Glycoprotein Enrichment Analytical Techniques: Advantages and Disadvantages.

Protein glycosylation is one of the most important posttranslational modifications. Numerous biological functions are related to protein glycosylation. However, analytical challenges remain in the glycoprotein analysis. To overcome the challenges associated with glycoprotein analysis, many analytical techniques were developed in recent years. Enrichment methods were used to improve the sensitivity of detection, while HPLC and mass spectrometry methods were developed to facilitate the separation of glycopeptides/proteins and enhance detection, respectively. Fragmentation techniques applied in modern mass spectrometers allow the structural interpretation of glycopeptides/proteins, while automated software tools started replacing manual processing to improve the reliability and throughput of the analysis. In this chapter, the current methodologies of glycoprotein analysis were discussed. Multiple analytical techniques are compared, and advantages and disadvantages of each technique are highlighted.

[Selective vulnerability of neuronal injury after experimental heart arrest]. / Selektívna zranitel'nost neurónov po experimentálnom zastavení srdca.

The study was aimed at the analysis of vulnerability of the olfactory bulb neurons in dogs after experimental heart arrest lasting for 15 minutes and recirculation lasting for 1 hour. By means of the Nauta degenerative neurohistologic method the reactions of individual types of nerve cells in the olfactory bulb were investigated. Nauta-positive granules were observed in the cytoplasm of the mitral and tufted cells of the olfactory bulb, which are of dopaminergic character. The granulations were present in the cellular areas which are rich in Nissl substance. The granular and short-axon cells of GABA-ergic character which contain a small amount of Nissl granules lack the Nauta-positive granules. Similarly, the Nauta-positive granules were absent in the axon hillock of mitral cells which under normal conditions do not contain the Nissl substance. These results justify the conclusion that ischemia lasting for 15 minutes and one-hour recirculation primarily affect the excitatory neurons rich in the Nissl substance. (Fig. 4, Ref. 16.).

Unusual type of ischemically induced synaptic degeneration studied by Hicks method.

This study describes the degenerating axonal termination and filamentous synaptic degeneration after 30 minutes spinal cord ischemia followed by 3 days survival using Hicks neurofibrillar impregnation. From laminoarchitectonic point of view a clear evidence was gained supporting the original description obtained by Nauta method. The majority of degenerated boutons revealed by Hicks method was found in the deep layers of the dorsal horn and then with increasing density in the intermediate zone and partly in the neuropil of the anterior horn. These results confirm the ability of Hicks method as a reliable tool in systematic research of the ischemically damaged synaptic contacts.

A new applicability of the suppressive Nauta method in the early phase of neuronal damage.

A new applicability of the suppressive Nauta impregnation method was tested allowing the detailed mapping of early neuronal damage expressed in the form of somatodendritic argyrophilia. Two spinal cord ischemia-reperfusion models of rabbit and dog, a model of canine global brain ischemia-reperfusion, involving cardiac arrest followed by resuscitation, and a canine spinal cord compression-decompression model were used. Early phases of neuronal damage are characterized by conspicuous somatodendritic argyrophilia permitting an exact evaluation of acute neuronal damage according to soma size, dendritic ramifications and localization of the affected neuronal neuronal pool. By its high sensitivity to somatodendritic damage the suppressive Nauta method appears to be a valuable neuropathological technique.

Mapping of the canine lumbosacral spinal cord neurons by Nauta method at the end of the early phase of paraplegia induced by ischemia and reperfusion.

The Nauta impregnation method was used to map the neuronal changes in the canine lumbosacral segments following ischemia and reperfusion. The early perikaryal changes ensuing during the first phase after 30 min of thoracic aorta cross-clamping alone or followed by 30 min of reperfusion were mapped. During the second phase (one to six postischemic reperfusion days) the dendritic, preterminal and synaptic degeneration developed. The influence of 30 min cross-clamping immediately followed by perfusion fixation is characterized by the occurrence of flocculent argyrophilic clusters in the cytoplasm of middle-sized and large neurons of L3-S1 segments. Declamping of the thoracic aorta followed by 30 min of reperfusion basically modifies the susceptibility of lumbosacral neurons to Nauta impregnation promoting somatic and dendritic argyrophilia mainly of small (less than 15 microns) neurons, localized mostly in the fifth, sixth and seventh layers, respectively. This early appearing somatic and dendritic argyrophilia is not abolished by a pretreatment of sections with acetone in which cholesterol and its esters are highly soluble, or chloroform-methanol which extracts total lipid. After 24 h of reperfusion the somatic and dendritic argyrophilia is lost but the first signs of drop-like degeneration are detected in all but three superficial dorsal horn layers. At the end of the third reperfusion day, an atypical form of bouton degeneration was found, consisting of massive occurrence of enlarged (greater than 4 microns) boutons encircled by a clear halo. Laminar distribution of enlarged degenerating boutons coincides with laminar quantitative distribution of small argyrophilic neurons detected 30 min after reperfusion. The basic orientation of the many terminal fibres attached to enlarged boutons suggests that they belong to the axons localized mainly in the lateral and anterior columns. Despite a dense argyrophilic network pervading the gray matter of lumbosacral segments only pale shadows of middle-sized and large neurons were found at the end of the sixth reperfusion day and neither somatic nor vessel wall argyrophilia could be detected. All animals surviving one, three and six days postoperatively suffered from fully developed paraplegia.

Government relations. Identifying the issues, delivering the message.

Out of the multitude of federal and state bills that relate to health care, the government relations council must sort, interpret and track those bills which will impact the hospital and the health care industry.

Adolescent growth in weight and its relation to menarche in contemporary American girls.

Weight measurements at frequent intervals, from age six to adulthood, of 248 contemporary middle-class American girls were fitted to a mathematical model (Preece and Baines 1978). The results are used to examine weight and weight velocity at specified ages, the characteristics of the weight growth spurt and the relation of this spurt to menarche. These statistics are compared with previously complied height statistics for the same girls. Although the data of all 248 girls were readily fitted, no usable spurt take-off ages were found for 41 girls. Calculations, therefore, were made separately for two subsets: principal subset A (207) and variant subset B (41). The values (subset A) for weight at specified ages and at critical points of the adolescent growth spurt agree well with comparable US and Western European data. Comparing weight spurt (subset A) with height spurt, the weight spurt takes off earlier, peaks and ends later; adult weight is reached much later. The Preece-Baines model lacks a component for analysing the mid-growth spurt. Therefore, for some children, the model makes a too-early estimate of age at adolescent spurt take-off (and other dependent variables). This may account for the unrealistic take-off ages of girls in subset B, although these girls are also significantly younger and lighter than subset A girls at spurt peak and are also younger at menarche. While certain differences between the two subsets may be mathematical distortions caused by the Preece-Baines model, others may be real.

Adolescent growth in height and its relation to menarche in contemporary American girls.

Height measurements at frequent intervals, from age six to adulthood, of 338 middle-class American girls are used to examine contemporary height and height velocity at specified ages, the characteristics of the adolescent growth spurt and its relation to menarche. These data, analysed by fitting to a mathematical model (Preece and Baines 1978), are presented as tables of means and standard deviations, percentiles and correlations. There is no evidence of a trend towards increased or accelerated growth in height; in the United States and Western Europe, girls have been the same height at specified ages, and have grown at the same rate, for the past 45 years, at least. Examination of the data plots and the growth statistics of all 338 girls revealed a group of 67 girls (designated E) who are different from the remaining 271 girls (designated S). Plots of the E girls show no discernible growth spurt. Compared with the S girls, they are significantly taller at specified ages; velocities are greater at ages 6 and 9 but less at age 12. During the growth spurt, and at menarche, they are taller but not older. Their adult height is greater and is reached later. Their velocity at takeoff is greater but, at peak, smaller; spurt intensity is much lower. Their adolescent growth spurt contributes less to adult height. For all 338 girls (the E as well as the S subgroup), adult height is correlated only with height during the growth spurt and is virtually independent of spurt timing, whereas menarche is strongly correlated with spurt timing and very little with height. Additional indications that menarche is unrelated to size are that E girls at menarche are significantly taller but not older than the S girls, and that 19 prematurely-born girls at menarche are shorter than girls born at full term but the same age.