[Stroke and hypertension]

Arterial hypertension is the most important risk factor for stroke. Many interventional trials have unambiguously proven the benefit of antihypertensive therapy in both primary and secondary prevention for all age categories. No recommendation for any single antihypertensive substance for the primary prevention of stroke exists. Achieving the therapeutic goal (normotension) is the crucial factor. In most patients, multiple combinations of antihypertensive drugs are required to do this. For high-risk patients and in secondary prevention, substances inhibiting the renin-angiotensin-system, especially combined with calcium antagonists and indapamid, may be advantageous, while beta-blockers appear to be less well suited. In patients suffering from left-ventricular hypertrophy or atrial fibrillation, sartanes are the best-documented drug class. As TIA or stroke will often disturb the normal circadian rhythm of blood pressure and eliminate the usual night-time drop, monitoring of the therapeutic results must include ambulatory 24h measurements. The interrelation between vascular dementia and hypertension is by now also considered proven. An early start of antihypertensive treatment can prevent the development of dementia and impaired cognitive function.

The combination of amlodipine/valsartan 5/160 mg produces less peripheral oedema than amlodipine 10 mg in hypertensive patients not adequately controlled with amlodipine 5 mg

AIMS

To demonstrate the benefit of the combination amlodipine/valsartan 5/160 mg over amlodipine 10 mg, in producing a lower incidence of peripheral oedema for a comparable mean sitting systolic blood pressure (MSSBP) reduction.

METHODS

After a 4-week amlodipine 5 mg run-in phase, inadequately controlled hypertension patients (aged > or = 55 years, MSSBP > or = 130 and < or = 160 mmHg) were randomised to receive amlodipine/valsartan 5/160 mg or amlodipine 10 mg for 8 weeks, followed by amlodipine/valsartan 5/160 mg for 4 weeks for all patients. Primary variables were MSSBP change from baseline to week 8 and incidence of peripheral oedema reported as an AE. Resolution of peripheral oedema was assessed 4 weeks after switching patients from amlodipine 10 mg to amlodipine/ valsartan 5/160 mg.

RESULTS

At week 8, MSSBP showed greater reduction with amlodipine/valsartan 5/160 mg than amlodipine 10 mg (least square mean: -8.01 vs.-5.95 mmHg, p < 0.001 for non-inferiority and p = 0.002 for superiority). Systolic control, overall BP control and systolic response rate at week 8 were significantly higher with combination than amlodipine 10 mg (34 vs. 26%; 57 vs. 50%; 36.57 vs. 27.77%, respectively). Incidence of peripheral oedema was significantly lower with the combination than amlodipine 10 mg (6.6 vs. 31.1%, p < 0.001). Peripheral oedema resolved in 56% patients who switched from amlodipine 10 mg to the combination, without the loss of effect on BP reduction.

CONCLUSION

In non-responders to amlodipine 5 mg, treatment with amlodipine/valsartan 5/160 mg induced significantly less peripheral oedema than amlodipine 10 mg for similar BP reduction. Peripheral oedema resolved in > 50% patients switching from amlodipine 10 mg to the combination.

[Selective cervical lymph node dissection for primary, node-negative, oral squamous cell carcinoma: oncologic assessment and clinical relevance of prognostic factors for secondary local metastasis]

BACKGROUND

The aim of this retrospective study was to evaluate prognostic factors for the development of secondary local lymph node metastases in patients with oral squamous cell carcinoma who had undergone selective neck dissection for primary node-negative disease.

PATIENTS AND METHODS

The study included 331 patients with primary squamous cell carcinoma of the oral cavity who underwent 431 selective neck dissections between January 1986 and December 2002 in Germany at the Hannover Medical School's Department of Oral and Maxillofacial Surgery. Several potential prognostic factors were evaluated for their influence on the development of secondary metastases following primary neck dissection.

RESULTS

No statistically significant relationship to the appearance of secondary local metastasis following selective neck dissection was detected concerning: patient age or sex, histopathologic tumor stage, primary tumor grade, or adjuvant therapies such as pre- or postoperative radiotherapy and radiochemotherapy. The only study factor with a statistically significant influence was the extent of lymphadenectomy, in which particularly the region of the carotid bifurcation played a decisive role.

CONCLUSION

Significantly fewer secondary metastases occurred following neck dissections that included the carotid trigone. In light of these results, we recommend that neck dissection for primary oral squamous cell cancer always include the region of the carotid bifurcation, regardless of the above mentioned associated patient and tumor factors.

Biglycan Is Required for Adaptive Remodeling After Myocardial Infarction

Background— After myocardial infarction (MI), extensive remodeling of extracellular matrix contributes to scar formation and preservation of hemodynamic function. On the other hand, adverse and excessive extracellular matrix remodeling leads to fibrosis and impaired function. The present study investigates the role of the small leucine-rich proteoglycan biglycan during cardiac extracellular matrix remodeling and cardiac hemodynamics after MI.

Methods and Results— Experimental MI was induced in wild-type (WT) and bgn −/0 mice by permanent ligation of the left anterior descending coronary artery. Biglycan expression was strongly increased at 3, 7, and 14 days after MI in WT mice. bgn −/0 mice showed increased mortality rates after MI as a result of frequent left ventricular (LV) ruptures. Furthermore, tensile strength of the LV derived from bgn −/0 mice 21 days after MI was reduced as measured ex vivo. Collagen matrix organization was severely impaired in bgn −/0 mice, as shown by birefringence analysis of Sirius red staining and electron microscopy of collagen fibrils. At 21 days after MI, LV hemodynamic parameters were assessed by pressure-volume measurements in vivo to obtain LV end-diastolic pressure, end-diastolic volume, and end-systolic volume. bgn −/0 mice were characterized by aggravated LV dilation evidenced by increased LV end-diastolic volume ( bgn −/0 , 111±4.2 μL versus WT, 96±4.4 μL; P <0.05) and LV end-diastolic pressure ( bgn −/0 , 24±2.7 versus WT, 18±1.8 mm Hg; P <0.05) and severely impaired LV function (EF, bgn −/0 , 12±2% versus WT, 21±4%; P <0.05) 21 days after MI.

Conclusion— Biglycan is required for stable collagen matrix formation of infarct scars and for preservation of cardiac hemodynamic function.

Expression and activation of mTOR in neuroendocrine tumors. Effects of mTOR inhibition by RAD001 upon growth, cell cycle regulation and signalling in neuroendocrine cell lines

10570

Background: Molecular pathogenesis of neuroendocrine tumors of the digestive tract is largely unknown. We examined paraffin sections of different types of neuroendocrine tumors for expression of activated kinases involved in regulation of growth and protection against apoptosis. In addition, we studied effects of a newly developed inhibitor of mTOR (RAD001) upon growth, cell cycle regulation and signaling in two different neuroendocrine cell lines. Methods: Immunohistochemistry with antibodies for native and activated signaling kinases was performed on paraffin sections. MTT assays were used to determine growth rates of neuroendocrine cell lines and FACS analysis was performed for cell cycle analysis. Immunoblotting revealed activation of kinases. Results: Extracellular activated kinase 1/2 (ERK1/2), cAMP regulated element binding protein (CREB), protein kinase B (PKB) and mTOR were expressed in the majority of insulinomas (n = 40) and serotonin-producing neuroendocrine tumors (carcinoids, n = 49). Phosphorylated forms of these kinases corresponding to their activated state were also detected in these tumors. Most neuroendocrine tumors expressed high levels of activated CREB, PKB and mTOR whereas phosphorylated ERK1/2 was present only a minority of dNETs. Inhibition of mTOR kinase by different concentrations of RAD001 induced growth arrest in insulinoma (INS-1) and human neuroendocrine serotonin-producing cells (BON) in concentrations between 10 and 100 nM. Interestingly, we observed pronounced synergism between octrotide and RAD001 upon growth inhibition in these cell lines. Growth inhibition by RAD001 corresponded to decreased S-phase and increased G0/G1 peak in cell cycle analysis. RAD001 inhibited effectively phosphorylation of mTOR with an IC50 of 10 nM. However, we observed only minor inhibition of PKB and CREB by RAD001 and partial inhibition of ERK signaling by RAD in concentrations between 100 nM and 1 μM. Conclusions: mTOR is expressed and activated in different neuroendocrine tumors and inhibition of mTOR by RAD001 induces growth inhibition, cell cycle arrest and decreased signaling by mTOR and ERK1/2 in neuroendcrine cell lines INS-1 and BON.

No significant financial relationships to disclose.

Cytokine-induced osteoprotegerin expression protects pancreatic beta cells through p38 mitogen-activated protein kinase signalling against cell death

AIMS/HYPOTHESIS

Pro-inflammatory cytokines play a crucial role in immune-mediated beta cell destruction, an essential mechanism in the pathogenesis of type 1 diabetes mellitus. Microarray analysis recently identified osteoprotegerin (OPG; now known as tumour necrosis factor receptor superfamily, member 11b [TNFRSF11B]) as a cytokine-induced gene in beta cells. The aim of the present study was to characterise the functional role and signalling pathways of OPG that are involved in cytokine-induced beta cell death.

MATERIALS AND METHODS

As cellular models, the rat beta cell line INS-1E and human primary pancreatic islets were employed. The effects of IL-1beta and TNF-alpha on OPG expression were characterised by northern blot and immunoassay. The effect of OPG on beta cell survival was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Signalling pathways were evaluated by western blot analysis using antibodies against p38 mitogen-activated protein kinases (MAPK), c-Jun N-terminal kinase and extracellular signal-regulated kinase 1/2.

RESULTS

The INS-1E cell line and primary pancreatic islets expressed OPG mRNA and secreted OPG protein, both of which were enhanced by IL-1beta and TNF-alpha. Exposure to IL-1beta resulted in sustained phosphorylation of p38 MAPK in INS-1E cells and subsequent cell death. Administration of exogenous OPG prevented both IL-1beta-induced beta cell death and sustained p38 MAPK phosphorylation.

CONCLUSIONS/INTERPRETATION

Our data indicate that cytokine-induced production of OPG may protect beta cells from further damage. This protective effect is, at least in part, mediated through inhibition of p38 MAPK phosphorylation. Thus OPG is an autocrine or paracrine survival factor for beta cells.

Stressassoziierte Hypertonie am Arbeitsplatz - Ergebnisse des STARLET-Projekts

BACKGROUND AND OBJECTIVE

To assess the influence of work stress and initial blood pressure on the prognosis of hypertension.

SUBJECTS AND METHODS

In a prospective, controlled, multicentre, observational study, ambulatory 24-hour blood pressure measurements (ABPM) of employees from different work places were recorded at the work place on working days. Recurrent ABPM were performed for up to 5 years on 3448 subjects (mean age 44.6 years) who gave consent for follow-up. Subjects with hypertension were told to consult their family doctor so that they could receive antihypertensive treatment (the angiotensin receptor blocker eprosartan, an ACE-inhibitor or a beta-blocker were recommended for initial treatment). Subjects were classified as being in mental strain (stress-positive [stress+]/ stress-negative [stress-]), using standardized questionnaires.

RESULTS

Only 1242 (36.0%) of the 3448 employees (69.% males) were normotensives. Only 166 (7.5%) of the 2206 hypertensives had normal ABPMs (<135/85 mmHg) and received antihypertensive treatment at the time of inclusion into the trial. During follow-up 57.8% of patients were treated with eprosartan or ACE-inhibitors, 34.6% with beta-blockers. By the time of the final visit 80.5% of hypertensives had achieved improvement of systolic and/or diastolic blood pressures (29.1% normotensive). Patients with hypertensive ABPM at baseline had more cardiovascular events than normotensives (normotensives 3.0%; grade 1 7.8%, grade 2-3 9.8%). Hypertensive ABPMs at the last follow up or an increase in blood pressure grade were associated with higher event rates than normotensives (stable normotensives 1.8% events vs. stable hypertensives 7.9%, vs. worsening or grade 2-3: 9.1%) More hypertensives were classified as stress+ than normotensives. Persons classified as stress- (or changing to stress-) had fewer events (6.2%) than those regarded as stress+ or changing to stress+ (7.1%). Persons regarded as stable stress- had lower mean blood pressures than those who were stable stress+. Change to another stress group was associated with an increase or decrease of mean blood pressure.

CONCLUSIONS

Many employed people are hypertensive at work and are not treated adequately. ABPM control and antihypertensive treatment based on eprosartan, ACE-inhibitors or beta-blockers resulted in a significant increase in the number of patients with lower blood-pressure levels and a reduction in cardiovascular events. Patients under mental strain were more likely to be hypertensive. Mental strain was associated with changes in blood pressure.

The genome of black cottonwood, Populus trichocarpa (Torr. & Gray)

We report the draft genome of the black cottonwood tree, Populus trichocarpa. Integration of shotgun sequence assembly with genetic mapping enabled chromosome-scale reconstruction of the genome. More than 45,000 putative protein-coding genes were identified. Analysis of the assembled genome revealed a whole-genome duplication event; about 8000 pairs of duplicated genes from that event survived in the Populus genome. A second, older duplication event is indistinguishably coincident with the divergence of the Populus and Arabidopsis lineages. Nucleotide substitution, tandem gene duplication, and gross chromosomal rearrangement appear to proceed substantially more slowly in Populus than in Arabidopsis. Populus has more protein-coding genes than Arabidopsis, ranging on average from 1.4 to 1.6 putative Populus homologs for each Arabidopsis gene. However, the relative frequency of protein domains in the two genomes is similar. Overrepresented exceptions in Populus include genes associated with lignocellulosic wall biosynthesis, meristem development, disease resistance, and metabolite transport.

An aqueous–organic two-phase bioprocess for efficient production of the natural aroma chemicals 2-phenylethanol and 2-phenylethylacetate with yeast

The natural aroma chemicals 2-phenylethanol (2-PE) and 2-phenylethylacetate (2-PEAc) are of high industrial relevance and can be produced from L-phenylalanine in a yeast-based process with growth-associated product formation. Due to product inhibition, in situ product removal is mandatory to obtain economically interesting concentrations. A fed-batch approach using polypropylene glycol 1200 as in situ extractant and the precursor in a saturated concentration led to the highest 2-PE productivity reported for a bioprocess so far. With Kluyveromyces marxianus CBS 600, 26.5 g/l 2-PE and 6.1 g/l 2-PEAc in the organic phase were obtained, corresponding to space-time yields of 0.33 and 0.08 g/l h, respectively.