked with anti-TNF-alpha. Preincubation of conjunctival mast cells with olopatadine significantly blocked the ability of supernates to upregulate ICAM-1 on conjunctival epithelial cells. ICAM-1 expression could be restored by adding rTNF-alpha to the olopatadine-preincubated mast cell supernates.

CONCLUSIONS

Olopatadine is able to significantly decrease the anti-immunoglobulin E mast cell supernate-mediated upregulation of ICAM-1 on human conjunctival epithelial cells in vitro. This seems to be mediated through an effect on a TNF-alpha-specific mechanism.

Simultaneous measurement of six cytokines in a single sample of human tears using microparticle-based flow cytometry: allergics vs. non-allergics

Tears play an essential role in maintaining corneal and conjunctival integrity by providing a tightly regulated, optimal extracellular environment critical to its numerous functions, which include anti-microbial defense, wound healing and inflammatory responses such as allergies. Elevated levels of inflammatory cytokines have been reported in tears from various ocular disease states. Characterization of tear cytokines has been limited by the small volume (microliter amounts) attainable. This limitation was addressed with the newly developed Becton Dickinson Cytometric Bead Array (CBA), which combines the principles of the "sandwich" immunoassay with the capability of flow cytometry for simultaneous measurement of the characteristics of multiple particles. This technique allows determination of six human cytokine (IFNgamma, TNFalpha, IL-2, IL-4, IL-5, IL-10) concentrations simultaneously in a single tear sample. Tears were collected from the inferior fornix of non-allergic (n=7) and allergic (n=9) donors. Each tear sample or cytokine standard was incubated with a mixture of capture Ab-bead reagent and detector Ab-phycoerythrin (PE) reagent, and analyzed using flow cytometry. All six cytokines were detectable in both non-allergic and allergic tears. Tears from allergic donors contained significantly less IL-10 (p=0.035), and had significant increases in the ratios of TNFalpha/IFNgamma, IL-5/IFNgamma and IL-5/IL-10 (p=0.0008, 0.0124 and 0.011, respectively). The small volume required (5-10 microl/test) by the Cytometric Bead Array allows measurement of all six cytokines from a single collection of tears. This decreases collection time, minimizing the confounding effect of stimulation on cytokine concentration in tears, as well as allowing calculation of cytokine ratios.

Conjunctival mast cells in ocular allergic disease

Allergic eye disease is a common clinical problem adversely affecting the quality of life for millions of sufferers. This ocular process is associated with IgE-mediated conjunctival inflammation leading to signs of immediate hypersensitivity including redness, itching, and tearing. Pathologic studies have shown that the conjunctiva contains mast cells that when sensitized with IgE antibody and exposed to environmental allergens can release mediators of allergic inflammation. The type, release kinetics, and concentration of these mediators in the conjunctiva have not been completely characterized. The ability to isolate and purify mast cells and epithelial cells from human conjunctival tissue has permitted the study of mediator release and cell-to-cell signaling in this tissue. Our laboratory has developed in vitro and in vivo models to better understand how inflammatory cells are recruited to and infiltrate conjunctival tissues. These models demonstrate that mast cell activation may supply sufficient cytokine signaling to initiate and direct the well-orchestrated trafficking of eosinophils to the ocular surface, facilitate their adhesion, and cause release of potent mediators of ocular inflammation.

Immunologic and virologic effects of subcutaneous interleukin 2 in combination with antiretroviral therapy: A randomized controlled trial

CONTEXT

While interleukin 2 (IL-2) is capable of inducing a marked expansion of the CD4 T-lymphocyte pool, limited data exist on whether IL-2 treatment can add significantly to the immunologic and virologic effects of potent antiretroviral therapy (ART).

OBJECTIVE

To determine the rate and magnitude of CD4 cell recovery and viral suppression when using a combination therapy of IL-2 and ART compared with ART alone.

DESIGN AND SETTING

Randomized, controlled multicenter trial conducted from April 1996 through April 1998 at 8 clinical sites in the United States.

PATIENTS

Eighty-two adult outpatients who were infected with human immunodeficiency virus (HIV) and had baseline CD4 cell counts of 200 x 10(6)/L to 500 x 10(6)/L and baseline RNA levels of fewer than 10,000 copies/mL were randomized; 78 completed the study.

INTERVENTIONS

Thirty-nine patients were randomly assigned to receive a combination therapy of subcutaneous IL-2 (administered in 5-day courses every 8 weeks at a starting dosage of 7.5 mIU twice per day) and ART; 43 were to receive ART therapy alone.

MAIN OUTCOME MEASURES

Interleukin 2 safety and differential effects on CD4 cell counts, CD4 cell percentages, and plasma HIV RNA levels.

RESULTS

The mean (SD) percentage increase in CD4 cell counts at 1 year for patients who received IL-2 was 112% (113%) compared with 18% (35%) in recipients of ART alone (P<.001). Both groups had mean (SD) increases in CD4 cell percentage: from 20.4% (6.3%) to 32.3% (12.4%) for the combination therapy group compared with 20.4% (5.1%) to 23.0% (7.2%) for recipients of ART alone (P<.001). Using a sensitive viral RNA assay, mean viral load changes were -0.28 and 0.09 log(10) copies for IL-2 recipients and control patients, respectively (P=.03). Twenty (67%) of 30 evaluable patients receiving IL-2 achieved final viral loads of fewer than 50 copies/mL compared with 13 (36%) of 36 control patients (P=.02). Toxic effects were common among patients who received IL-2 and were managed with antipyretics, hydration, rest, and dosage reduction as needed.

CONCLUSIONS

Intermittent therapy with IL-2 and ART produced a substantially greater increase in CD4 cells and was associated with a larger decrease in viral load than ART alone. Clinical end-point trials will be necessary to determine whether the enhanced viral suppression and CD4 cell increases associated with IL-2 therapy will translate into improved clinical outcomes. JAMA. 2000;284:183-189

Antihistamines and epithelial cells

Antihistamines have long been utilized in the symptomatic management (antihistaminic effects) of allergic rhinitis and conjunctivitis. Investigation into the nonsedating second-generation antihistamines suggests that they also possess antiinflammatory activity, and may be useful in the management of inflammation associated with allergic airway disease. In vitro studies have shown that these antihistamines decrease the migration and activation of eosinophils and diminish the release of pro-inflammatory mediators from mast cells and basophils after induction by immunological and nonimmunological stimuli. In vivo studies have also demonstrated that these antihistamines decrease inflammatory cell infiltration in allergic airway disease, and mediator release from mast cells and basophils. Epithelial cells, due to their spatial arrangement and predominance in the airways, play a pivotal role in the etiology of airway disease. There is evidence that antihistamines may modulate airway inflammation by influencing the activity of these airway epithelial cells. Studies have shown that expression of adhesion molecules on epithelial cells is decreased by second-generation antihistamines. Collectively, these studies suggest that second-generation H1-histamine receptor antagonists have potential use either as safe antiinflammatory alternatives to corticosteroids or as rescue medication in combination with corticosteroids for the management of severe airway disease.

Olopatadine inhibits TNFalpha release from human conjunctival mast cells

BACKGROUND

Tumor necrosis factor-alpha (TNFalpha) release likely plays a crucial role in allergic ocular inflammation via increasing ICAM-1 on epithelial cells and triggering other proinflammatory events. The immediate and prolonged release of TNFalpha from human conjunctival mast cells in response to allergen challenge is potentially an important target for therapeutic intervention, yet the effect of ocular anti-allergic agents on this process has not been examined. Olopatadine (Patanol) is a clinically effective dual-action ophthalmic anti-allergic agent that has been shown to inhibit mast cell histamine, tryptase, and PGD2 release in vitro and promote decreased H1 receptor binding activity in vitro and functional H1 receptor antagonism in vivo.

OBJECTIVE

To investigate the effect of olopatadine on TNFalpha release from anti-IgE antibody challenged purified human conjunctival mast cells.

METHODS

Human conjunctival mast cells were purified (>95%) from cadaveric tissues using a procedure combining enzymatic digestion and Percoll gradient centrifugation. These cells were incubated with olopatadine for 30 minutes then challenged with anti-IgE antibody for 90 minutes. Supernatants were analyzed for TNFalpha.

RESULTS

Purified human conjunctival mast cells responded to anti-IgE antibody challenge with TNFalpha release in a concentration dependent manner (optimum concentration was 10 microg/mL). Olopatadine pre-incubation resulted in a dose-dependent decrease in anti-IgE antibody mediated TNFalpha release (IC50 = 13.1 microM). At a concentration of 3 mM olopatadine reduced TNFalpha release to the level of unchallenged controls.

CONCLUSION

Olopatadine inhibited anti-IgE antibody-mediated release of TNFalpha from human conjunctival mast cells. This effect could contribute to the long duration of anti-allergic activity reported for the drug.

Therapeutic drug monitoring of antiretroviral agents

HIV+ patients fail antiretroviral therapy due to inadequate drug concentrations reaching the site of viral replication and/or the development of viral resistance to the antiretroviral agents. Adequate drug concentrations may not be reaching the virus due to poor compliance, poor absorption, or other pharmacokinetic factors such as metabolism, elimination, and drug interactions. The most important and most common pharmacokinetic drug interactions involve inhibition of metabolism, induction of metabolism, altered drug absorption, inhibition of renal excretion, and displacement from plasma protein binding sites. If a patient is failing antiretroviral therapy, TDM of antiretroviral agents could help in determining both adequacy of drug concentrations and patients' adherence. Ongoing studies will determine whether total drug concentration or free drug concentration of the protease inhibitors is the best predictor of response. Trough concentrations could prove to be the most important predictor of response, but additional studies are needed to compare trough, peak, and AUC concentrations with response to treatment. Finally, if some patients fail therapy due to inadequate drug concentrations, then increasing the dose could benefit patients' outcome and increase longevity. Clinical trials are needed that compare patients who receive a fixed-dosage regimen with patients who have adjusted dose regimens. Such a study is the best way to determine the true value of TDM of the antiretrovirals.

Cytokines, chemokines, RANTES, and eotaxin

Over the past several years, a number of cytokines with chemoattractive properties (chemokines) have been identified. These low molecular weight molecules have been shown to be important leukocyte chemical attractants to sites of inflammation and infection. Chemokines act on leukocytes through selective receptors and are now known to function also in leukocyte maturation, trafficking, and homing of these cells. RANTES and eotaxin (among other chemokines) are important chemoattractants for eosinophils. Since eosinophils seem to play a critical role in the production of allergic inflammation, an understanding of the mechanism of action of these chemokines may lead to new therapies for asthma and other allergic processes.

Human conjunctival mast cells: expression of Fc epsilonRI, c-kit, ICAM-1, and IgE

OBJECTIVE

To characterize the expression and regulation of conjunctival mast cell surface receptors important in allergic inflammation.

METHODS

Mast cells were isolated from human conjunctival tissues of cadavers. Mast cell surface markers were identified using flow cytometry with antibodies to IgE, Fc epsilonRI, c-kit, and intercellular adhesion molecule-1 (ICAM-1). We evaluated the effect of 24-hour tumor necrosis factor alpha (TNF-alpha) or interleukin 4 (IL-4) incubation on the expression of mast cell c-kit, ICAM-1, and surface-bound IgE.

RESULTS

Staining of mast cells (c-kit and/or tryptase positive) yielded positive results for all of the variables measured. The intensity of mast cell c-kit staining increased with TNF-alpha incubation, but decreased below that of unstimulated mast cells when incubated with IL-4. Anti-ICAM-1 and anti-IgE staining were increased over that of unstimulated cells when incubated with TNF-alpha or IL-4.

CONCLUSIONS

In this model, TNF-alpha up-regulates mast cell surface receptors and cell-bound IgE. Interleukin 4 up-regulates mast cell ICAM-1 and cell-bound IgE, but down-regulates c-kit.

CLINICAL RELEVANCE

Conjunctival mast cells play a critical role in the pathogenesis of atopic ocular disease. Characterization of the expression and regulation of mast cell surface receptors is important to the development of potential novel treatments for ocular inflammation.

The role of IgG1 and IgG2 in trimellitic anhydride-induced allergic response in the guinea pig lung

Trimellitic anhydride (TMA) is a small molecular weight chemical used in the paint and plastics industry that can cause asthma-like symptoms in humans. Guinea pigs sensitized intradermally with TMA will respond to antigen challenge with asthma-like symptoms, including an immediate bronchoconstriction and a delayed cellular infiltration into the lung, particularly eosinophil infiltration. Sensitized guinea pigs produce TMA-specific IgG1, which is thought to be important in asthmatic reactions in this animal model; however, they also produce TMA-specific IgG2 antibody. The purpose of the present study was to determine the role of IgG1 and IgG2 in the TMA-induced immediate bronchoconstriction and delayed cellular infiltration in the guinea pig. Guinea pigs were passively sensitized by intratracheal instillation of TMA-specific IgG2, an antibody preparation enriched with TMA-specific IgG1, or a combination of the two. The allergic response was induced by intratracheal instillation of TMA conjugated to guinea pig serum albumin (TMA-GPSA). A significantly greater bronchoconstrictor response was observed in animals sensitized with a combination of the IgG2 and IgG1 preparation compared to those sensitized with IgG2 or the IgG1 preparation alone. Cellular infiltration was quantified 24 h after antigen challenge by differential cell counts of bronchoalveolar lavage (BAL) cells as well as by using eosinophil peroxidase (EPO) and myeloperoxidase (MPO) activity as a measure of the numbers of eosinophils and neutrophils, respectively. In the BAL, passively sensitizing with IgG2 alone resulted in an increase in both TMA-induced MPO and EPO activity. In contrast, in the lung, passively sensitizing with a partially purified preparation of TMA-specific IgG1 alone resulted in a significant increase in TMA-induced EPO activity. Passively sensitizing with IgG2 in conjunction with the IgG1 preparation resulted in an enhanced cellular infiltration and lung injury over that seen with either antibody preparation alone. These data demonstrate an augmentation of IgG1-mediated responses by the addition of IgG2 and suggest a significant role for both subclasses of IgG antibodies in this guinea pig model of TMA-induced occupational asthma.

Sulfa hypersensitivity in patients with HIV infection: onset, treatment, critical review of the literature

Trimethoprim/Sulfamethoxazole is the most effective medication used in both the treatment and prevention of Pneumocystis carinii pneumonia (PCP) in patients with HIV/AIDS. Its use, however, is accompanied by a high incidence of adverse reactions, especially fever, myalgia and rash (sulfa hypersensitivity). In a group of our patients, we have examined the clinical parameters at the time of onset of sulfa hypersensitivity, and the success of a desensitization protocol for this adverse event. We also have performed a comprehensive review of the literature on sulfa hypersensitivity and have compared our results to those previously reported in the literature. Our findings indicate that the sulfa hypersensitivity reaction is more likely to develop in patients with advanced disease and that desensitization can restore tolerability to the drug in approximately two thirds of those who attempt it.

Regulation by thyroid hormone of the expression of basement membrane components in rat prepubertal Sertoli cells

The present study reports the modulation of basement membrane (BM) components, laminin, entactin, and type IV collagen, expression in prepubertal rat Sertoli cell by the thyroid hormone T3. Immunocytochemical studies of permeabilized Sertoli cells in culture showed that T3 treatment (10[-7] M for 24 h) increased the number of cells staining positive for laminin and/or entactin (from 58 +/- 5.3% to 86.4 +/- 6.5%, P < 0.01). In contrast, a strong inhibition of type IV collagen immunopositivity was observed. Western blot analysis of Sertoli cell-conditioned media indicated that T3 treatment significantly (P < 0.01) increased the level of secreted entactin by 60-65% without affecting the levels of laminin A and B1/B2 chains. Moreover, thyroid hormone treatment of Sertoli cells significantly reduced type IV collagen secretion by 62% (P < 0.05). Slot blot analysis of poly-A RNA demonstrated a significant (P < 0.01) increase in the level of entactin messenger RNA (mRNA) by 140% (P < 0.01) and a 50% reduction of type IV collagen alpha1 chain mRNA after thyroid hormone treatment. No effect of the hormone was observed on the accumulation of the laminin B1 and B2 chain mRNAs in Sertoli cell cultures. These effects cannot be ascribed to changes in the degradation of BM components, because no effect of thyroid hormone was observed on plasminogen activators or metalloproteinase secretion by Sertoli cells. These observations indicate the Sertoli cell as a source of entactin within the testis, demonstrate the ability of T3 to differentially regulate the expression of BM components, and can be regarded as a part of the integrated mechanism by which thyroid hormone affects testicular development and differentiation.

Isolation of human conjunctival mast cells and epithelial cells: tumor necrosis factor-alpha from mast cells affects intercellular adhesion molecule 1 expression on epithelial cells

PURPOSE

To isolate and purify mast cells and epithelial cells from human cadaveric donor conjunctival tissue and to characterize interactions between these cell types in vitro.

METHODS

Monodispersed cell suspensions obtained by enzymatic digestion of conjunctival tissue were applied to a single-density Percoll gradient. Epithelial cells obtained from the top layer of the gradient were cultured to confluence. Mast cells obtained from the pellet were equilibrated in culture medium and further purified using a two-step Percoll gradient. Using reverse transcription-polymerase chain reaction (RT-PCR), RNA from the purified mast cell preparation was probed for tumor necrosis factor-alpha (TNF alpha) message. Fluorescence activated cell sorting (FACS) analysis of intracellular immunostained mast cells was used to detect the TNF alpha protein. An examination for intercellular adhesion molecule 1 (ICAM-1) on epithelial cells was performed after 24-hour incubations with either recombinant TNF alpha supernatants from calcium ionophore A23187 (CaI)-stimulated mast cells or appropriate controls using FACS analysis.

RESULTS

Highly purified human conjunctival mast cells and epithelial cells (each > 95%) were obtained from human cadaveric donor tissue. RT-PCR analysis of purified mast cell RNA revealed the expression of TNF alpha mRNA. An evaluation of mast cells for intracellular protein demonstrated positive staining for tryptase and TNF alpha. ICAM-1 was found on purified epithelial cells, and incubation of epithelial cell monolayers with supernatants from Cal-stimulated mast cells resulted in upregulation of this receptor. This upregulation was blocked by incubation with TNF alpha-neutralizing antibody.

CONCLUSIONS

This work provides the methods for isolating and purifying mast cells and epithelial cells from human donor tissue and the opportunity for studying mechanisms of conjunctival inflammation by evaluating the interactions between these cells.

Epithelial cells are a major cellular source of the chemokine eotaxin in the guinea pig lung

Eotaxin is the major eosinophil chemoattractant found in bronchoalveolar lavage (BAL) fluid from sensitized guinea pigs after antigen challenge. In this study we have performed immunostaining for eotaxin in airways obtained from challenged animals and examined purified guinea pig lung cells (epithelial cells > 98% purity, mast cells > 90% purity) for eotaxin mRNA and protein. In the airways of antigen (ovalbumin) challenged animals, significant amounts of epithelial cell eotaxin immunostaining were observed. Northern analysis of total RNA obtained from unchallenged, freshly isolated airway epithelial cells contained high levels of eotaxin mRNA. Semi-pure and high purity lung mast cell preparations (challenged or unchallenged) did not express eotaxin mRNA. Western analysis of supernatant fluids obtained from incubated airway epithelial cells demonstrated detectable amounts of eotaxin protein, with the majority of the protein being cell-associated. Thus, airway epithelial cells are identified as a major cellular source of eotaxin in the guinea pig pulmonary system.

[Determination of urinary excretion of iodine in cordarone induced hyperthyroidism]

It is well known that amiodarone, an antiarrythmic drug containing iodine, can induce in some subjects thyroid function alterations: hyperthyroidism in patients resident in iodine-deficient areas and hypothyroidism in those with sufficient iodine intake. We attempted in this study to show the possibility to select the subjects at major risk of this iodine-induced hyperthyroidism, with a simple and inexpensive method such as urinary excretion iodine assay.

Isolation and purification of functional bovine lung mast cells (BLMCs)

Purified pulmonary mast cells were obtained from bovine lung using a combination of enzymatic digestion of tissue, density gradient centrifugation using Percoll, and centrifugal elutriation. In the initial procedure, lung tissue was enzymatically digested with collagenase, hyaluronidase, protease and elastase in three 30 min incubations at 37 degrees C. Monodispersed cell suspensions contained between 2 and 6% mast cells. Further purification of these mast cells by Percoll gradients and elutriation consistently yielded mast cells of > 90% purity. These cells were morphologically intact, viable and functional, as determined by histamine release evoked by secretagogue challenge. Incubation of BLMCs with Pasteurella haemolytica A1 culture supernate containing leucotoxin (LCT) alone, resulted in increased histamine release compared to controls. LCT also potentiated calcium ionophore (CaI)-induced histamine release from BLMCs.

Adrenal insufficiency in the antiphospholipid antibody syndrome

OBJECTIVE

Adrenal insufficiency (AI) is a rare complication of the antiphospholipid antibody syndrome (APS). The objective of this report is to describe a case and review the published literature to enhance recognition of this potentially fatal disorder by emphasizing its course, diagnosis, and cause.

DATA SOURCES

A bibliographic database with the indexing terms adrenal insufficiency, adrenal hemorrhage, adrenal thrombosis, APS, systemic lupus erythematosus, with the constraints of human subjects only, was used.

STUDY SELECTION

All 27 reports meeting the indexing terms were selected for review.

DATA EXTRACTION

The specific criteria used for data extraction articles included course of the disease, causation, clinical and laboratory diagnostic criteria, and therapeutic intervention.

DATA SYNTHESIS

Our patient is a previously health woman who developed a respiratory tract infection, followed by a prolonged illness with fever, hypotension, nausea, depression, and venous thromboses. She was found to have AI and APS that was alleviated with hydrocortisone and anticoagulation. Initially, her adrenal glands were normal on CT scan but subsequently became enlarged and later atrophic. Of the 27 previous case reports, a majority had thromboses and typical clinical and laboratory manifestations of AI. Hemorrhagic infarction of the adrenal gland appears to be the mechanism for AI in the APS. IgG and IgM anticardiolipin antibodies are most commonly reported in association with AI in APS.

CONCLUSIONS

The hypercoagulable state in the APS may lead to adrenal vein thrombosis and subsequently to hemorrhagic necrosis of the adrenal gland. This complication of APS is important to recognize because it may be fatal if untreated.

Optimization and validation of an ELISA to measure specific guinea pig IgG1 antibody as an alternative to the in vivo passive cutaneous anaphylaxis assay

Assessment of the allergenic potency of enzymes involves the use of a guinea pig model in which specific IgG1 antibody titers are used as the endpoint. The in vivo passive cutaneous anaphylaxis (PCA) assay is used to measure specific IgG1 antibody. This report describes the development and validation of an enzyme-linked immunosorbent assay (ELISA) to measure guinea pig specific IgG1 antibody as an in vitro alternative to the PCA assay. Cross reactivity of various rabbit and mouse (monoclonal) anti-guinea pig IgG1 preparations were evaluated using purified IgG1 and IgG2 from serum of guinea pigs immunized with ovalbumin. The two subclasses of guinea pig IgG were purified by first using Protein A affinity chromatography, followed by anion exchange chromatography and fluid phase isoelectric focusing. Affinity-purified rabbit anti-guinea pig IgG1 was shown to have minimal cross reactivity toward IgG2, while providing a strong signal with IgG1. The ELISA was designed as an antigen capture system in which the following are added in sequence: (1) enzyme antigen (passively adsorbed to the plate), (2) diluted serum samples from guinea pigs immunized with enzyme, (3) affinity-purified rabbit anti-guinea pig IgG1, (4) alkaline phosphatase-conjugated donkey anti-rabbit IgG, and (5) p-nitrophenyl phosphate substrate. Three replicate ELISA and PCA analyses were conducted on sera samples of varying titers from guinea pigs immunized with either Alcalase (protease), BPN' (protease), and Termamyl (amylase) enzyme. The correlation coefficients (r2) between the ELISA and PCA assay for Alcalase, BPN', and Termamyl were 0.826, 0.945, and 0.755, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison of the effects of isoproterenol and forskolin on immunologic and nonimmunologic release of histamine from guinea-pig superfused trachea and dispersed tracheal cells

This study has compared the abilities of isoproterenol and forskolin to inhibit immunologic- and nonimmunologic-induced histamine release from guinea-pig superfused trachea and enzymatically dispersed tracheal cells. Contraction was also measured in the former preparation. The potency of isoproterenol was similar for inhibition of all parameters associated with immunologic (ovalbumin) challenge in the two preparations. In contrast, forskolin appeared less potent in inhibiting ovalbumin-induced histamine release from dispersed tracheal cells. Histamine release by the nonimmunologic secretagogues d-tubocurarine and compound 48/80 was not altered by either substance. However, inhibition by isoproterenol and forskolin of tracheal contraction was evident when challenge was conducted with d-tubocurarine and compound 48/80. Inhibition of contraction appears to be a result of functional antagonism at the level of the smooth muscle. The superfused trachea is a useful preparation in which to explore the effects of substances that modulate mast cell mediator release.

2-LTR circular viral DNA as a marker for human immunodeficiency virus type 1 infection in vivo

The unintegrated viral DNA found in human immunodeficiency virus type 1 infection includes linear and circular forms. We targeted the circular form containing two copies of the viral long terminal repeat (2-LTR circle) and developed specific assays to detect this molecule in peripheral blood mononuclear cells from HIV-infected patients. In vitro HIV-1 infection of peripheral blood mononuclear cells showed rapid accumulation and rapid decay of 2-LTR circular viral DNA. Examination of 2-LTR circular viral DNA levels provides a view of spreading infection based on a viral DNA form that is structurally distinct and has a known, short half-life in infected cells. In patients not receiving antiviral therapy, the levels of 2-LTR circular viral DNA and total viral DNA were significantly correlated to CD4 cell counts. Similar correlations were not observed in patients receiving zidovudine (AZT), didanosine (ddA), or zalcitabine (ddC).

In vitro passive sensitization of guinea pig, rhesus monkey and human bladders as a model of noninfectious cystitis

Studies of human bladder inflammation have been limited to examination of urine, bladder biopsy, or examination of autopsy material. We have developed an in vitro bladder passive sensitization technique which can measure type I responses of isolated human bladder tissue. We have compared these results using human tissue to those obtained with bladder tissue from guinea pigs and Rhesus monkeys. In our studies, bladder tissue was passively sensitized in vitro for 20 hours with immunoglobulin-containing serum. Subsequent antigen challenge of the passively sensitized tissue resulted in a time-dependent contraction that was accompanied by tissue histamine release. Contractions of guinea pig, monkey and human bladder tissue reached 79%, 100% and 78% of the maximal contraction induced by potassium chloride. In contrast, adjacent strips of unsensitized tissue had no detectable response to antigen challenge. The responses were reduced in the presence of histamine H1 receptor blockade with pyrilamine and abolished in the presence of a concomitant blockade of leukotriene synthesis with nordihydroguaiaretic acid (NDGA). Blockade of cyclooxygenase activity with indomethacin increased the contraction of the sensitized guinea pig bladder in response to antigen challenge. These findings demonstrate that in vitro passive sensitization of human bladder tissue can be used to investigate basic mechanisms of noninfectious bladder inflammation in humans.

[Iodine deficiency diseases and pregnancy]

Iodine is a fundamental element of diet since it is important in thyroid hormone biosynthesis. Dietary iodine deficiency can provoke not only thyroid enlargement, but also symptoms and signs of hypothyroidism of various degree, known as "iodine deficiency disorders" (IDD). Thus, the iodine supplementation is mandatory. It can be obtained, in our regions, where subendemic deficiency is frequent, by adding iodine to salt. This is the only way to avoid anatomo-functional lesions, that are dramatic in pregnancy and childhood.

Differential release of prostaglandins and leukotrienes by sensitized guinea pig urinary bladder layers upon antigen challenge

The relative contributions of mucosal/submucosal and detrusor layers to the release of inflammatory mediators were investigated in isolated, ovalbumin (OVA) sensitized guinea pig urinary bladders. Ovalbumin challenge of sensitized mucosa induced release of prostaglandins (PG): PGE2, PGD2 and PGF2 alpha, in that order of magnitude. The total release of PGs was significantly higher from the mucosa/submucosa than from the detrusor/serosa. Under the same conditions, net release of leukotriene (LT) was observed predominantly from the detrusor. The total amount of histamine released from the mucosa was greater than that from the muscle layer. These results indicate differential production and release of inflammatory mediators from the mucosal/submucosal and detrusor smooth muscle layers. These results may have serious implications in disorders, such as interstitial cystitis, involving bladder mucosal damage. The cytoprotective effect of PGE2 is likely to be lost when the mucosa is damaged, and LT release from deeper layers may contribute significantly to symptoms of bladder inflammation.

Inhibition of aromatase activity in rat Sertoli cells by thyroid hormone

Basal and FSH-induced aromatase activity in prepubertal rat Sertoli cells was inhibited by L-triiodothyronine (T3) in a time- and dose-dependent manner. The effect was evident only after 6 h of preincubation with T3 (10(-7) M) and the half-maximal dose was 0.5 +/- 0.2 nM, which correlated with the Kd of the nuclear T3 receptor of rat Sertoli cells (Kd = 1-2 nM). The effect was specific as judged by the lack of effect of the T3 analogue 3-iodo-L-tyrosine. The inhibitory effect of T3 was present over the entire range of FSH concentrations used (0.001-100 ng/ml). In T3-treated Sertoli cells, aromatase activity induced by 8-bromo-cyclic AMP was inhibited by the same order of magnitude as that of FSH, thus suggesting that the inhibitory effect of T3 was downstream from cyclic AMP formation. Furthermore, pretreatment of Sertoli cells cultures with T3 (24 h, 10(-7) M) did not affect basal or FSH-induced extracellular cyclic AMP accumulation. This effect of T3 on rat Sertoli cell aromatase activity may be regarded as a part of the integrated mechanism by which thyroid hormone modulates the functions of the seminiferous epithelium.

Peptidoleukotriene (pLT) release from guinea pig lung mast cells

Guinea pig lung mast cells can be isolated and purified to high purity. This has given us the opportunity to study in greater detail mediator release from these cells. Both immunologic (ovalbumin sensitized) and nonimmunologic (calcium ionophore, CaI) stimuli caused a dose-dependent release of histamine and pLT from monodispersed lung cells and highly purified lung mast cells. Examination of the time release curve for pLT revealed a 5-min lag in the release of this mediator and a peak release at 60 min after challenge with antigen. Verification of pLT release was obtained by use of the 5-lipoxygenase inhibitor A64077 (Zileuton). Pretreatment of lung mast cells with the 5-lipoxygenase inhibitor prevented release of pLT by either antigen or CaI but had no appreciable effect on histamine release (HR). The pulmonary mast cell appears to be an important contributor to pLT release in the guinea pig lung.

Rheumatoid arthritis. Importance of early diagnosis in long-term outcome

Rheumatoid arthritis is a common disorder that does not have the favorable outcome it was once thought to have. A detailed clinical history, thorough physical examination, and judicious use of serologic tests and radiologic studies should allow accurate diagnosis, even at an early stage. Traditional therapy can successfully improve short-term functional status but may not alter long-term outcome. Early, aggressive therapy may improve prognosis, but this approach must be further studied and, if attempted, should be done in consultation with a rheumatologist.

Munchausen's syndrome: the importance of a comprehensive medical history

Munchausen's syndrome was first described by Asher in 1951. Then Ireland, et al, described eight criteria that characterized these patients. These characteristics include factitious illness of a dramatic nature, factitious evidence of disease, evidence of multiple medical procedures, pathologic lying, aggressive behavior, leaving the hospital against medical advice, multiple hospitalizations with traveling and absence of any obvious secondary gain. Another form of this disease is Munchausen's syndrome by proxy which describes parental behavior that creates the appearance of, or produces, physical illness in a child with harmful consequences to the child. In this report, we present a complex case of Munchausen's syndrome in a patient who has been traveling around the country, going from one hospital to another for several years. We ask physicians to be aware of the features of this patient, bearing in mind that this was her third hospitalization at the University of Wisconsin Hospital in Madison.

Pharmacologic modulation of the influence of the epithelium on immunologic- and nonimmunologic-induced histamine release and contraction in guinea pig superfused tracheal strips

The influence of the epithelium on contractions and histamine release evoked by ovalbumin and d-tubocurarine has been examined in guinea pig superfused tracheal strips under several experimental conditions. Without drug pretreatment, removal of the epithelium resulted in larger (P < .05) total histamine released by ovalbumin, 10(-4) to 10(-1) mg/ml, and by d-tubocurarine, 3 x 10(-3) M. In the presence of indomethacin, 5 x 10(-6) M, epithelium removal resulted in elevated histamine release only at smaller ovalbumin concentrations, 10(-4) and 10(-3) mg/ml. Indomethacin did not change the influence of the epithelium on histamine release by d-tubocurarine. Indomethacin treatment abolished the influence of the epithelium on ovalbumin-induced tracheal contraction. With indomethacin, larger (P < .05) histamine release was seen with ovalbumin, 10(-1) and 1 mg/ml, when the epithelium was intact. The larger histamine release in response to ovalbumin, 10(-1) mg/ml, in the presence of the epithelium was unaltered by pyrilamine, 10(-6) M, cimetidine, 10(-4) M, and thioperamide, 10(-6) M, to block histamine H1, H2 and H3 receptors, respectively. Therefore, histamine released by ovalbumin does not stimulate histamine release through an action on these receptors when the epithelium is intact. In the presence, but not in the absence, of the epithelium, A64077, 10(-5) M, and ICI198615, 10(-8) and 10(-6) M, inhibitors of 5-lipoxygenase and LTD4/E4 receptors, respectively, inhibited histamine release by ovalbumin, 10(-1) mg/ml. Histamine release by ovalbumin, 10(-4) mg/ml, and d-tubocurarine, 3 x 10(-3) M, studied with or without epithelium was not altered by A64077 or ICI198615.(ABSTRACT TRUNCATED AT 250 WORDS)

Pharmacokinetic-interaction study of didanosine and ranitidine in patients seropositive for human immunodeficiency virus

The potential pharmacokinetic interactions between didanosine, an acid-labile antiretroviral agent, and ranitidine, an H2-receptor antagonist, were evaluated by a crossover study of 12 male patients seropositive for the human immunodeficiency virus. Single oral doses of 375 mg of didanosine, formulated as a citrate-phosphate-buffered sachet, or of 150 mg of ranitidine were administered alone or in combination (ranitidine was given 2 h prior to didanosine). Serial blood samples and total urinary output were collected after each treatment and analyzed for didanosine and/or ranitidine by validated high-performance liquid chromatography-UV assay methods. Pharmacokinetic parameters were calculated by noncompartmental methods. There were significant increases in mean area under the curve from time zero to infinity and mean urinary recovery for didanosine given in combination with ranitidine compared with those for didanosine alone. There were no significant differences between didanosine coadministered with ranitidine and didanosine alone in the respective mean peak concentrations in plasma, times to peak, elimination half-lives, or renal clearances. The mean area under the curve for ranitidine given with didanosine was significantly less than that for ranitidine given alone. There were no significant differences between the mean peak concentrations in plasma, times to peak, elimination half-lives, renal clearances, or urinary recovery values for ranitidine coadministered with didanosine and values for ranitidine given alone. These data demonstrate that administration of didanosine 2 h after ranitidine will result in a minor increase in the bioavailability of didanosine. A modification in the dose of didanosine or ranitidine is not necessary if the dose of ranitidine precedes that of didanosine by 2 h.

Human synovial mast cell involvement in rheumatoid arthritis and osteoarthritis. Relationship to disease type, clinical activity, and antirheumatic therapy

Mast cells were isolated by enzymatic digestion of synovium obtained from 48 patients with rheumatoid arthritis (RA) and 42 patients with osteoarthritis (OA). A significantly lower percentage of stainable synovial mast cells was obtained by tissue digestion from patients with clinically active RA compared with those with less active disease. The 54 patients treated with nonsteroidal antiinflammatory drugs had a significantly lower percentage of stainable synovial mast cells in cell suspension than did the other 36 patients. When anti-IgE antibody was used as a secretagogue in vitro, significantly greater histamine release was observed from synovial mast cells of RA patients compared with OA patients. Greater histamine release in response to anti-IgE was observed in the RA patients with more clinically active disease and those who were treated with prednisone, compared with RA patients without these features. Synovial mast cells of RA patients treated with a disease-modifying antirheumatic drug had a significantly lower mean histamine content than did cells from patients not receiving such treatment. Our data suggest that there are differences between synovial mast cells from tissues of patients with RA and OA and suggest that synovial mast cells may be activated in clinically active RA. In addition, the data indicate an effect of systemic antirheumatic therapy on mast cells isolated from synovium of patients with arthritis.

Drug induced polymyositis secondary to leuprolide acetate (Lupron) therapy for prostate carcinoma

Inflammatory myopathy has been associated with systemic inflammatory processes, endocrinopathies, malignancies and infections. Drug induced myopathies have been implicated with the use of several medications. We report a case of biopsy proven myositis whose symptoms began within 10 days of receiving leuprolide acetate therapy for prostate cancer. Drug withdrawal and brief steroid therapy resulted in clinical remission within two months of diagnosis.