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Biomedical subjects

D C Smith

Publications and source records attributed to D C Smith.

533 records · Page 30Linked to original sources
PubMedDate not supplied

Three new low-osmolality contrast agents: a comparative study of patient discomfort.

Relative patient discomfort resulting from carotid injections of three new low-osmolality contrast agents was assessed in 78 patients. Omnipaque-300 (iohexol), Isovue-300 (iopamidol), and hexabrix (ioxaglate) were sequentially injected into both common carotid arteries of each patient. Patients were asked to rank the relative intensities of the three injections on each side. Mean patient rankings revealed that Hexabrix was preferred most often, Omnipaque-300 next, and Isovue-300 the least. The differences are statistically significant. We conclude that while patients usually tolerated all intracarotid low-osmolality contrast agents rather well, the agent preferred most often was Hexabrix.

Adult↗
PubMedDate not supplied

Ultrastructural morphometric data of human spermatozoa.

A morphometric study of the volumetric parameters of human spermatozoa has been carried out, volume densities being obtained by point counting and converted to absolute volumes by employing the point-sampled intercept method. Data for the Spermatozoa from the semen of 15 recently fertile men are presented. The significance of the results is discussed in relation to results obtained by other methods and in relation to the building of a diagnostic reference database.

Humans↗
PubMedDate not supplied

Subclavian steal with ipsilateral vertebral artery occlusive disease.

The classical subclavian steal syndrome is a larcenous vertebrobasilar insufficiency, secondary to retrograde flow in the vertebral artery. The authors present their experience with an unusual variant of subclavian steal in which the ipsilateral vertebral artery was completely or partially occluded, or arose from the aortic arch. These patients had symptoms typical of vertebrobasilar insufficiency--dizziness or brain stem transient ischemic attacks--despite steal through relatively small cervical collaterals to the obstructed subclavian artery. Physical findings of diminished pulses and blood pressure in the involved upper extremity are similar to those in the common form of subclavian steal. The alternate collaterals found in these patients are documented by angiography and other potential collaterals are reviewed. All three symptomatic patients were treated successfully by carotid-subclavian bypass or anastomosis of the subclavian to the common carotid artery. They have remained asymptomatic for 1 1/2 to 3 years following operation. The potential for development of subclavian steal in the absence of a vertebral artery to provide collateral flow adds another reason for abandoning vertebral artery ligation as an alternative treatment for the subclavian steal syndrome.

Aged↗
PubMedDate not supplied

Adjustable sliding aluminum wedge filter: device for angiographic enhancement.

Since the human body is of neither uniform thickness nor uniform composition, opacified vessels may be optimally exposed on a portion of the radiograph and overexposed on an adjacent portion. This unwanted nonuniformity in image darkness can be eliminated or reduced using a so-called compensating filter. In this paper such a filter in the form of an adjustable sliding aluminum wedge, that has been employed in angiographic procedures in our laboratory for the past four years, is described. The application of this filter to angiograms of various body parts is illustrated with clinical examples.

Aluminum↗
PubMedDate not supplied

Treatment of recurrent heart rejection with mycophenolate mofetil (RS-61443): initial clinical experience.

Mycophenolate mofetil (RS-61443), a derivative of mycophenolic acid, is a new immunosuppressive agent that inhibits de novo purine synthesis in activated lymphocytes. In a clinical trial of mycophenolate mofetil in the treatment of recurrent or persistent heart rejection, 17 patients 0.6 to 104 months (median 5.4 months) after transplantation received a daily oral dose of mycophenolate mofetil of 3000 mg, with seven patients increasing to 3500 mg daily. Azathioprine was routinely discontinued at the start of mycophenolate mofetil treatment. One patient in shock from acute rejection required retransplantation before starting mycophenolate mofetil and died 68 days later of cytomegalovirus sepsis. Another patient died 72 days after mycophenolate mofetil of protracted multisystem failure (present before mycophenolate mofetil). One patient required early cessation of mycophenolate mofetil, and the other 14 patients were alive and well 5 to 10 months after initiating mycophenolate mofetil treatment. Three patients required transient dose reduction and one patient required discontinuation of mycophenolate mofetil because of nausea, diarrhea, or abdominal cramps. No other clinical side effects were noted. Frequency of rejection decreased from 0.67 rejection episodes per patient per month before mycophenolate mofetil to 0.27 rejection episodes per patient per month after mycophenolate mofetil (p < 0.0001). Frequency of infection was unchanged after mycophenolate mofetil (p = 0.9). Renal function was not affected by mycophenolate mofetil (creatinine clearance 1.8 mg/dl before mycophenolate mofetil vs 1.7 mg/dl after mycophenolate mofetil; p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMedDate not supplied

Dental implants: materials and design considerations.

Although the biologic principles underlying successful clinical implants are still not completely understood, it is clear that both physical and chemical attributes of the material may influence the clinical outcome. Knowledge of the stresses and strains in an implant system and superstructure is still incomplete, but micromotion at the interface must be avoided for bone fixation. The composition and topography of the implant surface influence the cellular events at the bone-biomaterial interface. These surface parameters require definition to interpret the tissue response to a particular material. Hydroxyapatite-coated surfaces are an example of a variable implant modality that has resulted in variable clinical performance. The clinician should consider all the available information on material and design before embarking on extensive clinical trial.

Biocompatible Materials↗
PubMedDate not supplied

A prospective clinical study in humans of an endosseous dental implant partially covered with a powder-sintered porous coating: 3- to 4-year results.

A dental implant covered partially with a porous coating (EndoPore) developed at the University of Toronto was tested. This new implant is a tapered, truncated-cone endosseous root-form implant fabricated from Ti-6Al-4V. It utilizes a powder-sintered porous surface geometry over most of its length to promote three-dimensional bone ingrowth and implant stabilization. In this trial, three implants were placed in the anterior mandibles of 52 patients and were used subsequently as free-standing units to support an overdenture. Much shorter implants, shorter initial healing periods, and simpler surgical techniques than are customary with other implant designs were used. At the time of this report, all patients with implants had passed 3 years of function, and the cumulative implant success rate was 94.8%. Analysis of carefully standardized radiographs revealed a pattern of crestal bone loss similar to earlier published dog data. On a yearly basis, the mean bone loss was 0.43 mm in year 1, 0.17 mm in year 2, and 0.13 mm in year 3.

Adult↗
PubMedDate not supplied

Systemic metal ion levels in dental implant patients.

Metal ion release from metallic implants is known to occur, but its extent and implications are controversial. In spite of the rapidly growing use of such implants, little is known about metal ion release. Blood levels of titanium, aluminum, and vanadium were measured using an atomic absorption spectrophotometric technique preoperatively and at intervals over a 3-year period for 52 patients (17 men, 35 women), each of whom had three mandibular porous-surface endosseous dental implants. The results showed that there was no evidence of change from preoperative to long-term values for the three metals measured in the study. These findings are reassuring, but do not rule out local or remote accumulation of released ions, which was not measured in this study.

Adult↗
PubMedDate not supplied

Quality-of-life evaluation in patients receiving treatment for advanced prostate cancer.

PURPOSE/OBJECTIVES: To evaluate the quality-of-life (QOL) experience in patients who are receiving treatment for advanced prostate cancer and the relationship between response to that treatment and QOL. DESIGN: Descriptive comparative study, repeated measures. SETTING: Medical oncology clinic in a comprehensive cancer center. SAMPLE: 33 patients receiving treatment for advanced prostate cancer. METHODS: Patient self-administered questionnaires and chart review. MAIN RESEARCH VARIABLES: Response to therapy and QOL. FINDINGS: No significant differences were seen in patients at the baseline evaluation. Patients who demonstrated response to therapy based on declining prostate specific antigen levels, however, demonstrated a significant increase in their QOL scores compared to those patients who were not responding to treatment. CONCLUSIONS: Although significant differences in survival at this stage of prostate cancer in patients who receive therapeutic treatment versus those who do not have yet to be demonstrated, there appears to be a benefit in QOL for those patients who respond to therapy. IMPLICATIONS FOR NURSING PRACTICE: These data support the use of QOL measurements in patients undergoing treatment for advanced prostate cancer. This information can be used in discussions with patients who are facing treatment decisions and who are concerned about the impact of treatment on their overall QOL. The data also stimulate questions for future research on QOL in this population, such as the difference in QOL in those patients who choose therapeutic treatment versus those who do not.

Aged↗