F. Balsano

Inflammatory changes in conjunctival scrapings after allergen provocation in humans

This study was performed to investigate the inflammatory changes occurring in the human conjunctiva at different time periods after allergen provocation. Twenty-three ryegrass-sensitive patients with allergic conjunctivitis (19 with hayfever and four with vernal conjunctivitis) were challenged by topical administration of ryegrass antigen to the eye. Allergen concentrations were increased in increments until an immediate ocular allergic reaction was elicited. Numbers of various inflammatory cells (neutrophils, eosinophils, lymphocytes, and monocytes) found in conjunctival scrapings were quantified and correlated with the clinical profile, total serum IgE, and serum IgE to Rye I antigen. Twenty minutes after some level of antigen topical challenge to the eye, all patients had ocular redness, tearing, and itching. Compared with findings in seven control subjects, significant inflammatory cells were found in the conjunctival scrapings of patients before challenge (p less than 0.05) and 20 minutes (p less than 0.001) and 6 hours (p less than 0.002) after effective challenge. Significant increases in neutrophils of patients occurred after 20 minutes (p less than 0.001), and in eosinophils at 6 hours (p less than 0.005), compared with values of control subjects. When each case was evaluated individually, nine of the 23 patients had highly evident inflammatory changes 6 hours after allergen provocation. The levels of total serum IgE and serum IgE to Rye I antigen of these nine patients did not differ significantly from the other patients in the study. Our data provide the first evidence in humans that significant inflammatory changes in conjunctival scrapings are present long after allergen exposure has ended.

Allergen dose response and late symptoms in a human model of ocular allergy

Eleven ryegrass-sensitive patients were challenged weekly for 4 weeks with incremental doses of ryegrass allergen applied topically to one eye; a buffer was applied to the other eye. A clinical examination and tear-fluid cytology were performed before challenge and at 20 minutes, 1 hour, and 6 hours after challenge. A significant clinical reaction and neutrophil accumulation in the tear film occurred at 20 minutes. At 1 hour, a clinical response and tear cytologic reaction were present only at higher antigen concentrations. Six hours after antigen challenge, only the highest allergen concentration (320,000 BU/ml) produced a clinical late-phase reaction (LPR) (p less than 0.01) and tear cytologic change (presence of eosinophils and lymphocytes). Five nonryegrass-sensitive control subjects were unresponsive to a similar challenge. These results indicate that a conjunctival response to allergen challenge is dose dependent, that is, the higher the dose, the more likely an LPR will occur and that an LPR correlates with significant numbers of inflammatory cells in the tear film.

Effect of picotamide on the clinical progression of peripheral vascular disease. A double-blind placebo-controlled study. The ADEP Group.

BackgroundPatients with peripheral vascular disease (PVD) undergo a clinical course that can be complicated by cardiovascular events occurring in several areas of the circulation. Methods and ResultsIn the present study we investigated the ability of picotamide, a substance that inhibits platelet thromboxane A2 (TxA2) synthase and antagonizes TxA2 receptors, to reduce cardiovascular complications in PVD patients. The study was double blind and placebo controlled. After a 1-month run-in period, 2,304 patients were randomly allocated to either placebo or picotamide (300 mg t.i.d.) and followed for 18 months. Major and minor events were analyzed. Results of an “intention-to-treat analysis” were that patients on picotamide suffered 45 major events (3.9%) and 77 minor events (6.7%), whereas those taking placebo suffered 52 major (4.5%) and 99 minor events (8.6%). There was borderline statistical difference between the two groups with respect to the sum of the major and minor events (risk reduction, 18.9o; p=0.056, log-rank test). Results of an “on-treatment” analysis were that patients on picotamide suffered 40 major (3.8%) and 66 minor events (6.3%), whereas those taking placebo suffered 45 major (4.2%) and 95 minor events (8.9%o). The sum of both major and minor events was 106 (10.1%) in the picotamide group and 140 (13.1%) in the placebo group. This difference was significant (risk reduction, 23%; p=0.029, log-rank test). ConclusionsThe results of this study indicate that picotamide reduces cardiovascular complications in PVD patients. The apparently low effect of this drug in reducing major events suggests that further studies be made with picotamide in PVD patients who are at high risk of cardiovascular complications so as to further assess its clinical efficacy.

Influence of reduced glutathione infusion on glucose metabolism in patients with non—insulin-dependent diabetes mellitus

To evaluate the relationship between oxidative stress and glucose metabolism, insulin sensitivity and intraerythrocytic reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio were measured in 10 non-insulin-dependent diabetes mellitus (NIDDM) patients and 10 healthy subjects before and after the intravenous administration of GSH. In particular, after baseline insulin sensitivity was assessed by a 2-hour euglycemic hyperinsulinemic clamp, either glutathione (1.35 g x m2 x min(-1)) or placebo (saline) were infused over a period of 1 hour. The same protocol was repeated at a 1-week interval, in cross-over, according to a randomized, single-blind design. In healthy subjects, baseline intraerythrocytic GSH/GSSG ratio (P < .0005) and total glucose uptake (P < .005) were significantly higher than in NIDDM patients. In the same subjects, GSH infusion significantly increased total glucose uptake (from 37.1 +/- 6.7 micromol kg(-1) x min(-1) to 39.5 +/- 7.7 micromol x kg(-1) x min(-1), P < .05), whereas saline infusion was completely ineffective. In addition, the mean intraerythrocytic GSH/GSSG ratio significantly increased after GSH infusion (from 21.0 +/- 0.9 to 24.7 +/- 1.3, P < .05). Similar findings were found in diabetic patients, in whom GSH infusion significantly increased both total glucose uptake (from 25.3 +/- 9.0 micromol x kg(-1) x min(-1) to 31.4 +/- 10.0 micromol x kg(-1) x min(-1), P < .001) and intraerythrocytic GSH/GSSG ratio (from 14.8 +/- 4.1 to 21.7 +/- 6.7, P < .01). Pooling diabetic patients and controls, significant correlations were found between intraerythrocytic GSH/GSSG ratio and total glucose uptake (r = .425, P < .05), as well as between increments of the same variables after GSH infusion (r = .518, P < .05). In conclusion, our data support the hypothesis that abnormal intracellular GSH redox status plays an important role in reducing insulin sensitivity in NIDDM patients. Accordingly, intravenous GSH infusion significantly increased both intraerythrocytic GSH/GSSG ratio and total glucose uptake in the same patients.

Bleeding time in patients with cirrhosis: relation with degree of liver failure and clotting abnormalities

Patients with cirrhosis suffer from a complex haemostatic disturbance, due to abnormalities in clotting and fibrinolytic system activation and in primary haemostasis. The latter is indicated by a prolongation of bleeding time, which is a reliable indicator of platelet function in vivo. To further assess the relationship between bleeding time, degree of liver failure and clotting abnormalities in patients with cirrhosis, bleeding time was investigated in a prospective study of 70 consecutive patients with cirrhosis diagnosed by liver-needle biopsy, of whom 19 belonged to Child-Pugh class A, 29 to B and 22 to C. Among patients with cirrhosis, 40% had an abnormal bleeding time (> 10 min), and 42% had a platelet count < 100,000/microliters. Patients with severe liver failure (class C) had a lower platelet count and a more prolonged bleeding time than patients in classes A and B. Bleeding time was significantly inversely correlated to platelet count, fibrinogen, prothrombin activity and packed cell volume, and directly correlated to serum bilirubin and D-dimer. However, in class C patients, only a significant inverse correlation between bleeding time and fibrinogen was observed. These findings indicate that in cirrhosis worsening of platelet function is closely related to the degree of liver failure. The inverse correlation between bleeding time and fibrinogen indicates that a low value of this clotting parameter may account in part for platelet dysfunction.

Free radical-mediated platelet activation by hemoglobin released from red blood cells

It is known that the rate of thrombus formation depends on interaction between platelets and erythrocytes, but the mechanism of this process has remained obscure. We here show that nanomolar levels of hemoglobin released from damaged red blood cells can induce platelet aggregation. The molecular mechanism is not receptor-based, but involves oxidation of oxyhemoglobin by platelet-derived hydrogen peroxide, with subsequent generation of a small unknown free radical species, detected by ESR spectroscopy. Methemoglobin and carbon monoxide-treated hemoglobin are unable to cause platelet activation or radical formation. The aggregation of platelets induced by hemoglobin is completely blocked by catalase or radical scavengers. These findings indicate a role for a novel extracellular free radical second messenger in the activation of platelets.

Dipyridamole inhibits lipid peroxidation and scavenges oxygen radicals

Dipyridamole incubatedin vitro in systems which peroxidize fatty acids inhibited arachidonic acid, gammalinolenic acid and linoleic acid peroxidation. In the xanthine-xanthine-oxidase system, which produces superoxide anion, dipyridamole inhibited the reduction of cytochrome-C in a dose-dependent fashion. In systems generating hydroxyl radicals, dipyridamole reduced deoxyribose degradation in a dose-dependent manner. The study suggests that dipyridamole inhibits lipid peroxidation, probably by scavening oxygen free radicals.

Tissue plasminogen activator inhibitor in patients with systemic lupus erythematosus and thrombosis

OBJECTIVE--To examine the relations among tissue plasminogen activator antigen, plasminogen activator inhibitor, the lupus anticoagulant, and anticardiolipin antibodies in patients with systemic lupus erythematosus. DESIGN--Prospective study of blood samples (a) from selected patients with systemic lupus erythematosus whose disease was and was not complicated by a history of thrombosis or recurrent abortions, or both, and (b) from a series of healthy controls with a similar age and sex distribution. SETTING--University based medical clinic. SUBJECTS--23 Patients with definite systemic lupus erythematosus (American Rheumatism Association criteria), of whom 11 (eight women) aged 26-51 had a history of thrombosis or recurrent abortions, or both, and 12 (10 women) aged 23-53 had no such history. 15 Healthy subjects (10 women) aged 25-58 served as controls. MAIN OUTCOME MEASURES--Tissue plasminogen activator concentrations, plasminogen activator inhibitor activities, detection of the lupus anticoagulant, and values of anticardiolipin antibodies in the two groups of patients and in the patients with a history of thrombosis or abortions compared with controls. Other measurements included concentrations of proteins that are known to change during the acute phase of systemic lupus erythematosus--namely, fibrinogen, C3 and C4, and C reactive protein. RESULTS--Patients with a history of thrombosis or abortions, or both, had significantly higher values of tissue plasminogen activator and plasminogen activator inhibitor than patients with no such history. A significant correlation between tissue plasminogen activator and plasminogen activator inhibitor (r = 0.80) was found only in the patients with a history of complications of their disease. The lupus anticoagulant was detected in six of the 11 patients with a history of thrombosis or abortions when tested by measuring the activated partial thromboplastin time but was found in all 11 patients when tested by measuring the diluted activated partial thromboplastin time. Nine of these 11 patients had raised values of anticardiolipin antibodies. The findings showed no relation to the activity of the disease. CONCLUSIONS--A significant correlation between tissue plasminogen activator concentrations and plasminogen activator inhibitor activities was found only in patients whose systemic lupus erythematosus was complicated by a history of thrombosis or recurrent abortions. The findings show that these patients have raised plasminogen activator inhibitor activities, and the frequent association between these raised activities and the presence of the lupus anticoagulant suggests that the two may be linked.

Conjunctival Provocation Test as a Model for the Study of Allergy and Inflammation in Humans

The clinical response after allergen challenge and immunologic mechanisms leading to tissue inflammation have been extensively studied in the skin, nose and lung of allergic subjects. The present paper reviews personal studies aimed at evaluating clinical, cellular and humoral events after administration of specific allergen to the eye. Specific conjunctival provocation tests performed in grass-sensitive patients caused persisting inflammatory changes in conjunctival scrapings and tear fluid with a significant accumulation of different inflammatory cells depending on the time of observation (neutrophils, 20 min; eosinophils, 6 h; neutrophils, eosinophils and lymphocytes, 12-24 h after provocation). Increasing the dose of allergen resulted in a dose-dependent increase in the number of inflammatory cells recruited. When high doses of allergen were used, the challenge not only induced late-phase histological changes, but also clinical symptoms 6-10 h after provocation. Several mediators of allergic inflammation, such as histamine, C3a des-Arg, leukotrienes B4 and C4, were also present and could be measured in tears after allergen challenge. Our studies represent the first evidence in humans that a late phase of allergic reaction occurs in the eye. They also suggest that the conjunctival provocation test may represent a model for the study of cells and mediators involved in the pathophysiology of allergic inflammation as well as of its pharmacologic modulation.

Nimodipine in the treatment of old age dementias

1. In a multicenter, placebo-controlled, double-blind clinical study in 178 elderly patients with cognitive decline, nimodipine, a calcium antagonist was found to be a therapeutically effective agent in the treatment of old age dementias. 2. Treatment with 90 mg of nimodipine administered orally in divided doses for 12 weeks was significantly superior to an inactive placebo on all outcome measures including the Wechsler Memory Scale, the Mini Mental State Examination, the Global Deterioration Scale, the Sandoz Clinical Assessment Geriatric Scale, the Plutchik Geriatric Rating Scale, the Severity of Illness and Global Improvement Scales of Clinical Global Impression, and the Hamilton Psychiatric Rating Scale for Depression. 3. Adverse effects with nimodipine were few and mild. The drug was equally well tolerated and equally effective in the two major dementias of old age, i.e., primary degenerative and multi-infarct. The number of abnormal laboratory test readings remained essentially unchanged from pre-treatment to post-treatment.