Mediastinal teratoma in a neonate

A neonate with severe respiratory distress due to a benign mediastinal teratoma (MT) is reported. Despite early and easy surgical excision of the tumor, the child died due to poor cardiac function. Only ten cases of MT in neonates have been reported in the literature so far. While the tumor has been known to interfere with lung development in utero, postnatal myocardial dysfunction due to poor heart development has not been previously documented. Accepted: 22 September 1997     

Osteotomy at the knee for advanced cases of Kashin-Beck disease

Summary. The results of 247 osteotomies at the knee were analysed in 195 patients with Kashin-Beck disease. Since 1983, 37 varus and 210 valgus deformities have been operated on. Supracondylar osteotomy was carried out so that there is a cortical spike in the distal metaphysis which is impacted into the femoral condyle. A U-shaped tibial osteotomy is made 0.5 cm below the growth plate and around the insertion of the patellar ligament. The mechanical axis is corrected and stability obtained by impacting the fragments; internal fixation is not used. Correction of the initial angular deformities was achieved after the osteotomies, and function was improved.

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Résumé. Les résultats de 247 ostéotomies du genou sont analysés sur 195 patients atteints de la maladie de Kashin-Beck. La technique d’ostéotomie utilisée se caractérise, au niveau de la métaphyse distale du fémur, par la réalisation d’une section supracondylienne présentant un ergot cortical et au niveau de la métaphyse proximale du tibia par une section respectant l’insertion du ligament rotulien en la contournant distalement. Vu l’absence de matériel de fixation interne ou externe, l’impaction des fragments permet de stabiliser efficacement la correction de l’axe mécanique. Depuis 1983, 37 genu vara et 210 genu valga ont été ostéotomisés. Les résultats présentent la distribution des déformations angulaires initiales et les corrections obtenues après ostéotomie. L’amélioration fonctionelle confirme l’intérêt de cette technique en l’absence de matériel d’ostéosynthèse.

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Accepted: 23 October 1997     

UVB radiation induces phosphorylation of the epidermal growth factor receptor, decreases EGF binding and blocks EGF induction of ornithine decarboxylase gene expression in SV40-transformed human keratinocytes

Abstract We previously demonstrated that epidermal growth factor (EGF) induces a several-fold increase in ornithine decarboxylase (ODC) activity and the steady-state level of ODC mRNA in cultured SV40-transformed human keratinocytes (1). Pretreatment of cell cultures with ultraviolet B (UVB) radiation resulted in a reduction of EGF-induced ODC activity. To determine whether UVB inhibits the accumulation of ODC mRNA by EGF, cells were pretreated with 20 mJ/cm² UVB or sham-irradiated and then incubated with 100 ng/ml EGF. Northern blot analysis revealed that UVB irradiation entirely blocked the EGF induction of ODC mRNA. Since the binding of EGF to its plasma membrane receptor is the first step in initiating a biological response, the effect of UVB on EGF binding was evaluated. UVB treatment of cultured keratinocytes resulted in an immediate and dose-dependent reduction of EGF binding. Scatchard analysis revealed thai the reduction of EGF binding was due to a 52% decrease in the number of available receptors, from 6.2 × 10⁴/cell to 3.0 × 10⁴/cell. However, UVB decreased the EGF-binding affinity very little (Kd = 0.60 nM in control and Kd=0.75 nM in UVB-treated Z114 cells). In addition, UVB did not alter the rate of EGF internalization. These data suggest that UVB blocks the signal transduction pathway of EGF that is involved in regulation of ODC gene expression. Immunoblot analysis of extracts from irradiated cells showed that UVB induced tyro-sine phosphorylation of EGFR and that the quantity of EGFR protein was unaffected by UVB treatment. Phosphorylation of EGFR may be responsible for decreased binding of EGF to its receptor.     

Advances in development of medications for alcoholism treatment

 Over the past decade, research on medications to treat alcohol problem has flourished. Naltrexone and acamprosate are tangible fruits of such endeavors and each has now earned approval in a large number of countries. Recent studies on naltrexone indicate that patient compliance is important if full benefits are to be achieved. Several laboratory studies with human subjects are beginning to elucidate the mechanisms underlying efficacy of naltrexone, as well as explaining variability of response among subpopulations of drinkers. In addition to these two agents, recent investigations have also demonstrated that the antidepressants desipramine, imipramine, and fluoxetine reduce mood-related symptoms and, to some extent, drinking itself in alcoholics who are depressed. Research to date suggests that opioid antagonists and selective serotonin reuptake inhibitors are more effective in reducing alcohol intake when used in combination. Clinical issues, methodology, and directions for future research are also reviewed in this article. In particular, issues addressed include alternative dosage regimens, necessary duration of treatment, employment of medications in combination, integration of pharmacologic agents with behavioral interventions, enhancement of patient compliance, and concurrent treatment of psychiatric comorbidity. Received: 16 December 1997 / Final version: 15 April 1998     

Visual attention to surfaces in three-dimensional space.

Although attention plays a significant role in vision, its spatial deployment and spread in the third dimension is not well understood. In visual search experiments we show that we cannot easily focus attention across isodepth loci unless they are part of a well-formed surface with locally coplanar elements. Yet we can easily spread our attention selectively across well-formed surfaces that span an extreme range of stereoscopic depths. In cueing experiments, we show that this spread of attention is, in part, obligatory. Attentional selectivity is reduced when targets and distractors are coplanar with or rest on a common receding stereoscopic plane. We conclude that attention cannot be efficiently allocated to arbitrary depths and extents in space but is linked to and spreads automatically across perceived surfaces.     

Application of anterior pituitary cell culture in toxicological research.

High density plating procedure was used to evaluate the effect of atrazine on anterior pituitary cells of rats in monolayer culture. Collagenase-dispersed pituitary cells plated in suspension with medium-199 and 10% foetal calf serum attached quantitatively to plastic surfaces within 24 hours. Electron microscopy showed subpopulations of different cell types. After prolonged cultivation, most cells established small colonies with extensive contacts among them. Cell-to-cell formation of aggregates was significant and the colonies manifested morphological changes. The cells retained their enzymatic activity, converting testosterone into 5 alpha-dihydrotestosterone by enzyme 5 alpha-reductase. Immunohistochemical techniques facilitated differentiation of gonadotrophs producing follicle stimulating hormone (FSH) and luteinising hormone (LH). Atrazine in concentrations of 5 to 50 micrograms/ml of medium was associated with a significant reduction in the number of viable cells within 72 hours. The results suggest that the pituitary cell culture may prove useful in toxicological testing of various toxic compounds and reduce or replace in vivo animal experiments.     

Cytokines and adhesion molecules in renal vasculitis and lupus nephritis

Background: Plasma levels of some pro-inflammatory cytokines and soluble adhesion molecules have been suggested to be useful parameters to assess the activity of antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis and lupus nephritis. We hypothesized that the renal activity of these diseases is better reflected by the urinary excretion and fractional excretion of these molecules. Methods: Plasma levels and urinary excretion of tumour necrosis factor-&agr; (TNF-&agr;), interleukin (IL)-6, IL-8, and the soluble cell adhesion molecules sICAM-1 and sVCAM-1 were measured by enzyme-linked immunosorbent assay (ELISA) in 15 patients with ANCA-positive renal vasculitis (eight active, ANCA-A; six in remission, ANCA-R), six patients with active lupus nephritis (LN), 15 patients with IgA nephropathy (IgAN) and nine healthy subjects. Fractional excretion of selected cytokines and adhesion molecules was also calculated. Results: Patients with ANCA-A had increased urinary excretion and fractional excretion of TNF-&agr; (9.27±3.19% vs 0.58±0.02%, P<0.01), IL-6 (120.79±65.83% vs 1.89±0.34%, P<0.01) and increased fractional excretion of IL-8 (23.34±6.38% vs 2.56±1.07%, P<0.01) and sVCAM-1 (0.81±0.33% vs 0.03±0.02%, P<0.01) compared with controls. Urinary excretion of TNF-&agr; and IL-6 and fractional excretion of TNF-&agr;, IL-6 and IL-8 were higher in ANCA-A than in ANCA-R. Patients with LN had increased plasma TNF-&agr; (20.52±2.01 pg/ml vs 12.33±0.23 pg/ml, P<0.05) and sVCAM-1 (1537.88±276.36 ng/ml vs 692.26±44.42 ng/ml, P<0.05) and increased urinary excretion of TNF-&agr; (2.81±0.51 &mgr;g/mol creat vs 0.98±0.05 &mgr;g/mol creat, P<0.01), IL-8 (35.78±14.03 &mgr;g/mol creat vs 12.46±5.19 &mgr;g/mol creat, P<0.05) and sVCAM-1 (48.98±20.20 &mgr;g/mol creat vs 2.92±1.35 &mgr;g/mol creat, P<0.01) compared with controls. Patients with IgAN had, in comparison with controls only increased plasma TNF-&agr; (18.10±0.57 pg/ml vs 12.33±0.23 pg/ml, P<0.05). Conclusions: Urinary excretion and fractional excretion, but not plasma levels of selected proinflammatory cytokines (TNF-&agr;, IL-6 and IL-8) were increased in patients with active ANCA-positive renal vasculitis, but not in ANCA positive vasculitis in remission. These parameters may be useful to monitor the activity of this disease.     

Averaged axillary F-loop latency of median and ulnar nerves

Axillary F-loop latencies (AFLL) were measured on median and ulnar nerves of 54 normal volunteers. The median and ulnar nerves were stimulated at the wrist and at the axilla 25cm distal to the sternal notch. The compound muscle action potentials were recorded from thenar and hypothenar muscles. Averaged tracings from 32 consecutive stimuli at the wrist were obtained. The averaged F-wave latencies were measured to the peak (Fwp) of the averaged F-wave. The M-wave latencies from wrist and axilla stimulation were measured to the onset of the wave (Mw and Ma, respectively). The averaged AFLL (a-AFLL) was calculated as (Fwp + Mw)-2 Ma. The average values of a-AFLL were 14.12 +/- 0.88msec for median nerve, and 13.97 +/- 0.90msec for ulnar nerve. There was no significant difference between male and female subjects, nor between the right and left sides. Seven subjects with EMG evidence of C8 or C8 to T1 radiculopathy, although manifesting normal AFLL gauged by the regular method (ie, measured to the onset of the shortest F-wave latency among eight tracings), had significantly longer "averaged AFLL" in both median and ulnar nerves of the affected side than the a-AFLL obtained from the normal side. It is concluded that the a-AFLL is a more sensitive measure than the "regular AFLL" in the assessment of proximal nerve lesion (especially C8 or C8 to T1 radiculopathy).