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Biomedical subjects

L Kramer

Publications and source records attributed to L Kramer.

At least 109 records · Page 6Linked to original sources

Coccidiosis as a cause of transmural lymphocytic enteritis and mortality in captive Nashville warblers (Vermivora ruficapilla).

Transmural lymphocytic enteritis was diagnosed in thirteen Nashville warblers (Vermivora ruficapilla) during an epornitic with high mortality. In the intestinal lesions, asexual stages of coccidia were present within lymphocytes and asexual and sexual stages of coccidia were present within intestinal villar epithelium. Ultrastructurally, the infiltrating lymphocytes resembled granular ("intraepithelial") lymphocytes, a cell known to be important in the life cycle of some avian coccidia. Gross and histopathologic features of this enteritis resemble intestinal changes described for Isospora/Atoxoplasma spp. in other passeriformes and lymphoproliferative disease in gold-finches.

Animals↗

Felbamate.

Explore the source record for details and available documents.

Administration, Oral↗

Gamma-glutamylcysteine synthetase deficiency and hemolytic anemia.

gamma-Glutamylcysteine synthetase is one of the enzymes of glutathione (GSH) synthesis. A deficiency of this enzyme has been found only once previously in humans: it was associated with spinocerebellar degeneration and hemolytic anemia. We report the case of a woman, daughter of fifth cousins, who was gamma-glutamylcysteine-synthetase-deficient. Modest decreases in the amount of GSH in cultured lymphoblasts and fibroblasts could be documented. The amount of residual enzyme was insufficient to permit detailed studies of the characteristics of the mutant enzymes, but no major abnormality in its Km for cysteine and glutamic acid or in its heat stability were found. In contrast to the earlier report, the only manifestation of the enzyme deficiency was hemolytic anemia. This leads us to conclude that either the occurrence of neurologic symptoms in the other reported family was a chance association or that the clinical expression of this rare defect is pleomorphic.

Adult↗

Do protein and phosphorus cause calcium loss?

The widespread opinion that both protein and phosphorus cause calcium loss is examined. Controlled human studies show that commonly used complex dietary proteins, which have a high phosphorus content, do not cause calcium loss in adult humans. Similarly, a phosphorus intake of up to 2000 mg/d does not have adverse effects on calcium metabolism; however, the type of phosphate contained in carbonated beverages may not behave in the same manner. In contrast, a diet low in protein and phosphorus may have adverse effects on calcium balance in the elderly. Studies with adults suggest that high protein foods do not cause calcium loss.

Animals↗

Effect of zinc supplements on the intestinal absorption of calcium.

Pharmacologic doses of zinc are widely used as zinc supplements. As calcium and zinc may compete for common absorption sites, a study was carried out on the effect of a pharmacologic dose of zinc on the intestinal absorption of calcium in adult males. The analyzed dietary zinc intake in the control studies was normal, averaging 14.6 mg/day. During the high zinc study, 140 mg zinc as the sulfate was added daily for time periods ranging from 17 to 71 days. The studies were carried out during both a low calcium intake averaging 230 mg/day and during a normal calcium intake of 800 mg/day. Calcium absorption studies were carried out during the normal and high zinc intake by using an oral tracer dose of Ca47 and determining plasma levels and urinary and fecal excretions of Ca47. The study has shown that, during zinc supplementation, the intestinal absorption of calcium was significantly lower during a low calcium intake than in the control study, 39.3% vs 61% respectively, p less than 0.001. However, during a normal calcium intake of 800 mg/day, the high zinc intake had no significant effect on the intestinal absorption of calcium. These studies have shown that the high zinc intake decreased the intestinal absorption of calcium during a low calcium intake but not during a normal calcium intake.

Adult↗

Osteoporosis, calcium requirement, and factors causing calcium loss.

A large percentage of subjects receiving a normal calcium intake of 800 mg per day was in negative calcium balance and increasing the calcium intake to various levels up to 2200 mg per day showed a plateau of the calcium balance at the 1200 mg per day intake, indicating a threshold of calcium absorption at this intake level. Dietary factors, such as a phosphorus intake up to 2000 mg per day and complex proteins, such as red meat, do not cause calcium loss. Several commonly used drugs induce significant calcium loss, particularly aluminum-containing antacids, and, if used for prolonged periods of time, can contribute to the development of osteoporosis.

Adult↗

The effect of phosphorus on endogenous fecal calcium excretion in man.

The effect of phosphorus on the endogenous fecal calcium excretion was investigated in man by administering tracer doses of 47Ca intravenously in control studies and during phosphorus supplementation. The phosphorus intake was approximately 800 mg/day in control studies and 2000 mg during phosphorus supplementation of the constant diet. The studies were carried out during different calcium intake levels of approximately 200, 800, 1300, 2000, and 2600 mg/day. Following the dose of 47CaCl2, the values of the plasma levels, urinary, and fecal excretions of 47Ca were used to calculate the endogenous fecal calcium. None of these values differed significantly during phosphorus supplementation from those in corresponding control studies, irrespective of the calcium intake. During addition of phosphorus to the different calcium intakes, a consistent finding was a significant decrease of the urinary calcium and a slight, but not significant increase of the fecal calcium except during the 800 mg calcium intake.

Aged↗

The clinical application of an ELISA technique for the detection of antihistone antibodies.

A rapid reproducible technique for measuring antihistone antibodies is described in which unfractioned nuclear histones covalently bonded to plastic discs are employed in an ELISA system. All 20 patients with drug induced lupus erythematosus had antihistone antibodies, usually at high titer. In contrast, 22% of 18 asymptomatic patients with drug induced antinuclear antibodies (ANA), 15% of 20 patients with seropositive RA and 42% of 60 patients with systemic lupus erythematosus (SLE) had detectable antihistone antibodies. High titers of antihistone antibodies were not seen in drug induced ANA or RA. This assay differentiates between patients with drug induced lupus and drug induced ANA (p less than 0.01) and drug induced lupus erythematosus and SLE (p less than 0.01). In patients with SLE antihistone antibodies had no association with disease activity.

Antibodies, Antinuclear↗

The calcium requirement and factors causing calcium loss.

Studies carried out under strictly controlled conditions during different calcium intakes in adult males have shown that the average calcium balance was only slightly positive (+22 mg/day) during a calcium intake of 800 mg/day, the recommended dietary calcium intake, not taking into consideration dermal losses of calcium. During this calcium intake, the calcium balances were negative in 34% of the subjects studied. Increasing the calcium intake to 1200 mg/day resulted in a significant increase of the calcium balance; further increases to different intake levels up to 2300 mg/day did not improve the calcium balance further. Increasing the phosphorus intake up to 2000 mg/day as well as increasing the protein intake from 1 g/kg body weight to 2 g/kg, given as meat, did not have an adverse effect on calcium metabolism. A variety of drugs, notably aluminum-containing antacids, induced calcium loss. Increasing the calcium intake more than 10-fold from 200 to 2500 mg/day did not lower the blood pressure in a large number of normotensive patients and in a small number of hypertensive patients studied.

Antacids↗

Osteoporosis: calcium, fluoride, and aluminum interactions.

A gradual loss of bone occurs with age. There are indications in the literature that not only calcium but also fluoride may play an important role in maintaining the bone mass. In view of the high incidence of osteoporosis and its complications, and in view of the fact that fluoride is beneficial for the treatment of osteoporosis, studies have been carried out in this research unit to determine the retention and excretion of fluoride both during a normal dietary intake of fluoride and during fluoride supplementation. Another problem to be examined was to delineate whether certain substances interfere with the intestinal absorption of fluoride and of calcium. One such substance is aluminum contained in commonly used antacids. The use of small amounts of aluminum-containing antacids increased fecal fluoride significantly, thereby decreasing the intestinal absorption of fluoride. In addition, the small doses of aluminum-containing antacids also affected the metabolism of calcium and phosphorus, the primary effect being complexation of phosphorus in the intestine leading to phosphorus depletion. This change in phosphorus metabolism was associated with an increase of the urinary and fecal calcium excretion resulting in a negative calcium balance. The dual effect of aluminum, namely in causing calcium loss and inhibition of the intestinal absorption of fluoride, can result in adverse effects on bone which may contribute to bone loss.

Aluminum↗

Disseminated aspergillosis and pacemaker endocarditis.

Clinical and pathologic findings in a 65-year old woman with fever of unknown origin are described in this report. Generalized aspergillosis with endocarditis was demonstrated at autopsy. The patient had no recognized risk factors for the development of fungal infection. A functional transvenous pacemaker lead, inserted 2 years previously, was completely encased in a large infected thrombus and may have been the initial site of infection. Septicemia and endocarditis are rare but well-described complications of cardiac pacing, and should be considered in the differential diagnosis of fever of unknown origin in patients with pacemakers.

Aged↗