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H Wayland

Publications and source records attributed to H Wayland.

12 recordsLinked to original sources

Intravital observatories. Dream or necessity.

Among the major challenges confronting biomedical studies today two stands out above all others: 1. The need for a better interrelation of the remarkable findings of molecular and cell biology to living systems through careful intravital observation; and 2. The need for a more rapid and skillful application of the findings and methods of intravital observation to clinical applications. Major progress on either or both of these problems will require much greater emphasis on multidisciplinary studies of living animals involving a considerably wider variety of disciplines than has been brought to bear on them to date, plus the availability of the finest and most advanced technology. The cost in both money and manpower to achieve major breakthroughs is such that these goals can only be accomplished by having a few centers of excellence in which both a diversity of skills and of equipment can be made available to as wide a spectrum of the biomedical community as possible. It is the contention of this author that this can best be achieved by establishing a few methods-oriented centers of excellence for Intravital Observation which he has called Intravital Observatories. It is urged that the community of microcirculationists, which has long been a leader in a multidisciplinary approach to physiological studies and has made many of the outstanding advances in intravital microscopy, take the lead in making this major contribution to biomedicine.

Academies and Institutes

Microcirculatory stasis precedes tissue necrosis in ethanol-induced gastric mucosal injury in the rat.

The relation of blood flow stasis to the development of unequivocal histologic necrosis (loss of parietal cells from the column of contiguous cells) in ethanol-induced gastric mucosal injury was studied in anesthetized rats. The most rapid vascular change that occurred when the gastric mucosa was exposed to 100% ethanol was a severe segmental constriction of the large submucosal venules. At 22 sec, the average venular diameter was 52.2 +/- 6.0% of the original one. This was followed by complete superficial mucosal blood flow stasis at 49 +/- 4 sec and appearance of histologic evidence of necrosis in one of seven rats at 2.5 min, four of six rats at 10 min, and seven of seven rats at 60 min. We conclude that in ethanol-induced gastric mucosal injury, submucosal venular constriction occurs first, followed by cessation of mucosal blood flow to be followed later on with histologic evidence of necrosis.

Animals

Role of arachidonic acid metabolites in ethanol vasoaction in rat gastric submucosa.

By use of an in vivo microscopy technique in the anesthetized rat, the effect of 0.5-8.0% ethanol on gastric submucosal blood vessel diameter was studied. The direct application of ethanol onto the exposed submucosal vasculature caused a dose-dependent dilatation of the arterioles (9 +/- 3% by 2% ethanol) but had no effect on venular diameter. In rats pretreated with 5 mg/kg indomethacin subcutaneously to inhibit cyclooxygenase activity, the submucosal application of ethanol caused dose-dependent constriction of both arterioles and venules (2% ethanol decreasing diameters by 21 +/- 3 and 15 +/- 2%, respectively). This constriction by ethanol in indomethacin-pretreated rats was significantly inhibited by BW755C, a lipoxygenase inhibitor. Under these conditions, 2% ethanol had no significant effect on either arterioles or venules. In conclusion, ethanol appears to cause release of vasodilating prostaglandins and vasoconstricting leukotrienes that may mediate or modulate the microvascular response to ethanol.

4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyraz