Hippocampus retains the periodicity of gamma stimulation in vivo

Several behavioral state dependent oscillatory rhythms have been identified in the brain. Of these neuronal rhythms, gamma (20-70 Hz) oscillations are prominent in the activated brain and are associated with various behavioral functions ranging from sensory binding to memory. Hippocampal gamma oscillations represent a widely studied band of frequencies co-occurring with information acquisition. However, induction of specific gamma frequencies within the hippocampal neuronal network has not been satisfactorily established. Using both in vivo intracellular and extracellular recordings from anesthetized rats, we show that hippocampal CA1 pyramidal cells can discharge at frequencies determined by the preceding gamma stimulation, provided that the gamma is introduced in theta cycles, as occurs in vivo. The dynamic short-term alterations in the oscillatory discharge described in this paper may serve as a coding mechanism in cortical neuronal networks.     

Differences in motility pattern between human buccal fibroblasts and periodontal and skin fibroblasts

Migration of fibroblasts from surrounding normal tissue into the wound bed is an important requirement for successful wound healing. This study investigated the motility pattern of buccal, periodontal and skin fibroblasts to determine whether differences in the wound healing efficiency at these sites can be explained by differences in the motile behavior of their respective fibroblast populations. The migratory characteristics were studied in a two-dimensional culture system. The migration of single cells was time-lapse video recorded at intervals of 15 min for a period of 6 h using a computer-assisted microscope work-station. For evaluation of cell morphology, cell contours were recognized semiautomatically and used for determination of cell area, cell spreading and number and length of processes. We found that the cellular displacement of the buccal fibroblasts was only approximately 50% of the cellular displacement of periodontal and skin fibroblasts. The decreased cellular displacement of the buccal fibroblasts was found to be due to both lower cellular speed and less persistence in direction. The buccal fibroblasts also displayed smaller areas and longer processes. The differences in cellular morphology and motility pattern amongst the three fibroblast types could not be explained by differences in secretion of extracellular matrix components and are therefore believed to reflect phenotypic differences amongst fibroblast subpopulations.     

Development and evaluation of an ELISA for human trefoil factor 3

BACKGROUND: The three trefoil factors (TFF1, TFF2, and TFF3) are small peptides believed to cross-link mucous glycoproteins and to play a role in the maintenance and repair of the gastrointestinal mucosa. To define the physiologic and potential diagnostic values of TFF3, assays able to measure TFF3 are warranted. METHODS: An ELISA was developed that uses two antibodies from rabbits immunized with recombinant human TFF3 and a calibrator (3-100 pmol/L) prepared from recombinant human TFF3. RESULTS: The ELISA had a detection limit of 3.0 pmol/L. The imprecision (CV) was 5-9% for mean concentrations of 13-65 pmol/L, corresponding to serum concentrations of 65-330 pmol/L. There was no cross-reaction toward human TFF1 and TFF2 (40 nmol/L). Neither food intake nor the menstrual cycle influenced the values of TFF3 significantly. The central 95% reference interval for TFF3 in serum from healthy blood donors (n = 300) was 91-250 pmol/L and showed no variation with age and limited variation with sex. TFF3 was increased in serum from patients (n = 12) with inflammation and/or ulceration of the upper gastrointestinal tract (P <0.05), whereas in serial measurements of serum from three patients with severe exacerbation of chronic inflammatory bowel disease restricted to the colon, normal concentrations and only minor variations during treatment and tapering were observed. CONCLUSIONS: The ELISA measures TFF3 in human serum and represents a specific and precise method for measurement of TFF3, which will be of value for further studies of TFF3 in health and disease.     

Prolonged low-dose dexamethasone, in early gestation, has no long-term deleterious effect on normal ovine fetuses

Low-dose dexamethasone (D) treatment is used in pregnancies where the fetus is suspected to be at risk of congenital/virilizing adrenal hyperplasia. To study if this treatment had any immediate or long-term effects in normal fetuses, pregnant ewes were treated with D (20 microg/kg maternal body weight x d) or saline (S), from d 25-45 of gestation. Tissue was collected from fetuses killed at 45 d (S = 6; D = 8), 130 d (S = 8; D = 8), or lambs at 2 months of age (S = 6; D = 6) and mRNA levels measured using real-time PCR. D treatment reduced adrenal wt at 45 d (S, 12.2 +/- 0.7 mg; D, 6.3 +/- 0.4 mg) and significantly decreased adrenal mRNA for P(450scc). At 130 d, fetuses from the D treatment were growth retarded (S, 3.2 +/- 0.1 kg; D, 2.5 +/- 0.1 g), but the adrenals were appropriate for the body weight. mRNA levels of angiotensinogen, the AT(1) receptor and mineralocorticoid receptor (MR) and GR were similar in kidney and brain (hypothalamus, hippocampus, medulla oblongata) except for hippocampal expression of MR and GR, which was significantly decreased by D treatment. By 2 months, BW and hippocampal MR and GR mRNA levels were similar, and lambs were normotensive (S, 83 +/- 3 mm Hg; D, 78 +/- 3 mm Hg). Thus, there were no persistent, long-term effects of prolonged low-dose D treatment in normal ovine fetuses.     

Septisches Krankheitsbild bei einer 33-jährigen Patientin

Zusammenfassung Eine 33-j?hrige Patientin wurde mit dem Bild eines septischen Schocks, disseminierter intravasaler Gerinnung und beginnendem Multiorganversagen eingeliefert. Das Auftreten der ersten Symptome w?hrend der Mens-truation und der Tampongebrauch lenkten den Verdacht auf ein Toxic Shock Syndrome. Das TSS ist ein septisches Krankheitsbild, das durch einen exotoxinproduzierenden Staphylococcus-aureus-Stamm verursacht wird. Zur Diagnose müssen 5 Kriterien erfüllt sein. Im Cervix-uteri-Abstrich gelingt der Nachweis von Staphylococcus aureus und Toxic-Shock-Syndrome-Toxin-1. Die Therapie umfasst die Gabe von Clindamycin sowie in schweren F?llen die Gabe von Immunglobulinen. Die Inzidenz des TSS liegt bei 1,0 auf 100.000 Frauen zwischen 15-44 Jahren, mit einer Letalit?t von 3,5%. Ungef?hr 60% der TSS-F?lle sind menstruationsassoziiert. Differenzialdiagnostisch ist v. a. an Infektionen mit Gruppe-A-Streptokokken zu denken.