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Biomedical subjects

C R Taylor

Publications and source records attributed to C R Taylor.

At least 55 records · Page 3Linked to original sources
PubMed1998

Laser ignition of traumatically embedded firework debris.

BACKGROUND AND OBJECTIVE: The Q-switched ruby laser (QSRL) has a good track record for traumatic tattoo removal. An unusual case of QSRL-treatment of a traumatic tattoo composed of firework debris is presented. STUDY DESIGN/PATIENT AND METHOD: A young man's traumatic tattoo, composed of firework debris, underwent QSRL ablation at 4-7 J/cm2 (pulse width 5 mm; duration 20 ns). RESULTS: Each test pulse produced visible sparks and focal projectile ejection of skin with pox-like scar formation. CONCLUSION: Caution is advised when using the QSRL for the treatment of traumatic tattoos composed of potentially combustible debris.

Adult↗
PubMed1998

CO2 laser resurfacing of psoriatic plaques: a pilot study.

BACKGROUND AND OBJECTIVE: Laser resurfacing can precisely remove epidermis and papillary dermis, sites pivotal to the pathogenesis of psoriasis. Our objective was to determine the efficacy and safety of superficially ablating carbon dioxide (CO2) lasers for treating isolated, recalcitrant psoriatic plaques. MATERIALS AND METHODS: Twelve adult subjects with stable, plaque-type psoriasis were recruited. In six volunteers, the quadrants received different numbers of passes with a 60 microsec pulsed CO2 (Tru-Pulse) laser. In the remaining patients, one quadrant underwent curettage prior to resurfacing, the second resurfacing with a scanned continuous wave (Sharplan Silktouch) CO2 laser and the last curettage alone. RESULTS: Despite clinical and histological evidence of complete ablation of the epidermis and papillary dermis, most quadrants recurred within 8 weeks. Surprisingly, two patients showed no recurrence after 4 months. CONCLUSION: Ablation of the entire epidermis and papillary dermis with either pulsed or scanned CO2 lasers appears generally ineffective in treating recalcitrant psoriatic plaques, although the clearing seen in two patients suggests potentially successful future research directions.

Adolescent↗
PubMed1998

Solar urticaria: case report and phototesting with lasers.

Solar urticaria (SU) is a rare photosensitivity disease characterized by itching, erythema, and whealing immediately after exposure to sunlight or artificial radiation. A 28-year-old female whose history was strongly suggestive of SU, but who failed to demonstrate any photosensitivity on standard light testing with a slide projector as well as UVA and UVB broadband bulbs, developed urtication when provoked with the argon-pumped dye laser at 610 nm, 650 nm, and 690 nm. Lasers may be useful tools in performing visible phototesting, especially at longer wavelengths, in patients with SU because they are powerful and efficient, whereas slide projectors have relatively little emission toward the red wavelengths and consequently may fail to evoke an urticarial response in patients, such as ours, with high-threshold, red light-induced SU.

Adult↗
PubMed1998

Antigen retrieval immunohistochemistry used for routinely processed celloidin-embedded human temporal bone sections: standardization and development.

The use of immunohistochemistry (IHC) in routinely processed celloidin-embedded human temporal bone section has created a fruitful field in understanding the pathogenesis and pathophysiology of the human inner ear at a molecular level since the early 1990s when the antigen retrieval (AR) technique was developed. This review article focuses on several critical technical issues of AR technique based predominantly on our experiences and suggestions concerning further development and standardization of AR-IHC for IHC study of human temporal bone section, as well as other tissues embedded in celloidin. Examples of using AR-IHC in human temporal bone sections collected include our unpublished data in order to indicate the potential utility of this novel method. Suggestions of further development of AR techniques are proposed for references and comments.

Collodion↗
PubMed1998

A new chemically modified chimeric TNT-3 monoclonal antibody directed against DNA for the radioimmunotherapy of solid tumors.

In the last several years, our laboratory has developed a new approach to the radioimmunotherapy of solid tumors, designated Tumor Necrosis Treatment (TNT), that exploits the presence of degenerating and necrotic cells within tumors by utilizing MAbs directed against universal, intracellular antigens. The first TNT MAb developed by our laboratory, designated TNT-1, was directed against nucleosomal determinants consisting of histone H1 and DNA. Since absolute tumor accretion of MAb is a critical determinant of antitumor efficacy in radioimmunotherapy, we sought to identify new antinuclear antibodies that displayed high tumor localization properties. In the present study, we describe a murine antinuclear antibody, TNT-3, which demonstrates 3-fold higher tumor uptake than TNT-1. Because of this characteristic, a chimeric derivative designated chTNT-3 was developed and evaluated for antigen binding and tumor targeting. ELISA studies using a series of nuclear antigens confirmed that TNT-3 is directed against single-stranded DNA and does not cross react with TNT-1. Immunohistology reveals predominantly nuclear staining reactivity in human tissues and tumors. Since it was shown by our laboratory that charge modification can significantly improve the pharmacokinetic performance of monoclonal antibodies, chTNT-3 was chemically modified with biotin to generate an improved therapeutic reagent designated chTNT-3/B. Comparative studies with unmodified MAb demonstrated that biotinylation significantly shortened its clearance time in mice and produced lower normal tissue levels, while maintaining an equal amount of uptake in tumor xenografts for up to 10 days. These in vivo characteristics suggest that chTNT-3/B is an improved TNT reagent for the radioimmunotherapy of solid tumors.

Animals↗
PubMed1998

Computed tomography in the initial evaluation of hemodynamically stable patients with blunt abdominal trauma: impact of severity of injury scale and technical factors on efficacy.

BACKGROUND: Although computed tomography is used widely in evaluating injuries from blunt abdominal trauma, grading of injuries does not reliably predict the need for intervention. Objective reporting is essential to evaluate accuracy and facilitate patient triage. We established and tested a five-point grading system for overall severity of injury. METHODS: A total of 392 computed tomographic trauma cases were objectively classified according to the type and severity of abdominal injuries, by two experienced radiologists. Interobserver variability between the original interpretation and the consensus of the film reviewers was evaluated. The computed tomographic grading system was measured against rate of admission, exploratory laparotomy, and further imaging. RESULTS: Patients with higher grades of injury on computed tomography were increasingly likely to have surgical management (odds ratio, 3.99; 95% confidence interval, 1.86-8.58; p < 0.0006), with sensitivity 100%, specificity 89.5% for level 2 injuries and higher. Although there was almost perfect agreement between the official interpretation and the reviewers' blinded consensus interpretation (raw agreement 84%, weighted kappa 0.86), indeterminate studies were reduced from 23% (16 of 67) to 12% (8 of 67) on review: these were more likely to have metallic or motion artifacts (5 of 16 vs. 1 of 51 p < 0.002). CONCLUSIONS: Standardizing reporting of injuries enhances accuracy, and grading eliminates equivocation. Diagnostic certainty in computed tomography of blunt abdominal trauma is reduced by motion and metallic artifacts.

Abdominal Injuries↗
PubMed1998

Energetics of bipedal running. I. Metabolic cost of generating force.

Similarly sized bipeds and quadrupeds use nearly the same amount of metabolic energy to run, despite dramatic differences in morphology and running mechanics. It has been shown that the rate of metabolic energy use in quadrupedal runners and bipedal hoppers can be predicted from just body weight and the time available to generate force as indicated by the duration of foot-ground contact. We tested whether this link between running mechanics and energetics also applies to running bipeds. We measured rates of energy consumption and times of foot contact for humans (mean body mass 78.88 kg) and five species of birds (mean body mass range 0.13-40.1 kg). We find that most (70-90%) of the increase in metabolic rate with speed in running bipeds can be explained by changes in the time available to generate force. The rate of force generation also explains differences in metabolic rate over the size range of birds measured. However, for a given rate of force generation, birds use on average 1.7 times more metabolic energy than quadrupeds. The rate of energy consumption for a given rate of force generation for humans is intermediate between that of birds and quadrupeds. These results support the idea that the cost of muscular force production determines the energy cost of running and suggest that bipedal runners use more energy for a given rate of force production because they require a greater volume of muscle to support their body weight.

Animals↗
PubMed1998

Energetics of bipedal running. II. Limb design and running mechanics.

Compared with quadrupeds, bipedal runners of the same weight have longer legs, take longer steps and can presumably use slower, more economical muscle fibers. One might predict that bipedal running is less expensive, but it is not. We hypothesized that bipeds recruit a larger volume of muscle to support their weight, eliminating the potential economy of longer legs and slower steps. To test our hypothesis, we calculated the relative volume of muscle needed to support body weight over a stride in small dogs (Canis familiaris) and wild turkeys (Meleagris gallopavo) of the same weight. First, we confirmed that turkeys and dogs use approximately the same amount of energy to run at the same speed, and found that turkeys take 1. 8-fold longer steps. Higher muscle forces and/or longer muscle fibers would require a greater volume of active muscle, since muscle volume is proportional to the product of force and fascicle length. We measured both mean fascicle length and mean mechanical advantage for limb extensor muscles. Turkeys generated approximately the same total muscle force to support their weight during running and used muscle fascicles that are on average 2.1 times as long as in dogs, thus requiring a 2.5-fold greater active muscle volume. The greater volume appears to offset the economy of slower rates of force generation, supporting our hypothesis and providing a simple explanation for why it costs the same to run on two and four legs.

Animals↗
PubMed1998

Photosensitivity: classification, diagnosis, and treatment.

Photosensitivity disorders are common. Phototoxicity due to excess ultraviolet exposure while on a photosensitizing drug and polymorphic light eruption are two frequent examples. Patients should be encouraged to consider Taylor's ABCDEs: Avoidance, Barrier creams, Clothing, Dihydroxyacetone, and Education.

Humans↗
PubMed1997

Working underground: respiratory adaptations in the blind mole rat.

Mole rats (Spalax ehrenbergi superspecies) perform the heavy work of digging their subterranean burrows in Israel under highly hypoxic/hypercapnic conditions. Unlike most other mammals, they can achieve high levels of metabolic rate under these conditions, while their metabolic rate at low work rates is depressed. We explored, by comparing mole rats with white rats, whether and how this is related to adaptations in the design of the respiratory system, which determines the transfer of O2 from the lung to muscle mitochondria. At the same body mass, mole rats were found to have a significantly smaller total skeletal muscle mass than ordinary white rats (-22%). In contrast, the fractional volume of muscle mitochondria was larger by 46%. As a consequence, both species had the same total amount of mitochondria and achieved, under normoxia, the same V(O2max). Whereas the O2 transport capacity of the blood was not different, we found a larger capillary density (+31%) in the mole rat muscle, resulting in a reduced diffusion distance to mitochondria. The structural pulmonary diffusing capacity for O2 was greater in the mole rat (+44%), thus facilitating O2 uptake in hypoxia. We conclude that structural adaptations in lung and muscle tissue improve O2 diffusion conditions and serve to maintain high metabolic rates in hypoxia but have no consequences for achieving V(O2max) under normoxic conditions.

Adaptation, Physiological↗
PubMed1997

Muscular force in running turkeys: the economy of minimizing work.

During running, muscles and tendons must absorb and release mechanical work to maintain the cyclic movements of the body and limbs, while also providing enough force to support the weight of the body. Direct measurements of force and fiber length in the lateral gastrocnemius muscle of running turkeys revealed that the stretch and recoil of tendon and muscle springs supply mechanical work while active muscle fibers produce high forces. During level running, the active muscle shortens little and performs little work but provides the force necessary to support body weight economically. Running economy is improved by muscles that act as active struts rather than working machines.

Animals↗
PubMed1997

Thrombospondin-1 expression in bladder cancer: association with p53 alterations, tumor angiogenesis, and tumor progression.

BACKGROUND: Thrombospondin-1 (TSP) is a 430-kd glycoprotein that is an important component of the extracellular matrix and is known to be a potent inhibitor of angiogenesis (i.e., formation of new blood vessels) both in vitro and in vivo. Several reports suggest that TSP possesses tumor suppressor function, possibly through its ability to inhibit tumor neovascularization. It has recently been shown that TSP expression is enhanced by the product of the p53 gene (also known as TP53). PURPOSE: We examined the role of TSP expression in tumor recurrence and overall survival in patients with invasive bladder cancer. We also examined the relationship between alterations in p53 protein expression, TSP expression, and tumor angiogenesis. METHODS: Tumors from 163 patients (with a median follow-up of 7.7 years) who underwent radical cystectomy for invasive transitional cell carcinoma of the bladder (63 patients with organ-confined disease and no lymph node involvement, 48 patients with extravesical extension of the disease and no lymph node involvement, and 52 patients with metastasis to regional lymph nodes) were examined for TSP expression by immunohistochemistry, utilizing monoclonal antibody MA-II, which recognizes an epitope in the amino-terminal region of TSP. For each tumor, microvessel density counts and p53 protein expression status (via immunohistochemistry) were also determined. TSP expression was graded as low, moderate, or high without knowledge of clinical outcome, p53 status, and microvessel density count; tumors with moderate and high TSP levels were considered as one group. Groups of patients were compared by Kaplan-Meier product limit estimates of overall survival, the complement of cumulative incidence curves for recurrence-free survival, and the stratified logrank test. Reported P values are two-sided. RESULTS: TSP expression was significantly associated with disease recurrence (P = .009) and overall survival (P = .023). Patients with low TSP expression exhibited increased recurrence rates and decreased overall survival. TSP expression was an independent predictor of disease recurrence (P = .002) and overall survival (P = .01) after stratifying for tumor stage, lymph node status, and histologic grade, but it was not independent of p53 status. TSP expression was significantly associated with p53 expression status (P = .001) and microvessel density counts (P = .001). Tumors with p53 alterations were significantly more likely to demonstrate low TSP expression, and tumors with low TSP expression were significantly more likely to demonstrate high microvessel density counts. Results of an analysis of variance were compatible with the hypothesis that p53 affects tumor angiogenesis by regulating the level of TSP expression. CONCLUSIONS AND IMPLICATIONS: These data support the concept that TSP may possess a tumor-inhibitory function. TSP may act, in part, through the regulation of tumor neovascularity. These results may also provide insight into one mechanism by which p53 exerts its tumor suppressor effects, i.e., through the control of tumor angiogenesis.

Adult↗
PubMed1997

Marginal zone B-cell lymphomas: an appraisal.

Although the Revised European-American Lymphoma Classification does not utilize the term monocytoid B-cell Lymphoma, there are numerous reasons to support its use in classifying lymphomas of so-called marginal zone B-cell type that contain a distinct population of malignant monocytoid B-cells. In addition, there are other B-cell lymphomas which have very distinctive morphological features, because they show multiple and very well demarcated histologies characterized by presence of cells that appear to be (1) malignant monocytoid B-cells and malignant follicular center cells, or (2) malignant monocytoid B-cells, malignant follicular center cells and malignant plasma cells, or (3) malignant monocytoid B-cells and malignant mantle cells. The neoplastic cells in each of the above three examples show identical light chain restriction and thus they are part of the same neoplastic clone. We believe that there are different types of precursor B-cells (memory or otherwise) for the above cells, and an arrest in differentiation of these precursor B-cells may readily explain the presence of these different morphological combinations. Recognition of these morphological types may lead to further awareness of the possibilities of the existence of multiple, linked pathways of differentiation for lymphoid cells including the possibility of different types of precursor B-cells. Furthermore, an understanding of the uniqueness of monocytoid B-cells would allow pathologists to use terminology that is less redundant and more precise.

Humans↗