[ICN Congress--Gunilla recommends international congresses. Interview by Elisabet Forslind].
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Canada↗
Biomedical subjects
G Samuelsson
Publications and source records attributed to G Samuelsson.
Molecular cloning and biochemical characterization of carbonic anhydrase from Populus tremula x tremuloides.
A leaf cDNA library from hybrid aspen, Populus tremula x tremuloides, was constructed. From this two different cDNA clones, denoted CA1a and CA1b, encoding a chloroplastic carbonic anhydrase (CA) were isolated and DNA sequenced. Analysis of the deduced amino acid sequences showed that the isolated CAs belong to the beta-CA family, and have identities around 70% to other dicotyledonous plant CAs. The two hybrid aspen cDNA clones display a high nucleotide sequence identity, only 12 nucleotides differ. Since only one gene copy of this soluble chloroplastic CA is present in the nuclear genome, we postulate that the two isolated cDNA clones are alleles. Northern blot hybridization revealed a CA transcript of ca. 1300 bases, 140 bases shorter than in pea. Western and northern blot hybridizations on crude protein extracts and on total RNA, respectively, isolated from stem and leaves, showed that hybrid aspen CA is expressed specifically in the leaf under the growth conditions used. Based on the deduced amino acid sequence, the mature hybrid aspen CA enzyme subunit has a molecular mass of 24.8 kDa. The enzyme was over-expressed in Escherichia coli, and purified by affinity chromatography. Biochemical characterization showed that the protein structure and the CO2-hydration activity are similar to the pea enzyme. Molecular characterization of a CA from a perennial plant has not previously been performed, and it demonstrates that both the structure and activity of hybrid aspen CA resembles CAs from annual plants.
Amino Acid Sequence↗
Blood pressure in relation to medical, psychological and social variables in a population of 80-year-olds. Survival during 6 years.
OBJECTIVES: To relate elevated blood pressure in 80-year-olds to symptoms, life satisfaction and survival. DESIGN: Examinations of medical, psychological and social factors every year between 80 and 86 years of age. SETTING: Primary health care in the city of Lund in southern Sweden. SUBJECTS: Three-hundred and thirty-three persons living in the city of Lund and born in 1908. Participation rate was 67%. INTERVENTION: Abnormal findings were further examined and treated. MAIN OUTCOME MEASURES: Symptoms, blood pressure, laboratory values, psychological factors, cognition, living conditions, and survival. RESULTS: Hypertension according to the definition used was found in 70%. Women were over-represented (P < 0.05). Amongst persons with alleged hypertension, diuretics (P < 0.001) and 'other cardiovascular drugs' (P < 0.001) were more often used. Analgesics were more often used amongst assessed hypertensives (P < 0.05). Those with assessed hypertension scored better in testing of cognition compared to nonhypertensives (P < 0.05), and less often lived in institutions (P < 0.001). Assessed hypertensives had a better survival than alleged hypertensives during the following 7 years (P < 0.01). CONCLUSIONS: Eighty-year-olds with assessed hypertension in the consulting room showed fewer symptoms and had a better cognition and survival than alleged hypertensives (those with a history of hypertension).
Aged↗
The Swedish Centenarian Study: a multidisciplinary study of five consecutive cohorts at the age of 100.
UNLABELLED: Centenarians born 1887-91, who lived in southern Sweden were asked to participate in this multidisciplinary study (N = 164). Of the survivors (N = 143), 70 percent agreed (N = 100). The purpose was to describe the population from physical, social, and psychological points of view; to characterize centenarians with various health conditions and diverse degrees of autonomy and life satisfaction; and to identify factors at 100 years that predict future survival. RESULTS: Eighty-two percent were women, 25 percent lived in their own home, 37 percent in old age homes, and 38 percent in nursing homes. Socioeconomic status showed a similar distribution compared to nationally representative data. Fifty-two percent managed activities of daily living with or without minor assistance. The incidence of severe diseases was low. In 39 percent a disorder of the circulatory system was found. Thirty-nine percent (women) and 11 percent (men) had had at least one hip fracture. Twenty percent had good hearing and good vision. Twenty-seven percent were demented according to DSM III-R criteria. Means on cognitive tests (word-list, digit-span, learning, and memory) were lower compared to seventy to eighty year old groups. The variation in performance was extremely widespread. Personality profiles (MMPI) indicated that the centenarians were more responsible, capable, easygoing and less prone to anxiety than the population in general. Extensive neuropathological investigation revealed no major diseases or large lesions but mild through multiple changes. RESULTS suggest that centenarians are a special group genetically. A causal structure model emphasized body constitution, marital status, cognition and blood pressure as particularly important determinants for survival after 100 years.
Aged↗
A cDNA coding for glutathione S-transferase from the unicellular green algae Coccomyxa sp.
A cDNA coding for glutathione S-transferase (GST) was cloned and sequenced from the unicellular green algae Coccomyxa sp. The predicted 215 amino acid polypeptide (23.9 kDa, pI 5.3) is most similar to the theta-type GSTs found in a variety of different eukaryotic organisms. Within this sub-class, the Coccomyxa GST is 42% identical (63% similar) to the flatfish Pleuronectes platessa homologue, and 24 to 35% (49-57%) to other theta-type GST's.
Amino Acid Sequence↗
Discovery of an algal mitochondrial carbonic anhydrase: molecular cloning and characterization of a low-CO2-induced polypeptide in Chlamydomonas reinhardtii.
In green unicellular algae, several polypeptides are induced upon exposure to limiting CO2. We report here on the localization and characterization of one of these, a 22-kDa polypeptide in Chlamydomonas reinhardtii. This nuclear-encoded polypeptide is induced in the mitochondria by a lowering of the partial pressure of CO2 in the growth medium from 5% to air CO2 levels. Sequencing of two different cDNA clones coding for the polypeptide identified it as a 20.7-kDa beta-type carbonic anhydrase (CA; carbonate dehydratase, carbonate hydro-lyase, EC 4.2.1.1). The two clones differ in their nucleotide sequences but code for identical proteins, showing that this CA is encoded by at least two genes. Northern blot hybridization reveals that mRNA transcripts are only present in cells transferred to air CO2 levels. A comparison of the deduced amino acid sequence with those of other beta-CAs shows the largest degree of similarity with CA from the cyanobacterium Synechocystis (50% identity and 66% similarity). To our knowledge, this is the first identification and characterization of a mitochondrial CA from a photosynthetic organism.
Amino Acid Sequence↗
Regulation of the supply of cytosolic oxaloacetate for mitochondrial metabolism via phosphoenolpyruvate carboxylase in barley leaf protoplasts. I. The effect of covalent modification on PEPC activity, pH response, and kinetic properties.
The regulation of the supply of oxaloacetate (OAA) for mitochondrial metabolism via phosphoenolpyruvate carboxylase (PEPC) by covalent modification is studied in barley (Hordeum vulgare L.) leaf protoplasts in light or darkness as well as under photorespiratory or non-photorespiratory conditions. Extracts for studies on in vivo PEPC phosphorylation were prepared from barley leaf protoplasts by rapid filtration, fractionating the cell within less than 1 s. Measurements of in vitro PEPC activity were performed on samples quickly frozen in liquid nitrogen to break the cell and stop metabolism and thus preserve the in vivo activation state. The relative PEPC phosphorylation state increased upon illumination and decreased upon redarkening under photorespiratory and non-photorespiratory conditions. PEPC activity measured in the presence of malate (3 mM) under photorespiratory conditions showed the same response indicating that a light-induced increase in PEPC activity and decrease in malate sensitivity is caused by an increased phosphorylation level of the PEPC protein. PEPC activity was pH dependent. At the physiological cytosolic pH, activity was suboptimal, but most sensitive towards malate inhibition and glucose 6-phosphate stimulation. The presence of malate increased the sensitivity of PEPC activity towards pH changes. The response of PEPC activity to changing pH was not affected by changes in the activation state of the enzyme. The Km (phosphoenolpyruvate, PEP) is about 1 mM. Upon illumination the Km (PEP) decrease significantly. Vmax was unaffected by the light treatment. The presence of physiological concentrations of glucose 6-phosphate decreased Km (PEP) 5- to 10-fold and increased Vmax by about 35%. The effect of glucose 6-phosphate was strongest (up to 7-fold) at subsaturating PEP concentrations stimulating PEPC activity to nearly maximal rates. The results show that an increase in PEPC phosphorylation state causes an increase in PEPC activity as well as in substrate affinity leading to an increased production of OAA in the light.
Cytosol↗
Regulation of the supply of oxaloacetate for mitochondrial metabolism via phosphoenolpyruvate carboxylase in barley leaf protoplasts. II. Effects of metabolites on PEPC activity at different activation states of the protein.
The regulation of the supply of oxaloacetate (OAA) for mitochondrial metabolism via phosphoenolpyruvate carboxylase (PEPC) by metabolites is studied in barley (Hordeum vulgare L.) leaf protoplasts in light or darkness as well as under photorespiratory or non-photorespiratory conditions. Measurements on PEPC activity were performed on samples quickly frozen in liquid nitrogen to break the cell and stop metabolism and thus preserve the in vivo activation state. Glycine, serine, pyruvate, acetyl-CoA, glycolate, fructose 1,6-bisphosphate, fructose 2,6-bisphosphate and ADP had no significant effect on PEPC activity. Malate, aspartate and glutamate were strong inhibitors of PEPC activity decreasing the activity more in light versus darkness. However, at the physiological cytosolic concentration of these metabolites under the respective conditions, inhibition of PEPC activity was about the same with the exception of aspartate which inhibits more under non-photorespiratory than under photorespiratory conditions. 2-Oxoglutarate and glyoxylate decreased PEPC activity by 20 to 40% in the range of its physiological cytosolic concentration. Inhibition by physiological cytosolic concentrations of glutamine was limited. Glucose 6-phosphate, fructose 6-phosphate, 3-phosphoglycerate, dihydroxyacetonphosphate and P(i) stimulated PEPC activity significantly in their physiological cytosolic concentration range. Physiological cytosolic concentrations of glucose 6-phosphate and fructose 6-phosphate activated PEPC activity to about the same extent under all conditions applied, while 3-phosphoglycerate and dihydroxyacetonphosphate stimulating stronger under non-photorespiratory versus photorespiratory conditions. Moreover, dihydroxyacetonphosphate stimulated PEPC activity more in light versus darkness under non-photorespiratory conditions. P(i) activation of PEPC activity decreases in light versus darkness under non-photorespiratory conditions. Stimulation of PEPC activity by citrate in its physiological concentration range is limited. Glucose 1-phosphate and AMP activated PEPC activity only at concentrations higher than their physiological levels in the cytosol. Determinations of PEPC activity in the presence of different malate/glucose 6-phosphate ratios revealed that glucose 6-phosphate totally relieved the inhibitory effect of malate. The regulatory properties of PEPC activity will be discussed in relation to its functions in C3 plants.
Amino Acids↗
Isolation of two new antiinflammatory biflavanoids from Sarcophyte piriei.
Two new flavano flavanone glycosides, diinsininol (1) and diinsinin (2), have been isolated from the rhizome of Sarcophyte piriei, together with one known flavanone glycoside, naringenin 5-glucoside. Their structures were elucidated on spectroscopic evidence as 5,7,3',4'-tetrahydroxyflavanyl-7-O-beta-glucosyl-(4beta-8; 2beta-O-7)-eriodietyol (1) and 5,7,3',4'-tetrahydroxyflavanyl 7-O-beta-glucosyl-(4beta-8;2beta-O-7)-naringenin (2), respectively. The compounds were tested for their ability to inhibit prostaglandin synthesis, with 1 and 2 giving IC50 values of 9.20 microM and 13.14 microM, respectively, and in the inhibition of platelet-activating-factor-induced exocytosis, IC50 values of 49 and 39 microM.
Animals↗
Purification and characterisation of an intracellular carbonic anhydrase from the unicellular green alga Coccomyxa.
An intracellular carbonic anhydrase (CA; EC 4.2.1.1) was purified and characterised from the unicellular green alga Coccomyxa sp. Initial studies showed that cultured Coccomyxa cells contain an intracellular CA activity around 100 times higher than that measured in high-CO2-grown cells of Chlamydomonas reinhardtii CW 92. Purification of a protein extract containing the CA activity was carried out using ammonium-sulphate precipitation followed by anion-exchange chromatography. Proteins were then separated by native (non-dissociating) polyacrylamide gel electrophoresis, with each individual protein band excised and assayed for CA activity. Measurements revealed CA activity associated with two discrete protein bands with similar molecular masses of 80 +/- 5 kDa. Dissociation by denaturing polyacrylamide gel electrophoresis showed that both proteins contained a single polypeptide of 26 kDa, suggesting that each 80-kDa native protein was a homogeneous trimer. Isoelectric focusing of the 80-kDa proteins also produced a single protein band at a pH of 6.5. Inhibition studies on the purified CA extract showed that 50% inhibition of CA activity was obtained using 1 microM azetazolamide. Polyclonal antibodies against the 26-kDa CA were produced and shown to have a high specific binding to a single polypeptide in soluble protein extracts from Coccomyxa cells. The same antiserum, however, failed to cross-react with soluble proteins isolated from two different species of green algae, Chlamydomonas reinhardtii and Chlorella vulgaris. Correspondingly, antisera directed against pea chloroplastic CA, extracellular CA from C. reinhardtii and human CAII, showed no cross-hybridisation to the 26-kDa polypeptide in Coccomyxa.(ABSTRACT TRUNCATED AT 250 WORDS)
Amino Acid Sequence↗
Intracellular carbonic anhydrase of Chlamydomonas reinhardtii.
An intracellular carbonic anhydrase (CA; EC 4.2.1.1) was purified to homogeneity from a mutant strain of Chlamydomonas reinhardtii (CW 92) lacking a cell wall. Intact cells were washed to remove periplasmic CA and were lysed and fractionated into soluble and membrane fractions by sedimentation. All of the CA activity sedimented with the membrane fraction and was dissociated by treatment with a buffer containing 200 mM KCI. Solubilized proteins were fractionated by ammonium sulfate precipitation, anionic exchange chromatography, and hydrophobic interaction chromatography. The resulting fraction had a specific activity of 1260 Wilbur-Anderson units/mg protein and was inhibited by acetazolamide (50% inhibition concentration, 12 nM). Final purification was accomplished by the specific absorption of the enzyme to a Centricon-10 microconcentrator filter. A single, 29.5-kD polypeptide was eluted from the filter with sodium dodecyl sulfate-polyacrylamide gel electrophoresis sample buffer, and a 1.5 M ammonium sulfate eluate contained CA activity. In comparison with human CA isoenzyme II, the N-terminal and internal amino acid sequences from the 29.5-kD polypeptide were 40% identical with the N-terminal region and 67% identical with an internal conserved region. Based on this evidence, we postulate that the 29.5-kD polypeptide is an internal CA in C. reinhardtii and that the enzyme is closely related to the alpha-type CAs observed in animal species.
Acetazolamide↗
Apheresis technologies: an international perspective.
The developments in apheresis techniques and their clinical applications world-wide are technologically driven. In the past, apheresis survey statistics have high-lighted both the differences by region in clinical practice and in the types of technologies utilized. Such differences have provided a basis for the scientific and clinical assessments of these apheresis technologies and their clinical outcomes and have stimulated the marketing and business development of new technologies world-wide. A review of the regional practices and technologies utilized provides a perspective on the future role of apheresis and its developments in clinical practice. While technology is a driving force for the development of new techniques for clinical practice, it is not the only market force. For technology introduction, several other important issues need to be considered. Regulations at the local and, most importantly, the federal level impact the timing for new technology introduction. Reimbursement by healthcare payers is critically important from the initiation of the development of a technology through its clinical use. Clinical trials are critically important to show the safety and clinical- and cost-effectiveness of the technology in order for payers to provide reimbursement for its use, but these trials are sometimes long and costly. Research funding availability at the governmental and commercial levels critically impacts new technology investigation and its introduction. Apheresis technology developments offer new hopes and promises for the clinical team; however, their development, introduction, and utilization will be influenced by the prevailing market forces.
Blood Component Removal↗
Confirmation of a major target epitope of human natural IgG and IgM anti-pig antibodies: terminal galactose alpha -1,3-galactose.
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Animals↗
Inventory of plants used in traditional medicine in Somalia. IV. Plants of the families Passifloraceae-Zygophyllaceae.
Thirty-seven plants are listed, which are used by traditional healers in the central and southern parts of Somalia. For each species are listed: the botanical name with synonyms, collection number, vernacular name, medicinal use, preparation of remedy and dosage. Results of a literature survey are also reported including medicinal use, substances isolated and pharmacological effects. Three plants which should have been included in Part I of the series have been added and some corrections to that paper have been made. With these additions the series comprises 180 different plant species, distributed in 59 plant families.
Animals↗
Family network and mortality: survival chances through the lifespan of an entire age cohort.
This study relates certain family network variables (martial status and number of children) to chances of survival. Through multivariate analysis, survival is also related to social class, social mobility, migration and local environment, and legitimacy of birth. All persons in a local birth cohort born in the years 1902 and 1903 were followed in population records from birth until eighty years of age. The group comprised 487 individuals with a dropout rate of 4 percent. Univariate survival analysis between twenty to eighty years of age showed widows and also divorced women to have a significantly higher survival than those still married and never married. Never married men and women had the lowest survival rates. The number of children was not associated with survival for neither men nor women when controlled for marital status. Multiple regression survival analysis showed different patterns for males and females. The risk of not surviving to eighty years of age for men resulted from a combination of being single, downward social mobility, a father in the manual working class group and few children, with being single as the strongest predictor. For women the strongest predictor for death before eighty was the category single and/or married (as opposed to earlier married). The combination of being single/married, high migration, earlier life mainly in rural areas, and having few children were predictors in the model of death before eighty. Thus, for both men and women marital status was the strongest predictor for survival but in different ways.
Adult↗
Inventory of plants used in traditional medicine in Somalia. II. Plants of the families Combretaceae to Labiatae.
Fifty-nine plants are listed, which are used by traditional healers in the central and southern parts of Somalia. For each species are listed: the botanical name with synonyms, collection number, vernacular name, medicinal use, preparation of remedy and dosage. Results of a literature survey are also reported including medicinal use, substances isolated and pharmacological effects.
Medicine, Traditional↗
Inventory of plants used in traditional medicine in Somalia. III. Plants of the families Lauraceae-Papilionaceae.
Thirty-five plants are listed, which are used by traditional healers in the central and southern parts of Somalia. For each species are listed: the botanical name with synonyms, collection number, vernacular name, medicinal use, preparation of remedy and dosage. Results of a literature survey are also reported including medicinal use, substances isolated and pharmacological effects.
Humans↗
Pharmacologically active phenylpropanoids from Senra incana.
Coniferaldehyde, scopoletin, sinapaldehyde, and syringaldehyde were isolated from an aqueous extract of Senra incana. All four compounds inhibited prostaglandin synthetase in a dose-dependent way. Compared to aspirin, the potency of coniferaldehyde and scopoletin was about five times higher, whereas syringaldehyde and sinapaldehyde had about half the potency of this reference compound. On topical application, sinapaldehyde and scopoletin dose-dependently inhibited ethyl phenylpropiolate-induced edema of the rat ear. The active dose range was 1-10 micrograms/ear. Higher doses had a lower effect. Syringaldehyde was active in the range 20-100 micrograms/ear, whereas the effect of coniferaldehyde was inconclusive. Coniferaldehyde and sinapaldehyde inhibited electrically induced contractions of the guinea pig ileum in a dose-dependent way. Syringaldehyde showed a weak inhibition at a concentration of 550 microM.
Acrolein↗