Hybridization dependent cleavage of internally modified disulfide-peptide nucleic acids

Selectivity of the cleavage of single stranded over hybridized forms of internally modified disulfide-peptide nucleic acids (PNA) has been optimized using a series of phosphines and thiols, which have different sizes and charges. For the most selective cleaver found (tris-(carboxyethyl)-phosphine), reactivity of single stranded PNA is 33 times higher than that of the PNA-DNA duplex. Selectivity of single stranded disulfide-PNA cleavage has been explained in terms of electrostatic interaction between the substrate and the cleaver.     

IKCa-channel blockers. Part 2: discovery of cyclohexadienes

Novel cyclohexadienes have been identified as potent and specific IK(Ca)-channel blockers. In this communication we describe their synthesis as well as their chemical and biological properties. A selected derivative is being enriched in rat brain and reduces the infarct volume, intracranial pressure as well as the water content in a rat subdural hematoma model of traumatic brain injury after iv administration.     

Analysis of morphology of adrenal pheochromocytoma as regards their potential malignancy

BACKGROUND: Adrenal pheochromocytoma are diagnosed the most often in patients with arterial hypertension or with thyroid medullar cancer and suspicion of MEN II syndromes. The aim of the study is to analyse the morphology of pheochromocytomas on the basis of Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) in order to estimate their potential malignancy. MATERIAL AND METHODS: Forty tumours were subjected to analysis. Mean patients age was 45.2+/-13.4 years. The diagnosis of pheochromocytoma was establish before surgery in 87.5%. 12.5% of patients were referred to surgery on the basis of tumour diameter (range 70 to 102 mm). In 20.0% of patients MEN II syndromes were diagnosed. RESULTS: In pathological examination benign pheochromo-cytoma was diagnosed in 39 presented patients. In 1 cases malignant form of pheochromocytoma was diagnosed on the basis of lymph nodes metastases. Number of points in PASS was >or=4 in 9 of 40 tumours (22.5%). Among 35 patients operated on more than 12 months ago 2 patients died: 1 patient with malignant pheochromocytoma (PASS=8 points) and 1 patient with MEN IIA syndrome (due to disseminated thyroid medullar cancer). In remaining 7 observed patients with PASS>or=4 points neither recurrence nor metastases were diagnosed within the period of observation (13-90 months). In 1 out of patients with PASS<4 points a local recurrence was surgically removed 82 months after primary operation. CONCLUSION: Analysis of pheochromocytoma in PASS is only of rough character and does not allow for clear-cut histological diagnosis of benign and malignant tumours. The only unquestionable criterion of pheochromocytoma's malignancy remain metastases.     

Radioisotope therapy with somatostatin analogues in neuroendocrine tumours (case report)

Restricted number of neuroendocrine tumors (NET) shows overexpression of somatostatin receptors. Therefore, long-acting somatostatin analogues are used in diagnosis and treatment of those tumors. Here we present our first case of NET, localized in pancreas treated with DOTA-D-Phe 1-Tyr 3-octreotide (DOTATATE), for receptor-mediated radioisotope therapy. DOTATATE is a newly developed somatostatin analogue labeled with beta-emitter yttrium 90 (90Y) and beta, gamma-emitter lutetium 177 (177Lu). A 34-year old woman was suffering from several years gastrointestinal symptoms. NET of the pancreas with multiple metastases into the liver was diagnosed based on histopatological, biochemical and radiological tests. First, she had chemiotherapy (leucovorin, 5-FU, cisplatin), however there was any positive effects of this therapy. Next, she received four single doses of 90Y DOTATATE at 4-6- week intervals, yielding a cumulative dose of 7.4 GBq/m2. During the 4th cycle the Lu-177 DOTATATE was additionally administered. As a renal protection i.v. infusion of amino acid solution were used during the treatment sessions. To date, patient has shown partial remission with reduction of tumor masses. We observed spectacular clinical, biochemical and radiological improvement. Radioisotope therapy could be a powerful and promising method of treatment at least in patients who had no other treatment option.     

Structure and function of the betaine uptake system BetP of Corynebacterium glutamicum: strategies to sense osmotic and chill stress

The soil bacterium Corynebacterium glutamicum has to cope with frequent fluctuations of the external osmolarity and temperature. The consequences of hyperosmotic and chill stress seem to differ, either causing dehydration of the cytoplasm or leading to impairment of cellular functions due to low temperature. Nevertheless, a particular type of regulatory response, namely the accumulation of so-called compatible solutes, is induced under both conditions. Compatible solutes are known to stabilize the native conformation of enzymes, which may be affected by osmotic and chill stress. BetP is a high-affinity uptake carrier for the compatible solute glycine betaine in C. glutamicum. BetP includes, besides its catalytic function, the ability to sense hyperosmotic conditions and chill stress. As a consequence, the carrier is activated in dependence of the extent of these types of stress. The signal input related to these changes of the environmental conditions is based on at least two different mechanisms. In case of hyperosmotic stress, BetP responds to the internal potassium concentration as a measure for hypertonicity, whereas chill stress is detected by an independent signal, most probably changes of the physical state of the membrane.     

Production of IL-12 by human monocyte-derived dendritic cells is optimal when the stimulus is given at the onset of maturation, and is further enhanced by IL-4

Dendritic cells produce IL-12 both in response to microbial stimuli and to T cells, and can thus skew T cell reactivity toward a Th1 pattern. We investigated the capacity of dendritic cells to elaborate IL-12 with special regard to their state of maturation, different maturation stimuli, and its regulation by Th1/Th2-influencing cytokines. Monocyte-derived dendritic cells were generated with GM-CSF and IL-4 for 7 days, followed by another 3 days +/- monocyte-conditioned media, yielding mature (CD83(+)/dendritic cell-lysosome-associated membrane glycoprotein(+)) and immature (CD83(-)/dendritic cell-lysosome-associated membrane glycoprotein(-)) dendritic cells. These dendritic cells were stimulated for another 48 h, and IL-12 p70 was measured by ELISA. We found the following: 1) Immature dendritic cells stimulated with CD154/CD40 ligand or bacteria (both of which concurrently also induced maturation) secreted always more IL-12 than already mature dendritic cells. Mature CD154-stimulated dendritic cells still made significant levels (up to 4 ng/ml). 2) Terminally mature skin-derived dendritic cells did not make any IL-12 in response to these stimuli. 3) Appropriate maturation stimuli are required for IL-12 production: CD40 ligation and bacteria are sufficient; monocyte-conditioned media are not. 4) Unexpectedly, IL-4 markedly increased the amount of IL-12 produced by both immature and mature dendritic cells, when present during stimulation. 5) IL-10 inhibited the production of IL-12. Our results, employing a cell culture system that is now being widely used in immunotherapy, extend prior data that IL-12 is produced most abundantly by dendritic cells that are beginning to respond to maturation stimuli. Surprisingly, IL-12 is only elicited by select maturation stimuli, but can be markedly enhanced by the addition of the Th2 cytokine, IL-4.     

Organization of immature human immunodeficiency virus type 1

Immature retrovirus particles contain radially arranged Gag polyproteins in which the N termini lie at the membrane and the C termini extend toward the particle's center. We related image features to the polyprotein domain structure by combining mutagenesis with cryoelectron microscopy and image analysis. The matrix (MA) domain appears as a thin layer tightly associated with the inner face of the viral membrane, separated from the capsid (CA) layer by a low-density region corresponding to its C terminus. Deletion of the entire p6 domain has no effect on the width or spacing of the density layers, suggesting that p6 is not ordered in immature human immunodeficiency virus type 1 (HIV-1). In vitro assembly of a recombinant Gag polyprotein containing only capsid (CA) and nucleocapsid (NC) domains results in the formation of nonenveloped spherical particles which display two layers with density matching that of the CA-NC portion of immature HIV-1 Gag particles. Authentic, immature HIV-1 displays additional surface features and an increased density between the lipid bilayers which reflect the presence of gp41. The other internal features match those of virus-like particles.     

Alliance membership and kinship in wild male bottlenose dolphins (Tursiops aduncus) of southeastern Australia

Bottlenose dolphins are one of only a few mammalian taxa where the males are known to cooperate within their social group in order to maintain mating access to single females against other males. Male bonds in bottlenose dolphins have been hypothesized as evolving through kinship and associated inclusive fitness effects. In this study we tested whether individually identified male bottlenose dolphins preferentially associate and form alliances with kin in a small coastal resident population of southeastern Australia using a combination of behavioural data, genetic sexing, sequences of the mitochondrial DNA control region and nuclear microsatellite markers. Males generally associated significantly more often than expected with one to three other males, with whom they jointly herded females for mating. Associations and alliance membership were not associated with either maternal kinship or genetic relatedness. The majority of male pairs within alliances were randomly related, although high relatedness values were found between males of different alliances in the resident population. These findings indicate that mechanisms other than kin selection may be foremost in the development and maintenance of cooperation between male bottlenose dolphins.