Three-dimensional organization of vestibular related eye movements to rotational motion in pigeons

During rotational motions, compensatory eye movement adjustments must continually occur in order to maintain objects of visual interest as stable images on the retina. In the present study, the three-dimensional organization of the vestibulo-ocular reflex in pigeons was quantitatively examined. Rotations about different head axes produced horizontal, vertical, and torsional eye movements, whose component magnitude was dependent upon the cosine of the stimulus axis relative to the animal's visual axis. Thus, the three-dimensional organization of the VOR in pigeons appears to be compensatory for any direction of head rotation. Frequency responses of the horizontal, vertical, and torsional slow phase components exhibited high pass filter properties with dominant time constants of approximately 3 s.     

PKC isoenzymes in the chicken lens and TPA-induced effects on intercellular communication

PURPOSE: Because lens connexins are phosphoproteins and intercellular communication between lens cells may be modulated by connexin phosphorylation, experiments were designed to characterize the expression of protein kinase C (PKC) isoenzymes in the chicken lens and in lentoid-containing cultures and to study the effects of 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment on the distribution of PKC isoenzymes and intercellular communication. METHODS: The presence and distribution of PKC isoenzymes were studied by immunoblot analysis and immunofluorescence in chicken lens sections and in cell cultures under control conditions and after treatment with TPA. Intercellular communication was assessed by transfer of microinjected Lucifer yellow. RESULTS: PKC alpha, gamma, iota, epsilon, and mu were detected in lens homogenates by immunoblot analysis. The levels of PKC alpha, gamma, iota, and mu decreased between the 7th and the 18th embryonic days. Levels of PKC epsilon remained relatively constant during the period of study. Similarly, lens cells in culture expressed isoenzymes alpha, gamma, epsilon, iota, and mu. PKC beta was not detected in lens or culture homogenates. In lens sections, all PKC isoenzymes analyzed were present in epithelial cells, in the annular pad region, and in the posterior aspect of fiber cells. The anti-PKC gamma antibody also stained fiber cell membranes. Analysis of lentoid cultures by immunofluorescence revealed that PKC gamma, epsilon, and iota and minimal amounts of PKC alpha were present in lentoid cells. Treatment with 200 nM TPA for 15 to 30 minutes induced translocation of PKC gamma to the plasma membrane of lentoid cells and significantly reduced the transfer of microinjected Lucifer yellow. CONCLUSIONS: Several PKC isoenzymes are expressed by lens cells in situ and in culture. The gamma isoenzyme, present in lens fibers, was activated in lentoid cells by TPA, a known activator of PKC. We have previously demonstrated TPA-induced phosphorylation of the gap junction protein connexin56 (Cx56). The new data presented in the current study demonstrate that TPA treatment also decreased intercellular communication. Taken together, the results suggest that differential phosphorylation of Cx56 by PKCgamma may induce a conformational change in the protein which, in turn, might lead to channel closure.     

Unusual progression of a Legionella pneumophila infection in a young child

A 2 8/12-year-old boy showed an unusual course of a Legionella pneumophila infection with severe dyspnea, longterm loss of conscience (5 days) and permanent persistence of pulmonary obstruction.     

Results of primary chemotherapy in 44 patients with advanced squamous cell carcinoma in the area of the head and neck

44 patients with advanced squamous cell carcinoma of the head and neck were randomized and treated preoperatively either with arm "A": cis-DDP (3 mg/kg iv day 1) and BLM (15-20 mg iv continuously day 2-6) or arm "B": MTX (30 mg/m2 iv day 1 + 6) and VDS (3 mg/m2 iv day 2 + 7). Treatment with arm "A" was superior producing 73% complete and partial remissions (CR + PR) compared to 40% for arm "B" (p = 0,05). The number of patients with CR could be increased from 2 to 26 by surgery and/or radiotherapy. The median survival for patients with chemotherapeutically induced CR and PR was 16 months but this did not differ significantly from the median survival (13 months) of non responders (p = 0.25). For patients with CR and PR achieved by surgery and/or x-ray therapy the median survival point has not yet been reached, and this is significant compared to the non responders (p = 0.001). Five of 26 patients with CR died after 39 months of observation and 6 are living with recurrence. In addition to clinical trials, chemotherapy is indicated for patients with inoperable tumours. The value of chemotherapy can only be answered by randomized trials comparing chemotherapy combined with standard procedures against surgery and radiotherapy alone.     

Gap junction synthesis and degradation as therapeutic targets

The synthesis and the degradation of gap junctions involve multiple steps that may provide targets for the modulation of intercellular communication. Many studies using cultured cells have examined the effects of inhibitors of protein synthesis, trafficking, or degradation upon connexins. Similarly, activators or inhibitors of various protein kinases have been shown to affect connexin assembly or proteolysis. These studies have helped to elucidate the connexin life-cycle. But, because of their lack of specificity for gap junction proteins, these agents would be expected to have limited therapeutic utility and to produce several deleterious side effects. However, more selective agents are being developed based on specific features of the connexin sequences. Molecular genetic approaches have been used to introduce wild-type connexins to increase intercellular communication in otherwise poorly coupled cells. Decreased intercellular communication may be obtained by application of peptides that mimic the extracellular loops and may prevent docking of hemi-channels. Alternatively, introducing mutant connexins that interfere with the oligomerization/export of endogenous connexins or with channel function by formation of non-functional heteromeric hemi-channels can also reduce intercellular communication.     

Rheopheresis in patients with ischemic diabetic foot syndrome: results of an open label prospective pilot trial

Rheopheresis is a specific application of membrane differential filtration, synonymous with double filtration plasmapheresis, for extracorporeal hemorheotherapy. Safety and efficacy of Rheopheresis for wound healing and skin oxygenation were investigated in patients with ischemic diabetic foot syndrome. Eight patients with type 2 diabetes mellitus and non-healing foot ulcers caused by severe ischemic diabetic foot syndrome were treated by a series of seven Rheopheresis sessions in a time span of 11 weeks. Wound healing had not been detectable under conditions of standardized wound care during at least 2 months. Wound status was classified by its morphology, severity and location, according to the criteria of Wagner. Transcutaneous oxygen pressure (tcPO2), laser Doppler flowmetry and vital capillary microscopy were repeatedly performed to monitor the effects of the Rheopheresis treatment series on microcirculation and skin blood flow. Laboratory parameters of blood rheology, endothelial function and inflammatory state were measured in addition to safety parameters. In four patients (baseline Wagner stage 2), Rheopheresis accelerated wound healing of foot ulcers and was associated with an improvement of Wagner stage and a pronounced increase in tcPO2. In two patients (baseline Wagner stage 2), wound healing was unchanged but mean tcPO2 increased, allowing successful minor amputation. Values of tcPO2 remained stable and enhanced for the 3 months follow-up period. In two patients (baseline Wagner stage 4 or 5), no improvements in foot lesions were observed within the treatment period. As an adjunct therapeutic option, Rheopheresis may preserve a functional lower extremity, delay amputation or reduce the extent of amputation.     

Bioavailability of metals to the amphipod Monoporeia affinis: interactions with authigenic sulfides in urban brackish-water and freshwater sediments

Could reduced eutrophication be a potential environmental threat because of increased mobility and bioavailability of trace metals? This question was addressed by oxygenating intact sediment cores, varying in redox potential and salinity, in a test system containing the amphipod Monoporeia affinis. Results show a low mobility of metals during oxygenation, and despite high concentrations of metals in sediments, only Pb showed a notable degree of bioaccumulation. Cadmium was bioaccumulated particularly in freshwater sediment, and body burden of Cd was related to salinity, porewater, and sediment concentrations. Despite high sediment and porewater concentrations of Cu and Zn, no relationship was recorded to body burden. For three of four tested metals, Cd, Pb, and Zn, metals in sediment were more important for body burdens in amphipods as compared to metals in porewater. Food, rather than interstitial water, therefore seems to be the main route of metal contaminants to these amphipods. Furthermore, this observed low release of metals from sediments and low body burden significance of porewater metals indicate that ameliorated oxygen conditions in contaminated sediments may be regarded as a minor environmental threat for one of the most important Baltic benthic organisms.     

Prominent pruritic periumbilical papules: allergic contact dermatitis to nickel

We report a case series of 38 children with suspected allergic contact dermatitis (ACD) to nickel who presented with prominent subumbilical and periumbilical papules and a generalized, lichenoid papular dermatitis resembling an id reaction. We speculated that this was an ACD to nickel and performed patch tests in 9 (24%) of these patients. All 9 (100%) patients had positive patch test results for nickel, thus confirming the diagnosis.     

No increase of plasma malondialdehyde after primary coronary angioplasty for acute myocardial infarction

OBJECTIVE: Free radicals formed after coronary artery occlusion and reperfusion are assumed to produce myocardial stunning and possibly other forms of reperfusion injury as well. Malondialdehyde (MDA) is an end product in the lipid peroxidation chain reaction and is frequently used as a marker for free oxygen radical production. Increased levels of plasma MDA have been found following successful thrombolytic therapy. The aim of this study was to investigate whether plasma MDA levels also increase after successful primary percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (AMI). DESIGN: In 23 patients with AMI, treated with primary PTCA, plasma MDA was analysed using a high-performance liquid chromatography method (HPLC). The results obtained with this method were compared with those obtained with a fluorimetric assay of thiobarbituric acid reactive substances (TBARS). This assay measures MDA but with a lower specificity. RESULTS: We found a significant decrease of plasma MDA from baseline 0.99 to 0.87 micro mol/l at 30 min and to 0.90 micro mol/l at 90 min following the primary PTCA (p = 0.048 and 0.014, respectively). No significant changes in TBARS method levels were observed. CONCLUSION: Instead of the expected increase in MDA following reperfusion we found a significant decrease. The results from measurements of MDA and TBARS were significantly incompatible. The results raise serious doubts as to the usefulness of increased plasma levels of MDA as a marker of oxidative stress caused by coronary reperfusion in patients treated with angioplasty.