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Biomedical subjects

J Aström

Publications and source records attributed to J Aström.

At least 19 recordsLinked to original sources
PubMed2003

Changes in bronchoalveolar lavage fluid proteins in sarcoidosis: a proteomics approach.

In sarcoidosis, an inflammatory lung disease, the protein profile of bronchoalveolar lavage fluid (BALF) is altered. To study the BALF protein pattern changes in sarcoidosis, samples from six patients and four healthy individuals were analysed by two-dimensional polyacrylamide gel electrophoresis. A comparison of the protein-spot patterns showed a significantly higher number of protein spots in the pH range 5.5-6.7 in patients compared to controls (472 versus 384). Furthermore, the number of protein spots in the patients were significantly decreased in the acidic pH range 4.5-5.5 (399 versus 518). Measurement of the optical density in the gels showed varying expression levels for several protein spots. Seventeen of the altered protein spots were identified, of which seven have previously not been reported for BALF. Many of these are nonplasma proteins involved in the inflammatory and oxidant-antioxidant processes. In conclusion, the bronchoalveolar lavage fluid protein content is altered in sarcoidosis patients, especially for proteins that are not derived from plasma. The described proteomics approach will in the future be used to asses overall changes in the protein content associated with sarcoidosis and may offer the possibility of identifying disease-specific proteins.

Adult↗
PubMed2001

Detection and identification of human bronchoalveolar lavage proteins using narrow-range immobilized pH gradient DryStrip and the paper bridge sample application method.

The use of two-dimensional gel electrophoresis as a tool for the investigation of human bronchoalveolar lavage fluid (BALF) has been hampered by technical difficulties. In the last decade attempts have been made to establish a two-dimensional (2-D) protein map of BALF samples, resulting in the identification of a number of proteins present in BALF. In this study, we report an improved sample handling and separation protocol for investigation of human BALF proteins. The sample has been analyzed by employing a number of strategies, including the 'paper bridge' sample application method in combination with narrow range immobilized pH gradient (IPG) DryStrips, followed by comparison to the corresponding plasma map. Using peptide mass fingerprinting, we have identified 49 proteins in the narrow pH range 4.5-5.2 from an individual healthy BALF sample. Furthermore, we identified 17 BALF proteins, not detected in plasma. Twelve of these proteins have, to our knowledge, not previously been described in the BALF 2-D map. The mapping of BALF proteins with inclusion of those at low concentration increases the possibility to subsequently screen patient material for disease markers.

Bronchoalveolar Lavage Fluid↗
PubMed2000

An immobiline DryStrip application method enabling high-capacity two-dimensional gel electrophoresis.

In the field of proteomics the need to detect low-abundance cellular components, such as regulatory proteins, is of critical importance. Two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) is one of the most commonly used separation tools for these biological investigations. In this paper we report an alternative micropreparative 2-D PAGE sample application method, called the "paper bridge loading" method. This method makes it possible to apply a larger sample volume to commercially available immobilized pH gradient (IPG) strips. The Vh products required for focusing are only marginally longer than those used in analytical experiments. The method was compared to traditional cup loading and in-gel rehydration. With 18 cm long narrow-range Immobiline DryStrip pH 4.5-5.5, the "paper bridge" method allowed the application of 10 mg human plasma proteins compared to 3 mg with traditional loading methods. The corresponding figures using Escherichia coli sample was found to be 6 mg and less than 2 mg, respectively. The paper bridge method also showed the best results in terms of spot resolution and separation of high molecular weight proteins.

Acrylamides↗
PubMed1998

Modifications of the 5' cap of mRNAs during Xenopus oocyte maturation: independence from changes in poly(A) length and impact on translation.

The translation of specific maternal mRNAs is regulated during early development. For some mRNAs, an increase in translational activity is correlated with cytoplasmic extension of their poly(A) tails; for others, translational inactivation is correlated with removal of their poly(A) tails. Recent results in several systems suggest that events at the 3' end of the mRNA can affect the state of the 5' cap structure, m7G(5')ppp(5')G. We focus here on the potential role of cap modifications on translation during early development and on the question of whether any such modifications are dependent on cytoplasmic poly(A) addition or removal. To do so, we injected synthetic RNAs into Xenopus oocytes and examined their cap structures and translational activities during meiotic maturation. We draw four main conclusions. First, the activity of a cytoplasmic guanine-7-methyltransferase increases during oocyte maturation and stimulates translation of an injected mRNA bearing a nonmethylated GpppG cap. The importance of the cap for translation in oocytes is corroborated by the sensitivity of protein synthesis to cap analogs and by the inefficient translation of mRNAs bearing nonphysiologically capped 5' termini. Second, deadenylation during oocyte maturation does not cause decapping, in contrast to deadenylation-triggered decapping in Saccharomyces cerevisiae. Third, the poly(A) tail and the N-7 methyl group of the cap stimulate translation synergistically during oocyte maturation. Fourth, cap ribose methylation of certain mRNAs is very inefficient and is not required for their translational recruitment by poly(A). These results demonstrate that polyadenylation can cause translational recruitment independent of ribose methylation. We propose that polyadenylation enhances translation through at least two mechanisms that are distinguished by their dependence on ribose modification.

Animals↗
PubMed1996

Greeting behaviour and psychogenic need: interviews on experiences of therapists, clergymen, and car salesmen.

Interviews of 47 Swedish subjects, therapists, clergymen, and car salesmen were used to investigate relationships between 22 greeting behaviours and 12 psychogenic needs mainly drawn from the Cecarec-Marke Personality Schedule. Analysis showed that most of the subjects agreed about the personality characteristics of greeting behaviours, especially regarding the dimensions of introversion and extraversion. The results confirm those from earlier studies that some greeting behaviours are potentially valid in assessing personality.

Adult↗
PubMed1994

Multiple forms of poly(A) polymerases in human cells.

We have cloned human poly(A) polymerase (PAP) mRNA as cDNA in Escherichia coli. The primary structure of the mRNA was determined and compared to the bovine PAP mRNA sequence. The two sequences were 97% identical at the nucleotide level, which translated into 99% similarity at the amino acid level. Polypeptides representing recombinant PAP were expressed in E. coli, purified, and used as antigens to generate monoclonal antibodies. Western blot analysis using these monoclonal antibodies as probes revealed three PAPs, having estimated molecular masses of 90, 100, and 106 kDa in HeLa cell extracts. Fractionation of HeLa cells showed that the 90-kDa polypeptide was nuclear while the 100- and 106-kDa species were present in both nuclear and cytoplasmic fractions. The 106-kDa PAP was most likely a phosphorylated derivative of the 100-kDa species. PAP activity was recovered in vitro by using purified recombinant human PAP. Subsequent mutational analysis revealed that both the N- and C-terminal regions of PAP were important for activity and suggested that cleavage and polyadenylylation specificity factor (CPSF) interacted with the C-terminal region of PAP. Interestingly, tentative phosphorylation sites have been identified in this region, suggesting that phosphorylation/dephosphorylation may regulate the interaction between the two polyadenylylation factors PAP and CPSF.

Animals↗
PubMed1993

Handshaking, personality, and psychopathology in psychiatric patients, a reliability and correlational study.

A study of 29 psychiatric inpatients was performed to investigate the relation of handshaking variables (anatomical and physiological variables) with demographic data, personality traits, psychosocial functioning, and clinical diagnoses. Two psychologists rated patients' handshaking independently of each other according to four variables on an ordinal scale of five steps. The interrater reliability was satisfactory. Analysis showed that the handshaking procedure may in fact give some information about the personality make-up of the patients, most clearly through the relationship between low temperature and humidity of the palmar skin and social introversion, depression, and tendency towards symptom enhancement mainly in women. The handshaking procedure did not seem informative about psychosocial functioning and clinical diagnoses.

Adult↗
PubMed1993

Attitudes towards and observations of nonverbal communication in a psychotherapeutic greeting situation: III. An interview study of outpatients.

An interview study of 50 Swedish nonpsychotic outpatients treated by some kind of psychotherapy was performed to investigate their attitudes towards and observations of nonverbal communication in a greeting situation according to the Questionnaire on Nonverbal Communication (psychotherapy patients' version) in relation to background factors such as gender, age, education, and profession, interest in psychological matters, "reading articles and books in psychology," duration of professional help for psychological troubles, number of occasions waiting for a new therapist, and number of therapeutic sessions before the interview. The greeting situation was the first time a patient and a therapist met in a waiting room. Test-retest reliability of the questionnaire was larger for items about observation of nonverbal communication than for those about attitudes. Face communication (eye contact and smile) was considered by the subjects to constitute the most important nonverbal communication in the greeting process. The importance of the face in communication was stressed when the patient believed that such communication corresponded to more than 50% of the total communication in general, was female, was elderly, or reported special interest in nonverbal communication in the greeting situation. Some effects of bias were discussed. The analyses also showed a considerable consciousness and observation in the greeting situation by many psychotherapeutic outpatients.

Adult↗
PubMed1992

Properties of a HeLa cell 3' exonuclease specific for degrading poly(A) tails of mammalian mRNA.

A HeLa cell 3'-exonuclease with properties of a mammalian mRNA poly(A) tail-removing enzyme has been characterized. The exonuclease shows high specificity for the poly(A) tail, and it is single strand-specific and requires a 3'-hydroxyl group for its activity. During degradation 5'-AMP is liberated as a product, and a 3'-OH group is left on the last adenosine residue of the remaining poly(A) tail. The activity is inhibited by 5'-AMP and can be competed by poly(A)-containing mRNA or poly(A). Based on these findings we propose a reaction pathway for poly(A) tail removal catalyzed by the HeLa cell poly(A) tail-specific 3' exonuclease.

Base Sequence↗
PubMed1992

Reduced risk of hip fracture in the mothers of patients with osteoarthritis of the hip.

In a population-based study we identified a cohort of 282 women, whose children had been treated for osteoarthritis of the hip. The incidence of hip fracture in these mothers was 0.54 (95% CI 0.35 to 0.83) of that in the whole population of their age and sex. This finding could be explained by a genetic factor for increased rigidity of subchondral bone, making osteoarthritis more likely and osteoporosis less likely.

Age Factors↗
PubMed1992

Psychotherapists' attitudes towards and observations of nonverbal communication in a greeting situation: II. Relationships to background variables.

An interview study of 79 Swedish psychotherapists was performed to investigate their attitudes towards and observation of nonverbal communication in a reference situation in relation to background factors such as gender, length of professional experience, and theoretical approach. The greeting situation, i.e., the first time a therapist and patient meet in a waiting-room, was chosen as the reference situation. Face communication in that greeting situation was significantly less achieved by male psychotherapists with relatively short experience than by female therapists. However, this sex difference was not significant among therapists whose psychotherapeutic experience was longer than 13 years. Attaching great importance to nonverbal communication in psychotherapy was related to an intention to be well-kept and to perform correctly in front of the patient, to establish direct communication in the greeting situation, and to background factors such as frequent work in psychotherapy and an eclectic psychotherapeutic approach.

Attitude of Health Personnel↗
PubMed1991

A simple procedure for isolation of eukaryotic mRNA polyadenylation factors.

We have devised a simple chromatographic procedure which isolates five polyadenylation factors that are required for polyadenylation of eukaryotic mRNA. The factors were separated from each other by fractionation of HeLa cell nuclear extract in two consecutive chromatographic steps. RNA cleavage at the L3 polyadenylation site of human adenovirus 2 required at least four factors. Addition of adenosine residues required only two of these factors. The fractionation procedure separates two components that are both likely to be poly(A) polymerases. The candidate poly(A) polymerases were interchangeable and participated during both RNA cleavage and adenosine addition. They were discriminated from each other by chromatographic properties, heat sensitivity and divalent cation requirement. We have compared our data with published information and have been able to correlate the activities that we have isolated to previously identified polyadenylation factors. However, we have not been able to assign one of the candidate poly(A) polymerases to a previously identified poly(A) polymerase. This simple fractionation procedure can be used for generating an in vitro reconstituted system for polyadenylation within a short period of time.

Cell Nucleus↗
PubMed1991

In vitro deadenylation of mammalian mRNA by a HeLa cell 3' exonuclease.

We have identified a 3' exonuclease in HeLa cell extracts which deadenylates mammalian mRNA and leaves the mRNA body intact after poly(A) removal. Only homopolymeric adenosine tails located at the 3' end were efficiently removed by the exonuclease. The poly(A) removing activity did not require any specific sequences in the mRNA body either for poly(A) removal or for accumulation of the deadenylated mRNA. We conclude that the poly(A) removing activity is a 3' exonuclease since (i) reaction intermediates gradually lose the poly(A) tail, (ii) degradation is prevented by the presence of a cordycepin residue at the 3' end and (iii) RNAs having internally located poly(A) stretches are poor substrates for degradation. The possible involvement of the poly(A) removing enzyme in regulating mRNA translation and stability is discussed.

Base Sequence↗
PubMed1991

Psychotherapists' attitudes toward observations of nonverbal communication in a greeting situation: I. Psychometrics of a questionnaire.

A questionnaire was designed for the assessment of psychotherapists' attitudes toward nonverbal communication and their observation of it in a reference situation, i.e., the first time the therapist and the patient meet in a waiting room. The interrater reliability of the questionnaire was measured. Upon minor modifications, a final version of the questionnaire was completed, and the intrarater (test-retest) reliability, the discriminating capacity, and the homogeneity of the questionnaire were studied. The questionnaire has satisfactory psychometric qualities for use in research on nonverbal communication in psychotherapeutic greeting.

Attitude of Health Personnel↗
PubMed1988

Alignment and long-term clinical results of a semiconstrained knee prosthesis.

In knee arthroplasty, component malpositioning seems to be a fundamental cause for failure. The degree of malpositioning is important. To investigate this degree, 86 of 137 knee arthroplasties performed with the Townley semiconstrained bicondylar prosthesis were examined after a mean follow-up period of 6.5 years (range, 5.0-8.5 years). Five arthroplasties were excluded because of aseptic loosening, but none of these showed malalignment in postoperative roentgenograms. Clinical results and the patients' reports on deterioration of prosthetic function were correlated with positioning of the prosthetic components. Total alignment between 6 degrees of varus and 7 degrees of valgus was associated with good clinical results. Total alignment of more than 7 degrees of valgus, anterior tilting of the tibial component, or positioning of the femoral component in more than 12 degrees of valgus correlated with relatively poor clinical results.

Adult↗
PubMed1987

Physical activity in women sustaining fracture of the neck of the femur.

We have investigated the level of physical activity of 49 women between the ages of 15 and 45 years who sustained a fracture of the neck of the femur at between 60 and 70 years of age, and compared this with the level of activity reported by 49 control subjects without fracture, who were matched for age and social status. We found that the patients had been significantly less physically active than the controls, especially as regards household duties and professional working conditions.

Activities of Daily Living↗