Bilateral hippocampal interictal spiking and kindling expression in rabbits

The temporal/spatial dissemination of interictal spikes among different brain structures was studied during the course of kindling to determine if the long-term dissemination pattern reflects the rate and expression of kindling. The experiments were conducted on adult rabbits with chronically implanted electrodes (dorsal hippocampus, amygdala, caudate, all bilateral, sensory motor and occipital cortices). Rabbits (n = 13) were subjected to once daily electrical stimulation in the left hippocampus. Kindling resulted in the development of two different epileptic phenomena: 7 animals quickly (in 2-3 weeks) achieved a fully kindled state, characterized by generalized seizures, whereas the remaining 6 rabbits did not reliably progress beyond partial seizures even after more prolonged stimulation. Animals were accordingly divided into two groups referred to as generalized seizure and partial seizure. The temporal/spatial dissemination pattern, particularly in the two hippocampi, was very different between the groups. In both groups interictal spiking originated in one of the hippocampi independent of site stimulated and represented formation of the primary hippocampal epileptic focus. The generalized seizure group demonstrated stability of the primary hippocampal epileptic focus with permanent predominance of spiking in it over the course of kindling, and a high level of bilateral synchronous hippocampal interictal spiking. In the partial seizure group the primary hippocampal epileptic focus was established during the first 2-3 weeks of stimulation. This was later suppressed upon the development of an independent secondary focus in the opposite hippocampus. These animals also displayed very low levels of synchronous bilateral hippocampal interictal spiking. We suggest that an antagonistic relationship can develop between mirror hippocampal epileptic foci. This can be associated with a low level of bilateral hippocampal synchronous spiking, kindling retardation, and manifestation of partial seizures.     

Hypoglycaemic activity of an HMG-containing flavonoid glucoside, chamaemeloside, from Chamaemelum nobile

The 3-hydroxy-3-methylglutaric acid (HMG) containing flavonoid glucoside chamaemeloside, has been determined to have in vivo hypoglycaemic activity comparable to that of free HMG. An improved isolation scheme for obtaining chamaemeloside from Chamaemelum nobile is presented.     

Hamartoma of the larynx: a critical review of the literature

Though very rare compared to imported malaria, airport malaria should not be disregarded considering its very special gravity often due to late diagnosis. In most cases, it could be avoided if airlines and airports applied disinsecting measures vigilantly.     

Trends in incidence of and mortality from invasive cancer of the uterine cervix in Scotland (1975-1994)

BACKGROUND: Among the victims of floods, earthquakes, and hurricanes, there is an increased prevalence of post-traumatic stress disorder and depression, which are risk factors for suicidal thinking. We conducted this study to determine whether natural disasters affect suicide rates. METHODS: From a list of all the events declared by the U.S. government to be federal disasters between 1982 and 1989, we selected the 377 counties that had each been affected by a single natural disaster during that period. We collected data on suicides during the 36 months before and the 48 months after the disaster and aligned the data around the month of the disaster. Pooled rates were calculated according to the type of disaster. Comparisons were made between the suicide rates before and those after disasters in the affected counties and in the entire United States. RESULTS: Suicide rates increased in the four years after floods by 13.8 percent, from 12.1 to 13.8 per 100,000 (P<0.001), in the two years after hurricanes by 31.0 percent, from 12.0 to 15.7 per 100,000 (P<0.001), and in the first year after earthquakes by 62.9 percent, from 19.2 to 31.3 per 100,000 (P<0.001). The four-year increase of 19.7 percent after earthquakes was not statistically significant. Rates computed in a similar manner for the entire United States were stable. The increases in suicide rates were found for both sexes and for all age groups. The suicide rates did not change significantly after tornadoes or severe storms. CONCLUSIONS: Our study shows that suicide rates increase after severe earthquakes, floods, and hurricanes and confirms the need for mental health support after severe disasters.     

Absence of MEN2A- or 2B-type RET mutations in primary neuroblastoma tumour tissue

A spectroscopic method for thiol analysis, based on the complexation reaction with Pd(II), is described. The proposed method is simple and sensitive and can be used for a rapid analysis of thiols in human lymphocytes.     

Role of intestinal transit in the pathogenesis of gallbladder stones

The aim of the study was to compare the occurrence and levels of A. actinomycetemcomitans, P. gingivalis, and P. intermedia in the subgingival plaque from sites with and without early periodontitis in adolescents using an ELISA. 47, 15- to 16-year-old adolescents (39 Indo-Pakistani, 8 white Caucasian) were examined for clinical attachment level, probing depth, supragingival plaque, subgingival calculus and bleeding on probing on the mesio-buccal and disto-buccal aspects of the 1st molars and the incisors. Based on the clinical data, 2 sites per subject were selected for subgingival plaque sampling 3 weeks later: in 32 subjects with loss of attachment > or = 1 mm, a diseased site (D) and a healthy comparison control site (C) were sampled; in 15 subjects in whom loss of attachment had not yet developed, 1 of the upper molar sites was selected, called the at-risk site (R), together with a C site. The presence and levels of A. actinomycetemcomitans, P. gingivalis, and P. intermedia were determined using an ELISA. The loss of attachment subgroup had significantly more pockets > or = 4 mm, subgingival calculus and bleeding on probing (p < 0.05). Significantly more of the D than C sites had P. gingivalis both at detectable and at measurable levels (p < 0.05). In subjects who had no loss in clinical attachment levels, fewer sampled sites harboured any of the suspected periodontopathogens investigated, and no significant differences were found between the R or C sites (p > 0.05). Although there was a significantly higher prevalence and extent of loss of attachment > or = 1 mm in the Indo-Pakistani subjects compared with the Caucasians (p < 0.05), no differences could be identified in the distribution of the bacteria. It is concluded that monitoring of the subgingival plaque may be useful in studies of early periodontitis in adolescents, and the role of P. gingivalis needs to be elucidated in prospective longitudinal investigations.     

Neonatal piglet model of intraaortic balloon pumping: improved efficacy using echocardiographic timing

Secretoneurin (SN), a 33-amino acid neuropeptide, is derived from secretogranin II that is released from sensory afferent C-fibers by capsaicin. Described functions of secretoneurin include chemotaxis of monocytes and endothelial cells, and inhibition of endothelial cell proliferation. Inhibition of monocyte chemotaxis by staurosporine indicated involvement of specific signaling pathways. We have tested effects of SN, substance P (SP), and interleukin-8 (IL-8) on eosinophil migration in modified Boyden chambers including signaling mechanisms of neuropeptide and cytokine stimulation of human eosinophils. Experiments showed SN as eosinophil chemoattractant comparable in its potency to IL-8. Checkerboard analysis, usage of a specific anti-SN-antibody, and receptor desensitization experiments confirmed the chemotactic activity. Preincubation of the cells with effective concentrations of staurosporine or tyrphostin-23 showed no effect, whereas treatment with wortmannin (WTN) or 3-isobutyl-1-methylxantin (IBMX) completely blocked SN-induced migration. Additionally, experiments ruled out tyrphostin-23- and WTN-sensitive signaling pathways for SP-induced chemotaxis of eosinophils. We conclude that SN-stimulated human eosinophil chemotaxis is mediated via a unique and specific signal transduction pathway that involves activation of phosphodiesterases and WTN-sensitive enzymes, ie, phospholipase D and phosphatidylinositol-3-kinase. In contrast, we report that activation of the latter and tyrosine kinases is required for SP-induced chemotaxis of eosinophils.