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Biomedical subjects

L V Avioli

Publications and source records attributed to L V Avioli.

At least 253 records · Page 14Linked to original sources
PubMed1979

Adult hypophosphatasia. Clinical, laboratory, and genetic investigation of a large kindred with review of the literature.

Investigation of the kindred of a 58-year-old woman with all of the features of "adult" hypophosphatasia revealed 12 individuals in 3 generations with subnormal circulating total alkaline phosphatase (AP) activity. The pattern of inheritance suggested autosomal dominant transmission, with incomplete penetrance of the trait particularly in the young males. Hypophosphatasic individuals other than the proposita were clinically well but had loss of permanent teeth, showing that dental abnormalities could be the only clinical manifestation of the disorder. Radiographic investigation of the proposita revealed that completion of stress fractures was necessary for healing; maturation of incomplete fractures resulted in stable Looser zones. Skeletal survey and radionuclide bone imaging were unremarkable in hypophosphatasic individuals without fracture. Subclinical osteopenia was found in several affected women by metacarpal cortical width and bone densitometric measurements. Laboratory studies showed increased plasma and urinary phosphoethanolamine levels in affected individuals. Phosphoethanolamine and phosphoserine appeared to be natural subtrates for AP since a negative correlation existed between each substrate and circulating total AP activity. Phosphoethanolamine and phosphoserine levels were greatest in the clinically affected proposita; furthermore, only she showed absence of leukocyte AP activity. Heat fractionation of her total circulating AP activity suggested severe reduction in the bone isoenzyme. Hypophosphatasic children had higher levels of total circulating AP than affected adults; the increase was apparently secondary to increased bone isoenzyme. Iliac crest bone biopsies showed greater abnormality in affected women. Osteoidosis was particularly pronounced in the proposita's younger affected sister and hypophosphatasic daughter. Histomorphometric analyses of the biopsies revealed a paucity of osteoblasts despite increased quantities of unmineralized matrix. The finding that hypophosphatasic children in this kindred had higher circulating total AP activity than adults and were able to model their skeleton normally, together with observations that the bone biopsy in adults had a paucity of osteoblasts, suggests that some factor(s) during growth is able to induce both AP activity and osteoblast function, or, that this disorder is an "abiotrophy" with deficient osteoblastic formation and/or accelerated destruction in adult life.

Adolescent↗
PubMed1979

Idiopathic hypothalamic hypogonadotropic hypogonadism with polyostotic fibrous dysplasia.

A 22-year-old woman had polyostotic fibrous dysplasia (POFD) and idiopathic hypothalamic hypogonadotropic hypogonadism (isolated gonadotropin deficiency). Recurrent fracture of dysplastic bone during childhood was associated with primary amenorrhea, clinical and laboratory evidence of estrogen deficiency, and subnormal circulating and urinary gonadotropin levels during adolescence. Gonadorelin (luteinizing hormone-releasing hormone) stimulation initially showed a luteinizing hormone (LH) response but absent follicle-stimulating hormone (FSH) response. After three months without estrogen and progesterone and after four days of gonadorelin "priming," a subsequent gonadorelin infusion produced an enhanced LH and FSH response. All other tests of peripheral and trophic hormone levels and pituitary trophic hormone reserves were normal. Whereas POFD is known to occur with sexual precocity and other endocrinopathies, to our knowledge this is the first report of its association with isolated gonadotropin deficiency.

Adult↗
PubMed1979

The relationship of biochemical and histometric determinants of uremic bone.

Simultaneous histometric and biochemical analyses were performed on 16 bone biopsy specimens taken from eight patients with chronic renal failure. The bone calcium and phosphorus contents are inversely related to the relative volume of microscopically measured, nonmineralized bone matrix (osteoid) and to the percentage of trabecular surface covered by this tissue. The magnesium content of uremic bone is positively correlated with the quantity of osteoid. Skeletal calcium and phosphorus contents correlate inversely with the osteoblast population, and phosphorus relates directly to the volume of trabecular bone. Bone hydroxyproline content does not correlate significantly with any histometric variable. As one may now infer biochemical conclusions about the uremic skeleton from morphological observations, these data may facilitate interpretation of nondecalcified histological sections of bone.

Bone and Bones↗
PubMed1978

Effect of testosterone therapy on bone formation in an osteoporotic hypogonadal male.

Osteoporosis has been reported to complicate androgen deficiency in males. Accordingly, we have evaluated an osteoporotic hypogonadal male with bone histomorphometry before and after 6 months of testosterone replacement. Androgen therapy resulted in increases in relative osteoid volum, total osteoid surface, linear extent of bone formation, and bone mineralization. The dramatic histological response to hormonal replacement confirms the importance of androgens in bone modeling and remodeling.

Adult↗
PubMed1978

Idiopathic multicentric osteolysis. Report of an affected father and son.

Genetic, rheumatologic, immunologic, metabolic, and renal studies of a father and son with idiopathic multicentric osteolysis are reported. The disorder appeared through mutation. The father developed symptoms as an infant, his son at age 4 years and 9 months. Both have micrognathia and hypotelorism and were exceptionally tall during the symptomatic phase of their disease. Biopsies of the son's wrist showed normal synovium, encroachment on cartilage by fibrocellular tissue, and both osteoclastic resorption and repair of affected bone. Hydroxyproline in his urine was increased. No immunologic, renal, or other metabolic abnormalities were identified.

Adult↗
PubMed1978

Childhood renal osteodystrophy.

The processes of growth and remodeling that characterize growing bone are vulnerable to the biochemical effects of uremia. These processes are affected by the alterations in vitamin D metabolism and hyperparathyroidism that commonly occur with chronic renal insufficiency. Uremia interferes with cartilaginous developments as well. These changes, which are similar radiographically to vitamin-D-deficiency rickets, differ in their basic histological and biochemical evolution. They account for growth failure and deformity of long bones, which contribute to the short stature of children with renal insufficiency.

Bone Development↗
PubMed1978

Lithium inhibition of bone mineralization and osteoid formation.

Lithium chloride administration to growing rats, which resulted in circulating lithium levels of 1.4 meq/liter, was attended by significant suppression of bone mineralization and organic matrix synthesis as assessed by tetracycline labeling and histological quantitation of osteoid, respectively. These effects of lithium were not associated with changes in animal behavior, nor were there any significant differences in blood levels of calcium, phosphorus, alkaline phosphatase, creatinine, pH, or parathyroid hormone. The data suggest that lithium inhibition of bone mineralization is secondary to suppression of osteoid formation.

Animals↗
PubMed1978

Effect of oral glucose ingestion on renal phosphate reabsorption and clearance in vitamin D-resistant rickets.

The effect or oral glucose ingestion on renal phosphate reabsorption was studied in 13 patients with the inherited form of vitamin D-resistant rickets (VDRR) and 5 normal subjects. In contrast to the normal subjects, glycosuria developed in six VDRR patients after glucose ingestion and resulted in a further 43% decrease in renal phosphate reabsorption. This was accompanied by a 33% increase in phosphate clearance. This was not attended by differences in fasting glucose or phosphorus levels between groups, or in their respective values 1 h after glucose ingestion. Baseline renal phosphate reabsorption was less and baseline phosphate clearance was greater in those VDRR subjects who developed glycosuria. The accumulated data suggest that excessive glucose ingestion by some patients with VDRR may add an additional insult to the phosphaturia characteristic of this disorder. This, in turn, would further compromise the response of circulating phosphate to therapeutic attempts at oral phosphate supplementation, thereby reducing the efficacy of oral phosphate therapy on skeletal growth and development in this disorder.

Adolescent↗
PubMed1978

Assessment of acute and chronic changes in parathyroid hormone secretion by a radioimmunoassay with predominant specificity for the carboxy-terminal region of the molecule.

A sensitive RIA for parathyroid hormone (PTH) with specificity for the carboxy-terminal region of the hormone was developed and applied to clinical studies. The assay was useful in identifying patients with chronic hyperparathyroid states, such as primary and secondary hyperparathyroidism. In addition, the assay could detect acute changes in PTH seen during calcium, pentagastrin, and EDTA infusions and after parathyroidectomy. These studies demonstrated that an immunoassay with predominant specificity for the carboxy-terminal fragment of PTH can be used to evaluate acute as well as chronic changes in hormone secretion.

Calcitonin↗
PubMed1978

Inflammatory bowel disease (ulcerative colitis).

There is uncertainty as to the proper management of a patient with chronic ulcerative colitis who has had his disease for over ten years but has not been sufficiently symptomatic to warrant colectomy. Not all patients are at high risk to develop cancer. Wide extent and long duration of disease are correlated with increased risk. The ability to define a patient at risk beyond these single criteria are very limited. The definition and efficacy of the precancerous lesion observed in rectal biopsies is still a matter of dispute, and the routine use of proctocolectomy for patients with long-standing colitis is still not universally accepted. Careful follow-up is obviously indicated, but it is still uncertain whether roentgenography, colonoscopy, colonic biopsy, or a combination of these methods will ultimately prove the procedure of choice.

Adult↗
PubMed1978

Antacid-induced osteomalacia and nephrolithiasis.

A 36-year-old woman suffered from bone pain, muscle weakness, and renal stones after prolonged ingestion of antacids for esophageal reflux. Investigation disclosed hypophosphatemia, hypercalciuria, and osteomalacia by bone biopsy. All symptoms and abnormal laboratory findings reversed with a regimen of oral phosphate supplementation and cessation of antacid intake.

Adult↗