Biomedical subjects

T W Chow

Publications and source records attributed to T W Chow.

78 records · Page 5Linked to original sources

PubMedDate not supplied

Direct detection of red blood cell fragments: a new flow cytometric method to evaluate hemolysis in blood pumps.

Pump induced hemolysis is presently evaluated by measuring plasma free hemoglobin (fHb). However, this method has disadvantages because quantification of fHb depends on hematocrit (HCT) and hemoglobin (Hb) levels. The aim of this work was to devise a hemoglobin independent method, capable of quantifying cell trauma directly by measuring the number of red blood cell (RBC) fragments. Whole blood flow cytometry was used to quantify circulating RBC fragments derived from a roller pump (Sarns, Inc. Model 2 M 6,002) and a centrifugal pump (Gyro C1E3, Kyocera Corp.). The pumps were tested in a mock circuit for 2 hr (5 L/min flow against 100 mm Hg pressure head). Red blood cell fragments were quantified by a phycoerythrin (PE) labeled glycophorin A antibody specific for erythrocytes. Red blood cell fragments were smaller than the intact RBC population and overlapped in size with the platelet population (based on forward- and side-light scattering measurements). For the roller pump, the values for RBC fragments increased from 1,090 +/- 260/microl at 0 min to 14,880 +/- 5,900/microl after 120 min. In contrast, using the centrifugal pump, there was little increase in RBC fragments (from 730 +/- 270/microl at 0 min to 1,400 +/- 840/microl after 120 min). Flow cytometry can be used for the rapid, sensitive, hemoglobin independent evaluation of pump induced RBC trauma.

Erythrocytes↗

PubMedDate not supplied

Clinicopathological concordance of dementia diagnoses by community versus tertiary care clinicians.

Subjects enrolled in the Autopsy Program at the University of Southern California Alzheimer's Disease Research Center may receive clinical diagnoses from primary care providers in the community or from specialists in neurology. We reviewed the autopsy concordance rates for 463 subjects for diagnoses made by both groups of clinicians. Seventy-seven percent of the sample met neuropathological criteria for Alzheimer's disease (AD). The overall diagnostic accuracy for this sample was 81 percent. Neurologists assessed 200 of the subjects (43 percent). The diagnostic accuracy for any clinical diagnosis among the non-neurologists was 84 percent, and 78 percent (p = 0.07) among neurologists. For AD, non-neurologists had a diagnostic concordance rate of 91 percent and neurologists 87 percent. Where neuropathological AD was missed, non-neurologists had failed to detect any cognitive impairment; neurologists had diagnosed Parkinson's disease (PD) and amyotrophic lateral sclerosis (ALS). Erroneous clinical diagnoses of AD missed dementia with Lewy bodies (DLB) or AD concurrent with Parkinson's disease (PD). Our findings identify specific foci for improving clinical diagnosis of dementia among all physicians managing dementia.

Adult↗

PubMedDate not supplied

The specialty of family dentistry: a future for general dental practitioners?

A new Specialty in dentistry, Family Dentistry, has been established to provide a structured, co-ordinated training for general dental practitioners who are the major oral health service providers. The training emphasizes the importance of continuing and comprehensive care, the interface between primary and secondary care, the relationship between the patient and his/her family and the community, and a holistic approach in treatment planning and delivery.

Comprehensive Dental Care↗

PubMedDate not supplied

Peri-implant bone loss: management of a patient.

This clinical report presents the prosthodontic management of early peri-implant bone loss in a partially edentulous patient. Two narrow Brånemark implants (3.3 mm in diameter) were placed to retain a mandibular implant prosthesis in the area of the mandibular left second premolar and first molar. Two weeks after the prosthesis was put into function, the distal implant exhibited soft tissue reactions. Radiographically, bone corresponding to 4 threads and 7 threads was lost at the mesial and distal sites, respectively. After occlusal load reduction was made to the existing prosthesis, bone was observed to have regenerated sufficiently to restore the defect radiographically, though not to the original level. The bone remained at a similar level at 36 months after treatment.

Adult↗

PubMedDate not supplied

Esthetic designs of removable partial dentures.

The increased emphasis on physical appearance in contemporary society has increased the demand for esthetic dental restorations. Although the success of implant dentistry has expanded the scope of esthetic fixed prostheses, many patients demand a removable partial denture (RPD) for health, anatomic, psychological, or financial reasons. Fabricating an esthetically pleasing RPD while avoiding the unsightly display associated with conventional clasp assemblies often presents a challenge to dentists. This article examines using lingual clasps, proximal undercuts (also known as rotational path insertion), and acetal resin clasps as simple and effective means of improving RPD esthetics.

Adult↗

PubMedDate not supplied

Denture base reinforcement using woven polyethylene fiber.

Reinforcement of acrylic denture base resin with high-performance polyethylene fiber in woven form produced a substantial improvement of stiffness and impact strength, as well as reducing the sensitivity of the material to notches that mimic anatomic features. The mechanical properties of the new systems were not affected by water immersion. Reinforced complete maxillary and mandibular dentures having good appearance and satisfactory fiber/resin integration were achieved using conventional laboratory techniques. These prostheses are undergoing clinical trials with encouraging results.

Analysis of Variance↗