Comprehensive investigation of saliva replacement liquids for the treatment of xerostomia.

The sensation of dry mouth also referred to as xerostomia is becoming increasingly common worldwide. Current treatment strategies include topical agents, sialagogues and saliva substitutes. The latter have been reported to be ineffective as special physicochemical features of natural saliva have so far been ignored (e.g., buffer capacity, osmolality, etc.). The aim of this study was to comprehensively investigate the most relevant physicochemical properties of three products frequently used in the clinics and compare them to unstimulated whole saliva (UWS). Sialin-Sigma®, Glandomed® and Xylitol CVS HealthTM Dry Mouth Spray were characterized regarding their pH, osmolality, electrical conductivity, buffer capacity, rheological behaviour, microstructure, surface tension and wettability and compared to UWS. The influence of residual saliva was examined under consideration of the conditions of xerostomia to assess whether the quantity given in the instruction for use is appropriate. All three products showed significant differences to UWS regarding the values received. Only Xylitol CVS HealthTM Dry Mouth Spray showed a comparable wettability. It could be further determined that the recommended doses were too low. These data can not only be used for an improved understanding of saliva, but also for the development of a replacement fluid to successfully alleviate xerostomia.

Land use change impacts on floods at the catchment scale: Challenges and opportunities for future research.

Research gaps in understanding flood changes at the catchment scale caused by changes in forest management, agricultural practices, artificial drainage, and terracing are identified. Potential strategies in addressing these gaps are proposed, such as complex systems approaches to link processes across time scales, long-term experiments on physical-chemical-biological process interactions, and a focus on connectivity and patterns across spatial scales. It is suggested that these strategies will stimulate new research that coherently addresses the issues across hydrology, soil and agricultural sciences, forest engineering, forest ecology, and geomorphology.

Impact of constant storage temperatures and multiple warming cycles on the quality of stored red blood cells.

BACKGROUND: Red blood cells (RBCs) are routinely stored in liquid state at temperatures below 6°C, and RBC unit core temperature should not exceed 10°C during transport. Since the critical temperature of 10°C was chosen mostly arbitrarily, this study investigated the effect of both constant temperature settings as well as multiple rewarming cycles on stored RBCs with respect to morphology, biochemical parameters and haemolysis. MATERIALS AND METHODS: Buffy coat-depleted filtered RBCs were used as standard products. RBCs were stored at 1-6°C (reference group, n = 12), 13 and 22°C (test groups, n = 12 each) or stored at 1-6°C and warmed up five times to 10, 13, or 22°C for a period of 24 h each. Various biochemical parameters were measured weekly. RBCs were further investigated using electron microscopy. RESULTS: Red blood cells stored constantly at 13 or 22°C showed stable haemolysis rates until day 28 and day 14, respectively. RBCs stored at 1-6°C with five warming-up periods to 10, 13 or 22°C each lasting 24 h (total 120 h) did not exceed the limit of the haemolysis rate at the end of storage. Differently shaped erythrocytes were found in all samples, but more crenate erythrocytes appeared after 42 days of storage independent of temperature profiles. CONCLUSION: Red cells can be kept at constant temperatures above 6°C without apparent harmful effects at least until day 14, whereas multiple warming cycles for no longer than 24 h at 10, 13 or 22°C with subsequent cooling do not cause quality loss as assessed using the in vitro assays employed in this study.

In vitro formation and activity-dependent plasticity of synapses between Helix neurons involved in the neural control of feeding and withdrawal behaviors.

Short-term activity-dependent synaptic plasticity has a fundamental role in short-term memory and information processing in the nervous system. Although the neuronal circuitry controlling different behaviors of land snails of the genus Helix has been characterized in some detail, little is known about the activity-dependent plasticity of synapses between identified neurons regulating specific behavioral acts. In order to study homosynaptic activity-dependent plasticity of behaviorally relevant Helix synapses independently of heterosynaptic influences, we sought to reconstruct them in cell culture. To this aim, we first investigated in culture the factors regulating synapse formation between Helix neurons, and then we studied the short-term plasticity of in vitro-reconstructed monosynaptic connections involved in the neural control of salivary secretion and whole-body withdrawal. We found that independently of extrinsic factors, cell-cell interactions are seemingly sufficient to trigger the formation of electrical and chemical synapses, although mostly inappropriate--in their type or association--with respect to the in vivo synaptic connectivity. The presence of ganglia-derived factors in the culture medium was required for the in vitro reestablishment of the appropriate in vivo-like connectivity, by reducing the occurrence of electrical connections and promoting the formation of chemical excitatory synapses, while apparently not influencing the formation of inhibitory connections. These heat-labile factors modulated electrical and chemical synaptogenesis through distinct protein tyrosine kinase signal transduction pathways. Taking advantage of in vitro-reconstructed synapses, we have found that feeding interneuron-efferent neuron synapses and mechanosensory neuron-withdrawal interneuron synapses display multiple forms of short-term enhancement-like facilitation, augmentation and posttetanic potentiation as well as homosynaptic depression. These forms of plasticity are thought to be relevant in the regulation of Helix feeding and withdrawal behaviors by inducing dramatic activity-dependent changes in the strength of input and output synapses of high-order interneurons with a crucial role in the control of Helix behavioral hierarchy.

Immunocytochemical evidence that collision sensing neurons in the locust visual system contain acetylcholine.

The lobula giant movement detector (LGMD1 and -2) neurons in the locust visual system are parts of motion-sensitive pathways that detect objects approaching on a collision course. The dendritic processes of the LGMD1 and -2 in the lobula are localised to discrete regions, allowing the dendrites of each neuron to be distinguished uniquely. As was described previously for the LGMD1, the afferent processes onto the LGMD2 synapse directly with each other, and these synapses are immediately adjacent to their outputs onto the LGMD2. Here we present immunocytochemical evidence, using antibodies against choline-protein conjugates and a polyclonal antiserum against choline acetyltransferase (ChAT; Chemicon Ab 143), that the LGMD1 and -2 and the retinotopic units presynaptic to them contain acetylcholine (ACh). It is proposed that these retinotopic units excite the LGMD1 or -2 but inhibit each other. It is well established that ACh has both excitatory and inhibitory effects and may provide the substrate for a critical race in the LGMD1 or -2, between excitation caused by edges moving out over successive photoreceptors, and inhibition spreading laterally resulting in the selective response to objects approaching on a collision course. In the optic lobe, ACh was also found to be localised in discrete layers of the medulla and in the outer chiasm between the lamina and medulla. In the brain, the antennal lobes contained neurons that reacted positively for ACh. Silver- or haematoxylin and eosin-stained sections through the optic lobe confirmed the identities of the positively immunostained neurons.

Gold toning preserves integrity of silver enhanced immunogold particles during osmium tetroxide treatment for demonstration of a biogenic amine.

We describe a protocol that enhances immunolabelling of nervous tissue for ultrastructural study. Insect tissue is fixed, sectioned, and labelled with a polyclonal antiserum against serotonin and a secondary antibody conjugated with 1 nm colloidal gold. The gold particles are silver-enhanced to ease detection and then protected by gold toning. Finally, the tissue is post fixed in glutaraldehyde fixative followed by osmium tetroxide and further processed for electron microscopy. We demonstrated on insect nervous tissue that gold toning protects marker particles from the influence of osmium tetroxide. Use of buffered solutions throughout the protocol led to well preserved ultrastructural details, and marker particle size was not reduced with a short gold toning time. We also suggest use of this protocol for vertebrate or other invertebrate tissue.

Cytochemical evidence that acetylcholine is a neurotransmitter of neurons that make excitatory and inhibitory outputs in the locust ocellar visual system.

Three different cytochemical methods were used to detect acetylcholine in large, second-order neurons of locust ocelli (L-neurons). The first method used polyclonal antibodies raised against choline cleaved from acetylcholine and then conjugated with native protein, and this revealed strong staining for acetylcholine in axons whose number, size, and location indicated that they were of L-neurons. A corresponding staining pattern was found using the second method with a polyclonal antiserum against choline acetyltransferase (ChAT). The third method was the histochemical detection at the electron microscope level of acetylcholinesterase, the enzyme responsible for the breakdown of acetylcholine. We found that this enzyme is located in synaptic clefts of L-neurons in both of the brain regions where L-neurons are known to make excitatory and inhibitory output synapses. Acetylcholinesterase was confined to synaptic sites, which is consistent with a role in synaptic transmission at these synapses. Taken together, the findings suggest that L-neurons use acetylcholine as a neurotransmitter.

Serotonin-immunoreactive neurones in the visual system of the praying mantis: an immunohistochemical, confocal laser scanning and electron microscopic study.

The distribution, number, and morphology of serotonin-immunoreactive (5-HTi) neurones in the optic lobe of the praying mantis Tenodera sinensis were studied using conventional microscopy and confocal laser scanning microscopy. Five or six 5-HTi neurones connect the lobula complex with the medulla, and at least 50 5-HTi neurones appear to be confined to the medulla. In addition, a few large 5-HTi processes from the protocerebrum supply the lobula complex, and two large 5-HTi processes from the protocerebrum ramify in the medulla and lamina, where they show wide field arborisations. In order to provide a basis for understanding the action of serotonin in the lamina, the ultrastructure of its 5-HTi terminals was examined by conventional and immunohistochemical electron microscopy. The 5-HTi profiles were filled with dense core vesicles and made synapses. Output synapses from 5-HTi profiles outnumbered inputs by about 3 to 1. The terminals of the 5-HTi neurones were in close contact with cells of various types, including large monopolar cells, but close apposition to photoreceptor terminals was rare, and no synapses were found between 5-HTi terminals and photoreceptor terminals.

Diagnostic reliability of dermoscopic criteria for detecting malignant melanoma.

BACKGROUND: Recently a new standardized terminology in dermoscopy has been provided by a Consensus Meeting held by the Committee on Analytical Morphology of the Arbeitsgemeinschaft Dermatologische Forschung in Hamburg in order to be applied to further studies in this field. OBJECTIVE: In this study on 159 pigmented skin tumors including 65 melanomas, the validity of various dermoscopic criteria proposed by the Consensus Meeting for detecting melanoma was evaluated. METHODS: In each lesion, a detailed clinical and dermoscopic examination, photographic documentation of the clinical and dermoscopic appearance, surgical excision and histopathologic evaluation were performed. Statistical analyses including chi 2 statistics, logistic regression analysis and CART (classification and regression tree) analysis were applied. RESULTS: The diagnosis of melanoma using dermoscopy could be obtained easily, if combinations of the following criteria were observed: whitish veil, pigment network alterations (e.g. irregular pigment network, narrow pigment network, broad pigment network), irregular extensions, black dots and gray-blue areas. Interestingly, however, clinical and dermoscopic examination to detect melanomas yielded the same results, namely a sensitivity of 94%. The combined use of both methods led to an increase in the diagnostic sensitivity of 95%, whereas the combination of clinical and dermoscopic examination with logistic regression analysis of dermoscopic criteria enabled us to detect all 65 melanomas in our data set, thus providing a sensitivity of 100%. Furthermore, an algorithm for the classification of melanoma based on the evaluation of dermoscopic criteria has been constructed by CART analysis showing that the presence of a whitish veil in combination with a pigment network inevitably indicates melanoma. CONCLUSION: The validity of the various dermoscopic criteria set forth by the Consensus Meeting could be demonstrated as some criteria (e.g. whitish veil, irregular pigment network, irregular extensions) were observed with a significant higher frequency in melanomas.

Nodular focal fatty infiltration of the liver in acquired porphyria cutanea tarda.

A case is reported of acquired porphyria cutanea tarda (PCT) due to administered valproate acid in an epileptic patient. Sonography (US) and computed tomography (CT) showed multiple nodular, well-defined lesions of the liver. Biopsy confirmed the diagnosis of focal fatty infiltration and revealed additionally the signs of hepatic involvement in PCT. Focal fatty infiltration should be considered in patients with multiple liver lesions if there is a predisposing condition. PCT can be a further cause of this type of infiltration.

Morphometric diagnosis of melanocytic skin tumors.

Checking consecutively sampled routine sections of 206 melanocytic lesions with a maximum vertical diameter of at least 1 mm (133 benign dermal nevi, 20 Spitz's nevi, 53 primary malignant melanomas), we measured the morphometric features of at least 60 nuclei each from the superficial and the deep dermal tumor portion using a computer-assisted interactive image analysis system. Furthermore we calculated the so-called maturation parameter (MP) in each case as the ratio of the mean nuclear area in the deep portion and the superficial portion. When we compared the results with those obtained in a training set, we found that the lowest evidence for the discrimination of benign and malignant melanocytic lesions resulted from the application of the mean values of the nuclear area in the superficial layer (efficiency = 62.1%). The efficiency was higher when we used the mean values of the nuclear area in the deep layer (96.1%) and the maturation parameter (85.4%). By applying the mean nuclear area in the deep portion and the maturation parameter simultaneously, we gained the highest efficiency, specificity, and sensitivity for the distinction between benign dermal nevi and malignant melanomas (0.968, 0.955, 1) as well as for the distinction between Spitz's nevi and malignant melanomas (0.986, 0.950, 1). Our study shows that morphometry provides reliable diagnostic results in routinely sampled melanocytic skin tumors.