Projections of submucous neurons to the myenteric plexus in the guinea pig small intestine

Coronary venous hypertension induced by partial coronary sinus obstruction (CSO) in the dog, prevents or delays the predictable ventricular fibrillation (VF) of the early phase of acute ischemia. Also, CSO acting presumably through enhanced myocardial hydration, normalizes the inhomogenous extracellular potassium ([K+]o) accumulation, a major factor in producing the electrophysiological disparities, characteristic of arrhythmogenic substrate. To further clarify the mechanism of early ischemic VF prevention in dogs, radioactive microspheres were used to evaluate regional perfusion changes, resulting from CSO sufficient to raise the coronary sinus pressure to 40 mmHg, before and during ischemia induced by double coronary artery occlusion (CAO) (n=5). Also, global or regional unipolar electrogram mapping was used to assess changes of epicardial ventricular activation times (AT) and sequence and activation recovery intervals (ARI) during CSO, CAO and combined CSO and CAO, induced in random order (n=8). CSO did not affect regional perfusion nor improved collateral blood flow during ischemia. With CSO, AT shortened modestly over time (0.41+/-1.1 ms/min, r=0.85, P<0. 05) and ARI transiently decreased by up to 5.5%. With CAO, AT became variably delayed and isochrone map distortions were indicative of localized conduction delays or blocks, consistent with elevated [K+]o. In contrast, when CAO was preceded by CSO, AT delays were homogenous and normal activation sequence was preserved. Also, whereas with CAO, ARI shortened unequally over the ischemic region by as much as 43% at individual sites (average of 38.3+/-6.8 ms, P<0. 001), with combined CSO and CAO, ARI shortening was less pronounced and more homogenous (26.1+/-5.6 ms, P<0.05), not exceeding 29% at any site. Thus, in accordance with previous findings of enhanced [K+]o homogeneity, coronary venous hypertension reduces the disparities of activation and refractoriness of ischemia attributable, at least in part, to disparate [K+]o accumulation. Since no collateral blood flow improvement could be identified, the salutary electrophysiological effects of CSO may reflect a more homogenous extracellular environment, due to preservation of normal microvascular pressure (Pmv) and sustained filtration and lymph flow.     

Cloning and characterization of a novel upstream untranslated exon of the mouse Fgf-1 gene

Several recent studies have reported that there is an imbalance of increased oxidant status and decreased antioxidant system in women with preeclampsia and that factor might contribute to the pathogenesis of the disease. The following study examined blood levels of some of the antioxidants (glutathione, glutathione-peroxidase and -SH groups) as markers of lipid peroxidation in women with preeclampsia compared with normal gestation. Blood levels of these antioxidants were found significantly decreased in women with preeclampsia, which allowed us to speculate that there were abnormally increased levels of lipid peroxides. We believe that lipid peroxides are toxic compounds that damage endothelial cells, increase peripheral vasoconstriction and increase thromboxane synthesis and decrease prostacyclin synthesis. We consider that lipid peroxides are not the cause but the effect of oxidative stress induced by ischaemic placenta and leukocytes activation, so the contribute but not induce pathogenesis in preeclampsia.     

A pyrimidine-rich exonic splicing suppressor binds multiple RNA splicing factors and inhibits spliceosome assembly

The bovine papillomavirus type 1 (BPV-1) exonic splicing suppressor (ESS) is juxtaposed immediately downstream of BPV-1 splicing enhancer 1 and negatively modulates selection of a suboptimal 3' splice site at nucleotide 3225. The present study demonstrates that this pyrimidine-rich ESS inhibits utilization of upstream 3' splice sites by blocking early steps in spliceosome assembly. Analysis of the proteins that bind to the ESS showed that the U-rich 5' region binds U2AF65 and polypyrimidine tract binding protein, the C-rich central part binds 35- and 54-55-kDa serine/arginine-rich (SR) proteins, and the AG-rich 3' end binds alternative splicing factor/splicing factor 2. Mutational and functional studies indicated that the most critical region of the ESS maps to the central C-rich core (GGCUCCCCC). This core sequence, along with additional nonspecific downstream nucleotides, is sufficient for partial suppression of spliceosome assembly and splicing of BPV-1 pre-mRNAs. The inhibition of splicing by the ESS can be partially relieved by excess purified HeLa SR proteins, suggesting that the ESS suppresses pre-mRNA splicing by interfering with normal bridging and recruitment activities of SR proteins.     

Helical CT angiography for examination of living renal donors

OBJECTIVE: This prospective study was intended to determine if helical CT arteriography plus conventional radiography is sufficiently accurate to replace and less costly than excretory urography and conventional renal arteriography, the techniques currently used to examine living renal donors. SUBJECTS AND METHODS: Patients underwent CT arteriography with a helical CT scanner. Conventional radiographs were obtained during the pyelographic phase to evaluate the urothelium. Findings on CT arteriograms were compared with findings on conventional arteriograms and at surgery. RESULTS: Of 57 patients who underwent CT arteriography, 46 also underwent conventional arteriography and 40 underwent surgery. For those 46 patients, we found agreement between results of CT arteriography and conventional arteriography in 89% of kidneys. For those 40 patients, we found agreement between results of CT arteriography and findings at surgery in 90% of kidneys and agreement between results of conventional arteriography and findings at surgery in 87% of kidneys. Of the 57 patients, six (11%) had findings on CT angiograms that precluded further consideration for donation. CONCLUSION: Eight to ten percent of renal arteries are not seen on renal arteriograms when compared with findings at surgery. Our results indicate that CT arteriography is as accurate as conventional arteriography at revealing the number of vessels that perfuse and drain the kidneys and can replace conventional arteriography. Use of CT angiography plus conventional radiography instead of excretory urography and conventional arteriography can result in a 35-50% reduction in cost of the imaging studies in potential renal donors.     

Identification of a gene product induced by hard-surface contact of Colletotrichum gloeosporioides conidia as a ubiquitin-conjugating enzyme by yeast complementation

The germinating conidia of many phytopathogenic fungi on hosts must differentiate into an infection structure called the appressorium in order to penetrate their hosts. Chemical signals, such as the host's surface wax or fruit ripening hormone, ethylene, trigger germination and appressorium formation of the avocado pathogen Colletotrichum gloeosporioides only after the conidia are in contact with a hard surface. What role this contact plays is unknown. Here, we describe isolation of genes expressed during the early stage of hard-surface treatment by a differential-display method and report characterization of one of these cloned genes, chip1 (Colletotrichum hard-surface induced protein 1 gene), which encodes a ubiquitin-conjugating enzyme. RNA blots clearly showed that it is induced by hard-surface contact and that ethylene treatment enhanced this induction. The predicted open reading frame (ubc1Cg) would encode a 16.2-kDa ubiquitin-conjugating enzyme, which shows 82% identity to the Saccharomyces cerevisiae UBC4-UBC5 E2 enzyme, comprising a major part of total ubiquitin-conjugating activity in stressed yeast cells. UBC1Cg can complement the proteolysis deficiency of the S. cerevisiae ubc4 ubc5 mutant, indicating that ubiquitin-dependent protein degradation is involved in conidial germination and appressorial differentiation.     

Gross anatomy of the accessory nerve and vagus nerve of the head and cranial neck region in the Bactrian camel

The alpha2-adrenergic system is involved in the regulation of food intake in animals but its effects on feeding in humans are unknown. We hypothesized that clonidine administration would stimulate food intake in healthy human subjects. Ten men and 4 women, all physically and psychiatrically healthy, received clonidine 3 microg/kg or placebo, orally, in blinded, balanced, randomized order. Consumption of a liquid test meal was measured; also, serum growth hormone levels were used as a secondary measure of clonidine effects. Visual analog scale ratings of hunger, satiety, and sedation were obtained before, during, and after the test meal. A subset of five subjects also received 1.5 microg/kg clonidine, in addition to the two trials described above. Test meal consumption was greater following placebo than following clonidine. Sedation ratings were substantially higher at all time points after clonidine and correlated with meal consumption (correlation coefficient r = -0.584; p = 0.028). Hunger and satiety ratings did not differ. The 1.5 microg/kg dose did not provide different effects on feeding from that seen with placebo. Contrary to our hypothesis, clonidine did not stimulate food intake in humans. Sedation associated with clonidine administration may have suppressed any effects on feeding.     

Wigner-Ville analysis of asymptotic signals and applications

The Wigner-Ville joint representation (WVJR) appears as a quite good candidate among the various time and frequency JR. This JR performs exact demodulation of finite energy signals even in presence of linear filtering. Signal or waveform synthesis may be derived from this JR or from ambiguity function. Asymptotic signals are depicted in such a way that modulation parameters may be estimated. Dealing with vibroseismic signals the WVJR allows to identify damping parameters related to propagation effects. Propagation models may be checked by this technique. An example of such a technique is provided by processing of synthetic seismic data.     

Estimations of intra- and extracellular volume and pH by 31P magnetic resonance spectroscopy: effect of therapy on RIF-1 tumours

Quantification of metabolite or drug concentrations in living tissues requires determination of intra- and extracellular volumes. This study demonstrates how this can be achieved non-invasively by 31P magnetic resonance spectroscopy (MRS) employing dimethyl methylphosphonate (DMMP) as a marker of total water space, 3-aminopropylphosphonate (3-APP) as a marker of extracellular space and P and 3-APP as markers of intracellular pH (pH) and extracellular pH (pHe) respectively. The MRS measurements of the tumour volumes were validated by classic radiolabelling methods using 3H2O and [14C]inulin as markers of total and extracellular space respectively. The extracellular volume fraction measured by radiolabelling of RIF-1 tumours was 23 +/- 0.83% (mean +/- s.e.m. n = 9), not significantly different (P > 0.1) from that found by MRS (27 +/- 2.9%, n = 9, London, and 35 +/- 6.7, n = 14, Baltimore). In untreated RIF-1 tumours, pH was about 0.2 units higher than pHe (P < 0.01). 5-Fluorouracil (5FU) treatment (165 mg kg(-1)) caused no significant changes in either pHe or per cent extracellular volume. However significant increases in pH, 48 h after treatment (P < 0.01) correlated with decreased tumour size and improved bioenergetic status [NTP/inorganic phosphate (Pi) ratio]. This study shows the feasibility of an MR method (verified by a 'gold standard') for studying the effects of drug treatment on intra- and extracellular spaces and pH in solid tumours in vivo.