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Biomedical subjects

D Bowling

Publications and source records attributed to D Bowling.

9 recordsLinked to original sources

Autologous, cadaveric, and synthetic materials used in sling surgery: comparative biomechanical analysis.

OBJECTIVES: To compare the biomechanical properties of allografts, autografts, and synthetic materials used in sling surgery using the Instron tensinometer. METHODS: The sling grafts we studied consisted of autologous tissues (dermis, rectus fascia, and vaginal mucosa), cadaver tissues (decellularized dermis and freeze-dried, gamma-irradiated fascia lata), and synthetics (Gore-Tex and polypropylene mesh). The sling grafts were constructed into two types of slings: full strip sling (FSS) versus patch suture sling (PSS). The slings were loaded onto the Instron tensinometer and uniaxially loaded in tension until failure. From the load deformation curve, the mechanical properties of the sling grafts were compared. RESULTS: A total of 140 sling grafts were analyzed. In rank order for the FSSs, cadaver allografts had the strongest tensile strength followed by the synthetics and autologous tissues (P <0.05). The tensile strength of the FSSs was greater than for the PSSs for all groups (P </=0.001). In rank order for the PSSs, the synthetics and dermal tissues (autograft and allograft) had the highest tensile strength followed by cadaver fascia lata, rectus fascia, and vaginal mucosa (P <0.05). CONCLUSIONS: The tensile strength of the FSS was greater than that of the PSS for the autograft, allograft, and synthetic tissues. The autograft and allograft tissues were significantly weaker as a PSS. The synthetics were more durable as a PSS compared with the organic tissues. When a PSS is constructed from autograft and allograft tissues, the risk of suture pull-through and recurrent stress incontinence must be considered.

Biomechanical Phenomena↗

Enteral glutamine supplementation for very low birth weight infants decreases morbidity.

Glutamine, described as a "conditionally essential" amino acid for critically ill patients, has not been routinely added to parenteral amino acid formulations for critically ill neonates and is provided in only small quantities by the enteral route when enteral intake is low. We conducted a blinded, randomized study of enteral glutamine supplementation in 68 very low birth weight neonates randomly assigned to receive glutamine-supplemented premature formula versus premature formula alone between days 3 and 30 of life. Primary end points consisted of hospital-acquired sepsis, tolerance to subsequent enteral feedings (days with no oral intake), and duration of hospital stay. Hospital acquired sepsis was 30% (control group) and 11% (glutamine group). Logistic regression with birth weight as a covariate showed that: (1) feeding group was significant (p = 0.048) in determining the probability of developing proven sepsis over the course of hospitalization and (2) the estimated odds of developing sepsis were 3.8 times higher for infants in the control group than for those treated with glutamine. Glutamine-supplemented infants had better tolerance to enteral feedings as measured by percent of days on which feedings needed to be withheld (mean percentage of 8.8 vs 23.8, p = 0.007). Analysis of T cells demonstrated a blunting of the rise in HLA-DR+ and CD16 subsets in glutamine-supplemented infants. There were no differences in growth; in serum ammonia, urea, liver transaminase, or prealbumin concentrations; or in mean hospital stay. This study provides evidence for decreased morbidity in very-low-birth-weight neonates who receive enteral glutamine supplementation.

Diet Therapy↗

Spatial memory deficits in aged rats: contributions of monoaminergic systems.

Age-dependent changes in monoaminergic systems and their relationship to senescent memory decline were investigated in 4- and 25-26-month-old, female, Fischer 344 rats. Spatial memory performance was tested on an 8-arm radial maze, and levels of norepinephrine (NE), dopamine (DA) and metabolites 3,4-dihydroxyphenylacetic acid and homovanillic acid, serotonin (5-HT) and metabolite 5-hydroxyindoleacetic acid were measured in brain areas which contribute to memory function--basal forebrain cholinergic nuclei, subfields of the hippocampus, frontal and entorhinal cortex--and in monoaminergic cell body areas. The performance of aged subjects was significantly impaired as compared to young subjects, and alterations of 20-60% in monoamine and metabolite levels were measured in specific brain areas of aged rats. Decreased NE levels were found in basal forebrain nuclei and cortical areas but not in hippocampal subfields of aged rats. Changes in the 5-HT system were present in hippocampal, cortical and basal forebrain sites. Changes in the DA system were the most pervasive with aged rats showing decreased DA and/or metabolites in several basal forebrain nuclei, cortical areas, and the hippocampus. Aged rats showed 50% decreases of monoamines in locus coeruleus and substantia nigra and 30% decreases in the dorsal raphe nucleus. Some but not all of the changes correlated with memory performance. The present results in rats support evidence that age-dependent changes in monoaminergic function in discrete brain sites contribute to senescent memory decline and suggest that monoaminergic-cholinergic interactions within basal forebrain nuclei may be important in this decline.

Aging↗

Computed tomography and the thyroglossal duct cyst.

Thyroglossal duct cysts (TDC) classically present as midline neck masses in close relation to the hyoid bone; yet--not uncommonly--their locations may be varied from the midline and from the hyoid. By means of the diagnostic modality of computed tomography (CT), high-resolution images of several cases of alternate presentations and locations of the TDC are examined. Included are examples of TDC in the suprahyoid, transhyoid, infrahyoid, and lateral positions. The potential value of CT in the diagnosis of the unusual cyst will be demonstrated and discussed.

Adult↗

Destruction of a single cell in the central nervous system of the leech as a means of analysing its connexions and functional role.

A method has been devised for killing an individual neurone in the C.N.S. of the leech by injecting it with Pronase. The technique has been used to examine the role of individual sensory and motor cells involved in producing reflex movements.1. After a neurone was injected with Pronase, either in an intact animal or an isolated ganglion, its cell body lost its resting and action potentials. Some hours later the injected cell's axons in the periphery failed to conduct impulses. In the intact animal the cell body could no longer be discerned after a few weeks.2. To test for destruction of processes within the neuropile, cells were injected first with the enzyme horseradish peroxidase (HRP) and then several hours later with Pronase. Absence of the characteristic HRP reaction product indicated that Pronase had spread throughout the arborization of the cell.3. Injection of Pronase into one cell did not produce overt electrophysiological or anatomical changes in other cells in the ganglion including neurones that were originally electrically coupled to the killed cell.4. Evidence that an individual cell was the only motoneurone supplying particular muscles was provided by destruction of that cell in otherwise intact animals, which resulted in a characteristic motor deficit in the area supplied by the killed cell. Over a period of months, functional recovery of the affected muscles occurred by way of homologous cells in adjacent ganglia.5. A further application of the technique was to trace the connexion that a particular sensory neurone makes onto two motoneurones that are electrically coupled. Normally, the sensory neurone gives rise to excitatory potentials in both post-synaptic cells. Synaptic potentials could still be recorded in one motor cell after the other had been destroyed by Pronase, indicating that synapses were made directly onto both of the motoneurones.

Animals↗

Meconium passage in very-low-birth-weight infants.

The timing of the first meconium stool has been considered a marker for proper gastrointestinal functioning in the term infant. There is limited information on the meconium passage patterns of very-low-birth-weight infants of less than 32 weeks' gestation. It is unknown whether feeding practices influence the timing of the first stool in these infants. We retrospectively studied 47 very-low-birth-weight infants with birth weights of 1250 g or less who were previously enrolled in a study of gastrointestinal (GI) priming. Infants whose mothers desired to breast feed (n = 7) were given GI priming with their own mother's milk. The remaining infants had been randomly assigned to receive total parenteral nutrition alone (n = 21) or GI priming with infant formula (n = 19) during the first 14 days of life. We attempted to advance all infants to full enteral nutrition by 21 days of age. There was no statistically significant difference in timing of the first stool among the three groups. The overall median age at first stool was 43 hours, and the 75th percentile was 10 days. The range was 1/2 hour to 27 days. There was no concordance between time of first stool and birth weight within the range studied. There was no concordance between time of first stool and necrotizing enterocolitis, although there was little statistical power to detect this. There was also very little concordance with feeding tolerance. Other than necrotizing enterocolitis, no significant GI disease developed in any of the infants studied.(ABSTRACT TRUNCATED AT 250 WORDS)

Birth Weight↗

Enteral glutamine supplementation for very-low-birth-weight infants decreases hospital costs.

BACKGROUND: There is growing evidence that glutamine may be a conditionally essential amino acid for critically ill patients, including preterm infants cared for in neonatal intensive care units (NICUs). In a randomized study of 68 very-low-birth-weight (VLBW) infants, we found evidence of lower morbidity in a group fed glutamine-supplemented preterm infant formula from postnatal day 3 to day 30 than in a group fed a standard formula. We report here the effects of the glutamine supplementation on hospital costs in these infants. METHODS: The costs were analyzed by log-rank tests and Kaplan-Meier plots. RESULTS: The median costs for hospitalization, radiology, pharmacy, laboratory, and the NICU, and the median number of utilization units were reduced with glutamine supplementation. CONCLUSIONS: This study provides the first evidence for decreased hospital costs in VLBW neonates who receive enteral glutamine supplementation.

Birth Weight↗