PubMed Health⌕ Search

Biomedical subjects

R A Adams

Publications and source records attributed to R A Adams.

At least 37 records · Page 2Linked to original sources
PubMed1992

Comparative skeletogenesis of the forearm of the little brown bat (Myotis lucifugus) and the Norway rat (Rattus norvegicus).

This study describes, quantifies, and compares the growth and development of the volant forelimb morphology of Myotis lucifugus with that of the terrestrial forelimb morphology of Rattus norvegicus. In M. lucifugus there is 1) accelerated growth in forearm length after parturition, 2) cessation in growth of the midshaft diameter of the ulna just after the onset of osteogenesis, 3) proximal fusion of the radius and ulna, which results in the radius occupying 97% of the articular surface of the elbow joint in adults, 4) fusion between the cartilaginous distal epiphyses of the radius and ulna which results in formation of a radioulnar bridge that becomes fully ossified in adults, and 5) incomplete ossification of the ulna with a section of the diaphysis becoming ligamentous. None of these events occurs during development in R.norvegicus.

Animals↗
PubMed1992

Semiconstrained arthroplasty for the treatment of rheumatoid arthritis of the elbow.

Fifty-four patients in whom a total of fifty-eight semiconstrained modified Coonrad elbow implants had been inserted for rheumatoid arthritis were followed for a mean of 3.8 years (range, two to eight years). At the latest follow-up, there was little or no pain in fifty-three elbows (91 per cent). The arc of motion was from an average point in flexion of 20 degrees to an average point in flexion of 129 degrees, representing an average increase of 12 degrees of extension and 11 degrees of flexion. The average arc of pronation was 78 degrees, an increase of 14 degrees, and the average arc of supination was 77 degrees, an increase of 18 degrees. An additional ten patients who had had insertion of ten modified Coonrad implants during the same period were followed for less than two years but were included in the assessment of complications. Fifteen (22 per cent) of the sixty-eight elbows had a complication: four, infection; eight, acute or delayed condylar or ulnar fracture; and one each, ulnar neuritis, avulsion of the triceps, and fracture of the implant. Radiographic evaluation was performed for fifty-four of the fifty-eight elbows; the other four were excluded from this evaluation because of infection. A satisfactory radiographic appearance of the cement--its extent and the absence of skip areas--was noted for all of the ulnar components and for fifty-one (94 per cent) of the humeral components. No patient had radiographic evidence of a loose implant. A reoperation was performed in six elbows (10 per cent of the fifty-eight; 9 per cent of the sixty-eight): four were done for infection; one, for insufficiency of the triceps; and one, for a fractured ulnar component. Of the fifty-eight elbows, forty (69 per cent) had an excellent result; thirteen (22 per cent), a good result; four (7 per cent), a fair result; and one, a poor result.

Arthritis, Rheumatoid↗
PubMed1991

Total replacement for post-traumatic arthritis of the elbow.

Fifty-three of 55 consecutive elbow replacements for post-traumatic arthritis were followed for a minimum of two years (mean 6.3, range 2 to 14.4). The patients presented difficult management problems, having undergone an average of two previous operations per joint; 22 joints had suffered prior complications; 18 had less than 50 degrees of flexion and six were flail. One of three versions of the Coonrad prosthesis was employed in all. During the follow-up period, 10 patients underwent 14 revision procedures for aseptic loosening; 38 elbows are currently without progressive radiolucent lines. In two patients an elbow had to be resected, one for deep infection and the other for bone resorption following a foreign-body reaction to titanium. The current design of the Coonrad prosthesis offers a reliable option for the treatment of post-traumatic arthritis but should be used only in carefully selected patients over the age of 60 years.

Adult↗
PubMed1991

Strengthening hospital nursing. An approach to restructuring care delivery.

The authors present an institution-wide approach to restructuring nursing practice. Unit action committees, restorative care paths, permanent care teams, and a physician/nurse liaison committee were four major strategies implemented. Nursing's major goals from this project were to increase autonomy, enhance collaborative practice, and reward with salary commensurate with management responsibility.

Delivery of Health Care↗
PubMed1990

Late recurrence of varus deformity after proximal tibial osteotomy.

One hundred thirteen knees with medial gonarthrosis in 95 patients were treated by valgus-producing proximal tibial osteotomy and followed clinically and roentgenographically for a minimum of five years (mean, 6.3 years). Sixty-four knees (57%) were pain free or had only mild discomfort when walking. The standing femorotibial angle decreased from a postoperative average of 9.3 degrees valgus to 7.8 degrees valgus at the final follow-up examination. The tendency for varus recurrence greater than 5 degrees and for medial- or lateral-compartment arthritic progression was evaluated using the Kaplan-Meier survival method. Varus recurred in 18%, lateral-compartment arthritic progression in 60%, and medial-compartment arthritic progression in 83% by nine years after surgery. The probability of arthritic progression is much higher than the probability of significant varus recurrence in long-term roentgenographic follow-up studies of patients with valgus-producing proximal tibial osteotomies.

Adult↗
PubMed1988

Structural and immunological characterization of the myosin-like 110-kD subunit of the intestinal microvillar 110K-calmodulin complex: evidence for discrete myosin head and calmodulin-binding domains.

The actin bundle within each microvillus of the intestinal brush border is tethered laterally to the membrane by spirally arranged bridges. These bridges are thought to be composed of a protein complex consisting of a 110-kD subunit and multiple molecules of bound calmodulin (CM). Recent studies indicate that this complex, termed 110K-CM, is myosin-like with respect to its actin binding and ATPase properties. In this study, possible structural similarity between the 110-kD subunit and myosin was examined using two sets of mAbs; one was generated against Acanthamoeba myosin II and the other against the 110-kD subunit of avian 110K-CM. The myosin II mAbs had been shown previously to be cross-reactive with skeletal muscle myosin, with the epitope(s) localized to the 50-kD tryptic fragment of the subfragment-1 (S1) domain. The 110K mAbs (CX 1-5) reacted with the 110-kD subunit as well as with the heavy chain of skeletal but not with that of smooth or brush border myosin. All five of these 110K mAbs reacted with the 25-kD, NH2-terminal tryptic fragment of chicken skeletal S1, which contains the ATP-binding site of myosin. Similar tryptic digestion of 110K-CM revealed that these five mAbs all reacted with a 36-kD fragment of 110K (as well as larger 90- and 54-kD fragments) which by photoaffinity labeling was shown to contain the ATP-binding site(s) of the 110K subunit. CM binding to these same tryptic digests of 110K-CM revealed that only the 90-kD fragment retained both ATP- and CM-binding domains. CM binding was observed to several tryptic fragments of 60, 40, 29, and 18 kD, none of which contain the myosin head epitopes. These results suggest structural similarity between the 110K and myosin S1, including those domains involved in ATP- and actin binding, and provide additional evidence that 110K-CM is a myosin. These studies also support the results of Coluccio and Bretscher (1988. J. Cell Biol. 106:367-373) that the calmodulin-binding site(s) and the myosin head region of the 110-kD subunit lie in discrete functional domains of the molecule.

Acanthamoeba↗
PubMed1987

Complications and mortality associated with bilateral or unilateral total knee arthroplasty.

The incidence of complications, the need for secondary surgical procedures, and the mortality rate associated with bilateral replacement of the knee performed simultaneously, performed during the same hospitalization, or performed during separate hospitalizations were compared with those after unilateral replacement of the knee. The incidence of complications after 290 simultaneous bilateral procedures was 9.3 per cent, which compares favorably both with the incidence of 7.0 per cent after 228 bilateral procedures that were done during the same hospitalization and incidence of the 12.0 per cent after 234 bilateral procedures that were performed during separate hospitalizations. The incidence for each of these groups compares favorably with the incidence of complications of 11.0 per cent after 501 unilateral procedures. The incidence of reoperation was 2.4, 4.8, 8.5, and 5.6 per cent, respectively, in the four groups, and the incidence of mortality was 5.5, 0.9, 3.8, and 7.0 per cent. None of these differences were statistically significant. These data indicate that the incidence of morbidity and mortality that is associated with simultaneous bilateral total knee arthroplasty is no greater than when the procedure is performed during the same hospitalization or separate hospitalizations.

Costs and Cost Analysis↗
PubMed1987

Unusually aggressive transmission of tuberculosis in a factory.

A case of pulmonary tuberculosis in a factory worker was studied to identify infected contacts and to gauge the degree of transmission. Initial findings suggested far more extensive transmission than anticipated, and the study was expanded. Of all factory workers tested, 33% were infected with the tubercule bacillus in spite of massive air volume-to-contact ratio. Deliberate stagnation of the air to prevent occupational exposure to lead and asbestos was believed to be a contributing variable.

Adult↗
PubMed1986

A Periodontitis Severity Index.

A Periodontitis Severity Index (PSI) was developed and then tested in a population of 154 patients attending the University of Mississippi School of Dentistry screening clinic. Patients were grouped by age decade. The premises of the PSI follow: (1) Periodontitis is diagnosed on the concurrence of clinically apparent marginal inflammation and vertical loss of supporting periodontium (the severity of the associated clinical inflammation does not seem to be related to the severity of the tissue loss) and (2) a Schei ruler is used to determine from the radiograph the percentage of bone loss for a tooth surface. For each patient, a 0 to 1 Clinical Inflammation Score (CIS) was determined at the mesial and distal of every tooth. A CIS of 0 reflected no demonstrable clinical inflammation, whereas a CIS of 1 meant that clinical inflammation could be detected. A modified Schei ruler was used to determine the percentage of bone loss at each interproximal site. A Bone Loss Score (BLS) was calculated on a 0 to 10 whole number continuum. A BLS of 0 meant no bone loss, 1 = up to 10%, etc., up to BLS 10 = 90 to 100% loss. The PSI was then calculated for each mesial and distal surface. PSI = BLS X CIS. The PSI could be 0 if either no bone loss could be determined or the gingiva was healthy. In the presence of marginal inflammation, the PSI value was directly proportional to the percentage of bone loss. Mean PSI values were calculated for each age group. The PSI tended to increase with age. The PSI offers several advantages.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Base-line data in a carcinogen-susceptible first-generation hybrid strain of Syrian golden hamsters: F1D Alexander.

Base-line data in over 600 control animals of both sexes of the first-generation hybrid BIO F1D Alexander strain of Syrian golden hamsters are presented. They involve mortality, body weights, spontaneous tumor incidence, and incidence of nonneoplastic lesions. The results confirmed previously published data on smaller numbers of animals of this hamster strain. Spontaneous tumors with an incidence of more than 2% were limited to lymphomas (less than or equal to 6%), adrenocortical carcinomas (less than 8%), adrenal adenomas (9-14% in males; 3.5% in females), islet cell adenomas (less than 6%), and follicular adenomas of the thyroid gland (3.5% in females only). This low incidence of spontaneous tumors and the high survival rate (compared to those of hamsters from other sources), together with the previously established high susceptibility to tumor induction by carcinogen administration, render the F1D Alexander hamster an excellent animal model for lifetime carcinogenesis bioassays.

Amyloidosis↗
PubMed1985

Significance of 801 monoclonal proteins detected during 7 years of screening in a district general hospital.

This study describes the biochemical follow-up of 801 patients in whom a monoclonal protein had been detected, by screening protein electrophoresis, during a 7-year period. A further blood sample was obtained from 61% of the group and information was available on an additional 32%. Follow-up times ranged from 2 months to almost 8 years. The level of monoclonal protein was measured and any increase related to the level at detection, presence of reduced polyclonal immunoglobulins (RPI), and Bence Jones Protein (BJP). Seventeen (2.1%) monoclonal proteins had disappeared and 428 (88%) demonstrated no significant change in level. Only 26 (3.2%) patients showed a significant increase. This suggests that the majority of monoclonal proteins detected on screening electrophoresis are benign. The presence of BJP is still considered to be the most significant biochemical prognostic criterion. In contrast, finding RPI seems to be least useful. A monoclonal protein level greater than 19 g/l is usually associated with an immunocyte related disease as is an increase in the level of more than 6 g/l. Therefore, assessment of the benign or malignant nature of monoclonal proteins using biochemical prognostic criteria at detection alone is not sufficient. It is recommended that the minimum follow-up should involve review at 3 months and then at yearly intervals.

Aged↗
PubMed1984

Comparison of heterotopic bone after anterolateral, transtrochanteric, and posterior approaches for total hip arthroplasty.

The effects of anterolateral, transtrochanteric, and posterior surgical approaches for total hip arthroplasty on heterotopic bone formation were studied in 507 consecutive patients with osteoarthritis or avascular necrosis who had not had previous hip surgery. Range of motion, degree of pain, and satisfaction were compared. Although the lowest incidence of ectopic ossification occurred after the posterior approach, there were no statistically significant differences among the three approaches. Extensive ectopic bone, involving more than half the distance between the trochanter and acetabulum, occurred in 29% after anterolateral, 28% after lateral transtrochanteric, and 22% after posterior approaches. Motion was most affected by the lateral approach, whereas relief of pain and general satisfaction were slightly better with the posterior approach. Multivariate statistical analysis suggests that the difference in results (p less than 0.05) with the posterior approach is primarily due to a relatively lower incidence of severe grades of heterotopic bone.

Adult↗
PubMed1984

The incidence of monoclonal proteins during 7 years of screening in a District General Hospital.

The aim of this study was to assess the incidence of monoclonal proteins, during a 7-year period, in the population served by a typical District General Hospital. 183,300 sera were electrophoresed and 804 monoclonal proteins were detected. Various biochemical prognostic criteria, such as the concentration of monoclonal protein, incidence of Bence-Jones protein and the presence of reduced polyclonal immunoglobulins, were studied in an attempt to assess the benign or malignant nature of the monoclonal protein. In this study, 75% of the patients with monoclonal proteins fulfilled at least one of these criteria, demonstrating the importance of long-term monitoring.

Adolescent↗
PubMed1983

Osseous repair in the presence of active tooth hypermobility.

The present investigation was undertaken to evaluate the periodontal response after resolution of inflammation in a situation of established marginal periodontitis, but in the presence of active, continued tooth hypermobility. Periodontitis was induced unilaterally around mandibular second and third bicuspids in 4 squirrel monkeys by tying plaque retentive silk ligatures at the gingival margins. Jiggling trauma to the periodontium between these bicuspids was begun 5 weeks later and continued for the remaining 20 weeks. Ligatures were removed 15 weeks after placement, whereupon regular oral hygiene was begun and continued. Periodontitis and trauma were produced around the corresponding contralateral teeth (control) so that the interproximal area represented the situation immediately prior to ligature removal. Infiltrated connective tissue, loss of connective tissue attachment and alveolar bone, and percentage of bone were determined histometrically for each coronal interproximal periodontium. In control specimens, 58% of the supracrestal tissue was infiltrated with inflammatory cells compared to 19% in experimental specimens. There were no differences in levels of connective tissue attachment or crestal alveolar bone. However, bone repair occurred in the experimental specimens which increased bone volume from 11 to 18% (P less than 0.05). It was concluded that osseous repair occurred in the presence of active, continued tooth hypermobility after resolution of inflammation.

Alveolar Process↗
PubMed1982

Detection of gamma glutamyl transpeptidase in the livers of germfree and conventional rats.

Germfree and conventional rats, 1-41 months of age, were examined for gamma glutamyl transpeptidase in frozen sections prepared from their livers. This histochemical marker has been associated with early changes which develop following exposure to known carcinogenic agents. Positive gamma glutamyl transpeptidase markers were detected in 86% of germfree rats over 4 months of age, and the gamma glutamyl transpeptidase foci were larger and more numerous as the animals aged, and the foci were prominent in rats with hepatic tumors. Gamma glutamyl transpeptidase foci were observed in 96% of livers from conventional rats at 11-20 months of age. The agents responsible for induction of the gamma glutamyl transpeptidase foci in the liver were not identified.

Aging↗
PubMed1981

Interproximal and buccal cell populations apical to the sulcus before and during experimental periodontitis in squirrel monkeys.

The purpose of this investigation was to study inflammatory cell populations apical to the buccal and interproximal gingival sulcus during destructive experimental marginal periodontitis in squirrel monkeys. Specimens were obtained of the clinically healthy periodontium, and (after 2 and 10 weeks) of experimental periodontitis induced by the placement of plaque-retentive silk ligatures at the gingival margin. Cell populations were characterized and quantitated in a standard area of connective tissue immediately subjacent to the most apical cells of the junctional epithelium in buccal and interproximal locations. Comparisons of periodontitis cell populations showed there were no differences between the regions in relation to either total numbers of cells, or in the percentages of inflammatory cell types. The inflammatory cells consisted primarily of granulocytes and macrophages, with only small percentages of lymphoid and plasma cells. Mechanisms and consequences of these cell types relative to periodontal tissue destruction are discussed.

Animals↗