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D Uebelhart

Publications and source records attributed to D Uebelhart.

43 records · Page 3Linked to original sources
PubMed1990

Urinary excretion of pyridinium crosslinks: a new marker of bone resorption in metabolic bone disease.

The pyridinium derivatives hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP) are intermolecular crosslinking compounds of collagen which are only present in its mature form. Contrasting to the wide distribution of type I and II collagens, HP and LP are absent from skin, ligament and fascia, and their major sources are bone and cartilage. Using a specific HPLC assay, we have determined the 24-h excretion of HP and LP crosslinks in normal adults of both sexes, in patients with primary hyperparathyroidism and in patients with Paget's disease of bone before and after intravenous treatment with amino-propylidene bisphosphonate (APB). Mean adult normal values were 33 +/- 13 pmol/mumol creatinine for HP and 6.3 +/- 3.4 pmol/mumol creatinine for LP. In women, menopause induced a 2-3-fold increase of HP and LP reflecting the well documented postmenopausal increase of bone turnover. In the urine of patients with primary hyperparathyroidism and of patients with active Paget's disease of bone, urinary crosslinks were significantly higher than in age-matched controls, with a mean 3- and 12-fold increase, respectively. Urinary excretion of hydroxyproline is a well recognized but poorly sensitive marker of bone turnover, reflecting resorption. In the same patients, the effect of menopause and disease state on hydroxyproline excretion was much less dramatic than on HP and LP. During intravenous APB treatment of pagetic patients, there was an early decrease of HP and LP, which was significant after 24 h and reached 62% at 4 days, contrasting with a late and milder decrease of urinary hydroxyproline. Because APB is a potent inhibitor of resorption which does not have a direct short-term effect on bone formation, these data also indicate that urinary excretion of HP and LP reflect only collagen degradation occurring during osteoclastic resorption and not the degradation of newly synthesized collagen. We conclude that urinary HP and LP excretion represents the first sensitive and specific marker of bone resorption. Its use should be valuable in the clinical investigation of metabolic bone diseases, especially osteoporosis.

Adult↗
PubMed1989

Synovial fluid hydroxyapatite crystals: detection thresholds of two methods.

A method of synovial fluid preparation giving optimal hydroxyapatite detection as well as definitions of the threshold masses of hydroxyapatite in viscous synovial fluid detectable by x ray diffraction and scanning electron microscopy with energy dispersive analysis is reported. Use of an equal volume of 100% hydrazine with the synovial fluid optimised detection of hydroxyapatite. By x ray diffraction the threshold mass of hydroxyapatite was 500 micrograms and by scanning electron microscopy with associated energy dispersive analysis 5 micrograms.

Centrifugation↗
PubMed1989

Bone metabolism in hemiplegic patients.

Bone metabolism has been assessed in 36 hemiplegic patients (18-77 years), 26 with CVA and 10 with head injuries. The results show an increase of serum calcium and phosphorous levels in the first month as well as hydroxyprolinuria. The radiological examination showed signs of demineralisation, as well as single photon absorptiometry of both arms. Bone scan by 99Te demonstrated a hypercaptation in both paralysed limbs. From the 36 patients, 17 had a 47Ca kinetic study which showed an average of normal values as far as bone accretion (Vo+) is concerned. However, the two youngest patients (18 and 32 years) had a high value of this parameter. The urinary calcium excretion (Vu) and the fecal calcium excretion (Vf) was also increased in the 17 patients. The bone resorption measured by Vo- was also high at the beginning of the study and significantly decreased 12 months later. Our observations show that neurologic osteoporosis of the hemiplegic patient is related to an unbalance between the synthesis and the degradation of a bone whose metabolism is active. Related to the determination of the intramedullary pressure and intraosseous phlebography, it seems that this resorption is due to a venous stasis. This circulatory modification regime can influence cell differentiation and probably be responsible in a way for this osteoporosis.

Adolescent↗
PubMed1986

[Presence of newberyite in the right kidney and carbonated apatite in the left kidney in a patient with recurrent urinary infections].

In about 20% of the cases, urolithiasis is directly linked to chronic urinary tract infection by urea splitting bacteria, essentially Proteus mirabilis. The stones are generally composed of struvite and carbonate apatite which usually occur as staghorn calculi feared because of their obstructive and infectious consequences that cause important renal damage. The case of a 48 year-old woman with chronic urinary infection is described whose right kidney showed a staghorn calculus essentially composed of newberyite, a very rare constituent of urolithiasis, and whose left kidney contained three carbonate apatite calculi. Clinical and technical examinations, relations between the two mineral constituents are discussed in this paper with a review of the literature on the subject.

Apatites↗
PubMed1984

[Coralliform calculi and recurrent urinary infection: a case of newberyite calculi (MgHPO4.3H2O)].

In some 20% of cases urolithiasis is directly linked to chronic urinary tract infection by urea-splitting bacteria and essentially Proteus mirabilis. The stones are generally composed of struvite and carbonate apatite, which usually occur as the staghorn calculi feared because of their obstructive and infectious consequences which cause important renal damage. A case is described of newberyite calculus in a woman with chronic urinary infection. Newberyite is thought to be a breakdown product of struvite in particular physico-chemical conditions, and is a very rare constituent of urolithiasis. X-ray diffraction and infrared spectroscopy were used to identify the constituent. Clinical and technical investigations are briefly described, and the literature is reviewed.

Female↗
PubMedDate not supplied

Symptoms of recurrent intrathecal baclofen withdrawal resulting from drug delivery failure: a case report.

A 24-yr-old, completely (T8) paraplegic male patient presenting with severe spasticity had a drug administration device implanted in April 1991 for continuous intrathecal administration of baclofen. After a period of remarkable improvement in both the spasticity level and his quality of life, the patient experienced several short-lasting episodes of increased spasticity, with severe spasms. Among the possible causes of these deleterious episodes were microcrystalluria, obstipation, a decubitus ulcer, a foreign body in the buttocks, drug tolerance to baclofen, electromagnetic interference, and erroneous filling and programing of the pump. The catheter was the most common source of intrathecal baclofen withdrawal symptoms and had to be changed four times in 5 yr. Intrathecal baclofen administered through an implantable drug administration device is a highly effective but complex and expensive procedure that requires careful patient selection and close monitoring by highly qualified and well-trained health professional. Withdrawal symptoms may be related to noncompliance on the part of the patient, erroneous filling or programing of the pump, depletion of the battery, random component failure, concomitant illness, drug tolerance, or advancement of the disease itself. When failure of the device is suspected, substitution with oral baclofen is recommended until a full work-up is performed to determine the defect.

Adult↗