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Biomedical subjects

I Zanzi

Publications and source records attributed to I Zanzi.

At least 55 records · Page 3Linked to original sources
PubMed1977

Combination therapy for osteoporosis.

The effect of therapy that simultaneously stimulates bone formation and inhibits bone resporption was evaluated in five patients with primary osteoporosis. The technique of in vivo neutron activation analysis was used to measure total body calcium (TB-Ca). The patients were treated with calcium supplements and salmon calcitonin combined with either a low or a high dose of growth hormond (hGH). There was no significant increase in skeletal mass (TB-Ca) during the low-dose hGH regimen. An increase in skeletal mass was observed in all patients following the high-dose regimen, except for one patient who developed secondary hyperparathyroidism. Although this study must be considered to be of a preliminary nature, the magnitude of the response in calcium balance suggests that skeletal mass can be increased in osteoporosis if combination therapy is employed.

Absorption↗
PubMed1977

Body elemental composition: comparison between black and white adults.

The age-related changes in body chemical composition were measured in a normal black population ranging in age from 30 to 80 yr. The levels of total-body calcium, phosphorus, sodium, and chlorine were measured by in vivo neutron activation. In addition, the lean body mass (total-body potassium) was measured by whole-body counting of 40K. These data were compared with the same data obtained on a normal white population in a previous study. Although there were no significant differences in the height of the two groups, black men and women had significantly higher total-body calcium, phosphorus, sodium, chlorine, and potassium than the sex-and age-matched white population. The increased levels of total-body calcium and potassium when normalized for the weight and height of the subjects were reduced but still remained significantly higher than those of the white population. Clearly specific reference standards for skeletal and muscle mass as well as for sodium and chlorine need to be established for black populations.

Adult↗
PubMed1977

Radiographic morphometry and osteopenia in spinal osteoporosis.

Measurements of bone mineral content and total-body calcium, normalized and expressed as ratios, were compared with radiographic morphometry in 45 women who had spinal osteoporosis. The radiographic indices examined included the femoral score, the femoral trabecular pattern, the biconcavity and metacarpal indices, and the total peripheral score. Both ratios and all the radiographic indices except the femoral trabecular pattern were found to be related to the number of dorsal spine fractures. The relationships observed support the following conclusions: (A) the femoral score and the metacarpal index are related to the degree of osteopenia; (B) the biconcavity index reflects the extraskeletal factors that are pathogenic in spinal osteoporosis; (C) a reduced femoral trabecular pattern index is associated with spinal osteoporosis, although this measurement is not related to the degree of osteopenia; and (D) it may be imprudent to diagnose osteoporosis from the presence of lumbar compression fractures.

Age Factors↗
PubMed1976

Total body sodium and chlorine in normal adults.

Absolute levels of total body sodium (TBNa) and total body chlorine (TBCl) were determined in 81 normal adults (39 males, 42 females) by means of total body neutron activation analysis (TBNAA). The ages of the subjects ranged from 30 to 90 yr. The mean values for both TBNa and TBCl remained relatively constant throughout the age span studied for males, but decreased slightly for females over 60 yr of age. In order for the absolute measurements of Na and Cl to be of clinical value, the values must be compared to a predicted value based on the sex and body habitus of the individual. Normalization of TBNa values relative to body dimensions (weight, height, body surface area) were evaluated. In addition, TBNa was related to total body calcium (TBCa), which reflects skeletal mass, and TBK, which reflects muscle, or lean body mass. Normalization in terms of a linear combination of the TBCa and TBK was found to be the most satisfactory of all those studied. Sodium excess, NaES, defined as the amount of body sodium (mEq) in excess of body chlorine (mEq) was determined. Sodium excess correlated well with total body calcium. Values for total body sodium and chlorine obtained in the present study were compared with values previously reported in the literature.

Adult↗
PubMed1976

Changes in body chemical composition with age measured by total-body neutron activation.

Total-body levels of calcium and phosphorus (reflecting skeletal mass) and total-body levels of potassium (reflecting muscle mass) were measured by neutron activation analysis in 39 men and 40 women ages 30-90 yr. In order to intercompare the total body calcium (TBCa) values in a heterogeneous population, such as this, it was necessary to normalize the data for skeletal size. The normalization consisted of dividing the absolute calcium level by the predicted calcium level for each individual matched to a set of critical parameters. The parameter used in the computation of normal values were age, sex, muscle mass, i.e., total body potassium (TBK) and height. For the calcium data of the women, it was necessary to add an age correction factor after the age of 55 yr. The calcium ratio(mean ratio of the predicted to measured TBCa) in men was 1.000 +/- 7.8% and in women 0.996 +/- 7.1%. The TBCa of normal males and females can thus be predicted to +/- 13% (at the 90% confidence level). An exception to this was found in males (70-90 yr) who exhibited a mean calcium ratio greater than 1.13. The derivative of TBCa with time was determined for this population of men and women by taking into account the dependency of calcium on three time dependent variables, height, TBK, and an explicit age correction factor in the case of the women. The mean rate of loss of TBCa in women was 0.37% and 1.1% per year before and after menopause (50 yr). In the males, the average rate of loss of TBCa was 0.7% per year after 50 yr of age. The pattern of total body phosphorus (TBP) loss with age paralleled that of TBCa as the ratio of TBP/TBCa was rather constant with age. The constancy of the ratio suggests that the mineral composition of bone does not change significantly with age. The rate of loss of TBK with age was also related directly to that of TBCa. The mean ratio of TBK/TBCa was 9.9 in females and 8.0 in males and this ratio remained relatively constant from 30-70 yr. Thus, the mechanism responsible for the loss of bone with age, whether nutritional deficiency or decreased gonadal function and physical activity may also be responsible for the loss of muscle mass with age.

Adult↗
PubMed1976

Effect of aging on bone mass in adult women.

Total-body calcium was measured in 40 adult women by total-body neutron activation analysis (TBNAA). Procedures for normalizing the absolute calcium measurements for the parameters of size and age were developed in order to effect a direct comparison of women of age 30-78 yr. The normal total-body calcium (TBCa) for an individual can be predicted by a formula developed in the present study to within +/- 11% (1.62 SD) at the 90% confidence level. The TBCa loss can be characterized by two components: one with a slower rate, 0.37%/yr, and the other with a faster rate, 1.08%/yr. The latter, a more rapid postmenopausal loss, started at 50-60 yr and was superimposed on the slower rate of loss that started in the fourth decade and continued throughout life. The bone mineral content (BMC) of the radius, measured by the absorptiometric technique, correlated well with the total-body skeletal calcium in this population (r = 0.813, P less than .001). However, for intercomparisons of the BMC values of individuals, normalization of the BMC values for size and age is required, as it is for the TBCa data. Normalization provided by the ratio of BMC to radius width is not adequate for comparative studies.

Adult↗
PubMed1976

Effects of growth hormone in osteoporosis.

The effect of chronic administration of growth hormone (GH) to osteoporotic patients was studied using the techniques of total body neutron activation analysis, whole body counting, calcium tracer kinetics, photon absorptiometry, quantitative microradiography, and urinary hydroxyproline. Two dosage schedules were utilized for six months each: 2 units daily and 0.2 w3/4 units of GH daily (where W represents body weight expressed in kg). The lower dosage (2 units) did not produce any appreciable change in the indices studied. Following the higher dose, no evidence of any anabolic effect was apparent in most patients (i.e., no increase in total body levels of Ca, Na, K, P, or Cl). Increases were noted in the urinary calcium excretion rate and in the urinary hydroxyproline excretion. Bone mineral content decreased. The bone biopsies displayed an increase in bone formation and resorption surfaces in response to treatment, but these changes were not statistically significant. It may be concluded that under the conditions of this study, GH administration did not result in an increment in skeletal mass. Several side effects that are characteristic of acromegaly were observed, including hyperglycemia, hypertension, arthralgia, and the carpal tunnel syndrome. Because of the lack of demonstrated benefit and the associated complications of therapy, GH administration does not appear to be of value in the treatment of osteoporosis.

Bone and Bones↗
PubMed1975

Absence of an effect of chronic administration of growth hormone on serum lipids.

Human growth hormone (hGH) was administered to a group of osteoporotic patients at two dosage levels for a period of 6 mo each. The first dose employed was 2 units subcutaneously daily, and the second dose was 0.2W-3/4 units (where W is body weight expressed in kg) daily. There was no significant change in serum-cholesterol or triglyceride concentration despite the production of hyperglycemia and soft-tissue swelling on the higher dosage regimen. A number of factors may account for the conflict between our findings and a previous report in which hGH administration had a lypocholesterolemic, hyperglyceridemic effect. These factors include differences in sex, age, dosage, and duration of treatment. Nonetheless, it is clear that from a therapeutic vantage, even if hGH were readily available, it would not be a useful hypocholesterolemic agent.

Aged↗
PubMed1975

Phonton absorptiometry and skeletal mass in the treatment of osteoporosis.

Thirty-six osteoporotic patients who underwent several therapeutic regimes were studied on two occasions by photon absorptiometry and total-body neutron activation analysis (TBNAA). These determinations were made at a mean interval of 8.9 plus or minus 0.8 months. The 8-cm radial site was chosen for the photon absorptiometry which was performed with the Norland-Instruments Densitometer. Mean initial bone mineral content (BMC) was 0.724 plus or minus 0.069 gm/cm and mean bone width was 1.235 plus or minus 0.072 cm. The mean percent change in BMC (%deltaBMC) was 1.02 plus or minus 4.2. The initial total-body calcium (TBCa) as determined by TBNAA was reduced when compared with values that would be expected from empirically derived formulas. The mean percent change in TB-Ca (%deltaTB-Ca) was -3.2 plus or minus 4.7. Most patients displayed a change in BMC and TB-Ca that was at least 2 s.d. greater than the precision of the methods used (%deltaTB-Ca greater than 2). No relationship was found between the deltaBMC and the deltaTB-Ca (r = 0.17). These findings suggest that changes in the radical BMC at the 8-cm site cannot be extrapolated to indicate changes in skeletal mass in response to treatment of osteoporosis. Whether photon absorptiometry at other sites or at multiple sites provides a closer relationship to changes in skeletal mass (TB-Ba) remains to be determined.

Activation Analysis↗