No evidence of mineralization abnormalities in iliac bone of premenopausal women with type 2 diabetes mellitus

Objectives:Patients with type-2 diabetes mellitus (T2DM) have increased risk for bone fractures which points towards impaired bone quality.Methods:We measured bone mineralization density distribution (BMDD) and osteocyte lacunae section (OLS) characteristics based on quantitative backscattered electron images of transiliac biopsy samples from n=26 premenopausal women with T2DM. Outcomes were compared to those from reference cohorts as well as between T2DM subgroups defined by clinical characteristics.Results:Comparison to references did not reveal any differences in BMDD (all p>0.05) but a lowered OLS-density in cancellous bone in T2DM (-14.9%, p<0.001). Neither BMDD nor OLS-characteristics differed in T2DM subgroups defined by HbA1c (<7% versus >7%). The average degree of bone mineralization (CaMean) was higher (0.44 wt%Ca in T2DM, 0.30 wt%Ca in reference) and consistently the calcium concentration between the tetracycline double labels (CaYoung) was higher (0.76 wt%Ca, all p<0.001) in cancellous versus cortical bone.Conclusions:Our findings suggest that bone matrix mineralization was neither affected by the presence nor by the glycemic control of T2DM in our study cohort. The intra-individual differences between cancellous and cortical bone mineralization gave evidence for differences in the time course of the early mineralization process in these compartments in general.     

Molecular analysis of Gaucher disease: distribution of eight mutations and the complete gene deletion in 27 patients from Germany

Gaucher disease is the most common lysosomal storage disease with a high prevalence in the Ashkenazi Jewish population but it is also present in other populations. The presence of eight mutations (1226G, 1448C, IVS2+1, 84GG, 1504T, 1604T, 1342C and 1297T) and the complete deletion of the β-glucocerebrosidase gene was investigated in 25 unrelated non-Jewish patients with Gaucher’s disease in Germany. In the Jewish population, three of these mutations account for more than 90% of all mutated alleles. In addition, relatives of two patients were included in our study. Restriction fragment length polymorphism analysis and sequencing of PCR products obtained from DNA of peripheral blood leukocytes was performed for mutation analysis. Gene deletion was detected by comparison of radioactively labelled PCR fragments of both the functional β-glucocerebrosidase gene and the pseudogene. Among the unrelated patients, 50 alleles were investigated and the mutations identified in 35 alleles (70%), whereas 15 alleles (30%) remained unidentified. The most prevalent mutation in our group of patients was the 1226G (370^Asn→Ser) mutation, accounting for 18 alleles (36%), followed by the 1448C (444^Leu→Pro) mutation, that was found in 12 alleles (24%). A complete gene deletion was present in two alleles (4%). The IVS1+2 (splicing mutation), the 1504T (463^Arg→Cys) as well as the 1342C (409^Asp→His) mutations were each present in one allele (2%). None of the alleles carried the 84GG (frameshift), 1604A (496^Arg→His) or the 1297T (394^Val→Leu) mutation. This distribution is different from the Ashkenazi Jewish population but is similar to other Caucasian groups like the Spanish and Portuguese populations. Our results confirm the variability of mutation patterns in Gaucher patients of different ethnic origin. All patients were divided into nine groups according to their genotype and their clinical status was related to the individual genotype. Genotype/phenotype characteristics of the 1226G, 1448C, and 1342C mutations of previous studies were confirmed by our results. Received: 19 November 1996 / Revised: 29 January 1997     

Report on the Polycystididae (Rhabdocoela, Kalyptorhynchia) from Australia, with the Description of Twelve New Species and Six New Genera

Twelve new species of Polycystididae Graff, 1905 are described from the Australian east coast. Nine of them could not be placed in any of the existing genera, and therefore six new genera are erected. Alchoides n. gen. differs from all other polycystidid genera by the presence of a bundle of glands that opens into the distal part of the male atrium (accessory vesicle type V). Two species are included in the genus, A. alchoides n. sp. and A. dittmannae n. sp., which differ from each other in the shape of the stylet. Ametochus gehrkei n. gen n. sp. can be distinguished from other polycystidids by the presence of a prostate vesicle type III associated with a prostate stylet type III, combined with the presence of an accessory stylet type III, while a prostate stylet type II is lacking. Typical for Arrawarria inexpectata n. gen n. sp. is the combined presence of an armed cirrus with a prostate vesicle type II connected to a prostate stylet type II. Two species are assigned to the new genus Duplexostylus n. gen.: D. rowei n. sp. and D. winsori n. sp. These two species have two unique features: a prostate vesicle type IV directly connected to a prostate stylet type III and an asymmetrical septum that surrounds the proximal part of the male atrium. They can be distinguished from each other by differences in the detailed construction of their stylets. Two new species are placed in the new genus Stradorhynchus n. gen.: S. caecus n. sp. and S. terminalis n. sp. They have unpaired gonads and a prostate vesicle type IV connected to a prostate stylet type IV, which combination of characters makes them unique within the Polycystididae. The two species differ from each other in the shape and size of the stylet. Triaustrorhynchus armatus n. gen., n. sp. is the first species of the Polycystididae to have three types of stylet in the male atrium: a prostate stylet type II, a prostate stylet type III and an accessory stylet type III. Three new species could be placed in existing genera: Cincturorhynchus monaculeus n. sp., Paraustrorhynchus caligatus n. sp. and Polycystis australis n. sp. All three differ from their congeners in the form and dimensions of their stylets. All newly described species are discussed, giving their similarities and differences with resembling species. Austrorhynchus hawaiiensis Karling, 1977 is reported for the first time in Australia, and the Australian population is compared with populations from other regions. The presence of Gyratrix hermaphroditus Ehrenberg, 1831, one new species of Paulodora Marcus, 1948 and a new genus of Typhlopolycystidinae Evdonin, 1977 is mentioned.     

The role of adhesion molecules and chemokine receptor CXCR4 (CD184) in small cell lung cancer

Small-cell lung cancer (SCLC) is a particularly aggressive form of lung cancer. Responsible for this highly malignant phenotype is an early and widespread metastasis with a high propensity of SCLC cells for bone marrow involvement and the ability to develop resistance against chemotherapeutic agents. Tumor cell migration and metastasis share many similarities with leukocyte trafficking, which is critically regulated by chemokines and adhesion molecules. There is growing evidence that the chemokine stromal derived factor-1 (SDF-1/CXCL12) and its receptor CXCR4 (CD184) regulate migration and metastasis of a variety of cancers including SCLC. SCLC cells express high levels of functional CXCR4 receptors. Engagement of CXCR4 by CXCL12 leads to an upregulation of integrin-mediated adhesion in SCLC and other tumor cells. Activation of CXCR4 chemokine receptors and integrins on SCLC cells promotes adhesion to accessory cells (such as stromal cells) and extracellular matrix molecules within the tumor microenvironment. These adhesive interactions result in an increased resistance of SCLC cells to chemotherapy. As such, inhibitors of the CXCR4/CXCL12 axis and/or integrin activation may increase the chemosensitivity of SCLC cells and lead to new therapeutic avenues for patients with SCLC.     

Simplified, Accurate Method for Antibiotic Assay of Clinical Specimens

Large glass plates are used for this modified agar-well diffusion assay method, allowing up to 81 replications on a single plate. With a specially designed agar punch, it is possible to prepare the small agar wells very quickly. The saving in serum resulting from fewer replications of standards with the large plates, and the small volume of the agar wells, makes it economically feasible to use pooled human serum for the standard antibiotic solutions. Methods are described for preparing the standard solutions, and for providing controls for the deterioration of standards and unknowns. Procedures for preparing and maintaining the commonly used assay organisms are presented. Serum specimens are tested directly rather than diluting them to a narrow range of antibiotic concentrations. This is possible because of a procedure for calculations that recognizes the curvilinear relationship between zone sizes and antibiotic concentrations. Adaptation of this method to a number of the commonly used antibiotics is described. With this method, it has been possible to test large numbers of clinical specimens in a minimal time, and with accuracy consistently better than 10%.     

Mechanistic aspects of CPP-mediated intracellular drug delivery: Relevance of CPP self-assembly

In recent years, cell-penetrating peptides have proven to be an efficient intracellular delivery system. The mechanism for CPP internalisation, which first involves interaction with the extracellular matrix, is followed in most cases by endocytosis and finally, depending on the type of endocytosis, an intracellular fate is reached. Delivery of cargo attached to a CPP requires endosomal release, for which different methods have recently been proposed. Positively charged amino acids, hydrophobicity and/or amphipathicity are common to CPPs. Moreover, some CPPs can self-assemble. Herein is discussed the role of self assembly in the cellular uptake of CPPs. Sweet Arrow Peptide (SAP) CPP has been shown to aggregate by CD and TEM (freeze-fixation/freeze-drying), although the internalised species have yet to be identified as either the monomer or an aggregate.