Das Lidekzem

Lidekzeme sind pathogenetisch heterogen. Ihre Behandlung ist durch die anatomischen und funktionellen Gegebenheiten der Periorbitalregion erschwert. Dies macht sie, neben ihrer h?ufigen Therapieresistenz und Rezidivneigung, zu einer gro?en diagnostischen und therapeutischen Herausforderung für Haut- und Augen?rzte.Auch ein vergleichsweise kleinfl?chiges Lidekzem kann aufgrund der belastenden Symptomatik und der hohen ?sthetischen Bedeutung dieser K?rperregion einen hohen Leidensdruck verursachen. Diese interdisziplin?re übersichtsarbeit zum Thema behandelt vor allem aktuelle pathogenetische und therapeutische Aspekte der Lidekzeme. Dr.A.Wollenberg Klinik und Poliklinik für Dermatologie und Allergologie der Ludwig-Maximilians-Universit?t München, Frauenlobstr.9-11, 80337 München, E-Mail: wollenberg@lrz.uni-muenchen.de     

Differential expression of tumor necrosis factor and interleukin-6 by peritoneal macrophages in vivo and in culture.

To investigate the differences in cytokine regulation in vitro as compared to in vivo, we examined the synthesis of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) by peritoneal macrophages in response to lipopolysaccharide (LPS). Mice (CBA/J) were primed with an intraperitoneal injection of complete Freund's adjuvant and after 2 weeks, peritoneal cells were harvested for culture or mice were injected intraperitoneally with LPS for in vivo studies. In ascites fluid, TNF-alpha peaked 1 hour after LPS and returned to baseline levels by 4 hours. In contrast, TNF-alpha in the media reached maximum at 7 hours. Expression of TNF-alpha messenger (m)RNA in vivo was rapid but transient, as levels peaked at 15 minutes and returned to baseline 1 hour after LPS. In contrast, TNF-alpha mRNA in vitro became maximal at 1 hour, but remained elevated to 5 hours after LPS. In vivo, IL-6 in ascites fluid peaked at 2 hours, whereas in vitro, IL-6 continued increasing to 24 hours. In vivo, IL-6 mRNA reached maximum at 30 minutes, but fell below baseline by 1.5 hours after LPS. In contrast, IL-6 mRNA in vitro was sustained at maximal expression between 5 to 9 hours after LPS. These results demonstrate that both TNF-alpha and IL-6 synthesis is more rapid in vivo than in vitro. The rapid kinetics of cytokine expression in vivo must considered when designing strategies to inhibit cytokine action in vivo.     

Inverse relationship between epidermal growth factor induced proliferation and expression of high affinity surface epidermal growth factor receptors in rat hepatocytes

Rat hepatocytes express large numbers of high and low affinity surface membrane receptors (EGFR) for epidermal growth factor (EGF) but the roles of EGF and EGFRs in hepatocyte proliferation in vivo are unclear. F344 rat hepatocytes in primary culture proliferated maximally in response to continuous serum-free culture with 3.3 nM (20 ng/ml) EGF, as quantified by cumulative [3H]thymidine labeling index. However, serum concentrations of EGF in rats with normal livers or induced hepatocyte proliferation due to partial hepatectomy, carbon tetrachloride-induced necrosis, or hepatic neoplasia were consistently below 0.1 nM. The 3- or 6-hour pulse exposures to EGF (1.7 nM) between 0 to 16 hours had minimal effect on labeling index at 48 hours, but these pulse exposures at 24 or 32 hours were equivalent to continuous exposure. At 24 and 32 hours, the total specific surface binding of [125I]EGF to hepatocytes cultured free of EGF decreased to 43 and 24% of the initial values, respectively. Scatchard analysis of EGF binding indicated that hepatocytes lost all high affinity EGFRs (Kd of 0.08 nM) by 24 hours. Low affinity [125I]EGF binding at 0 hour (Kd 0.8 nM) was further reduced at 24 hours (Kd = 3.9 nM) and corresponded more closely to mitogenic concentrations of EGF in culture. These studies demonstrate that proliferative responsiveness of hepatocytes to EGF increases during culture by a process that involves prior loss of constitutive high affinity EGFRs. These results suggest that constitutive high affinity EGFRs do not elicit the proliferative response to EGF.     

Identification of a new locus for autosomal dominant non-syndromic hearing impairment (DFNA7) in a large Norwegian family

Hereditary hearing impairment affects about 1 in 1000 newborns. In most cases hearing loss is non-syndromic with no other clinical features, while in other families deafness is associated with specific clinical abnormalities. Analysis of large families with non-syndromic and syndromic deafness have been used to identify genes or gene locations that cause hearing impairment. The present report describes a large Norwegian family with autosomal dominant non-syndromic, progressive high tone hearing loss with linkage to 1q21-q23. A maximum LOD score of 7.65 (theta = 0.00) was obtained with the microsatellite marker D1S196. Analysis of recombinant individuals maps the deafness gene (DFNA7) to a 22 cM region between D1S104 and D1S466. The region contains several attractive candidate genes. This report supports the idea of extensive genetic heterogeneity in hereditary hearing impairment and represents the first localization of a deafness gene in a Norwegian family.      

Multiple cerebral metastases: detectability with Gd-DTPA-enhanced MR imaging

Sixteen patients with suspected cerebral metastases were studied with magnetic resonance (MR) imaging before and after the intravenous administration of 0.1 mmol/kg of gadolinium diethylenetriaminepenta-acetic acid. The images were interpreted blindly by two neuroradiologists; all clinical, radiologic (computed tomographic and MR imaging), and pathologic data were reviewed to arrive at a final "best diagnosis," which was then compared with the prior blinded interpretations. Of seven patients found to have multiple metastases, six (86%) had at least one tumor nodule depicted by postinfusion MR imaging that was missed by one or both observers on review of preinfusion images alone. Lesions missed on preinfusion studies were usually small nodules hidden by or not detected next to regions of high-signal edema thought to be related to the adjacent tumor nodule. The authors believe that contrast enhancement improves detection of metastatic foci with MR imaging and that the findings indicate broader implications for the detection of multiple lesions from other causes.     

CLINICO-EPIDEMIOLOGICAL ALGORITHM FOR PREDICTING SYSTEMIC ARTERIAL HYPERTENSION AT HIGH ALTITUDE THROUGH MATHEMATICAL MODELLING

A population based hybrid design combining element of cohort and cross-sectional approach was used to develop a simple clinical algorithm to predict individual probability of developing hypertension (systolic BP > 140 mm Hg and/or diastolic BP > 90 mmHg). 3615 soldiers initially normotensive at the time of induction into high altitude, were studied by systematic random sampling. Multiple logistic regression analysis showed a high significant association between hypertension and age, body mass index (BMI), tobacco smoking and alcohol consumption. Using the constant/coefficient values obtained from the logistic model and the receiver operating characteristics (ROC) curve analysis, the following predictive rule was developed – To the age in years, add (BMIx 3.86); also add 5.53 if he is a smoker; and add 19.81 if he consumes alcohol. If the total exceeds 142, the individual is at high risk of developing hypertension. This algorithm carries a sensitivity of 68.2% and specificity of 78.5%.KEY WORDS: Hypertension, High altitude