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Biomedical subjects

H Genant

Publications and source records attributed to H Genant.

34 records · Page 2Linked to original sources

Case report 718. Osteopetrosis with carbonic anhydrase II deficiency.

This case report describes the clinical and radiographic findings in an adult woman with osteopetrosis with carbonic anhydrase II deficiency. This uncommon entity is the only one of the five variants of osteopetrosis with a well-defined inborn error of metabolism. The radiographic combination of osteopetrosis and cerebral calcification should suggest the diagnosis, which can be confirmed with a blood sample demonstrating carbonic anhydrase II deficiency.

Adult↗

Enhanced precision with dual-energy X-ray absorptiometry.

Repeat spine and femur measurements (5 per case) were done on 19 subjects with the DPX-L densitometer operating at 3 mA giving a radiation flux fourfold higher than the earlier DPX model. The precision for spine bone mineral density (BMD) was about 0.55% (L2-L4) and 0.48% (L1-L4) for 2-minute scans (2.4 mrem). The precision was only slightly lower (0.4-0.5%) for 4-minute scans (5 mrem) in a subset of 11 subjects. There was a slight precision advantage for the larger L1-L4 area compared with L2-L4 for 2-minute scans, but no advantage for 4-minute scans. The precision for femoral neck BMD was 1.00 and 0.85% for 2- and 4-minute scans, respectively, with proper positioning. The corresponding values for the Ward's triangle region of the femur were 2.6 and 1.5%. The precision of spine scans was influenced chiefly by variable region location. The precision of femur scans was affected by both patient positioning and location of the region. The 4-minute scans minimized the number of operator changes necessary for analysis. Precision errors can be reduced by up to 50% with utilization of the higher flux, but this does not obviate the need for care in patient positioning and scan analysis.

Absorptiometry, Photon↗

[Possibilities of MR tomography of diseases of the hand and wrist].

MRI studies of 63 patients with various abnormalities of the hand and wrist were analyzed. Studies were performed on scanners with a field strength of 0.35, 0.5, or 1.5 T. Imaging parameters included T1- and T2-weighted sequences in the coronal and transverse planes and contiguous slices 3-5 mm thick. In 37 patients with post-traumatic disorders, MRI revealed carpal avascular necrosis, tendon abnormalities and, in some cases, abnormalities of interosseous ligaments and the triangular fibrocartilage. In 15 patients with such inflammatory diseases as arthritis, tenosynovitis and carpal tunnel syndrome and in 11 patients with tumors, MRI provided clear delineation of osseous and soft tissue abnormalities. The current role of MRI in the diagnosis of hand and wrist abnormalities is discussed on the basis of these results.

Adolescent↗

Radiographic assessment of progression in osteoarthritis.

We evaluated methods of grading radiologic progression of osteoarthritis (OA). Sets of radiographs were assessed separately by 8 readers who were blinded to the time sequence. Included were radiographs of patients with OA of the hands (24 pairs), hips (40 pairs), and knees (32 pairs). Most films were taken 12-60 months apart. The relative contribution of individual joints (such as particular interphalangeal joints), of observations (such as narrowing or spurs), and of a single joint compartment (such as the medial or lateral compartment of the knee) toward evidence of OA progression was evaluated, as well as the reliability and concordance of scoring, and the sensitivity in detecting change. In assessing OA of the hand, the greatest sensitivity was achieved by reading a single posteroanterior bilateral hand radiograph for narrowing, spurs, and erosions, and scoring 10 joints (second and third distal interphalangeal, second and third proximal interphalangeal, and trapeziometacarpal joints, bilaterally), using a scale of 0-3. In OA of the hip, a single anteroposterior radiograph assessed for joint space narrowing and cyst formation yielded the greatest sensitivity. In OA of the knee, an anteroposterior radiograph, with weight-bearing, assessed for narrowing, spurs, and sclerosis in both the medial and lateral compartments yielded the greatest sensitivity. These techniques will be useful to the investigator in designing experimental studies and to the clinician in determining the rate of disease progression in an individual patient.

Aged↗

Assessment of radiologic progression in rheumatoid arthritis. A randomized, controlled trial.

Radiologic assessment of progressive joint destruction in rheumatoid arthritis is generally considered to be the ultimate standard for evaluation of treatment. We compared alternative radiologic techniques by performing a randomized, controlled trial in which hand films of rheumatoid arthritis patients were read by several skilled observes. The number of joints evaluated (34 versus 18) was found to make relatively little difference, but the number of readers and their experience level was critical. Films should be read in pairs. Joint space narrowing and erosion scores were shown to contribute independent information. Use of recommended techniques can reduce the number of patients required and, thus, can reduce the cost of a clinical trial by more than half and can substantially increase the sensitivity and efficiency of a trial. Therefore, critical selection of the method of assessing study endpoint is of great importance.

Arthritis, Rheumatoid↗

Stereophotogrammetry of the lumbar spine. A technique for the detection of pseudarthrosis.

A computer-assisted photogrammetric method for the detection of pseudarthrosis following spinal fusion is described. This radiologic method is quantitative and noninvasive and requires a minimum of clinician time. Results of tests with a phantom specimen are presented. Preliminary indications are that the method may prove to be a useful adjunct to the clinician in monitoring the postoperative course of patients requiring fusion procedures.

Lumbar Vertebrae↗

Menstrual function and bone mass in elite women distance runners. Endocrine and metabolic features.

Bone mass and metabolic features were studied in 17 women distance runners. Eleven of the women had secondary amenorrhea for 1 to 7 years. Six women have maintained regular menses since menarche. Both groups were matched for aerobic capacity, body fat, exercise intensity, and age of menarche. Mineral density of lumbar spine in the amenorrheic runners was lower than that in the cyclic women and age-matched controls, but higher than that in runners with secondary amenorrhea who are less physically active. Mineral density of the radius was normal in both groups. Running-related fractures were more frequent in amenorrheic women. Metabolic assessment showed no differences between groups, except that serum triiodothyronine was lower in the amenorrheic group, perhaps reflecting low calorie intake. Intense exercise may reduce the impact of amenorrhea on bone mass; however, amenorrheic runners remain at high risk for exercise-related fractures.

Adolescent↗

Parathyroid and bone response of the diabetic patient to uremia.

Biochemical and radiologic indices of bone disease were assessed in 26 insulin-dependent diabetic patients and 28 nondiabetic patients with endstage kidney disease. The two groups were comparable in age, sex, duration of renal failure, and length of time on dialysis. Diabetic patients showed significantly lower serum calcium and immunoreactive parathyroid hormone (iPTH) levels than nondiabetic patients. iPTH was not related to total serum calcium, but was positively correlated with serum phosphorous (r = 0.37, P less than 0.05 and r = 0.54, P less than 0.005, in nondiabetic and diabetic patients, respectively). iPTH correlated with alkaline phosphatase (r = 0.59, P less than 0.0009) and calcitonin (r = 0.51, P less than 0.05) only in nondiabetic patients. Osteitis fibrosa was noted radiologically in 30% of nondiabetic patients and in none of the diabetic patients (P less than 0.03). Bone morphology in eight diabetic patients who underwent iliac bone biopsy was characterized by reduced trabecular and osteoid bone volume, no woven bone, and marked reduction in indices of bone formation and resorption. The small amount of bone and lack of osteomalacia are a unique feature of the diabetic patient with chronic renal disease. The long-term sequelae of low bone turnover and reduced circulating iPTH may present a special problem to the long term diabetic survivor on the current therapies of uremia.

Adult↗

Effects of naproxen on connective tissue changes in the adjuvant arthritic rat.

The Freund's adjuvant-injected rat shares a number of features with the arthritis patient, viz the presence of a proliferative synovitis, joint swelling, and cartilage and bone erosion. Naproxen, a prostaglandin synthetase inhibitor which is an effective antiinflammatory agent in laboratory animals and humans, was evaluated as an inhibitor of connective tissue destruction in this model by use of radiologic and histopathologic analyses. Sixteen days after rats were injected with Freund's complete adjuvant, marked joint swelling was noted. On day 17, vehicle or naproxen, 7 mg/kg/day, was administered orally. Twenty-eight days later vehicle-treated animals demonstrated the following pathologic changes in their hindpaws; swelling, cartilage loss, large amounts of pannus within the joint spaces, osteoporosis, bone erosions, periosteal new bone formation, heterotopic ossification, and bony ankylosis. Rats treated 28 days with naproxen had significantly milder disease than the vehicle controls. The incidence of severe juxtaarticular bone destruction was 10/10 in the vehicle controls versus 2/10 of the drug-treated group (P less than 0.01). A comparable reduction in cartilage erosion, incidence of pannus, and new bone formation was noted in the drug-treated group. These effects may relate to an inhibition of prostaglandin biosynthesis; prostaglandins have been shown to: 1) stimulate collagenase secretion from macrophages, 2) stimulate bone resorption in vivo and in vitro, and 3) diminish proteoglycan synthesis in cartilage.

Animals↗

The reflex sympathetic dystrophy syndrome. I. Clinical and histologic studies: evidence for bilaterality, response to corticosteroids and articular involvement.

Eleven consecutive patients fulfulling criteria for the reflex sympathetic dystrophy syndrome (RSDS) were studied by quantitative clinical methods, providing measurements of swelling (ring size), tenderness (dolorimeter) and functional capacity (grip strength). The predominantly affected extremity was clearly identified by these technics and its serial progress determined in six patients. Corticosteroid therapy predictably resulted in improvement of all treated patients. Greater tenderness was found in the joints than in the interjoint areas, indicating a possible accentuation of the disease process in juxta-articular tissues. Synovial biopsy specimens in four patients were abnormal, and the histology was presented in detail for the first time. All patients showed bilateral involvement during the study, providing evidence for a central neural mechanism in the RSDS.

Adult↗

Shoulder MRI: the subacromial/subdeltoid bursa fat stripe in healthy and pathologic conditions.

The MRI appearance of the subacromial/subdeltoid (SA-SD) bursa is described here in both healthy and pathological conditions. Based on one case of rotator cuff tear and intrabursal fluid outlined by two adjacent fat stripes we reviewed 20 shoulder MR examinations to define the normal and abnormal appearance of the peribursal fat. We found four pathological patterns: lateral displacement, tear-drop configuration, obliteration and double fat stripe.

Adipose Tissue↗