Integrated pharmacokinetics and pharmacometabolomics to reveal the synergistic mechanism of a multicomponent Chinese patent medicine, Mailuo Shutong pills against thromboangiitis obliterans

BACKGROUND

Mailuo Shutong Pills (MLST) have displayed pharmacological activity against thromboangiitis obliterans (TAO). However, the active ingredients and therapeutic mechanism of MLST against TAO remained to be further clarified.

PURPOSE

The aim of this study was to explore the active components of MLST and their synergistic mechanism against TAO by integrating pharmacokinetics (PK) and pharmacometabolomics (PM).

METHODS

TAO model rats were established by sodium laurate solution. Firstly, the efficacy of MLST was evaluated by gangrene score, blood flow velocity, and hematoxylin-eosin (H&E) staining. Secondly, PK research was conducted on bioavailable components to characterize their dynamic behaviors under TAO. Thirdly, multiple plasma and urine metabolic biomarkers for sodium laurate-induced TAO rats were found by untargeted metabolomics, and then variations in TAO-altered metabolites following MLST treatment were analyzed utilizing multivariate and bioinformatic analysis. Additionally, metabolic pathway analysis was performed using MetaboAnalyst. Finally, the dynamic link between absorbed MLST-compounds and TAO-associated endogenous metabolites was established by correlation analysis.

RESULTS

MLST significantly alleviated gangrene symptoms by improving the infiltration of inflammatory cells and blood supply in TAO rats. Significant differences in metabolic profiles were found in 17 differential metabolites in plasma and 24 in urine between Sham and TAO rats. The 10 bioavailable MLST-compounds, such as chlorogenic acid and paeoniflorin, showed positive or negative correlations with various TAO-altered metabolites related to glutamate metabolism, histidine metabolism, arachidonic acid metabolism and so on.

CONCLUSION

This study originally investigated the dynamic interaction between MLST and the biosystem, providing unique insight for disclosing the active components of MLST and their synergistic mechanisms against TAO, which also shed light on new therapeutic targets for TAO and treatment.

Identifying quality markers of Mailuoshutong pill against thromboangiitis obliterans based on chinmedomics strategy

BACKGROUND

Mailuoshutong pill (MLSTP) is a traditional Chinese medicine (TCM) for the treatment of Thromboangiitis obliterans (TAO, Buerger's disease) which is a segmental non-atherosclerotic inflammatory occlusive disorder. However, the mechanism and quality standards of MLSTP have not been sufficiently studied.

PURPOSE

This work aims to investigate the potential mechanisms and quality markers (Q-markers) of MLSTP treating TAO based on the chinmedomics strategy.

METHODS

The therapeutical effect of MLSTP on TAO rats was evaluated by changes in body weight and clinical score, regional blood flow velocity and perfused blood vessel distribution, hematoxylin-eosin (H&E) staining, serum metabolic profile. Moreover, both endogenous metabolites and exogenous components were simultaneously detected in serum based on ultra-high performance liquid chromatography coupled with a Q Exactive hybrid quadrupole-orbitrap high resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS), and multivariate analysis was applied to identify the biomarkers, as well as the dynamic changes of metabolites were observed to explore the mechanism of action of MLSTP. In addition, the pharmacodynamic material basis were identified by correlation analysis between biomarkers and absorbed constituents. Finally, the Q-markers of MLSTP were determined according to the screening principles of Q-marker and validated the measurability.

RESULTS

MLSTP treatment alleviated disease severity of TAO, reduced inflammatory infiltration, and ameliorated vascular function. 26 potential biomarkers associated with glutamate metabolism, linoleic acid metabolism, arachidonic acid metabolism and so on were identified. Besides, 27 prototypical components were identified in serum, 16 of which were highly correlated with efficacy and could serve as the pharmacodynamic material basis of MLSTP against TAO. In addition, 7 compounds, namely, sweroside, chlorogenic acid, calycosin-7-glucoside, formononetin, paeoniflorin, liquiritigenin and 3-butylidenephthalide, were considered as potential Q-markers of MLSTP. Ultimately, the measurability of the seven Q-markers was validated by rapid identifcation and quantifcation.

CONCLUSION

This study successfully clarified the therapeutic effect and Q-markers of MLSTP by chinmedomics strategy, which is of great significance for the establishment of quality standards. Furthermore, it provides a certain reference for the screening of Q-markers in TCM prescriptions.

Pharmacological treatment for Buerger's disease

BACKGROUND

Buerger's disease (thromboangiitis obliterans) is a non-atherosclerotic, segmental inflammatory pathology that most commonly affects the small and medium sized arteries, veins, and nerves in the upper and lower extremities. The aetiology is unknown, but involves hereditary susceptibility, tobacco exposure, immune and coagulation responses. In many cases, there is no possibility of revascularisation to improve the condition. Pharmacological treatment is an option for patients with severe complications, such as ischaemic ulcers or rest pain.This is an update of the review first published in 2016.

OBJECTIVES

To assess the effectiveness of any pharmacological agent (intravenous or oral) compared with placebo or any other pharmacological agent in patients with Buerger's disease.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, Cochrane Central Register of Controlled Trials, MEDLINE, Embase, CINAHL, AMED, the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials register to 15 October 2019. The review authors searched LILACS, ISRCTN, Australian New Zealand Clinical Trials Registry, EU Clinical Trials Register, clincialtrials.gov and the OpenGrey Database to 5 January 2020.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) involving pharmacological agents used in the treatment of Buerger's disease.

DATA COLLECTION AND ANALYSIS

Two review authors, independently assessed the studies, extracted data and performed data analysis.

MAIN RESULTS

No new studies were identified for this update. Five randomised controlled trials (total 602 participants) compared prostacyclin analogue with placebo, aspirin, or a prostaglandin analogue, and folic acid with placebo. No studies assessed other pharmacological agents such as cilostazol, clopidogrel and pentoxifylline or compared oral versus intravenous prostanoid. Compared with aspirin, intravenous prostacyclin analogue iloprost improved ulcer healing (risk ratio (RR) 2.65; 95% confidence interval (CI) 1.15 to 6.11; 98 participants; 1 study; moderate-certainty evidence), and helped to eradicate rest pain after 28 days (RR 2.28; 95% CI 1.48 to 3.52; 133 participants; 1 study; moderate-certainty evidence), although amputation rates were similar six months after treatment (RR 0.32; 95% CI 0.09 to 1.15; 95 participants; 1 study; moderate-certainty evidence). When comparing prostacyclin (iloprost and clinprost) with prostaglandin (alprostadil) analogues, ulcer healing was similar (RR 1.13; 95% CI 0.76 to 1.69; 89 participants; 2 studies; I² = 0%; very low-certainty evidence), as was the eradication of rest pain after 28 days (RR 1.57; 95% CI 0.72 to 3.44; 38 participants; 1 study; low-certainty evidence), while amputation rates were not measured. Compared with placebo, the effects of oral prostacyclin analogue iloprost were similar for: healing ischaemic ulcers (iloprost 200 mcg: RR 1.11; 95% CI 0.54 to 2.29; 133 participants; 1 study; moderate-certainty evidence, and iloprost 400 mcg: RR 0.90; 95% CI 0.42 to 1.93; 135 participants; 1 study; moderate-certainty evidence), eradication of rest pain after eight weeks (iloprost 200 mcg: RR 1.14; 95% CI 0.79 to 1.63; 207 participants; 1 study; moderate-certainty evidence, and iloprost 400 mcg: RR 1.11; 95% CI 0.77 to 1.59; 201 participants; 1 study; moderate-certainty evidence), and amputation rates after six months (iloprost 200 mcg: RR 0.54; 95% CI 0.19 to 1.56; 209 participants; 1 study, and iloprost 400 mcg: RR 0.42; 95% CI 0.13 to 1.31; 213 participants; 1 study). When comparing folic acid with placebo in patients with Buerger's disease and hyperhomocysteinaemia, pain scores were similar, there were no new cases of amputation in either group, and ulcer healing was not assessed (very low-certainty evidence). Treatment side effects such as headaches, flushing or nausea were not associated with treatment interruptions or more serious consequences. Outcomes such as amputation-free survival, walking distance or pain-free walking distance, and ankle brachial index were not assessed by any study. Overall, the certainty of the evidence was very low to moderate, with few studies, small numbers of participants, variation in severity of disease of participants between studies and missing information (for example regarding baseline tobacco exposure).

AUTHORS' CONCLUSIONS

Moderate-certainty evidence suggests that intravenous iloprost (prostacyclin analogue) is more effective than aspirin for eradicating rest pain and healing ischaemic ulcers in Buerger's disease, but oral iloprost is not more effective than placebo. Very low and low-certainty evidence suggests there is no clear difference between prostacyclin (iloprost and clinprost) and the prostaglandin analogue alprostadil for healing ulcers and relieving pain respectively in severe Buerger's disease. Very low-certainty evidence suggests there is no clear difference in pain scores and amputation rates between folic acid and placebo, in people with Buerger's disease and hyperhomocysteinaemia. Further well designed RCTs assessing the effectiveness of pharmacological agents (intravenous or oral) in people with Buerger's disease are needed.

A Non-smoking Woman with Anti-phospholipid Antibodies Proved to Have Thromboangiitis Obliterans

A 48-year-old woman with severe pain and numbness of her right leg and foot was admitted to our hospital. She had never smoked and had little exposure to passive smoking. Initially, polyarteritis nodosa with anti-phospholipid antibodies was considered. Combination therapy with methylprednisolone pulse therapy, intravenous cyclophosphamide pulse therapy, vasodilators, antiplatelet agents, and anticoagulants was not effective. Vasculopathy was progressive, and she presented with gangrene of the toes. She required amputation of her right leg. The pathological findings of the amputated leg revealed thromboangiitis obliterans (TAO). TAO should be considered even in non-smoking women. Non-response to immunosuppressant and anticoagulant therapies may be a clue to the diagnosis of TAO.

Protective effects and potential mechanism of salvianolic acid B on sodium laurate-induced thromboangiitis obliterans in rats

BACKGROUND

The root of Salvia miltiorrhiza f. alba (RSMA) (Lamiaceae) is used for the treatment of patients with thromboangiitis obliterans (TAO) in traditional Chinese medicine. Previously, a mixture of phenolic acids extracted from RSMA has shown significant protective effects on TAO rats.

PURPOSE

This study investigates the inhibitory effects of salvianolic acid B on TAO induced by sodium laurate injection in rats to explore the effective constituents of RSMA in TAO treatment.

METHODS

TAO rats were developed using injected sodium laurate. After treatment with ligustrazine hydrochloride (15 mg/kg) and various doses of salvianolic acid B (10, 20, 40 mg/kg) by tail intravenous injection, levels of thromboxane B₂ (TXB₂), 6-keto-prostaglandin F_1α (6-keto-PGF_1α) and endothelin-1 (ET-1) in plasma were determined using enzyme-linked immunosorbent assay. The right femoral arteries were studied by hematoxylin and eosin staining and immunohistochemical analysis to determine pathological changes and overexpression of tumor necrosis factor (TNF)-α and inducible nitric oxide synthase (iNOS) in the femoral artery walls of TAO rats.

RESULTS

Salvianolic acid B significantly decreased the expressions of TXB₂ and ET-1 and increased the expression of 6-keto-PGF_1α in plasma, and significantly inhibited the overexpression of TNF-α and iNOS in the femoral artery walls of TAO rats at medium and high doses.

CONCLUSION

Salvianolic acid B has a protective effect on TAO rats. The mechanism may involve inhibition of thrombosis and TAO-associated inflammatory responses, which may explain the success of RSMA treatment of TAO in humans in traditional Chinese medical practice. Hence, it may be a potential drug for TAO treatment in conventional medicine.

Photo Rounds: Painful blisters on fingertips and toes

Our patient had visited the emergency department for painful blisters on her fingertips and toes. A follow-up visit to our clinic unearthed the cause.

Could Buerger's disease cause nonarteritic anterior ischemic optic neuropathy?: a rare case report

We present an interesting case with nonarteritic anterior ischemic optic neuropathy (NAION) accompanied by Buerger's disease. A 43-year-old man was referred to our neuro-ophthalmology clinic with a complaint of visual deterioration in the left eye that started 5 days ago. He suffered from Buerger's disease, and he had acute pain in the right lower limb below the knee. His best corrected visual acuity was 10/10 in the right eye and 2/10 in the left eye by Snellen chart. There was a relative afferent pupil defect in the left eye. The right optic disc was normal on fundus examination, and blurring, hemorrhagic swelling was found at the left optic disc. Inferior altitudinal visual field defect was observed in the left eye. Neurological examination was normal. Computed tomography angiography scan revealed occlusion in the right posterior tibial artery. Brain imaging and laboratory tests such as blood analyses, genetic screening, coagulation, and lipid panels were unremarkable. NAION may occur in patients with Buerger's disease, but it is extremely rare. Therefore, clinicians should be aware of this rare association.

Efficacy of bosentan in patients with refractory thromboangiitis obliterans (Buerger disease): A case series and review of the literature

The cornerstone of therapy in thromboangiitis obliterans (TAO) is complete abstinence from tobacco. In addition to discontinuation of cigarette smoking, very few pharmacological and surgical options of controversial efficacy are available to date. New therapeutic options with greater efficacy are clearly needed to properly manage these patients.In this preliminary study, we assessed the effectiveness and safety of bosentan in a case series of 8 adults with TAO and severe ischemic ulceronecrotic lesions who were treated with bosentan after inadequate response to platelet inhibitors, vasodilators, and intravenous alprostadil. Additionally, we reviewed 18 well-documented patients with refractory TAO treated with bosentan, which was previously reported (PubMed 1965-2015). These 26 patients formed the basis of our present analysis. All were current smokers.The median duration of bosentan treatment (SD) was 4.5 ± 4 months (range 3-16). Eleven patients (42%) were unable to completely abstain from smoking during their follow-up. With bosentan treatment, no new ischemic lesions were observed in the target extremities. A complete therapeutic response was achieved in 80% of patients, whereas a partial response was observed in 12%. Two patients (8%) ultimately required amputation despite treatment.After discontinuation of bosentan, patients were followed for a median of 20 ± 14 months (range 3-60). Two patients whose trophic lesions had healed relapsed.When comparing patients who gave up smoking with those who were unable to completely abstain from smoking during follow-up, no significant differences were found in efficacy outcomes. Four patients (15%) developed adverse events, requiring bosentan discontinuation in 1 case.These preliminary data suggest that bosentan may be considered a therapeutic option for treatment of cases of severe TAO refractory to conventional treatment, and merit further evaluation in larger controlled, randomized clinical studies.

The Prostacyclin Analog, Treprostinil Sodium, Provides Symptom Relief in Severe Buerger’s Disease

Buerger’s disease (thromboangiitis obliterans or TAO) is a clinical syndrome characterized by the development of segmental thrombotic occlusions of the medium and small arteries. The primary treatment for Buerger’s disease is cessation of cigarette smoking. In patients whose disease progresses despite smoking cessation, therapeutic options are limited. Revascularization is rarely indicated and usually not successful because of the diffuse and distal distribution of the disease. Prostacyclin, or PGI2, and its analogs have been proposed as pharmacotherapy for Buerger’s disease and studied in Europe. The authors review the prostacyclin literature in the treatment of Buerger’s disease and present a case report of a patient with progressive Buerger’s disease and the use of treprostinil sodium (Remodulin®). This case report experience suggests that subcutaneous treprostinil therapy could be clinically useful in Buerger’s disease that does not improve with smoking cessation, particularly in the presence of critical limb ischemia where other therapeutic options have failed.

Pharmacological treatment for Buerger's disease

BACKGROUND

Buerger's disease (thromboangiitis obliterans) is a non-atherosclerotic, segmental inflammatory pathology that most commonly affects the small and medium sized arteries, veins, and nerves in the upper and lower extremities. The etiology is unknown, but involves hereditary susceptibility, tobacco exposure, immune and coagulation responses. In many cases, there is no possibility of revascularization to improve the condition. Pharmacological treatment is an option for patients with severe complications, such as ischaemic ulcers or rest pain.

OBJECTIVES

To assess the effectiveness of any pharmacological agent (intravenous or oral) compared with placebo or any other pharmacological agent in patients with Buerger's disease.

SEARCH METHODS

The Cochrane Vascular Trials Search Co-ordinator searched their Specialised Register (last searched in April 2015) and the Cochrane Register of Studies (Issue 3, 2015). The review authors searched trial registers and the European grey literature; screened reference lists of relevant studies, and contacted study authors and major pharmaceutical companies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) involving pharmacological agents used in the treatment of Buerger's disease.

DATA COLLECTION AND ANALYSIS

Two review authors, independently assessed the studies, extracted data and performed data analysis.

MAIN RESULTS

Five randomised controlled trials (total 602 participants) compared prostacyclin analogue with placebo, aspirin, or a prostaglandin analogue, and folic acid with placebo. No studies assessed other pharmacological agents such as cilostazol, clopidogrel and pentoxifylline or compared oral versus intravenous prostanoid.Compared with aspirin, intravenous prostacyclin analogue iloprost improved ulcer healing (risk ratio (RR) 2.65; 95% confidence interval (CI) 1.15 to 6.11; 98 participants; one study; moderate quality evidence), and helped to eradicate rest pain after 28 days (RR 2.28; 95% CI 1.48 to 3.52; 133 participants; one study; moderate quality evidence), although amputation rates were similar six months after treatment (RR 0.32; 95% CI 0.09 to 1.15; 95 participants; one study; moderate quality evidence). When comparing prostacyclin (iloprost and clinprost) with prostaglandin (alprostadil) analogues, ulcer healing was similar (RR 1.13; 95% CI 0.76 to 1.69; 89 participants; two studies; I² = 0%; very low quality evidence), as was the eradication of rest pain after 28 days (RR 1.57; 95% CI 0.72 to 3.44; 38 participants; one study; low quality evidence), while amputation rates were not measured. Compared with placebo, the effects of oral prostacyclin analogue iloprost were similar for: healing ischaemic ulcers (iloprost 200 mcg: RR 1.11; 95% CI 0.54 to 2.29; 133 participants; one study; moderate quality evidence, and iloprost 400 mcg: RR 0.90; 95% CI 0.42 to 1.93; 135 participants; one study; moderate quality evidence), eradication of rest pain after eight weeks (iloprost 200 mcg: RR 1.14; 95% CI 0.79 to 1.63; 207 participants; one study; moderate quality evidence, and iloprost 400 mcg: RR 1.11; 95% CI 0.77 to 1.59; 201 participants; one study; moderate quality evidence), and amputation rates after six months (iloprost 200 mcg: RR 0.54; 95% CI 0.19 to 1.56; 209 participants; one study, and iloprost 400 mcg: RR 0.42; 95% CI 0.13 to 1.31; 213 participants; one study). When comparing folic acid with placebo in patients with Buerger's disease and hyperhomocysteinaemia, pain scores were similar, there were no new cases of amputation in either group, and ulcer healing was not assessed (very low quality evidence).Treatment side effects such as headaches, flushing or nausea were not associated with treatment interruptions or more serious consequences. Outcomes such as amputation-free survival, walking distance or pain-free walking distance, and ankle brachial index were not assessed by any study.Overall, the quality of the evidence was very low to moderate, with few studies, small numbers of participants, variation in severity of disease of participants between studies and missing information regarding for example baseline tobacco exposure.

AUTHORS' CONCLUSIONS

Moderate quality evidence suggests that intravenous iloprost (prostacyclin analogue) is more effective than aspirin for eradicating rest pain and healing ischaemic ulcers in Buerger's disease, but oral iloprost is not more effective than placebo. Verylow and low quality evidence suggests there is no difference between prostacyclin (iloprost and clinprost) and the prostaglandin analogue alprostadil for healing ulcers and relieving pain respectively in severe Buerger's disease. Very-low quality evidence suggests there is no difference in pain scores and amputation rates between folic acid and placebo, in people with Buerger's disease and hyperhomocysteinaemia. High quality trials assessing the effectiveness of pharmacological agents (intravenous or oral) in people with Buerger's disease are needed.

Pharmacological treatment for Buerger's disease

BACKGROUND

Buerger's disease (thromboangiitis obliterans) is a non-atherosclerotic, segmental inflammatory pathology that most commonly affects the small and medium sized arteries, veins, and nerves in the upper and lower extremities. The etiology is unknown, but involves hereditary susceptibility, tobacco exposure, immune and coagulation responses. In many cases, there is no possibility of revascularization to improve the condition. Pharmacological treatment is an option for patients with severe complications, such as ischaemic ulcers or rest pain.

OBJECTIVES

To assess the effectiveness of any pharmacological agent (intravenous or oral) compared with placebo or any other pharmacological agent in patients with Buerger's disease.

SEARCH METHODS

The Cochrane Vascular Trials Search Co-ordinator searched their Specialised Register (last searched in April 2015) and the Cochrane Register of Studies (Issue 3, 2015). The review authors searched trial registers and the European grey literature; screened reference lists of relevant studies, and contacted study authors and major pharmaceutical companies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) involving pharmacological agents used in the treatment of Buerger's disease.

DATA COLLECTION AND ANALYSIS

Two review authors, independently assessed the studies, extracted data and performed data analysis.

MAIN RESULTS

Five randomised controlled trials (total 602 participants) compared prostacyclin analogue with placebo, aspirin, or a prostaglandin analogue, and folic acid with placebo. No studies assessed other pharmacological agents such as cilostazol, clopidogrel and pentoxifylline or compared oral versus intravenous prostanoid.Compared with aspirin, intravenous prostacyclin analogue iloprost improved ulcer healing (risk ratio (RR) 2.65; 95% confidence interval (CI) 1.15 to 6.11; 98 participants; one study; moderate quality evidence), and helped to eradicate rest pain after 28 days (RR 2.28; 95% CI 1.48 to 3.52; 133 participants; one study; moderate quality evidence), although amputation rates were similar six months after treatment (RR 0.32; 95% CI 0.09 to 1.15; 95 participants; one study; moderate quality evidence). When comparing prostacyclin (iloprost and clinprost) with prostaglandin (alprostadil) analogues, ulcer healing was similar (RR 1.13; 95% CI 0.76 to 1.69; 89 participants; two studies; I² = 0%; very low quality evidence), as was the eradication of rest pain after 28 days (RR 1.57; 95% CI 0.72 to 3.44; 38 participants; one study; low quality evidence), while amputation rates were not measured. Compared with placebo, the effects of oral prostacyclin analogue iloprost were similar for: healing ischaemic ulcers (iloprost 200 mcg: RR 1.11; 95% CI 0.54 to 2.29; 133 participants; one study; moderate quality evidence, and iloprost 400 mcg: RR 0.90; 95% CI 0.42 to 1.93; 135 participants; one study; moderate quality evidence), eradication of rest pain after eight weeks (iloprost 200 mcg: RR 1.14; 95% CI 0.79 to 1.63; 207 participants; one study; moderate quality evidence, and iloprost 400 mcg: RR 1.11; 95% CI 0.77 to 1.59; 201 participants; one study; moderate quality evidence), and amputation rates after six months (iloprost 200 mcg: RR 0.54; 95% CI 0.19 to 1.56; 209 participants; one study, and iloprost 400 mcg: RR 0.42; 95% CI 0.13 to 1.31; 213 participants; one study). When comparing folic acid with placebo in patients with Buerger's disease and hyperhomocysteinaemia, pain scores were similar, there were no new cases of amputation in either group, and ulcer healing was not assessed (very low quality evidence).Treatment side effects such as headaches, flushing or nausea were not associated with treatment interruptions or more serious consequences. Outcomes such as amputation-free survival, walking distance or pain-free walking distance, and ankle brachial index were not assessed by any study.Overall, the quality of the evidence was very low to moderate, with few studies, small numbers of participants, variation in severity of disease of participants between studies and missing information regarding for example baseline tobacco exposure.

AUTHORS' CONCLUSIONS

Moderate quality evidence suggests that intravenous iloprost (prostacyclin analogue) is more effective than aspirin for eradicating rest pain and healing ischaemic ulcers in Buerger's disease, but oral iloprost is not more effective than placebo. Verylow and low quality evidence suggests there is no difference between prostacyclin (iloprost and clinprost) and the prostaglandin analogue alprostadil for healing ulcers and relieving pain respectively in severe Buerger's disease. Very-low quality evidence suggests there is no difference in pain scores and amputation rates between folic acid and placebo, in people with Buerger's disease and hyperhomocysteinaemia. High quality trials assessing the effectiveness of pharmacological agents (intravenous or oral) in people with Buerger's disease are needed.

Effect of Ocimum basilicum L. on cyclo-oxygenase isoforms and prostaglandins involved in thrombosis

ETHNOPHARMACOLOGICAL RELEVANCE

Ocimum basilicum L. (OBL) is a plant used in traditional Uyghur medicine for the treatment and prevention of cardiovascular disease. In previous studies we had found an antihypertensive and antithrombotic effect suggestive of an effect on prostaglandins, which we attempt to document here.

MATERIALS AND METHODS

6-keto-PGF1α, the metabolite of prostacyclin, and PGE2 were measured in the supernatant of human umbilical vein endothelial cells (HUVEC) and basal or LPS-stimulated mouse coeliac macrophage cultures exposed to OBL ethanol (OBL-E) extracts and petroleum ether, chloroform, ethylacetate and butanol (PE, C, EA, B) fractions. In addition, 6-keto-PGF1α and thromboxane B2 (TXB2) were measured in a rat model of thromboangiitis obliterans exposed or not to OBL.

RESULTS

Short-term exposure to OBL-E dose-dependently increased 6-keto-PGF1α from HUVEC, and long-term (24h) exposure decreased it. OBL-C and OBL-B increased 6-keto-PGF1α, whereas the other fractions tended to decrease it after 24h exposure. The extract and all fractions decreased basal and stimulated PGE2 production, but only OBL-EA and OBL-B reduced PGE2 in stimulated cultures to concentrations below the unstimulated values (P<0.05). In vivo OBL increased 6-keto-PGF1α and decreased TXB2.

CONCLUSION

OBL and its extracts increased 6-keto-PGF1α and reduced PGE2 and TXB2 production in a dose and time-related manner. This could indicate simultaneous inhibition of COX-2 and stimulation of endothelial COX-1. The butanol fraction seemed most promising in this respect.

[Efficacy of intravenous iloprost (Ilomedin®) in salvage of the only extremity in a patient with thrombangiitis obliterans]

Buerger s disease, or thromboangiitis obliterans, is a severe invalidating systemic vascular disease. The present article deals with a clinical case report concerning treatment of a patient suffering from thromboangiitis obliterans with three limbs amputated (on the background of therapy with alprostadil, Karavanov s mixture, rheopolyglukin, pentoxyphyllin). The course intravenous administration of the stable analogue of prostacyclin - iloprost (IlomedinR) made it possible to save the only extremity.

Effectiveness of bosentan in the treatment of ischemic lesions in a case of thromboangiitis obliterans (Buerger disease): a case report

Buerger disease or thromboangiitis obliterans (TAO) is a thrombotic occlusive, non-atherosclerotic segmental inflammatory disease that affects the small and medium-sized arteries and veins in the extremities of the limbs, frequently requiring amputation. Cessation of tobacco use is the only known effective treatment, though preliminary results from the use of pharmacological therapy implicated in pathogenesis of TAO have demonstrated noticeable clinical improvement of patients. We report the case of a 35-year-old woman with active TAO, refractory to smoking cessation and conventional therapy, who exhibited a favorable clinical response to treatment with bosentan, an oral dual endothelin receptor antagonist, administered on a compassionate-use basis. Six months after starting bosentan therapy, the pain and trophic lesions in the patient's toes had completely disappeared. Bosentan was well tolerated, without any observed adverse reaction. The findings of this case report suggest that bosentan may be considered a therapeutic option for patients with active disease, despite quitting smoking, or for those who fail in absolute abstention from smoking.

[Systemic vasculitis: study of 27 cases in Senegal]

Studies on vasculitis in black Africa are rare. The purpose of this report is to describe a retrospective study of systemic vasculitis managed in the internal medicine, ORL and cardiolology departments of the Aristide le Dantec University Hospital in Dakar, Senegal from 1995 to 2007. A series of 27 cases involving 7 men and 20 women with a mean age of 49 years was compiled. Primary vasculitis included Horton disease in 3 cases, Wegener disease in 2, Takayasu disease in 1, and Buerger disease in 1. Secondary vasculitis included mixed cryoglobulinemia with Gougerot Sjögren syndrome in 7 cases, primary Goujeröt syndrome in 4, rheumatoid arthritis in 3, nodosa periarteritis with hepatitis B in 2, SHARP syndrome in 1, and polymyositis in 1. The remaining two cases involved abdominal periaortitis including one associated with retrosperitoneal fibrosis and tuberculosis and the other with spondylarthropathy. Corticotherapy in combination with anticoagulants, immunosuppressive therapy, and surgery, when necessary, allowed effective management in 24 cases. The findings of this study show that systemic vasculitis can have numerous etiologies and indicate that secondary forms are the most common. Appropriate care modalities are needed to prevent severe outcome in Senegalese hospitals.

[Effect of Mailuoning injectable powder on experimental vascular occlusion angeitides in rats]

OBJECTIVE

To investigate the effect of Mailuoning injectable powder on experimental vascular occlusion angeitides in rats.

METHODS

Rats were injected laurostearic acid into arteria cruralis to induce the model of experimental vascular occlusion angeitides, then we observed the changes of objective sign of rats, and analysed throm ranking through pathological section under electro-microscope.

RESULTS

Mailuoning injectable powder could decrease the quantity of throm in blood vessel, and improve hemorrheoiogy.

CONCLUSION

The results show that Mailuoning injectable powder has obvious therapeutical effect on experimental vascular occlusion angeitides in rats, and its mechanism may be related to the anti-throm in blood vessel and improving hemorrheology.

Therapeutic potential of atrial natriuretic peptide administration on peripheral arterial diseases

Peripheral arterial diseases are caused by arterial sclerosis and impaired collateral vessel formation, which are exacerbated by diabetes, often leading to leg amputation. We have reported that an activation of the natriuretic peptides/cGMP/cGMP-dependent protein kinase pathway accelerated vascular regeneration and blood flow recovery in murine legs, for which ischemia had been induced by a femoral arterial ligation as a model for peripheral arterial diseases. In this study, ip injection of carperitide, a human recombinant atrial natriuretic peptide, accelerated blood flow recovery with increasing capillary density in ischemic legs not only in nondiabetic mice but also in mice kept upon streptozotocin-induced hyperglycemia for 16 wk, which significantly impaired the blood flow recovery compared with nondiabetic mice. Based on these findings, we tried to apply the administration of carperitide to the treatment of peripheral arterial diseases. The study group comprised a continuous series of 13 patients with peripheral arterial diseases (Fontaine's classification I, one; II, five; III, two; and IV, five), for whom conventional therapies had not accomplished appreciable results. Carperitide was administrated continuously and intravenously for 2 wk to Fontaine's class I-III patients and for 4 weeks to class IV patients. The dose was gradually increased to the maximum, with the patient's systolic blood pressure being kept above 100 mm Hg. Carperitide administration improved the ankle-brachial pressure index, intermittent claudication, rest pain, and ulcers. In conclusion, this study showed a therapeutic potential of carperitide to treat peripheral arterial diseases refractory to conventional therapies.

Limaprost

Limaprost, an alprostadil (prostaglandin E1) analogue, is a vasodilator that increases blood flow and inhibits platelet aggregation. The efficacy of oral limaprost was evaluated in adult Japanese patients in three randomised, double-blind, 6-week trials. One study included patients with thromboangiitis obliterans and two trials included patients with lumbar spinal canal stenosis. Limaprost was generally well tolerated and serious adverse events were uncommon. THROMBOANGIITIS OBLITERANS: In a randomised, double-blind trial in Japanese patients primarily with thromboangiitis obliterans (n=136), there was no significant difference between patients receiving limaprost 30 microg/day and those receiving oral ticlopidine 500 microg/day in the improvement of ischaemic symptoms. LUMBAR SPINAL CANAL STENOSIS: Limaprost 15 microg/day was superior to limaprost 3 microg/day for overall drug usefulness and overall improvement from baseline to study end in a phase III trial in 146 patients with lumbar spinal canal stenosis. Assessment of overall improvement considered various objective symptoms (e.g. muscle strength, walking ability) and subjective symptoms (e.g. pain or numbness in extremities), while overall usefulness also considered safety issues. The efficacy of limaprost 15 microg/day was not significantly different from that of 30 microg/day, but tended to be better than that of 6 microg/day in a phase II trial in patients with lumbar spinal canal stenosis and normal straight leg raise test results. The optimal dosage of limaprost for this indication was therefore deemed to be 15 microg/day.

Pregnancy complicated with Buerger's disease

Buerger's disease is an inflammatory occlusive vascular disorder involving small- and medium-sized arteries in the distal extremities and is usually complicated with thrombophlebitis. Since Buerger's disease develops most frequently in men who smoke, pregnancy complicated with this disease is extremely rare. Only three pregnancies have been reported previously. All cases indicate that Buerger's disease worsens during pregnancy. However, anti-coagulant therapy appeared to be effective in this case. Accordingly, careful observation is mandatory in pregnancies complicated with Buerger's disease.

A randomized trial of intravenous iloprost (a stable prostacyclin analogue) versus lumbar sympathectomy in the management of Buerger's disease

AIM

The aim of this study was to compare the effects of iloprost and lumbar sympathectomy (LS) in the treatment of Buerger's disease.

METHODS

Two hundred patients with rest pain and/or ischemic ulcers were randomized to undergo LS or 28-day intravenous treatment of iloprost. The primary endpoint was complete healing without pain or major amputation at 4 and 24 weeks. The secondary endpoints were analgesic requirement, reduction in the ulcer size, 50% reduction of the ulcer, and shift in the modified SVS/ISCVS clinical status grading scale.

RESULTS

The comparison was carried out in 162 patients (iloprost: n=84; LS: n=78). Complete healing rate was 61.9% in the iloprost group, but 41% in the LS group at the 4th week (P=0.012); respective values for the 24th week were 85.3%, 52.3%, P<0.001. Analgesic requirement was lower in the iloprost group at the 4th and 24th weeks (P=0.01, and P=0.098, respectively). The size of the ulcers decreased more in the iloprost group than the LS group (P=0.044 and P=0.035 at 4th and 24th weeks); 50% reduction in the ulcer size in the iloprost group was greater than in the LS group (P=0.001 and P=0.009 at 4th and 24th weeks). SVS/ISCVS grading scale demonstrated a better clinical benefit in patients treated with iloprost (P<0.001 at 4th week, and P<0.001 and at 24th week).

CONCLUSIONS

The results of this independent study indicate that using iloprost relieves ischemic symptoms better than LS. In the era of stable prostacyclin analogues, there is no reliable evidence to support the use of LS in Buerger's disease.

Intravenous infusion for the treatment of diabetic and ischaemic non-healing pedal ulcers

Diabetic and ischaemic non-healing pedal ulcers have a tendency for chronicity and increased chances of infection, which may threaten the viability of the foot. Systemic administration of therapeutic agents may be insufficient in these cases. We have assessed the role of retrograde venous perfusion (RVP) for the treatment of nine diabetic and 10 ischaemic non-healing pedal ulcers. Agents used were soda bicarbonate, heparin, lignocaine, gentamicin and pentoxiphylline. Five of nine diabetic non-healing ulcers showed complete healing and the remaining four improved. The complete recovery in the cases of diabetic ulcer occurred in 10-24 days (mean 16 days), while ischaemic ulcers took 10-14 days for complete recovery (mean 13.6 days). There was a reduction of rest pain in all 10 patients with ischaemic disease; five patients showed complete healing of ulcers, and the other five improved significantly. In two patients, pre-gangrene changes were reversed. RVP is a useful adjunct to conservative or surgical treatment of non-healing pedal ulcers. Its main impact was in improving ischaemia and promoting healing.

Use of duplex ultrasonography in the treatment of thromboangiitis obliterans with iloprost

We present a 34-year-old patient with digital necrosis due to thromboangiitis obliterans. He was successfully treated with iloprost, a prostaglandin analogue. Duplex ultrasonography was performed during the perfusion of iloprost to optimize the doses and the treatment duration. A complete revascularization was observed after 10 days. Iloprost perfusions were stopped, and a slow regression of the necroses was observed in the subsequent days. With the use of duplex ultrasonography, unnecessary high doses of iloprost and long periods of treatment can be avoided reducing side effects and treatment costs.

[Diagnostic image (195). A man with blue finger tips]

A 42-year-old man had ischaemia of three fingers of his left hand caused by thromboangiitis obliterans (Buerger's disease).

[A role of endothelin 1 in the pathogenesis of thromboangiitis obliterans (initital news)]

BACKGROUND

[corrected] Etiology and pathogenesis of thromboangiitis obliterans, an uncommon disease, but connected with high risk of leg amputation, is still unknown. Genetic predisposition and inconvenient factors of environment, especially nicotine, could initiate an immunological process, which evokes endothelial dysfunction. In histological preparation inflammation and thrombus are observed. Endo-thelin-1 could affect these processes. It is a strong vasa-constrictor and has a wide spectrum of biological activity, often opposed to effect of prostacycline analogs. The aim of study was a role of endothelin-1, antielastin antibodies and selectin P, L, E in the pathogenesis Buerger's disease and influence of alprostadil on these parameters.

MATERIAL AND METHODS

We examined 10 patients with Buerger disease in the active phase, which were divided in two subgroups. Four persons with necrosis of toes were in the first subgroup, and six patients with rest pain but without trophic changes in the second subgroup. 13 healthy persons composed the control group. Index of antielastin antibodies, concentration of endotehlin-1, selectin P, L and E were measured in venous and arterial serum. These parameters by patients were determined twice: before and after 10-days treatment with alprostadil 20-40 microg per day. Concentration of endothelin-1, selectins and index antielastin antibodies were measured by enzyme-linked immuno-sorbent assay.

RESULTS

We observe increase in endothelin-1 concentration by persons with necrosis of toes compared to patients without these changes (p=0.024) and to control (p=0.022). In the subgroup I index of antielastin antibodies IgA was higher than in control group (p=0.020). After alprostadil treatment endothelin-1 concentration, antielastin antibodies index was not statistically significant compared to results before treatment or control group. We observed correlation between concentration of endo-tehlin-1 before treatment and index of antielastin antibodies IgG (p=0.0475). We observed significant diffrance of concentration of selectin P, L and E compared to control (p=0.038). Especially we noticed higher concentration of selectin P (p=0.001) than in control group. The after treatment reduction of concentration was only for selectin L statistically significant (p=0.038).

CONCLUSION

1. Plasma endothelin-1 level play a role in the exacerbation of clinical symtpoms of thromboangiitis obliterans. 2. Endothelial injury is connected with increase in concentration of selectin P in patient's serum. 3. Alprostadil didn't influence on concentration of endothelin-1 in these patients.

[Pulse-therapy with glucocorticoids and cyclophosphamide in the treatment of thromboangiitis obliterans]

Effectiveness of glucocorticoid and cyclophosphamide pulse-therapy was studied in patients with thrombangitis abliterans (TA). We examined 28 males. All of them were treated with antiplatelet agents and vasodilators in standard doses. In addition, 16 patients received a standard three-day scheme of a glucocorticoid and cyclophosphamide pulse-therapy. The examination of the patients was carried out before the treatment and in a month. Estimation of clinical activity was made according to the BVAS index, serum levels of C-reactive protein (CRP) and von Willebrand factor antigen (VWF-Ag), ESR. Before the start of the treatment there were no significant differences in the values of BVAS, ESR and CRP between the groups. In a month, BVAS index, concentrations, the rate of high serum levels of CRP and frequency of amputations were significantly reduced in patients treated with pulse-therapy. So, this pulse-therapy has a considerable anti-inflammatory effect and decreases frequency of amputations in thrombangiitis obliterans.

[New aspects of prostaglandin E1 therapeutic influence in thrombo-angiitis obliterans]

Prostaglandin E1 because of its unique protective and repaired endothelial action is used in the treatment of many diseases. The aim of the study was the investigation of prostaglandin E1 influence on some adhesive molecules profile in the patients with thrombangitis obliterans. 21 patients, aged 31-49 years (mean 40.3 +/- 5.3), with thrombangitis obliterans were observed. The control group consisted of 22 healthy patients, aged 18-50 years (mean 34.6 +/- 12.25 years). In both groups as well the number of circulated endothelial cells and selectin L, P, E and vWF factor concentration were measured. In patients suffered from thrombangitis obliterans these parameters were measured before and after 21 days intraarterial 10 mg PGE1 (Alprostadil) infusion. No PGE1 influence on selectin E concentration was observed, the mean values as well before as after the treatment were equal to 66.56 +/- 8.92 ng/ml. The decrease in selectin P concentration was observed but the difference was not statistically significant. The statistically significant reduction was observed in selectin L (decrease from 799.88 +/- 104.79 ng/ml to 764.83 +/- 116.04 ng/ml) and vWF concentration (decrease from 195.04% +/- 26.2% to 187.69% +/- 22.83%). The final PGE1 therapeutic result was the circulating endothelial cells decrease (from 2.47 +/- 1.01 before to 2.36 +/- 0.97 cells/ml after treatment). Intraarterial PGE1 infusion in patients with thrombangitis obliterans results in significant selectin L, vWF factor concentration decrease less; this decrease is less marked in selectin P concentration. As the inhibition of the adhesive molecules activation effect the number of exfoliated circulated endothelial cells decrease is observed.

Enhanced platelet force development despite drug-induced inhibition of platelet aggregation in patients with thromboangiitis obliterans--two case reports

Thromboangiitis obliterans (TAO) is a nonatherosclerotic, nonnecrotizing, nonspecific, segmental inflammatory obliterative vasculitis, characterized by decreased flow to the distal extremities and increased risk of amputation. While smoking cessation is viewed as critical to successful treatment, various therapeutic options have been employed. While many treatment regimens seek to diminish platelet function, there are relatively few studies of platelet function in this disease entity and even fewer that have offered evidence of increased platelet activity. The authors report here 2 cases of TAO in which evaluations for hypercoagulable states and of platelet function were performed. Platelet contractile force (PCF) was found to be 82% higher than a normal control in 1 TAO patient and 340% higher than normal in the second patient. This was true despite the fact that platelet aggregations confirmed suppression of aggregation by antiplatelet medications. Elevated PCF has been seen in a variety of conditions, such as coronary artery disease and diabetes mellitus, in which endothelial function is abnormal. Whether high PCF values play a role in the pathogenesis of these diseases or simply serve as markers of enhanced platelet function and/or endothelial dysfunction awaits additional evaluations.

[Bilateral hydronephrosis associated with Buerger's disease: a case report]

A 28-year-old man visited our hospital complaining of the ulcerous lower extremity. An angiography showed the stenosis of the dorsal digital artery. The clinical diagnosis was Buerger's disease. The administration of prostaglandin I2 (PG I2) and antithrombotic drug were done. The ulcerous lower extremity improved. But a computerized tomographic scan of the abdomen showed the bilateral hydronephrosis incidentally. A retrograde pyelography (RP) revealed the bilateral ureteral strictures. We suspected the etiology was the retroperitoneal fibrosis associated with Buerger's disease.

[A patient with thromboangiitis obliterans]

BACKGROUND

Thromboangiitis obliterans (Buerger's disease) is characterised by inflammatory thrombi in small and middle-sized arteries and in the veins. As opposed to arteriosclerosis, the vessel wall remains normal. Diagnostic criteria are the presence of distal ischaemia in the extremities, documented by noninvasive vascular testing; exclusion of autoimmune diseases, hypercoagulable states, and diabetes mellitus, age less than 45 years and cigarette smoking.

MATERIAL AND METHODS

The article is based on a case history and review of the literature.

RESULTS AND INTERPRETATION

A 31-year-old man was in 1953 diagnosed with thromboangiitis obliterans. Lumbar sympathectomy on the left side in 1953 and on the right side in 1971 had excellent symptomatic effect. The patient has been treated with anticoagulants for 48 years. Amputation of the left 2nd toe was performed in 1971. At age 80, he is without further cardiovascular events and takes regular physical exercise. Over the last fifty years, the incidence of thromboangiitis obliterans has been drastically reduced. The reason for this is unknown. The only proven treatment is complete discontinuation of tobacco. The effect of sympathectomy and long-term anticoagulation has not been proven.

Buerger's disease and anticardiolipin antibodies: a worse prognosis?

The case of a 26-year-old male chronic smoker is reported, who had thrombotic incidences on three occasions in both upper and lower limbs over a 10-month period. Laboratory examinations, including hematologic studies and creatinine, cholesterol, and glucose levels, were normal. However, IgG and IgM anticardiolipin antibodies were detected. Duplex ultrasonography confirmed deep venous thrombosis in both lower limbs (two occurrences) and computer tomography depicted an inferior cava vein thrombosis. The patient fulfilled all of Shionoya's criteria for Buerger's disease, thus suggesting an association between anticardiolipin antibodies and this disease.

Treatment of patients with thromboangiitis obliterans with cyclophosphamide

This report describes a small, nonrandomized trial of cyclophosphamide in the treatment of patients with advanced thromboangiitis obliterans (TAO) with modest results. The rationale of the treatment was based on the immunopathogenesis of the disease, ie, autoimmune vasculitis of peripheral arteries. Twelve male patient volunteers with TAO were included for the trial. Diagnosis was based on the history of chronic smoking or tobacco chewing, clinical features of ischemia of peripheral vessels, radioarteriography showing arterial block, and characteristic histopathologic changes of affected arteries. Cyclophosphamide (400 mg) was given intravenously daily to the patients for 7 days followed by daily oral administration of 100 mg cyclophosphamide for another 7 weeks. Clinical conditions of the patients started to improve during the third week of the treatment and maximum benefit was noticed at the end of the treatment. There was significant decrease of intermittent claudication and twentyfold increase of claudication distance as well as relief of rest pain. Before starting treatment 6 patients had developed ulcers on their affected limbs; these healed completely in 2, partially healed in another 2, and showed no improvement in the remaining 2, who never stopped smoking. However, immunosuppressive therapy failed to show any improvement of arterial block, as evidenced by radioarteriography and any significant increase of skin temperature over the affected limbs. Nevertheless, histopathologic studies of biopsies taken from the diseased arteries after completion of therapy showed decreased influx of lymphocytes and plasma cells in the thrombi as well as in the arterial walls in comparison to the biopsies taken before the start of treatment. During the treatment the degree of immunosuppression was monitored by blood leukocyte and lymphocyte counts, which were kept between 4,000/mm3 and above 3,000/mm3 and not less than 500/mm3, respectively, indicating modest immunosuppression and no serious complications. All patients were followed up for 1 year. Only 2 patients, who resumed smoking, had relapse.

Possibilities for clinical use of prostacyclin in vascular disease

Currently available drug therapies for patients suffering severe ischaemia with rest pain and trophic lesions of the limbs remain unsatisfactory. Also vascular reopening procedures are suitable in only about half of the patients. In atherosclerotic disease when the vascular endothelium is damaged prostacyclin synthesis is decreased and thromboxane A2 production increases. Prompted by this knowledge of the importance of prostacyclin in pathogenesis of atherosclerotic disease an attempt was made to employ PGI2 clinically--for treatment of advanced forms of peripheral arterial atherosclerotic disease. Favourable effects of the stable analogue of prostacyclin (Iloprost), were reported in various studies, which included patients with peripheral atherosclerotic arterial disease, thromboangiitis obliterans and Raynaud's phenomenon. The use of Iloprost resulted in a significantly superior response than other drugs and placebo in terms of alleviation of rest pain, ulcer healing and decrease of amputation rate of ischaemic limbs. Therefore prostacyclin provides a therapeutic option in patients with advanced forms of arterial disease--including critical ischaemia.

Thromboangiitis obliterans: a rare cause of a reversible Raynaud's phenomenon

A 25-year-old woman with progressive Raynaud's phenomenon and digital necrosis is presented. Systemic sclerosis and other connective tissue disorders as well as atherosclerosis and arterial emboli were excluded with appropriate laboratory examinations. Arteriography revealed multiple palmar and digital occlusions with corkscrew-shaped vessels. Based on these characteristic arteriographic and clinical findings, the diagnosis of thromboangiitis obliterans was finally retained. With intravenous perfusion of the prostacyclin analogue iloprost (2 ng/kg/min, 6 h daily during 21 days), a complete healing of Raynaud's phenomenon and of the digital necrosis was observed. There was no recurrence during the 1-year follow-up. This observation demonstrates that thromboangiitis obliterans is a potential reversible cause of severe Raynaud's phenomenon in young women even in the absence of lower limb involvement. Early recognition is important to avoid irreversible complications such as loss of digits.

[Anticardiolipin antibodies in patients with Buerger's disease]

The aim of this study was to estimate the incidence of occurrence of anticardiolipin autoantibodies in patients with thromboangitis obliterans (TAO). Patients with Buerger's disease had statisticaverified significant higher frequency of anticardiolipin IgM antibodies than control group. This antibody may play a role in pathogenesis of TAO, although this results should be verified because of the small number of patients and diagnostic criteria.

Not adequately assessed

(1) Iloprost, a vasodilatory prostacyclin analogue administered by infusion, is indicated for second-line therapy in patients with severe ischaemia of the lower limbs, when surgical revascularisation fails or is contraindicated. (2) In thromboangiitis obliterans the clinical file on iloprost has remained inadequate since the product was first released. (3) A meta-analysis of 6 clinical trials giving conflicting results in patients with stage III or IV lower-limb arterial disease favoured iloprost. But the results of this meta-analysis are uninterpretable because of methodological biases. It is not known what effects iloprost has in the short term (on pain and skin damage) or in the long term (on the risk of amputation). (4) The iloprost dose must be adjusted individually according to adverse effects linked to vasodilation.

[The role of drug therapy in the treatment of critical ischemia of the lower limbs]

A SERIOUS CONDITION: Critical ischemia results when severe chronic ischemia worsens, creating a threatening situation for tissue survival in the lower limbs. The degree of ischemia is related to the extent of impairment in microcirculation, adding further deleterious effects to stenoses and/or obstructions of the large vessels. MANAGEMENT DIFFICULTIES: Surgery is the mainstay therapy for critical ischemia of the lower limbs. Medical therapy is indicated as first intention treatment in only 10 to 15% of the patients and in a small proportion after partial or total surgical failure when immediate secondary amputation appears to be avoidable. TREATMENTS USED: Antithrombosis agents and drugs with a hemorrheologic effect are used in case of surgical failure or non-indication for surgery. Iloprost is one of the most extensively studied hemorrheology agents. Its use improves the chances of avoiding amputation within a mid-term delay. BUERGER DISEASE: Buerger disease is a specific condition different from the two other major causes (artherothrombosis and diabetes mellitus). The therapeutic management and functional prognosis are much different.

Decrease in prevalence of Buerger's disease in Japan

BACKGROUND

Buerger's disease is a peripheral arterial occlusive disease that is becoming rare in Western countries but is more common in Asia. Whether it is a specific disease entity remains controversial. This study was undertaken to investigate changes in the prevalence and characteristics of Buerger's disease at a major institution in Japan.

METHODS

Patients with Buerger's disease admitted to Nagoya University Hospital between January 1985 and December 1996 were studied retrospectively. Buerger's disease was diagnosed on admission according to Shionoya's clinical criteria.

RESULTS

A total of 105 patients with Buerger's disease were evaluated on 126 admissions; 58 were new patients who were admitted for initial treatment, and 47 patients were experiencing a worsening of Buerger's disease and had a history of prior treatment. Forty-six new patients were admitted between 1985 and 1989, but only 12 new patients were admitted between 1990 and 1996 (9 +/ 3/ yr vs 2+/ 2/ yr, p = 0.0003). Between 1985 and 1989, 44 patients were admitted because of disease exacerbation, whereas only 24 such admissions occurred between 1990 and 1996 (9+/ 3/ yr vs 3 +/ yr, p = 0.0137). The number of admissions for atherosclerotic peripheral vascular disease did not change significantly in that period. Of the 105 patients, the majority (96%) were men; mean age at the time of disease onset was 36 +/ 8 years. The chief complaint on admission was gangrene/ulcer in 64%, rest pain in 13%, foot claudication in 6%, calf claudication in 6%, and other in 10%.

CONCLUSION

The prevalence of Buerger's disease appears to be decreasing at our institution in Japan. Its clinical characteristics have not changed. A similar decrease in prevalence appears to have occurred in Western countries.