PubMed HealthSearch

Biomedical subjects

J Pugh

Publications and source records attributed to J Pugh.

At least 19 recordsLinked to original sources

Total serum cholesterol levels in Asians living in New York City: results of a self-referred cholesterol screening.

Asians historically have low total cholesterol levels and low incidence of coronary heart disease. In performing a coronary heart disease and total cholesterol screening in New York City's Chinatown, we obtained data supportive of previous studies, which focused on Japanese populations and described the influence of environment on total cholesterol. In the present study, Chinese living in Chinatown have higher levels of total cholesterol than would be expected from studies of Chinese living in Shanghai. For every age group examined, Asian-born Chinese living in Chinatown had higher total cholesterol levels than both urban and rural Chinese in Shanghai. In subjects less than or equal to 30 years of age, urban males in Shanghai had cholesterol levels of 160 +/- 34 mg/dL, compared with 206 +/- 38 mg/dL for Asian-born males in Chinatown. For females in the same age category, cholesterol levels were 162 +/- 35 mg/dL vs 224 +/- 45 mg/dL, respectively. Applying National Cholesterol Education Panel (NCEP) guidelines, the distribution of desirable, borderline-high, and high blood cholesterol levels for the Chinese in Chinatown (41%, 35%, and 23%, respectively) were similar to a group of Caucasians screened (42%, 32%, and 26%) and the group recently used to determine the prevalence of high blood cholesterol in American adults (43%, 30%, and 27%). Studies are needed to stratify the risk of coronary heart disease in other groups that traditionally have a low incidence of coronary heart disease, but which now have adopted Western lifestyles.

Adult

Synthesis of hepadnavirus particles that contain replication-defective duck hepatitis B virus genomes in cultured HuH7 cells.

To evaluate the possibility of producing transducible replication-defective hepadnaviruses, cloned mutant duck hepatitis B virus genomes were tested both for virus antigen production and viral DNA synthesis following transfection into the human hepatoma cell line HuH7. Deletion of a cis-acting 12-nucleotide sequence implicated in viral DNA synthesis, direct repeat 1 (DR1), resulted in the loss of ability to synthesize both mature viral DNA and infectious virus. The delta DR1 mutant, however, produced envelope and core antigens and was shown to provide trans-acting functions required for the assembly of infection-competent particles. Thus, mutants with mutations in viral genes could be rescued as DNA-containing viral particles after cotransfection with delta DR1. The efficiency of rescue was influenced by the site of mutation. A mutant DNA encoding truncated core and envelope proteins not only was poorly rescued but also was able to suppress the production from a wild-type DNA of infectious virus.

Animals

Deterioration of trapeziometacarpal arthritis due to trigger thumb: a biomechanical evaluation.

Patients with trigger thumb and trapeziometacarpal joint arthritis accompanied by swan-neck deformity of their first rays find that their arthritic pain becomes worse whenever their thumbs "catch." Six hands with adduction contracture and arthritis of the trapeziometacarpal joint are studied biomechanically and demonstrate significantly excessive shear forces (p less than 0.01) around their trapeziometacarpal joint relative to six normal hands. Increased pain with deformity suggests aggressive treatment of trigger thumb in cases such as these.

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Cortical pelvic strains with varying size hemiarthroplasty in vitro.

Four human pelves were dissected of soft tissues and instrumented with rosette strain gages. The pelves were left intact (not separated at the pubic symphysis or sacroiliac joints) although each of the eight hemipelves was tested separately. The pelves were loaded to simulate single leg stance with use of a wire mesh cemented to the wing of the ilium, representing the abductor muscles. Loading was carried out with the intact hip joint and 1 mm undersized, correct sized, and 1 mm oversized hemiarthroplasty. The correct sized component produced a strain pattern closet to normal. The oversized component was associated with an increase in strain at the medial acetabular dome.

Acetabulum

Normal pelvic strain pattern in vitro.

Four cadaver pelves were dissected of soft tissue and each of the eight hemipelves instrumented with ten rosette strain gauges. Static loading was conducted to simulate single leg stance, and applied through the intact hip joint. The medial portion of the pelvis was under tension directed vertically and the lateral ilium was in compression. This strain pattern is consistent with bending applied to the ilium from the action of the abductor and joint reaction forces.

Biomechanical Phenomena

Characterization of the major duck hepatitis B virus core particle protein.

The amino acid composition of the major duck hepatitis B virus (DHBV) core particle proteins was determined. The results of this analysis indicated that cores are composed of a single major protein that initiates translation from the second available AUG in the DHBV core gene. Proteins isolated from core particles purified from the cytoplasm of DHBV-infected duck hepatocytes exhibited heterogeneity in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, independent of the stage of viral DNA maturation. Incubation of native cores with alkaline phosphatase removed this heterogeneity, indicating that phosphorylation of external amino acids was responsible. Core protein isolated from mature DHBV purified from serum of infected animals did not display heterogeneity, suggesting a possible role for dephosphorylation in virus maturation.

Alkaline Phosphatase

Nebuhaler or nebulizer for high dose bronchodilator therapy in chronic bronchitis: a comparison.

We have compared the clinical efficacy of high dose terbutaline sulphate (10 mg four times daily) delivered by either a Nebuhaler or jet nebulizer in 13 patients with chronic bronchitis in a 2-week, open, crossover study. Both treatment regimens improved run-in symptom scores but no significant changes were recorded in peak flow and spirometry. Side-effects were more common with the Nebuhaler and more patients preferred the nebulizer. However, the Nebuhaler is an alternative therapeutic option for delivery of high doses of bronchodilators in patients with chronic bronchitis.

Aged

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

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

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

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

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.

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