Extraction of RNA from single frozen sections

PURPOSE: Recently, mutations in several genes have been identified as being responsible for the pathogenesis of autosomal recessive retinitis pigmentosa (arRP). These genes include rhodopsin, beta-subunit of rod cGMP phosphodiesterase (PDEB), alpha-subunit of rod cGMP phosphodiesterase (PDEA), and alpha-subunit of rod cGMP-gated channel. We here attempted to identify a novel mutation in the PDEB gene in Japanese arRP patients. METHODS: Using the PCR-SSCP method, sequencing analysis, and restriction endonuclease digestion assay, we analyzed the PDEB gene in 17 Japanese families with non-dominant retinitis pigmentosa. RESULTS: A novel Ile535Asn mutation was identified in two patients in a single family and the mutation cosegregated with RP in this family. Among 90 unrelated healthy individuals, no one was identified as homozygous for this mutation, except for one individual who was found to be heterozygous. CONCLUSIONS: Isoleucine at codon 535 in the PDEB gene is conserved among various mammals. Missense mutations of the PDEB gene causing arRP have been reported in a limited region (codon 527-codon 699) in which codon 535 is located. Thus, the Ile535Asn mutation is an additional missense mutation which is responsible for the pathogenesis of arRP.     

Fast variance calculation of polyreference least-squares frequency-domain estimates

One major drawback of the PolyMAX estimator, a polyreference least-squares frequency-domain estimator, is the lack of confidence bounds on the estimated modal parameters. This paper proposes a fast two-step approach to determine the variances on the estimated polynomial parameters and next on the resonance frequencies and damping ratios. The approach is based on the linearization of the sensitivity of the modal parameters to the noise variance. This noise variance (explicitly or as the coherence function) is assumed to be known a priori. The approach is tested on simulations and real-life measurements.     

Modulation of antioxidant enzymes and programmed cell death by n-3 fatty acids

Studies from our laboratory indicate that n-3 (fish oil, FO) lipids at 10% (w/w) in a nutritionally adequate, semipurified diet, and supplemented with equal levels of antioxidants, extended the life span of lupus-prone (NZB/NZW)F₁ (B/W) female mice as compared to n-6 (corn oil, CO) lipids. The early rise of autoimmune disease in CO-fed mice was closely linked to the loss of T-cell function. Both IL-2 production and IL-2 receptor expression were reduced due to the loss of naive T-Cells and a rise in memory T-cells. Proliferative response to both mitogens and superatigens (staphylococcal enterotoxins A and B) was higher in FO-fed 6.5-mon-old mice. These changes paralleled decreased PGE₂ production by splenic cells from FO-fed mice. Analysis of mRNA expression in different organs revealed differential effects of dietary lipids. In FO-fed, mice, transforming growth factor β1 (TGF β1) expression was decreased in kidneys, but splenic tissues had higher expression of TGF β mRNA. As TGF β promotes programmed cell death (PCD), we studied the effects of CO and FO on PCD rates in lymphocytes. Both propidium iodide staining and DNA fragmentation were elevated in lymphocytes of FO-fed mice when compared to CO-fed mice of similar age. Also, increased PCD correlated closely with increased Fas gene expression. Thus, in addition to various other antiinflammatory effects, dietary FO appears to increase PCD and prevent accumulation of self-reactive immune cells in lymphoid organs. Further studies are required to dissect the proand antiinflammatory mechanisms associated with dietary n-3 and n-6 lipids in modulating autoimmune disorders or malignancy during aging.     

Mechanical advantage of sternomastoid and scalene muscles in dogs

Theoretical studies have led to the prediction that the maximal effect of a given respiratory muscle on airway opening pressure (Pao) is the product of muscle mass, the maximal active muscle tension per unit cross-sectional area, and the fractional change in muscle length per unit volume increase of the relaxed chest wall. It has previously been shown that the parasternal intercostals behave in agreement with this prediction (A. De Troyer, A. Legrand, and T. A. Wilson. J. Physiol. (Lond) 495: 239-246, 1996; A. Legrand, T. A. Wilson, and A. De Troyer. J. Appl. Physiol. 80: 2097-2101, 1996). In the present study, we have tested the prediction further by measuring the response to passive inflation and the pressure-generating ability of the sternomastoid and scalene muscles in eight anesthetized dogs. With 1-liter passive inflation, the sternomastoids and scalenes shortened by 2.03 +/- 0.17 and 5.98 +/- 0.43%, respectively, of their relaxation length (P < 0.001). During maximal stimulation, the two muscles caused similar falls in Pao. However, the sternomastoids had greater mass such that the change in Pao (delta Pao) per unit muscle mass was -0.19 +/- 0.02 cmH2O/g for the scalenes and only -0.07 +/- 0.01 cmH2O/g for the sternomastoids (P < 0.001). After extension of the neck, there was a reduction in both the muscle shortening during passive inflation and the fall in Pao during stimulation. The delta Pao per unit muscle mass was thus closely related to the change in length; the slope of the relationship was 3.1. These observations further support the concept that the fractional changes in length of the respiratory muscles during passive inflation can be used to predict their pressure-generating ability.     

Clustering and switching as two components of verbal fluency: Evidence from younger and older healthy adults.

Although verbal fluency is a frequently used neuropsychological test, little is known about the underlying cognitive processes. The authors proposed that 2 important components of fluency performance are clustering (i.e., the production of words within semantic or phonemic subcategories) and switching (i.e., the ability to shift between clusters). In Experiment 1, correlational data from 54 older and 41 younger adults indicated that both components were highly correlated with the number of words generated on semantic fluency, whereas switching was more highly correlated than clustering with the number of words generated on phonemic fluency. On semantic fluency, younger participants generated more words and switched more frequently than older participants; on phonemic fluency, older participants produced larger clusters than younger participants. In Experiment 2, among 22 young adults, divided attention decreased the number of words generated and decreased switching on phonemic fluency only. Overall, findings suggest that clustering and switching are dissociable fluency components and that switching is related to frontal-lobe functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fast calculation of confidence intervals on parameter estimates of least-squares frequency-domain estimators

The least-squares complex frequency-domain (LSCF) estimator—commercially known as the PolyMAX estimator—nowadays is used intensively in various modal analysis applications. The main advantages are the very clear stabilization diagrams and even more important, the speed. In this paper it is shown that confidence intervals of the modal parameter estimates can be derived without major additional calculations, if the frequency response functions are uncorrelated and noise information (e.g. the coherence function) is available. This approach is also applied to the iterative quadratic maximum likelihood (IQML) estimator, indicating strong analogies to the maximum likelihood (ML) estimator. The algorithm is evaluated by means of Monte Carlo simulations.     

Respiration mechanics in tetraplegia

Patients with quadriplegia due to transection of the lower cervical cord show, on spirographic examination, a marked decrease in vital capacity and its two components, i.e. inspiratory capacity (i.c.) and expiratory reserve volume (ERV). The loss of IC results partly from the decreased inspiratory muscle strength consecutive to the intercostal muscle paralysis but mostly from a reduction in the distensibility of the lungs and the rib cage. The reduction in ERV is related to the paralysis of all the well-recognized muscles of expiration (abdominals, interosseous internal intercostals); however, the clavicular portion of the pectoralis major allows these patients to maintain a small ERV.     

Rectovaginal constriction in Jersey cattle: genetics and breed dynamics

Data from farmer-owned herds and from experimental matings supported monofactorial recessive inheritance of rectovaginal constriction in US Jersey cattle. Kempthorne's population genetics model of a recessive trait involving only male selection was extended to include mutation and converted to selection of females only. Computer analyses with that model estimate slow decline in the frequency of the gene for rectovaginal constriction. Practical dynamics of the disorder in a breed registering 50,000 females and 2,000 males annually are given for current conditions and after 500 generations of selection.     

A simple film speed regulator for microcinematography

A regulator is described which holds the film speed of a very economical 16 mm camera constant at filming speeds of 5–35 frames/s.