Degradation of collagen by metalloproteinase 2 in patients with abdominal hernias.

BACKGROUND: The groin hernia is a significant social and economic problem of our times. The pathogenesis of the disease is not clear. The metalloproteinases (MMP) are the group of proteolytic enzymes responsible for the degradation of extracellular matrix proteins and the basic membrane of blood vessels. THE AIMS OF OUR STUDY WERE: (1) to estimate the MMP-2 levels in the blood and tissues of patients with a groin hernia; (2) to answer the question of whether changes in MMP-2 activity correlate with the occurrence of inguinal hernias. METHOD: The study was performed on a group of 90 male patients suffering from inguinal hernias, aged 28-70 years (mean: 49 years). The control group was made up of 10 healthy (free from hernia) males, aged 30-68 years (mean: 46 years). RESULTS: We noticed increased levels of MMP-2 in patients with all types of hernia and across all age groups. The MMP-2 mean serum levels were statistically higher in patients with a groin hernia when compared to the control group. The highest blood levels of MMP-2 were observed in young men with a direct hernia. CONCLUSIONS: This study confirmed the important role of MMP-2 in the pathogenesis of inguinal hernia. The increased activity may lead to dysfunctions in collagen fiber, which is responsible for forming fascial structures, and as a result weaken their durability.

Thyroid cryotherapy in an experimental rat model-topography of temperature during therapy and functional results.

The aim of this study was to investigate post cryotherapy thyroid function status of normal rat thyroid tissue and to determine the topography of temperature of cryotreated tissues and of tissues adjacent to them. Nitrous oxide cryotherapy was performed in 40 male Wistar rats. They were divided into four groups of 10. In group I, the right thyroid lobe was subjected to cryotherapy and the left lobe was not frozen. In group II, both thyroid lobes were cryotreated. In group III, the right lobe was frozen and the left lobe was excised. In group IV, the thyroid was subjected to neither cryotherapy nor surgery. During cryotherapy, the temperature in various places of the thyroid and in the surrounding tissues was measured. Serum thyrotropin concentrations were determined before an experiment and 4 weeks after in all rats. The results of temperature measurements proved that it is possible to limit cryotherapy to certain areas of thyroid tissue and to spare the neighboring tissues, because they are not subjected to temperatures that are damaging. The effectiveness of cryotherapy was confirmed by functional effect. Cryotherapy changed function of thyroid tissue. There was a statistically significant difference between mean baseline and follow-up concentrations in rats of groups II and III. In both groups hypothyroidism occurred post cryotherapy.

Thyroid cryotherapy in an experimental rat model.

In recent years cryotherapy has been more and more frequently used for the treatment of tumors of different organs. Until now, the use of cryotherapy for the treatment of thyroid lesions, as well as histopathologic changes in thyroid tissue after cryotherapy, has not been described. Nitrous oxide cryotherapy of one thyroid lobe in twenty 12-week male Wistar rats was performed. After 2 and 4 weeks, the cryotreated thyroid lobe and the second lobe along with a part of the trachea, esophagus, and the subhyoid muscles adhering to the thyroid were excised and assessed macro- and microscopically. The macroscopic evaluation, performed 2 and 4 weeks postcryotherapy, revealed atrophy of the cryotreated lobe in 4 and 3 rats, respectively, and reduction of the cryotreated lobe dimensions in 6 and 7 rats, respectively. In the specimens of the lobes excised 2 weeks following cryotherapy, examined microscopically, necrosis, granulomatous inflammation, hemorrhages, and hemosiderin deposits were found most often, whereas in the specimens of the lobe excised after 4 weeks lymphocytic inflammation and fibrosis were mainly observed. No microscopic changes were observed in the thyroid lobes that were not frozen or in the parathyroid glands located inside these lobes or extrathyroidally, either ipsilaterally or contralaterally to the cryotreated thyroid lobes. There was no microscopic damage to other tissues adjacent to the thyroid gland. No rat developed vocal cord dysfunction after cryotherapy and no significant changes in serum calcium level before and after cryotherapy were observed. The results obtained show that it is possible to cryoblate thyroid tissue without damaging the tissues adjacent to the thyroid, as well as to spare function of the recurrent laryngeal nerves and parathyroid glands.