Showing papers by "University of Louisville published in 1987"

Epithelial wound healing enhanced by transforming growth factor-alpha and vaccinia growth factor

Abstract: Epidermal regeneration following middermal injuries to skin requires both proliferation and migration of keratinocytes. Epidermal growth factor (EGF) stimulates the proliferation of keratinocytes in culture, and topical administration of EGF accelerates epidermal regeneration of partial thickness burns or split-thickness incisions in vivo. Transforming growth factor-alpha (TGF-alpha) and vaccinia growth factor (VGF) have substantial sequence homology with EGF, and all appear to bind to the same receptor protein. Whether TGF-alpha or VGF can affect epidermal wound healing in vivo is not known. The present studies show that topical administration of TGF-alpha or VGF in antibiotic cream to partial thickness burns (second degree) accelerated epidermal regeneration in comparison with untreated or vehicle-treated burns. Low levels of both TGF-alpha and VGF (0.1 microgram per milliliter) appeared to be more effective than EGF in stimulating epidermal regeneration. Regenerated epithelium from burns treated with TGF-alpha or VGF appeared normal histologically. This finding suggests that topical application of selected growth factors may be useful in accelerating healing of partial thickness injuries.

Pelvic fracture classification: correlation with hemorrhage.

Abstract: Hemorrhage remains the leading cause of death in patients with pelvic fractures. To identify patients at greatest risk for massive hemorrhage, we retrospectively reviewed charts and initial emergency room anterior-posterior (AP) radiographs of 245 consecutive patients. Pelvic fractures were classified according to our modification of the Pennel and Sutherland classification scheme. A simple pelvic fracture classification scheme was developed. Using this classification, we can be 90% confident that 50 to 69% of patients with "unstable" pelvic fractures will require 4 or more units of blood, 30 to 49% will require greater than 10 units of blood, 36 to 55% will have an intra-abdominal injury, and 6 to 18% will have a pelvic arterial injury. Therefore we conclude that this pelvic fracture classification based on the initial emergency-room AP X-ray can predict a patient population at high risk for massive hemorrhage for which an aggressive treatment protocol is justified.

Stimulation of [3H]dopamine release by nicotine in rat nucleus accumbens.

Abstract: The mesolimbic system of the brain has been shown to be involved in the reward properties of a number of agents. It is possible that release of monoamines by nicotine in this brain area could be related to the pleasurable aspects related to cigarette smoking. In this investigation, the effect of nicotine on the release of [3H]dopamine in the nucleus accumbens of the rat was studied. It was shown that nicotine produced a concentration-dependent increase in [3H]dopamine release at concentrations of 0.1 microM and above. The increase in release was found to be almost completely calcium dependent. The nicotine-induced release was only partially blocked by the nicotinic antagonists hexamethonium and d-tubocurarine. A number of cholinergic agonists, as well as other compounds, were tested for their capacity to mimic the effect of nicotine. At equimolar concentrations there was, at most, only 50% of the activity of nicotine. The results of this study demonstrate that nicotine stimulates the release of dopamine in the nucleus accumbens at concentrations similar to those in the blood of cigarette smokers. This suggests that the release of monoamines in specific nuclei of the mesolimbic system may be an important determinant of the desire to smoke cigarettes.

Microleakage: the effect of storage and cycling duration.

Abstract: This investigation revealed that the limited storage time or cycling durations used had no significant impact on the microleakage patterns of a resin-bonded composite in Class V preparations. Short-term cycling appears as effective in demonstrating marginal leakage as protracted cycling regimens. These findings may be helpful in interpreting and comparing various microleakage studies.

Number of mitral cells and the bulb volume in the aging human olfactory bulb: a quantitative morphological study.

Abstract: The present study documents the morphological changes in the aging human olfactory bulb. Eight bulb pairs from white females between the ages of 25 and 102 years were used. The number of mitral cells in layers IV and III was determined for each bulb and corrected for split cell error. Counts were made on 10-micron thick Nissl-stained sections at 250-micron intervals. The mean number of mitral cells per olfactory bulb at age 25 was estimated from linear regression to be 50,935; at age 60, 32,718; and at age 95, 14,501. The average loss over the time interval studied was 520 mitral cells per year. The volume of each bulb layer, except layer IV, was determined. The difference in the volume of each layer within individuals with age and the total volume with age was not significant (P less than 0.11). The estimated mean bulb volume was found to be 50.02, 43.35, and 36.68 mm3 at ages 25, 60, and 95 years, respectively. The estimated reduction in bulb volume per year increase of age was 0.19 mm3. The ratio of mitral cells to bulb volume for layer III decreased by 19.4 units for every year increase in age. No significant difference was found between the left and the right bulbs in regard to the number of mitral cells and the bulb volume. Histologically, the glomerular layer thickness as well as the mitral cell size and concentration per unit area decreased with age. The intrabulbar anterior olfactory nucleus was discontinuous, highly variable in size, and presumably variable even in neuronal numbers.

Correlation of cerebral perfusion pressure and Glasgow Coma Scale to outcome.

Abstract: Cerebral Perfusion Pressures (CPP) and Glasgow Coma Scale (GCS) scores were monitored to guide the management of severely head-injured patients. These measures were correlated to outcome (Glasgow Outcome Scale-GOS) in 136 consecutive patients at least 1 year after injury. The GOS showed highly significant positive correlations to either CPP or GCS assessments (p less than 0.001). Two parameters that are correlated with subsequent death in most patients include 1) highest (h) GCS = 3 or 4 (Day 1: 31 of 32 patients died, and Day 2: 19 of 19 patients died), and 2) CPP less than or equal to 60 mm Hg more than 33% of the hourly measures during Day 2 (36% of all subsequent deaths; 11% overlap with the highest Glasgow Coma Scale). The Day 2 measures identifying two groups that have a greater than 75% incidence of "good outcome" or GOS = 4 or 5 include 1) hGCS greater than or equal to 6 (N = 45) and 2) the average (a) CPP greater than or equal to 90 mm Hg (N = 26). Of the 45 patients with a GOS = 4 or 5 who had both CPP and GCS recorded on the third day, 44 were identified by these "good outcome" parameters.

Assimilating new technology into the organization: an assessment of McFarlan and McKenney's model

Abstract: Innovation is considered to be an important quality in many successful organizations The nature of the innovation adaptation process within the organization, however, is not well understood This article examines the efficacy of McFarlan and McKenney's diffusion model as a descriptor of actual behavior Specifically, the responses of 412 companies were examined with respect to the integration of personal computers into their organizations The results imply that McFarlan and McKenney's model provides, at least in general, an explanation of technological diffusion

Mozart in the Metropolis: The Arts Coalition and the Urban Growth Machine

Abstract: The performing arts are becoming an important part of the urban growth machine, a development not yet recognized by social scientists. The arts are now a politically acceptable and useful urban growth strategy because of ongoing changes in the nature of cities, in the nature of the economy, and in the nature of the arts themselves, and because of the recent rise of an elite-sponsored political coalition devoted to advancing the strategy. Examples of the use of an arts-centered growth strategy in numerous U.S. cities are presented, and the larger theoretical and practical implications of the phenomenon are explored.

Calcium antagonists preferentially dilate preglomerular vessels of hydronephrotic kidney

Abstract: The hydronephrotic kidney of Inactin-anesthetized female Wistar rats was exteriorized in a controlled bath to directly observe preglomerular and postglomerular vessels via television microscopy. Nitrendipine, added to the bath in a concentration that did not alter blood pressure, induced a concentration-dependent dilation of preglomerular vessels. The arcuate artery maximally dilated by 29 +/- 4%, the interlobular artery by 24 +/- 5%, the afferent arteriole near the interlobular artery by 60 +/- 9%, and near the glomerulus by 28 +/- 13%. In contrast the efferent arteriole near the glomerulus dilated by only 11 +/- 6% and near the welling point by 7 +/- 9%. Similarly, diltiazem significantly dilated preglomerular vessels but not efferent arterioles. Acetylcholine significantly dilated all preglomerular vessels and dilated the afferent arterioles near the glomerulus (by 51 +/- 8%) to a greater extent than the calcium blockers. Acetylcholine also significantly dilated the efferent arterioles (near the glomerulus by 26 +/- 5% and near the welling point by 12 +/- 3%). These data suggest that the tone of the preglomerular vessels of the hydronephrotic kidney is more dependent on the entry of extracellular calcium through calcium antagonist-sensitive channels (i.e., potential dependent) than is the tone of the afferent arterioles near the glomerulus and the efferent arterioles.

Variation in synovial fluid analysis by hospital laboratories.

Abstract: A survey of 42 hospitals revealed that the frequency of synovial fluid analysis was low (mean 3.9 per month). The mean was skewed upward by a higher frequency in 3 teaching hospitals, such that the overall median was 1.5 per month, with 15 hospitals studying 1 or less per month. There did not appear to be any consensus regarding what constitutes a routine synovial fluid analysis. Technical errors occurred, including dilution with acetic acid for cell counts and inappropriate use of automated cell counters. Twenty-six laboratories studied 4 "unknown" fluids for crystals. In 50 opportunities to detect each crystal type, calcium pyrophosphate was detected only 6 times, and sodium urate was detected 39 times. The white blood cell count reported for a single fluid ranged from 2,467-12,000/mm3 (mean +/- SD 6,683 +/- 1,992). The proportion of neutrophils identified varied from 0-30% (mean +/- SD 13.8 +/- 8.6). The majority of respondents believed that training and reference materials related to synovial fluid analysis should be improved.

The Functions of Autolysins in the Growth and Division of Bacillus Subtilis

Abstract: Some bacteria, such as streptococci, exhibit growth from discrete and well-defined zones. In Streptococcus faecalis, growth zones can be observed in the electron microscope, and the position of the zone can be used as a marker for cell cycle events. Growth of the cell surface of Bacillus subtilis appears to be by a much different mechanism from that of streptococci. Cell elongation takes place by the insertion at many sites in the cell cylinder of peptidoglycan components. The insertion occurs on the inner face of the wall, and upon cross linking, the new wall material becomes stress bearing and older wall is pushed to the surface. When old wall reaches the surface, it becomes susceptible to excision by autolysins, resulting in wall turnover; cell elongation, due to the stretching of the cross-linked peptidoglycan, therefore, accompanies turnover and does not require a specialized growth zone.

Venous flaps in digital revascularization and replantation.

Abstract: This is a report on 15 patients who underwent replantation/revascularization of a single digit with a substantial dorsal soft tissue defect. The dorsal defect was covered with a venous flap, a free flap that has only venous inflow and outflow. Postoperatively, the venous flaps were warm, pink, and appeared to exhibit a blanch and refill phenomenon, clinically resembling capillary filling. The flaps from the dorsal aspect of an uninjured digit had a survival rate of 100 percent, with no partial necrosis, while the flaps from a forearm or dorsal foot donor site failed. The advantages of using venous free flaps are twofold. Not only does this technique provide for venous drainage, but it also provides flap coverage and avoids complications, such as vessel occlusion or hematoma formation, associated with skin grafting over a venous anastomosis, with subsequent loss of the skin graft.

Neuroleptic Malignant Syndrome

Abstract: Patient 1: A-16-year-old woman, who lives on a farm and spends time outdoors had been well with no psychiatric history until 1 week prior to admission. At that time, she developed difficulty sleeping and bizarre behavior including assault, sobbing, undressing in public, and thoughts of suicide that prompted admission to the hospital. On examination, she is labile, agitated, and delusional and experiences tactile, visual, and auditory hallucinations. She is found to have impaired recall, dyscalculia, and right-sided sensory deficits. She is started on 2 mg of haloperidol orally twice a day, and she also receives 5 mg intramuscularly for worsening agitation. Within a few hours, she develops a temperature of 39.8°, tachycardia, diaphoresis, and board-like rigidity with cogwheeling, tremors, and mutism. A generalized seizure is observed. Despite administration of diphenylhydantoin, steroids, diazepam, benztropine, and three electroconvulsive treatments, she remains rigid and unresponsive with temperatures up to 40.5°.

A layout design heuristic employing the theory of fuzzy sets

Abstract: This paper discusses various techniques for layout planning and outlines an application of fuzzy set techniques to the block layout design problem. In particular, a fuzzy linguistic heuristic for the location of the departments within a facility is proposed. This heuristic utilizes imprecise descriptors for two distinct design categories: closeness and importance, expressed in the form of fuzzy relations for every pair of departments. A numerical example is given to illustrate the proposed approach and directions for further research are discussed.

Death from uveal melanoma: number of epithelioid cells and inverse SD of nucleolar area as prognostic factors

Abstract: • Criteria for the Callender classification of uveal melanoma are subjective and lead to variations among observers of the same tumor. Two other measures for cell type—the number of epithelioid cells per high-power field (Epi/HPF) and the inverse SD of nucleolar area (ISDNA)—were evaluated as prognostic factors for survival following enucleation for uveal melanoma in 232 patients. Variables significantly related to the number of Epi/ HPF were related to ISDNA. Larger, more anteriorly located tumors had a high number of Epi/HPF and a low ISDNA. The two measures were also correlated. Using Kaplan-Meier survival analysis, both measures were related to tumor deaths. Worse prognosis was associated with a higher number of Epi/HPF and a lower ISDNA. Considered together in Cox' proportional hazards analysis, both measures independently predicted outcome. Separately, each measure predicted uveal melanoma-related deaths, in combination with largest tumor dimension, invasion of tumor to the line of transection, and location of the anterior tumor margin. Although ISDNA is the more objective measure of cell type, its practicality compared with other measures of cell type must also be considered.

Death From Uveal Melanoma: Number of Epithelioid Cells and Inverse SD of Nucleolar Area as Prognostic Factors

Abstract: • Criteria for the Callender classification of uveal melanoma are subjective and lead to variations among observers of the same tumor. Two other measures for cell type—the number of epithelioid cells per high-power field (Epi/HPF) and the inverse SD of nucleolar area (ISDNA)—were evaluated as prognostic factors for survival following enucleation for uveal melanoma in 232 patients. Variables significantly related to the number of Epi/ HPF were related to ISDNA. Larger, more anteriorly located tumors had a high number of Epi/HPF and a low ISDNA. The two measures were also correlated. Using Kaplan-Meier survival analysis, both measures were related to tumor deaths. Worse prognosis was associated with a higher number of Epi/HPF and a lower ISDNA. Considered together in Cox' proportional hazards analysis, both measures independently predicted outcome. Separately, each measure predicted uveal melanoma-related deaths, in combination with largest tumor dimension, invasion of tumor to the line of transection, and location of the anterior tumor margin. Although ISDNA is the more objective measure of cell type, its practicality compared with other measures of cell type must also be considered.

Specificity of the fucose-binding lectin of Pseudomonas aeruginosa

Abstract: PA-II lectin of Pseudomonas aeruginosa , purified by affinity chromatography, was examined for its relative affinity to various carbohydrates using equilibrium dialysis and hemagglutination inhibition tests. This lectin was found to exhibit a high affinity for l-fucose and its derivatives. Among them, p-nitrophentl-α-l-fucose was the strongest inhibitor, followed by l-fucose →l-fucosylamine l-galactose →d-mannose →?→d-fructose. The association constant ( K a) of l-focuse for PA-II was 1.5 × 106· M−1 and the number of the l-fucose-binding sites per protein subunit was approximately 1. The K a of d-mannose for PA-II was 3.1 × 10−2· M−1 and a value of 0.84 was obtained as the number of its binding sites per mole protein subunit.

Growth Factors and Corneal Epithelium

Abstract: Regeneration of corneal epithelium following injury is essential for visual rehabilitation. A limited number of approaches are available for treating patients who fail to heal epithelial injuries adequately. The presence of specific receptors for epidermal growth factor (EGF) on epithelial cells suggests that this potent mitogen may play a role in normal epithelial wound healing. Topical application of biosynthetic human EGF significantly accelerated epithelial regeneration in primates following epikeratophakia surgery. Epidermal growth factor alone and with fibronectin accelerated epithelial regeneration of rabbits following mild alkali burns. Since prolonged exposure of cells to EGF is necessary to induce mitosis, the dynamics of EGF in the eye and with various lenses was studied. When applied in methylcellulose-based eye drops, 90% of the EGF was lost from tear film within 10 min, while a small amount (10%) remained associated with conjuctival tissue. Soft contact lenses or epikeratophakia lenticles took up substantial amounts of EGF (50 micrograms) and released 85% of the EGF within 24 h, with a half-life of 4 h in vitro. Epidermal growth factor did not diffuse through corneas or lenticles and did not promote epithelial downgrowth along sutures in primate corneas. These results suggest that biosynthetic growth factors may be useful in the treatment of some epithelial injuries.