Inguinal hernia repair in infants less than six months of age.

Previous studies reviewing the morbidity and mortality of infant inguinal hernia surgery have all been done in university hospital settings. From our community-based tertiary hospital, 100 consecutive cases on infants less than six months of age, undergoing inguinal hernia repair, were reviewed. No infants were excluded. Sixty-eight were full term and 32 were premature. A number of different variables were analyzed and none appeared to affect outcome. Infants were followed for three to five years. There were no true complications in any infant in this series, although six infants developed wound erythema that resolved spontaneously. Parents were given a questionnaire to subjectively evaluate the infant before and after surgery with 78% showing improvement.     

Spectral characteristics of speech at the ear: implications for amplification in children.

This study examined the long- and short-term spectral characteristics of speech simultaneously recorded at the ear and at a reference microphone position (30 cm at 0 degrees azimuth). Twenty adults and 26 children (2-4 years of age) with normal hearing were asked to produce 9 short sentences in a quiet environment. Long-term average speech spectra (LTASS) were calculated for the concatenated sentences, and short-term spectra were calculated for selected phonemes within the sentences (/m/, /n/, /s/, [see text], /f/, /a/, /u/, and /i/). Relative to the reference microphone position, the LTASS at the ear showed higher amplitudes for frequencies below 1 kHz and lower amplitudes for frequencies above 2 kHz for both groups. At both microphone positions, the short-term spectra of the children's phonemes revealed reduced amplitudes for /s/ and [see text] and for vowel energy above 2 kHz relative to the adults' phonemes. The results of this study suggest that, for listeners with hearing loss (a) the talker's own voice through a hearing instrument would contain lower overall energy at frequencies above 2 kHz relative to speech originating in front of the talker, (b) a child's own speech would contain even lower energy above 2 kHz because of adult-child differences in overall amplitude, and (c) frequency regions important to normal speech development (e.g., high-frequency energy in the phonemes /s/ and [see text]) may not be amplified sufficiently by many hearing instruments.     

Effect of aging on wound healing: current concepts.

The population is aging, and advanced age is commonly identified as a risk factor for delayed wound healing. Therefore, it is important for WOC nurses to be knowledgeable about how aging affects the wound healing and repair process, and strategies they can use to promote healing in the elderly population. Impaired wound healing in the aged is due partly to comorbidities common among the elderly, but evidence also suggests that inherent differences in cellular structure and function may impair tissue repair and regeneration as well. This article will address the effect of aging on wound healing, with a particular focus on processes of cellular senescence and related factors hypothesized to result in slowed or impaired wound healing in the elderly.     

Localization of tissue plasminogen activator mRNA in adult rat brain

The distribution of tissue plasminogen activator (tPA) messenger RNA in rat brain was studied using in situ hybridization with ³⁵S UTP-labeled RNA probes derived from a fulllength tPA cDNA. Sense strand controls produced low, even backgrounds, with small elevations in the hippocampus. Full-length antisense probes produced strong signals over cerebral ventricular ependyma (including ependyma of the subcommissural organ), meninges, blood vessels, and Purkinje cell layer of the cerebellum, as well as strong signals over scattered cells throughout the brain. Some of these scattered labeled cells were large with lightly stained nuclei, while others were small with darkly stained nuclei. The large labeled cells, which were probably neurons, constituted 8% and 8% of cells in the brain stem and neocortex, respectively, and 100% of Purkinje cells. The small cells, which were present in all areas of the brain, constituted 3–11 % of cells in individual brain areas.     

Determination of Red Blood Cell Velocity by Video Shuttering and Image Analysis

A novel modification of conventional video imaging techniques has been developed to determine the velocity of red blood cells (RBCs), which offers compatibility with existing video-based methods for determining blood oxygenation and hemoglobin concentration. Traditional frame-by-frame analysis of video recordings limits the maximum velocity that can be measured for individual cells in vivo to about 2 mm/s. We have extended this range to about 20 mm/s, by electronic shuttering of an intensified charge-coupled device camera to produce multiple images of a single RBC in the same video frame. RBCs were labeled with fluorescein isothiocyanate and the labeled cells (FRBCs) were used as probes to determine RBC velocities in microvessels of the hamster retractor muscle. Velocity was computed as the product of the distance between centroids of two consecutive image positions of a FRBC and the shuttering frequency of the camera intensifier. In vitro calibrations of the system using FRBC and Sephadex beads coated onto a rotating disk yielded an average coefficient of variation of about 6%. Flow conservation studies at bifurcations indicated that the maximum diameter of microvessels below which all the FRBCs in the lumen could be detected was 50 m. The technique was used to estimate mean-FRBC velocity distributions in vessels with diameters ranging from 8 to 50 m. The mean-FRBC velocity profiles were found to be blunter than would be expected for Poiseuille flow. Single FRBCs tracked along an unbranched arteriole exhibited significant temporal variations in velocity. © 1999 Biomedical Engineering Society. PAC99: 8719Tt, 8717Jj, 4279Pw, 8780Tq, 8719Ff, 4230Va, 0705Pj     

Androgen receptor YAC transgenic mice carrying CAG 45 alleles show trinucleotide repeat instability

X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG repeat expansion in the first exon of the androgen receptor (AR) gene. Disease-associated alleles (37-66 CAGs) change in length when transmitted from parents to offspring, with a significantly greater tendency to shift size when inherited paternally. As transgenic mice carrying human AR cDNAs with 45 and 66 CAG repeats do not display repeat instability, we attempted to model trinucleotide repeat instability by generating transgenic mice with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions in their genomic context. Studies of independent lines of AR YAC transgenic mice with CAG 45 alleles reveal intergenerational instability at an overall rate of approximately 10%. We also find that the 45 CAG repeat tracts are significantly more unstable with maternal transmission and as the transmitting mother ages. Of all the CAG/CTG repeat transgenic mice produced to date the AR YAC CAG 45 mice are unstable with the smallest trinucleotide repeat mutations, suggesting that the length threshold for repeat instability in the mouse may be lowered by including the appropriate flanking human DNA sequences. By sequence-tagged site content analysis and long range mapping we determined that one unstable transgenic line has integrated an approximately 70 kb segment of the AR locus due to fragmentation of the AR YAC. Identification of the cis - acting elements that permit CAG tract instability and the trans -acting factors that modulate repeat instability in the AR YAC CAG 45 mice may provide insights into the molecular basis of trinucleotide repeat instability in humans.      

Stimulation of chronic lymphatic leukaemia cells by pokeweed mitogen after treatment with neuraminidase-galactose oxidase.

CLL lymphocytes gave a low response upon stimulation with PHA or PWM in 3-day cultures. However, after treatment with neuraminidase-galactose oxidase (NGO), in the presence of PWM, CLL lymphocytes transformed into blasts and incorporated 3H-thymidine in 3-day cultures. This response of CLL lymphocytes was similar to that given by normal lymphocytes to PWM in 3-day cultures. The best stimulation of CLL lymphocytes was achieved when conditioned medium (CM) from normal T lymphocytes was present in PWM cultures. Purified B lymphocytes from CLL (T lymphocytes and monocytes removed) did not respond to PHA or PWM. However, after NGO treatment these cells were stimulated by PWM, but only in the presence of CM. PHA failed to stimulate NGO-treated CLL lymphocytes or purified B lymphocytes. This study shows that CLL lymphocytes, which usually fail to respond to mitogens, can be stimulated by PWM to proliferate after treatment with neuraminidase-galactose oxidase (NGO). This technique of B cell stimulation has been found useful in cytogenetic studies of B cell proliferative disorders.