Preoperative functional magnetic resonance imaging (fMRI) of the motor system in patients with tumours in the parietal lobe

Intracranial lesions may compromise structures critical for motor performance, and mapping of the cortex, especially of the motor hand area, is important to reduce postoperative morbidity. We investigated nine patients with parietal lobe tumours and used functional MRI sensitized to changes in blood oxygenation to define the different motor areas, especially the primary sensorimotor cortex, in relation to the localization of the tumour. Activation was determined by pixel-by-pixel correlation of the signal intensity time course with a reference waveform equivalent to the stimulus protocol. All subjects showed significant activation of the primary sensorimotor cortex while performing a finger opposition task with the affected and unaffected side. In five patients the finger opposition task additionally activated the ipsilateral sensorimotor cortex and the supplementary motor area (SMA). Extension and flexion of the foot, additionally performed in two patients, also activated the sensorimotor cortex, in one case within the perifocal oedema of the tumour. Tumour localization near the central sulcus induced displacement of the sensorimotor cortex as compared to the unaffected side in all patients with a relevant mass effect. The results of our study demonstrate that functional MRI at 1.5 T with a clinically used tomograph can reproducibly localize critical brain regions in patients with intracranial lesions.     

A quantitative method for LDH, MDH and albumin levels in tears with ocular surface toxicity scored by Draize criteria in rabbit eyes

We have established a quantitative method for evaluation of ocular surface lesions on the basis of lactate dehydrogenase (LDH) activity, malate dehydrogenase (MDH) activity, and albumin levels in rabbit tears. Lesions were produced with solutions of 0.005-0.02% benzalkonium chloride (BAK), 0.01-0.03% chlorhexidine digluconate (CHX), and 0.01-0.03% polyhexamethylene biguanide hydrochloride (PHMB), all of which are widely used in topical ophthalmic preparations. Two drops of test solution were instilled 15 times into rabbit eyes at 5 minute intervals. Sixty minutes after 0.02% BAK instillation, tear LDH activity increased from 1,840 U/L (without instillation) to 26,100 U/L, and concomitantly tear albumin levels rose from 0.11 mg/mL (without instillation) to 9.48 mg/mL. Instillation of 0.03% CHX and 0.03% PHMB caused smaller increases in LDH and MDH activity and albumin tear levels. LDH activity and albumin levels in tears were significantly correlated with the degree of total ocular surface lesions in both cornea and conjunctiva as observed by slit lamp biomicroscopy quantified using a modified Draize score. Based on the results of this study, we believe that LDH activity and albumin level in tears can be used as objective indicators for the quantitative evaluation of ocular surface lesions on both cornea and conjunctiva following application of topical ophthalmic preparations containing cytotoxic preservatives in animals and man.     

Cartilage-sparing otoplasty: a review with long-term results

Prominent ears are the most frequent congenital deformity in the head and neck region. Anatomy of normal and prominent ears as well as the psychological aspects of prominent ears are reviewed. Two types of surgical technique are described with emphasis on the cartilage-sparing technique. A sound pre-operative analysis, focusing on all parts of the deformity, and surgical techniques which are gradually applied to these deformities should result in pleasing, permanent changes for the vast majority of patients. In our opinion, a combination of cartilage-sparing techniques augmented with cartilage-weakening procedures give predictable long-term results with a natural appearing ear and concomitant few, easily treated complications.     

Cytolytic activity of peripheral blood blast cells from patients with acute myeloid leukemia

The results of the present study demonstrate that cells with the morphologic and phenotypic characteristics of blast cells that are obtained from the peripheral blood of patients with newly-diagnosed or recurrent acute myeloid leukemia (AML) can be stimulated by gamma interferon + lipopolysaccharide (IFN/LPS) to mediate in vitro cytolysis of an NK-insensitive hepatoma cell line. The conditions of IFN/LPS induction and subsequent assessment of cytotoxicity that were employed were identical to those used conventionally to test macrophage-mediated tumor cell cytotoxicity. What was totally unexpected was that these same blast cells, in the absence of stimulation with IFN/LPS, were also found to mediate high levels of spontaneous cytotoxicity against autologous bone marrow cells and against the U937 human promonocytic leukemia cell line in vitro. This high level of spontaneous cytotoxicity against autologous bone marrow or U937 promonocytic leukemia cells was not enhanced by IFN/LPS or MCSF under conditions that stimulated cytotoxic function in normal blood monocytes and was markedly reduced by pretreatment of the blast cells with IL2 under conditions that induced potent NK/LAK-mediated cytotoxicity. Neutralizing antibodies against TNFalpha and/or IL1alpha/beta eliminated the cytolytic function of blast cells against autologous bone marrow or U937 promonocytic leukemia targets. These findings demonstrate the existence of a population of cells with the morphologic characteristics of blast cells in the peripheral blood of AML patients which has the capacity to mediate spontaneous cytolysis of autologous bone marrow cells or a promonocytic leukemia cell line. These cells may be an immature variant of normal precursors produced as a consequence of the disordered hematopoietic environment in the marrow of AML patients. Alternatively, this function may be mediated by a subset of the leukemic blasts themselves.