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Biomedical subjects

J Hoffman

Publications and source records attributed to J Hoffman.

At least 181 records · Page 10Linked to original sources
PubMed1984

Immunological and isoelectric focusing study of beta-glucocerebrosidase from normal and Gaucher disease.

Comparison of normal and Gaucher disease beta-glucocerebrosidase by agarose isoelectric focusing (IEF) demonstrated additional bands at the pI-6 area seen within the mutated enzyme, while both normal placenta and spleen enzyme preparations manifest only major activity at pI-5. Antiglucocerebrosidase antibodies precipitated both normal and pathological enzymes, however, more antibodies were needed to reach an equivalence with the normal enzymes than with the Gaucher's. Cross reactivity of the IEF isozymes were detected by direct immunodiffusion on the prefocused gel.

Female↗
PubMed1984

Lysosomal glycosidases in mouse peritoneal macrophages stimulated in vitro with soluble and insoluble glycans.

Mouse peritoneal macrophages stimulated with insoluble glycans in vitro release high amounts of acid hydrolases, N-acetyl-beta-D-glucosaminidase, beta-D-glucuronidase, and beta-D-galactosidase. The most potent of the stimulatory glycans is a beta-1,3-D-glucan isolated from yeast cell walls. Up to 50% of total enzyme activity was found in the medium after stimulation with this glycan for three days. Agarose, another insoluble glycan containing an alternating sequence of the disaccharide beta-1,3-D-galactose-alpha-1,4-3,6-anhydro-L-galactose units was less potent. The soluble beta-1,3-D-glucan laminaran, which also contains small amounts of mannitol, was not able to induce release of acid glycosidases from macrophages. The release was independent of serum since macrophages cultured under serum-free conditions showed nearly the same pattern of enzyme activities, both in the cells and media. There was no increased release of the acid hydrolase alpha-D-mannosidase after stimulation with the insoluble beta-1,3-D-glucan for three days. The release of the lysosomal glycosidases was not due to cell death, since only small amounts of the cytoplasmic enzyme lactate dehydrogenase were found in the culture media. Insoluble polystyrene latex particles were not able to stimulate mouse macrophages to release lysosomal glycosidases. Tritiated glycans (amylose, dextran, laminaran, the insoluble beta-1,3-D-glucan, and agarose) and the p-nitrophenyl-glycopyranoside derivatives were used as substrates to investigate whether the macrophages contained or released glucanases capable of degrading alpha-1,4-D-glucans, alpha-1-6-D-glucans, beta-1,3-D-glucans, and agarose respectively. We conclude that the glycans were not degraded in macrophage cultures during the time period tested nor were the enzymes induced in macrophages by the glycans during in vitro culture for seven days.

Animals↗
PubMed1984

Stimulatory effect of immobilized glycans on macrophages in vitro.

Mouse macrophages were cultured on chemically modified plastic dishes. On dishes covered with immobilized glycans, the macrophages were stimulated as judged by increased 14C-glucosamine incorporation, increased cytostatic and cytolytic capacities and by morphology as seen by scanning electron microscopy. The corresponding soluble glycans did not have the capacity to stimulate macrophages as measured by these criteria. Plastic surfaces covered with polyethylenimine showed stimulation of the macrophages with regard to some of the parameters measured. These results may indicate that the stimulation is a multistep process and that, contrary to earlier findings, it is not a prerequisite for stimulation that the glycan be intracellular. The results support the idea that a fixed steric arrangement of glycans is necessary for the stimulation of macrophages in vitro.

Amylose↗
PubMed1984

Sonography and computed tomography in the diagnosis of carcinoma of the gallbladder.

The computed tomographic and sonographic findings of 26 patients with gallbladder carcinoma were reviewed, and the problems and pitfalls encountered with these imaging techniques are discussed. The most common finding, a mass filling or replacing the gallbladder, was seen in 42% of the patients. A mass protruding into the gallbladder was seen in 23%, and diffuse asymmetric thickening of the gallbladder wall in 15%. Recommendations are made to avoid some of the diagnostic problems encountered. With careful and meticulous technique early carcinoma of the gallbladder may be detected with greater frequency by cross-sectional imaging techniques.

Aged↗
PubMed1983

Absolute configuration of a chiral CHD group via neutron diffraction: confirmation of the absolute stereochemistry of the enzymatic formation of malic acid.

Neutron diffraction has been used to monitor the absolute stereochemistry of an enzymatic reaction. (-)(2S)malic-3-d acid was prepared by the action of fumarase on fumaric acid in D2O. After a large number of cations were screened, it was found that (+)(R) alpha-phenylethylamine forms the large crystals necessary for a neutron diffraction analysis. The subsequent structure determination showed that (+)(R) alpha-phenylethylammonium (-)(2S)malate-3-d has an absolute configuration of R at the CHD site (i.e., the C3 carbon of malate). This result confirms the absolute stereochemistry of fumarate-to-malate transformation as catalyzed by the enzyme fumarase.

Malates↗
PubMed1983

The value of ultrasound in the diagnosis of popliteal artery aneurysms.

Although popliteal artery aneurysms are among the most common type of peripheral artery aneurysm, they may be difficult to diagnose until complications such as peripheral embolization, acute thrombosis and rupture occur. Pressure on adjacent structures may cause neurological symptoms and venous thrombosis. The diagnosis of peripheral artery aneurysms is usually made by physical examination and arteriography. Recently, ultrasound of the popliteal space has been found to be very useful in the diagnosis of popliteal artery aneurysms. It is therefore important to recognize the value of ultrasound for imaging popliteal artery aneurysms and to use this readily available non-invasive modality in patients in which physical examination and/or angiography of the popliteal fossa is equivocal. We present one case of a popliteal artery aneurysm which was missed by angiography and physical examination in which ultrasound was very important in diagnosing this aneurysm pre-operatively, and two cases in which the ultrasound examination confirmed the presence of the popliteal artery aneurysm but better delineated its size than did angiography.

Aged↗
PubMed1983

Behavioral and cardiac rhythmicity during mother-father-stranger infant social interaction.

In an effort to understand the temporal organization of infant physiologic and behavioral systems during social interaction with adults, spectral and cross-spectral analyses of infant heart rate and mother-father-stranger-infant behavioral data are described herein for a 3-month-old infant during face-to-face social interaction with her parents and a stranger. This infant's heart rate rhythms were stronger during social interaction with both mother and father than with a stranger. Infant behavioral rhythms were associated with (high coherence) the parents' behavioral rhythms, but not with those of the stranger. Furthermore, infant heart rate and infant behavioral rhythms showed high coherence with all three adults. Although these findings are preliminary, based on a case study and need replication, they generate intriguing hypotheses. This technique of studying the rhythmicity of infant social interaction with spectral analysis suggests that the 3-month-old infant's behavior and heart rate are synchronized during interaction with all three adults; however, the infant and adult behavioral rhythms are synchronous only with mother and father and not with an unfamiliar stranger.

Child Behavior↗
PubMed1982

Mechanisms of anticoagulant effects of some sulphated polysaccharides.

The anticoagulant activity of a partially reduced sulphated alginic acid, a partially reduced aminated and sulphated alginic acid and sulphated guaran have been studied. The anticoagulant activities in the APTT assay were 28, 39 and 70 IU/mg respectively. None showed any activity in anti-factor Xa assay. Studies on binding to Antithrombin III - Sepharose showed that sulphated guaran and a fraction of the aminated and sulphated alginic acid was bound, whereas no binding occurred with sulphated alginic acid. The inhibition of thrombin activity by these polysaccharides was studied in purified systems with or without added Antithrombin III, using both fibrinogen clotting and chromogenic peptide substrate assays. The two alginic acid preparations showed Antithrombin III-dependent inhibition of thrombin, whereas the sulphated guaran inhibits both by Antithrombin III-dependent and independent mechanisms.

Alginates↗