Biomedical subjects
Publications and source records attributed to M R Dix.
The central compensation mechanisms for vertigo resulting from vestibular lesions are described together with the scientific basis for head exercises in vestibular rehabilitation. The indications and contra-indications for head exercises are discussed and the Cawthorne-Cooksey regime of exercises illustrated.
An increased incidence of E. coli sepsis has been observed in neonates given intramuscular iron-dextran for prevention of iron deficiency. Mechanisms for this apparent effect on susceptibility to infection were investigated by comparing phagocytic and antibacterial functions in paired samples of venous blood from 7 infants, median age 5 days, before and after iron-dextran. Post-treatment sera had increased inhibitory effects on leucocyte chemotaxis and markedly reduced bacteriostatic effects agaainst E. coli. The clinical relevance of the effects on chemotaxis is uncertain. The reduction in serum bacteriostasis is similar to that observed in other forms of hyperferraemia not associated with saturation of transferrin, and is a likely cause of the increased susceptibility to infection in vivo. We consider that prophylactic treatment with parenteral iron-dextran is contraindicated in early infancy.
Explore the source record for details and available documents.
A comprehensive review is presented of the ototoxic effects of drugs which may damage hearing. These have been classified in tabular form together with the recommended dose, method of administration, and ill-effects upon the inner ear. Special emphasis is laid upon the hazard of prescribing such drugs in certain conditions, including in particular the presence of renal or hepatic insufficiency, and the importance of laboratory assessment of new antibiotics for ototoxicity before undertaking clinical trials.
Chronic granulomatous disease, in which abnormal susceptibility to infection is caused by an inherited defect in phagocytic cells, has been diagnosed in three brothers. Two brothers had repeated bacterial infections of the skin, superficial lymph nodes and lungs from infancy and died aged 27 months and 13 months. Characteristic suppurating granulomata were found in many organs. The diagnosis was established in both during life, and in the third asymptomatic brother shortly after birth, by studies of phagocytic function which included tests for nitroblue-tetrazolium reduction, hexose monophosphate shunt activity and bactericidal capacity. Their mother and a maternal aunt, both Maoris with no known Caucasian ancestry, were identified as carriers of the presumed sex-linked recessive gene. The clinical features of the disease and the laboratory methods for diagnosis are described.
Abnormalities of optokinetic nystagmus are described in a patient with pathologically proven bilateral infarcts in the middle cerebral artery territories. There were no other central nervous system lesions. These abnormalities of eye movement are interpreted as indicating an inhibitory effect of the frontal eye fields upon the occipital lobes.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A 16-month-old boy presented with cervical lymphadenopathy and a mediastinal mass causing tracheal displacement. Treatment of what at first was suspected to be a malignant neoplasm was limited to low-dose irradiation of the mediastinum and biopsy excision of the cervical lymph nodes. There has been no recurrence of disease in the subsequent four years. The pathological features and clinical course correspond to a benign disease first described in 1969 in which there is massive proliferation of histiocytes in lymph node sinuses. No infectious cause was identified. Consistent but eventually reversible defects in lymphocyte response to phytohaemagglutinin and in augmentation of nitro-blue tetrazolium reduction by neutrophils during phagocytosis were demonstrated in the patient and in his monozygous twin. These defects in cellular immune function are believed to be important in the pathogenesis of the histiocytosis.
Claims are often made that the electronystagmographic recording of induced nystagmic responses either with eye closure or in darkness enhances the sensitivity of the test. While this may be true of certain parameters it is not true of all and may in fact lead to a reduction in the diagnostic information obtainable with optic fixation upon a target.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The many vestibular tests now available provide the means of accurate localization of lesions at all levels of the vestibular pathways. The value of the test procedures described has been well established in the examination of very many patients over the past twenty years, and though other forms of tests are available only those have been included which have proved to give consistently useful information.Most of these tests can be undertaken by the clinician without the use of any costly equipment, and together with a careful history and examination the diagnosis can in most cases be arrived at. Recognition of the highly important role of optic fixation and ocular deviations on vestibular nystagmus, together with recent facilities to demonstrate this electronystagmographically, may provide additional valuable and more precise information.
Explore the source record for details and available documents.
Explore the source record for details and available documents.