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Biomedical subjects

M Hammar

Publications and source records attributed to M Hammar.

At least 73 records · Page 4Linked to original sources
PubMed1996

Nucleator-dependent intercellular assembly of adhesive curli organelles in Escherichia coli.

Bacterial adhesion to other bacteria, to eukaryotic cells, and to extracellular matrix proteins is frequently mediated by cell surface-associated polymers (fimbriae) consisting of one or more subunit proteins. We have found that polymerization of curlin to fimbriae-like structures (curli) on the surface of Escherichia coli markedly differs from the prevailing model for fimbrial assembly in that it occurs extracellularly through a self-assembly process depending on a specific nucleator protein. The cell surface-bound nucleator primes the polymerization of curlin secreted by the nucleator-presenting cell or by adjacent cells. The addition of monomers to the growing filament seems to be driven by mass action and guided only by the diffusion gradient between the source of secreted monomer and the surface of monomer condensation.

Amino Acid Sequence↗
PubMed1996

Climacteric symptoms in a postmenopausal Czech population.

OBJECTIVES: To assess the prevalence of climacteric symptoms and the use of hormone replacement therapy in a former eastern European country. All 55-, 57-, 59- and 61-year-old women in Kladno in the Czech Republic were asked to participate in the study. METHOD: In 1993, 1505 women in Kladno of the Czech Republic were sent a postal questionnaire concerning age at menopause and their climacteric symptoms. RESULTS: Answers were received from 799 women (53%); 98% were postmenopausal. The median age at spontaneous menopause was 50 years, 49.5 years among women smoking at least 5 cigarettes/day and 51.0 years among non-smokers (P < 0.05). About every fifth woman smoked. Totally 22% of the women had undergone hysterectomy and/or oophorectomy and 3% had been treated for a gynaecological malignancy. The majority of the women (58%) reported ongoing vasomotor symptoms; half of them had moderate to severe vasomotor symptoms. In all, 79% of the women reported ever having vasomotor symptoms. Only 3% of the women had ever tried hormone replacement therapy (HRT) and one woman had current treatment. Dysuria was reported by 22% and 4% had recurrent urinary tract infections; 70% of the women had a partner and 50% were sexually active. Reasons for not being sexually active were mostly lack of a partner, loss of sexual desire or partner's disease or impotence. CONCLUSION: Climacteric symptoms including vasomotor and urogenital symptoms had the same prevalence in the Czech Republic as previously reported in other Western Countries. Only a few women had tried HRT. Smokers had a slightly earlier menopause.

Aged↗
PubMed1996

Hormone replacement therapy and previous use of oral contraceptives among Swedish women.

OBJECTIVES: To assess the current and previous use of hormone replacement therapy (HRT) and alternative remedies in a postmenopausal population and to relate HRT use to previous use of oral contraceptives. MATERIAL AND METHODS: All 1323 women living in Linköping of 55 or 56 years old during 1995 were sent a questionnaire asking for data with relation to health and climacteric symptoms as well as to previous and current use of HRT, oral contraceptives and alternative remedies. RESULTS: Current use of HRT was more common among women who previously used oral contraceptives (41.3%) than among women who had never used oral contraceptives (23.1%). HRT users were also more often physically active, had undergone hysterectomy and had lighter occupation than non-users. Of all women 35% were current users of HRT, half of them for at least 2 years, whereas only 5% had tried HRT and abandoned therapy. Alternative remedies were used by 5% of the women as therapy for climacteric complaints, and about four times as many women had tried such therapy but abandoned it. The only characteristic about use of alternative medicines was that they were used less often by women who had been hysterectomized. No women treated for breast cancer used HRT and only few of them used alternative remedies. CONCLUSIONS: The prevalence of HRT use, as well as compliance, was high. Previous use of oral contraceptives probably affected the attitude towards using HRT.

Climacteric↗
PubMed1995

The effect of oral magnesium substitution on pregnancy-induced leg cramps.

OBJECTIVE: Our purpose was to determine whether women with pregnancy-related leg cramps would benefit from oral magnesium supplementation. STUDY DESIGN: Seventy-three women with pregnancy-related leg cramps were interviewed about their symptoms in a prospective, double-blind, randomized trial. Initial serum magnesium levels and diurnal magnesium excretion was determined in 50% of the patients. Oral magnesium or placebo was given for 3 weeks, after which new interviews and laboratory analyses were performed. RESULTS: Serum magnesium levels in these patients were at or below the lower reference limit, as is also often the case in healthy pregnant patients. Oral magnesium substitution decreased leg cramp distress (p < 0.05 compared with the placebo group, p < 0.001 compared with initial complaints), but did not significantly increase serum magnesium levels, excess magnesium being excreted as measured by an increase in urinary magnesium levels (p < 0.002). CONCLUSION: Oral magnesium supplementation seems to be a valuable therapeutic tool in the treatment of pregnancy-related leg cramps.

Administration, Oral↗
PubMed1995

The climacteric among South-American women, who immigrated to Sweden and age-matched Swedish women.

Forty-nine immigrated South-American (SA) and 48 Swedish women, aged 42-67 years, were studied in a comparative semi-structured interview survey, concerning the climacteric and its treatment. The mean age at natural menopause was 47 for the South-American women and 50 for the Swedish women. The prevalence of moderate to severe vasomotor symptoms at the time of the survey did not differ significantly between the non-treated, non-operated, postmenopausal South-American and Swedish women (36% and 21%; N.S.). One reason for the trend towards a higher prevalence among South-American women could be that a greater number of Swedish women used hormone replacement treatment compared to South-American women (11 vs. 4). The general attitude to hormone replacement therapy was more positive among South-American women, although they did not use hormone therapy, as could be expected from their symptoms. These results are probably an illustration of the difficulties in getting access to treatment for the immigrated SA women.

Adult↗
PubMed1995

Transdermal hormonal replacement therapy with transdermal progestin every second month.

OBJECTIVES: Unopposed estrogen therapy may induce endometrial hyperplasia. To protect the endometrium, estrogen replacement therapy should be combined with a progestin in menopausal women with an intact uterus. The aim of this open non-comparative study was to evaluate the effects on bleeding control and endometrium of 'spacing-out' the 14-day progestin therapy to every second month during transdermal combined hormonal replacement therapy. METHODS: Sixty-eight healthy women, previously treated with sequential combined transdermal hormonal replacement therapy every month for 3 years, were treated for the following 2 years in cycles with 6 weeks of transdermal estradiol 50 micrograms/daily (Estraderm, Ciba-Geigy), followed by 2 weeks of combined norethisterone acetate 0.25 mg/day and 50 micrograms estradiol per day. RESULTS: Annual endometrial biopsies diagnosed hyperplasia in one woman during the second year whereas most biopsies showed a secretory endometrium. Vaginal ultrasound showed no correlation to either bleeding-pattern or histopathological diagnosis. Most women had a regular bleeding-pattern. CONCLUSIONS: Transdermal progestin every second month might be an alternative to regular monthly sequential hormonal replacement therapy.

Administration, Cutaneous↗
PubMed1995

Expression of two csg operons is required for production of fibronectin- and congo red-binding curli polymers in Escherichia coli K-12.

Two divergently transcribed operons in Escherichia coli required for the expression of fibronectin- and Congo red-binding curli polymers were identified and characterized by transposon mutagenesis, sequencing and transcriptional analyses, as well as for their ability to produce the curli subunit protein. The csgBA operon encodes CsgA, the major subunit protein of the fibre, and CsgB, a protein with sequence homology to CsgA. A non-polar csgB mutant is unaffected in its production of CsgA, but the subunit protein is not assembled into insoluble fibre polymers. A third open reading frame, orfC, positioned downstream of csgA may affect some functional property of curli since an insertion in this putative gene abolishes the autoagglutinating ability typical of curliated cells without affecting the production of the fibre. The promoter for the oppositely transcribed csgDEFG operon was identified by primer extension and shown, like the csgBA promoter, to be dependent upon the alternate stationary phase-specific sigma factor sigma s in wild-type cells, but not in mutants lacking the nucleoid associated protein H-NS. Insertions in csgD abolish completely trancription from the csgBA promoter. Therefore, any regulatory effect on the csgBA promoter might be secondary to events controlling the csgDEFG promoter and/or activation of CsgD. Insertions in csgE, csgF and csgG abolish curli formation but allow CsgA expression suggesting that one or more of these gene products are involved in secretion/assembly of the CsgA subunit protein. No amino acid sequence homologies were found between the CsgE, CsgF and CsgG proteins and secretion/assembly proteins for other known bacterial fibres, suggesting that the formation of curli follows a novel pathway.

Bacterial Proteins↗
PubMed1995

Oral contraceptives and low back pain. Attitudes among physicians, midwives and physiotherapists.

BACKGROUND: Only few indications have appeared in the literature concerning a possible relationship between the use of oral contraceptives and low back pain. In our daily work we often meet women who have been recommended to abandon their use of oral contraceptives depending on coexisting low back pain. In order to assess the opinions of a possible relationship between oral contraceptives and low back pain this study was undertaken. METHODS: A validated questionnaire was sent out to physicians, physiotherapists and midwives dealing with either contraceptive counselling or low back pain. A modified questionnaire was sent to medical- and physiotherapist students to assess whether the opinions were a result of the education or the working experience. RESULTS: A total of 225 questionnaires were sent out and 206 (91%) were returned. Sixteen percent thought there was a relationship between the use of oral contraceptives and risk of low back pain. Thirty percent had seen patients with low back pain that was interpreted as being affected by use of oral contraceptives. Twenty-five percent recommended at least some patients with low back pain to change their contraceptive method. Among the students there was a difference in opinion between the first and the last year students indicating that their opinions had been influenced by their education. CONCLUSIONS: Evidently many professionals dealing with oral contraceptives and low back pain believe that there is a relationship between oral contraceptives and low back pain, despite the lack of scientific evidence. These recommendations might influence the contraceptive safety for the individual woman and the possible relationship between use of oral contraceptives and low back pain should therefore be more thoroughly investigated before general recommendations are given.

Adolescent↗
PubMed1994

[Acupuncture against climacteric disorders? Lower number of symptoms after menopause].

Vasomotor symptoms are very common among perimenopausal women, but also among orchidectomized men. The cause of the symptoms is not the low steroid concentrations per se, but probably changes in central neuropeptide activity. Twenty-four healthy women with natural menopause, suffering from hot flushes, were included in the study and randomly assigned to either of two groups, one group received treatment with electrostimulated acupuncture (EA), the other with superficial needle position (SNP) acupuncture. Treatment was given for totally of eight weeks, twice a week during the first two weeks, and then once a week for the remaining six weeks. As recorded in logbooks kept by the participants, the frequency of flushes decreased significantly by more than 50 per cent in both groups, and remained decreased in the EA group, whereas in the SNP group it increased slightly again over the three months after treatment. Values for the Kupperman Index decreased in both groups during treatment, changes still evident at three-month follow-up, whereas the self-rated general climacteric symptoms (VAS) decreased significantly in the EA group only. The PGWB (Psychological General Well-Being) index did not change significantly in either group during treatment.

Acupuncture Therapy↗