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Biomedical subjects

J Pugh

Publications and source records attributed to J Pugh.

At least 55 records · Page 3Linked to original sources
PubMed1980

Subpopulations of human peripheral granulocyes and monocytes express receptors for IgA.

Receptors for the Fc portion of immunoglobin on human peripheral blood cells were enumerated by rosette formation with ox erythrocytes sensitized with rabbit IgG, IgA, and IgM. A large percentage of purified polymorphonuclear leukocytes and monocytes were found to express receptors for IgA. These receptors were also found to exist on a significantly greater percentage of lymphocytes than was previously observed. The receptors for IgA were specific, as verified by blocking studies using purified human immunogloblins. In addition, some polymorphonuclear leukocytes and monocytes were observed concomitantly to posses independent receptors for both IgG and IgA. These studies may indicate that IgA can cooperate with monocytes or polymorphonuclear leukocytes through receptors for IgA on these cells and perhaps mediate immune defense on mucosal surfaces. Initial studies on antibody-dependent cellular cytotoxicity suggested that IgA alone is ineffectual in supporting cytolysis by nonactivated human peripheral blood cells.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1979

The response of the lower extremity to impact forces. II. Computerized mechanical impedance measurements.

The preferred method for the noninvasive assessment of the mechanical properties of the musculoskeletal system is the measurement of mechanical impedance by means of an instrumented impact hammer and accelerometer. When coupled to an interactive computer system, this is shown to be a powerful tool in the quantitation of mechanical parameters associated with various orthopaedic conditions. The technique of measurement and the interpretation of results is discussed with reference to a model based on elastic rebound.

Biomechanical Phenomena↗
PubMed1976

Design and biomechanical evaluation of a cementable endosteal blade implant.

A cementable endosteal blade implant has been developed and evaluated. Inherent in the design are the following factors: minimization of stress concentrators, ease of implantation, and high resistance to loosening. Other potential advantages of this design as compared with conventional endosteal blade implants include reduced hazards of postoperative infection and reduced likelihood of metallic corrosion. Six conventional endosteal implants and six cementable implants were installed in steer mandibles using standard dental surgical techniques and Simplex-brand methyl methacrylate bone cement. They were loaded in uniaxial compresstion at a loading rate of 0.0122 in./min. the stiffness (S), deformation at 900-lb load (D900), proportional limil (PL), and load at 0.04 in. deformation (L0.04) were calculated for each test. The cementable design showed a twofold increase in stiffness, only 17% of the deformation at 900lb, more than twice the proportional limit, and at least twice the load at 0.04 in. deformation when compared with similar values for the conventional endosteal implants. This study reveals that, in addition to being unstable in bone, conventional endosteal implants are also unstable when used with acrylic bone cement. The new design should eliminate most of the problems associated with endosteal blade implantation.

Animals↗
PubMed1976

An introduction to the biomechanics and biomaterials of bone, joints, and implants.

Biomechanics and biomaterials of bone, joints, and implants has been presented in an overview manner with the use of selected examples. The musculoskeletal system is a living, dynamic entity that is constructed so that changes in mechanics, if the body does not have time to compensate, can lead to major problems over a period of time. The mechanics of the tissues ensure a smoothly operating system.

Biocompatible Materials↗
PubMed1976

Studies of the corrosion susceptibility of metallic cement restrictors: comparative corrosion behavior of stainless steel and cobalt-chromium alloys.

Passive film and accelerated corrosion tests were performed on both wrought AISI 316L stainless steel and wrought Vitallium (Haynes Stellite 25) Charnley Type cement restrictors. The morphology and incidence of corrosion at the wire-wire crevices and the methacrylate-metal crevices were determined by scanning electron microscopy. The results are interpreted in view of the previously-documented crevice corrosion susceptibility of these two alloys.

Bone Cements↗
PubMed1975

Corrosion failure in stainless steel implants.

Two patients in whom corrosion failure of stainless steel implants occurred had the surgically removed implants subjected to metallurgic analysis. Both implants showed marked pitting corrosion and required removal due to adverse tissue reaction. Analysis of the failed implants showed them to be fabricated of alloys with a chemical composition that resulted in inferior corrosion resistance. A simple magnetic test is suggested to indicate this type of stainless steel.

Aged↗
PubMedDate not supplied

Insider/outsider partnerships in an ethnographic study of shared governance.

The benefits of research being undertaken by more than one researcher cannot be underestimated. Having one researcher with intimate knowledge of the organisation and another who could provide a dispassionate view, paid dividends in this study into shared governance from an ethnographic perspective.

Anthropology, Cultural↗
PubMedDate not supplied

Intermediate outcomes by race and ethnicity in peritoneal dialysis patients: results from the 1997 ESRD Core Indicators Project. National ESRD Core Indicators Workgroup.

BACKGROUND: Hispanics are the fastest growing minority group in the United States, and approximately 10% of all end-stage renal disease (ESRD) patients are Hispanic. Few data are available, however, regarding dialysis adequacy and anemia management in Hispanic patients receiving peritoneal dialysis in the U.S. METHODS: Data from the Health Care Financing Administration (HCFA) ESRD Core Indicators Project were used to assess racial and ethnic differences in selected intermediate outcomes for peritoneal dialysis patients. RESULTS: Of the 1219 patients for whom data were available from the 1997 sample, 9% were Hispanic, 24% were non-Hispanic blacks, and 59% were non-Hispanic whites. Hispanics were more likely to have diabetes mellitus as a cause of ESRD compared to blacks or whites, and both Hispanics and blacks were younger than white patients (both p < 0.001). Although whites had higher weekly Kt/V and creatinine clearance values compared to blacks or Hispanics (p < 0.05), blacks had been dialyzing longer (p < 0.01) and were more likely to be anuric compared to the other two groups (p < 0.001). Blacks had significantly lower mean hematocrit values (p < 0.001) and a greater proportion of patients who had a hematocrit level less than 28% (p < 0.05) compared to Hispanics or whites, despite receiving significantly larger weekly mean epoetin alfa doses (p < 0.05) and having significantly higher mean serum ferritin concentrations (p < 0.01). Multivariate logistic regression analysis revealed significant differences by race/ethnicity for experiencing a weekly Kt/V urea < 2.0 and hypertension, but not for other intermediate outcomes examined (weekly creatinine clearance < 60 L/week/1.73 m2, Hct < 30%, and serum albumin < 3.5/3.2 g/dL). CONCLUSION: Hispanics had adequacy values similar to blacks and anemia parameters similar to whites. Additional studies are needed to determine the etiologies of the differences in intermediate outcomes by racial and ethnic groupings in peritoneal dialysis patients.

Adolescent↗
PubMedDate not supplied

A comparison of diabetic foot ulcer patients managed in VHA and non-VHA settings.

OBJECTIVE: To compare patients with diabetes and new onset foot ulcers treated in Veterans Health Administration (VHA) and non-VHA settings. METHODS: The treatment of patients with new onset diabetic foot ulcers was prospectively monitored in three VHA and three non-VHA hospitals and outpatient settings until ulcer healing, amputation, or death. RESULTS: Of the 302 individuals enrolled in this study, 47% were veterans receiving VHA care. There were no significant differences between veterans and nonveterans in baseline wound classification, diabetes severity, or comorbid conditions. Veterans received significantly fewer sharp debridements, total contact casts, and custom inserts than their nonveteran counterparts, and they had significantly more x-rays, local saline irrigations, IV antibiotics, and prescriptions for bed rest. The percentage of amputations was higher in veterans but did not achieve statistical significance. CONCLUSIONS: Many commonly held stereotypes of veteran men were not found. Veterans and nonveterans with foot ulcers were similar in terms of health and foot history, diabetes severity, and comorbid conditions. There was considerable variation in treatment of diabetic foot ulcers between VHA and non-VHA care. Yet this variation did not result in statistically significant differences in ulcer outcomes.

Aged↗
PubMedDate not supplied

Hip cartilage supported by methacrylate in canine arthroplasty.

A theoretically attractive approach to femoral head arthroplasty would be the preservation of a"biologic" bearing surface composed of autogenous articular cartilage and subchondral bone, supported by a prosthetic material with mechanical properties similar to those of trabecular bone. The substitution of such a material for bone would preclude incomplete revascularization of the femoral head and eventual bony collapse. The advantages of preserving the patient's hip joint, even in the face of a fracture that has caused the loss of vascular supply to the femoral head, are self-evident. To test this hypothesis, seven dogs underwent hip arthroplasty, whereby the trabecular bone of the femoral head was replaced with polymethylmethacrylate. When killed 2 1/2 years after operation all of the dogs demonstrated injury or loss of articular cartilage in the superior aspect of the femoral head. The lesions are consistent with advanced osteoarthritis by gross and histologic examination. These lesions apparently were produced by changing either the geometry or stiffness, or both, of the material supporting the articular cartilage. Supporting human articular cartilage with methacrylate for joint arthroplasty is not recommended.

Animals↗