Glucose correlation with light scattering patterns--a novel method for non-invasive glucose measurements

To correlate occlusion red near-infrared spectroscopy technology with intravenous and interstitial glucose levels, occlusion red near-infrared spectroscopy and glucose levels were measured in five subjects with diabetes mellitus during a stepped hyperinsulinemic hypoglycemic clamp. Validation was achieved using a standard error grid and linear correlations. During hyperinsulinemic hypoglycemic clamp linear correlation was significant at r = 0.836, and the intercept was 43.3 mg/dL. Of the glucose measurements, 94.3% were assigned to zones A and B of the standard error grid, the zones of the greatest therapeutic relevance. Expected interference from serum triglycerides, catecholamines, and cortisol was not apparent. These results demonstrate the applicability of occlusion red near-infrared spectroscopy for in vivo glucose monitoring. The technology has implications for continuous non-invasive glucose sensing.     

Parenteral administration of an activating monoclonal antibody to the alpha1beta1 integrin in dogs

In mice, monoclonal antibody (mAb) to the alpha1 integrin abrogate gastro-intestinal damage during graft-versus-host-disease (GVHD), suggesting anti alpha1 mAb as candidates for treatment in humans as well. Our current data show that one such reagent, mAb 1B3.1, when immobilized to plastic wells via rabbit- anti murine (ram) immunoglobulin (Ig) induces a protein kinase-dependent spreading of activated human T cells. Furthermore, it significantly increases the proliferative response, and expression of interleukin-2 (IL-2) receptors (R) and CD69, of resting T cells, expressing minimal integrin on the cell surface, to sub-optimal stimulation by anti-CD3 mAb. We found, in addition, that mAb 1B3.1 a) immuno-precipitates alpha1beta1 integrins from cell-surface iodinated canine epithelial cells b) is highly reactive with canine T cells after their activation and c) inhibits adhesion of canine T cells to collagen IV. Despite the potential ability of the mAb to co-activate T cells in vitro, two dogs that received 4 injections of 0.5-0.3 mg/Kg of mAb 1B3.1 remained healthy, developing only marginal transient lymphopenia. Injection of 0.75mg/Kg in a third dog induced a more marked lymphopenia, and an additional dose of 1.0 mg/Kg 2 weeks later was followed by gastrointestinal hemorrhage. importantly, the lymphopenia was associated with a greater and more persistent decrease of CD8+ than of CD4+ T cells, leading to an increase in the CD4/CD8 ratio 24 hours after the injection. Thus, despite it's co-activating effects in vitro, administration of this mAb in vivo is feasible when appropriately dosed, and may have immuno-modulatory effects.     

Remediation of memory disorders in schizophrenia

BACKGROUND: Memory deficits are commonly experienced by patients with schizophrenia, often persist even after effective psychotropic treatment of psychotic symptoms and have been demonstrated to interfere with many aspects of successful psychiatric rehabilitation. Because of significant impact on functional outcome, effective remediation of cognitive deficits has been increasingly cited as an essential component of comprehensive treatment. Efforts to remediate memory deficits have met with circumscribed success, leaving uncertain whether schizophrenia patients can be taught, without experimental induction, independently to employ semantic encoding or a range of other mnemonic techniques. METHOD: We examined the feasibility of using memory and problem solving teaching techniques developed within educational psychology--techniques which promote intrinsic motivation and task engagement through contextualization and personalization of learning activities--to remediate memory deficits in a group of in-patients with chronic schizophrenia spectrum disorders. RESULTS: Although our memory remediation group significantly improved on the memory remediation task, they did not make greater gains on measures of immediate paragraph recall or list learning than the control groups. CONCLUSIONS: Targeted remediation of memory appears to yield task specific improvement but the gains do not generalize to other memory tasks. Subjects receiving memory remediation failed to independently activate mnemonic encoding strategies learned and used successfully within training tasks to other general measures of verbal learning and memory.     

Partial penetrance and phenotypic variability of aplasia of lacrimal and salivary glands caused by a novel FGF10 donor splice-site mutation

Thirteen affected individuals of six generations of a single kindred presented with epiphora evident from infancy. Physical exam and Schirmer test revealed variable expression of tear deficiency, congenital punctal atresia, and dry mouth with multiple caries, without concomitant abnormalities of the ears or digits, commensurate with a diagnosis of aplasia of the lacrimal and salivary glands (ALSG). Reconstruction of the upper lacrimal drainage system was performed in some of the affected individuals. Genetic analysis, testing six affected individuals and three non-affected family members, identified a single novel heterozygous splice-site variant, c.429 + 1, G > T in fibroblast growth factor 10 (FGF10) (NM_004465.1), segregating throughout the family as expected for dominant heredity. RT-PCR assays of HEK-293 cells transfected with wild type or mutant FGF10 demonstrated that the variant causes skipping of Exon 2. Notably, individuals sharing the same variant exhibited phenotypic variability, with unilateral or bilateral epiphora, as well as variable expression of dry mouth and caries. Moreover, one of the variant carriers had no ALSG-related clinical findings, demonstrating incomplete penetrance. While coding mutations in FGF10 are known to cause malformations in the nasolacrimal system, this is the second FGF10 splice-site variant and the first donor-site variant reported to cause ALSG. Thus, our study of a unique large kindred with multiple affected individuals heterozygous for the same FGF10 variant highlights intronic splice-site mutations and phenotypic variability/partial penetrance in ALSG.     

Endotoxin-induced shedding of viable uroepithelial cells is an antimicrobial defense mechanism.

ICR mice were infected intravesically with a virulent (7343) or a nonvirulent (U+) Escherichia coli strain. The U+ strain induced considerably more shedding of uroepithelial cells than did the 7343 strain. The stimulus for this shedding was shown to be associated with lipopolysaccharide and was abrogated by pretreatment with aprotinin. Desquamation commenced within 1 h postinjection, and the cells that were shed proved to be viable. Comparison of C3H/HeJ and C3H mice revealed that only the latter responded to shedding inducers. However, C3H/HeJ mice succumbed to a systemic infection on injection of 10(6) U+ cells intravesically, whereas other mouse strains required a 100-fold dose of bacteria for this effect. Since the first stage of a bacterial infection entails adherence of the microbes to epithelial cells, inducible shedding is an antimicrobial defense mechanism.     

Entamoeba histolytica DNA methyltransferase (Ehmeth) is a nuclear matrix protein that binds EhMRS2, a DNA that includes a scaffold/matrix attachment region (S/MAR)

The protozoan parasite Entamoeba histolytica express a cytosine-5 DNA methyltransferase (Ehmeth) that belongs to the DNMT2 protein family. The biological function of members of this DNMT2 family is unknown. In the present study, we have demonstrated that Ehmeth is a nuclear matrix protein. Indeed, we showed by south-western analysis and yeast one-hybrid system that Ehmeth binds to EhMRS2, a DNA element which contains the eukaryotic consensus scaffold/matrix attachment regions (S/MAR) bipartite recognition sequences. S/MARs have been implicated in a variety of important functions, such as genome organization and gene expression. The methylation status of cytosine located within EhMRS2 was analyzed by bisulfite genomic sequencing. We observed the presence of methylated cytosine within the 3'-end of EhMRS2. These data provide the first evidence that a member of the DNMT2 family interacts with a S/MAR containing DNA element.     

The Legionella pneumophila GacA homolog (LetA) is involved in the regulation of icm virulence genes and is required for intracellular multiplication in Acanthamoeba castellanii

Legionella pneumophila, the causative agent of legionnaires' disease, is a broad-host-range facultative intracellular pathogen. Thus far, 24 genes (icm/dot genes) required for L. pneumophila intracellular growth, have been discovered. In this study, a deletion substitution was constructed in the L. pneumophila homolog of the gacA response regulator (letA) and its involvement in L. pneumophila pathogenicity and icm/dot gene expression was characterized. The letA mutant constructed had no intracellular growth defect when analyzed in HL-60 derived human macrophages, but it was found to be severely attenuated for intracellular growth in the protozoan host Acanthamoeba castellanii. The growth defect in amoebae was fully complemented by introducing the L. pneumophila letA gene on a plasmid. In addition, the LetA regulator was found to be involved in the expression of three icm genes (icmT, icmP and icmR). The level of expression of the icmT::lacZ and icmR::lacZ fusions was found to be higher, while the level of expression of the icmP::lacZ fusion was found to be lower when analyzed in the letA mutant strain, in comparison to the wild-type strain. We concluded that LetA has a moderate effect on icm/dot gene expression, but it probably plays a major role in the expression of L. pneumophila genes required for intracellular growth in protozoan hosts. A similar host specific phenotype was previously described for the RpoS sigma factor and the type II general secretion system of L. pneumophila.