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Biomedical subjects

J D Anderson

Publications and source records attributed to J D Anderson.

At least 73 records · Page 4Linked to original sources

An Ethylene Biosynthesis-Inducing Endoxylanase Elicits Electrolyte Leakage and Necrosis in Nicotiana tabacum cv Xanthi Leaves.

We have previously demonstrated that a protein purified from xylan-induced culture filtrates of Trichoderma viride contains beta-1,4-endoxylanase activity and induces ethylene biosynthesis in tobacco (Nicotiana tabacum cv Xanthi) leaf discs. When the ethylene biosynthesis-inducing xylanase (EIX) was applied to cut petioles of detached tobacco leaves, it induced ethylene biosynthesis within 1 hour and extensive electrolyte leakage and necrosis were observed in tobacco leaf tissue within 5 hours. Ethylene-pretreatment (120 microliters per liter ethylene for 14 hours) of tobacco leaves enhanced ethylene biosynthesis in response to EIX by more than threefold and accelerated development of cellular leakage and necrosis. In intact plants, similar symptoms could be induced in leaves that were distant from the point of the enzyme application. The evidence suggests that EIX is translocated via the vascular system and elicits plant responses similar to those observed in a hypersensitive response.

Journal Article↗

Monofilament nylon filters for preventing dracunculiasis: Durability and copepod retention after long term field use in Pakistan.

Filtration of drinking water to remove the cyclopoid copepod intermediate hosts of guinea worm. Dracunculus medinensis, is one of the primary intervention strategies for preventing dracunculiasis. In early 1987, monofilament nylon filters with 200 microns pore size were distributed to households in selected guinea worm-infected villages in Pakistan. The filters proved popular with the villagers, although reports of "loss of filters" could diminish the community-wide effectiveness of this control measure. After 12 to 15 months of usage a sample of these filters was collected and examined for damage or impairment which would decrease their use or their capacity to retain potentially infective copepods. Although all naupliar stages and early copepodids (Stages CI-II) passed through these used filters, the larger copepodids including adults (Stages CIII-VI) were retained despite small tears in the fabric. This field trial showed that after 12 to 15 months of regular use, monofilament nylon filters of 200 microns pore size remained effective in removing copepodid stages capable of supporting development of D. medinensis larvae. Considering the ease of use, popularity and effective filtration of potentially infective copepods following prolonged field use, we recommend that monofilament filters be considered in any program of guinea worm elimination.

Animals↗

Spouse adjustment to stroke: aphasic versus nonaphasic partners.

A survey of spouses of stroke patients examined the impact of stroke with and without aphasia on spouse role change, emotional problems, social adjustment, and the partner's perceived communication abilities. The results of this study support earlier findings that stroke with aphasia has a greater negative impact on the patient's spouse than does stroke without aphasia. For the spouses of aphasic patients sampled in this study, role changes represented the major adjustment made to a partner's stroke. These adjustments were greater than those experienced by the spouses of nonaphasic patients. The inability of aphasic patients to communicate well with their spouses served to make necessary role adjustments more difficult. Both spouse groups were affected to some degree by the communication problems associated with stroke, with the spouses of aphasic partners being affected the most.

Aphasia↗

Low dose combined chemotherapy/radiotherapy in the management of locally advanced urethral squamous cell carcinoma.

The successful treatment of a patient with bulky squamous cell carcinoma of the urethra using low dose preoperative radiation therapy and concurrent chemotherapy is described. Dramatic rapid tumor response facilitated surgical resection of the remaining microscopic disease. This clinical behavior is remarkably similar to that seen with squamous cell carcinoma of the anal canal and esophagus when a similar regimen is used. At the latter tumor sites the successful use of combination radiotherapy and chemotherapy has reduced the morbidity of subsequent surgery, and in selected cases has obviated the need for a radical operation. Further investigation of such combination treatment is warranted for urethral carcinoma.

Antineoplastic Combined Chemotherapy Protocols↗

Ethylene biosynthesis-inducing protein from cellulysin is an endoxylanase.

The proteinaceous ethylene biosynthesis-inducing factor (EIF) that was purified from Cellulysin was also shown to contain a xylanase activity. In all nondenaturing protein separation methods employed (Sephacryl S-200 chromatography, and preparative isoelectric focusing and agarose electrophoresis), xylanase activity copurified with the ethylene biosynthesis-inducing activity. Treatment with heat (60 degrees C) or proteases in 8 molar urea inhibited both ethylene-inducing and xylanase activities. Antibodies raised against purified EIF, which contains three polypeptides of 18, 14, and 10 kilodaltons, immunoprecipitated both ethylene biosynthesis-inducing and xylanase activities. The purified EIF contained no detectable cellulase, polygalacturonase, or protease activity. Other hydrolytic activities as estimated by using p-nitrophenyl derivatives of several sugars as substrates also were not detected. Different commercially available hydrolytic enzyme preparations were tested for both ethylene biosynthesis-inducing and xylanase activities. All enzymes tested contained xylanase activity, but only a few induced ethylene biosynthesis. Western blots of proteins separated by SDS-PAGE, using antibodies prepared against the non-denatured purified EIF, revealed two major bands of about 18 and 14 kilodaltons in EIF. These antibodies seem to be specific for these proteins from Trichoderma viride, because there was little cross-reactivity with the other proteins in Cellulysin and other commercial enzyme preparations. Based on these data, we suggest that EIF contains a specific xylanase activity which is involved in inducing ethylene biosynthesis.

Journal Article↗

Assessment of the BACTEC NR660 blood culture system for the detection of bacteremia in young children.

The sensitivity of the BACTEC NR660 blood culture system was assessed by using paired bottles of anaerobic (NR7A) and resin-containing aerobic (NR16A) media and conditions and organisms which simulated those found in pediatric practice. Corresponding media (7D and 16B) of the established BACTEC 460 radiometric method served as controls. The performances of the two systems were similar with 50 isolates of 10 aerobic organisms (aerobic medium) and with 21 isolates of 15 strict anaerobes (anaerobic medium).

Bacteria↗

Ocular trauma.

Well over half a million people in the world are blind as a result of eye injuries. It is not known how much of the final visual damage is the result of delayed or inappropriate management at the primary care level. However, it is certain that the outcome of ocular trauma by prompt action that will prevent serious loss of sight. He or she requires neither specialist knowledge, nor expensive instruments, but only the common sense application of a few basic clinical skills.

Burns, Chemical↗

The immediate role of the dentist in the maxillectomy patient.

It is imperative that comprehensive planning takes place for the potential maxillectomy patient. Input from the dentist is required for all stages of the procedure, from initial consultation to placement of the final prosthesis. By utilizing an interim dental prosthesis (splint), the impact of tissue loss, wound fibrosis and neurological damage can be minimized. In this paper, the authors address the initial stage in the treatment sequence, the surgical splint.

Humans↗

Prostatic carcinoma presenting with neck metastasis.

Prostatic carcinoma is the second leading cause of cancer mortality in American men. Twenty-seven thousand deaths from this aggressive neoplasm were predicted for 1987. Although this malignancy has metastasized to almost all of the structures in the head and neck, it demonstrates a pathophysiologic proclivity for the supraclavicular lymph nodes. Combining fine-needle aspiration with immunohistochemical techniques produces a cost-effective method to expedite the diagnosis of this hormone-responsive tumor. Four patients presenting with prostatic carcinoma and neck metastasis in a three-year period are reported and discussed.

Acid Phosphatase↗

The in-vitro assessment of a collagen/vicryl (polyglactin) composite film together with candidate suture materials for use in urinary tract surgery. II. Surface deposition of urinary salts.

Collagen coated vicryl mesh has been incubated with a series of urine collections from healthy and stone-forming patients. For comparison, collagen film, vicryl mesh, and a number of absorbable and non-absorbable sutures were similarly tested. Incubation in rabbit urine were also included in the study. Deposition of urinary salts, estimated qualitatively by electron microscopy, were observed on the collagen vicryl composite in approximately two thirds of the urines tested including rabbit urine. Those urines from patients with a high calcium excretion in particular caused urinary deposits on the material. Similar results were obtained with collagen film although the latter was not tested in rabbit urine. Considerably less deposits of urinary constituents were found with other absorbable materials such as vicryl mesh, vicryl sutures, and chromic catgut, whereas a higher proportion of concretions were found with the non-absorbable sutures. The results indicate that urinary salt deposition may be a problem associated with collagen based composite materials after prolonged exposure to urine. It must, however, be emphasised that great care should be exercised when extrapolating any results obtained in-vitro to the in-vivo situation.

Animals↗

Identification of a unique isoform of 1-aminocyclopropane-1-carboxylic acid synthase by monoclonal antibody.

1-Aminocyclopropane-1-carboxylic acid (ACC) synthase (EC 4.4.1.14) is a key enzyme regulating ethylene biosynthesis in higher plants. A monoclonal antibody (mAb T20C) that immunoprecipitates the ACC synthase activity from tomato pericarp tissue extracts revealed that mAb T20C immunodecorates an approximately 67-kDa polypeptide. On isoelectric focusing gels, ACC synthase activity in cell-free preparations was resolved into three distinct activity peaks with pI values 5.3, 7, and 9. mAb T20C specifically recognized the pI 7 form of the enzyme on electrophoretic transfer (Western) blots. When analyzed by sodium dodecyl sulfate gel electrophoresis under reducing conditions, the eluted pI 7 form was confirmed to migrate as a polypeptide of 67 kDa. The 67-kDa pI 7 isoform is a previously undescribed form of ACC synthase.

Journal Article↗

Animal evaluation of a new pericardial bioprosthetic heart valve.

Implantation in animals is an essential step in the evaluation of any new prosthetic heart valve before commencing clinical trials. A new three-leaflet pericardial bioprosthesis developed in Glasgow has been implanted in the mitral position in ten sheep and eight dogs. Eleven animals were electively killed after 3 months of observation and explanted valves were in good condition. Hydrodynamic tests of the explanted valves showed small changes in function compared to tests prior to implantation. This was mainly due to host tissue ingrowth over the edge of the leaflets. Histological studies confirmed good preservation of the pericardial tissue in explanted valves.

Animals↗