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Biomedical subjects

L Anderson

Publications and source records attributed to L Anderson.

At least 289 records · Page 16Linked to original sources
PubMed1984

Stability of noxythiolin solutions stored in plastic and glass containers.

The stability of two different concentrations (1% and 2.5% w/v) of noxythiolin (Noxyflex and Noxyflex S) stored at a variety of temperatures (4, 20 and 37 degrees C) in both plastic and glass bottles has been examined over a period of 40 days. During this period noxythiolin solutions held at 20 degrees and 37 degrees C attained equilibrium (K = 0.285 +/- 0.015 mol/l). Neither noxythiolin nor its degradation products (N-methylthiourea and formaldehyde) were absorbed by the plastic (polypropylene) containers used. Therefore, noxythiolin solutions can be stored in certain plastic (polypropylene) containers under the same conditions as recommended for glass bottles.

Absorption↗
PubMed1984

Saliva lithium levels in children: their use in monitoring serum lithium levels and lithium side effects.

The reliability of saliva lithium levels in monitoring serum lithium levels in children taking lithium has rarely been studied, despite the potential usefulness of such a study and despite a number of adult studies focusing on the technique. In a study of 61 aggressive school-age children diagnosed as undersocialized, aggressive conduct disorder, a subsample of 21 children received lithium. Saliva lithium levels aided in monitoring side effects, and in 15 of the 21 children simultaneous saliva and serum lithium levels were done. These were highly correlated (r = 0.83) and the saliva to serum ratio was 2.53 across subjects. The results indicate that future work with larger numbers of children should study the ratio of saliva to serum lithium levels. Adult studies have shown that there is too great a variability in saliva to serum lithium level ratios to support the use of a fixed saliva to serum lithium ratio. This may not be the case in children. Seventeen children from the lithium subsample experienced 41 lithium-related side effects. Most children suffered side effects on relatively high doses of lithium, and those few who experienced side effects on low dosage had saliva lithium levels that were proportionately high. However, it remains unclear whether saliva lithium can be used to monitor side effects.

Child↗
PubMed1984

Syme amputation in children: indications, results, and long-term follow-up.

Syme amputations are not always effective. Heel pad migration, skin sloughs, and problems with prosthetic fitting may complicate a seemingly simple procedure. We reviewed 69 Syme amputations performed in 62 children at the Los Angeles Shriners Hospital between 1956 and 1980. The major indication was leg length discrepancy, due to either paraxial fibula hemimelia (33 cases) or proximal focal femoral deficiency (19 cases). The average age at amputation was 5.6 years, with an average follow-up of 10.5 years (range 1-25 years). The results were assessed by a combination of chart review, patient recall examinations, and questionnaires. Satisfaction in adulthood was high. Early complications included three skin sloughs and one infection. Late complications included 2 retained os calcis apophyses, 1 exostosis, and 16 cases of heel pad migration. Only one of the heel pad group required revision; prosthetic adjustment resolved the others. Prosthetic knees were often too low because of failure to limit the length of the stump appropriately. Syme amputation should be considered a primary reconstructive procedure, rather than a last resort, in fibula hemimelia and proximal femoral focal deficiency.

Adolescent↗
PubMed1983

Glucosamine-derived phospholipids in Escherichia coli. Structure and chemical modification of a triacyl glucosamine 1-phosphate found in a phosphatidylglycerol-deficient mutant.

Certain Escherichia coli mutants defective in phosphatidylglycerol biosynthesis accumulate novel glucosamine-derived phospholipids. We previously demonstrated that the simplest of these substance (lipid X) is a diacylglucosamine 1-phosphate bearing beta-hydroxymyristoyl groups at positions 2 and 3 (Takayama, K., Qureshi, N., Mascagni, P., Nashed, M. A., Anderson, L., and Raetz, C. R. H. (1983) J. Biol. Chem. 258, 7379-7385). We now report the structural characterization of a triacylglucosamine 1-phosphate (designated lipid Y) that is also found in these mutants. Hydrolyzates of Y contain 2 mol of beta-hydroxymyristate and 1 mol of palmitate/mol of glucosamine. In the lipid, one of the beta-hydroxymyristates is amide-linked at position 2, while the two other fatty acyl groups are ester-linked. Fast atom bombardment mass spectrometry is used to confirm that Y is a monosaccharide derivative and that the molecular weight of Y as the free acid (C50H96NO13P) is 950.29. Analysis of Y by proton NMR spectroscopy at 200 MHz reveals that the anomeric configuration is alpha. Further, one of the esterified fatty acid residues is attached to the 3 OH of the sugar, while the second is linked to an OH moiety of a hydroxymyristate. The 4 and 6 OH groups of the sugar are unsubstituted, as in E. coli lipid X. To establish the precise location of each esterified fatty acyl residue, we subjected Y to a very mild alkaline hydrolysis in the presence of triethylamine. This resulted in the selective removal of a single hydroxymyristoyl group. The triethylamine-treated derivative (lipid Y) has a molecular weight of 723. NMR spectroscopy of Y shows that the 3 OH of the sugar is no longer substituted, while the beta OH of the remaining amide-linked hydroxymyristate is still esterified with palmitate. On the basis of these findings, we propose that lipid Y has the same fundamental structure as lipid X, except for the additional presence of a palmitoyl moiety on the N-linked hydroxymyristate. Presumably, lipid Y is synthesized from X by a selective acylation reaction.

Endotoxins↗
PubMed1983

Fatty acyl derivatives of glucosamine 1-phosphate in Escherichia coli and their relation to lipid A. Complete structure of A diacyl GlcN-1-P found in a phosphatidylglycerol-deficient mutant.

We have determined the complete structure of a glycolipid (designated lipid X) previously found to accumulate in certain Escherichia coli mutants defective in phosphatidylglycerol synthesis (Nishijima, M., and Raetz, C.R.H. (1979) J. Biol. Chem. 254, 7837-7844). Based on fast atom bombardment mass spectrometry and proton nuclear magnetic resonance studies, this substance is an acylated metabolite of glucosamine 1-phosphate. Lipid X of E. coli has a Mr = 711.87 as the free acid (C34H66NO12P) and contains two beta-hydroxymyristate moieties, one attached as an amide at the 2 position and the other as an ester at the 3 position of the sugar. It has free hydroxyl groups at the 4 and 6 positions, and the anomeric configuration is alpha. The structure of lipid X from E. coli closely resembles the reducing end subunit of lipid A, and it might represent a very early precursor in the biosynthesis of lipid A. To our knowledge, fatty acyl derivatives of glucosamine 1-phosphate have not been reported previously.

Escherichia coli↗
PubMed1983

Permanent Iodine-125 implants in head and neck cancer.

One hundred twenty-four patients were treated with advanced recurrent head and neck cancer for palliation with radioactive permanent Iodine-125 (125I) implants. Complete regression occurred in 71% of the 118 lesions for which evaluation was possible and greater than 50% regression occurred in 18%; no meaningful regression occurred in 11%. Local recurrence of cancer was subsequently seen in 21% of the lesions which had regressed completely, in 55% of those which had regressed incompletely, and in 100% of those which had not regressed. The incidence of serious complications was 5.5%. Overall, in 64% of the instances the implanted lesions remained controlled until the patient's death, usually due to progression of cancer elsewhere in the body. It is concluded that permanent 125I implants offer useful palliation to the patient with recurrent head and neck cancer with a minimum of toxicity and inconvenience. Because of their low toxicity even after prior full-course external radiation therapy, the authors are currently investigating their use as planned adjunct to external radiation therapy and chemotherapy in the initial definitive management of patients with locally advanced head and neck cancer.

Brachytherapy↗
PubMed1983

Oligosaccharides from "standardized intermediates". Synthesis of a branched tetrasaccharide glycoside isomeric with the blood-group B, type 2 determinant.

Building block derivatives of the component monosaccharides were used to construct the tetrasaccharide glycoside 15, in which an alpha-D-Galp-(1 leads to 4)-D-Gal linkage replaces the alpha-(1 leads to 3) linkage of the human blood-group B, type 2, determinant structure. The initial coupling of 2-O-benzoyl-3,6-di-O-benzyl-4-O-(tetrahydropyran-2-yl)-alpha-D-galactopyranosyl chloride to allyl 2-acetamido-3,6-di-O-benzyl-2-deoxy-beta-D-glucopyranoside was followed by selective deprotection of the disaccharide product, either at O-4' (to give 8) or O-2' (to give 3). The conversion of 8 into 15 involved successive coupling with tetra-O-benzyl-alpha-D-galactopyranosyl bromide (8 leads to 11), O-debenzoylation at O-2' (11 leads to 12), coupling with tri-O-benzyl-alpha-L-fucopyranosyl bromide (12 leads to 14), and O-debenzylation by hydrogenolysis (14 leads to 15). Alternatively, 3 was alpha-L-fucosylated to give 6, and 6 was selectively deprotected at O-4' to give 7. However, attempts to alpha-D-galactosylate 7 were unsuccessful. The unsubstituted forms of the intermediate disaccharide (8) and trisaccharide (12) glycosides were obtained by appropriate deblocking procedures.

ABO Blood-Group System↗
PubMed1983

Oligosaccharides from "standardized intermediates". The 2-amino-2-deoxy-D-galactose analog of the blood-group O(H) determinant, type 2, and its precursors.

The selectively benzylated glycoside allyl 2-acetamido-4,6-di-O-benzyl-2-deoxy-beta-D-galactopranoside (4) was prepared from the corresponding derivative of 2-acetamido-2-deoxy-D-glucose via the p-bromobenzenesulfonate and the benzoate. 2-O-Benzoyl-3,4,6-tri-O-benzyl-alpha-D-galactopyranosyl (10) was obtained from allyl 6-O-benzyl-2-O-(2-butenyl)-alpha-D-galactopyranoside via known intermediates. To complete the sequence, the 1-propenyl 3,4,6-tri-O-benzyl galactoside was successively converted into the 2-benzoate, the free sugar, and the chloride 10. A fully protected form (11) of the trisaccharide alpha-L-Fucp-(1 leads to 2)-beta-D-Galp-(1 leads to 4)-D-GalNAc was then synthesized by coupling 10 to 4, partially deblocking the disaccharide product, and L-fucosylating the resulting intermediate. Cleavage of the O-benzyl groups from 11, with concomitant saturation of the allyl group, gave the propyl beta-glycoside of the unsubstituted trisaccharide.

ABO Blood-Group System↗
PubMed1983

Intravesical chemotherapy in urinary bladder cancer.

Monthly instillation therapy with Adriamycin in a standardized dose of 300 ng/ml/h together with a phosphate buffer at pH 7.4 seems to give satisfactory results in patients with primary bladder carcinoma in situ and in patients with secondary carcinoma in situ of the bladder who have previously received full courses of irradiation. The side-effects are transient and few.

Carcinoma in Situ↗
PubMed1983

[Adriamycin instillations in carcinoma in situ of the bladder].

Several authors have described the regressive effect of the instillation of adriamycin on the cell appearance of carcinoma in situ. This applies to both weekly and monthly administration. The problem lies in the interpretation of the cytologic picture after instillation. DNA analysis could possibly improve the diagnostic reliability.

Carcinoma in Situ↗
PubMed1983

Inhibition of Na+-Ca2+ exchange in rat brain by amiloride.

Amiloride (N-amidino-3,5-diamino-6-chloropyrazine carboxamide) reversibly inhibits Na+-dependent 45Ca2+ uptake (Na+-Ca2+ exchange) by plasmalemma-enriched vesicles prepared from microsomes of rat cerebral cortex and by vesicles from osmotically shocked synaptosomes. The drug inhibits Na+-dependent Ca2+ uptake in a competitive manner with a KI of 0.25-0.34 mM. Na+-dependent 45Ca2+ efflux from vesicles is also inhibited by extravesicular amiloride. The drug does not appear to affect nonmitochondrial ATP-dependent Ca2+ transport in these vesicle preparations. Membranes containing Na+-Ca2+ carrier can be solubilized in Na+-cholate and reconstituted into phospholipid vesicles. Na+-dependent Ca2+ uptake by the vesicles is inhibited by amiloride.

Adenosine Triphosphate↗