[How does vaping products work]. / Comment fonctionnent les produits du vapotage.

To maximize the chances of replacing smoking with vaping, it is necessary to know the different types of existing devices, their characteristics and their most important settings as well as their influence on sensations. To support a user it is also important to understand the nature of the inhaled and exhaled vapor, as well as the possible mistakes that can lead to a less enjoyable experience. Highlighting e-liquids formulations and emissions can help understanding how a minimum of 95 % risk reduction compared to tobacco smoking is achieved and the influence of compounds on the user's experience. At last, a proper care, especially to refill the device and to change the resistance is the key to an effective use over time.

[Ultrasound versus MRI in preventive examinations - a retrospective analysis of 833 patients]. / Stellenwert der Sonografie im Rahmen präventiver Untersuchungen im Vergleich zur Ganzkörper-MRT - eine retrospektive Untersuchung bei 833 Patienten.

PURPOSE: The benefit of ultrasound in comparison with full-body MRI during a medical checkup in preventive health care was examined with regard to the detection of cardiovascular risk factors, metabolic syndrome, malignant tumors and further relevant findings. MATERIALS AND METHODS: 833 consecutive patients (266 f/567 m, age: 19 - 93 y, mean age: 56.6 y) underwent both ultrasound (extracranial carotid arteries, thyroid, abdominal ultrasound and echocardiography) and whole-body MRI (whole-body MR angiography, head, thorax, abdomen and virtual colonoscopy). For ultrasound examinations, DEGUM level III devices were used (Siemens Acuson Antares, Siemens G60, Siemens, Erlangen). MRI examinations were performed using a 1.5 Tesla MRI device (Siemens Avanto, Siemens, Erlangen). All patients were reviewed retrospectively based on the written reports. RESULTS: Ultrasound was much more sensitive in detecting early atherosclerotic changes than MRI angiography. In 33 % of the patients, manifestations of atherosclerosis were found. Thoracic (3) and abdominal aortic and mesenteric artery aneurysms (3) were diagnosed by both methods. Hepatic steatosis as an important risk factor of metabolic syndrome was only found by ultrasound in 20.4 % of our patients. Malignant tumors were rare in this population (1.4 %): all abdominal tumors except one renal oncocytoma were found using both methods. MRI and ultrasound were equally sensitive with respect to the detection of small liver foci. As expected, MRI was less sensitive than ultrasound in the diagnosis of thyroid nodes. For intracranial diagnoses, malignant intrathoracic findings and colonic polyps, ultrasound is not the method of choice. CONCLUSION: For the detection of lifestyle-dependent diseases such as atherosclerosis and metabolic syndrome, ultrasound examination was more sensitive than MRI, and the same was true for the early detection of thyroid diseases. For the detection of malignant abdominal tumors, both methods were equally sensitive. Whole-body MRI can additionally detect pathological changes in the head, lungs and colon.

Very high prevalence of thyroid nodules detected by high frequency (13 MHz) ultrasound examination.

BACKGROUND: The prevalence of thyroid nodules in a healthy population is high: in the German Papillon study, nationwide ultrasound screening of more than 90 000 people using 7.5 MHz scanners revealed the presence of thyroid nodules in 33% of the normal population. A study employing more sensitive 13 MHz scanners has not been conducted so far. MATERIALS AND METHODS: Six hundred and thirty-five consecutive patients (33% female, 67% male, mean 56.7 years) presenting for a preventive health check up underwent ultrasound screening of the thyroid gland (Siemens Acuson Antares, 13 MHz-linear scanner, B-mode and Power mode) and measurement of the basal TSH (thyroid stimulating hormone) value. Size and degree of vascularization of the thyroid gland and of nodules were determined and analysed retrospectively. RESULTS: In 432 of 635 patients, thyroid nodules could be detected with an increasing incidence with age, in 338 without goiter. Mean thyroid size was 12.3 mL for women and 20.5 mL for men correlating strongly with body weight. Fifty-three percentage of the nodules were smaller than 5 mm. Incidence of thyroid dysfunction was only 4%. No cancerous lesions could be found. CONCLUSIONS: Using the 13 MHz technology, we found a substantially higher prevalence of thyroid nodules (68%) than the Papillon study (33%). Even if our population is older than in Papillon, the difference remains in comparable age groups. This is due to the higher sensitivity of 13 MHz scanning. Our study underlines the clinical significance of iodine deficiency and should renew the discussion on routine iodine supplementation.

[Prevention and anti-aging in endocrinology]. / Prävention und "Anti-aging" mit Hormonen Ersetzen, was im Alter fehlt?

The aging process is associated with a characteristic decline in the levels of certain hormones. In both sexes, growth hormones, melatonin, dehydroepiandrosterone (DHEA) and its sulfate compound DHEAS reach their maximum levels in the third decade of life, and then decline progressively. In addition, a constant decrease in the production of biologically active free testosterone of approximately 1% per year is observed in men. The abrupt cessation of sex hormone production seen in women is not observed in men. Irrespective of the hormone being supplemented, it should always be remembered that not merely the hormone-producing organ, but also the target tissue has aged, and may thus manifest a different reaction to the substituted hormone than youthful tissue.

Expression of urocortin in the extravillous human trophoblast at the implantation site.

Urocortin (UCN) is a 40 amino acid peptide which is closely related to corticotropin-releasing hormone and binds with high affinity to both CRH type 1 and type 2 receptors. UCN is expressed in human reproductive tissues including endometrium, ovary, and placenta. This study was designed to investigate the cellular localization of UCN at the implantation site of the human blastocyst, as well as the regulation of the UCN promoter by two major intracellular signaling pathways, the cAMP/PKA and diacylglycerol/PKC pathways, in cells of placental origin. For this reason, immunohistochemistry was performed on tissue sections from paraffin-embedded human first trimester placentas and freshly isolated human invasive extravillous trophoblast cells (EVT) were analyzed for UCN expression using RT-PCR and immunofluorescence. Finally, UCN promoter activity was analyzed in the JEG3 human choriocarcinoma cell line. Immunohistochemistry revealed expression of UCN in the cytotrophoblast, the EVT and decidual cells. Both UCN mRNA and peptide were detectable in freshly isolated EVT. Finally, a human UCN promoter luciferase reporter construct transfected into JEG3 cells was significantly inducible by phorbol ester plus ionomycin, but not by phorbol ester alone or by forskolin. Collectively, the present study reports the expression of UCN in EVT and the activation of the UCN gene promoter by the diacylglycerol/PKC pathway. The functional significance of urocortin for the physiology of EVT requires further investigation.

CEACAM1 impedes thyroid cancer growth but promotes invasiveness: a putative mechanism for early metastases.

CEACAM1, also known as biliary glycoprotein (BGP), CD66a, pp120 and C-CAM1, is a member of the CEA immunoglobulin superfamily. CEACAM1 is a putative tumor suppressor based on diminished expression in some solid neoplasms such as colorectal carcinoma. However, CEACAM1 is overexpressed in some tumors such as non-small cell lung cancer. To clarify the mechanism of action of this cell adhesion molecule, we studied thyroid carcinoma that has a spectrum of morphologies and variable behavior allowing separation of proliferation from invasion and metastasis. CEACAM1 is expressed in thyroid carcinoma cell lines derived from tumors that exhibit aggressive behavior. Introduction of CEACAM1 into endogenously deficient WRO cells resulted in reduced cell cycle progression associated with p21 upregulation and diminished Rb phosphorylation. Forced CEACAM1 expression enhanced cell-matrix adhesion and migration and promoted tumor invasiveness. Conversely, small interfering RNA (siRNA)-mediated downregulation of CEACAM1 expression in MRO cells accelerated cell cycle progression and significantly enhanced tumor size in xenografted mice. CEACAM1 is not appreciably expressed in normal thyroid tissue or benign thyroid tumors. In a human thyroid tissue array, CEACAM1 reactivity was associated with metastatic spread but not with increased tumor size. These findings identify CEACAM1 as a unique mediator that restricts tumor growth whereas increasing metastatic potential. Our data highlight a complex repertoire of actions providing a putative mechanism underlying the spectrum of biologic behaviors associated with thyroid cancer.

Expression of the glucocorticoid receptor in the human adrenal cortex.

Glucocorticoids produced in the adrenal cortex act by binding to a specific intracellular protein, the glucocorticoid receptor (GR), which then modulates gene transcription in target tissues. Whether the adrenal cortex itself is a glucocorticoid target tissue has not been analyzed as yet. Since the presence of GR would be a prerequisite for such "intracortical" glucocorticoid action, this study was designed to analyze GR expression in the normal human adrenal gland using RT-PCR, Western blot, and immunohistochemistry. RT-PCR revealed the presence of GR mRNA in adrenal cortex as well as in NCIh295 cells. These results were confirmed at the protein level by Western blot employing a specific anti-human GR antibody. Immunohistochemically, weak GR staining was observed in the adrenal medulla. In contrast, GR was strongly expressed in the adrenal cortex with the zona reticularis showing the most intense staining. Transfection of a GR-responsive luciferase reporter gene into NCIh295 cells resulted in dexamethasone-dependent induction of luciferase activity, indicating that GR is functional in this tissue. In this study, we show for the first time that GR is expressed in the human adrenal cortex. Its preferential expression in the zona reticularis may indicate a functional role in the regulation of adrenal androgen biosynthesis.

Vitamin B6 modulates glucocorticoid-dependent gene transcription in a promoter- and cell type-specific manner.

Due to their immunosuppressive effects, glucocorticoids (GC) are widely used in the treatment of inflammatory and autoimmune states. However, long-term GC treatment is associated with severe side effects. To increase the ratio of wanted and unwanted GC effects, is, therefore, a desirable goal, which could be achieved by either developing new "dissociating" GC or by combining conventional GC therapy with substances that selectively interfere with glucocorticoid receptor (GR) function. Vitamin B6 was previously shown to inhibit GR transactivation in non-immune cells. In the present study, we tested whether vitamin B6 would also interfere with GR function in immune cells and/or with transrepression in non-immune cells. Normal human lymphocytes and Jurkat T lymphoma cells were transfected with luciferase reporter constructs under the control of the interleukin-2 (IL-2) and the leukemia inhibitory factor (LIF) promoter, respectively. Cells were stimulated with phorbol ester, ionomycin, and different concentrations of dexamethasone, either in the absence (a vitamin B6-free medium was especially prepared for this study) or presence of vitamin B6. Both promoters were strongly induced in response to phorbol ester and ionomycin. Dexamethasone inhibited this effect in a dose-dependent manner both in the presence and absence of vitamin B6. Similar results were obtained at the protein level (IL-2- and LIF-specific ELISAs). Induction of a glucocorticoid response element (GRE)-driven promoter construct by dexamethasone in lymphoid cells was only marginally reduced by vitamin B6. In contrast, GR-mediated transactivation was strongly inhibited by vitamin B6 in HeLa cells, while GR-mediated transrepression of a matrix metalloproteinase 9 (MMP9) promoter construct was not affected. Our data indicate that vitamin B6 does not interfere with GC action in immune cells (wanted GC effects) while selectively inhibiting GR-dependent transactivation in non-immune cells (unwanted GC effects). Combination of GC treatment with supraphysiological doses of vitamin B6 may, thus, reduce the side effects of this type of immunosuppressive therapy, provided that the observed effects can be reproduced at subtoxic vitamin B6 concentrations in vivo.

The glucocorticoid receptor is specifically expressed in the stromal compartment of the human endometrium.

The human endometrium is a classical target tissue for steroid hormones. While the expression pattern and functional roles of both the estrogen receptor (ER) and the progesterone receptor (PR) are well defined, expression of the glucocorticoid receptor (GR) in this tissue has not been described so far. In the present study, we used immunohistochemistry to analyze the expression of GR in the normal human endometrium throughout the menstrual cycle. The expression of GR was compared to that of ER and PR, which were analyzed in parallel. We show that GR is expressed in the human endometrium with a pattern that markedly differs from the expression patterns of ER and PR. ER and PR are expressed in the nuclei of endometrial glands, whereas GR is completely absent from these structures. However, GR is strongly expressed in the stromal compartment of the endometrium throughout the cycle. Both stromal fibroblasts and lymphocytes are GR-positive. In addition GR expression is also observed in the endothelium of small endometrial blood vessels, which are ER- and PR-negative. Western blot analysis performed on endometrial tumor cell lines of glandular (HEC-1B) and mesodermal (SKUT-1B) origin, respectively, showed GR expression only in the latter. In summary, we demonstrate that GR is expressed in fibroblasts, lymphocytes and endothelial cells of the human endometrial stroma, while it is absent from the glandular compartment. The specific expression pattern of GR within the human endometrium points to a possible functional role of glucocorticoids in the process of decidualization which occurs primarily in the stromal compartment.

Identification and tissue distribution of novel KET/p63 splice variants.

The human p53 protein family comprises three members - p53, p63 and p73. Whereas only one p53 variant is known multiple isoforms of p63 and p73 have been described. Depending on the isoform p63 influences p53-responsive genes in a p53-like or -distinct manner. We have cloned multiple splice variants of keratinocyte transcription factor (KET), the rat ortholog of human p63. Several tissue specific variations of exon 1 resulting in different amino-terminal ends were identified. Transactivation properties of the splice variants inversely correlated with the length of the N-termini as determined by activation of the p53-responsive p21 promotor. Multiple KET isoforms are colocalized in different rat tissues. The amino-terminal truncated form DeltaNKETalpha is expressed in epithelial tissues, while expression of the most p53-like KET isotype TAKETgamma was detected in skeletal muscle. Expression of a major KET variant appears to be a cell-type specific rather than a differentiation specific phenomenon.

Expression of leukemia inhibitory factor (LIF) and LIF receptor (LIF-R) in the human adrenal cortex: implications for steroidogenesis.

It is well established that steroidogenesis in the adrenal cortex is regulated by extraadrenal factors, such as ACTH and angiotensin II. However, over the last years, it has become increasingly clear that paracrine and autocrine mechanisms are also important for steroid synthesis in the adrenal gland. The current study was designed to analyze whether the pleiotropic cytokine leukemia inhibitory factor (LIF) and/or its receptor (LIF-R) are expressed in the normal human adrenal cortex, and whether they may play a role in regulating steroidogenesis. Using LIF- and LIF-R-specific primers, we show by RT-PCR that both mRNAs are expressed in this tissue, as well as in the NCI-H295 adrenal carcinoma cell line. The correct sequences of the PCR products were verified by restriction enzyme analysis and DNA sequencing. Immunohistochemistry, employing specific antibodies against LIF and LIF-R, reveals expression of both proteins in the normal human adrenal cortex. Finally, we show that LIF can significantly enhance basal and ACTH-induced production of cortisol and aldosterone in NCI-H295 cells. In summary, we show for the first time that LIF and its receptor are expressed in the normal human adrenal cortex. Our stimulation experiments indicate that the intraadrenal LIF/LIF-R system may participate in regulating adrenal steroidogenesis.

The adhesion molecule CEACAM1 (CD66a, C-CAM, BGP) is specifically expressed by the extravillous intermediate trophoblast.

CEACAM1 (CD66a, C-CAM, BGP) is an adhesion molecule of the carcinoembryonic antigen family which has been shown to be normally expressed at the apical pole of epithelial cells, including the apical pole of endometrial surface and glandular epithelia. The purpose of the present study was to investigate its expression pattern at the maternal-fetal interface, and thus to determine whether CEACAM1 could be implicated in the human implantation process. For this purpose, we performed immunohistochemistry using the 4D1/C2 monoclonal antibody (mAb) as well as flow cytometry and Western blot on isolated trophoblast populations. On the maternal side of the maternal-fetal interface, CEACAM1 was present in epithelial cells of pregnancy endometrium as well as in small endometrial vessels, whereas it was absent from decidual cells. On the fetal side, CEACAM1 was strongly expressed by the extravillous (intermediate) trophoblast at the implantation site, as well as by extravillous trophoblast cells with invasive phenotype in primary culture, as shown by flow cytometry and Western blot. Expression was also observed in placental villous core vessels but was absent from both villous cyto- and syncytiotrophoblasts throughout the pregnancy. We conclude that, given its specific expression pattern, CEACAM1 can be a useful marker for extravillous intermediate trophoblast and might be functionally implicated in mediating trophoblast/endometrial and/or trophoblast/endothelial interactions during the trophoblastic invasion of the endometrium.

Molecular mechanisms of dissociative glucocorticoid activity.

BACKGROUND: Glucocorticoids mediate their effects on target cells via transactivation and transrepression of certain target genes. While conventional glucocorticoids do not distinguish between transactivation and transrepression, new glucocoticoids should be able to dissociate these effects, thus lowering the potential of unwanted side-effects of glucocorticoids in clinical use. In this study, we developed a new experimental system to test potentially selective glucocorticoids in normal lymphocytes. MATERIALS AND METHODS: Following pretreatment with phytohaemagglutinin, normal lymphocytes were transfected, using electroporation, with pGL3 luciferase reporter vectors under the control: (1) of the human IL-2 promoter; and (2) of a glucocorticoid response element (GRE). Luciferase activity was measured in response to various steroid compounds, including the potentially dissociative glucocorticoid medroxyprogesterone acetate (MPA). RESULTS: The IL-2 promoter was induced 267.2 +/- 27.5-fold (mean +/- SD) by phorbol ester and ionomycin. In these cells, hydrocortisone and dexamethasone caused a 22.9 +/- 3.6% and a 38.4 +/- 10% reduction in luciferase activity, respectively. Under GRE control, hydrocortisone stimulated luciferase activity 6.4 +/- 0.50-fold and dexamethasone 8.2 +/- 0.4-fold. MPA-induced transrepression was 73.3 +/- 7.2% for the IL-2 promoter, and transactivation was 2.4 +/- 0.4-fold with the GRE-driven construct. The natural progestin progesterone did not have significant effects on either construct. CONCLUSIONS: This is the first system that allows efficient analysis of glucocorticoid-dependent transactivation and transrepression in normal human lymphocytes. Compared to conventional glucocorticoids, MPA can be referred to as a dissociative glucocorticoid, its transrepression/transactivation ratio being 6.6 (transrepression 1.91/transactivation 0.29), with dexamethasone being the standard (transrepression 1/transactivation 1). We conclude that MPA is a highly promising substance for the treatment of autoimmune/inflammatory diseases.

The peripheral CRH/urocortin system.

The hypothalmus-pituitary-adrenal (HPA) axis and the immune system communicate at multiple levels: On the one hand, immune system-derived substances, such as interleukin-1, interleukin-6, tumor necrosis factor alpha, and leukemia inhibitory factor can stimulate the HPA axis. On the other hand, HPA axis-derived substances, most importantly glucocorticoids, can modulate the immune response. Furthermore, factors that were originally thought to be restricted to the HPA axis have been found to be expressed by immune cells. Proteins belonging to the CRH (corticotropin-releasing hormone) family represent important examples of such hormones. In the early 1990s, it was shown that immunoreactive CRH was present at sites of chemically induced inflammation. Administration of anti-CRH antibodies reduced the degree of inflammation, pointing to a pro-inflammatory role of "peripheral" CRH. We and others could show that lymphocytes are one source of immunoreactive CRH; however, the antiserum used in our study as well as in previous reports crossreacted with urocortin, a newly discovered member of the CRH family. Using RT-PCR, we could clearly demonstrate that human lymphocytes expressed urocortin but not CRH mRNA. These results were confirmed by immunocytochemistry, employing urocortin- and CRH-specific antibodies, respectively. The possible functional roles of urocortin expression in the immune system are discussed.

Dissociative glucocorticoid activity of medroxyprogesterone acetate in normal human lymphocytes.

The immunosuppressive effects of glucocorticoids (GC) have led to their wide application in the treatment of inflammatory and autoimmune states. However, long term GC treatment is associated with severe side-effects. The development of agents displaying a more favorable ratio of wanted and unwanted GC effects, is, therefore, a major goal of pharmacological and clinical research. In this study, the progesterone receptor agonist medroxyprogesterone acetate (MPA), which also binds to the glucocorticoid receptor (GR), was tested with regard to its immunosuppressive properties. Using a recently established electroporation protocol, we show that MPA (but not progesterone) can suppress a human interleukin-2 (IL-2) promoter-luciferase construct to the same extent as the synthetic GC dexamethasone in normal human lymphocytes. MPA also markedly suppressed IL-2 (as well as IL-1 and IL-6) release, as assessed by specific enzyme-linked immunosorbent assays. In contrast, a highly dexamethasone-inducible glucocorticoid response element-driven promoter construct was only marginally stimulated by MPA in both normal human lymphocytes and HeLa cells. RT-PCR and Western blot analysis of normal human lymphocytes revealed that they do not express progesterone receptor messenger ribonucleic acid and protein, respectively. In contrast, the GR protein was clearly detectable in all samples and was shown to mediate the effects of MPA in transfected Jurkat T lymphoma cells. Our data indicate that 1) MPA can transrepress the human IL-2 gene in normal human lymphocytes in the absence of significant trans-activation; and 2) this effect is mediated by GR. Because of its dissociative GC activity, MPA is a highly promising substance for the treatment of inflammatory/autoimmune states.

Telomerase activity in benign and malignant adrenal tumors.

Histological analysis of surgically removed adrenal masses often fails to differentiate between benign and malignant tumors. In normal cells, the telomeric ends of the chromosomes are shortened with each cell division, leading to chromosome destabilization and cellular senescence after a critical number of cell cycles. In tumor cells, telomere shortening is prevented by a specific DNA polymerase, called telomerase. In an effort to clarify the role of telomerase in the pathogenesis of adrenal tumors, and to test whether its activity could serve as marker of malignancy, we measured telomerase activity in 41 human adrenal tissue samples that were classified both by the clinical course and by histological examination. Telomerase activity was determined by TRAP ELISA and expressed as high (>50% of positive control telomerase activity), medium (31-50%), low (11-30%), very low (< or = 10%), or absent (0%). The 8 normal adrenal tissue samples showed very low levels of telomerase activity. Mean telomerase activity also very low in 3/3 incidentalomas, 6/6 Cushing adenomas, 6/6 Conn adenomas, 7/7 adrenocortical carcinomas, 8/8 benign pheochromocytomas, and 2/3 malignant pheochromocytomas. In contrast, one malignant pheochromocytoma showed high telomerase activity. These data indicate that telomerase activity may not be a suitable marker for malignancy in the adrenal gland. Our results also challenge the current dogma of close correlation between cell dedifferentiation and telomerase activity.

Expression patterns of the cell-cycle inhibitor p27 and the cell-cycle promoter cyclin E in the human placenta throughout gestation: implications for the control of proliferation.

The rapid development of the placenta necessitates a high proliferative potential and cell-division rate. This, coupled with a high capacity for invasion, could confer on the placental tissue a tumour-like character. To exclude this, tight mechanisms of control are necessary for both proliferation and invasiveness. Despite their importance, very little is known about the molecular basis of these mechanisms. The present study was thus designed to investigate the molecular mechanisms implicated in the control of proliferation in the human placenta. We used immunohistochemistry to study the expression of two cell-cycle controlling molecules with opposing effects: the cell-cycle inhibitor, p27, which belongs to the Kip/Cip family of CDK inhibitors and can mediate G1 arrest, and cyclin E, a G1-cyclin esential for G1/S progression. Expression was studied throughout pregnancy in a total of 41 normal human placental samples. In addition, immunohistochemistry for Ki-67 was performed as a control for proliferation. The cell-cycle inhibitor p27 was expressed in the differentiated, non-dividing syncytiotrophoblast, while expression of cell-cycle promoter cyclin E was localized to the nuclei of the cytotrophoblast and correlated well with expression of Ki-67. No cyclin E expression was observed in the syncytiotrophoblast. In conclusion, strong expression of the cell-cycle inhibitor p27 and absence of expression of cyclin E in the syncytiotrophoblast might represent an important control mechanism in placental proliferation. This differentiates it from the proliferation of malignant tumours, where p27 has been shown to be frequently downregulated while cell cycle promoters are overexpressed.