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E Nielsen

Publications and source records attributed to E Nielsen.

At least 55 records · Page 3Linked to original sources
PubMed1991

Cysteine residue periodicity is a conserved structural feature of variable surface proteins from Paramecium tetraurelia.

The DNA sequences of the entire coding regions of the A and C type variable surface protein genes from Paramecium tetraurelia, stock 51 have been determined. The 8151 nucleotide open reading frame of the A gene contains several tandem repeats of 210 nucleotides within the central portion of the molecule as well as a periodic structure defined by cysteine residues. The 6699 nucleotide open reading frame of the C gene does not contain any identifiable tandem repeats or internal similarity but maintains a periodicity based on the cysteine residue spacing. The deduced amino acid sequences encoded by the two genes are most similar within the 600 amino-terminal and 600 carboxyl-terminal amino acid residues, the central portions show only limited sequence similarity. We conclude that internal repeats are not a conserved feature of variable surface proteins in Paramecium and discuss the possible importance of the regular pattern of cysteine residues.

Amino Acid Sequence↗
PubMed1991

Chromogranin-B, a putative precursor of eight novel rat glucagonoma peptides through processing at mono-, di-, or tribasic residues.

Chromogranin-B (CgB), a secretory granule protein, is normally synthesized in a variety of neuroendocrine tissues, including the pancreatic islet alpha-cells. We have demonstrated that rat CgB is expressed and extensively processed by limited proteolysis in a transplantable glucagonoma tumor line. Eight peptides (fragments 1-8) purified by HPLC from acidic tumor extracts were partially sequenced and showed homology to CgB amino acid sequences deduced from rat, mouse, and human cDNA. Similar peptides were not found in insulinomas of common origin. The determined amino acid sequence represents approximately 35% of the rat precursor CgB. Ten of a total of 231 sequenced residues deviated from the published rat cDNA sequence. The differences were clustered in 3 fragments, suggesting allelic polymorphism. Five of the 8 peptides could be derived from the precursor by processing at paired basic amino acids, but processing N-terminally at a single basic residue was also seen. One peptide equivalent to the previously reported C-terminal CgB (CCB) is released by processing at a tribasic segment. Fragment 1 containing the N-terminal sequence Ala-Pro-Val-Asp represents the actual N-terminus of CgB after removal of the putative signal peptide sequence. All processing sites used in glucagonoma tissue to derive the 8 isolated fragments were conserved between murine and human CgB. At least 3 dibasic sites present in rat, but not human, CgB sequence were actually not used. A previously reported CgB-derived pituitary peptide, GAWK, was further processed at a conserved internal dibasic site to yield fragment 6, indicating alternative processing in different tissues. The small undecapeptide, fragment 7, is 100% conserved among murine and human CgB and, thus, may have an important biological function. We conclude that CgB is extensively processed in glucagonoma tissue by limited proteolysis as prohormones at conserved basic residues. The proglucagon-converting enzymes present in transformed alpha-cells are likely candidates to be involved in tissue-specific CgB processing. Distinct biological activities of any of the CgB-derived fragments remain to be identified.

Amino Acid Sequence↗
PubMed1990

Protein HMG-17 is hyper-expressed in rat glucagonoma. Single-step isolation and sequencing.

High-mobility-group protein 17 (HMG-17) was identified by reversed-phase high-performance liquid chromatography analysis as a major component in acidic extracts of transplantable rat glucagonoma tissue but not in insulinoma tissue of similar origin. The peptide was purified in a single step and the entire sequence of 89 amino acids was determined. Rat HMG-17 has a molecular mass of 9238 Da and shows strong similarity to human, bovine (94.4%) and chicken (88.8%) HMG-17. Six of the seven residues which vary among the mammalian sequences are located within a short segment (positions 64-83) present in the acidic, non-DNA-binding C-terminal part of HMG-17. This region shows least similarity to the otherwise related proteins HMG-14 and H6 (a trout HMG protein). Interestingly, four of the six variable positions are Asp in rat HMG-17 which results in an overall net increase in the negative charge of the C-terminal region. The nature of selective hyper-expression of HMG-17 in glucagon but not in insulin-producing tumor tissue remains to be clarified.

Adenoma, Islet Cell↗
PubMed1990

Histologic changes and silicone concentrations in human breast tissue surrounding silicone breast prostheses.

Using a previously developed method for quantitative measurements of silicone concentrations in breast tissue, material from 86 biopsies from 67 breasts in 55 patients who had silicone implants was examined. In the 49 breast with unruptured prostheses, there was a positive relation between the concentrations and inflammatory reactions, the only exception being the amount of plasma cells, which showed a negative relation. It is concluded that silicone prostheses provoke an inflammatory response not only because they act as foreign bodies, but also because of silicone seepage through intact membranes.

Breast↗
PubMed1990

Cat scratch disease and glomerulonephritis.

Cat scratch disease is a generally benign, self-limited disease characterized by fever and regional lymphadenitis. Systemic complications are rare and most frequently affect the central nervous system, bone, liver or spleen. We report the first case of glomerulonephritis associated with cat scratch disease which resolved spontaneously concurrent with the resolution of lymphadenitis and constitutional symptoms. Immunopathologic and ultrastructural studies suggest a form of immune-mediated postinfectious glomerulonephritis.

Adolescent↗
PubMed1990

The effect of a soluble dietary fibre supplement on 24-hour energy expenditure during a standardized physical activity programme.

Twenty-four hour energy expenditure during a standard physical activity programme was investigated in 19 healthy volunteers in a randomized, double-blind, cross-over design, after supplementation with a soluble dietary fibre amounting 7 g/day for 2 weeks. Energy intake and food fibre intake were kept constant during the treatment period. Twenty-four hour energy expenditure decreased insignificantly during fibre treatment (1.3 +/- 1.7 per cent). The dietary fibre supplement also had no significant effect on body weight, faecal energy loss or heart rate. Systolic blood pressure was insignificantly reduced during both placebo and fibre treatment (P = 0.09). There was, however, no difference between the groups after treatment.

Adolescent↗
PubMed1990

The effect of long-term dexfenfluramine treatment on 24-hour energy expenditure in man. A double-blind placebo controlled study.

In order to investigate the effect of long-term treatment with dexfenfluramine (dF) on 24-hour energy expenditure (EE), 10 obese females were studied in a double-blind design. Shortly before and 4 weeks after cessation of a 13 months treatment period with either dF (30 mg/day) or placebo (PL) the 24-hour EE was measured. The measurements were performed using a 24 m3 direct heat sink calorimeter with continuous real time measurements of evaporative and sensible heat losses. The patients performed a standardized program of exercise, rest and meals. The measurements were performed at 24 degrees C and at a humidity between 3 and 11 g/m3. Discontinuation of dF treatment did not change energy expenditure significantly from placebo, neither when expressed in kJ/kg lean body mass nor in kJ/kg body weight. After cessation of treatment total 24-hour EE decreased likewise nonsignificantly by 2.9 percent in the dF group and by 4.0 percent in the PL group. EE measured over 24 hours was subdivided into day and night periods and into resting energy expenditure as well as a measurement of the heat losses over a period of 3 hours after a meal. This subdivision of the EE showed similar nonsignificant differences. The conclusion is therefore that dF possesses no significant thermogenic effect during long-term administration in human obese subjects.

Adult↗
PubMed1990

Changes in energy expenditure of light physical activity during a 10 day period at 34 degrees C environmental temperature.

The energy expenditure of a 2 h programme of light activity was observed daily in 8 young men after a change in habitual environmental indoor temperature of 20-24 degrees C to 34 degrees C and an absolute humidity of 6-10 g/m3 during a 10 day period. No changes were observed with respect to the daily energy intake, body weight, rectal temperature and average skin temperature, but the energy expenditure showed a decrease of between 3 and 8 per cent. The observations support results of previous studies on acclimatization with respect to energy expenditure, and indicate that differences in energy expenditure due to habitual differences in environmental temperature are small, presumably less than 5 per cent.

Adolescent↗
PubMed1990

Negligible effects of previous moderate physical activity and changes in environmental temperature on whole body electrical impedance.

Several studies have shown that the predictive power of various linear combinations of anthropometric data (body weight, height, sex, age, etc.) to estimate fat free mass is improved after inclusion of measurements of electrical impedance (see eg Khaled et al., 1988). Published algorithms are based on measurements performed under fairly standardized conditions with the subjects at stationary conditions of rest, of environmental temperature and of body fluids. Use of the method under less standardized conditions raises the question of possible effects of deviations from these standard conditions. Hydration and dehydration by 1-2 l of fluid increased or decreased, respectively, the electrical resistance by about 14 per cent and the effects persisted for more than 1 h (Khaled et al., 1988). A change in environmental temperature by 21 degrees C from 35 degrees C to 14 degrees C (with almost constant relative humidity) during 90 min caused an increase in the resistance of about 9 per cent (Caton et al., 1988). The perturbations used in the studies quoted above are fairly drastic and not likely to occur under reasonably controlled field conditions. Therefore, we report here results of measurements of whole body electrical impedance before, during and after a period of 10 degrees C increased environmental temperature and before and after a 5-min period of light to moderate physical exercise.

Electric Conductivity↗
PubMed1988

The molecular cloning of the chromogranin A-like precursor of beta-granin and pancreastatin from the endocrine pancreas.

The cDNA encoding the precursor form of the chromogranin A-related proteins, beta-granin and pancreastatin, was obtained by immune screening of rat insulinoma and pancreatic islet cDNA libraries. The sequence was virtually identical to that of rat adrenal chromogranin A, suggesting that the different molecular forms of chromogranin A immunoreactivity found in adrenal medulla and endocrine pancreas are related to differences in post-translational proteolytic processing. The rat chromogranin A, unlike its bovine and human counterparts, contained a 20-residue glutamine sequence inserted within the N-terminal beta-granin sequence. Although the encoding CA(G/A) repeat recurs frequently in the rat genome, the rat chromogranin A molecule appears to be the product of a single gene and mRNA transcript.

Amino Acid Sequence↗
PubMed1988

Isolation and characterization of a 14-kDa albumin-binding fragment of streptococcal protein G.

Protein G, a streptococcal cell wall protein, has separate binding sites for human albumin and IgG. Streptococci expressing protein G were treated with the bacteriolytic agent mutanolysin. Several IgG- and human serum albumin (HSA)-binding peptides were identified in the material thus solubilized and one of these, a 14-kDa peptide, was found to bind HSA but not IgG in Western blot experiments. This molecule was purified by affinity chromatography on Sepharose coupled with HSA followed by gel filtration on Sepharose 6B and a final affinity chromatography on IgG-Sepharose, by which low Mr W(15 to 20 kDa)IgG-binding peptides were removed. In different binding experiments the purified 14-kDa peptide bound exclusively HSA and the equilibrium constant between the peptide and HSA was determined to be 3.4 X 10(8) M-1. The relation between the 14-kDa molecule and protein G was studied by analyzing the N-terminal amino acid sequence of the peptide and comparing it with the previously determined protein G sequence. The 40 N-terminal amino acids were found to be identical with an amino acid sequence starting at position 62 in the protein G molecule. These and previous data enabled us to locate the albumin binding to the repetitively arranged domains in the N-terminal half of the protein G molecule.

Bacterial Proteins↗
PubMed1988

Television as a patient education tool: a review of its effectiveness.

Thirty-three studies of the use of television as a patient-education process are reviewed. While there are many different conditions addressed by the studies and many studies have methodological problems there are consistencies in the results that suggest how this medium has a role to play. Eleven studies randomized subjects and had a control group. All but one reported achieving their objective of knowledge gain, skill training, or behavior change. Video presentation alone was as effective as any other presentation method and was more effective than only written information. Recommendations for the use of television for patient education are included.

Behavior Therapy↗
PubMed1988

Effect of 12 weeks' light-moderate underfeeding on 24-hour energy expenditure in normal male and female subjects.

The effect of 12 weeks' light-moderate underfeeding on the 24-h energy expenditure of a fixed physical activity programme was studied in six male and six female subjects. During a control period of 2 weeks, measurements were made of 24-h energy expenditure by direct calorimetry, the lean and fat body masses and the subjects' habitual energy intakes. The average body weight was 107 per cent of ideal, and did not change significantly during the control period. The subjects were asked to continue to record their daily food intake while reducing it by 25 per cent and to continue their daily activity habits during a period of 12 weeks. The mean change in body weight was -2.9 kg with an average change in body energy content of -66 MJ. The 24-h energy expenditure was measured three times during the period, ie, after 4, 8 and 12 weeks from the start of the decreased energy intake, and found to be practically the same as the control value, ie, with average differences (s.d.) of -0.2(3.9), -0.8(5.7) and +0.6(4.2) per cent from the control value. In the six subjects who had the largest loss of body weight, this was found to be 5.0 kg, and the mean differences (s.d.) in energy expenditure were found to be -1.0(3.4), 0.0(5.6) and -0.6(3.9) per cent, respectively, from the control value. A significant part of the between-subjects variation in the differences from the control value is due to random measurement error and it is concluded that a loss of body energy content of the magnitude reported here, and due mainly to a reduced food intake, does not result in a significant increase in the efficiency of energy conversion, ie, in metabolic adaptation.

Adult↗