[New anticoagulants - direct factor Xa-inhibitors]

The direct oral factor Xa-inhibitors are at present in clinical use as antithrombotics, after their efficiency and safety have been proved in clinical studies. Three products are actually in the market, rivaroxaban (Xarelto®) apixaban (Eliquis®) and edoxaban (Lixiana®). Efficacy and safety have been tested for rivaroxaban and apixaban in large study programmes with more than 60'000 patients each. For edoxaban large phase III studies are under way. Based on these data rivaroxaban was registered in the EU and CH for primary prophylaxis against thrombosis after major orthopaedic surgery, such as hip- and knee-joint protheses, for treatment and prophylaxis of deep vein thrombosis and pulmonary embolism and for prophylaxis against thromboembolic stroke in patients with atrial fibrillation. Apixaban is presently registered in the EU and CH for prophylaxis against thrombosis after major orthopaedic surgery, Edoxaban is registered only in Japan for the same indication. These products have been shown to be non-inferior or superior compared with vitamin K antagonists or low-molecular weight heparins, they are administered once or twice a day, they do not need laboratory monitoring. But they have disadvantages also, they depend on renal clearance, they can interact with other medicaments and they lack a specific antidote. In total, though, they are considered as a progress for the appropriate patients in terms of quality of treatment.

Establishment and characterization of an arsenic-sensitive monoblastic leukaemia cell line (SigM5)

Few human monoblastic cell lines have been characterized to date. We have established the SigM5 cell line from a patient with acute monoblastic leukaemia (FAB M5a). Original leukaemic cells had a karyotype of 47,XY,+8, whereas the cell line showed a stemline clone of 81,XX,Y,Y,1,4,6,7,+8,+8,9,10,10,11,13,16,19[cp], with a minor sideline also present. Cytochemical staining was strongly positive with alpha-naphthylbutyrate acetate esterase, particulate positive with Sudan black and weakly positive for myeloperoxidase. Cells were positive for CD13, CD15, CD18, CD23, CD33, CD38, CD45, CD68 and myeloperoxidase. CD14 expression was 3-15%. SigM5 constitutively secreted interleukin (IL)-2, IL-8, IL-10, tumour necrosis factor (TNF)-alpha, ferritin, lysozyme, N-elastase and neopterin upon stimulation with interferon (IFN)-gamma. Cells expressed the proinflammatory mediator macrophage migration inhibitory factor (MIF). All NADPH oxidase subunits were constitutively present, but nitroblue tetrazolium reduction was only detectable upon activation with IFN-gamma. SigM5 monoblasts were sensitive to arsenic trioxide (As2O3) previously not described to induce apoptosis in monoblastic cells. Differing considerably in morphology, immunophenotype and sensitivity to arsenics from the widely used cell lines U937, HL-60 and THP-1, SigM5 is a new monoblastic cell line useful for studying leukaemogenesis, monocyte differentiation and tumour cell susceptibility to arsenic compounds.

[Diagnosis of vitamin B12 deficiency: only apparently child's play]

We performed a systematic literature search for diagnostic criteria in establishing cobalamin deficiency. The diagnostic procedure is particularly uncertain in elderly patients with neurological symptoms and in cases with borderline cobalamin values. In any patient with suspected cobalamin deficiency we recommend analysing a full blood count and determining cobalamin concentration in a serum sample. Particularly in elderly patients and cases with neurological symptoms presenting borderline cobalamin values and no abnormalities in the blood count, we recommend further investigation with methylmalonic acid, homocystein and Schilling test. These additional tests should make it possible to decide whether to recommend lifelong substitution with cobalamin. Various cobalamin assays, Schilling test, food cobalamin test, gastroscopic evaluation and the problems surrounding these assays in the elderly are discussed. Our own experience with methylmalonic acid, homocystein determination and food cobalamin test did not reveal a simple diagnostic procedure in such cases. We conclude that there is still no "gold standard" for diagnostic procedure in the special cases mentioned.

[Visceral and neurological complications in Varicella infections of adults]

Primary varicella-zoster virus (VZV) infections in adults generally follow a more severe course than in children and are more often associated with life-threatening complications. In the years 1992 to 1995 we observed 7 immunocompetent adults with a severe course of primary VZV infection. All 7 patients presented initially with a characteristic rash. In 6 patients the diagnosis of VZV was confirmed by ELISA on material taken from the lesions, and in all of them it was confirmed by serology. The following complications were observed: pneumonia (5x), elevated liver enzymes (4x), myocarditis (1x), encephalitis (1x) and myelitis (1x). Pulmonary lesions were characterized by bilateral interstitial infiltrates on chest-x-ray and required mechanical ventilation in 2 patients. The liver enzymes were only slightly elevated and clinically not significant. Myocarditis in one case was postulated in view of elevated creatine kinase levels, ECG-repolarization changes and AV-block III which required the insertion of a transitory pacemaker. Encephalitis presented as abnormal behaviour at work followed by seizures. Myelitis was suspected due to ascending sensory motor tetraparesis and confirmed by MRI. All patients were treated with high doses of parenteral acyclovir (3 x 10 mg/kg body weight i.v. per day) for 5-12 days. 6 patients recovered completely and only the patient with myelitis has residual neurological deficits 3 months after discharge. Although we cannot exclude the possibility that supportive therapy without acyclovir would have had the same outcome, we recommend high-dose parenteral acyclovir for treatment of visceral and neurological complications in primary VZV infections in adults.

[Differential diagnostic aspects of progressive spastic paraplegia in adults with emphasis on neurometabolic diseases]

The differential diagnosis of a progressive spastic paraparesis in the young adult is broad and includes rare neuro-metabolic diseases like cerebro-tendinous xanthomatosis, adrenomyeloneuropathy and hypovitaminosis. Their clinical presentation as well as the result of paraclinical examinations can be similar to those of multiple sclerosis. The early recognition of these diseases is important, because a dietary regimen may reduce the severity and progression of symptoms and signs and genetic counselling can be important. The relevant biochemical examinations for their detection are discussed. These neuro-metabolic diseases have to be differentiated from other neuro-degenerative diseases like amyotrophic lateral sclerosis and hereditary spastic paraplegias.

[Akinetic crisis in Parkinson disease]

The akinetic crisis is an "off" state that lasts more than 48 hours with akinesia, rigidity and bradykinesia, occurring with signs of CNS dysregulation in advanced stages of Parkinson's disease. 7 akinetic crises lasting 4 to 14 days (average 9.3) were observed in 744 hospitalizations over a period of 7 years. The age of the patients with akinetic crisis and the mean duration and the severity of the disease were significantly higher than in the other patients. While bradykinesia and rigor are the most relevant clinical signs in some 40% of parkinsonian patients, 6 of our 7 patients (86%) had an akinetic-rigid form of the disease. Levodopa withdrawal preceded the akinetic crisis in 4 patients: in 3 patients the akinetic crisis occurred despite adequate dopaminergic therapy, in one patient after benzodiazepine withdrawal, in another case after gastrointestinal bleeding, and in one case without known cause. Hyperthermia, tachycardia and sweating were the most common collateral manifestations. Apomorphine given subcutaneously was effective in four cases, apomorphine and amantidine were effective in one case, and one patient died during an akinetic crisis. The akinetic crisis is a distinct form of motor fluctuation in advanced stages of Parkinson's disease, with clinical signs resembling malignant neuroleptic syndrome (NMS). While NMS is related to dopaminergic receptor blockade or dopaminergic depletion, akinetic crisis can occur despite adequate dopaminergic therapy as a symptom of severe basal ganglia dysfunction related to the advanced stages of Parkinson's disease. Outcome and therapy of akinetic crisis depend on the underlying causes.

[Differential diagnosis of chronic gait disorders of neurologic origin in old age]

The differential diagnosis of chronic gait difficulties with falls in the elderly, due to neurological diseases, is discussed. The spectrum is quite wide and encompasses central and peripheral pathologies of the nervous system. For centrally induced gait difficulties auxiliary examinations correspond to those used in the evaluation of dementia.