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Biomedical subjects

B Shapiro

Publications and source records attributed to B Shapiro.

At least 325 records · Page 18Linked to original sources

Sulphation factor (somatomedin activity) in experimental protein malnutrition in the rat.

In a rat model of protein malnutrition in which the failure of growth is a major feature, a low level of bioassayable sulphation factor activity was present in the serum, associated with normal levels of growth hormone and low insulin in the plasma. The administration of pharmacological doses of human or bovine growth hormone did not increase the amount of sulphation factor activity in the serum or the width of the tibial epiphyses in the protein-malnourished animals. The basal and serum-stimulated incorporation of 35SO2-4 into the costal cartilages of malnourished animals did not differ from that of controls, which suggests that the responsiveness of the end-organs was normal.

Animals↗

Generation of somatomedin activity in response to growth hormone and insulin from isolated perfused livers of normal and protein-malnourished rats.

The generation of somatomedin activity by isolated perfused livers was examined in protein-malnourished (4% casein diet) and well-nourished (controls, 20% casein diet) rats. There was significantly less somatomedin activity (measured by the porcine costal cartilage bioassay), after perfusion for 2 h, in the perfusates from the livers of malnourished rats both in hormone-free perfusates and perfusates containing hormones (10 microgram GH/ml, 1000 microunits insulin/ml or a combination of the two). A reduction in the somatomedin activity generated by the liver may be the mechanism responsible for the low serum level of somatomedin (in spite of raised or normal levels of growth hormone) in human or experimental protein malnutrition.

Animals↗

Language processor generation with BNF inputs: methods and implementation.

This paper describes an SLR (1) parser generator written in SAIL for the PDR-10. It accepts grammars defined in a BNF formalism and produces a SAIL program module which is the bottom-up parser produced from the grammar. This module may then be compiled and loaded with semantic routines to produce a language processor. The generator is written in SAIL with a heavy emphasis placed on the use of the LEAP facilities of SAIL for the manipulation of the data structures required for the generator.

Computers↗

A phylogenetic study of sulphation factor activity in 26 species.

Somatomedin (sulphation factor) activity was measured in 26 species by a porcine cartilage bioassay. Although non-dialysable inhibitory factors were present in many species, sulphation factor activity was present in the sera of all the vertebrates studied but was absent from the invertebrates.

Animals↗

Free DNA in the serum of cancer patients and the effect of therapy.

A radioimmunoassay for ng quantities of DNA was developed. [125l]lododeoxyuridine-labeled DNA was used as the antigen, and the serum of a lupus erythematosus patient served as the source of antibody. The level of free DNA in the serum of 173 patients with various types of cancer and in 55 healthy individuals was determined by this radioimmunoassay. DNA concentration in the normal controls had a range of 0 to 100 ng/ml with a mean of 13 +/- 3 ng/ml (S.E.). For comparison purposes, the range of 0 to 50 ng/ml was designated as normal, and 93% of controls were found in this range. In the cancer patients, the DNA concentration ranged from zero to mug levels with a mean of 180 +/- 38 ng/ml. Fifty % of the patients values were found in the range of 0 to 50 ng/ml; the other 50% were between 50 and 5000 ng/ml. No correlation could be seen between DNA levels and the size or location of the primary tumor. Significantly higher DNA levels, however, were found in the serum of patients with metastatic disease (mean of 209 +/- 39 ng/ml), as compared to nonmetastatic patients (mean 100 +/- 30, p less than 0.02). After radiation therapy in lymphoma, lung, ovary, uterus, and cervical tumors, the levels decreased in 66 to 90% of the patients, whereas in glioma, breast, colon, and rectal tumors, the DNA levels decreased only in 16 to 33% of the patients. Generally, the decrease in DNA concene of tumor size and reduction of pain. Conversely, when DNA levels either increased or remained unchanged, a lack of response to the treatment was noted. Of 17 patients who died within a year, 13 showed DNA levels that remained high or unchanged, whereas only 4 showed lower levels during treatment. Persistent high or increasing DNA levels in the circulation, therefore, may signal a relapse and are probably a poor prognostic sign. The relatively high percentage (50%) of cancer patients with apparently normal DNA levels would suggest that this test may have low diagnostic value. It should be pointed out, however, that all these patients represent a selected group considered for radiation therapy, usually after surgery and/or chemotherapy. It is possible that a better correlation between DNA levels and cancer will be obtained prior to the initiation of treatment. On the other hand, DNA in the serum may be an important tool for the evaluation of therapy or the comparison of different regimens.

Cell Survival↗

Free DNA in the serum of rheumatoid arthritis patients.

Seventy patients with classical or definite rheumatoid arthritis (RA) were studied in an attempt to correlate the serum levels of free DNA with other features. In 26 patients (37%), levels of DNA ranging from 100-540 ng/ml, with a mean of 187 ng/ml, were found. In additional seven patients with a mean of 257 ng/ml, low levels of anti-DNA-antibody were observed. The remaining of 37 patients (53%) had levels of 0-80 ng/ml in their sera, with a mean of 39 ng/ml. All three groups differed significantly (p less than 0.01) from the control group of 61 healthy individuals, who had levels of 0-80 ng/ml with a mean of 13 ng/ml. The high levels of free DNA were commonly found in patients with more severe symptoms who had active RA for less than 10 years, whereas patients with longer duration of disease showed lower levels of DNA. In addition, elevated DNA levels were found more commonly in patients seronegative for rheumatoid factor (RF). Other clinical features did not show significant differences among these patients. The implications of these findings to the pathogenesis of the disease are discussed.

Arthritis, Rheumatoid↗

Phosphatidic acid metabolism in rat liver microsomes.

Rat liver microsomes contain phosphatidate phosphatases which split phosphatidic acid into inorganic phosphate and diacylglycerol and a system of phospholipases and lipases, which split phosphatidic acid into free fatty acids, glycerol and inorganic phosphate. In the presence of ATP,CoA and [1-14C]palmitate, part of the monoacyl-sn-glycerol 3-phosphate formed by phospholipase action is reesterified, yielding radioactive phosphatidic acid. The sum of di- and triacylglycerols formed from phosphatidic acid in the presence of ATP and CoA exceeded the amount of diacylglycerol formed in their absence. The yield of neutral lipids from sn-glycerol 3-phosphate and monoacyl-sn-glycerol 3-phosphate markedly exceeded that from phosphatidic acid. Comparison of the yields of di- and triacylglcerols from glycerol-labelled and fatty-acid-labelled phosphatidic acid was used to establish the extent of deacylation and reacylation. About 60% of the diacylglycerol was formed by direct dephosphorylation. The triacylglycerols, on the other hand, were formed almost exclusively from recycled phosphatidic acid.

Adenosine Triphosphate↗

Problems in the differential diagnosis of narcolepsy versus schizophrenia.

The authors discuss the problems of accurately diagnosing narcolepsy when patients manifest the auxiliary symptoms of this disorder, i.e., cataplexy, hypnagogic hallucinations, and sleep paralysis, which conclude that misdiagnosis of narcolepsy can be avoided if clinicians are aware that this illness can simulate a psychiatric disorder and if they give careful attention to the histroy of the patient's illness.

Adult↗

Role of testosterone and its metabolites in the differentiation of the mammary gland in rats.

The capacity of various androgens to virilize the differentiating mammary gland in the female rat fetus has been determined. Testosterone, 5alpha-androstane-3alpha, 17beta-diol (3alpha-diol), and dihydrotestosterone (DHT) virilize the anlagen of the mammary gland by suppressing nipple formation but 5alpha-androstane-3beta, 17beta-diol, androsterone, and dehydroepiandrosterone sulfate do not affect female mammary differentiation. However, unlike the genitalia and wolffian ducts of the female rat fetus in which the masculinizing potency of DHT and 3alpha-diol is greater than that of testosterone, testosterone is more potent than its metabolites DHT and 3alpha-diol, in virilizing the mammary gland. The results suggest that testosterone is the fetal androgen mediating masculine development of the mammary gland.

Androgens↗

Liver enlargement demonstrated by scintigraphy in rheumatoid arthritis.

Scintigraphic scanning employing technetium-99m sulfur colloid was used to assess the size of the liver and spleen in 32 consecutive patients with rheumatoid arthritis. The data were correlated with clinical and laboratory assessment. Seven patients had enlarged livers, three enlarged spleens. An expected correlation of liver enlargement with Sjögren's syndrome did not materialize. Splenic enlargement and liver enlargement were discordant. Liver enlargement correlated best with elevations of rheumatoid factor as measured by latex fixation. As liver enlargement is not an appreciated feature of rheumatoid arthritis, these findings suggest that hepatomegaly need not necessarily imply adverse treatment results or the development of lymphoproliferative disorders.

Adult↗

Partial purification and properties of microsomal phosphatidate phosphohydrolase from rat liver.

Microsomal phosphatidate phosphohydrolase (phosphatidate phosphatase EC 3.1.3.4) was solubilized and fractionated to yield at least two distinct enzymatically active fractions. One, denoted FA, was non-specific, had a relatively high Km for phosphatidic acid and was insensitive to inhibition by diacylglycerol. The second fraction, FB, was specific for phosphatidates, had a low Km, and was inhibited, non-competitively, by diacylglycerol. FA exhibited a sigmoid substrate-activity curve. The isolated FB aggregated to particles of about 10(6) in the absence of salts and could be dissociated by the addition of monovalent cations at ionic strength 0.4-0.6 to about 2-10(5) daltons and thereby doubled its activity. Dissociation was time- and temperature-dependent. F- was inhibitory. Divalent ions were not required for the activity of FA or FB and inhibited at concentrations exceeding 1 mM.

Animals↗

Radioimmunoassay for nanogram quantities of DNA.

A direct competitive binding radioimmunoassay for DNA has been developed, using 125I-iododeoxyuridine-labelled DNA as the antigen and the serum from a patient with systemic lupus erythematosus. The assay is sensitive in the range of 25 to 1000 ng/ml of DNA. The sensitivity is determined by the affinity of the antibody: this SLE serum contains a component with an association constant of 9.6 X 10(-5) l/mol active at high dilution (1/10,000). Any biological material, such as serum, synovial fluid or tissue extracts can be tested directly. No interference has been found by DNAse in normal serum, or inhibition by mononucleotides or RNA. Native or denatured DNA from different sources (Escherichia coli, salmon sperm, calf thymus and human placenta) either purified or not, competes equally well for the antibody in this system.

Antibody Specificity↗