Brief report: first identification of H4 histamine receptor in healthy salivary glands and in focal sialadenitis in Sjögren's syndrome.

OBJECTIVE: The conventional H(1) and H(2) histamine receptors have >10,000-fold lower avidity for histamine than H(4) histamine receptor, which has been implicated in autoimmune diseases. This study was undertaken to compare H(4) histamine receptor levels in the salivary glands (SGs) of healthy controls with those in the SGs of patients with primary Sjögren's syndrome (SS). METHODS: H(4) histamine receptor messenger RNA (mRNA) was analyzed using real-time quantitative polymerase chain reaction, and the receptor protein was examined using immunostaining. Effects of the H(4) histamine receptor agonist ST-1006 on cytokine synthesis by human SG (HSG) cells were analyzed using xMAP technology and enzyme-linked immunosorbent assay. RESULTS: Healthy SGs contained H(4) histamine receptor mRNA. The receptor protein was localized to the acinar and ductal epithelial cells. H(4) histamine receptor agonist stimulated HSG cells to produce the cytokines interleukin-8 and vascular endothelial growth factor. SS patients had low H(4) histamine receptor levels. CONCLUSION: H(1) and H(2) histamine receptor antagonists are not effective in the treatment of autoimmune diseases. However, such antagonists do not affect the newly discovered H(4) histamine receptor. Dendritic cells and lymphocytes are nonprofessional histamine-producing cells, which produce histamine at 100-1,000-fold lower rates than mast cells do. Saliva contains only 0.31-12.4 ng/ml histamine, which is too low to stimulate H(1) or H(2) histamine receptor, but stimulates H(4) histamine receptor half maximally. Our findings show that H(4) histamine receptor is strongly expressed in tubuloacinar SG cells, which emphasizes the role of these cells in the pathogenesis of SS.

Salivary glands - "an unisex organ'?

Usually no distinction is made between female and male salivary glands although cyclic changes of and / or differences in serum and salivary sex steroid concentrations characterize women and men. Moreover, sexual dimorphism is well recognized in salivary glands of rodents.Salivary glands contain estrogen and androgen receptors and are, according to modern high throughput technologies,subjected to gender differences not explainable by gene dose effects by the X chromosome alone. Because sex steroids are lipophilic, it is often thought that approximately 10% of them passively diffuse from plasma to saliva. Indeed, saliva can find use as sample material in sports medicine, pediatrics, veterinary medicine and behavioral sciences. Last but not least, humans and other primates are unique in that they have a reticular zone in their adrenal cortex, which produces dehydroepiandrosterone and androstendione pro-hormones. These are processed in peripheral tissues, not only in female breast and uterus and male prostate, but also in salivary glands by an intracrine enzymatic machinery to active 17b-estradiol,dihydrotestosterone and others, to satisfy and buffer against a constantly changing needs caused by circadian,menstrual, pregnancy and chronobiological hormonal changes in the systemic circulation. Female dominance of Sjögren's syndrome and certain forms of salivary gland cancer probably reflect these gender-based differences.

[The choice of the radiation parameters in the laser reconstruction of the pupil]. / K vyboru parametrov izlucheniia pri lazernoi rekonstruktsii zrachkovogo otverstiia.

The phenomenon of a "local punch" of tissues in the zone of nano- or picosecond impulses of neodymium: YAG-laser radiation focusing allows to increase energy in the pulse by one order as compared with traditionally used energy. At this, in order to achieve the initial effect it becomes possible to reduce the number of shots by two orders and thus to increase the spot of radiation. The summary energy of action absorbed in the eye remains the same and that's why the number of complications doesn't increase. The widening of possibilities to choose a laser source for micro- and macroperforations allows, when prescribing the treatment, to more reliably consider clinical peculiarities in each concrete case.