Search PubMed⌕ Search

Biomedical subjects

M E Smith

Publications and source records attributed to M E Smith.

At least 271 records · Page 15Linked to original sources
PubMed1989

Frontal sinus osteoma.

Osteoma is the most common benign tumor of the nose and paranasal sinuses, and the frontal sinus is its most frequent location. This tumor may be discovered incidentally on radiographs or may enlarge to produce symptoms and, rarely, complications referable to its location near the orbit and anterior cranial vault. A series of 22 cases of frontal sinus osteoma treated at the UCLA Center for the Health Sciences is reviewed. The presenting symptoms of this tumor, patient examination, radiographic evaluation, diagnosis, and indications for surgical and nonsurgical management are discussed. Various surgical approaches are reviewed, with emphasis on the advantages and disadvantages of each technique. Issues at surgery include the location of the surgical incision, technique of sinus entry, tumor removal, status of the posterior sinus table, patency of the nasofrontal duct, sinus obliteration, and avoidance of cosmetic deformity. Patient outcomes are assessed and recommendations given based on our findings and experience.

Adolescent↗
PubMed1989

Otologic manifestations of AIDS: the otosyphilis connection.

Five cases of otosyphilis presenting in patients with HIV infection are discussed. The group is representative of the known stages of the disease, from asymptomatic carrier to the fully expressed immunodeficiency syndrome, and it is of relevance because otosyphilis appears to have developed at an accelerated rate from the primary infection. Four patients had been treated with penicillin 2 to 5 years previously and had a positive fluorescent treponemal antibody absorption (FTA-ABS) test. The fifth had concurrent neurosyphilis and was VDRL-test (Venereal Disease Research Laboratory) negative 2 years prior to the onset of symptoms. In all five patients, syphilis was in the latent stage. It is proposed that it is during this phase of the disease that HIV may alter its course and hasten the development of otosyphilis. It is also suggested that otosyphilis can present at any stage of HIV infection and should be considered in seropositive patients presenting with otologic complaints.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Oncology nurses' knowledge of graft-versus-host disease in bone marrow transplant patients.

Graft-versus-host disease (GVHD) is a serious complication of allogenic bone marrow transplantation. A descriptive study was conducted to determine oncology nurses' knowledge of GVHD in bone marrow transplant patients. The research question was: Do oncology nurses who participate in continuing education programs and read journal articles on GVHD have increased knowledge, as compared with oncology nurses who do not participate in these activities? Seventy-eight nurses completed a demographic data form and a GVHD questionnaire developed by the investigators (r = 0.71). Multiple regression analysis determined the relationships between independent and dependent variables. An analysis of variance determined a significant difference between the mean scores associated with the identified learning activities (F = 3.61, p less than 0.05). Continuing education activities and reading of journal articles were associated with higher knowledge scores (R2 = 0.1052, p less than 0.05). Many oncology nurses have no formal education in bone marrow transplantation and limited clinical experience with GVHD. Additional work must be done to determine if some oncology nurses practice from a weak theoretical framework and have limited rationales for their nursing actions. Further research, instrument development, and a teaching protocol on GVHD will enhance the nursing care needed by the patient with GVHD.

Bone Marrow Transplantation↗
PubMed1989

Furosemide: update on a commonly used drug.

Because of its efficacy, IV furosemide has become a common medication administered to the critically ill adult. It is capable of causing serious complications if given without caution, without prior assessment of the patient's clinical status, or without careful monitoring of response to therapy. Furosemide has the potential to cause problems that are more than fluid and electrolyte imbalances. The nurse must be aware of toxic effects and how to minimize them when giving higher doses and, in renal failure. It is imperative for a patient's progress that his or her nurses have a knowledgeable and respectful attitude toward the drugs they administer.

Critical Care↗
PubMed1989

Pharmacokinetics and bioavailability of Sinemet CR: a summary of human studies.

The pharmacokinetics of Sinemet CR, a controlled-release formulation containing carbidopa and levodopa, were investigated in healthy young and elderly volunteers and in patients with Parkinson's disease. Sinemet CR produced more sustained plasma levels of levodopa, carbidopa, and 3-O methyldopa than did conventional Sinemet. In elderly subjects, the corresponding steady-state plasma levels fluctuated in narrower ranges with Sinemet CR than those following the administration of Sinemet. Results indicate a levodopa bioavailability of 71% for Sinemet CR, in contrast to a bioavailability of 99% for Sinemet for these subjects. The carbidopa bioavailability of Sinemet CR was 58% relative to that of Sinemet. Systemic decarboxylase inhibition was comparable between the 2 regimens as indicated by the renal clearance of levodopa. The absorption of levodopa was slower and more protracted with Sinemet CR than with Sinemet. Food increased the levodopa bioavailability of Sinemet CR. This increase was attributed to an increased gastric retention time. No dose-dumping occurred with Sinemet CR in either the nonfasting or the fasting state. Levodopa bioavailability was lower in young volunteers than in elderly volunteers. This was attributed to an age-related decrease in gastric emptying and in 1st-pass metabolic decarboxylation in the gastrointestinal (GI) tract. In parkinsonian patients, as in healthy subjects, the Sinemet CR formulation produced more sustained levodopa plasma levels. These patients required a higher total daily dosage of Sinemet CR than of Sinemet for control of parkinsonian symptoms, but less frequent dosing was required during chronic therapy. Peak plasma levodopa levels increased proportionately with increasing Sinemet CR dosage. These observations were consistent with the pharmacokinetic characteristics of the formulation.

Adolescent↗
PubMed1989

Multicenter controlled study of Sinemet CR vs Sinemet (25/100) in advanced Parkinson's disease.

Controlled-release carbidopa/levodopa 50/200 (Sinemet CR) and standard carbidopa/levodopa (Sinemet 25/100) were compared in a multicenter double-blind trial involving 202 patients with advanced Parkinson's disease and motor response fluctuations. Treatment with Sinemet CR significantly reduced daily "off" time. According to both physician and patient global ratings, patients showed significant improvements with Sinemet CR compared to treatment with standard Sinemet. Patients preferred Sinemet CR treatment by a ratio of approximately 2 to 1. Daily dosing frequency was 33% less with Sinemet CR, while daily intake of levodopa required was increased by 25%. The safety profiles of the 2 formulations were similar. We conclude that Sinemet CR is superior to standard Sinemet for many patients with advanced Parkinson's disease, although it does not solve the problem of fluctuating motor performance.

Aged↗
PubMed1988

Effect of nerve section on beta-endorphin and alpha-melanotropin immunoreactivity in motor nerves of normal and dystrophic mice.

beta-Endorphin and alpha-melanotropin immunoreactivity was demonstrated in some motor nerves in histological sections of soleus and extensor digitorum longus muscles of the mouse. In two strains (C57BL/6J and 129/ReJ) which can inherit muscular dystrophy, the proportion of immunoreactive nerves was greater in the dystrophic individuals than in their healthy littermates. At 24 h after section of the sciatic nerve in the normal mice the proportion of immunoreactive nerve profiles had increased significantly in the denervated muscles even though most of the nerve axons had degenerated. Similar increases were also seen in nerves in the unoperated contralateral muscles.

Animals↗
PubMed1988

Quantitative assay for evaluating immunocompetence and DNA repair capacity.

Incorporation of radioactive thymidine into newly synthesized DNA is the basis of an assay frequently used to study immunosuppression in cancer patients. It has also been used to measure the amount of excision repair performed by non-replicating cells damaged by carcinogens. For human lymphocytes (and probably other cell types), these assays are unreliable as they are currently being performed. We report a modified assay that allows accurate comparisons of the immunocompetence and DNA repair capacity of different individuals. With this assay, cells can be studied in their autologous plasma and the role of biological response modifiers can be assessed.

Autoradiography↗
PubMed1988

Neural encoding of individual words and faces by the human hippocampus and amygdala.

Patients with lesions in the medial temporal lobe (MTL) of the brain, which includes the hippocampus, amygdala and parahippocampal gyrus, are severely impaired in their ability to remember and recognize words or faces which they saw only a short time ago. These lesions also prevent the effect of word repetition on cortical event-related potentials that are associated with these tasks. We have been able to study the response of individual neurons in the human medial temporal lobe to such delayed recognition tasks in epileptic patients undergoing neurosurgery. We found that some MTL neurons preferentially fired on sight of one particular word from a set of ten words used in a memory task, and others fired in response to one particular face. This stimulus-specific firing was maximal during the time that the neocortical event potentials are most sensitive to stimulus repetition, suggesting that the MTL contributes specific information to the cortex during the retrieval of recent memories.

Action Potentials↗
PubMed1988

In vitro melanoma cell growth after preenucleation radiation therapy.

The in vitro efficacy of 20 Gy (2000 rad) of external beam irradiation delivered to patients with choroidal melanomas prior to enucleation was investigated in 11 patients whose tumors were grown in cell culture. Phase-contrast microscopy was used to compare growth patterns between irradiated and nonirradiated tumors. Cell types were determined by histologic stains, and electron microscopy identified intracytoplasmic melanin. Irradiated melanomas did not grow and did not attach to culture flasks, thus demonstrating that preenucleation irradiation alters the in vitro growth of melanoma cells.

Cell Adhesion↗
PubMed1988

Neurilemoma as a presenting feature of neurofibromatosis.

A previously healthy 38-year-old woman presented with gradually progressive ptosis and downward deviation of her left eye and a palpable left superonasal orbital mass. The mass was excised, and histopathologic examination revealed a tumor composed of spindle cells arranged in both Antoni A and B patterns. Presence of S-100 antigen was determined by immunoperoxidase staining. The diagnosis was neurilemoma. A right apical extraparenchymal mass detected on a preoperative chest roentgenogram and computed tomography was most consistent with a benign neurogenic tumor. The presentation was that of a recently discovered neurilemoma in a patient with preexisting, but previously undiagnosed, neurofibromatosis.

Adult↗
PubMed1988

CD1c antigens are present in normal and neoplastic B-cells.

The immunohistochemical detection of CD1c antigen is described in mantle zone B-cells of the tonsil, lymph node, and spleen, and also in the marginal zone B-cells of the spleen. CD1c expression was observed in most cases of low-grade, but in only a single case of high-grade, B-cell non-Hodgkin's lymphoma. It was not detected in germinal centre cells, nor in Epstein-Barr virus-transformed or Burkitt's lymphoma B-cell lines. This distribution suggests that CD1c expression may occur preferentially in slowly proliferating B-cell populations and does not support previous suggestions that CD1c is a human equivalent of the mouse thymus leukaemia antigens.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1988

Attenuation of a sustained visual processing negativity after lesions that include the inferotemporal cortex.

Prior studies have identified a sustained, posteriorly distributed 'processing negativity' related to visual attention and pattern recognition processes. In the present report, we document that such a negativity is elicited in a visual word classification task, and that it is disrupted following unilateral anterior temporal lobectomy for the treatment of epilepsy. For both right- and left-sided excisions the disruption is greatest on the side of surgery. These results are interpreted within theories of visual processing which attribute a role for the inferotemporal cortex (which is affected by anterior lobectomy) in pattern recognition, and they suggest that this region plays an important role in the generation of the visual processing negativity.

Adult↗
PubMed1988

Food preferences in families.

Preferences for a wide variety of foods were examined in families: 77 students, plus their siblings, mothers and fathers, for a total of 241 subjects. The food preferences of family members were more similar than would be expected by chance. However, this occurred entirely in the comparisons between spouses and between female family members. The results also indicated sex and age differences in family members' food preferences. For example, females tended to prefer low-calorie foods more when they were older, while males tended to prefer alcoholic beverages more when they were older. Both males and females showed a greater preference for coffee when they were older. Some of the variance in food preferences can be explained by an individual's family members' food preferences, as well as by the individual's sex and age.

Adolescent↗