Search PubMed⌕ Search

Biomedical subjects

R L Cruess

Publications and source records attributed to R L Cruess.

At least 19 recordsLinked to original sources
PubMed1988

Principles and results of corrective lower limb osteotomies for patients with vitamin D-resistant hypophosphatemic rickets.

Forty-four lower limb osteotomies were performed in ten patients with vitamin D-resistant hypophosphatemic rickets. The average follow-up period was 51 months. Osteotomies were combined with shortening and compression plating. This allowed corrections of angular deformities in the sagittal plane as large as 70 degrees and in the coronal plane as large as 78 degrees. There was one complication, a compartment syndrome that resolved completely following prompt fasciotomy. Recurrence of deformity occurred in 27% of the cases. While osteotomies were safe and provided dramatic improvement to limb deformity, postoperative control of vitamin D metabolism was the one constant factor for maintenance of correction.

Adolescent↗
PubMed1987

Temporal relationship between fetal bovine skeletal growth and circulating hormonal levels.

Skeletal growth and serum hormonal levels in bovine fetuses were studied cross-sectionally from late first trimester to late third trimester of gestation (corresponding approximately to 75-275 days of age, and a crown-rump (CR) 5-105 cm/in size). Measurements of tibial and femoral lengths showed that bone growth proceeds at a 30% faster rate in fetuses of 50-105 cm CR, coincident with the appearance and exponential growth (y = 0.000207 e 0.12522 x; y, dried weights of ossification in grams and x, CR in cm) of a secondary center of ossification in the epiphysis. During this period there is an increase in the proportion of [3H]-thymidine-labeled nuclei (measured by autoradiography) in the proliferative zone of the epiphyseal growth plate and a progressive hypertrophy of chondrocytes in the epiphysis; in serum there is a rise in alkaline phosphatase activity, a rise in the calcium, and a decrease in the phosphorus concentrations. Cellularity (nuclei/area) and the proportion of [3H]-thymidine labeled nuclei in epiphyseal cartilage decline during the period of 15-105 cm CR, except at 25-45 cm CR when both parameters of chondrocyte growth have transiently stabilized. [35S]-Sulfate and [3H]-proline incorporation (cpm/100 micrograms DNA) in epiphyseal cartilage also decline initially during 10-25 cm CR, then attain a stable level during 25-50 cm CR; subsequently, [35S]-sulfate incorporation gradually increases and [3H]-proline incorporation remains at a constant level. The proportion of [3H]-thymidine-labeled nuclei in the epiphyseal growth plate also declines in early gestation, then becomes stabilized at 20-50 cm CR. The whole growth plate thickness varies during gestation and is maximal during 20-50 cm CR. The proliferative zone attains maximal thickness at 20-50 cm CR while the hypertrophied and degenerative zone has maximal thickness at 40-80 cm CR. Gestational changes of hormone levels were quantitated in fetal serum. Glucocorticoids and thyroxine were measured by radioimmunoassay; somatomedinlike bioactivity was measured as the capacity of a serum sample to stimulate [3H]-thymidine incorporation in chondrocytes compared to that of a control serum. Temporally related to the changes occurring in the skeletal tissues, there is a high serum level of glucocorticoids at 10-20 cm CR when the cartilaginous activities are declining, a peak level of serum somatomedinlike bioactivity at 20-50 cm CR when cartilage growth and metabolism become stabilized, and a rise of thyroxine level after 45 cm CR during which time there is an increasing rate of bone formation.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1987

Gestational changes of thyroid hormone action in the developing fetal bovine epiphysis.

Thyroid hormones are essential for cartilage growth and maturation. In order to assess their actions during different periods of skeletal development, [125I]-triiodothyronine (T3) binding capacity in epiphyseal cartilage and triiodothyronine concentrations in serum were quantitated in bovine fetuses of the second and third trimesters of gestation (equivalent to fetal sizes of 10-90 cm crown-rump (CR) length), and related to the alkaline phosphatase activities in the same cartilaginous tissues. Nuclear T3 binding levels, which were initially low during 10-30 cm CR, rose to a peak value (1.7 pmol/mg DNA) at the end of the second trimester (40-50 cm CR). Then, following a sharp decline at 50-60 cm CR, T3 binding rose to a moderate level in the later gestational period (60-90 cm CR). Serum total triiodothyronine rose transiently in fetuses of 30-50 cm CR to a peak level (34 ng/100 ml), and subsequently increased continuously in the later period (60-90 cm CR). Alkaline phosphatase activities measured in epiphyseal chondrocytes rose significantly in fetuses of 60-90 cm CR. The coincident rise of cartilage triiodothyronine binding capacity and serum circulating triiodothyronine levels in the late second trimester suggests that this thyroid hormone induces its own binding sites in bovine epiphyseal cartilage; the dramatic increase in the level of serum triiodothyronine during the third trimester of gestation is temporally related to the increase in alkaline phosphatase activity of chondrocytes, as well as other recognized developmental changes in the fetal bovine skeletal tissues.

Alkaline Phosphatase↗
PubMed1986

Gestational changes in the level of glucocorticoid-binding sites in fetal bovine cartilaginous tissues.

In order to assess glucocorticoid actions on fetal cartilage development, [3H]dexamethasone binding site levels in fetal bovine cartilaginous tissues from long bones were measured, using a whole cell assay at 37 degrees C. Displaceable [3H]dexamethasone binding in epiphysial growth cartilage was maximal (16.2 fmol/10(6) cells) in fetuses of 10-15 cm crown-rump length (CR), and declined to 22% of the maximum in fetuses of 20-30 cm CR. Subsequently, [3H]dexamethasone binding rose to a plateau (13.0 fmol/10(6) cells) in fetuses of 30-80 cm CR and declined in those of 80-100 cm CR. When measured in growth plate cartilage, [3H]dexamethasone binding was significantly higher in fetuses of 40-80 cm CR (39 fmol/10(6) cells) than in those of 80-100 cm CR. There was no significant change of [3H]dexamethasone binding affinities in epiphysial chondrocytes of 5-100 cm CR fetuses or in growth plate chondrocytes of 40-100 cm CR fetuses. These results demonstrate that fetal cartilaginous tissues during development possess varying cellular levels of glucocorticoid binding and may thus have temporal changes in sensitivity to glucocorticoid hormones.

Animals↗
PubMed1986

Osteonecrosis of bone. Current concepts as to etiology and pathogenesis.

Experimental and some clinical evidence suggest that one or more mechanisms, alone or in combination, induce bone necrosis. These include marrow cell hypertrophy, microembolic phenomena, and lipid-induced osteocyte necrosis. Such events may result in local inflammatory exudates and/or vascular impedence. Either may effect an increase in the hydrostatic pressures in bone with the potential to limit blood flow and magnify the initial insult. Further experimental investigations are necessary to gain knowledge of etiologic mechanisms and a rational means of prophylaxis or treatment.

Animals↗
PubMed1985

Steindler lecture. Binding sites in fetal and growth plate cartilage.

In addition to genetic and nutritional factors, linear growth during the prenatal and postnatal periods is controlled by peptide, steroid, and thyroid hormones interacting with the receptors present on the membrane or in the cytosol and nuclei of growth plate cartilage. Using standard procedures, insulin and "nonsuppressible insulin-like activity" (a somatomedin) showed significant binding in 600, 15,000, and 105,000 g membrane fractions of epiphyseal cartilage of immature animals. The binding of growth hormone and prolactin was small and probably not significant. Specific uptake of glucocorticoid was demonstrated in viable canine chondrocytes, but not of androgen, estrogen, or vitamin D3 metabolite. A triiodothyronine receptor was present in nuclei from dog epiphyseal cartilage. Hormones that lack binding may affect cartilage only indirectly. Hormone receptors were studied in those portions of fetal growth cartilage that will later evolve into an ossification center, articular cartilage, and epiphyseal cartilage. Cytosol fractions contained a receptor for glucocorticoid but not for androgen or estrogen. Zonal analysis showed a higher level in the peripheral and central sections than in the palisade section. Triiodothyronine binding was also detected in nuclei prepared from whole fetal cartilage. Heterogeneity of cell function was obvious in fetal cartilage. Cell division was high in the central and peripheral zones as well as the upper half of the palisade zone, but low in the lower palisade section. Proline and sulfate incorporation predominated in the palisade section compared with the central and peripheral sections. Disease states with changes of metabolic activities in the cartilage may perhaps be better understood with a clearer knowledge of receptor levels and interactions.

Animals↗
PubMed1985

Corticosteroid-induced osteonecrosis of the humeral head.

Cortisone-induced osteonecrosis of the shoulder occurs in a fashion that is roughly similar to that seen in the hip. It appears that the cortisone itself is responsible for the lesion, and patients who develop the condition can have a minimal lesion that heals well, a moderate deformity that is well tolerated, or severe joint disease requiring surgical correction. A knowledge of the natural history of the condition allows for rational and generally successful therapy.

Adrenal Cortex Hormones↗
PubMed1984

The response of articular cartilage to weight-bearing against metal. A study of hemiarthroplasty of the hip in the dog.

Hemiarthroplasty of the hip and some other joints has been used for many years with satisfactory results, but the fate of articular cartilage when weight-bearing against metal has not been reported. Replacement of the head of the femur was carried out in one hip of each of 26 dogs, and the changes in acetabular cartilage studied at intervals of up to 24 weeks. There was early loss of proteoglycan, followed by surface damage to the cartilage, progressive degenerative changes, and growth of pannus from the articular margins. At 24 weeks after operation there was little remaining articular cartilage, while intense subchondral activity suggested that the bony skeleton was being remodelled to conform to the shape of the prosthesis. This study is not intended to suggest that hemiarthroplasty does not help patients.

Acetabulum↗
PubMed1984

Hormone receptors in the epiphysial cartilage.

In order to assess which hormones may exert direct effects on skeletal growth at the epiphysial growth plate, the specific binding of hormones to the epiphysial cartilage of growing dogs and rabbits was studied. Membrane fractions obtained by centrifugation of homogenates prepared from dog and rabbit growth plate cartilage at 600, 15 000 and 105 000 g showed significant specific binding of serum insulin-like activity and insulin. Binding of growth hormone and prolactin by the three membrane fractions was negligible. Saturable binding sites for triiodothyronine could be demonstrated in nuclei from the dog growth plate. Nuclear binding showed an apparent Kd of 11 +/- 3.6 nmol/l and a maximum binding capacity of 4.1 +/- 1.6 pmol/mg DNA, a level comparable to dog liver. Using a viable chondrocyte suspension prepared from dog epiphysial cartilage, specific steroid binding in the cells could be demonstrated for [3H]dexamethasone but not 17 alpha-methyltrienolone, oestradiol-17 beta or 1 alpha, 25-dihydroxycholecalciferol. Scatchard analysis of dexamethasone binding showed high affinity binding sites having a Kd of 1.2 +/- 0.35 nmol/l and a capacity of 1700 sites/cell, and a low affinity binding with a Kd of 109 +/- 57 nmol/l and a capacity of 24 000 sites/cell. Steroid competition for the specific binding showed the following sequence of affinity: dexamethasone greater than corticosterone greater than 11-deoxycortisol greater than testosterone greater than oestradiol-17 beta.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

Zonal analysis of cytoplasmic steroid hormone receptor levels: replication and synthetic activity in embryonic calf growth cartilage.

Using the dextran charcoal method, a specific steroid receptor for dexamethasone, but not 17 beta-estradiol or 17 alpha-methyltrienolone, was demonstrated in cytosol prepared from mid-gestation fetal calf growth cartilage. Zonal analysis of cytoplasmic receptor levels showed that tissue sections from the center, the peripheral surface, and the palisade section bound 229 +/- 111, 173 +/- 64, and 15 +/- 28 femtomole dexamethasone per mg of protein, respectively. Incorporation of 3H-thymidine, 35S-sulfate, and 3H-proline into cartilaginous tissues was used as an index of replication and synthetic activity. The percentage of 3H-thymidine labeled nuclei, as determined by radioautography, showed that the palisade zone has a significantly lower replicating activity (P less than 0.001). Values were 5.6 +/- 1.2, 5.4 +/- 1.2, 3.8 +/- 1.3, and 1.1 +/- 0.2 for the center, peripheral surface, and upper and lower half of the palisade section. The rate of sulfate and proline incorporation into the palisade zone was over seven times higher than the central and peripheral surface (P less than 0.001). The difference in the rate of matrix synthesis and proliferating activity in these regions may be related to the zonal heterogeneity of receptor levels of glucocorticoids in fetal growth cartilage.

Animals↗
PubMed1982

Pigmented villonodular synovitis of joints.

In a series of 38 young adults with intra-articular pigmented villonodular synovitis, the joint predominantly affected was the knee. For early diagnosis of intra-articular pigmented villonodular synovitis, a high level of suspicion is necessary for patients with complaints of persistent pain or swelling in the knee, or erosive osteoarthritis of the hip and shoulder of unknown etiology in young individuals. Arthrography of the knee was not found to be a very helpful test in the diagnosis of pigmented villonodular synovitis. Localized intra-articular pigmented villonodular synovitis should be treated by local excision. Diffuse intra-articular pigmented villonodular synovitis of the knee should be treated by extensive synovectomy followed by manipulation under general anesthesia two to three weeks postsurgery. Intra-articular pigmented villonodular synovitis of the shoulder and hip should be treated by extensive synovectomy or by total joint arthroplasty in cases with marked bone destruction and cyst formation.

Adolescent↗
PubMed1982

A retrospective study of Moore and Thompson hemiarthroplasty. A review of 599 surgical cases and an analysis of the technical complications.

In a retrospective review of 580 patients with 599 hemiarthroplasties of the hip, 454 operations (75.8%) were carried out as primary procedures for fresh intracapsular fractures, and 145 operations (24.2%) were performed as salvage procedures. The three-month mortality rate was 5.0%, and the dislocation rate was 5.3%. The early results were assessed by roentgenograms alone; head size, neck length, stem-shaft angle, and calcar seating were measured on preoperative and postoperative films. Anteversion and retroversion could not be accurately assessed. Using an arbitrary rating system, the results were graded as excellent on the basis of four anatomical criteria: good, on the basis of three; fair, of two; and poor, on only one or none. Only 173 prostheses (26.3%) were graded as excellent and 103 (27.3%) as good. At least 70 (25.3%) were just fair, and 31 (11.2%) were poor. Inappropriate neck length was present in 55.0% of the dislocated prostheses, incorrect head size in 25.0%, varus of the prosthesis in 20.0%, and poor calcar seating in 25.0%. Thus, technical errors account for a significant number of imperfect hemiarthroplasties of the hip. Careful attention to detail should decrease the incidence of errors and improve end-results.

Adult↗