Current studies on the location and function of carbonic anhydrase in osteoclasts.
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Aging↗
Biomedical subjects
R E Anderson
Publications and source records attributed to R E Anderson.
Localization of carbonic anhydrase in the cerebrum and cerebellum of normal and audiogenic seizure mice.
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Acoustic Stimulation↗
CT-guided stereotactic neurosurgery: experience in 24 cases with a new stereotactic system.
Twenty-four cases have been operated upon using a prototype Brown-Roberts-Wells, CT-guided stereotactic neurosurgical system. This device has proved to be practical and flexible in clinical use. No CT scanner modifications were required, a fact which simplified its use in more than one hospital. Multiple targets can be biopsied with ease and relative safety. Drainage and other therapeutic procedures can be carried out with minimal hazard. Future applications of this system may include its use with NMR and PET images.
Biopsy↗
Real-time digitally subtracted fluoroscopy for cervical myelography.
Improved visualization of the initial bolus of contrast material injected via a lateral Cl-2 puncture for cervical myelography can be obtained by using real-time digital subtraction fluoroscopy. As little as 0.1 ml of metrizamide (250 mg%) can be demonstrated easily.
Fluoroscopy↗
Computer-assisted morphometric analysis of late renal radiation injury.
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Animals↗
Lipid peroxidation and retinal degeneration.
Retinal degenerations were produced in albino rats by exposure to constant illumination or in frogs and albino rats by intravitreal injections of ferrous sulfate. Both treatments resulted in the loss of long-chain polyunsaturated fatty acids and the accumulation of lipid hydroperoxides in isolated rod outer segments. We suggest that lipid peroxidation is a factor in certain types of retinal degenerations.
Animals↗
Characterization of glutathione peroxidase in frog retina.
The properties and kinetic parameters of glutathione peroxidase were measured in retinal homogenates from frogs (R. pipiens) using a spectrophotometric assay in which the oxidation of glutathione is coupled to the oxidation of NADPH+ by exogenous glutathione reductase. The standard assay utilized 5.0 mM glutathione and 0.6 mM cumene hydroperoxide in 50 mM sodium phosphate buffer at pH 7.0. All solutions were bubbled with argon and all reactions were carried out under an atmosphere of argon. The enzyme activity was linear with protein concentration at different concentrations of both substrates. Determination of the pH optimum was complicated by a large increase in non-enzymatic oxidation of glutathione at alkaline pH. The highest ratio of enzymatic to non-enzymatic activity was at pH 7.0. Increasing glutathione concentration showed less effect on the spontaneous reaction than increasing the cumene hydroperoxide concentration. Glutathione peroxidase Km value for glutathione was 3.86 mM and for cumene hydroperoxide was 0.55 mM. Vmax for glutathione at 0.6 mM cumene hydroperoxide was 138 nmoles glutathione oxidized/min/mg protein, while at 5.0 mM glutathione the value for cumene hydroperoxide was 146 nmoles glutathione oxidized/min/mg protein. These studies demonstrate that glutathione peroxidase is active in the retina and establish the optimal experimental conditions for determination of the enzymatic activity.
Animals↗
The Nd:YAG laser in neurosurgery. Part 1. Laboratory investigations: dose-related biological response of neural tissue.
The biological response of normal cat brain to Nd:YAG laser light was studied both in vitro and in vivo to evaluate the potential safety of this laser for coagulation in brain tissue. Transmission studies revealed a blood:brain absorption ratio of 100:1 indicating the selective absorption of Nd:YAG light by hemoglobin and enabling Nd:YAG light to selectively heat blood vessels compared to brain tissue. In vivo temperature recordings and pathological evaluation demonstrated a remarkable ability of the brain to dissipate the thermal energy produced by Nd:YAG light with only a small amount of structural damage. Powers of 10 W applied for 8 seconds using a 1.2-mm focused probe resulted in a penetration depth in normal brain of only 2 mm. Thermal recordings also revealed that blood is heated to 90% of its maximum temperature within 3 seconds, while the brain temperature increases linearly as the duration of the laser pulse is increased. In addition, the localized heating of brain tissue was cooled rapidly within seconds following cessation of the laser pulse. These findings indicate that by using short, intermittent pulses of light focused upon blood vessels, damage to the surrounding tissue can be minimized, and the Nd:YAG laser can be used safely as an adjunctive measure for hemostasis in many neurosurgical procedures.
Animals↗
The Nd:YAG laser in neurosurgery. Part 2. Clinical studies: an adjunctive measure for hemostasis in resection of arteriovenous malformations.
The Nd:YAG laser has been used safely to aid in the resection of 10 cases of parenchymal arteriovenous malformations (AVM's). The laser was found helpful for: 1) defining the plane between the AVM and the brain; 2) coagulating any dural component of the AVM; and 3) achieving hemostasis of the bed following resection of the lesion. However, its overall benefit in the resection of AVM's remains to be determined, as it could not arrest active high-flow bleeding from the thin-walled vessels feeding the deep portion of the AVM. This was attributed to the inherent characteristics of these vessels, since the instrument has been effective in non-AVM arteries of similar dimensions containing contractile elements in the vessel walls. Future refinements in focusing instrumentation and operative technique should enhance its capabilities and usefulness. When used within the recommended power range, the Nd:YAG laser is safe and its penetration predictable. The fiberoptic cable light delivery system allows excellent mobility of the handpiece, but the protective eyewear laser-light filters reduce the available light to the surgeon. The instrument appears promising but more work is required.
Adolescent↗
A comparison of irradiation and mitomycin as blocking agents in the mixed lymphocyte reaction.
In comparison with administration of mitomycin, lethal irradiation (2,000 rad) of the stimulator cells in a one-way mixed leukocyte culture results in a reduced response due at least in part to the release of inhibitory materials by the irradiated cells. These inhibitory molecules may be partially removed by washing and possess differential reactivity with respect to phytohemagglutinin, concanavalin A, lipopolysaccharide, and pokeweed mitogen.
Animals↗
Parameters of hematoporphyrin derivative tumor cell killing efficiency: decomposition of hematoporphyrin derivative at high power densities.
Hematoporphyrin derivative (HpD) tumor cell killing efficiency has been evaluated as a function of power density, optical spectrum, HpD concentration, and HpD preparation using trypan blue exclusion assay. Cell survival curves for Mayo Clinic HpD and for Photofrin were equivalent at all concentrations and power densities for both violet and red light. Survival curves for red light demonstrated a two-fold increased cellular killing efficiency at higher densities (160 mW/cm2). However, for violet light an irreversible and marked decrease in cellular killing efficiency was found as the power density was increased. This phenomena of decreased cellular killing efficiency of violet light at high power densities is consistent with a process of photo-decomposition of HpD and is most pronounced at low concentrations (less than 25 micrograms/ml).
Cell Survival↗
The autopsy as an instrument of quality assessment. Classification of premortem and postmortem diagnostic discrepancies.
Use of the autopsy as an instrument of quality assessment of patient care requires the quantification of discrepancies between premortem and postmortem diagnoses and the determination of an acceptable range with respect to such differences. Factors believed to possibly influence the proportion of discrepant diagnoses were evaluated by way of a questionnaire mailed to 166 pathologists. Factors believed to be important include those related to the characteristics of the patient's illness, the patient's physician, and the setting in which the patient's care transpires . Responses from 127 persons, including 106 of those originally queried, suggested that assessment of patient care by way of the autopsy can best be accomplished on an institutional basis. Application of a categorization of discrepant diagnoses to several recent studies suggested that approximately 10% of hospital autopsies will yield missed major discrepant diagnoses associated with an adverse impact on survival.
Autopsy↗
Effects of irradiation on the interaction of fluorescent probes with lymphocytes.
Low doses of radiation reduce the rate and magnitude of fluorescent probe interaction with spleen cells. The uptake of 8-anilino-naphthalene sulfonic acid (ANS), but not diphenyl-hexatriene (DPH), is reduced in a dose-dependent fashion in cells that receive 25-100 rads. The effects of irradiation are most evident in a "medium" fluorescent subpopulation with no effect observed for a "dim" subpopulation. Splenic lymphocytes enriched for T cells show lower uptake of ANS, compared with a B-cell-enriched population. In addition, the normal decrease in ANS fluorescence polarization that occurs during the initial 10 minutes of probe interaction is attenuated in irradiated cells. These findings are consistent with the notion that low doses of radiation limit the penetration of ANS, but not DPH, into a less restrictive microenvironment within the plasma membranes of T, but not B, cells.
Anilino Naphthalenesulfonates↗
The fifth-year controversy.
Among the issues responsible for the current controversy surrounding a fifth year of training in pathology, the current division of authority and responsibility is paramount. In this article, approaches are recommended to resolve the acute problem and prevent comparable recurrences in the future.
Certification↗
Prognostic factors in invasive gallbladder carcinoma.
The medical records of 52 patients from the University of Wisconsin Hospital and Clinics with carcinoma of the gallbladder were examined retrospectively. The cases were reviewed for factors in their medical history, presenting physical examination, laboratory data, therapy, pathological grade, and histology that might effect median survival. Only a prior complaint of anorexia, an elevated lactic dehydrogenase (LDH), or advanced pathologic stage at time of diagnosis provided significant prognostic information. Combining pathologic stage and histologic grade additively provided the most significant prognostic information [1]. Division of gallbladder carcinoma patients in future clinical trials by this combined (stage and grade) stratification scheme may prove helpful in assessing the efficacy of new therapies. The knowledge that anorexia and elevated LDH are poor prognostic findings may assist physicians in counseling patients with this malignancy.
Aged↗
Hematoporphyrin derivative: quantitative uptake in dimethylhydrazine-induced murine colorectal carcinoma.
The selective affinity of hematoporphyrin derivative (HpD) for dimethyl-hydrazine-induced colorectal malignancies in mice was evaluated both visually and by a quantitative microfluorescent photometric technique. A significant correlation was found between higher concentrations of HpD in colon biopsies determined by microfluorescence spectroscopy and the presence of carcinoma cells in these biopsies as identified by histologic examination. Visual inspection of the gross fluorescence of tumor-bearing colons in this experimental model, however, was not helpful in differentiating malignant from nonmalignant tissue. The implications of this study regarding the clinical application of HpD tumor fluorescence for the detection of colorectal carcinoma are discussed.
Animals↗
Radiological aspects of CT-guided stereotactic neurosurgical procedures.
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Biopsy↗
Phospholipid molecular species of frog rod outer segment membranes.
Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were isolated from frog retinal rod outer segment (ROS) membranes and their major molecular species determined. Saturated fatty acids are predominantly located on position-1 and polyunsaturates on position-2, although this assignment is not absolute. One-fifth of the species of PC are of the saturated and monoenoic type, compared to only trace amounts of these species in PE. On the other hand, PE contains at least 50% dipolyunsaturated species, while PC has 6%. The predominant molecular species of frog PC are: 18:0-22:6 omega 3 (39%), 16:0-22:6 omega 3 (17%), 16:0-16:1 (6%), 16:0-18:1 (5%) and 16:0-16:0 (4%). The major molecular species of frog PE are: 22:6 omega 3-22:6 omega 3 (21%), 18:0-22:6 omega 3 (18%), 18:1-22:6 omega 3 (14%), 22:4 omega 6-22:6 omega 3 (10%), 22:5 omega (3 + 6)-22:6 omega 3 (10%), 16:0-22:6 omega 3 (7%) and 20:4 omega 6-22:6 omega 3 (5%). The specific molecular species are discussed in relation to their effect on fluidity and asymmetry of ROS disc membranes.
Animals↗