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Biomedical subjects

H Ringertz

Publications and source records attributed to H Ringertz.

At least 37 records · Page 2Linked to original sources
PubMed1995

Bone mineral density in middle-aged women with Turner's syndrome.

Bone mineral density (BMD), bone mineral content and body composition were determined in 47 middle-aged (mean age 47.9 +/- 1.1 years) women with Turner's syndrome. Bone mineral density was measured in the forearm, femoral neck and total body. The women investigated had a BMD lower than the normal mean. When expressed as Z scores (individual values compared to normal reference data matched for age, weight and sex), the median Z score of the total body was -1.23. When comparing women with the karyotype 45,X and mosaic women, the latter showed a higher BMD in all sites of measurement. Duration of hormonal replacement therapy (HRT) differed significantly between the mosaic and the 45,X women, with a longer duration in the mosaic group (20.7 +/- 2 vs 12.1 +/- 2.6 years; p < 0.01). The duration of HRT was found to be the more important factor to maintain bone mass, not the karyotype. Bone mineral density increased with years of HRT but not until after > 20 years of HRT could a significant difference be shown between the women with HRT < or = 20 years and those with HRT > 20 years. No correlation was found between BMD and body weight, body fat or percentage body fat. Whether the osteopenia found in women with Turner's syndrome is similar to that found postmenopausally or is a specific form related to the chromosome aberration remains to be investigated further. The present data support a relation to estrogen deficiency.

Absorptiometry, Photon↗
PubMed1994

Role of MRI in the evaluation of ambiguous genitalia.

Diagnostic accuracy of magnetic resonance imaging (MRI) interpretation was assessed prospectively in patients with ambiguous genitalia or intersex problems. MRI depiction of the uterus was possible in 93%, the vagina in 95%, the penis in 100%, the testis in 88%, and the ovary in 74% of patients. The strength of MRI lies in the multiplanar capability and tissue characterization by means of T1- and T2-weighted sequences. MRI contributes to accurate morphologic evaluation of müllerian duct structures, the gonads, and the development of the phallus, all of which are essential for appropriate gender assignment and planning of surgical reconstruction.

Adolescent↗
PubMed1994

Bone mineral density during long-term prophylaxis with heparin in pregnancy.

OBJECTIVE: We studied the effect of long-term heparin treatment on bone mass during pregnancy. STUDY DESIGN: Thromboprophylaxis with heparin was given to 39 women during pregnancy for a mean of 28 weeks and for an average of 6 weeks post partum. Bone mineral density measured with single-photon absorptiometry of the distal and ultradistal parts of the forearm was determined at the time of the start of heparin treatment (mean, twelfth week of gestation), immediately post partum, and on average 7 weeks post partum. The mean dosage of heparin was 17,300 IU/day. A control group of 34 normal pregnant women was studied for comparison. RESULTS: In women treated with heparin, there was almost a 5% reduction in trabecular bone during pregnancy (p < 0.01) and an insignificant recovery post partum. There were no significant changes in bone mass during pregnancy or in the puerperium in the control group. CONCLUSION: Long-term treatment with heparin during pregnancy is associated with bone loss, but indications of reversible changes are observed.

Adult↗
PubMed1991

Functional restitution after lower leg fractures. A long-term follow-up.

Twenty-five patients with fractures of the lower leg treated by closed reduction and plaster fixation were examined an average of 7 years and 8 months after trauma. The end result was assessed according to the following: (1) The patient's own opinion; (2) clinical examination including comparing range of motion in knee and ankle in the fractured and non-fractured leg, leg length discrepancy, malrotation of the injured extremity and muscle force analysis; (3) radiological examination. All fractures had healed after a mean of 13.4 weeks. Twelve of the 25 patients had no complaints. Subjective and objective assessment of the end results were in good correlation. Only eight patients had remaining radiological displacement, in only one of which it was severe. The slight remaining malpositionings did not influence the final functional result. The muscle force analysis showed that fractures caused by high-energy trauma also brought permanent reduction of muscular strength to the fractured extremity.

Adolescent↗
PubMed1990

Physical and psychological capabilities during substitution therapy with recombinant growth hormone in adults with growth hormone deficiency.

In a double-blind cross-over study with recombinant methionyl growth hormone (GH) and placebo during 12 weeks, the effect of GH substitution therapy (0.5-06 IU.kg-1.week-1) on physical performance, muscle strength, bone mineral density, and mood and cognitive functions was investigated in 6 GH-deficient adults. During GH substitution serum concentrations of insulin-like growth factor-I and procollagen-III peptide increased in all 6 patients, whereas concentrations of serum urea decreased. Five of the patients identified the GH period and reported improved well-being with increased mental alertness and vitality and improved physical capacity and muscle strength. There was, however, no change of the isokinetic muscle strength during GH substitution therapy, and the working capacity on the bicycle ergometer was just slightly improved in some patients. The bone mineral density was low and unchanged in all patients. Mood and cognitive functions did not change during GH therapy. A reversible fluid retention was observed in one patient during the GH period. In conclusion, short-term GH substitution therapy to GH-deficient adults induced a subjective improvement of general well-being. Longer treatment periods will be necessary to establish the effect on physical capacity, muscle strength, bone mineral density, and mood and cognitive functions.

Adult↗
PubMed1990

A computer-based system for measurements and analyses in radiology.

A computer-based system for direct measurements on images and for analyses of data is presented. Distances, angles, and areas are measured on a backlighted digitizer table. Calibration corrects for actual magnification. Data are analyzed and compared to normal values by a microcomputer. The system is precise and time saving.

Child↗
PubMed1988

Barbiturate anaesthesia does not cause pulmonary densities in dogs: a study using computerized axial tomography.

The occurrence of roentgenological densities in dependent lung regions was studied in 28 mongrel dogs (mean weight 18.7 kg) during barbiturate anaesthesia and mechanical ventilation. The densities were analysed by means of computerized tomography, permitting transaxial projections of the thorax. Two dogs showed small densities in dependent lung regions, corresponding to 1% of the total intrathoracic area. In five dogs there were small areas of probably increased density, without sharp delineation, in dependent regions. The remaining 21 dogs (75%) exhibited no densities. The frequency of such densities was thus much lower than has been found in anaesthetized human subjects. Moreover, the densities were relatively smaller than those in man and qualitatively different. It is concluded that the development of dependent lung densities differs both quantitatively and qualitatively between dogs and human subjects.

Absorptiometry, Photon↗
PubMed1987

Sequential scintimetry in prediction of healing rate after femoral neck fracture.

Thirty-one femoral neck fractures which united without complications (nonunion or late segmental collapse) were included in a prospective sequential scintimetric study. Roentgenologically, three subgroups with different healing rates could be distinguished: rapid union, normal union, and delayed union. All fractures showed a rapid increase in relative femoral head radionuclide uptake after the 1-week scintimetry, followed by a gradual decline after 6 weeks-3 months. However, both the initial rise in activity and the time for maximal uptake tended to differ between the three groups. For rapid union and normal union the peak activity was registered at 6 weeks and for delayed union at 3 months. It is concluded that sequential scintimetric assessment of femoral head uptake can identify different healing rates and that this difference can be partly explained by a transient impairment of vascular supply to the femoral head in fractures with delayed healing.

Adult↗
PubMed1987

Sequential scintimetry after femoral neck fracture. Methodologic aspects and prediction of healing complications.

Forty-five patients with recent cervical hip fractures were included in a prospective, clinical, radiographic and sequential scintimetric study. Striking changes in radionuclide uptake over the entire hip region on the fracture side were found during the first 5 postoperative months. Fractures that healed without complications showed the highest relative femoral head uptake at 1 week and a peak value at 6 weeks, followed by a gradual decline at the subsequent examinations. Fractures with complications (redisplacement, nonunion, or late segmental collapse) showed a lower initial uptake and a more gradual increase and only a slight tendency towards increased uptake after 3 months. The accuracy in predicting nonunion with scintimetric examination alone is high both at 1 and at 6 weeks, and the accuracy is almost equally high with combined scintimetric, radiographic, and clinical assessment 3-5 months postoperatively.

Aged↗
PubMed1986

Magnetic resonance imaging in pediatric hematology/oncology. Part I. Basic technology.

Magnetic resonance imaging (MRI) is a promising new diagnostic modality that is well suited for the evaluation of children with hematological or oncological diagnosis. The side effects of ionizing radiation are avoided, the tomographic pathological anatomy in three orthogonal planes can be obtained, and differences between normal and abnormal tissues are often present. In order to present our preliminary clinical experience with MRI in pediatric hematology and oncology, the historical background of MRI, the technique, and possibilities for tissue characterization are reviewed.

Child↗
PubMed1986

Magnetic resonance imaging in pediatric hematology/oncology. Part II. Illustrative cases and assessment of technique.

Preliminary clinical experience with magnetic resonance imaging (MRI) in 28 pediatric patients with 20 different hematological diseases, benign tumors, or malignant neoplasms is presented. The clinical results are presented in the form of case presentations that are discussed in the context of alternative diagnostic imaging modalities. Also discussed are the known biological effects, or lack thereof, the need for sedation, the effect of motion, the effect of MRI on foreign metallic objects, the financial considerations, and the trends for the future of MRI. This imaging modality has many unique merits. Present difficulties should be overcome by future innovations, making MRI even more efficacious for the diagnosis of blood diseases and cancer in children.

Adolescent↗
PubMed1986

[Erroneous diagnosis of nephroblastoma (Wilm's tumor) based on SIOP data].

Available films of 21 cases of erroneously diagnosed Wilms' tumor in the European Wilms' material have been studied. The diagnosis has been reassessed and the reasons for agreement in 6 cases and disagreement in the remaining 15 are discussed. General diagnostic recommendations are given to help secure optimal diagnostic information.

Child, Preschool↗
PubMed1986

Radionuclide scintigraphy of femoral head specimens removed at arthroplasty for failed femoral neck fractures.

In order to determine the value of scintimetry as a tool for quantitative measurement of femoral head vascularity, the results of postoperative scintigraphic and histologic examination of surgically removed femoral head specimens were compared with those of preoperative radionuclide scintigraphy in 19 failed femoral neck fractures. Following intravenous administration of 600 MBq of Tc-99m MDP before hip replacement, the activity distribution in femoral head sections was recorded with a gamma camera and the area of isotope uptake calculated. A correlation was found between the results of preoperative noninvasive radionuclide scintigraphy and the assessment of isotope uptake in the removed femoral head specimens (r = 0.83, p less than .001) and was confirmed by the results of histologic examination. There is a risk, however, of overestimating the ratio of isotope uptake between the femoral head on the fracture side relative to the contralateral side with respect to quantitative assessment of femoral head vascularity, due to the general increase in isotope owing to accumulation in the injured hip region. The calculations, however, reflect the levels of radionuclide uptake and the varying degrees of femoral head vascularity.

Aged↗
PubMed1985

In vivo assessment of left ventricular wall and chamber dynamics during transient myocardial ischemia using cine computed tomography.

Using a new computed tomographic (CT) scanner design that uses a rapidly moving focused electron beam, 50-ms CT scans were obtained at 2 axial levels simultaneously through the hearts of 6 dogs in order to analyze left ventricular (LV) wall thickness and cross-sectional chamber area after acute occlusion of the left anterior descending coronary artery (LAD). Ten or fifteen 50-ms CT scans (rate of 17 scans/s through the middle of the left ventricle were performed in 1 second (cine acquisition) during intravenous administration of contrast medium at rest, 60 seconds after acute occlusion of the LAD, and 60 seconds after release of the occlusion. The percent extent of systolic wall thickening of the potentially ischemic anterior segment was 37 +/- 15% (+/- standard deviation) in the control state and -5 +/- 6.5% during LAD occlusion (p less than 0.01). There was no significant difference in the percent change in LV luminal area from end-diastole to end-systole between the control state (50 +/- 19%) compared with LAD occlusion (47 +/- 21%). There were no significant differences in the extent of systolic wall thickening or LV luminal area between the control state and 60 seconds after release of occlusion. The alterations in regional myocardial function during acute ischemia are characterized by wall thinning during systole in the jeopardized segment and no significant change in global LV function. These features can be assessed by cine computed tomography during a solitary heart cycle.

Animals↗
PubMed1984

Computed tomography in congenital heart disease.

The CT results in defining anatomic and certain physiologic features in patients with congenital heart and great vessel anomalies were reviewed in 32 patients with a variety of congenital cardiac and aortic arch anomalies. Most of these cases (18 patients) were selected on the basis of angiocardiographic or echocardiographic studies performed prior to the CT evaluation. In 14 patients CT was performed as the initial study. All examinations were contrast enhanced and performed on a third generation CT scanner with scan time of 2 or 4 s. The CT demonstration of abnormalities of the great vessels such as positional anomalies, atresias, and hypoplasias was equivalent to angiocardiography and usually superior to two-dimensional echocardiography. The CT results in 14 patients were sufficient to obviate catheterization and angiography; most of these cases were abnormalities of the thoracic aorta. The CT evaluation of intracardiac anatomy was inconsistent. It adequately defined septal defects and configurational (Ebstein anomaly) and bulboventricular loop abnormalities of the ventricles. However, valve anomalies were not adequately demonstrated by CT. The three-dimensional representation of cardiac and mediastinal vascular anatomy provided by this relatively noninvasive technique gives unique information in some cardiovascular anomalies. When faster scanning times are introduced, more definition of the cardiac structures should be possible, further increasing the diagnostic potential of CT.

Adolescent↗