Utility of software analysis of esophageal manometry studies in patients with aperistalsis.

Esophageal manometry is the gold standard for the diagnosis of esophageal aperistalsis. There is computer software that analyzes peristalsis on esophageal manometry, but this automated analysis has not been formally evaluated. Our primary aim was to evaluate the software analysis of esophageal aperistalsis by esophageal manometry in patients diagnosed with aperistalsis by an experienced clinician. Esophageal manometry studies from January 2006 to November 2007 were retrospectively reviewed for evidence of aperistalsis by an experienced clinician. All studies demonstrating aperistalsis were selected for further review. The automated analysis performed by our software program for each study was recorded. Agreement between the automated analysis and the clinician was measured by the proportion of agreement on the absence of peristalsis. Eighty-seven of the 962 esophageal manometry studies reviewed demonstrated aperistalsis. The automated analysis reported esophageal body peristalsis with wet swallows in 66 out of 87 patients (75.9%). In these patients, the software analyzed an average of 34.2% of the wet swallows as peristaltic. The agreement between the clinician's review and software analysis of aperistalsis was 24.1%. These data suggest there is poor agreement between the automated analysis of peristalsis and that of an experienced reviewer. Automated analysis cannot be relied upon in the diagnostic evaluation of esophageal aperistalsis as it overestimates the presence of peristalsis and may lead to incorrect diagnoses and management strategies.

Analysis of herpes simplex virus-induced mRNA destabilizing activity using an in vitro mRNA decay system.

Most host mRNAs are degraded soon after infection of cells with herpes simplex virus type 1 (HSV-1). This early shutoff or early destabilization response is induced by a virion component, the virion host shutoff (vhs) protein. HSV-1 mutants, vhs1 and vhs-delta Sma, which produce defective or inactive vhs protein, fail to induce early shutoff. We have used an in vitro mRNA decay system to analyze the destabilization process. Polysomes from uninfected human erythroleukemia cells, used as a source of target mRNAs, were mixed with polysomes or with post-polysomal supernatant (S130) from HSV-1- or mock-infected murine erythroleukemia cells. Normally stable gamma-globin mRNA was destabilized by approximately 15-fold with S130 from wild-type virus-infected cells but was not destabilized with S130 from mock-infected cells or from cells infected with either of the two HSV mutants. The virus-induced destabilizing activity had no significant effect on the in vitro half-lives of two normally unstable mRNAs, histone and c-myc. No destabilizing activity was detected in polysomes from infected cells. We conclude that a virus-induced destabilizer activity can function in vitro, is located in the S130 of infected cells, and accelerates the decay rates of some, but not all, polysome-associated host mRNAs.

Amino acid 61 is a determinant of sensitivity of rap proteins to the ras GTPase activating protein.

The GTPase activating protein (ras-GAP) has been shown to interact with p21ras at a domain defined by amino acids 32-40. The sequences of the rap family of ras related proteins (including a suppressor of ras transformation Krev-1/rap1A) are identical to ras in this region. Incubation of rap1A protein with ras-GAP does not accelerate the rate of GTP hydrolysis by p21rap1A. Rap proteins have threonine at amino acid 61, whereas ras proteins have glutamine at this site and mutation to threonine reduces the intrinsic GTPase of p21ras. We have, therefore, mutated thr61 of p21rap1A to glutamine and shown that ras-GAP is now able to accelerate the rate of hydrolysis of GTP. This demonstrates that ras-GAP can interact with rap and that the sensitivity to ras-GAP is determined in part by the amino acid at codon 61.

Left-handed DNA in restriction fragments and a recombinant plasmid.

Circular dichroism and 31P-NMR on synthetic oligomers of (dC-dG) inserted within DNA restriction fragments indicate that the right-handed B-structure can exist in close proximity to the left-handed Z-structure. Also, this salt-induced transition to Z-form in a small (dC-dG) segment (1.3%) of a recombinant plasmid markedly influenced the supercoil of the plasmid. These observations have implications for the postulated role of naturally occurring related simple sequences in the regulation of gene activity.

Conformation of mononucleotides and dinucleoside monophosphates. P[H] and H[H] nuclear Overhauser effects.

The phosphorus-proton nuclear Overhauser effect (NOE) was used to investigate the quantitative distribution of rotamers about the C3'--O3' bond (phi') of 3'-AMP and 2',3'-cyclic-CMP and the C4'--C5', C5'--O5' bonds (psi, phi) of 5'-AMP. Phosphorus-proton and proton-proton NOE's were used to provide a qualitative insight into the backbone conformation and the glycosyl angle torsions of adenosylyl-(3' leads to 5')-adenosine (ApA). The major psi rotamer in 5'-AMP is the 60 degree (gg) form, while the major phi rotamer is the 180 degrees (g'g') form. The constrained model, 2',3'-cyclic-CMP, manifests the C3'endo furanose pucker predominantly. The results from these two models are consistent with nuclear magnetic resonance (NMR) J coupling analyses. The phi; distribution of 3'-AMP is dominated (77%) by the 180 degrees g- rotamer. The 3'-AMP results are consistent with phosphorus-hydrogen coupling constant analyses, but do not accord with phosphorus-carbon coupling constant results. The phosphorus-proton NOE reveals that the phosphorus of ApA occupies a region of conformation space not seen in 5'-AMP. The proton-proton NOE on APA shows a significant portion of syn rotamer in both X distributions and detects a cross-purine ring interaction consistent with base stacking known to exist in this system.

Cardiac structure growth pattern determined by echocardiography.

Using M-mode echocardiography, we measured dimensions of the ventricular walls and cavities, great vessels, and left atrium and atrioventricular valve excursions on 93 infants and children without heart disease. The data were analyzed by relating each dimension in mm to body surface area in m2 and the 90% tolerance limits for the data were calculated. The tolerance lines of the data were wider than previously recorded. At birth and maturity they were similar to the range defined as normal by studies in neonates and adults. We suggest that the tolerance lines of these normal data may be used for quantitative echocardiography in childhood.