No evidence for DUP25 in patients with panic disorder using a quantitative real-time PCR approach

A duplication of chromosome 15q24-q26 (DUP25) has been reported to be associated with anxiety disorders. We tested for the presence of DUP25 in a sample of 50 patients with panic disorder and 50 controls using a quantitative real-time PCR approach. Contrary to the original finding, our results were compatible with the absence of DUP25, and no significant difference could be detected between patients and controls (P=1.0). Thus, our study does not support the hypothesis of an involvement of DUP25 in panic disorder.     

Mutation patterns and structural correlates in human immunodeficiency virus type 1 protease following different protease inhibitor treatments

Although many human immunodeficiency virus type 1 (HIV-1)-infected persons are treated with multiple protease inhibitors in combination or in succession, mutation patterns of protease isolates from these persons have not been characterized. We collected and analyzed 2,244 subtype B HIV-1 isolates from 1,919 persons with different protease inhibitor experiences: 1,004 isolates from untreated persons, 637 isolates from persons who received one protease inhibitor, and 603 isolates from persons receiving two or more protease inhibitors. The median number of protease mutations per isolate increased from 4 in untreated persons to 12 in persons who had received four or more protease inhibitors. Mutations at 45 of the 99 amino acid positions in the protease-including 22 not previously associated with drug resistance-were significantly associated with protease inhibitor treatment. Mutations at 17 of the remaining 99 positions were polymorphic but not associated with drug treatment. Pairs and clusters of correlated (covarying) mutations were significantly more likely to occur in treated than in untreated persons: 115 versus 23 pairs and 30 versus 2 clusters, respectively. Of the 115 statistically significant pairs of covarying residues in the treated isolates, 59 were within 8 A of each other-many more than would be expected by chance. In summary, nearly one-half of HIV-1 protease positions are under selective drug pressure, including many residues not previously associated with drug resistance. Structural factors appear to be responsible for the high frequency of covariation among many of the protease residues. The presence of mutational clusters provides insight into the complex mutational patterns required for HIV-1 protease inhibitor resistance.     

Ultrasound indentation of bovine knee articular cartilage in situ

We have earlier developed a handheld ultrasound indentation instrument for the diagnosis of articular cartilage degeneration. In ultrasound indentation, cartilage is compressed with the ultrasound transducer. Tissue thickness and deformation are calculated from the A-mode ultrasound signal and the stress applied is registered with the strain gauges. In this study, the applicability of the ultrasound indentation instrument to quantify site-dependent variation in the mechano-acoustic properties of bovine knee cartilage was investigated. Osteochondral blocks (n=6 per site) were prepared from the femoral medial condyle (FMC), the lateral facet of the patello-femoral groove (LPG) and the medial tibial plateau (MTP). Cartilage stiffness (dynamic modulus, E(dyn)), as obtained with the ultrasound indentation instrument in situ, correlated highly linearly (r=0.913, p<0.01) with the values obtained using the reference material-testing device in vitro. Reproducibility (standardized coefficient of variation) of the ultrasound indentation measurements was 5.2%, 1.7% and 3.1% for E(dyn), ultrasound reflection coefficient of articular surface (R) and thickness, respectively. E(dyn) and R were site dependent (p<0.05, Kruskall-Wallis H test). E(dyn) was significantly higher (p<0.05, Kruskall-Wallis Post Hoc test) in LPG (mean+/-SD: 10.1+/-3.1MPa) than in MTP (2.9+/-1.4MPa). In FMC, E(dyn) was 4.6+/-1.3MPa. R was significantly (p<0.05) lower at MTP (2.0+/-0.7%) than at other sites (FMC: 4.2+/-0.9%; LPG: 4.4+/-0.8%). Cartilage glycosaminoglycan concentration, as quantified with the digital densitometry, correlated positively with E(dyn) (r=0.678, p<0.01) and especially with the equilibrium Young's modulus (reference device, r=0.874, p<0.01) but it was not associated with R (r=0.294, p=0.24). We conclude that manual measurements are reproducible and the instrument may be used for detection of cartilage quality in situ. Especially, combined measurement of thickness, E(dyn) and R provides valuable diagnostic information on cartilage status.     

Plasma kinetics of VLDL and HDL apoC-I in normolipidemic and hypertriglyceridemic subjects

ApoC-I has several different lipid-regulating functions including, inhibition of receptor-mediated uptake of plasma triglyceride-rich lipoproteins, inhibition of cholesteryl ester transfer activity, and mediation of tissue fatty acid uptake. Since little is known about the rate of production and catabolism of plasma apoC-I in humans, the present study was undertaken to determine the plasma kinetics of VLDL and HDL apoC-I using a primed constant (12 h) intravenous infusion of deuterium-labeled leucine. Data were obtained for 14 subjects: normolipidemics (NL, n = 4), hypertriglyceridemics (HTG, n = 4) and combined hyperlipidemics (CHL, n = 6). Plasma VLDL triglyceride (TG) levels were 0.59 +/- 0.03, 4.32 +/- 0.77 (P < 0.01 vs. NL), and 2.20 +/- 0.39 mmol/l (P < 0.01 vs. NL), and plasma LDL cholesterol (LDL-C) levels were 2.34 +/- 0.22, 2.48 +/- 0.26, and 5.35 +/- 0.48 mmol/l (P < 0.01 vs. NL), respectively. HTG and CHL had significantly (P < 0.05) increased levels of total plasma apoC-I (12.5 +/- 1.2 and 12.4 +/- 1.3 mg/dl, respectively) versus NL (7.9 +/- 0.6 mg/dl), due to significantly (P < 0.01) elevated levels of VLDL apoC-I (5.8 +/- 0.8 and 4.5 +/- 0.8 vs. 0.3 +/- 0.1 mg/dl). HTG and CHL also had increased rates of VLDL apoC-I transport (i.e., production) versus NL: 2.29 +/- 0.34 and 3.04 +/- 0.53 versus 0.24 +/- 0.11 mg/kg.day (P < 0.01), with no significant change in VLDL apoC-I residence times (RT): 1.16 +/- 0.12 versus 0.69 +/- 0.06 versus 0.74 +/- 0.17. Although HDL apoC-I concentrations were not significantly lower in HTG and CHL versus NL, HDL apoC-I rates of transport were inversely related to plasma and VLDL-TG levels (r = -0.63 and -0.62, respectively, P < 0.05). Our results demonstrate that increased levels of plasma and VLDL apoC-I in hypertriglyceridemic subjects (with or without elevated LDL-C levels) are associated with increased levels of plasma VLDL apoC-I production.     

Total synthesis and evaluation of lamellarin alpha 20-Sulfate analogues

In order to explore the influence of sulfate groups on the bioactivity profiles of marine alkaloids of the lamellarin class, three such alkaloids, lamellarin alpha, lamellarin alpha 13,20-disulfate and lamellarin H, were synthesized and their activities against HIV-1 integrase and cancer cell lines were compared with those of lamellarin alpha 20-sulfate, which is a selective inhibitor of HIV-1 integrase. Lamellarin alpha does not inhibit HIV-1 integrase but shows moderate cytotoxicity with good cell line selectivity. Lamellarin alpha 13,20-disulfate is a moderate inhibitor of both HIV-1 integrase and cancer cell lines. Lamellarin H is a more potent inhibitor of HIV-1 integrase but lacked the specificity required to be medicinally useful.     

Mechanism of formation of a productive molten globule form of barstar

Structural analysis of the initial steps in protein folding is difficult because of the swiftness with which these steps occur. Hence, the link between initial polypeptide chain collapse and formation of secondary and other specific structures remains poorly understood. Here, an equilibrium model has been developed for characterizing the initial steps of folding of the small protein barstar, which lead to the formation of a productive molten globule in the folding pathway. In this model, the high-pH-unfolded form (D form) of barstar, which is shown to be as unstructured as the urea-denatured form, is transformed progressively into a molten globule B form by incremental addition of the salt Na(2)SO(4) at pH 12. At very low concentrations of Na(2)SO(4), the D form collapses into a pre-molten globule (P) form, whose volume exceeds that of the native (N) state by only 20%, and which lacks any specific structure as determined by far- and near-UV circular dichroism. At higher concentrations of Na(2)SO(4), the P form transforms into the molten globule (B) form in a highly noncooperative transition populated by an ensemble of at least two intermediates. The B form is a dry molten globule in which water is excluded from the core, and in which secondary structure develops to 65% and tertiary contacts develop to 40%, relative to that of the native protein. Kinetic refolding experiments carried out at pH 7 and at high Na(2)SO(4) concentrations, in which the rate of folding of the D form to the N state is compared to that of the B form to the N state, indicate conclusively that the B form is a productive intermediate that forms on the direct pathway of folding from the D form to the N state.     

Inheritance of pyriproxyfen resistance in the whitefly, Bemisia tabaci (Q biotype)

The inheritance of resistance to pyriproxyfen, an insect growth regulator (a juvenoid, with ovicidal and larvicidal activities), was studied in the whitefly Bemisia tabaci (Gennadius). Two parental strains, both belonging to Q biotype, were assayed with pyriproxyfen; a susceptible strain (ALM-1) originating from Spain and a pyriproxyfen-resistant one (Pyri-R) from Israel. The resistance ratio between the two parental strains was approximately 7,000-fold. Concentration-mortality lines for F(1) heterozygous females from reciprocal crosses (SS female symbol X R male symbol and RR female symbol X S male symbol ) were derived by statistical modelling and proved intermediate to those of the parents. The pooled degree of dominance from both reciprocal crosses was +0.26, indicating that resistance was incompletely or partially dominant. Mortality curves for F(2) males produced by virgin F(1) heterozygous females displayed a broad plateau at 50% mortality, indicating that resistance to pyriproxyfen in B. tabaci is conferred primarily by a mutant allele at a single locus. The role of arrhenotoky in influencing the mode of inheritance of resistance, and its selection in field populations, is discussed.     

Structure of 2',5'-linked tetraribonucleotide loops: a novel RNA motif

We report on the three dimensional structure of an RNA hairpin containing a 2',5'-linked tetraribonucleotide loop, namely, 5'-rGGAC(UUCG)GUCC-3' (where UUCG = U(2'p5')U(2'p5')C(2'p5')G(2'p5')). We show that the 2',5'-linked RNA loop adopts a conformation that is quite different from that previously observed for the native 3',5'-linked RNA loop. The 2',5'-RNA loop is stabilized by (a) U:G wobble base pairing, with both bases in the anti conformation, (b) extensive base stacking, and (c) sugar-base contacts, all of which contribute to the extra stability of this hairpin structure.