Biomedical subjects

S Bunge

Publications and source records attributed to S Bunge.

4 recordsLinked to original sources

PubMed1992

A comparison of leaf thionin sequences of barley cultivars and wild barley species.

Leaf thionins of several barley cultivars and wild barley species were analysed. We found large differences in the numbers of leaf thionin genes in different Hordeum species. While, for instance, cultivars of Hordeum vulgare (Section Hordeum) contain more than 50 copies of thionin genes per haploid genome, the numbers are much lower in Hordeum species belonging to the sections Critesion and Stenostachys. The apparent number of genes correlates with the concentration of leaf thionin and its mRNA, which differs more than 100-fold among various Hordeum species. Leaf thionins are synthesized as high molecular weight precursor proteins that contain a signal peptide domain, a thionin domain and an acidic polypeptide domain. Analysis of cDNA clones of leaf thionins revealed a family of related transcripts. When the predicted amino acid sequences of the precursor molecules of wild barley species were compared, differences in the sequence variability of the three domains became apparent. The frequency of amino acid exchanges is much higher within the thionin domain than in the signal peptide and acidic polypeptide domains. The amino acid exchanges within the thionin domain do not occur at random but are confined to variable regions that alternate with highly conserved areas. Conserved regions comprise mostly cysteine residues and adjacent amino acids and may be important for the correct formation of the specific disulphide configuration of thionins.

Amino Acid Sequence↗

PubMed1992

Mutation analysis of the iduronate-2-sulfatase gene in patients with mucopolysaccharidosis type II (Hunter syndrome).

Iduronate-2-sulfatase (IDS) cDNA from fibroblasts of nine patients with Hunter syndrome (mucopolysaccharidosis type II) was screened for mutations using single strand conformation polymorphism analysis. Direct sequencing revealed a number of different mutations including missense or nonsense point mutations, deletions of one, two, or 60 base pairs, and a 22 base pair-insertion. Mutations of these types probably account for most IDS gene defects as only about 20% of Hunter patients have a complete deletion or gross structural alteration of their IDS gene. Thus the broad clinical variability amongst the Hunter patients may be due to the extensive genetic heterogeneity seen. The relationship between genotype and clinical phenotype is analysed in 12 Hunter patients.

Adolescent↗

PubMed1990

Plasma glucose and free fatty acids modulate the secretion of growth hormone, but not prolactin, in the rhesus and Java monkey.

In 11 freely moving rhesus and 5 Java monkeys the plasma GH, PRL, and cortisol responses to suppression and elevation of plasma glucose and FFA concentrations were studied. Blood was sampled and infusions given via chronic jugular catheters, extended via a swivel into the adjacent room. In the rhesus monkeys, the mean plasma GH concentration rose during insulin-induced hypoglycemia from 4.7 +/- 1.9 to 17.4 +/- 2.5 micrograms/L at 60 min (P less than 0.001), and the mean plasma cortisol concentration from 320 +/- 55 to 700 +/- 133 nmol/L at 90 min (P less than 0.001). The mean plasma PRL concentration (basal value, 5 +/- 2.3 micrograms/L) did not change significantly. During glucose-induced hyperglycemia, the mean plasma GH concentration oscillated between 2.0-5.2 micrograms/L from 60-360 min (no significant change). Large GH secretory episodes occurred during hyperglycemia in individual animals. During nicotinic acid-induced plasma FFA suppression, the mean plasma GH concentration increased from 3.7 +/- 0.6 to 17.9 +/- 2.3 micrograms/L at 270 min (P less than 0.001). During lipid-induced plasma FFA elevation, the mean plasma GH concentration decreased consistently from 6.5 +/- 1.0 micrograms/L to values between 1.3 +/- 0.2 and 2.6 +/- 0.6 micrograms/L from 60-360 min (P less than 0.01). Plasma PRL and cortisol concentrations were not affected by plasma FFA changes. Compared with the spontaneous plasma GH pattern in a previously studied group of rhesus monkeys, the mean plasma GH concentration was increased during hypoglycemia and plasma FFA suppression. It was strongly suppressed during plasma FFA elevation and slightly suppressed during hyperglycemia. Similar effects were observed in the Java monkeys, although hyperglycemia tests were not performed. We conclude the following. 1) In rhesus and Java monkeys, as in man, GH secretion is stimulated by plasma FFA suppression and is inhibited by plasma FFA elevation. In both species, acute hypoglycemia stimulates the secretion of GH and cortisol. 2) These nonhuman primates differ from man in that hyperglycemia only weakly inhibits GH secretion in the rhesus monkey, if at all (Java monkeys had no hyperglycemia tests), and in neither species does acute hypoglycemia stimulate the secretion of PRL. 3) Both primate species can serve as models for the metabolic modulation of GH secretion in man, although a suppressive effect of hyperglycemia remains to be proven.

Animals↗

PubMed1979

Therapy of cluster headache with histamine H1 and H2 receptor antagonists.

Treatment with the histamine H2 receptor antagonist, cimetidine, alone and/or in combination with the histamine H1 receptor antagonist, chlorpyramine, in 13 patients showed that cimetidine alone was ineffective. 7 of 9 patients taking the combination of H1 and H2 receptor antagonists responded well to the treatment; in 1 patient, medication was ineffective and in 1 patient, success was doubtful. In 3 patients with chronic cluster headache, the effect faded after 4 weeks. The results are discussed.

Cimetidine↗