The human sialic acid-binding immunoglobulin-like lectin Siglec-9 and its murine homolog Siglec-E control osteoclast activity and bone resorption

Regulation of osteoclast differentiation and function is a central element in bone homeostasis. While the role of soluble factors, such as cytokines, hormones and growth factors, in controlling osteoclast differentiation has been intensively characterized, the function of surface receptors is less well understood. Sialic acid-binding immunoglobulin-like lectin (Siglec)-9 and its murine homolog Siglec-E are sialic acid-recognizing inhibitory receptors from the CD33-related Siglec-family and mainly expressed on myeloid cells. We found Siglec-9 and Siglec-E to be expressed at all stages of human and murine osteoclastogenesis, respectively. Siglec-E knockout mice displayed lower bone mass despite unchanged osteoclast numbers and an increased bone formation rate. Ex vivo osteoclast assays using Siglec-E knockout cells or a blocking antibody against human Siglec-9 confirmed the suppressive effect of Siglec-9/Siglec-E on osteoclast function. Although osteoclast numbers were unchanged or even slightly decreased, the blockade/absence of Siglec-9/Siglec-E resulted in an augmented resorption activity of mature osteoclasts. This increased resorption activity was associated with enlarged actin rings. Together, our results suggest Siglec-9/Siglec-E to inhibit osteoclast activation independently from osteoclast differentiation and thereby propose a new mechanism for the control of local bone resorption.

Morphological study of bacteria of the respiratory system using fluorescence microscopy of Papanicolaou-stained smears with special regard to the identification of Mycobacteria sp

In Papanicolaou-stained smears certain structures such as nucleoli, Pneumocystis carinii, Charcot-Leyden crystals, bacteria and fungi show a brilliant fluorescence. The morphological characteristics of microorganisms which can be detected by this system, especially mycobacteria, are described. This screening method offers the possibility of providing the clinician with a provisional diagnosis within hours. Proof of the nature of the organisms should be obtained by culture.

[Investigations of changes in the phenolsulphonphthalein plasma levels in pregnant women with EPH syndrome (author's transl)]

In 53 patients, 24 healthy pregnant women and 29 patients with EPH (edema, proteinuria, hypertension) syndrome, the intravenous phenolsulphonphthalein test was performed between the 32nd and 42 weeks of pregnancy. At the same time, the serum creatinine and estrogen excretion in the 24 hour urine were determined. According to this, normal pregnancy and also pregnancies with one or more symptoms of the EPH syndrome without raised blood pressure do not cause changes of the PSP plasma level. A statistically significant rise in the PSP plasma level is only found with a blood pressure of 140/90 mm Hg, and simultaneously a close correlation to the estrogen excretion in the urine (r = -0.4) and the blood pressure (r = 0.6). Estrogen excretion is reduced with increasing blood pressure (r = -0.75). No correlation could be established between the PSP serum level and the creatinine in the serum.