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Biomedical subjects

D G Ellis

Publications and source records attributed to D G Ellis.

At least 19 recordsLinked to original sources
PubMed1996

Significance of chest trauma in children.

Chest trauma in children is a marker of injury severity and is associated with a high mortality rate. This retrospective study of 1,356 trauma patients from a private pediatric hospital over a 2.5-year period identified 82 patients with chest injuries and a mortality rate of 22%. Results of Injury Severity Score, Glasgow Coma Scale, and Revised Trauma Score all indicated that children with chest injuries sustained more severe injuries. The presence of any extrathoracic injury was associated with a higher mortality (29%) than chest injury alone (4.3%). The type of extrathoracic injury was important, with head and neck injuries resulting in the highest mortality. Specific chest injuries, such as rib fractures and pulmonary contusions, were not related to increased mortality unless there was an associated extrathoracic injury. Many reports have shown a high mortality associated with chest trauma. This study suggests that it is the associated extrathoracic injury, rather than the chest injury itself, that is the real cause of the high mortality.

Abdominal Injuries↗
PubMed1996

The effects of growth factors on Tenon's capsule fibroblasts in serum-free culture.

This study was performed to develop and improve a completely defined in vitro ocular wound-healing model of fibroblast proliferation for glaucoma filtration surgery. This model is essential for the investigation of protein-sensitive drugs and cytokines. Tenon's capsule fibroblasts in their third passage were incubated overnight, washed free of serum, and fed defined media, Aim V or Clonetics FBM serum-free medium containing platelet-derived growth factor, basic fibroblast growth factor, epidermal growth factor, or fibronectin at various dilutions and in combinations at optimum concentrations. Proliferation was measured by 3H-thymidine incorporation at 1, 3, and 7 days. Morphology was compared to controls fed Minimum Essential Medium + 10% serum. Single factors stimulated the greatest amount of thymidine uptake on day 3. Optimum concentrations were epidermal growth factor at 5 ng/ml, basic fibroblast growth factor at 10 ng/ml and platelet-derived growth factor at 20 ng/ml. Identical combinations of factors stimulated nearly twice the thymidine uptake in Clonetics medium as in Aim V. Epidermal growth factor activity was inhibited by either basic fibroblast growth factor or platelet-derived growth factor. Basic fibroblast growth factor and platelet-derived growth factor together produced a less than additive effect. The performance of either serum-free medium may be improved by the addition of basic fibroblast growth factor or platelet-derived growth factor. The optimum serum-free medium (Clonetics FBM) with growth factors was unable to stimulate proliferation as much as Minimum Essential Medium + 10% NBS, but was successful in maintaining viability during the 7 day test period.

Cell Division↗
PubMed1995

A combined hospital experience with fundoplication and gastric emptying procedure for gastroesophageal reflux in children.

BACKGROUND: Operative treatment of symptomatic gastroesophageal reflux (GER), often together with neurologic feeding disorders, is very common in infancy and childhood. Delayed gastric emptying (DGE) has been observed frequently in association with GER in children. STUDY DESIGN: A retrospective review was performed on 1,200 consecutive patients 18 years of age and younger operated upon for symptomatic GER or neurologic feeding disorders, or both, at two pediatric surgery centers in widely separated geographic areas in the United States of America, to compare the results after fundoplication with or without a gastric emptying procedure (GEP). RESULTS: Operations included gastroesophageal fundoplication (GEF) alone (871 patients), GEF plus GEP (286 patients), reoperative GEF plus GEP (30 patients), and GEP alone (13 patients). Thus, 27 percent of the total and 40 percent of the last 494 children with reflux had a GEP. Delayed gastric emptying with retention of more than 60 percent of an isotope meal appropriate for age at 90 minutes was present in 241 of the 451 children with reflux studied. Major neurologic disorders were present in 219 (25 percent) of 871 children who underwent GEF alone and in 247 (75 percent) of 329 children who had a GEP. All patients operated upon from both hospitals were relieved of recurrent emesis, and those with failure to thrive showed significant weight gain; pulmonary symptoms were relieved in 94 percent. Recurrent GER developed in 47 (5.2 percent) of 901 children who had GEF alone, but in only four (1.2 percent) of 329 patients who had a GEP. CONCLUSIONS: The excellent clinical results with low morbidity in this largest reported clinical experience with GEP in childhood suggest that a GEP should be combined with GEF for symptomatic children who have both GER and DGE. Minimal investigative studies are necessary for most neurologically impaired children who require a feeding gastrostomy.

Adolescent↗
PubMed1994

A time to act.

Explore the source record for details and available documents.

Health Care Reform↗
PubMed1991

The effect of tube gastrostomy on gastroesophageal reflux in patients with esophageal atresia.

Gastroesophageal reflux (GER) occurs frequently in infants with esophageal atresia (EA). The definitive management is primary repair and often includes tube gastrostomy. The recent finding of lower esophageal sphincter (LES) pressure changes with tube gastrostomy suggests that GER might be related to gastrostomy rather than EA per se. To evaluate this thesis, two populations of patients from different children's hospitals were reviewed: EA with and without routine gastrostomy. The two populations were similar with respect to number of infants, associated anomalies, distribution in the Waterston classification, morbidity, and mortality. One hundred sixteen patients were studied. Of the 66 survivors who underwent gastrostomy and repair of EA, 30 were found to have GER (45.5%) and 12 required fundoplication (18.2%). Of 31 surviving patients who underwent repair of EA without gastrostomy, 11 had GER (35.5%) and four required fundoplication (12.9%). These data suggest that tube gastrostomy does not significantly contribute to the GER associated with EA.

Esophageal Atresia↗
PubMed1991

Effect of chitosan on lingual hemostasis in rabbits.

Bleeding times were measured for bilateral (15 mm x 2 mm) tongue incisions in 14 New Zealand white rabbits. Using a randomized, blinded experimental design, one incision in each animal was treated with chitosan and the other was treated with control vehicle without chitosan. Extraoral bleeding and coagulation times were also measured for each animal preoperatively, postoperatively, and prior to killing to verify normal bleeding parameters and to evaluate possible systemic effects associated with topical application. Comparison of lingual incisions receiving the experimental substance versus those receiving control solution showed enhanced hemostasis manifested by a 32% (P less than .05) decrease in bleeding time.

Analysis of Variance↗
PubMed1991

Preparation and evaluation of a nonproprietary bilayer skin substitute.

Cross-linked, allogeneic, telopeptide-depleted dermal grafts were lyophilized and laminated with silicone rubber elastomer. Resultant bilayers were studied for incorporation into the wound site and capacity to inhibit cutaneous wound contraction in experimental animals. Bilateral full-thickness skin wounds were made in 20 male New Zealand white rabbits. One side was grafted with the processed graft, while the contralateral side remained ungrafted as a control wound. Over 63 days, wound sites were analyzed at intervals on the basis of the extent and rate of wound contraction and by histologic examination. Cutaneous wounds successfully incorporated graft matrix and were significantly inhibited in their rate and extent of wound contraction. Notably, by day 63, grafted wounds retained 71 percent of their original area, whereas ungrafted control wounds retained only 16 percent of their original area. There were no graft rejections, and the bilayer graft's dermal analogue appeared to function as a biodegradable template that physically conformed neodermis to a preestablished pattern while counteracting contractile forces. This investigation suggests that, in experimental animals, the success of bilayer dermal grafts is less dependent on highly specialized and complex preparative techniques than typically has been presumed and that relatively simple, previously published, nonproprietary techniques, when adapted to a bilayer format, yield acceptable results as defined in terms of biocompatibility, capacity for graft incorporation, and inhibition of wound contraction.

Animals↗
PubMed1989

Chest wall deformities.

Chest wall deformities are principally depression deformities, the most common being pectus excavatum (funnel chest). The most common protrusion deformity is pectus carinatum (pigeon breast). Pectus carinatum is a cosmetic problem, but its presence can be psychologically devastating to the patient. Pectus excavatum is definitely a physiologic problem, the effects of which may be reversible by surgical correction. Surgery is safe, complications are minimal, and results are usually satisfactory.

Funnel Chest↗
PubMed1989

Chest wall deformities in children.

Pectus excavatum and pectus carinatum deformities are not uncommon. Pectus excavatum is associated with definite demonstrable adverse physiologic effects. The psychologic impact of these deformities on the patient can be truly devastating. The clinician must realize the impact and importance of the advice given to patients and their families. Although correction of these deformities is a major surgical undertaking, it is well tolerated, safe, and usually produces a satisfactory result.

Angiocardiography↗
PubMed1988

Healing of cutaneous and mucosal wounds grafted with collagen-glycosaminoglycan/silastic bilayer membranes: a preliminary report.

This report describes the healing of cutaneous wounds in experimental animals grafted with collagen-glycosaminoglycan (GAG) matrix/Silastic (Dow Corning Corp., Midland, MI) bilayers; assesses the feasibility of using collagen-GAG matrix as a vehicle for delivering culture-selected, autogenous fibroblasts to cutaneous wound sites; and evaluates the use of collagen-GAG/Silastic bilayers as mucosal substitutes. Cutaneous and mucosal wounds in New Zealand white rabbits were grafted with either acellular collagen-GAG/Silastic membrane or collagen-GAG/Silastic membrane previously seeded with cultured autogenous fibroblasts. Over 63 days, wound sites were analyzed at intervals based on wound contraction and histology. Cutaneous wound successfully incorporated grafted collagen-GAG matrix and were significantly inhibited in their rate and extent of wound contraction. Seeding membrane matrices with autogenous, cultured fibroblasts before grafting caused a marked increase in cellularity that persisted throughout the postgraft period. In mucosa, matrices were exteriorized rather than incorporated. This work suggests that collagen-GAG/Silastic bilayer may have value as a dermal substitute and, more significantly, may be appropriate as a vehicle for delivering culture-selected fibroblasts to cutaneous wound sites.

Animals↗
PubMed1986

Success rates of blind orotracheal intubation using a transillumination technique with a lighted stylet.

The technique of guided orotracheal intubation using a lighted stylet depends on the transillumination of the soft tissues of the neck to direct the tube through the glottis and into the trachea. We conducted an operating room study of this technique, recording success rates and intubation times of 50 patients undergoing elective surgery. All patients were intubated successfully, 35 of 50 (70%) on the first attempt, 12 of 15 (80%) on the second attempt, and three of three (100%) on the third attempt. The average time for intubation was 37 seconds. A new design of the lighted stylet method resulted from the experience gained. Intubator training and experience influenced initial success rates, and the cadaver laboratory was of particular value in teaching the technique.

Adolescent↗
PubMed1986

Separation and properties of rabbit buccal mucosal wound hyaluronidase.

This study establishes the existence of a mammalian buccal mucosal wound hyaluronidase (hyaluronate 4-glycohydrolase; EC 3.2.1.35) having properties distinct from those of the endogenous lysosomal hyaluronidase of normal (uninjured) buccal mucosa. A time-dependent change in hyaluronidase activity was measured, with the highest specific activity occurring on post-wound day 4 (7.7 +/- 1.3 units/mg protein), followed by consecutive decreases until activity was no longer discernible by day 21. Mucosal wound hyaluronidase closely resembled a previously described integumentary wound endoglycosidase in terms of a high pH optimum (5.0-6.0), distinct (but non-exclusive) substrate preference for hyaluronic acid, and ability to generate saturated depolymerization products by an endoglycosidic hydrolysis.

Animals↗
PubMed1985

Identification and characterization of rabbit buccal mucosal hyaluronidase.

This study establishes the existence of a mammalian buccal mucosal hyaluronidase having properties typical of a lysosomal enzyme. Mucosal hyaluronidase exhibited a distinct substrate preference for hyaluronic acid, generated saturated de-polymerization products by endoglycosidic hydrolysis, and possessed a pH optimum of 3.5 and an isoelectric point of 5.9.

Animals↗
PubMed1983

A computerized mass spectrometer and flowmeter system for respiratory gas measurements.

Instrumentation systems for breath-to-breath analysis of respiratory gas exchange have been faulted by phase lags between various flow and composition signals and by difficulties in gathering and processing large amounts of data. The system described here represents an attempt to overcome these problems. Phase delays have been minimized by using a direct, piezoelectrically operated mass spectrometer inlet rather than an inlet capillary, by locating the mass spectrometer inlet and flow sensors in the same plane, and by incorporating design features which enhance the mass spectrometer response. Convenience in system operation and data analysis has been enhanced by integrating a computer into the system design so that the computer performs on-line data analysis and control functions and provides the primary interface between the experimenter and the instruments. Miniaturization of the instruments permits close coupling to an exercising subject.

Calibration↗
PubMed1981

Voiding abnormalities in children: methods of evaluation and results of treatment.

Recent advances in technology have fueled interest in the field of urodynamics and have made possible accurate diagnosis of voiding abnormalities in children. A thorough understanding of the underlying physiology and institution of the appropriate pharmacologic agents and/or teaching techniques results in correction of the underlying problems in 90% of the cases. Symptoms, techniques of diagnosis, therapeutic regimens, and results of therapy are presented.

Adolescent↗
PubMed1980

Lightweight remotely actuated switching valve for rebreathing exercise studies.

A new type of switching valve used in rebreathing studies for estimating cardiac output is described. This valve employs a unique deformable elastic element, actuated by low-pressure compressed air, to effect switching. The capability for remote operation (via a compressed air line) and the light weight of the valve (110 g) make the valve especially well suited to exercise stress testing studies. Two valves of this type have been satisfactorily used in graded exercise stress tests in a clinical setting for over 2 yr.

Carbon Dioxide↗
PubMed1976

New respiratory gas valve support for graded exercise studies.

We describe a new support structure for respiratory gas valves for use in exercise studies. Use of this structure largely avoids problems of large inertial reactions and feelings of confinement on the part of the subject which have characterized previous systems. The support mechanism consists of a spring-reacted, pivoted boom carried on the end of a counterbalanced swinging beam. This device was designed for use on an adjustable slope motor-driven treadmill, but may be adapted to a variety of other experimental arrangements.

Humans↗