The effect of compound 48/80 and of electrical field stimulation on mast cells in the isolated mouse stomach

It has been shown that compound 48/80 evokes acid secretion in the isolated mouse stomach by releasing histamine from mast cells. The aim of the present work was to study the distribution and type of mast cells in the isolated mouse stomach and to examine the effect of compound 48/80 and of electrical field stimulation (EFS) on these cells. Histological examination of the stomachs showed only the presence of connective tissue mast cells (CTMC) in all parts of the stomach except in the glandular mucosa where mucosal mast cells (MMC) predominated (MMC -71%, CTMC -29%). Compound 48/80 and EFS did not affect MMC, whereas CTMC showed marked degranulation in all parts of the stomach including the glandular mucosa. It can be concluded that CTMC, present in the gastric mucosa and being sensitive also to EFS, may be involved in the regulation of gastric secretion in the mouse.     

Cryopreservation with glycerol improves the in vitro biomechanical characteristics of human patellar tendon allografts

Purpose

To evaluate the in vitro biomechanical characteristics of patellar tendon ligaments (BTB) when stored as fresh frozen or as glycerol cryopreserved allografts.

Methods

Seventy patellar tendons were harvested from 35 cadaveric human donors and randomly assigned into seven groups. Grafts in group FRESH were mechanically tested within 2 h of harvesting. FROZ-3, FROZ-6, and FROZ-9 were deep-frozen to ?80°C for 3, 6, and 9 months, respectively. Grafts in groups CRYO-3, CRYO-6, and CRYO-9 were initially incubated with 10 % glycerol in a phosphate-buffered saline for 1 h and then stored in glycerol solution (10 % glycerol in PBS) at ?80°C for 3, 6, and 9 months, respectively. Grafts were mechanically tested with two cycling modes (50–250°N and 150–500°N) and then loaded to failure.

Results

Cryopreserved grafts demonstrated more consistent results and expressed lower elongation rates after both cycling loading protocols compared to their frozen counterparts at all storage times. During load-to-failure analysis, ultimate stiffness levels were predominantly higher (23.9–61.5 %) in cryopreserved grafts compared with frozen grafts, and ultimate stress levels were 26 % (13.3–47.7 %) higher, regardless of the storage time. Moreover, cryopreserved grafts revealed similar ultimate elongation and uniformly higher ultimate stiffness and ultimate stress levels compared to fresh grafts.

Conclusion

The results of this in vitro study demonstrated superior mechanical properties of cryopreserved grafts compared to frozen grafts within a preservation period of 9 months. Cryopreservation with glycerol solution might be used to further improve the quality of preserved soft-tissue allografts.     

Using Literature-Based Discovery to Explain Adverse Drug Effects

We report on our research in using literature-based discovery (LBD) to provide pharmacological and/or pharmacogenomic explanations for reported adverse drug effects. The goal of LBD is to generate novel and potentially useful hypotheses by analyzing the scientific literature and optionally some additional resources. Our assumption is that drugs have effects on some genes or proteins and that these genes or proteins are associated with the observed adverse effects. Therefore, by using LBD we try to find genes or proteins that link the drugs with the reported adverse effects. These genes or proteins can be used to provide insight into the processes causing the adverse effects. Initial results show that our method has the potential to assist in explaining reported adverse drug effects.     

Is mast cell histamine involved in the regulation of acid secretion in the guinea pig stomach?

In order to find out whether mast cell histamine is involved in acid secretion in the guinea pig stomach, we tried to answer the following questions. Can the calcium ionophore (CaI), A23187, release enough mast cell histamine to evoke acid secretion? Does electrical stimulation of the vagus nerve (VS) provoke any changes in mast cells in the stomach? In the experiments, an isolated part of guinea pig stomach was used. Preparations from CaI and VS treated groups were examined histologically at the end of experiments. CaI evoked a clear secretory response that was blocked by famotidine. The H2 antagonist also blocked the secretory effect of VS. This result shown that these secretory effects were at least partly mediated by the released histamine. Connective tissue mast cells in CaI treated preparations and in preparations with VS showed significant degranulation. These results support the hypothesis that mast cell histamine could be involved in gastric acid secretion in guinea pig stomach.