THE EFFECT OF TUBOCURARINE ON ULNAR NERVE CONDUCTION VELOCITY

Nerve conduction velocity was studied in the ulnar nerve ofhuman subjects during general anaesthesia. An increase in velocityof between 1.9 and 4.8 per cent occurred following the administrationof paralytic doses of tubocurarine to subjects receiving nitrousoxide, oxygen and halothane anaesthesia in whom ventilationwas controlled. This increase in velocity did not appear tobe related to a change of subcutaneous temperature.     

INHIBITION OF THE PLASMA CHOLINESTERASE VARIANTS BY PROPRANOLOL

The inhibitory effect of( ±)propranolol 1.69 x l0^–4–l.69x 10^–7 mol litre^–1 on normal and atypical plasmacholinesterase variants was investigated. The atypical enzymeis less sensitive to inhibition by (±) propranolol oreither of its enanticasiorphs than the usual enzyme. Propranolol8.45 x 10^–6 mol litre^–1 was used as differentialinhibitor of 643 plasma samples from individuals of known genotype.Although the measurement of propranolol inhibition alone isnot always unambiguous for assigning a definite genotype toa given individual, the correlation of propranolol inhibitionwith fluoride inhibition gives clear differentiation of theE₁^uE₁^u and E₁, as well as other phenotypes.     

ANALYSIS OF SUXAMETHONIUM SENSITIVITY FOLLOWING TERMINATION OF PREGNANCY

The choiinesterase genotypes in the majority (25135) of patientswith suxamethonium sensitivity foilowing termination of pregnancyare heterozygotes with an Exa gene. Tweive of these patientshave the genotype EXUE{. The reported duration of apnoea isminimal in the heterozygotes iacking the Exa gene (about 5–10min) and maximal in the homozygotes EfEf (about 35 min). Withfew exceptions, the heterozygotes having an E1a gene are apnoeicfor 10–15 min. The apparent low frequency of suxamethoniumin these patients is discussed.     

Erythromelanosis follicularis faciei et colli

Erythromelanosis follicularis faciei et colli was first described by Kitamura and colleagues in 1960¹. However, the condition has only rarely been reported in Caucasians. This syndrome, of unknown aetiology, characteristically occurs in adolescent males and is asymptomatic. We report a case of erythromelanosis follicularis faciei et colli in a 15-year-old male patient. The histological features and differential diagnosis are discussed.     

Mitochondrial diseases in childhood: a clinical approach to investigation and management

Mitochondrial diseases are a common cause of inherited neurological disorders in children. Although dysfunction of the central nervous system is prominent, multisystem involvement also occurs. Diagnosis relies on characteristic clinical features, an understanding of mitochondrial genetics, and a logical, informed approach to investigations. There is a significant body of recent literature on advances in mitochondrial genetics and the investigation of mitochondrial diseases. However, to our knowledge there remains a paucity of published information on the management of these disorders. Management of the complex constellation of neurological and multisystem clinical features is challenging, and is reliant on a multidisciplinary approach. The care of the child and family is dependent on clear communication between health professionals from primary, secondary, and tertiary care as well as specialist input from quaternary services. The aim of this review is to provide paediatric neurologists, paediatricians, and allied health professionals with a structured approach to the diagnosis and management of children with suspected or confirmed mitochondrial disease.     

MALIGNANT HYPERTHERMIA AND THE FLUORIDE-RESISTANT GENE

One hundred and six individuals from 33 families with a historyof malignant hyperthermia have been investigated for plasmacholinesterase variants. An increased frequency of the fluoride-resistantgene has been found. Although an adequate explanation for ourresults is elusive, some hypotheses are discussed.     

Cutaneous necrosis associated with the antiphospholipid syndrome and mycosis fungoides

Summary The development of extensive cutaneous necrosis in a patient with tumour-stage mycosis fungoides is described. Skin biopsies showed a lymphomatous infiltrate, and thrombosis of dermal blood vessels. Investigation revealed the presence of anticardiolipin antibodies, a lupus anticoagulant, and low free protein S, which contributed to a prothrombotic state. Antiphospholipid antibodies have been detected in non-Hodgkin's lymphoma, but clinical manifestations are uncommon. Such autoantibodies may be produced by neoplastic lymphoid cells. The frequency with which antiphospholipid antibodies occur in mycosis fungoides is currently unknown.     

Eosinophilic granuloma of lymph nodes

Two examples are reported of eosinophilic granuloma presenting as lymphadenopathy and being apparently confined to lymph nodes. The affected nodes were characterized by a striking sinus histiocytosis, a heavy infiltration with mature eosinophils and retention of normal lymphoid follicles. The differential diagnosis of this histological picture is discussed and the prognosis considered.