Showing papers by "University of Louisville published in 1977"

Primary flexor tendon repair followed by immediate controlled mobilization

Abstract: A study was made of the results of immediate repair and controlled mobilization in 156 severed flexor tendons in 68 patients occuring over an 18-month period. Eight patients with 16 tendon injuries could not be followed. Results were obtained from examinations done 6 weeks to 18 months (mean, 5.3 months) after repair. Thirty-one of the 60 patients were less than 20 years old, and 44 of the 60 were less than 30 years old. Seventy-nine (56%) of the injuries occurred in the area known as "no man's land"; 28 patients with repair of tendons in this area were rated by our standards as "excellent" or "good"--75% of patients as compared to 84.4% for the results of repair in other areas. In one fourth of the cases of severance of both tendons, because of local conditions in the wound, the superficialis was excised, but in all others it was repaired.

The Microbiology of Aquatic Oil Spills

Abstract: Publisher Summary This chapter discusses the microbiology of aquatic oil spills. Immediately upon spilling, oil begins to undergo a series of physical and chemical changes. The processes causing these changes include spreading, emulsification, dissolution, evaporation, sedimentation, and adsorption. Collectively, the oil is weathered by these processes. The weathering of oil depends on the amount and type of oil spilled, and on environmental conditions. Petroleum hydrocarbons have only a very limited solubility in water. Therefore, most oil spillages initially form a surface slick. The surface slick can be moved by wind, wave, and current action. A surface oil slick immediately begins to spread, initially owing to gravitational forces, resulting in a thinner layer of oil covering a larger area. The viscosity of the spilled oil will, to some extent, influence the rate of spreading and, as viscosity is temperature dependent, water temperature will also influence the area covered by a surface slick. The chapter illustrates the effects of petroleum hydrocarbons on microorganisms, microbial emulsification and degradation of petroleum, and the microorganisms and oil pollution abatement.

The American Society for Surgery of the Hand

Abstract: These questions, often asked during my year as President, inspired the following address. 1. What is the recommended time for hand surgery training? 2. What should this training include? 3. If hand surgery is established as a specialty, does this exclude the general, orthopaedic, or plastic surgeon not trained specifically in this type of surgery? 4. How many hand surgeons does this country need? 5. What hand surgical services should be provided by a community hospital? By a medical center hospital? 6. What would be the effect of national health insurance? The three major components of an effective, innovative medical program are (1) direct patient care, (2) teaching, and (3) research (Fig. 1). These may be envisioned as three overlapping circles, as in a Venn diagram. Direct patient care is the first priority, and when effectively administered, strong teaching and research capabilities follow (Fig. 2). Teaching stimulates research, for it is from the interchange between teacher and student that new ideas are created (Fig. 3). From the resolution of these ideas, new knowledge and service emerge (Fig. 4). Patient care is either elective or emergency. The statement, "The surgeon who first operates plays the greatest role in the eventual outcome and the final result achiev.ed, " especially applies to the emergency patient. The productive time lost by our nation from hand injuries sustained at work and home is so large that its value has not been estimated accurately. Patients are usually off of work or regular activity for 3 to 6 weeks following even minor hand injuries. If one combines

Replantation of digits and hands: Analysis of surgical techniques and functional results in 71 patients with 86 replantations

Abstract: Defining replantation as the restoration of a completely amputated part as opposed to simply restoring circulation to an incompletely severed part, the results of replantation of 86 completely amputated parts in 71 patients performed from January, 1970, to December, 1975, were studied. Twenty-eight, or 32.5 percent, were the result of sharp severances of the part; localized crushing accounted for 56, or 65.1 percent. Two were classified as degloving injuries. Twelve amputations were transmetacarpal, six were at the metacarpophalangeal joints, 14 through the proximal phalanx, 15 at the proximal interphalangeal joint, 21 in the middle phalanx, 13 at the distal interphalangeal joint, and five through the distal phalanx. The technique consisted of bone shortening and fixation and repair of all tendons and nerves if possible. Veins are repaired first, at least two for each artery, and heparinized saline and lidocaine are used locally. Irrigation of the vessels is not done, but an intravenous bolus of 3,000 U. of heparin is given when the anastomoses are completed. Aspirin and low molecular weight dextran are given for 3 to 7 days. For the more distal replantation, heparin may be used. Antibiotics are given. In the total series of 86 completely amputated hand units, 52 were unsuccessful, primarly due to vascular thrombosis and usually on the venous side. In the year 1975 a success rate of 69.2 percent was achieved, whereas in the last 50 replantations, done between Jan. 1, 1976, and Oct. 15, 1976, the success rate was 90 percent. Results improved with more experience in the technique and with more careful selection of patients.

Stimulated petroleum biodegradation.

Abstract: Stimulated biodegradation has been considered as a method for removal of petroleum pollutants. Various methods have been proposed for increasing rates of petroleum biodegradation, including physical or chemical modification of petroleum polutants, modification of environmental parameters around polluting oil, and modification of microbial populations around petroleum pollutants. Physical or chemical means for stimulating petroleum biodegradation include removal of particular petroleum fractions by dissolution, burning, and emulsification. Modification of environmental parameters (such as concentrations of essential nutrients, especially nitrogen, phosphorus, and oxygen) has shown the greatest promise for stimulating petroleum biodegradation. Forced aeration and addition of commercial fertilizer combinations in contained systems, addition of fertilizer with tilling in soil, and addition of fertilizer that has been rendered oleophilic in open systems have all been shown to effectively stimulate petroleum biodegradation. Modification of microbial populations by seeding with oil-degrading microorganisms appears to be valuable in stimulating petroleum biodegradation only in limited situations where the naturally occuring numbers of hydrocarbon-degrading microorganisms are low.

Journal bearing impedance descriptions for rotordynamic applications

Abstract: Bearing impedance vectors are introduced for plain journal bearings which define the bearing reaction force components as a function of the bearing motion. Impedance descriptions are developed directly for the approximate Ocvirk (short) and Sommerfeld (long) bearing solutions. The impedance vector magnitude and the mobility vector magnitude of Booker are shown to be reciprocals. The transformation relationships between mobilities and impedance are derived and used to define impedance vectors for a number of existing mobility vectors including the finite-length mobility vectors developed by Moes. The attractiveness and utility of the impedance-vector formulation for transient simulation work is demonstrated by numerical examples for the Ocvirk "p", and "2p" bearing impedances and the cavitating finite-length-bearing impedance. The examples presented demonstrate both bearing and squeeze-film damper application. A direct analytic method for deriving a complete set of (analytic) stiffness and damping coefficients from impedance descriptions is developed and demonstrated for the cavitating finite length-bearing impedances. Analytic expressions are provided for all direct and cross-coupled stiffness and damping coefficients, and compared to previously developed numerical results. These coefficients are used for stability analysis of a rotor, supported in finite-length cavitating bearings. Onset-speed-of-instability results are presented as a function of the L/D ratio for a range of bearing numbers. Damping coefficients are also presented for finite-length squeeze-film dampers.

Diversity of bacterial populations in the Beaufort Sea

Abstract: BIOLOGICAL communities usually contain few species with many individuals and many species with few individuals1. Diversity of higher organisms generally has been found to decrease with increasing population size1. Communities in physically stressed ecosystems, such as in polar regions, characteristically have low species diversity2. Diversity indices have been used to express species diversity in plant and animal communities, especially as a measure of stress on community structure2. Amongst microorganisms, diversity indices have been applied to microscopic phytoplankton populations3,4, but not to bacterial populations. Bacterial populations, however, show large variations in species diversity. For example, infections are dominated by one or a few species, whereas many bacterial species are found in an ecosystem such as soil5. We report here the application of taxonomic diversity indices to bacterial populations and a study of the relationship of the diversity indices of such populations to population size and to population-independent factors such as geographic location.

Exercise Recovery, Lactate Removal, and Subsequent High Intensity Exercise Performance.

Abstract: In order to examine the effects of different recoveries from high intensity short duration exercise on lactate removal and subsequent performance, 11 subjects completed 8 experimental sessions. Each subject completed an initial all-out pedaling task against 5.5 kg resistance (Monark bicycle ergometer) for 1 min followed by a randomly assigned recovery pattern and a repeat of the all-out exercise task. The main effects examined were active (1.0 kg, 60 rpm) vs passive recovery, inhalation of inhalation of oxygen vs room air during recovery, and 10- vs-20-min duration of recovery. Pedal revolutions were analyzed on a 6- by 6-sec and on a cumulative basis. Blood lactate concentrations were determined during rest, the 3rd–4th, 9th–10th, and 19th–20th min of recovery. Results revealed significant main effects for active vs passive recovery and for 10- vs 20-min recovery, with active and 20-min recovery resulting in significantly higher postrecovery pedal revolutions (p < .001) and enhanced rates of lac...

Personal memories at different ages

Abstract: Men and women aged between 25 and 75 were asked to associate personal experiences to a set of 50 randomly chosen common words. The dates of these experiences were reconstructed and plotted as frequ...

Protective effects of passively transferred immune T- or B-lymphocytes in mice infected with Salmonella typhimurium.

Abstract: Purified populations of bone marrow-derived (B-) lymphocytes and thymus-derived (T-) lymphocytes were obtained from C3D2F1 hybrid mice shown to be immune to Salmonella typhimurium. These subpopulations of lymphocytes were injected into normal mice; four days later the animals were challenged with 50 50% lethal doses of S. typhimurium, and viable bacteria in livers, spleens, and blood were counted at various intervals after challenge. On day 8 after challenge, the mice supplemented with B-lymphocytes showed a significant decrease in the number of organisms recovered from all three sites, compared with that seen in recipients of T-lymphocytes and in controls. The mice given B-lymphocytes showed a better rate of survival (65%) than mice that received only T-lymphocytes (21%) or T-lymphocyte fractions contaminated 10%-30% with B-lymphocytes (49%). These data indicate that, although the humoral response is not totally protective, it does play an important role in the suppression of the infection during its early stages.

Optimal Test Characteristics for Maximal Anaerobic Work on the Bicycle Ergometer.

Abstract: Two separate experiments were conducted to ascertain the optimum protocol for a maximum anaerobic work output test on the bicycle ergometer. Data from 58 subjects indicated that the test duration needs to be approximately 40 sec and the optimal frictional resistance, 5.0 to 6.0 kp (30 to 36 kpm/rev). The desirability of using performance tests to represent biophysiologic data is discussed.

Tactual Distinctive Features Analysis: Training Blind Students in Shape Recognition and in Locating Shapes On a Map

Abstract: Two experiments were conducted to determine the effects of training blind students in shape recognition accuracy and speed and accuracy of locating shapes on a tactile map by using a distinctive features analysis strategy and line tracing. In Experiment 1, training significantly improved the shape-recognition performance of a group of 25 trained braille readers, as compared to a matched group of 25 untrained braille readers. In Experiment 2, 21 trained students (as compared to a matched group of 21 untrained students) showed a significant increase in the number of shapes located and a significant decrease in the average time to locate a shape on a tactile map. Results are discussed in terms of the critical importance of training blind students to be analytical, systematic, and complete in exploring tactile materials so as to ensure adequate development of their perceptual-conceptual abilities.

Continuous open flow-through system as a model for oil degradation in the arctic ocean.

Abstract: A continuous flow-through system incubated in situ was used to model oil biodegradation in Arctic coastal waters. High numbers of oil-degrading microorganisms were found in the Arctic coastal waters examined in this study. The microbial community underlying oil slicks increased and showed a population shift to a greater percentage of hydrocarbon-utilizing microorganisms. Microbial populations and oil biodegradation were increased by the addition of nitrogen and phosphorus. Both abiotic and biodegradative losses were lower than expected, perhaps due to the unusually harsh, ice-dominated Arctic summer, during which these tests were conducted. Chromatographic and spectrometric analyses showed that residual oils contained similar percentages of individual components and classes of hydrocarbons, regardless of the amount of degradation, indicating that most components of the oil were being degraded at similar rates.

Response of microorganisms to an accidental gasoline spillage in an arctic freshwater ecosystem.

Abstract: The response of microorganisms to an accidental spillage of 55,000 gallons of leaded gasoline into an Arctic freshwater lake was studied. Shifts in microbial populations were detected after the spillage, reflecting the migration pattern of the gasoline, enrichment for hydrocarbon utilizers, and selection for leaded-gasoline-tolerant microorganisms. Ratios of gasoline-tolerant/utilizing heterotrophs to "total" heterotrophs were found to be a sensitive indicator of the degree of hydrocarbon contamination. Respiration rates were elevated in the highly contaminated area, but did not reflect differences between moderately and lightly contaminated areas. Hydrocarbon biodegradation potential experiments showed that indigenous microorganisms could extensively convert hydrocarbons to CO(2). In situ measurement of gasoline degradation showed that, if untreated, sediment samples retained significant amounts of gasoline hydrocarbons including "volatile components" at the time the lake froze for the winter. Nutrient addition and bacterial inoculation resulted in enhanced biodegradative losses, significantly reducing the amount of residual hydrocarbons. Enhanced biodegradation, however, resulted in the appearance of compounds not detected in the gasoline. Since the contaminated lake serves as a drinking water supply, treatment to enhance microbial removal of much of the remaining gasoline still may be advisable.

Progesterone Binding to Serum Proteins

Abstract: Progesterone is bound in the blood serum of humans and most other mammalian species to three proteins: albumin; corticosteroid-binding globulin (CBG), or transcortin; and a,-acid glycoprotein (AAG), or orosomucoid. Whereas human serum albumin (HSA) consists of a folded polypeptide chain free of carbohydrate, AAG and CBG are glycoproteins with relatively high sugar content (TABLE I ) . The binding of the steroid hormones to the serum proteins is mediated essentially by hydrophobic forces and hydrogen bonds; noncovalent complexes are formed that are dissociable. The rate of dissociation increases with rising temperature. An inverse relationship exists between the serum concentrations of the three proteins and their affinity for progesterone. The association constant of CBG for progesterone at 37°C is approximately 500 times higher than that of HSA, but there are about 800 HSA molecules for each molecule of CBG in normal blood serum. This is the reason why the participation of HSA in the binding of steroid hormones is substantial'J; about half of the progesterone in pregnancy serum is associated with albumin (TABLE 2). A smaller percentage is albumin bound in the case of cortisol, a steroid of more hydrophilic nature than is progesterone. The biologic significance of protein binding of the steroid hormones3 is seen in several ways. The steroids are being transported by the serum proteins. This function does not include, however, the need for solubilization. because the maximal levels4 of even the least soluble progesterone are within the limits of aqueous solub i l i t ~ . ~ An important aspect of the protein complex formation is the protection of the steroid hormones from chemical or enzymatic attack, resulting in decreased metabolic clearance. This steroid-conserving mechanism has been emphasized recently6 for the progesterone-binding globulin (PBG) of the pregnant guinea pig, a serum glycoprotein to be discussed below. The steroids are biologically inactive as long as they are associated with protein; they can be \"activated\" by dissociation to the unbound hormone. In this manner, a relatively large amount of steroid can be carried in an indifferent storage form and can be made available immediately at the target tissue. For progesterone, nearly all of the hormone circulates in the body as a biologically inactive species (TABLE 2). The most desirable objective of the study of steroid hormone interaction with proteins would be the investigation of steroid receptor Unfortunately, none of these receptors has been available in purified form in sufficient amounts to make such study practical. Therefore, we have concentrated our efforts on the exploration of the chemical basis for the interaction of steroid hormones with serum proteins, preferably those of high affinity and specificity. Earlier results from our and other laboratories on the binding of progesterone to the three human proteins

Diurnal variations in the analgesic effectiveness of morphine in mice

Abstract: Response to thermal stimulation and the analgesic effectiveness of morphine during various phases of the diurnal cycle were assessed by the hotplate method. Saline treated controls exhibited shortest reaction times during the last quarter of the light-phase and first quarter of the dark phase. Longest reaction times were recorded during the last quarter of the dark phase. Doses of 4, 8, 16, and 32 mg/kg of morphine was administere IP at the peak and trough of the pain sensitivity rhythm. The ED5 0 (95% C.L.) during the last quarter of the light phase was found to be 14.60 (10.6–20.0) mg/kg while during the last quarter of the dark phase the ED5 0 was found to be 5.85 (4.5–7.7) mg/kg. In a second experiment, independent groups of ten mice each were injected SC with 8 mg/kg of morphine at three hr intervals over a 48 hr test session. Peak analgesic activity was obtained in the group injected during the last quarter of the dark phase while minimal analgesic effectiveness was obtained during the third quarter of the light phase. Central administration of morphine via the intraventricular route yielded the same relationship, i.e., maximal analgesic effectiveness during the last quarter of the dark phase.

Habitat and substrate influences on population and production dynamics of a stream caddisfly, Ceraclea ancylus (Leptoceridae)

Abstract: SUMMARY. Population and production dynamics of Ceraclea ancylus (Vorhies), a leptocerid caddisfly with a univoltine life cycle, five larval instars, and a single cohort population, were examined in Brashears Creek, Kentucky. A systematic sampling approach that included analysis in riffle, pool, and waterwillow bed habitats was used and fourteen sampling transects were taken across Brashears Creek between May 1971 and July 1972. For each of the 70 m2 samples taken along a transect, the depth, habitat, and substrate type were recorded. The number of C. ancylus cases and numbers and dry weights of each larval instar were determined. The majority of the C. ancylus population was in the second larval instar in July, the third larval instar in August, the fourth larval instar in September, and the fifth larval instar from October through May. The spring population was 30% of the early instar maximum estimated the previous August. The spatial distribution of C. ancylus reflects a logarithmic pattern with early instar larvae more highly clumped than the late larval instar and pupal populations. Initial standing stock estimates were less than 1% of the standing stock biomass. A production estimate of 9.9 mg/m2·year (dry weight) was determined using the instantaneous growth method, Allen's Curve method, and the Hynes method of estimating secondary production. Turnover ratios (7.0 annual TR, 5.7 cohort TR) were higher than estimates reported as typical for benthic macroinvertebrates because of the low initial to final mean individual weight of the C. ancylus larvae (0.4%). Production estimates calculated for C. ancylus populations in waterwillow bed (4.4 mg/m2·year) and pool (13.7 mg/m2·year) habitats were less than calculated for the riffle population (19.9 mg/m2·year). The annual turnover ratio (10.2) was higher in the pool population than in other habitats because of spring larval migration into the pool from other habitats. A trend of higher production estimates with larger sized substrate particles and increased numbers of particles may reflect the increase in available food sources or attachment sites. The accuracy of production estimates and their applicability to water resource management may be limited by a failure to consider the spatial distributions of the population being sampled and the tendency for sampling procedures to be confined to single habitats.