The effect of elevated intracranial pressure on the vibrational response of the ovine head

Although potentially fatal increases in intracranial pressure (ICP) can occur in a number of pathological conditions, there is no reliable and noninvasive procedure to detect ICP elevation and quantitatively monitor changes over time. In this experimental study, the relationships between ICP elevation and the vibrational response of the head were determined. An ovine animal model was employed in which incremental increases in ICP were elicited and directly measured through intraventricular cannulae. At each ICP increment, a vibration source elicited a flexural response of the animal's head that was measured at four locations on the skull using accelerometers. Spectral analysis of the responses showed changes in proportion to ICP change up to roughly 20 cm H₂O (15 mm Hg) above normal; a clinically significant range. Both magnitude and phase changes at frequencies between 4 and 7 kHz correlated well (γ>0.92) with ICP across the study group. These findings suggest that the vibrational response of the head can be used to monitor changes in ICP noninvasively.     

Biochemistry of antral ulcer in patients

Separation and measurement of adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP), adenine-adenosine, lipid phosphates (lipid-P), RNA and DNA, furthermore, separation of Mg2+-dependent, total (Mg2+-dependent plus Na+--K+-dependent or Mg2+--Na+--K+-dependent) and Na+--K+-dependent ATPases and measured of their activities were carried out in tissue samples obtained from "ulcerated antral mucosa", from "non-ulcerated antral mucosa" and the muscular layer beneath the examined mucosa specimens, of patients with antral ulcer. It has been found that (1) the tissue levels of ATP, ADP and AMP, of the sum ATP + ADP + AMP, adenine-adenosine, lipid-P, RNA all calculated for 1.0 mg DNA content, further, the activities of Mg2+-dependent, total (Mg2+-dependent plus Na+--K+-dependent) and Na+--K+-dependent ATPase were significantly higher in the ulcerated antral mucosa than those in the control antral mucosa; (2) no significant biochemical alterations were found in the muscles under the ulcerated and non-ulcerated antral mucosa of patients with antral ulcer; (3) the extents of increases in the substrate levels of ulcerated antral mucosa depended on their original levels in the control antral mucosa. The results indicate a cellular hyperfunction in the ulcerated antral mucosa, in comparison with the control one. No circulatory injury could be demonstrated in the ulcerated antral mucosa.     

A second field metachronous Merkel cell carcinoma of the lip and the palatine tonsil confirmed by microarray-based comparative genomic hybridisation

Merkel cell carcinoma was diagnosed in a 79-year-old Caucasian woman. The tumour was localised to the upper lip and was in stage T2. After successful cryosurgery and a 7-year tumour-free period, a new tumour developed in her palatine tonsil. Histologically and immunohistochemically, this resembled the tumour in the lip. The regional lymph nodes were devoid of metastasis. The paraffin-embedded material of the two tumours and the unaffected lymphatic tissue were analysed with DNA microarrays for comparative genomic hybridisation to assess the genetic relationship of the tumours. In both tumours, regions on 2p and 10p were commonly over-represented, while 41 regions on chromosomes 1–4, 6, 8–9, 11 and 14–22 were commonly under-represented. Chromosomes 1, 3, 4, 16–18 and X were most frequently involved in the DNA losses. In gene copy numbers in the two tumours, 31 chromosome locations were found to be differently affected. The partly similar and partly different molecular patterns indicated a genetic relationship between the tumours and excluded the possibility that the tonsillar tumour was a metastasis. The findings suggest that a genetically altered field was the reason for the development of the tonsillar cancer; thus, it can be regarded pathogenetically as a second field tumour.     

Phantoms for texture analysis of MR images. Long-term and multi-center study

The application of texture analysis (TA) in magnetic resonance imaging (MRI) requires the availability of texture phantoms for use in the standardization of in vivo measurements. The aims of our study were (a) to develop a new type of phantoms suitable for MRI and TA and test their long-term stability; (b) to optimize the choice of texture parameters describing the phantoms; (c) to compare different MR imagers according to texture parameters in a multi-center study. A long-term study performed at 4.7 T proved that the developed phantom based on polystyrene spheres and an agar gel solution is stable at least 12 months. This phantom, with nodular patterns, was found useful for the modeling of structural differences. The comparison of TA parameters at 4.7 and 7 T proved that the same parameters can be used for the separation of structures. The proposed algorithm of the selection of TA parameters shows that there exists a part of texture parameters which can be measured with high reproducibility (1-3%); on the other hand, their absolute values can differ by more than 30% if the textures differ. Results obtained from the multi-center study of whole body MR imagers show the wide variation in the misclassification rates at the different sites and point out the importance of the set up of MR sequences.     

Production and Characterization of Generic Antibodies Against s-Triazine and Sulfonylurea Herbicides

Two different hapten designs have been suggested for production of generic antibodies. The first approach was based on the immunogen prepared by conjugating simazine mimic to carrier proteins through the Cl position of the s-triazine herbicide. For sulfonylurea herbicides a single ring hapten strategy was designed in order to produce antibodies with dominant selectivity towards arylsulfonyl or triazine moieties of metsulfuron-methyl. The best monoclonal antibody raised against simazine-derived hapten mimic (clone B10/B8/D2) exhibited in direct ELISA a broad pattern for a group of methylthio and methoxy s-triazines. Cross-reactivities based on simazine ( = 100%) were 417, 125, 25, 50, 28, 42 and 11% for simetryn, ametryn, prometryn, terbutryn, aziprotryn, atraton and atrazine, respectively. The superiour generic pattern was found for monoclonal antibody raised against s-triazine moiety of metsulfuron-methyl herbicide (clone 2C8/C8). This antibody showed in indirect ELISA the cross-reactivity values 100, 142, 95, 60, 40, 167, 83 and 21% for metsulfuronmethyl, cinosulfuron, triasulfuron, primisulfuron-methyl, thifensulfuron-methyl, chlorsulfuron and prosulfuron and tribenuron-methyl, respectively. The assays using both monoclonal and polyclonal antibodies operated within the ppt-ppb calibration ranges.     

Inflammatory mediators convert anandamide into a potent activator of the vanilloid type 1 transient receptor potential receptor in nociceptive primary sensory neurons

The endogenous ligand, anandamide activates at least two receptors on nociceptors; the excitatory vanilloid type 1 transient receptor potential receptor, the activity of which is indispensable for the development and maintenance of inflammatory heat hyperalgesia, and the inhibitory cannabinoid 1 receptor, the activity of which reduces that pathological pain sensation. Recent data are equivocal on whether increasing anandamide levels at the peripheral terminals of nociceptors in pathological conditions increases or decreases inflammatory heat hyperalgesia. Here, by using the cobalt-uptake technique we examined whether vanilloid type 1 transient receptor potential receptor activity evoked by 10 nM-100 microM anandamide is increased or decreased in inflammatory conditions. An inflammatory milieu for cultured rat primary sensory neurons was established by incubating the cells in the presence of the inflammatory mediators, bradykinin and prostaglandin E2. Anandamide, similarly to the archetypical vanilloid type 1 transient receptor potential receptor agonist, capsaicin induced concentration-dependent cobalt-uptake in a proportion of neurons. However, the potency of anandamide was significantly lower than that of capsaicin. While pre-incubation of cultures with bradykinin and prostaglandin E2 alone did not evoke cobalt-entry, the inflammatory mediators potentiated the effect of both capsaicin and anandamide. Application of the competitive vanilloid type 1 transient receptor potential receptor antagonist, capsazepine, or inhibitors of protein kinase A, protein kinase C or phospholipase C inhibited the anandamide-evoked cobalt-uptake both in the presence and absence of bradykinin and prostaglandin E2. These findings show that inflammatory mediators significantly increase the excitatory potency and efficacy of anandamide on vanilloid type 1 transient receptor potential receptor, thus, increasing the anandamide concentration in, or around the peripheral terminals of nociceptors might rather evoke than decrease inflammatory heat hyperalgesia.     

Intracellular signalling and cytoskeletal rearrangement involved in Yersinia pestis plasminogen activator (Pla) mediated HeLa cell invasion

Yersinia pestis, the etiologic agent of plague is a highly invasive organism being able to invade non-phagocytic epithelial cells. Its plasminogen activator (Pla), encoded by the pPCP1 plasmid plays a pivotal role in internalisation of bacteria by HeLa cells. The aim of this study was to analyse the intracellular signalling processes and cytoskeletal rearrangement events associated with invasion. Wortmannin caused a 50% decrease of invasiveness at 50nM concentration pointing to the involvement of phosphatidyl-inosinol-4 kinase (PtINs4). Pre-treatment with staurosporin, a potent inhibitor of protein kinases (PKs) and with genistein, a specific tyrosine kinase inhibitor decreased the number of internalised bacteria about seven-fold and two-fold, respectively, indicating the involvement of PKs including tyrosine kinases in Pla-mediated internalisation. Cytochalasin D, an actin polymerisation inhibitor, C3 exoenzyme of Clostridium botulinum, a specific inhibitor of small GTPase Rho, and NDGA, a 5-lipoxygenase inhibitor also involved in Rho activation strongly reduced the number of internalised bacteria revealing the role of cytoskeletal events in the invasion process. All the tested inhibitors changed the invasion but not the adhesion pattern of the Pla producing recombinant strain. Actin rearrangement could also be visualised also with rhodamin-phalloidin staining.     

The nucleus basalis magnocellularis: The origin of a cholinergic projection to the neocortex of the rat

The cells of origin of a neocortical cholinergic afferent projection have been identified by anterograde and retrograde methods in the rat. Horseradish peroxidase injected into neocortex labelled large, acetylcholinesterase-rich neurons in the ventromedial extremity of the globus pallidus. This same group of neurons underwent retrograde degeneration following cortical ablations. The region in which cell depletion occurred also showed significant decreases in the activities of choline acetyltransferase and acetylcholinesterase. Discrete electrolytic and kainic acid lesions restricted to the medial part of the globus pallidus each resulted in significant depletions of neocortical choline acetyltransferase and acetylcholinesterase. Hemitransections caudal to this cell group did not result in such depletions. Taken together these observations suggest that the acetylcholinesterase-rich neurons lying in the ventromedial extremity of the globus pallidus, as mapped in this study, constitute the origin of a major subcortical cholinergic projection to the neocortex. The utility of acetylcholinesterase histochemistry in animals pretreated with di-isopropylphosphorofluoridate in identifying cholinergic neurons is discussed in the light of this example; specifically, it is proposed that high acetylcholinesterase activity 4–8 h after this pretreatment is a necessary, but not sufficient, criterion for the identification of cholinergic perikarya.The neurons in question appear to be homologous to the nucleus basalis of the substantia innominata of primates, and are thus termed ‘nucleus basalis magnocellularis’ in the rat. No evidence was obtained to support the hypothesis that nucleus of the diagonal band projects to neocortex. However, striking similarities in size and acetylcholinesterase activity were observed among the putative cholinergic perikarya of the nucleus basalis magnocellularis, the nucleus of the diagonal band, and the medial septal nucleus.Kainic acid lesions of the neocortex produced uniform and complete destruction of neuronal perikarya. These lesions decreased neocortical glutamic acid decar?ylase activity, suggesting that there are GABAergic perikarya in the neocortex. However, the same lesions did not affect neocortical choline acetyltransferase. This observation suggests that there are no cholinergic perikarya in the neocortex, a conclusion that is consistent with the absence of intensely acetylcholinesterase-reactive neurons in the neocortex.     

Plateau potentials and membrane oscillations in parasympathetic preganglionic neurones and intermediolateral neurones in the rat lumbosacral spinal cord

Whole-cell patch recordings were made from parasympathetic preganglionic neurones (P-PGNs) and unidentified intermediolateral (IML) neurones in thick slices of the lower lumbar and sacral spinal cord of 14- to 21-day-old rats. The P-PGNs and IML neurones examined were similar in terms of soma sizes, input resistance and capacitance, and displayed a sag conductance as well as rebound firing. In the absence of drugs, the neurones responded with either tonic or adapting firing to depolarizing current steps. However, in the presence of the group I metabotropic glutamate receptor agonist ( RS )-3,5-dihydroxyphenylglycine (DHPG), almost half of the neurones displayed accelerating firing rates during the constant current injection, followed by a sustained after-discharge. In the presence of TTX, plateau potentials were observed. The firing changes and plateaux were blocked by nifedipine, an L-type Ca²⁺ channel blocker, and ( S )-(−)-Bay K8644 was able to produce these firing changes and plateaux in the absence of DHPG, demonstrating the involvement of an L-type Ca²⁺ conductance. Ca²⁺-activated nonspecific cationic conductances also appear to contribute to the firing changes. A few neurones displayed membrane oscillations and burst firing in the presence of DHPG. The results suggest that the firing characteristics of both P-PGNs and other neurones likely to be involved in caudal spinal reflex control are not static but, rather, quite dynamic and under metabotropic glutamate receptor modulatory control. Such changes in firing patterns may be involved in normal pelvic parasympathetic reflex function during micturition, defaecation and sexual reflexes, and may contribute to the abnormal output patterns seen with loss of descending brainstem input and visceral or perineal sensory disturbances.     

Relationship between X-inactivation and clinical involvement in Fabry heterozygotes. Eleven novel mutations in the α-galactosidase A gene in the Czech and Slovak population

We have identified 21 different -galactosidase A gene (GLA) mutations in 22 unrelated Czech and Slovak families with Fabry disease. Eleven of these mutations were novel (point mutations D93N, A135V, D155H, G171R, Q280K, G360S, Q330X, splicing errors c.194ins14, c.801ins36 and deletions c.674_732del59, g.3405_6021del2617). Genotyping of family members for family-specific mutations revealed 55 heterozygotes that manifested clinical symptoms of different severity. To examine the contribution of X-inactivation skewing to disease manifestation in Fabry heterozygotes, we have adopted the Mainz severity scoring scheme and compared the score values with the X-inactivation status in 39 carriers in an age-dependent manner. The age-score trendline of Fabry females who had a predominantly inactivated X-chromosome bearing a wild-type GLA allele (10 of 38 females) was markedly steeper than in the rest of the cohort. One female carrier with an inactivated mutated allele had a low score value when compared to the other heterozygotes of the same age. These data suggest that X-inactivation is indeed a major factor determining the severity of clinical involvement in Fabry heterozygotes. There was a statistically significant difference between the severity score values of heterozygotes with random and non-random X-chromosome inactivation at the 5% level of significance. Further studies will show if the degree of the wildtype allele inactivation will be useful as a predictive marker of severity of phenotype in Fabry heterozygotes. Although the correlation between X-inactivation skewing and presentation of the disease in Fabry heterozygotes has previously been suggested in the literature, this report is among the first attempts to examine this relationship systematically.