Inge-Bert Täljedal | Umeå University (original) (raw)

Papers by Inge-Bert Täljedal

Biochemical journal. Cellular aspects, 1969

Granules were prepared from micro-dissected pancreatic islets of obese- hyperglyeaemic mice. This... more Granules were prepared from micro-dissected pancreatic islets of obese- hyperglyeaemic mice. This fraction contained 60% of the insulin, 30% of the cytochrome oxidase, 16% of the acid phosphatase activity and 20% of the protein present in whole islets. The isolated granules retained a heavy metal during fractionation. Optimum conditions for granule stability were low ionic strength and pH 6, the granules being unexpectedly fragile at pH 7-4. The stability of the granules was unaffected by sucrose in the concentration range 50-320mM, but 1% (w/v) sodium deoxycholate released all insulin. A solubilizing effect was also noted with ATP and citrate. Spinning through 1-6 M-sucrose yielded a further purification in relation to mitochondria and acid-phosphatase-carrying particles but virtually no purification in relation to protein. Electron microscopy revealed that the major contaminants were rough-surfaced vesicles and membranes. A separation of granules from acid phosphatase was achieved by phase distribution in polyethylene glycol and dextran. The location of the enzyme to the interphase was so pronounced in systems buffered with lithium phosphate that the technique may be used for future purification of acid-phosphatase-carrying particles from the $-cells. A major part of the insulin content of the pancreatic ,B-cells is normally stored in cytoplasmic granules surrounded by smooth membranes. Infor- mation about the biochemical characteristics of these granules can therefore be expected to contribute to our understanding of insulin release. In the present study, micro-dissected islets con- taining more than 90% of ,B-cells (Hellman, 1965) were subjected to various fractionation procedures. This approach made possible systematic analyses of the granule stability under various conditions in vitro. Materials. About 100 5-6-month-old obese-hyper- glycaemic mice (gene symbol obob; Ingalls, Dickie & Snell, 1950; Hellman, 1965) of both sexes were starved overnight and killed by decapitation. After rapid excision of the pancreas, 30-60 islets were isolated by micro-dissection (Hellerstrom, 1964) in a solution of 320mM-sucrose adjusted to pH6-0. The islets were pooled and homogenized by means of a Perspex micro-homogenizer in 100p. of a

Le repos de la guerrière, 2023

Secondo Antonio Rosmini-Serbati, l’idea dell’essere è unicamente innata e forma fondamentale dell... more Secondo Antonio Rosmini-Serbati, l’idea dell’essere è unicamente innata e forma fondamentale dell’esperienza. Provando a dimostrare l’origine dell’idea di similitudine nel rapporto tra cose reali e loro rappresentazioni mentali, Rosmini involontariamente lascia pensare che forse anche quest’idea sia innata. In modo platonico respinge “il terzo uomo” (regresso infinito), cioè la nota critica di Aristotele per quanto riguarda l’idea di similitudine. Il suo è un ragionamento circolare. Perciò in questa analisi concludiamo che l’idea di similitudine dovrebbe essere considerata innata e forma epistemologica nella stessa misura dell’idea di essere. [According to Antonio Rosmini, the idea of being is a uniquely innate and fundamental form for experience. Trying to demonstrate that the idea of similarity originates in the relation between real things and their mental representations, Rosmini involuntarily encourages the thought that this idea is also innate. In a Platonic mode, he rejects the Third Man argument, i.e. Aristoteles' critical comment concerning infinite regress. Rosmini argues in a circle. It is concluded that the idea of similarity is as good a candidate for being innate as is the idea of being.]

Partendo dall’osservazione critica del razionalista-soggettivista Erik Olof Burman (1845–1929) ch... more Partendo dall’osservazione critica del razionalista-soggettivista Erik Olof Burman (1845–1929) che Antonio Rosmini (1797–1855) rappresenti una gnoseologia troppo oggettiva, si e provato a illuminar ...

Histology and histopathology, 2002

Tyrosine hydroxylase (TH) is co-expressed with islet hormones in the fetal mouse pancreas. In the... more Tyrosine hydroxylase (TH) is co-expressed with islet hormones in the fetal mouse pancreas. In the adult animal, the enzyme has been considered as a marker of ageing beta-cells. By immunohistochemical staining, we analyzed the expression of TH-like immunoreactivity (TH-LI), insulin-LI (INS-LI) and somatostatin-LI (SOM-LI) in adult mouse islets, in situ and after isolation and transplantation to kidney. In pancreas in situ, most TH-LI cells expressed INS-LI while less than 5% expressed SOM-LI. The total number of TH-LI cells/mm2 was significantly increased directly after isolation and in 0-day, 12-week and 52-week old grafts, but not in 3-day grafts. The proportion of TH-LI cells expressing SOM-LI increased after transplantation, amounting to about one-third by 52 weeks. As expressed per unit islet area, the frequencies of both TH/INS and TH/SOM cells increased significantly in the transplants. The results demonstrate that TH occurs in both beta-cells and D-cells of adult islets. In b...

Biochemical Journal, 1979

Experiments with isolated pancreatic islets or dispersed islet cells from non-inbred ob/ob mice w... more Experiments with isolated pancreatic islets or dispersed islet cells from non-inbred ob/ob mice were performed to test the hypothesis that free radicals, notably OH., mediate the diabetogenic toxicity of alloxan. Accumulation of 86Rb+ by whole islets and exclusion of Trypan Blue by dispersed cells were used as previously validated criteria of islet-cell viability. Alloxan alone drastically inhibited the Rb+ accumulation and significantly decreased the frequency of cells excluding Trypan Blue. Enzymic scavengers of O2.- and H2O2 or non-enzymic scavengers of OH. or singlet oxygen were added to the incubation medium and tested for their ability to protect against these effects of alloxan. Superoxide dismutase, catalase, dimethyl sulphoxide, benzoate, and mannitol counteracted the effects of alloxan in both cytotoxicity assays. Significant protection of the Rb+-accumulating capacity was also afforded by butanol, caffeine, theophylline, NADH, NADPH and, to a small extent, NAD+. Urea has ...

Biochemical Journal, 1970

Some analytical functions were tested for goodness of fit to standard curves in radio-immunoassay... more Some analytical functions were tested for goodness of fit to standard curves in radio-immunoassays of insulin (Hales & Randle, 1963). Letting a, b and c be parameters, and y the radioactivity measured at an insulin concentration of x, excellent fit was obtained with the function 1/(y+c)=ax+b. This function was associated with a smaller variance around y and a greater number of sign changes for the residuals (calculated radioactivity minus observed radioactivity) than any of the following: 1/y=axc+b; y=aebx+c; y=a+bx+cx2+dx3. The mean number of sign changes of the residuals in 50 separate assays of mouse insulin was within the 95% confidence interval expected for a correct model. The function that was found to be applicable to assays of mouse, human and ox insulins should be useful in routines for computer processing of insulin assay data and may also prove applicable to other radio-immunoassays.

Biochemical Journal, 1977

Suspensions of islet cells were prepared by shaking pancreatic islets from non-inbred ob/ob mice ... more Suspensions of islet cells were prepared by shaking pancreatic islets from non-inbred ob/ob mice in a Ca2+-free buffer. The cells were incubated with or without 20 mM-alloxan, and subsequently with Trypan Blue. The uptake of Trypan Blue by cell nuclei was analysed by microscope photometry and by counting the frequency of cells appearing stained on visual inspection. Cells classified as stained or unstained by inspection showed no overlap in nuclear absorbance. Suspensions not exposed to alloxan contained 70-80% of unstained cells. Alloxan markedly decreased the frequency of unstained cells, an effect counteracted by 5 or 20 mM-D-glucose. The spectrum of Trypan Blue in islet-cell nuclei was red-shifted by about 20 nm. A similar red-shift was observed on adding the dye to solutions of albumin or histones, but not on mixing the dye with DNA. Binding to basic proteins may explain the concentrative uptake of Trypan Blue in dead cells and contribute to the oncogenic transformation of phag...

Biochemical Journal, 1972

The effects of p-chloromercuribenzoic acid and chloromercuribenzene-p-sulphonic acid on pancreati... more The effects of p-chloromercuribenzoic acid and chloromercuribenzene-p-sulphonic acid on pancreatic islets were studied in vitro. Obese–hyperglycaemic mice were used as the source of microdissected islets containing more than 90% β-cells. p-Chloromercuribenzoic acid and chloromercuribenzene-p-sulphonic acid stimulated insulin release at concentrations of 0.01mm or above. This stimulation was significantly inhibited by the omission of Ca2+or the addition of adrenaline, diazoxide or 2,4-dinitrophenol. p-Chloromercuribenzoic acid or chloromercuribenzene-p-sulphonic acid did not interfere with the insulin-releasing ability of glucose. Micro-perifusion experiments revealed that the release of insulin in response to organic mercurial occurred almost instantaneously, was reversible, and was biphasic. The two mercurials inhibited glucose transport as well as glucose oxidation, and increased the mannitol and sucrose spaces of isolated islets. Compared with the effects on insulin release, thos...

Idealistic Studies, 2013

Berkeley's 'esse is percipi' has been criticized for implying epistemological solipsism, the main... more Berkeley's 'esse is percipi' has been criticized for implying epistemological solipsism, the main argument being that different minds cannot harbor numerically one and the same idea. Similarly, C. J. Boström, the dominating Swedish philosopher in the 19th century, was early scorned because his principle of esse est percipi allegedly contradicts the simultaneous claim that two spirits (God and a human, or two humans) can perceive the same thing under qualitatively different appearances. Whereas the criticism against Berkeley is here regarded as valid, it is argued that Boström successfully defended himself by employing a dual concept of meaning, resembling Frege's Sinn and Bedeutung some thirty years later, and by postulating an ontology that permits human minds to share in the divine ideas that constitute reality.

Philosophy of the Social Sciences, 2010

According to a U.S. court ruling, intelligent design (ID) theory is religious in nature, not scie... more According to a U.S. court ruling, intelligent design (ID) theory is religious in nature, not scientific, and must not be taught in schools. In opposition, Fuller argues for a closer rapport between science and religion. Here it is emphasized that any allegedly scientific conclusion from design in nature to the existence of God is a hypothesis subject to the same quality norms as empirical hypotheses in general. By quotations from his Iter Lapponicum, Linnæus is summoned in support of a strictly immanent conception of science, against Fuller’s suggestion that Linnæus’ personal piety could be a reason for considering ID scientific.

Medicine, Health Care and Philosophy, 2004

The health theories of Nordenfelt and Boorse are compared. Critical attention is focused on Norde... more The health theories of Nordenfelt and Boorse are compared. Critical attention is focused on Nordenfelt's description of his theory as one of holistic welfare, contrasting with Boorse's analytical and statistical approach. Neither theory is found to give an entirely satisfactory account of 'health' in scientific medicine or common usage. Because Nordenfelt attenuates the ontological significance of organs and organ parts and simplifies the role of statistics, his theory is regarded as weakly holistic. Boorse underrates the importance of non-statistical evaluation. A mediating position, termed 'strong holism' is suggested as a way of integrating normative and statistical elements in a more adequate health concept.

Hormone Research, 1974

The uptake of 3H-labelled glibomuride wasstudied in microdissected pancreatic islets of ob/ob- mi... more The uptake of 3H-labelled glibomuride wasstudied in microdissected pancreatic islets of ob/ob- mice . The islets rapidly accumulated this insulin-releasi

Acta Endocrinologica, 1993

Treatment of NMRI mice with cyclosporin A (25 mg/kg body wt) for 11 days caused a marked fall in ... more Treatment of NMRI mice with cyclosporin A (25 mg/kg body wt) for 11 days caused a marked fall in pancreas insulin content, although plasma glucose and plasma insulin were unchanged. When islets from untreated mice were exposed to cyclosporin A (2 mg/l) in vitro, no effect was seen in the first hour. After 24 h, cyclosporin A had significantly decreased the islet content of insulin. Post-culture microperifusion showed that cyclosporin A for 24 or 72 h inhibited the insulin secretory responsiveness. Verapamil in vivo (0.4 mg/kg body wt per day) or in vitro (37.5 μg/l) did not modify these effects. Verapamil at 25 mg/l suppressed the release of insulin but afforded no obvious protection against cyclosporin A during culture. The beneficial action of verapamil on islets transplanted to the kidney may reflect renal events rather than a primary interaction of drugs in the islets.

Endocrinology, 1968

Abstract Chemical micromethods were used for studying the effect of glucagon on the adenosine mon... more Abstract Chemical micromethods were used for studying the effect of glucagon on the adenosine monophosphate-and adenosine triphosphate-splitting enzyme activities in the endocrine pancreas from rats. Glucagon administration for 8 days stimulated the ...

Diabetologia, 1980

Islets from diabetic C57BL/KsJ db/db mice and normal C57BL/KsJ + / + mice were loaded with 86Rb+ ... more Islets from diabetic C57BL/KsJ db/db mice and normal C57BL/KsJ + / + mice were loaded with 86Rb+ and micro-perifused with nonradioactive medium for 25 min. The appearance of 86Rb+ in the effluent could be described as the sum of two exponential functions with different proportionality constants. The rapid efflux component may have represented washout from the extracellular space, and had about the same proportionality constant in normal and diabetic mice. The slow efflux component probably reflected efflux across the islet cell plasma membranes. At 3 mmol/l D-glucose in the medium, the slow efflux was significantly retarded in diabetic as compared with normal mice. In normal mice, but not in diabetics, 20 mmol/1 D-glucose inhibited the slow efflux component. It is concluded that the basal K + permeability is decreased in KsJ db/db mouse islet cells, and that this abnormality may explain their persistant depolarization at low glucose concentrations.

Diabetologia, 1978

Fluxes of 86Rb+ and hydrolysis of p-nitrophenyl phosphate were measured in collagenaseisolated is... more Fluxes of 86Rb+ and hydrolysis of p-nitrophenyl phosphate were measured in collagenaseisolated islets of diabetic C57BL/KsJ-db/db-mice and normal controls (C57BL/KsJ-+/+). Both types of islets accumulated Rb + avidly, as originally reported for hand-dissected islets of non-inbred ob/ ob-mice. KsJ-db/db-mouse islets showed enhanced accumulation of Rb + and normal acitivity of K +activated nitrophenyl phosphatase. D-glucose, 20 mmol/l, inhibited Rb + efflux in normal islets but not in those from KsJ-db/db-mice. The glucose insensitivity of Rb + efflux was observed in young animals, which exhibit glucose-induced insulin release, as well as in old animals, which do not secrete insulin in response to glucose. The anomalous regulation of Rb + efflux already present in young animals may bear on the liability of KsJ-db/db-mouse B-cells to develop defective control of membrane potential, an abnormal metabolism of cyclic AMP, and a marked failure of insulin secretory capacity.