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Biomedical subjects

M Kaye

Publications and source records attributed to M Kaye.

36 records · Page 2Linked to original sources
PubMed1978

Changes in red cell space of bone in hypocalcemic states: studies in rat femur.

With the use of technetium-99m-labeled red cells, the red cell space of the femur was found to be increased in rats fed a 0.01 percent Ca diet for 4 wk, at which time they were also hypocalcemic. Rats fed the same diet for 2 wk did not demonstrate hypocalcemia nor hypervascularity of the femur. Thyroparathyroidectomized (TPTX) rats fed the calcium-deficient diet produced hypocalcemia nor hypervascularity as did TPTX rats fed a normal diet for 4 wk. However, bone vascularity was normal at 2 wk post-TPTX (normal diet) when the degree of hypocalcemia was less marked. Inhibition of prostaglandin synthetase with oral indomethacin 0.2 mg/100 g per 12 h for 60 h did not alter the red cell space estimates but did increase bone blood flow in both normal and calcium-deficient animals. Acute restoration of normocalcemia with CaCl2 orally in the calcium-deficient rats did not revert the bone hypervascularity. The evidence suggests that in these models of hypocalcemic states, the rise in the vascular space of bone does not result from the influence of PTH, calcitonin, diet, or prostaglandins.

Animals↗
PubMed1978

Complications in expanded polytetrafluoroethylene arteriovenous grafts: an angiographic study.

Expanded polytetrafluoroethylene grafts were used for creation of arteriovenous shunts in 35 patients on chronic hemodialysis. When flow studies or mechanical factors indicated abnormal flow in the graft, angiography was performed. Detection of venous backflow or obstruction, arterial stenosis, aneurysm formation, or graft kinking facilitated correction and thus salvage of the grafts.

Aneurysm↗
PubMed1978

Natural fluorescence in serum of patients with chronic renal failure not to be confused with creatine kinase-BB isoenzyme.

We assessed the reported presence of creatine kinase-BB isoenzyme in the serum of patients with chronic renal failure. Our study showed that the blood of these patients contains a fluorescent material with an electrophoretic mobility similar to that of the BB isoenzyme on cellulose acetate strips. The fluorescing material is, however, completely distinct from BB isoenzyme and its nature is as yet undetermined.

Creatine Kinase↗
PubMed1978

Polytetrafluorethylene (PTFE) grafts for hemodialysis. 18 months' experience.

18 months clinical experience with 6 mm polytetrafluorethylene forearm grafts for hemodialysis access has been described. 35 grafts were implanted, all in patients who had unsuitable vessels for construction of a regular Brescia-Cimino forearm fistula. The overall patency was 71% with mean duration of 10.3 months, and at any one time more than 85% of the grafts at risk were functional. Complications, including undesirable flow rates, edema, thrombosis, aneurysm and cardiac failure have been discussed and rational methods of avoidance described. We believe the polytetrafluorethylene (PTFE) graft represents an important advance in hemodialysis access.

Adult↗
PubMed1978

Hemodynamic studies in patients with expanded polytetrafluoroethylene (PTFE) forearm grafts.

21 patients with polytetrafluoroethylene grafts inserted for hemodialysis access were studied to assess the hemodynamic parameters. Mean graft flow was 1.9 l/min with a range of 0.2-3.8 l/min. Intragraft pressure varied from 1 to 83 mmHg and was dependent on systemic pressure, graft flow and the presence of stenotic lesions. Mean cardiac output was 7.1 l/min and index 4.0 l/min and was positively correlated with graft flow. By obtaining this data surgical corrective action was taken in several patients prospectively thus removing the abnormalities and ensuring continued graft patency. The techniques described are reproducible and simple and can be carried out in less than five minutes with minimal patient discomfort or hazard.

Adult↗
PubMed1977

Changes in red cell, plasma, inulin, and total water compartments in rat femurs. Comparison of vitamin D deficiency and diphosphonate induced rickets.

The vascular space, as measured with the use of 99m-technetium-labelled red cells and 131I-serum albumin, as well as the 14C-inulin and 3H2O fluid compartments were measured in rats which had been made rachitic by the use of a low phosphate vitamin D-deficient diet. A similar group of rachitic animals fed vitamin D2 50 IU, 5 and 3 days prior to sacrifice and a weight-matched control group were also studied. The same spaces were measured in rats made rachitic by daily s.c. injections of ethane-1-hydroxy-1,1-diphosphonate (EHDP) for 4 weeks and a weight-matched saline injected control group. Findings indicated that the red cell and RISA spaces were unchanged in the untreated D-deficient group as compared to controls but increased after being repleted with vitamin D. By contrast, the vascular space was depressed in the EHDP-treated group. The water content was elevated in D-deficient rickets returning towards normal on healing, whilst both inulin and water spaces were increased in the EHDP-treated animals. Thus, while the extravascular space reflected the presence of osteoid, the vascular space depended on cellular turnover and the process of mineralization.

Animals↗
PubMed1977

Hypomagnesemic hypocalcemia. Early serum calcium and late parathyroid hormone increase with magnesium therapy.

A patient with short-bowel syndrome developed severe hypomagnesemia (0.2 mEq/liter) associated with symptomatic hypocalcemia (6.1 mg/100 ml). Parathyroid hormone (PTH) levels were normal but inappropriately low. During therapy with magnesium sulfate, an initial hypocalcemia was followed by a calcemic response without a change in PTH levels. This indicates improved bone responsiveness to circulating low levels of endogenous PTH with magnesium replenishment, which appears to be related to the restoration of magnesium-dependent cellular mechanisms. The additional observation of a slow and delayed increase in PTH, despite normal calcium levels, indicates improvement of hormone synthesis.

Calcium↗
PubMed1977

The calcium and vitamin D status in an elderly female population and their response to administered supplemental vitamin D3.

Recent reports have implicated the importance of impaired calcium absorption, inadequate dietary vitamin D, and low serum vitamin D levels in the genesis of metabolic bone diseases in the elderly. This study evaluated the dietary intakes of calcium and Vitamin D, calcium absorption, and serum 25 hydroxycholecalciferol (25 OH D) levels in a population of women (mean age 83 yrs) compared to healthy volunteers (mean age 35 yrs). Dietary intakes of both calcium and vitamin D and serum 25 OH D levels were found to be comparable in both groups. Calcium absorption was normal in the subjects studied and did not change significantly after two 2-week periods of oral supplementation with vitamin D3 in doses of 500 I.U./day and 10,000 I.U./day, although the serum 25 OH D levels rose significantly and comparably in both groups. Thus other etiological factors may play relevant roles in the causation of bone diseases in the elderly and unless deficient dietary or serum vitamin D levels are demonstrated, empirical supplementation with vitamin D should not be undertaken. The differences of the above findings from previously published data are discussed.

Absorption↗
PubMed1977

Technetium-99m-pyrophosphate bone scans in hyperparathyroidism.

Most patients with primary hyperparathyroidism have normal 5-hr bone-to-soft-tissue ratios for 99MTc-pyrophosphate. In contrast, all five patients with advanced secondary hyperparathyroidism in this study showed significant (p less than 0.001) increases of bone uptake. In the early period after parathyroidectomy, there was no quantitative or qualitative change in uptake. A limited decrease of bone uptake was observed only after prolonged periods of observation. In itself, parathyroid activity seems to have little direct influence on bone uptake of 99MTc-pyrophosphate.

Adolescent↗
PubMed1976

Observations on the mechanism of 99mTc-labeled phosphate complex uptake in metabolic bone disease.

This communication describes a series of clinical and animal in vivo and in vitro investigations designed to elucidate the mechanism of 99mTc-Sn-phosphate complex concentration in metabolic bone disease. Rachitic and lathyritic animals were used as experimental models. Based on these studies it is concluded that 99mTc alters the pharmacology of the phosphate complexes, in particular pyrophosphate, which was the test agent most extensively employed, so that the usual affinity for mineral is for the greater part replaced by organic matrix binding. There is also evidence to suggest the immature collagen moiety of the organic matrix is the prime target of 99mTc-Sn-phosphate complex binding. Specifically, the aldehyde groups of the collagen molecule are suspected as being the major site of interaction.

Aminopropionitrile↗
PubMed1976

Relationship between bone uptake of 99mTc-pyrophosphate and hydroxyproline in blood and urine.

In a group of hospital patients with various diseases, the urinary hydroxyproline-to-creatinine ratio showed a significant correlation (r = 0.63; p less than 0.001) with the 5-hr bone-to-soft-tissue ratio for 99mTc-pyrophosphate uptake. In patients on chronic hemodialysis, a similar correlation was found between the 5-hr bone-to-soft-tissue ratio and hydroxyproline levels in plasma and serum. The findings suggest that 99mTc-pyrophosphate binding by bone is related to collagen metabolism.

Aged↗
PubMed1976

Abnormal 99mTechnetium-tin-pyrophosphate bone scans in chronic renal failure.

A high incidence of abnormal 99mTechnetium-tin-pyrophosphate (99mTcPPi) is reported in a population of chronic renal failure patients. Using the 5 hour bone to soft tissue ratio as a quantitative index of increased uptake, 78% of 45 long-term dialysis patients and a similar proportion of non-dialyzed chronic renal failure patients were found to have increased uptakes. In animal studies using a uremic model, similar increased uptakes of 99mTcPPi was found with evidence of increased vascularity as reflected by red cell or plasma volumes in the bone or by the uptake of concomitantly administered 45Ca. The evidence suggests that the abnormal bone scans reflect abnormalities in collagen metabolism that occurs in the uremic state and that 99mTcPPi scans are useful in the diagnosis and management of renal osteodystrophy.

Animals↗
PubMed1975

The direct effect of calcium on the hyperparathyroidism of chronic renal failure.

1. The direct effect of calcium on the hyperparathyroidism of chronic renal failure was studied in rats with induced chronic renal failure, who were fed on a diet low in phosphate and who received supplemental phosphate by injection. They were given a normal (0-8%), or (0-1%) or high (1-7%) calcium diet. 2. The animals on the low calcium diet had larger parathyroids and more severe bone disease at the end of 4 weeks, indicating the importance of calcium intake in directly influencing the degree of hyperparathyroidism. 3. Increasing the calcium content of the diet from 0-8% to 1-7% produced no additional benefits.

Animals↗
PubMed1975

Effects of fluoride on bone in chronic renal failure.

Fluoride is concentrated in the bones of patients with chronic renal failure when fluoridated water is used during hemodialysis. Excessive osteoid is produced that is not normally mineralized and severe osteomalacia occurs. Electron microscopical examination of iliac crest bone biopsy specimens from four patients suggests that fluoride induces the synthesis of disarrayed collagen by the activated osteoblasts. Collagen fibers were found to be normal in size and in axial periodicity.

Adult↗
PubMed1975

Technetium-99m-pyrophosphate kinetics and imaging in metabolic bone disease.

A study was undertaken to investigate the behavior of 99mTc-Sn-pyrophosphate complex in metabolic bone disease. Of clinical importance was the generalized increased periarticular bone accumulation of the radiopharmaceutical in osteomalacia and in combined osteomalacia and osteitis fibrosa as found in patients with chronic renal failure. The pattern in primary hyperparathyroidism was variable. There was no correlation between the initial rates of accumulation of the radiophosphate complex or its bone to soft-tissue uptake ratio at 5 hr when compared with the degree of osteomalacia and osteitis fibrosa. It is postulated that the 99mTc-Sn-pyrophosphate complex has greater affinity for immature collagen than the crystal surface.

Adenocarcinoma↗
PubMed1975

Technetium-99m-pyrophosphate: studies in vivo and in vitro.

In rats with induced rickets, the uptake of 99mTcO4 and 99mTc-pyrophosphate per gram of bone was increased as compared with weight-matched controls. However, the uptake of radioactive calcium and 32P-pyrophosphate was similar in both rachitic and control animals, suggesting that the 99mTc label conferred specificity and favored the rachitic lesions. Employing the rat tibia in an in vitro system, 99mTcO4 uptake was predominantly in the organic bone matrix; radioactive calcium, 32P-pyrophosphate, or 14C-diphosphonate uptake was mainly in the bone mineral; and 99mTc-pyrophosphate, 99mTc-diphosphonate, and 99mTc-polyphosphate were found in both mineral and organic phases. By removal of both mineral and polysaccharide and by using agents that altered the degree of collagen fibril cross-linking, evidence was obtained suggesting the 99mTcO4 and 99mTc-pyrophosphate are preferentially bound by immature collagen.

Animals↗