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Biomedical subjects

A A Dietz

Publications and source records attributed to A A Dietz.

At least 19 recordsLinked to original sources
PubMed1981

Aluminum concentrations in serum of hemodialysis patients.

Aluminum has been implicated in the etiology of the progressive dialytic encephalopathy. Data are presented on samples taken from patients on maintenance hemodialysis, during treatment. Aluminum was determined by electrothermal atomic absorption spectroscopy. Hemodialysis had no significant effect on serum aluminum concentrations, which ranged from 27 to 254 micrograms of Al per liter (1.00 to 9.42 mumol/L). Isolated ultrafiltration removed part of the serum aluminum, but most remained bound to a nonfiltrable component. These results are evaluated in the light of present knowledge concerning dialysis dementia.

Adult↗
PubMed1980

A family segregating for E1j and E1k at cholinesterase locus 1.

A family segregating for the A, J, and K alleles at cholinesterase locus 1 is described. Several further examples of the AJ and AK phenotypes occur in this family, and one member of the family, by genetic analysis, is phenotype JK. In relation to possible succinylcholine apnoea, phenotypes AJ, AK, and JK should all be considered vulnerable.

Adolescent↗
PubMed1979

Metabolic balance of aluminum studied in six men.

The metabolism of aluminum was followed in patients who were receiving strictly controlled diets, either unaltered or supplemented with aluminum-containing antacids. Aluminum was determined by atomic absorption spectrophotometry with a graphite furnace. All food, water, and medications were analyzed, as were aliquots of urine and stool collected throughout six-day periods. Patients were usually studied for five consecutive six-day periods on the same diet and aluminum intake. This study included six patients who were studied for seven to 21 such six-day periods. During control periods, when the patients were receiving less than 5 mg of aluminum per day, the balance was usually slightly negative, but when the diet was supplemented with antacids to contain 1--3 g of aluminum per day, an average positive balance of 23 to 313 mg of aluminum per day was observed for the total time on the same intake. Consecutive six-day periods while a subject was receiving antacids might show either positive or negative balances, but the average retention for 18--84 days on antacids was always positive. Thus the potential effects of the storage of aluminum in the tissues must be considered in the chronic administration of antacids.

Adult↗
PubMed1978

E1k, another quantitative variant at cholinesterase locus 1.

Two families segregating for the atypical (E1a) allele at cholinesterase locus 1 are described. Unusual results for dibucaine inhibition led to the recognition of a new allele (E1k) also segregating in these families. The enzymatic and immunological data are consistent with the hypothesis that E1k causes reduction of 'usual' (E1u) molecules by about 33%. Whether the reduction of E1u caused by E1k is caused by retarded synthesis or accelerated degradation of serum cholinesterase remains to be determined.

Cholinesterases↗
PubMed1978

Type B hepatitis after needle-stick exposure: prevention with hepatitis B immune globulin. Final report of the Veterans Administration Cooperative Study.

Hepatitis B immune globulin (HBIG) and immune serum globulin (ISG) were examined in a randomized, double-blind trial to assess their relative efficacies in preventing type B hepatitis after needle-stick exposure to hepatitis B surface antigen (HBsAG)-positive donors. Clinical hepatitis developed in 1.4% of HBIG and in 5.9% of ISG recipients (P = 0.016), and seroconversion (anti-HBs) occurred in 5.6% and 20.7% of them respectively (P less than 0.001). Mild and transient side-effects were noted in 3.0% of ISG and in 3.2% of HBIG recipients. Available donor sera were examined for DNA polymerase (DNAP) and e antigen and antibody (HBeAg; anti-HBE). Both DNAP and HBeAg showed a highly statistically significant correlation with the infectivity of HBsAg-positive donors. Hepatitis B immune globulin remained significantly superior to ISG in preventing type B hepatitis even when the analysis was confined to these two high-risk subgroups. The efficacy of ISG in preventing type B hepatitis cannot be ascertained because a true placebo group was not included.

Adolescent↗
PubMed1978

Determination of aluminum in biological samples by atomic absorption spectrophotometry with a graphite furnace.

Aluminum, generally considered non-essential and non-toxic, may accumulate in toxic amounts in the brain in cases of chronic renal failure. We describe a procedure for its analysis in biological fluids by atomic absorption spectrophotometry with a graphite furnace. No sample preparation is required and the procedure is sensitive at the appropriate concentrations. A sample of serum or urine is pipetted into the interior of the graphite tube, where it is sequentially dried, charred, and atomized. Precautions for sample handling are discussed and instrument settings are defined. Precision and accuracy of the method are evaluated, as are the effects of salts, protein content of serum, and specific gravity of urine. Serum of 23 persons who were not consuming aluminum-containing antacids contained 28 +/- 9 (SD) microgram of Al per liter (1.02 +/- 0.33 mumol/liter).

Aluminum↗
PubMed1977

Dual action of pancuronium on succinylcholine block.

The effects of pretreatment with both sub-paralyzing and paralyzing doses of pancuronium and d-tubocurarine, on the onset and duration of succinylcholine-induced neuromuscular blockade were evaluated and compared in 225 patients. D-tubocurarine antagonized both onset and duration of succinylcholine block, while pancuronium produced a dual effect, antagonizing the onset and potentiating the duration of succinylcholine block. Pretreatment with d-tubocurarine (0.07 mg/kg, 0.3 mg/kg and 0.6 mg/kg) increased the time to onset of succinylcholine paralysis from 28 to 118%, and decreased the duration from 16 to 37%. Pancuronium (0.02 mg/kg, 0.04 mg/kg and 0.08 mg/kg) also antagonized the onset of succinylcholine paralysis with increases of 32 to 114%, but potentiated its duration from 30 to 103% compared with succinylcholine alone in the same patients. Although pancuronium markedly inhibited serum cholinesterase in vitro (I50=5 X 10(-7) mol) there was only a 10% inhibition of cholinesterase in vivo after pancuronium 0.08 mg/kg.

Adult↗
PubMed1977

Purine metabolic cycle in normal and leukemic leukocytes.

Purine metabolism and reutilization pathways were studied as they applied to normal and leukemic leukocytes. The enzyme activities were expressed in terms of the quantity of protein extracted and per 10(10) cells. Whereas the protein extracted and the enzyme activities from normal lymphocytes were relatively constant, considerable variation was noted in cases of chronic lymphocytic leukemia (CLL). This variability in the properties of the leukemic cells suggests that the difference may be useful in the subclassification of the leukemias. The studies of the complete enzyme system were done with 300 million cells. The extraction of 350,000 normal lymphocytes/mul gave a soluble protein concentration of 1.46+/-0.16 mg protein per ml, and the yield from the same number of CLL lymphocytes varied between 0.72 and 8.32 mg protein per ml. The 5'-nucleotidase activity gave an inverse correlation with the amount of extractable protein. In individual cases of CLL, the protein concentrations and the 5'-nucleotidase activities were found on either side of the normal values. In most cases, the adenosine deaminase of CLL lymphocytic cell extracts was lower than normal, and the adenosine kinase was higher; in the CLL cells, these two enzymes gave a positive correlation with one another. Little or no difference was observed in the activities of the purine nucleoside phosphorylases in extracts of normal or leukemic lymphocytes and granulocytes. The hypoxanthine-guanine and adenine phosphoribosyltransferase activities increased in the leukemic granulocytes but almost always showed a decrease in the CLL lymphocytes when compared with the normal cells. Most of the leukemic cells had greater than normal activities of the enzymes synthesizing phosphoribosyl pyrophosphate when tested with the purines. The total nucleotide produced from adenine and guanine with adenine- and hypoxanthine-guanine phosphoribosyltransferase was about equal in normal and leukemic lymphocytes, but the proportion of the adenosine 5'-triphosphate in the product was much greater with the leukemic cells. This suggested that the ribosyltransferase activities were the same in both types of cells, but the nucleoside kinases and the nucleoside diphosphate kinases were more active in the leukemic cells. Inosine monophosphate dehydrogenase was less active than normal in the CLL cell extracts and was not directly related to the amount of inosine monophosphate generated from hypoxanthine.

Adenine Phosphoribosyltransferase↗
PubMed1977

A randomized, double blind controlled trial of the efficacy of immune serum globulin for the prevention of post-transfusion hepatitis. A Veterans Administration cooperative study.

A double blind, randomized, controlled trial has been conducted in 11 Veterans Administration hospitals during a 49-month period to compare the relative efficacies of immune serum globulin (ISG) and an albumin placebo for the prevention of post-transfusion hepatitis (PTH). A total of 2204 patients, of whom 1094 received ISG, participated in the study. The results indicate that ISG significantly reduced the incidence of icteric type non-B hepatitis only (inferred to be also type non-A hepatitis). Adverse reactions were rare, and the ISG did not significantly alter the incubation period or duration of the disease. The data suggest, however, that a similar reduction in type non-A, non-B hepatitis would have occurred had commercial blood been excluded from use. Analysis of the 241 patients who developed hepatitis indicates that type B hepatitis constituted less than 20% of the cases each year of the study. Furthermore, the efficacy of the ISG, manufactured in 1944, against apparent type non-A, non-B hepatitis suggests that this overlooked disease has existed from at least that time. Host- and transfusion-related factors that might have modified the development of PTH were examined. The use of commercial blood was observed to be the most important risk factor. It is concluded that the PTH incidence can be most effectively reduced by eliminating commercial donor blood, and continuing to screen volunteer donors for hepatitis B surface antigen (HBsAg) by sensitive procedures. Of prime importance is the need to define the agent(s) responsible for type non-A, non-B hepatitis.

Adult↗
PubMed1976

New allele at cholinesterase locus 1.

A family (H-J pedigree) segregating for the A and F alleles at cholinesterase locus 1 is described. Apparent anomalous results led to the recognition of a new allele (E1j) also segregating in the family. The data are consistent with the hypothesis that the the E1j causes reduction of 'usual' (E1u) molecules by about 66%. Whether this is because of retarded synthesis or accelerated degradation of serum cholinesterase remains to be determined.

Alleles↗
PubMed1976

E1j, a quantitative variant at cholinesterase locus 1: immunological evidence.

Sera of various phenotypes at serum cholinesterase locus 1, including the newly recognized phenotypes E1 aE1j, E1 uE1j, and E1 fE1J, were studied by immunodiffusion and rocket immunoelectrophoresis. The sera containing the E1j allele show reduced numbers of immunologically active cholinesterase molecules. This finding is consistent with the previously advanced hypothesis that E1j results in reduced numbers of circulating 'usual' (E1u) molecules. Whether this reduction is the result of the low rate of synthesis or of an increased rate of degradation of the cholinesterase remains to be determined.

Alleles↗