Inhibition of insulin receptor phosphorylation by peptides derived from major histocompatibility complex class I antigens

Peptides from the alpha 1 region (residues 61-85) of the D and K molecules of the major histocompatibility complex class I antigens inhibit insulin-induced tyrosine kinase activity of the purified human insulin receptors (IRs) as measured both by autophosphorylation and IR-mediated substrate [poly(Glu,Tyr)] phosphorylation. Half-maximal effect of the Dk-(61-85) peptide on IR autophosphorylation is obtained at 1.2 microM, and almost complete inhibition of IR kinase activity is obtained at 10 microM peptide. The corresponding K kappa-(61-85) peptide has a significantly weaker effect on autophosphorylation. No such effects are observed with nine peptides of similar length, but unrelated to major histocompatibility complex class I antigens. Neither of the major histocompatibility complex class I-derived peptides has any effect on the constitutively active kinase of a genetically engineered cytoplasmic IR domain. Further, insulin binding to IR is unaltered in the presence of the major histocompatibility complex class I-derived peptides. The inhibitory activity of the peptides on insulin-induced IR phosphorylation facilitated the observation that IRs require insulin to become substrate for an independent tyrosine kinase. In the presence of an inhibitory peptide, the constitutively active cytoplasmic IR kinase domain only phosphorylates the intact IR in the presence of insulin. We conclude that the tyrosine kinase activity of IRs may be altered by peptide interaction at an allosteric site and, moreover, IRs require insulin to assume a conformation permitting phosphorylation by an independent kinase.     

Comparison of prostate volume, shape, and contouring variability determined from preimplant magnetic resonance and transrectal ultrasound images

PurposeTo compare preimplant prostate contours and contouring variability between magnetic resonance (MR) and transrectal ultrasound images.Methods and MaterialsTwenty-three patients were imaged using ultrasound (US) and MR before permanent brachytherapy treatment. Images were anonymized, randomized, and duplicated, and the prostate was independently delineated by five radiation oncologists. Contours were compared in terms of volume, dimensions, posterior rectal indentation, and observer variability. The Jaccard index quantified spatial overlap between contours from duplicated images.ResultsThe mean US/MR volume ratio was 0.99 ± 0.08 (p = 0.5). The width, height, and length ratios for the prostate were 0.98 ± 0.06 (p = 0.09), 0.99 ± 0.08 (p = 0.4), and 1.05 ± 0.14 (p = 0.1). Rectal indentation was larger on US by 0.18 mL (p = 0.01) and correlated with prostate volume (p < 0.01). MR and US interobserver variability in volume were similar at 3.5 ± 1.7 and 3.3 ± 1.9 mL (p = 0.6). Intraobserver variability was smaller on US at 1.4 ± 1.1 mL compared with MR at 2.4 ± 2.2 mL (p = 0.01). Local intraobserver variability was lower on US at the midgland slice (p < 0.01) but lower on MR at the base (p < 0.01) and apex (p < 0.01) slices.ConclusionsUS is comparable to MR for preimplant prostate delineation, with no significant difference in volume and dimensions. Rectal indentation because of the transrectal ultrasound probe was measurable, although the effects were small. Intraobserver variability was lower on US for the prostate volume but was lower on MR locally at the base and apex. However, the difference was not observed for the interobserver variability, which was similar between MR and US.     

Robotic harvest of the rectus abdominis muscle: a preclinical investigation and case report

In an attempt to decrease donor-site morbidity for rectus abdominis muscle harvest during free tissue transfer, we developed a technique of minimally invasive harvest. The da Vinci Surgical System (Intuitive Surgical, Sunnyvale, CA) was used in two cadavers for dissection and harvest of four rectus abdominis muscles. After the cadaver dissections were performed, the technique was used in a 30-year-old woman to harvest the left rectus abdominis muscle for free tissue transfer to a lower extremity defect. Four cadaver dissections for harvest of the rectus abdominis muscle using the da Vinci Surgical System were performed. In the cadavers and actual case, three ports (11 mm, 11 mm, and 15 mm) were used to access the abdominal cavity and perform the dissection. An additional 3 cm incision was used to remove the muscle from the abdominal cavity. The patient has not developed any surgical-site morbidity, including bulge or hernia in the 6 months postprocedure. Minimally invasive harvest of the rectus abdominis muscle is possible with the assistance of the da Vinci Surgical System. Potential benefits may include decreased surgical-site morbidity. Also, this may provide an approach to minimally invasive transperitoneal reconstruction.     

A new dimension: robotic reconstruction in plastic surgery

Background  

Robot-assisted surgery was first approved by the Federal Drug Administration in 1994. The robotic system has the advantages of three-dimensional visualization of the operating field, 7° range of motion, tremor elimination, 360°of freedom at 10-mm distance, and a comfortable, seated operating posture. The purpose of this paper is to present a new surgical tool, the robot, for use in reconstructive surgery.     

Birthweight,Childhood Body Mass Index,Height and Growth,and Risk of Polycystic Ovary Syndrome

IntroductionAdult obesity is linked with polycystic ovary syndrome (PCOS), but the importance of body size at ages before PCOS is diagnosed is unknown.ObjectiveTo investigate associations between a woman''s own birthweight, childhood body mass index (BMI), height and growth patterns in relation to her risk of PCOS.MethodsWe included 65,665 girls from the Copenhagen School Health Records Register, born in the period 1960–1996, with information on birthweight and measured weight and height at the ages of 7–13 years. Overweight was defined using International Obesity Task Force (IOTF) criteria. From the Danish National Patient Register, 606 women aged 15–50 years were identified. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated by Cox regression analysis.ResultsBirthweight was not associated with PCOS. At the age of 7–13 years, girls with overweight had a higher risk of developing PCOS than girls without overweight; HR 2.83 (95% CI 2.34–3.42) at age 7 years and 2.99 (95% CI 2.38–3.76) at age 13 years. Furthermore, girls with overweight at both 7 and 13 years had a higher risk of developing PCOS than girls without overweight or overweight at only one age. Height was positively associated with PCOS risk at all ages. Girls who were persistently tall or changed from tall to average height had a higher risk of developing PCOS than girls with average height growth.ConclusionOverweight and tall stature in childhood are positively associated with PCOS risk, but birthweight is not.     

Right ventricular strain predicts adverse outcomes in patients undergoing coronary artery bypass grafting

The International Journal of Cardiovascular Imaging - Patients undergoing coronary artery bypass grafting (CABG) face an elevated risk of heart failure (HF) and cardiovascular (CV) death. Detailed...     

A study of Chitosan and c‐di‐GMP as mucosal adjuvants for intranasal influenza H5N1 vaccine

Please cite this paper as: Svindland et al. (2012) A study of Chitosan and c‐di‐GMP as mucosal adjuvants for intranasal influenza H5N1 vaccine. Influenza and Other Respiratory Viruses 10.1111/irv.12056000(000), 000–000. Background  Highly pathogenic avian influenza A/H5N1 virus remains a potential pandemic threat, and it is essential to continue vaccine development against this subtype. A local mucosal immune response in the upper respiratory tract may stop influenza transmission. It is therefore important to develop effective intranasal pandemic influenza vaccines that induce mucosal immunity at the site of viral entry. Objectives  We evaluated the humoral and cellular immune responses of two promising mucosal adjuvants (Chitosan and c‐di‐GMP) for intranasal influenza H5N1 vaccine in a murine model. Furthermore, we evaluated the concept of co‐adjuvanting an experimental adjuvant (c‐di‐GMP) with chitosan. Methods  BALB/c mice were intranasally immunised with two doses of subunit NIBRG‐14 (H5N1) vaccine (7·5, 1·5 or 0·3 μg haemagglutinin (HA) adjuvanted with chitosan (CSN), c‐di‐GMP or both adjuvants. Results  All adjuvant formulations improved the serum and local antibody responses, with the highest responses observed in the 7·5 μg HA CSN and c‐di‐GMP‐adjuvanted groups. The c‐di‐GMP provided dose sparing with protective single radial haemolysis (SRH), and haemagglutination inhibition (HI) antibody responses found in the 0·3 μg HA group. CSN elicited a Th2 response, whereas c‐di‐GMP induced higher frequencies of virus‐specific CD4⁺ T cells producing one or more Th1 cytokines (IFN‐γ⁺, IL‐2⁺, TNF‐α⁺). A combination of the two adjuvants demonstrated effectiveness at 7·5 μg HA and triggered a more balanced Th cytokine profile. Conclusion  These data show that combining adjuvants can modulate the Th response and in combination with ongoing studies of adjuvanted intranasal vaccines will dictate the way forward for optimal mucosal influenza vaccines.     

Integrated view of genome structure and sequence of a single DNA molecule in a nanofluidic device

We show how a bird’s-eye view of genomic structure can be obtained at ∼1-kb resolution from long (∼2 Mb) DNA molecules extracted from whole chromosomes in a nanofluidic laboratory-on-a-chip. We use an improved single-molecule denaturation mapping approach to detect repetitive elements and known as well as unique structural variation. Following its mapping, a molecule of interest was rescued from the chip; amplified and localized to a chromosome by FISH; and interrogated down to 1-bp resolution with a commercial sequencer, thereby reconciling haplotype-phased chromosome substructure with sequence.Despite the sequencing of thousands of genomes (1), no human genome—reference or individual—has been described to completion (2): gaps remain in the genome reference sequence and there is a discontinuity between the resolution of next-generation sequencing and the resolution of cytogenetics. This gap leaves structure in the kilobase-to-megabase range partly unmapped. The nature and extent of highly repetitive regions—the centromeres, rDNA on the short arms of acrocentric chromosomes, the long arm of the Y chromosome—remain to be fully delineated, as do the sequences embedded in these regions. Sequencing of individual genomes (3) has also revealed that chromosome-scale amounts of sequence do not align to the human reference genome (4, 5), suggesting that substantial levels of sequence insertions are specific to individuals or subpopulations. Structural variation (SV) comprising rearrangement, loss, or gain of genomic regions is increasingly linked to phenotype and disease (6, 7). In cancer genomes, SV can be extreme (8) and difficult to deconvolve.All types and scales of SV pervade the human genome, but a single approach cannot capture them all (9). For example, though unbalanced SV can be readily ascertained by array technology, balanced SV cannot; a comprehensive analysis by paired-end sequencing is challenging and cost-prohibitive. Single-molecule optical mapping (10–13) facilitates assembly of genomes and detects SV, but haplotype phase is not preserved, because it requires construction of a consensus map from many molecules. These molecules cannot be recovered for further analysis, requiring larger amounts of sample for analysis, which may not be available, e.g., single-cell sequencing and clinical samples. An attempt to combine haplotyping and sequencing on Illumina flow cells was limited to sequencing only at the ends of short fragments (≤8 kb) (14).Microfluidic laboratory-on-a-chip devices have been used to separate individual chromosomes and extract genomic DNA (15, 16), enabling haplotype-phased genotype and sequence to be obtained. Meanwhile, laboratory-on-a-chip systems incorporating nanofluidics have been used to stretch and map DNA (17–19), but their application to detecting SV has remained theoretical due to technical limitations of the designs used. Existing platforms either do not stretch and hold DNA well enough to consistently produce accurate maps from a single molecule (20, 21), or they use inefficient labeling chemistry (22) and consequently cannot differentiate between poor matches and actual structural variation within a single molecule. These platforms also require purified input DNA, which is typically sheared during handling steps, cannot produce maps longer than a few hundred kilobases, and cannot readily recover the mapped DNA molecules to perform conventional genomic analysis. Finally, although confinement in nanochannels can provide high stretching under extreme buffer conditions (23), it is desirable to achieve full stretching independently of buffer composition.Here we describe a laboratory-on-a-chip design that overcomes these technical limitations and a procedure that offers an integrated view of human genome structure. By integrating a nanofluidic system with elongation flow into a laboratory-on-a-chip, (i) haplotype-phased chromosome substructures can be visualized on single megabase-scale molecules, (ii) structural variation ranging in size from a few kilobases to megabases can then be detected, (iii) our experimental maps can be compared with theoretical maps based on different genome assemblies, and variations can be detected, and (iv) interrogation of the same molecule can be zoomed out to the cytogenetic level and zoomed in to the sequence level.