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Biomedical subjects

David Todd

Publications and source records attributed to David Todd.

7 recordsLinked to original sources
PubMed2004

Friction melanosis: a clinical, histologic, and ultrastructural study in Jordanian patients.

BACKGROUND: Friction melanosis (FM) is an acquired pigmentary disorder mainly affecting young people. The primary skin regions affected are located over the osseous prominences, especially the clavicular zone and upper back. Our purpose in this study was to report the clinical spectrum, histologic findings, and ultrastructural features of FM in Jordanian patients. METHODS: Thirteen patients with FM (10 women and three men) were studied. The patients were seen at Princess Basma Teaching Hospital in north Jordan between 1999 and 2001. RESULTS: Eleven patients presented with asymptomatic, diffuse, brownish patches and two presented with mottled patches on the skin over the trunk bones and limbs. All had a history of rubbing their skin repeatedly with scrub pads (loofah) or bathroom towels. Ten of the 13 cases were studied histologically. Skin biopsies from four patients were examined ultrastructurally. Both histologic and electron microscopic examination of the biopsies from our patients showed a marked increase in melanin and melanin incontinence, with a lack of amyloid in the upper dermis. CONCLUSIONS: FM is infrequently seen in north Jordan. We believe that repeated frictional trauma from clothing or scrub pads against the skin overlying the bony protuberances is fundamental in its pathogenesis. Other factors, such as scrub pads made of rough material (loofah), dark skin type, and individual variability, may also play a role in the pathogenesis. We advise patients not to use rough scrub pads during bathing, to avoid rubbing the skin overlying the bony prominences, to avoid rubbing vigorously, and to use a soft cotton pad instead.

Administration, Topical↗
PubMed2004

Pacemaker diagnostics to determine treatment and outcome in sick sinus syndrome with paroxysmal atrial fibrillation.

Sequential analysis of pacemaker diagnostics has been used to help manage the treatment and pacemaker program in patients who have sick sinus syndrome with documented paroxysmal atrial fibrillation. One hundred consecutive patients were followed for an average of 18 months. Knowledge of the atrial fibrillation burden led to major changes in medical management for half of the patients and changes to pacemaker programming for all. At the end of the study, 48 patients were free of arrhythmia with pacing although 14 required antiarrhythmic medication. We advocate using pacemaker diagnostics to improve patient management.

Aged↗
PubMed2003

Pathologic evaluation of a spherical polyvinyl alcohol embolic agent in a porcine renal model.

PURPOSE: To evaluate the effects of a spherical embolic agent consisting of polyvinyl alcohol (PVA) and to compare this agent with commercially available embolization agents. MATERIALS AND METHODS: Eleven miniature pigs were included in the study population. The upper poles of both kidneys were selected as the target organs for embolization. PVA spheres (700-900 micro m) were used in nine kidneys, PVA particles (500-710 micro m) were used in six kidneys, gelatin spheres (700-900 micro m) were used in five kidneys, and gold-colored gelatin spheres (700-900 micro m) were used in three kidneys. Two animals were killed immediately after embolization. In the remaining animals, angiography was performed before sacrifice 7 days (in five pigs) or 28 days (in four pigs) after embolization. Pathologic and histologic evaluation of the kidneys was performed. RESULTS: All agents resulted in target vessel occlusion and end-organ infarction. All arteries embolized with spherical agents were recanalized at follow-up angiography. In vessels embolized with PVA particles, the occluding plug consisted of thrombus and PVA. In vessels embolized with spherical agents, the occluding plug consisted mostly of the embolic agent. PVA spheres were associated with the mildest inflammatory responses at 7 and 28 days when compared with PVA particles and gelatin-based microspheres. Arterial wall destruction was seen to a greater extent in kidneys embolized with gelatin-based microspheres than in those embolized with PVA-based agents. CONCLUSIONS: The spherical, PVA-based embolization agent resulted in target organ infarction and temporary arterial occlusion. The inflammatory response to PVA spheres was significantly less aggressive than the response to other agents tested. Further study with clinical and long-term pathologic follow-up is suggested to determine if these findings may have favorable clinical implications for patients undergoing embolization procedures.

Angiography↗
PubMed2002

Early ambulation after diagnostic angiography using 4-f catheters and sheaths: a feasibility study.

PURPOSE: To assess the feasibility and safety of early ambulation in patients undergoing transfemoral diagnostic angiography using 4-F catheters or sheaths. METHODS: In this prospective study approved by the institutional review board, patients undergoing diagnostic angiography were randomized to ambulate 3 or 6 hours after catheter or sheath removal. All patients were assessed for hematoma formation, pseudoaneurysm development, and other groin complications during the in-hospital recovery period and after 30 days. Patient satisfaction and comfort level were also assessed by survey. RESULTS: Of 110 patients (66 men; mean age 64.9 +/- 12.8 years) who participated in this study, 47 were randomized to the 6-hour (6-H) group and 63 to the 3-hour (3-H) group. In the 3-H and 6-H groups, respectively, a 4-F catheter was used in 45 (71%) and 35 (74%) patients and a 4-F sheath in 18 (29%) and 12 (26%). No clinically significant groin complications were encountered in either group. Moderate to severe discomfort was reported in 9 (16%) of the 56 patients responding to the discomfort survey in the 3-H group compared to 10 (26%) of the 38 in the 6-H survey respondents. CONCLUSIONS: It is feasible and safe to ambulate patients 3 hours after diagnostic angiography performed with a 4-F catheter with or without a 4-F sheath. Early ambulation of patients after angiography has the additional benefits of increasing patient satisfaction and resource utilization.

Aged↗