LDHA mediated degradation of extracellular matrix is a potential target for the treatment of aortic dissection

Aortic dissection (AD) is a disease with high mortality and lacks effective drug treatment. Recent studies have shown that the development of AD is closely related to glucose metabolism. Lactate dehydrogenase A (LDHA) is a key glycolytic enzyme and plays an important role in cardiovascular disease. However, the role of LDHA in the progression of AD remains to be elucidated. Here, we found that the level of LDHA was significantly elevated in AD patients and the mouse model established by BAPN combined with Ang II. In vitro, the knockdown of LDHA reduced the growth of human aortic vascular smooth muscle cells (HAVSMCs), glucose consumption, and lactate production induced by PDGF-BB. The overexpression of LDHA in HAVSMCs promoted the transformation of HAVSMCs from contractile phenotype to synthetic phenotype, and increased the expression of MMP2/9. Mechanistically, LDHA promoted MMP2/9 expression through the LDHA-NDRG3-ERK1/2-MMP2/9 pathway. In vivo, Oxamate, LDH and lactate inhibitor, reduced the degradation of elastic fibers and collagen deposition, inhibited the phenotypic transformation of HAVSMCs from contractile phenotype to synthetic phenotype, reduced the expression of NDRG3, p-ERK1/2, and MMP2/9, and delayed the progression of AD. To sum up, the increase of LDHA promotes the production of MMP2/9, stimulates the degradation of extracellular matrix (ECM), and promoted the transformation of HAVSMCs from contractile phenotype to synthetic phenotype. Oxamate reduced the progression of AD in mice. LDHA may be a therapeutic target for AD.

Randomised Double-Masked Trial of Lodoxamide and Sodium Cromoglycate in Allergic Eye Disease

135 patients were entered into a 28-day randomized double-masked multicentre study comparing the efficacy and short-term safety of lodoxamide 0.1% ophthalmic solution (Alomide--Alcon Laboratories), a mast cell stabilizer, with sodium cromoglycate 2% ophthalmic solution (Opticrom--Fisons Pharmaceuticals) in the treatment of allergic eye disease. Patients given lodoxamide 0.1% showed a significantly more rapid and greater improvement in their signs and symptoms of allergic eye disease than patients given sodium cromoglycate 2%. Both treatments were found to be safe, and side-effect profiles were comparable between the two treatment groups, although the overall incidence of side-effects in this study was found to be less frequent in the lodoxamide-treated group.

Comparison of Topical 0.05% Levocabastine and 0.1% Lodoxamide in Patients with Allergic Conjunctivitis

Purpose

The aim of the study was to assess the efficacy and safety of 0.05% levocabastine eyedrops (H1 receptor blocker given BID + vehicle BID) compared with 0.1% lodoxamide ophthalmic solution (mast-cell stabilizer instilled QID) in reducing ocular signs and symptoms of allergic conjunctivitis.

Methods

A randomized, double-masked, parallel-group study was conducted in seven centres in France, in which 93 patients suffering from seasonal or perennial allergic conjunctivitis were randomly allocated to either 0.05% levocabastine (n = 47) or 0.1% lodoxamide (n = 46) in both eyes for a 14-day period. Efficacy was evaluated by subjective (prickling, burning, photophobia, itching) and objective (redness, chemosis, eyelid edema, tearing) sign scores at visits on days 7 and 14, and from data noted daily by the patient in a self-evaluation form. Safety was assessed as tolerance upon instillation and adverse event reports.

Results

The ocular allergy symptom and sign scores were comparable in the two treatment groups at baseline. With time, statistically and clinically significant reductions (p < 0.001) from baseline were observed for the subjective and objective scores, with no difference between the treatment groups. After the first instillation, signs were alleviated more rapidly in levocabastine-treated patients than in the lodoxamide group (p < 0.001). Overall assessments by the patient and investigator were similar in both groups. No serious adverse events were reported.

Conclusions

Levocabastine ophthalmic suspension 0.05% (BID) appears to be as effective and safe as lodoxamide 0.1% (QID) in the management of allergic conjunctivitis.

Oxamate Improves Glycemic Control and Insulin Sensitivity via Inhibition of Tissue Lactate Production in db/db Mice

Oxamate (OXA) is a pyruvate analogue that directly inhibits the lactate dehydrogenase (LDH)-catalyzed conversion process of pyruvate into lactate. Earlier and recent studies have shown elevated blood lactate levels among insulin-resistant and type 2 diabetes subjects and that blood lactate levels independently predicted the development of incident diabetes. To explore the potential of OXA in the treatment of diabetes, db/db mice were treated with OXA in vivo. Treatment of OXA (350–750 mg/kg of body weight) for 12 weeks was shown to decrease body weight gain and blood glucose and HbA1c levels and improve insulin secretion, the morphology of pancreatic islets, and insulin sensitivity in db/db mice. Meanwhile, OXA reduced the lactate production of adipose tissue and skeletal muscle and serum lactate levels and decreased serum levels of TG, FFA, CRP, IL-6, and TNF-α in db/db mice. The PCR array showed that OXA downregulated the expression of Tnf, Il6, leptin, Cxcr3, Map2k1, and Ikbkb, and upregulated the expression of Irs2, Nfkbia, and Pde3b in the skeletal muscle of db/db mice. Interestingly, LDH-A expression increased in the islet cells of db/db mice, and both treatment of OXA and pioglitazone decreased LDH-A expression, which might be related to the improvement of insulin secretion. Taken together, increased lactate production of adipose tissue and skeletal muscle may be at least partially responsible for insulin resistance and diabetes in db/db mice. OXA improved glycemic control and insulin sensitivity in db/db mice primarily via inhibition of tissue lactate production. Oxamic acid derivatives may be a potential drug for the treatment of type 2 diabetes.

Trypanocidal effect of the benzyl ester of N-propyl oxamate: a bi-potential prodrug for the treatment of experimental Chagas disease

BACKGROUND

Chagas disease, which is caused by Trypanosoma cruzi, is a major health problem in Latin America, and there are currently no drugs for the effective treatment of this disease. The energy metabolism of T. cruzi is an attractive target for drug design, and we previously reported that inhibitors of α-hydroxy acid dehydrogenase (HADH)-isozyme II exhibit trypanocidal activity. N-Propyl oxamate (NPOx) is an inhibitor of HADH-isozyme II, and its non-polar ethyl ester (Et-NPOx) is cytotoxic to T. cruzi. A new derivative of NPOx has been developed in this study with higher trypanocidal activity, which could be used for the treatment of Chagas disease.

METHODS

The benzyl ester of NPOx (B-NPOx) was synthesized and its activity evaluated towards epimastigotes and bloodstream trypomastigotes (in vitro), as well as mice infected with T. cruzi (in vivo). The activity of B-NPOx was also compared with those of Et-NPOx, benznidazole (Bz) and nifurtimox (Nx). NINOA, Miguz, Compostela, Nayarit and INC-5 T. cruzi strains were used in this study.

RESULTS

Polar NPOx did not penetrate the parasites and exhibited no trypanocidal activity. In contrast, the hydrophobic ester B-NPOx exhibited trypanocidal activity in vitro and in vivo. B-NPOx exhibited higher trypanocidal activity than Et-NPOx, Bz and Nx towards all five of the T. cruzi strains. The increased activity of B-NPOx was attributed to its hydrolysis inside the parasites to give NPOx and benzyl alcohol, which is an antimicrobial compound with trypanocidal effects. B-NPOx was also effective against two strains of T. cruzi that are resistant to Bz and Nx.

CONCLUSION

B-NPOx exhibited higher in vitro (2- to 14.8-fold) and in vivo (2.2- to 4.5-fold) trypanocidal activity towards T. cruzi than Et-NPOx. B-NPOx also exhibited higher in vitro (2- to 24-fold) and in vivo (1.9- to 15-fold) trypanocidal activity than Bz and Nx. B-NPOx is more lipophilic than Et-NPOx, allowing for better penetration into T. cruzi parasites, where the enzymatic cleavage of B-NPOx would give NPOx and benzyl alcohol, which are potent trypanocidal agents. Taken together with its low toxicity, these results suggest that B-NPOx could be used as a potent prodrug for the treatment of Chagas disease.

Promoted interaction of nuclear factor-κB with demethylated cystathionine-β-synthetase gene contributes to gastric hypersensitivity in diabetic rats

Patients with long-standing diabetes frequently demonstrate gastric hypersensitivity with an unknown mechanism. The present study was designed to investigate roles for nuclear factor-κB (NF-κB) and the endogenous H2S-producing enzyme cystathionine-β-synthetase (CBS) signaling pathways by examining cbs gene methylation status in adult rats with diabetes. Intraperitoneal injection of streptozotocin (STZ) produced gastric hypersensitivity in female rats in response to gastric balloon distention. Treatment with the CBS inhibitor aminooxyacetic acid significantly attenuated STZ-induced gastric hypersensitivity in a dose-dependent fashion. Aminooxyacetic acid treatment also reversed hyperexcitability of gastric-specific dorsal root ganglion (DRG) neurons labeled by the dye DiI in diabetic rats. Conversely, the H2S donor NaHS enhanced neuronal excitability of gastric DRG neurons. Expression of CBS and p65 were markedly enhanced in gastric DRGs in diabetic rats. Blockade of NF-κB signaling using pyrrolidine dithiocarbamate reversed the upregulation of CBS expression. Interestingly, STZ treatment led to a significant demethylation of CpG islands in the cbs gene promoter region, as determined by methylation-specific PCR and bisulfite sequencing. STZ treatment also remarkably downregulated the expression of DNA methyltransferase 3a and 3b. More importantly, STZ treatment significantly enhanced the ability of cbs to bind DNA at the p65 consensus site, as shown by chromatin immunoprecipitation assays. Our findings suggest that upregulation of cbs expression is attributed to cbs promoter DNA demethylation and p65 activation and that the enhanced interaction of the cbs gene and p65 contributes to gastric hypersensitivity in diabetes. This finding may guide the development and evaluation of new treatment modalities for patients with diabetic gastric hypersensitivity.

Safety and efficacy of lodoxamide in vernal keratoconjunctivitis

OBJECTIVE

To observe the safety and efficacy of topical Lodoxamide eye drops in patients with diagnosed vernal keratoconjunctivitis (VKC).

METHODS

This study was conducted at Department of Pharmacology and Therapeutics, BMSI, JPMC, Karachi in collaboration with Department of Ophthalmology, JPMC, Karachi, from April to October, 2009. A total of forty patients with diagnosed vernal keratoconjunctivitis were selected and enrolled consecutively from the out patient department (OPD) of Ophthalmology. Each patient received two drops of Lodoxamide eye drops topically in each eye four times daily. Patients were examined with a torch and slit lamp at baseline and follow-up visits.

RESULTS

Out of 40 patients included, 39 completed the study and there was a significant effect of the drug on symptoms and signs of the disease. At the end of the study, 38 (97.4%) were cured, with few side effects. The cure criteria was based on patient's history of becoming symptom-free and resolution of ocular signs.

CONCLUSION

Topical lodoxamide eye drops, when used for treatment of VKC, are effective with fewer adverse effects.

Secondary Bacterial Keratitis Associated With Shield Ulcer Caused by Vernal Conjunctivitis

PURPOSE

To report a patient with vernal keratoconjunctivitis-induced shield ulcer superinfected with Staphylococcus aureus.

METHODS

Observational case report. A 12-year-old boy who had been followed for vernal keratoconjunctivitis for 3 years was admitted to our clinic complaining of visual loss, photophobia, and a ropy discharge. On slit-lamp examination, a transversely oval shield ulcer, which was situated in the center of the superior third of the cornea, was seen in the left eye. The vernal corneal plaque area and margins were infiltrated, and hypopyon was also observed. With the diagnosis of shield ulcer with secondary bacterial keratitis and hypopyon, the patient underwent medical treatment consisting of topical fortified cefazolin (50 mg/mL) and tobramycin (14 mg/mL), lodoxamide 0.1%, prednisolone acetate 1%, cyclopentolate, and systemic cetirizine.

RESULTS

After treatment, the bacterial keratitis, shield ulcer, and inflammation in the anterior chamber disappeared.

CONCLUSION

Bacterial keratitis associated with shield ulcer may be rarely observed in patients with vernal keratoconjunctivitis. Prompt diagnosis and treatment may prevent permanent complications and vision loss.

[Evaluation of the efficacy and safety of lodoxamide in patients with allergic eye diseases]

PURPOSE

To evaluate the effectiveness of lodoxamide in the therapy and prophylaxis of the ocular allergies.

PATIENTS AND METHODS

This prospective study included 64 patients divided in 2 groups. In the first group there were 47 symptomatic patients suffering from seasonal allergic conjunctivitis (n = 27), perennial allergic conjunctivitis (n = 16) and giant papillary conjunctivitis (n = 4). The symptomatic patients were examined upon arrival and every 2 weeks until the symptoms were reduced. During the period, lodoxamide drops were administered 4 times a day. In the second group there were 17 patients who had a history of seasonal ocular allergies during previous years but were still not symptomatic upon arrival. In the group of 17 patients who were very likely to develop ocular allergy but up to inclusion into the study had no ocular symptoms, 12 (70%) presented with allergic rhinitis while 5 (30%) had asthma. The symptoms intensity (itching, discomfort, foreign body sensation, pain, tearing) was graded on a 0-3 scale. The clinical signs (follicles, papillae, hyperemia, conjunctival edema, Trantas dots, stromal infiltrates) were detected on a slit lamp examination and graded on a 0-3 scale.

RESULTS

In the group of 47 symptomatic patients 2-4 weeks after lodoxamide administration, 70-80% of symptomatic patients examined clinically had less or no follicles, 60-70% had reduced or no edema, the secretion was stopped or greatly reduced in 50-70% of patients. All of the patients reported reduced or no itching, 60% of patients reported less discomfort, photophobia and reduced tearing. In the asymptomatic group two weeks after the initiation of the prophylaxis 88% of patients were still with no ocular signs of allergy while 12% of patients had a conjunctival hyperemia and follicles. After 4 weeks of the prophylaxis 76% of patients patients were still asympthomatic while only 4 developed a mild form of allergic conjunctivitis (conjunctival hyperemia and papillae), but less severe than during previous episodes.

CONCLUSION

Lodoxamide was effective in reduction of symptoms and clinical signs of the ocular allergies. The best results were obtained if the drug was administered as a prophylaxis or very early in the course of the disease.

[Evaluation of efficacy and safety of sterile solution of lodoxamide in patients with ocular allergy]

PURPOSE

Evaluating the efficiency and safety of Alomide (lodoxamide 01.%) in the treatment of allergic conjunctivitis. MATERIAL, METHOD: 12 patients have been selected during may-august 1998, in order to be treated with Alomide 4 times daily. The clinical exam of the patient included: general information, history, ocular examination. The ocular status of each patient has been evaluated with a score: the intensity of each symptom and sign has been graded between 1-3.

RESULTS

In all cases, the use of Alomide induced the improvement of the typical symptoms and signs of the allergic conjunctivitis. No side effect related to the use of the drug has been noted.

CONCLUSION

Due to its dual action (inhibition of both mast cells and eosinophils), Alomide covers most of the allergic response.

Lodoxamide as adjuvant therapy in patients with dry eye

Dry eye, due to its impaired function of tear film becomes more susceptible to all kinds of airborne allergens. Due to air pollution this is more marked in urban areas, and is compounded by the modern way of life. There are various standard topical medications which alleviate allergic reaction of the eye, but many of them must be administered with caution and only on short term due to their potentially hazardous side effects. The purpose of this work is to assess the efficacy of lodoxamide, a new antiallergic medication for topical use, whose advantage is low or absent risk of adverse side effects, in alleviating local allergic reactions of the eye in patients with dry eye. Research has shown that, compared to treatment with eye lubricants alone (artificial tears), treatment with artificial tears combined with lodoxamide has resulted in more marked decrease in the signs of inflammation, and to the lesser extent to the reduction of the symptoms as well.

Comparison of lodoxamide 0.1% ophthalmic solution and levocabastine 0.05% ophthalmic suspension in vernal keratoconjunctivitis

PURPOSE

To compare the clinical efficacy and safety of lodoxamide 0.1% ophthalmic solution with levocabastine 0.05% ophthalmic suspension, each given four times daily (QID) for three months to patients with vernal keratoconjunctivitis (VKC).

METHODS

The study was conducted multinationally according to a triple-masked parallel design in 95 VKC patients, with assessments at baseline then monthly during the three months of treatment. The primary efficacy variables were a Physician's Clinical Judgement Scale and a Patient's Overall Judgement Scale of improvements from baseline. Signs and symptoms of VKC were also assessed.

RESULTS

Both primary efficacy variables showed significantly greater overall improvement of VKC from baseline with lodoxamide than levocabastine. The superiority of lodoxamide was demonstrated by the Physician's Clinical Judgement Scale at months 2 and 3, with a trend, at month 1, and by the Patient's Overall Judgement Scale at months 1, 2 and 3. All signs and symptoms of VKC improved significantly from baseline at all time points, regardless of treatment (p<0.001). However, relative to levocabastine, conjunctival discharge, photophobia and lacrimation were significantly reduced by lodoxamide at months 1, 2 and 3, itching at months 2 and 3, and bulbar conjunctiva at month 3. The temporal improvement of superior tarsal papillae did not differ significantly between treatments. Both were well tolerated.

CONCLUSIONS

Lodoxamide 0.1% and levocabastine 0.05% eye drops, instilled four times daily for three months, were effective, safe and well tolerated by patients with VKC, but lodoxamide was significantly superior to levocabastine.

[An efficacy study of lodoxamide treatment in allergic eye lesions]

Lodoxamid is an antiallergic drug, which stabilizes the mast cells' membrane blocking the release of the type I hypersensitivity reaction chemical mediators. A number of 25 patients with ocular allergic diseases (allergic conjunctivitis, vernal and atopic keratoconjunctivitis, giant papillary conjunctivitis), were included in this study. Lodoxamid, solution 0.1% (Alomide), was given 4 times daily for 6 weeks. The study's aim was to assess the lodoxamid's efficiency, on the ocular signs and symptoms. The study's results showed a significant improvement, or the disappearance of the ocular allergic disease. It is debated upon the lodoxamid's way and place of action, in blocking the type I hypersensitivity reaction. The lodoxamid's efficiency is due to its pharmacological features, by means of which it is effective on many links of the pathogenic chain: mast cells, eosinophils, lymphocytes, neutrophils, antigen presenting cells. Due to its action lodoxamid stabilizes the mast cell's membrane, and inhibits the release of histamine, prostaglandins, leukotrienes, triptase, interleukines -4, -8 and TNF-. During therapy with lodoxamid recruitment and activation of eosinophils is decreased, causing a significant reduction of the basic major protein, cationic eosinophilic protein, eosinophilic derived neurotoxin, eosinophilic peroxidase. Lodoxamid reduces the expression of ICAM-1 on the surface of the antigen presenting cells, and decreases the number of the TH2 cells, from the tears of the allergic patients.

Pharmacological mechanism of topical lodoxamide treatment in vernal keratoconjunctivitis: a flow-cytometric study

The aim of this study was to investigate the possible effect of lodoxamide 0.1% ophthalmic solution (LOS) on tear T lymphocytes, especially Th2 (T helper 2 subgroup of helper T lymphocytes), in the tear specimens of patients with vernal keratoconjunctivitis (VKC) and to explore the mechanism of the anti-allergic effect of this drug. Twenty-eight active VKC patients were randomly divided into two groups each containing 14 patients. We obtained tear samples from all patients at the beginning of the study. LOS was prescribed to the study group (group A), but the controls (group B) received placebo over the course of 6 weeks. Tear samples were also collected from all patients following a 6-week course of treatment with either LOS or placebo. The percentages of Th1, Th2 and Th cells in the tear samples were measured by using a flow-cytometric technique and the results were compared to each other by using Wilcoxon matched-pairs signed-rank and Mann-Whitney U tests. We found that LOS treatment decreased the percentages of Th2 and Th cells in the tears of group A patients, while placebo had no effect on these values. Th1 cell count in the tears of both groups of patients did not show any significant change between the pre- and posttreatment stages. Our data suggest that LOS exerts, at least, some part of its anti-allergic effect via decreasing the Th2 cell number in the tears of VKC patients.

Contrast of the effect of alomide and sodium cromoglycate in the treatment of allergic eye diseases

PURPOSE

To observe the clinical effect of alomide and sodium cromoglycate eyedrops in the treatment of atopic conjunctivitis, vernal conjunctivitis and giant papillary conjunctivitis.

METHODS

Randomized control study was used. Alomide and sodium cromoglycate eyedrops used to treat two groups of patients for two weeks. The effects of the two groups were compared.

RESULTS

With respect of comprehensive therapeutic effect, the effectiveness rate was 83.6% in alomide group, and 63.3% in sodium cromoglycate group, which was not significantly different statistically. With respect of itching alleviation, alomide is more effective than sodium cromoglycate. No adverse effects were found in both groups.

CONCLUSION

Our study suggests that alomide is a safe and effective drug in the treatment of allergic conjunctivitis.

The role of mast cells in ischaemia-reperfusion injury in murine skeletal muscle

To determine the role of mast cells in ischaemia-reperfusion (IR) injury to skeletal muscle, W(f)/W(f) mast cell-deficient and their corresponding wild-type mice were subjected to 70 min tourniquet ischaemia and 24 h reperfusion. As measured by nitroblue tetrazolium (NBT) staining, muscle viability was 9% in wild-type and 94% in mast cell-deficient animals (p<0.001). Assay of residual lactate dehydrogenase activity within the injured muscle (p<0.05) and histological examination confirmed the greater muscle necrosis in treated wild-type than in treated mast cell-deficient mice. There was no significant difference in the degree of neutrophil infiltration, tissue myeloperoxidase content or water content of IR-injured muscle in the two mouse phenotypes. To determine further the role of mast cells in IR injury, wild-type mice were treated 30 min prior to reperfusion with an intraperitoneal dose of either saline or the mast cell-stabilizing agent lodoxamide trometamol (2.5, 7.5, 25 or 75 mg/kg). Twenty-four hours after removal of the tourniquet, saline-treated gastrocnemius muscle had a mean viability of 14% compared with 28% (p<0.05) and 48% (p<0.01) after 25 mg/kg and 75 mg/kg of lodoxamide treatment, respectively. The ability of lodoxamide to stabilize mast cells was confirmed by histological examination. Ischaemic muscle reperfused for 1 h showed much less degranulation of mast cells in mice pretreated with lodoxamide (50 mg/kg) than in saline-treated controls. These findings suggest that mast cells are a major source of mediators of necrosis in IR injury to skeletal muscle.

Mechanisms and comparison of anti-allergic efficacy of topical lodoxamide and cromolyn sodium treatment in vernal keratoconjunctivitis

PURPOSE

To explore the mechanism of action of topical lodoxamide and cromolyn sodium treatment in vernal keratoconjunctivitis (VKC) and to compare the efficacy of these drugs to each other.

DESIGN

Single-investigator, masked, randomized, clinical trial.

PARTICIPANTS

Twenty male and 10 female patients between the ages of 6 and 19 years, who were diagnosed as having active VKC, were enrolled in this study.

INTERVENTIONS

The patients were randomly divided into two equal groups (groups A and B). Group A patients received topical lodoxamide ophthalmic solution 0.1% (LOS); topical cromolyn sodium ophthalmic solution 4% (CSO) was prescribed to group B patients in a dose of two drops four times daily.

MAIN OUTCOME MEASURES

The eye symptom severity scores and clinical signs of the patients were evaluated both in the pre- and post-treatment periods. In addition to the clinical data, conjunctival impression cytologic specimens were obtained from patients both before and after treatment. Impression cytologic specimens were stained using immunohistochemical methods to detect the percentages of CD4(+), CD8(+), CD45RA(+), and CD23(+) cells. Statistical analyses were performed within and between groups.

RESULTS

The percentages of CD4(+) and CD23(+) cells in tear samples of patients in groups A and B were significantly higher in the pretreatment stage than post-treatment stage. In the post-treatment stage, group A patients had significantly lower CD4(+) and CD23(+) cell values compared with group B patients. Patient symptom scores and clinical signs were at a significantly lower level after treatment with either LOS or CSO in both groups A and B compared with their pretreatment values. Moreover, group A patients had significantly lower symptom scores and clinical signs than group B patients in the post-treatment stage.

CONCLUSIONS

Clinical superiority of LOS over CSO may be linked to its greater effect on the CD4(+) cells, because CD4(+) cells plays a pivotal role in the pathogenesis of VKC.

Efficacy of lodoxamide eye drops on tear fluid cytology of patients with vernal conjunctivitis

A double-masked, randomized, placebo-controlled study was conducted to evaluate the effectiveness of lodoxamide tromethamine 0.1% eyedrops in preventing inflammatory cell accumulation in the tear fluid of patients with vernal conjunctivitis. A 1-week baseline period was followed by 4 weeks of treatment with either lodoxamide tromethamine 0.1% ophthalmic solution or placebo in 30 symptomatic subjects with vernal conjunctivitis. Cytological evaluation of tear fluid was performed before and after the treatment. In the lodoxamide-treated group, but not in the placebo-treated group, the number of neutrophils (P = 0.051) and eosinophils (P = 0.020) in the tears significantly decreased at the end of 4 weeks when compared with baseline (Wilcoxon-signed rank test). It was concluded that lodoxamide treatment was significantly more effective than the placebo in terms of reducing inflammatory cells in the tear fluid in vernal conjunctivitis. This objective inhibition of inflammatory cells may be associated with clinical relief.

Lacrimal occlusion therapy for the treatment of superior limbic keratoconjunctivitis

Superior limbic keratoconjunctivitis (SLK) is a chronic and recalcitrant disease of the superior bulbar and tarsal conjunctiva, as well as the superior limbic aspect of the cornea. Both the etiology and the pathogenesis of this condition are poorly understood. Many treatment options have been advocated in the management of SLK, including: topical antibiotics, topical anti-inflammatory agents, topical vitamin A solutions, chemical cautery, thermal cautery, and surgical resection. Most recently, studies have suggested that lacrimal occlusion therapy may be beneficial in the treatment of SLK. A case is presented in which this method of treatment was used, with excellent results. The implications of this report suggest that the use of lacrimal occlusion in the management of SLK may be a viable treatment option before considering more radical and invasive therapy. In addition, this case helps to illustrate the significant link between SLK and thyroid disease.

Treatment of common ocular allergic disorders; a comparison of lodoxamide and NAAGA

BACKGROUND/AIMS

Lodoxamide tromethamine and N-acetyl-aspartyl glutamic acid (NAAGA) are mast cell stabilisers, both of which have been shown to be effective in the treatment of allergic conjunctivitis. The aim of this study was to compare the two compounds in patients with common ocular allergic disorders.

METHODS

73 patients participated in a double masked, randomised multicentre study. Diagnoses were chronic allergic conjunctivitis, vernal conjunctivitis, seasonal and atopic conjunctivitis. 36 patients were treated with lodoxamide 0.1% and 37 with NAAGA 4.9%, the drops being instilled four times daily for up to 56 days.

RESULTS

The overall opinion of the physicians and the patients was in favour of lodoxamide at day 10 of the study. At this time, 86% of lodoxamide treated and 49% of NAAGA treated patients considered they had improved. The patients' opinion favoured lodoxamide at day 28 and both physicians' and patients' evaluations were in favour of lodoxamide at day 42. Evaluation of signs and symptoms indicated superiority of lodoxamide at days 42 and 56. Both treatments were well tolerated.

CONCLUSION

While both lodoxamide and NAAGA treatments are associated with clinical improvements in patients with allergic conjunctivitis, lodoxamide may have an earlier onset of action.

Effect of lodoxamide on tear leukotriene levels in giant papillary conjunctivitis associated with ocular prosthesis

Leukotrienes have been shown to play a role in the pathogenesis of ocular inflammatory and allergic reactions like vernal keratoconjunctivitis and contact lens-associated giant papillary conjunctivitis. This study was designed to determine leukotriene B4 (LTB4) and leukotriene C4 (LTC4) levels in the tears of patients with ocular prosthesis-associated giant papillary conjunctivitis (OP-GPC) and to evaluate the effects of lodoxamide 0.1% on tear LTB4 and LTC4 levels of OP-GPC patients. Tear LTB4 and LTC4 levels were determined by an ELISA technique in the tears of ten OP-GPC patients before and after treatment with lodoxamide 0.1% for one month. The results were compared with that of ten healthy control subjects. The mean tear LTB4 and LTC4 levels of the OP-GPC patients were significantly higher than those of the control group. After treatment with lodoxamide 0.1%, tear LTB4 and LTC4 levels of the OP-GPC patients decreased significantly. This is the first report of elevated LTB4 and LTC4 levels in tears of OP-GPC patients and it points to the possible role of leukotrienes in the immunopathogenesis of OP-GPC. The results also indicate that lodoxamide 0.1%, a mast cell membrane stabilizer, is effective in significantly reducing tear LTB4 and LTC4 levels in OP-GPC patients.

Effects of lodoxamide, disodium cromoglycate and fluorometholone on tear leukotriene levels in vernal keratoconjunctivitis

PURPOSE

We compared tear leukotriene B4 (LTB4) and leukotriene C4 (LTC4) levels of vernal keratoconjunctivitis (VKC) patients with those of age-matched controls and evaluated the effects of disodium cromoglycate (DCG) 2%, lodoxamide 0.1% and fluorometholone 0.1% on the tear LTB4 and LTC4 levels of the VKC patients.

METHODS

Thirty VKC patients were divided into three groups and their tear LTB4 and LTC4 levels measured with an enzyme-linked immunoassay technique before and after treatment with either lodoxamide 0.1%, DCG 2% or fluorometholone 0.1%. The results were compared with the tear LTB4 and LTC4 levels of 10 healthy control subjects. During this trial period, clinical scores for signs and symptoms of VKC were also evaluated.

RESULTS

In the VKC patients median tear LTB4 and LTC4 levels were 349.0 pg/ml (range 213.3-707.7 pg/ml) and 225.2 pg/ml (range 196.1-241.1 pg/ml) respectively--significantly higher than the control group (p = 0.0065 for LTB4 and p = 0.0003 for LTC4). After treatment, LTB4 levels decreased significantly in all treatment groups when compared with baseline (for the lodoxamide group, p = 0.01; for the DCG group, p = 0.008; for the fluorometholone group, p = 0.045). LTC4 levels were also significantly reduced after treatment in all three treatment groups (for the lodoxamide group, p = 0.0209; for the DCG group, p = 0.0284; for the fluorometholone group, p = 0.0109).

CONCLUSIONS

Tear LTB4 and LTC4 levels are significantly higher in VKC patients than controls, which points to a possible role of lipoxygenase pathway products in the pathophysiology of ocular allergic disorders. Lodoxamide 0.1%, DCG 2% and fluorometholone 0.1% were all effective in reducing LTB4 and LTC4 levels in VKC.

[Alomide eyedrops in the treatment of allergic conjunctivitis and keratoconjunctivitis]

New drug lodoxamine (alomide) opens new vistas in the treatment of allergic diseases of the eyes highly prevalent both in adults and children. This drug prevents release of mast cell mediators and delays eosinophil migration to conjunctival and corneal tissue, thus exerting a spectrum of antiallergic effects. Clinical studies carried out in 170 patients demonstrated a high efficacy of alomide in the treatment of subacute and chronic pollenosis conjunctivitis, spring keratoconjunctivitis, multiple and toxic allergic keratitis, and other allergic conjunctivities. Alomide can be used as a preventive drug in patients with allergies under high-risk conditions and in patients wearing contact lenses. It is effective in combined therapy of keratitis and keratouveitis. Alomide eye drops are well tolerated.

[Alomide, a preventive immunopharmaceutical agent, in the treatment of ocular atopy]

The author presents an account on initial experience with 0.1% lodoxamide in the treatment of atopy of the eyes. A positive effect was found in vernal catarrh. A favourable result was recorded in two sub-types of seasonal allergic conjunctivitis, mostly in the lower tarsal form with a follicular reaction in children and in purely limbal irritation in adults. The good effect in these two atypical forms of seasonal allergic conjunctivitis as a purely preventive immunopharmaceutical drug during the pollen season was remarkable.

Lodoxamide versus spaglumic acid: a comparative double-blind trial on patients suffering from seasonal allergic conjunctivitis induced by Parietaria pollen

In order to evaluate the efficacy and tolerability of lodoxamide in the treatment of allergic conjunctivitis, the authors conducted a double-blind trial with intrapatient comparison on 32 patients, using lodoxamide versus spaglumic acid in the course of two conjunctival provocation tests performed with specific allergens. The patients received one drop of lodoxamide in one eye and one drop of spaglumic acid in the other; 15 minutes later, 25 microliters of allergen extract at a pre-established concentration was instilled. After 10 minutes, the signs and symptoms of the allergic response were evaluated and recorded. Six hours later, the instillation of the allergen extract in both eyes was repeated following the same procedure, to establish the duration of the effect of the two drugs. The results, obtained by evaluating the main clinical signs and symptoms (itching, lacrimation, hyperaemia, palpebral oedema and chemosis), demonstrate with statistically significant differences that lodoxamide inhibits the conjunctival response to exposure to the allergen with greater efficacy than spaglumic acid, and for a longer duration. The two drugs provided similar and satisfactory tolerability. In view of these results, lodoxamide can definitely be considered and effective drug in the treatment of allergic conjunctivitis.

Efficacy of lodoxamide eye drops on mast cells and eosinophils after allergen challenge in allergic conjunctivitis

PURPOSE

The purpose of the study is to evaluate in a double-blind, randomized study the efficacy of lodoxamide tromethamine 0.1% versus placebo.

METHODS

Signs and symptoms, tear tryptase, and tear fluid cytology were evaluated in 20 asymptomatic subjects with allergic conjunctivitis. The study included three allergen challenges in skin test-positive patients. At the first visit, a threshold dose of allergen was established. At the second visit, a bilateral ocular challenge was performed without pretreatment. At the third visit, either lodoxamide or placebo eye drops were used for 1 week before ocular challenge.

RESULTS

Lodoxamide significantly reduced tryptase levels (P < 0.01), neutrophils (P < 0.04), and eosinophils (P < 0.01) in the tear fluid and significantly inhibited ocular itching (P < 0.02) when compared with that of placebo.

CONCLUSIONS

Lodoxamide is effective in reducing tryptase levels and the recruitment of inflammatory cells in the tear fluid after allergen challenge.

Effect of lodoxamide and disodium cromoglycate on tear eosinophil cationic protein in vernal keratoconjunctivitis

AIM

To validate the use of tear eosinophil cationic protein (ECP) as a marker for eosinophil activation, and its pharmacological modulation, in addition to evaluating the efficacy of lodoxamide and sodium cromoglycate in the treatment of vernal keratoconjunctivitis (VKC).

METHODS

Tears were collected from 30 patients affected by active mild to moderate VKC before and after therapy with disodium cromoglycate 4% (DSCG) (n = 15) or lodoxamide 0.1% (n = 15) for 10 days. Tear cytology and ECP measurement were performed, and ocular signs and symptoms evaluated.

RESULTS

While statistically significant changes did not occur after DSCG therapy, mean tear ECP increased from 343 (SD 363) micrograms/l to 571 (777) micrograms/l due to marked elevation in six eyes. The clinical score in DSCG eyes did not improve. After lodoxamide therapy, both clinical signs and symptoms, and tear ECP levels (560 (756) micrograms/l to 241 (376) micrograms/l) decreased significantly (p < 0.0001 and p < 0.01, respectively). Compared with DSCG treatment, lodoxamide was more effective in reducing signs and symptoms (p < 0.005). ECP levels were significantly correlated with signs, symptoms, corneal involvement, and number of eosinophils in tears (p < 0.0001).

CONCLUSIONS

In patients with VKC, lodoxamide significantly reduced ECP tear levels, and thus, eosinophil activation, and was more effective than DSCG in reducing clinical signs and symptoms.

Antiallergic activity of topical lodoxamide on in vivo and in vitro models

Lodoxamide is an antiallergic drug acting as a mast-cell stabilizer, which is effective in the treatment of allergic conjunctivitis. The study aimed to evaluate the effect of lodoxamide eye-drops on the inflammatory early-phase reaction (EPR) changes induced by allergen-specific conjunctival challenge (ASCC). This was a cross-over, double-blind, placebo-controlled, randomized study, including 10 outpatients suffering from allergic rhinoconjunctivitis due to Parietaria judaica. Patients received one drop of lodoxamide tromethamine 0.1% or placebo 30 min before each ASCC. Clinical evaluation and cytologic assessment were done at baseline and 30 min after each ASCC. Lodoxamide induced a reduction in total symptom score and hyperemia during the EPR (P < 0.05). Lacrimation, itching/burning, and eyelid swelling were only slightly (nonsignificantly) reduced. Lodoxamide induced a reduction in the total number of inflammatory cells and neutrophils during the EPR (P < 0.02). Eosinophil and lymphocyte number and ICAM-1 expression showed only a slight, not statistically significant decrease. Placebo did not affect the studied parameters. Lodoxamide reduced early clinical events and cellular changes after ASCC consistently with its activity as mast-cell stabilizer. Moreover, lodoxamide was able to downregulate in vitro ICAM-1 expression on the continuously cultured, differentiated conjunctival cell line WK. This was shown both in basal conditions (P < 0.05) and upon interferon-gamma stimulation (P < 0.03), although at high concentration.

Contact lens induced conjunctivitis: a model of human ocular inflammation

PURPOSE

To demonstrate the usefulness of contact lens induced conjunctivitis as a model of human ocular inflammation and to evaluate the effect of antiallergic eyedrops on this model.

METHODS

We recruited 40 subjects with contact lens induced conjunctivitis. Half were treated with ketorolac tromethamine (KT), and half with iodoxamide tromethamine (LT). Signs, symptoms, contact lens wearing time, and wearing time until discomfort developed were evaluated at baseline, day 7, and day 14.

RESULTS

The group receiving LT showed improvement of symptoms 7 days after beginning the study (P = 0.016), and both the LT and KT groups showed improvement from baseline on day 14 (P = 0.001 and P = 0.004, respectively). Signs improved for both the KT group (P = 0.011) and the LT group (P = 0.043) on day 7 and day 14 (P = 0.033 and P = 0.007, respectively). Mean contact lens wearing time improved on day 14 for the group treated with KT (P = 0.001).

CONCLUSIONS

Contact lens induced conjunctivitis appears to be a useful model of human ocular inflammation. Both antiallergics KT and LT improve contact lens tolerance in subjects with contact lens induced conjunctivitis. Two weeks of treatment may be required to demonstrate therapeutic benefits of antiallergic drops.

A critical look at ocular allergy drugs

Topical ocular allergy drugs are indicated for the treatment of allergic conjunctivitis after more conservative measures have been employed. Antihistamines, vasoconstrictors, nonsteroidal anti-inflammatory drugs, mast cell stabilizers and corticosteroids are available. Levocabastine and ketorolac tromethamine are new drugs for the treatment of allergic conjunctivitis. Lodoxamide is currently indicated only for the treatment of vernal keratoconjunctivitis, although treatment efficacy has been demonstrated in patients with giant papillary conjunctivitis and atopic keratoconjunctivitis. As a general rule, topical ocular allergy drugs are well tolerated by most patients except for transient stinging and burning on instillation. Ocular steroids should be reserved for severe cases and should be prescribed by an ophthalmologist, who can monitor the patient for possible ocular side effects.

Lodoxamide in vernal keratoconjunctivitis

Lodoxamide may be superior compared with cromolyn sodium for treatment of VKC. It is difficult, however, to conclusively determine the superiority of lodoxamide compared with cromolyn from the three studies reviewed in this article. Optimally, a triple-blind, randomized, placebo-controlled, multicenter trial involving the ophthalmic products cromolyn sodium 4%, lodoxamide 0.1%, and placebo (preferably NaCl 0.9%) with a treatment duration of at least 90 days and a similar sample size for each study group would lend the most credence to the determination of superiority of lodoxamide compared with cromolyn sodium for the treatment of VKC.

Effects of lodoxamide (LOD), disodium cromoglycate (DSCG) and N-acetyl-aspartyl-glutamate sodium salt (NAAGA) on ocular active anaphylaxis

LOD, DSCG and NAAGA eye-drops were evaluated on experimentally-induced ocular active anaphylaxis in guinea pigs. Twelve animals per group were sensitized with egg albumin i.p. and challenged on the surface of the eye 14 days later. Two days before challenge, animals were treated with LOD, DSCG or NAAGA 4 times a day. Permeability indexes were calculated after intracardiac injection of Evans Blue. No effect on ocular active anaphylaxis was found with LOD nor with DSCG. NAAGA was able to significantly reduce blood-eye permeability indexes.

Efficacy of lodoxamide 0.1% versus N-acetyl aspartyl glutamic acid 6% ophthalmic solutions in patients with vernal keratoconjunctivitis

In a double-masked, randomized and controlled clinical trial, the effectiveness and safety of lodoxamide 0.1% eye drops were compared with N-acetyl aspartyl glutamic acid 6% (NAAGA) drops in the treatment of 120 patients with vernal keratoconjunctivitis. There were 60 patients in each of the two study groups. The drugs were instilled 4 times daily for 60 days. Follow-up examinations were made on days 7, 30 and 60. Of the 120 patients, 98 (50 in lodoxamide and 48 in NAAGA groups) were still available for follow-up on day 7, 89 (45 in lodoxamide and 44 in NAAGA groups) on day 30 and 75 (38 in lodoxamide and 37 in NAAGA groups) on day 60. Lodoxamide was clinically more effective than NAAGA. Statistically significant trends toward improvement were noted in the lodoxamide group in resolving papillae on day 30, decreasing corneal staining on days 30 and 60, relieving photophobia on day 60, tearing on days 7, 30 and 60 and itching on days 30 and 60. Lodoxamide 0.1% was more effective in lowering the mean scores for corneal staining on days 30 and 60 (p < 0.05). The composite scores for clinical signs and symptoms calculated by averaging the mean scores for signs and symptoms showed clinically significant differences in favor of the lodoxamide group. More frequent follow-up visits might have resulted in better statistical correlations. Treatment-related adverse events were reported in both groups with similar frequency but none were permanent or serious.

Lodoxamide tromethamine treatment for superior limbic keratoconjunctivitis

PURPOSE

We studied the efficacy of topically applied lodoxamide tromethamine 0.1% in the treatment of superior limbic keratoconjunctivitis.

METHODS

Three patients with clinical findings of bilateral superior limbic keratoconjunctivitis. were treated with topical lodoxamide tromethamine four times daily in both eyes.

RESULTS

While the patients were taking lodoxamide tromethamine, symptoms and objective findings resolved.

CONCLUSIONS

Topically applied lodoxamide tromethamine 0.1% is useful in the treatment of superior limbic keratoconjunctivitis. There may be a role for mast cell stabilizers in the treatment of this disorder.

Lodoxamide treatment of allergic conjunctivitis

Lodoxamide is an antiallergic compound. The present study evaluated the efficacy on clinical and cytological parameters and safety of topical lodoxamide compared to placebo in the treatment of allergic conjunctivitis. The trial, designed as double-blind, randomized, placebo-controlled and parallel group treatment, was carried out in 30 patients, suffering from seasonal allergic conjunctivitis due to grass pollen, during the pollen season. Patients received lodoxamide tromethamine 0.1% eye drops or placebo eye drops, one drop in each eye t.i.d. for 4 weeks. The clinical and cytological evidence was investigated by clinicians on admission and after 4 weeks' treatment. At the end of the trial, only the lodoxamide-treated group showed a significant clinical improvement, associated with a reduction of inflammatory cells. No serious side effects were observed. The results show the clinical efficacy of lodoxamide in the treatment of pollen-induced allergic conjunctivitis. In addition, lodoxamide exerts its antiallergic activity by reducing inflammatory infiltrate (mainly eosinophils).

New therapeutic agents marketed in 1993

In 1993, the Food and Drug Administration (FDA) approved 25 new molecular entities (NMEs), 23 of which are for therapeutic use and two are diagnostic agents. Eleven of the NMEs for therapeutic use, as well a new biological agent intended for therapeutic use, were both approved and marketed in the United States in 1993. In addition, 11 other NMEs that the FDA approved before 1993 (most in late 1992) were marketed during the year. Thus, a total of 23 therapeutic agents reached the U.S. market for the first time in 1993, a considerably lower number than the 30 new therapeutic agents marketed in 1992 and the record number 31 new agents marketed in 1991. Many of the 13 therapeutic agents approved in 1993 but not marketed before the end of the year have become available in early 1994. Of the 23 new therapeutic agents first marketed in 1993, 22 are considered in this series. The one agent not reviewed is flosequinan, which was withdrawn from the market after being available only several months because of a concern about toxicity. This review considers the new agents' most important properties and, when possible, compares them with other available agents with similar properties. When additional information is needed, more comprehensive references and the product literature should be consulted.

Efficacy and safety of lodoxamide 0.1% vs cromolyn sodium 4% in patients with vernal keratoconjunctivitis

A multicenter, double-masked, parallel-group clinical study compared the efficacy and safety of lodoxamide 0.1% ophthalmic solution and cromolyn sodium 4% ophthalmic solution in 120 patients with vernal keratoconjunctivitis. On various follow-up visits, the clinical efficacy of lodoxamide 0.1% was statistically superior to cromolyn sodium 4% in alleviating four of the primary symptoms (itching, tearing, foreign-body sensation, and discomfort) and five of the primary signs (Trantas' dots, palpebral conjunctival changes, bulbar conjunctival hyperemia, erythema/swelling of the eyelids and periorbital tissues, and epithelial disease). At no time during the study was cromolyn sodium 4% statistically superior to lodoxamide 0.1% in demonstrating improvements in clinical signs and symptoms of vernal keratoconjunctivitis. The physician's clinical judgment of patients' response to treatment showed lodoxamide 0.1% effected a greater and earlier improvement than cromolyn sodium 4%. Both drugs were safe for topical ophthalmic use when used four times daily for up to 28 days.

Prevention of ischemia-reperfusion injury by the allergy drug lodoxamide tromethamine

Lodoxamide tromethamine, an orphan antiallergy drug, inhibits degranulation of mast cells that reside in the myocardium and inhibits xanthine oxidase located in myocytes and predominantly in the vascular endothelium. The hypothesis evaluated was that lodoxamide tromethamine would attenuate oxygen free radical damage. Isolated working rat hearts were perfused with Krebs-Henseleit buffer containing 0, 1, 10, 100, or 1,000 mumol/L lodoxamide tromethamine at 37 degrees and 24 degrees C with ischemic times of 22 and 93 minutes, respectively. These ischemic intervals yielded 50% survival and 50% return of function in untreated hearts. Lodoxamide treatment alone at the onset of reperfusion was also studied. Performance end points were aortic flow, pressure, and coronary flow. Biochemical analyses included serotonin collected from coronary effluent as a marker of mast cell degranulation, uric acid for xanthine oxidase inhibition, myocardial adenosine triphosphate, and carbonyl group concentrations. Performance data demonstrated that lodoxamide was beneficial in a log-linear dose response when given continuously at both temperatures. Percent of preischemic values for untreated and maximal responses at 1,000 mumol/L of lodoxamide were as follows: a mortality of 50% in nontreated hearts versus 0%; aortic flow, 47% to 94% (37 degrees C), 46% to 86% (24 degrees C); cardiac output, 60% to 98% (37 degrees C), 58% to 97% (24 degrees C); adenosine triphosphate, 59% to 90% (37 degrees C), 48% to 65% (24 degrees C). Serotonin was undetectable from any hearts. Uric acid concentrations and carbonyl group content did not change with increasing dose. Lodoxamide demonstrated no benefit when given only during reperfusion, suggesting injury occurred at times other than reperfusion.

Compliance in clinical trials of two nonbronchodilator, antiasthma medications

An electronic monitoring device was used to assess patient compliance during clinical trials of two new aerosolized nonbronchodilator, antiasthma drugs. Compliance was poor, but similar, in both trials. Patients took the study drug as instructed on a mean of 37.3% days (range 10% to 77%) in one trial and 37.4% days (range 0% to 63%) in the other. Both underuse and overuse were observed. Underuse was seen on a mean of 38.9% days (range 9% to 81%) and 46.0% (range 15% to 80%) respectively; overuse on a mean of 23.5% days (range 6% to 54%) and 16.6% days (range 0% to 41%). In some patients ten or more activations of the device were recorded at the same time. In six patients such multiple simultaneous activations were recorded on two or more separate days. These patients were among the most noncompliant in the study. Multiple simultaneous activations frequently followed underuse days or preceded followup visits, suggesting the possibility of duplicity. Overall compliance was such that valid conclusions about efficacy of the drugs could only have been drawn in six of 34 patients.

Action of tioxamast on various models of anaphylactic shock, hyperreactivity and bronchial inflammation in guinea-pigs

Tioxamast, an anti-allergic compound inhibiting the release and synthesis of certain mediators of allergy and having no major antagonist effect towards such mediators, was experimented on various models of anaphylactic shock, hyperreactivity and bronchial inflammation in guinea-pigs. Tioxamast does not reduce passive pulmonary anaphylactic shocks induced in anaesthetized or conscious guinea-pigs by i.v. challenge of antigen. Likewise, the compound has no effect on systemic hyperreactivity towards i.v. histamine induced in anaesthetized guinea-pigs after a passive anaphylactic shock caused by i.v. challenge of antigen. On the other hand, tioxamast inhibits passive pulmonary anaphylactic shock induced in guinea-pigs by antigen aerosol in conscious guinea-pigs. Likewise, tioxamast decreases hyperreactivity to inhalation of histamine or carbamylcholine obtained after an active or passive anaphylactic shock by aerosol in conscious guinea-pigs. The oxamate derivative attenuates the increase in number of eosinophils and mononuclear cells obtained in the bronchoalveolar lavage fluid 24 hr after an active anaphylactic shock induced by aerosol. The anti-allergic activity of tioxamast on the various models carried out in guinea-pigs thus appears when these models are induced by a challenge of antigen or mediator by inhalation.

Xanthine oxidase generation of toxic oxygen metabolites in acute uveitis

Lodoxamide, a xanthine oxidase inhibitor, has antiphlogistic effects in the treatment of acute uveitis. The role of xanthine oxidase generated free radicals is discussed.

Effects of ethyl N-N-benzyl-methyl-oxamate in Meriones unguiculatus infected with Echinococcus multilocularis metacestodes. Biochemical and ultrastructural observations

Ethyl N-N-benzyl-methyl-oxamate is a N-substituted derivative of the oxamic acid, well-known as inhibitor of the lactate dehydrogenase activity. The biochemical and ultrastructural effects of this drug in Echinococcus multilocularis metacestodes and the repercussions in the livers of receptive host, Meriones unguiculatus, were investigated. This compound decreased the specific activity of the lactate dehydrogenase in the metacestodes and the host liver by 81 and 86.8%, respectively. This N-methyl compound has shown an important repercussion on the lactate dehydrogenase activity due to its greater lipophilicity and thus allows a better penetration of the molecule. In the host liver, a fall of the alkaline and acid phosphatases activity was observed. The glucose and glycogen concentrations were also decreased. The ultrastructural study provided an alteration of the tegument of the metacestodes and damages of the muscular system. The parenchyma was disorganized. In conclusion, these biochemical and ultrastructural data obtained with ethyl-N-N-benzyl-methyl oxamate in E. multilocularis metacestodes show clearly the importance of the lactate dehydrogenase activity in the metacestodes.

Do anti-allergic drugs or anticholinergic drugs have a role in the treatment of asthma?

After the successful introduction of sodium cromoglycate (SCG) for the treatment of asthma, emphasis was placed on its apparent novel mechanism of action, the inhibition of inflammatory mediator release from mast cells. This opened the flood gates for numerous SCG-derivatives, many with oral efficacy and improved potency. The majority of these compounds were ineffective clinically, casting doubts on SCG's mechanism of action and questioning the importance of mast cells in asthma. However, information on the heterogeneity of mast cells has directed recent drug screening to new, more relevant models of asthma involving other inflammatory cells. Consequently, nedocromil sodium has emerged to perhaps lead a new generation of antiallergic drugs. Bronchodilator anticholinergic drugs have met with a resurgence of interest of late with the development of a number of quaternary ammonium homologues of atropine. While not as effective as beta-adrenoceptor agonists in asthma they are particularly effective in chronic obstructive pulmonary disease. Drugs with anticholinergic properties and associated beneficial effects are also under investigation.

Effects of lodoxamide tromethamine on paraplegia that occurs after infrarenal aortic occlusion in the rabbit

The antioxidant lodoxamide tromethamine was assessed for effects on experimental spinal cord ischemia in the rabbit. Lodoxamide (20 mg/kg/hr) or 0.9% sodium chloride was infused beginning 15 minutes before infrarenal aortic occlusion and continuing for 105 minutes. With an occlusion time of 20 minutes, eight of eight lodoxamide-treated animals and five of eight saline-treated animals regained function after reperfusion. However, by 48 hours after occlusion, seven of eight saline-treated animals were completely paralyzed, whereas only two of eight lodoxamide-treated animals were paralyzed. An ischemia time of 30 minutes exceeded the protective capacity of this treatment. These results suggest lodoxamide may be useful in alleviating ischemic damage to the spinal cord.