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B Josefsson

Publications and source records attributed to B Josefsson.

17 recordsLinked to original sources
PubMed2001

Stereoselective determination of amino acids in beta-amyloid peptides and senile plaques.

A novel method for the determination of the enantiomeric composition of peptides is presented. In this paper, the focus has been on beta-amyloid peptides from deceased Alzheimer's disease patients. The peptides are hydrolyzed using mineral acid. The free amino acids are derivatized with the chiral reagent (+)- or (-)-1-(9-anthryl)-2-propyl chloroformate and subsequently separated using micellar electrokinetic chromatography (MEKC) and detected using laser-induced fluorescence (LIF) detection. The high separation efficiency of the MEKC-LIF system, yielding approximately 1 million theoretical plates/m for most amino acids, facilitates the simultaneous chiral determination of nine amino acids. The samples that have been analyzed were standard 1-40 beta-amyloid peptides, in vitro precipitated beta-amyloid fibrils, and human senile plaque samples.

Amino Acids↗
PubMed1998

Preovulatory changes of blood flow in different regions of the human follicle.

OBJECTIVE: To assess regional changes in ultrasound-derived indices of blood flow in the dominant human follicle after the plasma LH surge. DESIGN: A cross-sectional, prospective study. SETTING: Reproductive medicine unit at a university. PATIENT(S): Women attending an assisted conception clinic to determine the appropriate time to transfer previously frozen embryos during a natural cycle. INTERVENTION(S): Transvaginal ultrasonography with color Doppler imaging and pulsed Doppler spectral analysis was used to obtain indices of blood flow and velocity from vessels in the base, lateral part, and apex of the dominant follicle on days 10-12 (from day 1 of menses) and after the LH surge, but before rupture. Immunoassays were used to measure the blood concentrations of LH twice daily (at 8-10 A.M. and 4-6 P.M.) from cycle day 10. MAIN OUTCOME MEASURE(S): The pulsatility index (PI), resistance index (RI), peak systolic velocity (PSV), and time-averaged maximum velocity (TAMXV) in the uterine arteries and three regions of the dominant follicle (apical, lateral, and basal parts); follicular volume; the day and time of the onset of the LH surge (defined as first concentration of LH > 22 U/L) and the times of each scan. RESULT(S): Twenty-two women (aged 28-39 years) were studied and seven were scanned on days 10-12. A retrospective examination of the data from the remainder showed that eight were scanned < 20 hours after onset of the LH surge and seven were scanned > 20 hours after the onset of the LH surge. There was a significant increase in follicular volume after the LH surge. The PI was similar in vessels from the base (0.86 +/- 0.11; mean +/- SEM), lateral part (0.72 +/- 0.51) and apex (0.67 +/- 0.09) at cycle days 10-12 and then gradually decreased in the apex. There were similar changes in the RI. The PSV (mean +/- SEM; cm/s) was similar in vessels from the base (10.1 +/- 1.64), lateral side (8.2 +/- 1.43), and apex (9.2 +/- 1.91) in follicles of days 10-12. Within 20 hours of the onset of the LH surge, the PSV had increased in basal vessels (23.4 +/- 4.10), remained similar in lateral vessels (11.64 +/- 3.18), and was undetectable in apex vessels from six of eight follicles. Twenty hours after the LH surge, there was no pulsatile blood flow observed in the apical part of the follicle, but there was a sustained high PSV in the base (15.73 +/- 3.42) and lateral side (9.02 +/- 1.5). There were corresponding changes in the TAMXV. CONCLUSION(S): During the ovulatory process there are prominent changes in the regional blood flow of the follicle with a marked increase of the flow to the base of the follicle and a concomitant decrease of blood flow to the apex. These changes may be essential for the release of a mature oocyte.

Adult↗
PubMed1997

Enantiomeric determination of amino compounds with high sensitivity using the chiral reagents (+)- and (-)-1-(9-anthryl)-2-propyl chloroformate.

New chiral precolumn reagents, (+)- and (-)-1-(9-anthryl)-2-propyl chloroformate (APOC), are introduced for the chiral separation of amino acids and small peptides in capillary electrophoresis. Chiral separation of 17 amino acids and four small peptides as their diastereomeric 1-(9-anthryl)-2-propyl carbamate derivatives have been achieved by micellar electrokinetic chromatography. The detection limit for the derivatives is in the femtomole range with UV detection and in the attomole range with laser-induced fluorescence (LIF) detection. LIF detection was used to determine the enantiomeric excess of four APOC-derivatised peptides. The use of the new, anthracene-based reagents in conjunction with argon ion LIF makes enantiomeric determinations at ppm levels feasible. In this paper determinations below promille levels are performed without overloading the separation system.

Amino Acids↗
PubMed1997

Recombinant human follicle stimulating hormone (r-hFSH; Gonal-F) versus highly purified urinary FSH (Metrodin HP): results of a randomized comparative study in women undergoing assisted reproductive techniques.

A prospective, randomized, comparative, assessor-blind study was carried out in two centres to compare the efficacy and safety of recombinant human follicle stimulating hormone (r-hFSH; Gonal-F) versus highly purified urinary FSH (u-hFSH HP; Metrodin HP), both administered s.c. in women undergoing ovarian stimulation for in-vitro fertilization including intracytoplasmic sperm injection (ICSI). A total of 235 patients started a long gonadotrophin-releasing hormone agonist protocol: 119 received r-hFSH and 114 received u-hFSH HP (150 IU/day) for the first 6 days. Two patients were excluded from the study because they mistakenly received the incorrect treatment combination. Human chorionic gonadotrophin (HCG; 10000 IU, s.c.) was administered once there was at least one follicle 18 mm in diameter and two others > or = 16 mm. In all, 119 (100%) and 102 (89%) of the patients respectively in the r-hFSH and u-hFSH HP groups achieved the criteria for HCG. The mean numbers (+/- SD) of oocytes recovered (the primary endpoint) were 12.2 +/- 5.5 and 7.6 +/- 4.4 in the r-hFSH and u-hFSH HP groups respectively (P < 0.0001). However, the number of FSH treatment days (11.0 +/- 1.6 versus 13.5 +/- 3.7) and the number of 75 IU ampoules (21.9 +/- 5.1 versus 31.9 +/- 13.4) used were significantly less (P < 0.0001) in the r-hFSH group than in the u-hFSH HP group. In patients treated using ICSI (63 patients in each group), no difference in oocyte maturation was observed. The mean numbers of embryos obtained were 8.1 +/- 4.2 and 4.7 +/- 3.5 (P < 0.0001), in favour of the r-hFSH group. In the majority of patients (96 and 99% respectively) only one or two embryos were replaced (mean 2.0 +/- 0.2 and 1.9 +/- 0.1 respectively) in the r-hFSH and u-hFSH HP groups. The clinical pregnancy rates per started cycle and per embryo transfer were 45 and 36%, and 48 and 47%, respectively in the r-hFSH and u-hFSH HP groups (not significant). There were six (5.1%) and two (1.7%) cases of ovarian hyperstimulation syndrome respectively. In conclusion, it was found that r-hFSH was more effective than u-hFSH at inducing multiple follicular development. However, the high rate of low ovarian response in the u-hFSH group compared with our general experience was unexpected. The availability of a gonadotrophin with less inter-batch variation would be beneficial for clinicians. r-hFSH seems to fulfil such a requirement.

Adolescent↗
PubMed1996

Ultrasound studies of vascular and morphological changes in the human uterus after a positive self-test for the urinary luteinizing hormone surge.

The aim of the study reported here was to establish complementary data for changes in uterine size, echogenicity and vascularity during the menstrual cycle relative to a positive self-test for urinary luteinizing hormone (LH) and day 1 of next menses. Thirteen volunteers (aged 23-32 years) with apparently regular menstrual cycles were recruited from the nursing staff. The plan was to examine all women by transvaginal ultrasonography with colour Doppler imaging on day 11 of the menstrual cycle. A urinary LH self-test was to be used daily until a positive result was obtained and the women were to be re-scanned daily until the dominant follicle had ruptured. All women were then to be scanned at least every 48 h (within +/- 2 h of the same time of day) until day 6 of the next menstrual cycle. Matched samples of peripheral blood were taken at the time of each scan for hormone analysis. The main outcome measures were the times of follicular rupture, a positive test result for urinary LH and the start of menses, uterine volume, cavity length, endometrial thickness and grade, pulsatility index (PI), and time-averaged and peak systolic maximum velocities in uterine and radial arteries and in subendometrial vessels. Nine women fulfilled the criteria for an ovulatory cycle, and seven provided data over the complete study. The principal changes relative to a positive urinary LH test were (i) a continued rise in endometrial thickness to days 3 and 4 (this index then remained relatively constant, but the layered appearance was lost) and (ii) a gradual decrease in the uterine arterial PI. There was a significant rise in uterine volume, cavity length and uterine arterial PI around the time of the next menses, and a fall in endometrial thickness and blood velocity in the uterine and radial arteries and subendometrial vessels. The data may have implications for the assessment of reproductive status and the design of future studies on disorders of implantation or menstruation.

Adult↗
PubMed1996

Ultrasound studies of vascular and morphological changes in the human corpus luteum during the menstrual cycle.

OBJECTIVE: To determine changes in corpus luteum (CL) volume, echogenicity, vascularity, and P production relative to a positive test result for urinary LH and day 1 of next menses. SUBJECTS: Thirteen healthy volunteers (age 23 to 32 years). INTERVENTIONS: All women underwent transvaginal ultrasonography on cycle day 11 and a urinary LH self-test was used daily. The plan was to rescan all women immediately after a positive test result and then at least every 48 hours (until day 6 of the next cycle); samples of peripheral blood were taken for analysis. MAIN OUTCOME MEASURES: The times of follicular rupture, a positive urinary LH test, and the start of menses; CL volume and echogenicity, maximum peak systolic velocity and minimum impedance, the circulating levels of serum P, E2, LH, and FSH. RESULTS: Nine women fulfilled criteria for an ovulatory cycle. There was a good correlation between peak systolic velocity, CL volume, and the concentration of serum P from day 4 to 10 after a positive LH test. Peak systolic velocity reached a maximum value between days 7 and 9 relative to a positive urinary LH test and started to decline from day 1 of menses minus 3, 4 days. CONCLUSION: Changes in peak systolic velocity from the time of a positive urinary LH self-test might be a useful adjunct for monitoring CL function.

Adult↗
PubMed1995

Determination of 2-(9-anthryl)ethyl chloroformate-labeled amino acids by capillary electrophoresis and liquid chromatography with absorbance or fluorescence detection.

A new precolumn reagent for amino acid determination, 2-(9-anthryl)ethyl chloroformate (AEOC), was introduced to obtain higher sensitivity in two capillary separation techniques, liquid chromatography (LC) and electrophoresis (CE). The chromophore in the (9-fluorenyl)methyl chloroformate (FMOC) reagent was replaced by anthracene, which resulted in a reagent with very high molar absorptivity (epsilon 256 = 180,000 L mol-1 cm-1). This permits AEOC-tagged species to be detected at nanomolar levels with UV absorbance detection in standard 50-microns-i.d. fused silica capillaries. Weaker absorption bands match the UV argon laser lines of 351 and 368 nm, which allows for convenient laser-induced fluorescence (LIF) detection. In this mode, picomolar limits of detection are obtained. In addition to measuring the limits of detection, we examined micellar electrokinetic chromatography, free solution capillary electrophoresis, and packed capillary LC and compared these methods regarding the separation of amino acids.

Amino Acids↗
PubMed1995

The success rate in a Swedish in-vitro fertilization unit: a cohort study.

OBJECTIVE: To evaluate the cumulative childbirth rate after completion of in vitro fertilization (IVF) treatment including three or, in a few cases, four stimulated cycles. DESIGN: A cohort of 398 couples starting their first IVF treatment between January 1990 and December 1992 were followed until completion of their treatment. RESULTS: Of 826 started cycles, embryo transfer was performed in 793 cycles, giving a mean of 2.0 completed cycles per couple. In addition, cryopreserved embryos were transferred in 228 cycles (0.57 cycles per couple). 204 couples completed their treatment with delivery or with an ongoing pregnancy, 95 couples underwent three stimulated cycles without achieving an ongoing pregnancy and 66 couples cancelled their treatment after one or two cycles because of varying reasons. In seven women no transfer took place. Twenty-six women have not yet completed their planned cycles. Of 398 couples, where the vast majority had completed their IVF treatment, 51% (204) delivered as a result of the treatment. CONCLUSION: IVF treatment combined with freezing of surplus embryos, is a highly effective procedure giving a 'take home baby rate' on a cumulative basis of more than 50% within 1 to 3 cycles.

Adult↗
PubMed1983

Possibilities and limitations of tracing industrial effluents in the sea by means of capillary chromatography.

Certain organic constituents of waste water, such as halocarbons and chlorophenols, can be used to establish the distribution pattern of effluents discharged into the sea. The approach requires simple sampling techniques and highly sensitive and rapid analytical methods. The combination of glass capillary column gas chromatography and electron-capture-detection meets the analytical requirements. The selectivity of the detector, together with the high resolving power of the column, makes it possible to handle the complex sea-water matrix. Selective derivatization directly in the water sample is combined with simultaneous extraction to increase the number of suitable tracers. Halocarbons can be measured at pg/l levels. Chlorophenols are determined at ng/l concentration levels.

Chromatography, Gas↗
PubMed1975

The sum of chlorinated and of brominated non-polar hydrocarbons in water.

It is proposed to use chlorine as a common parameter in the study of the non-polar chlorinated hydrocarbons in the aquatic environment. Also the ratio of the sum of chlorine to bromine may be useful indicator of pollution by such compounds. Detector of chlorine and of bromine in this form is based on neutron activation analysis. Further information on the nature of organochlorine material is obtained by studying variations in the chlorine content with chemical and physical manipulations. Simultaneous determination of known organochlorine micropollutants allows the level of unidentified chlorinated hydrocarbons to be assessed. In samples of fresh- and sea-water so far analyzed, the total content of non-polar organic bound chlorine exceeds that which can be accounted for as polychlorinated biphenyls (PCB) by a factor of 10 to 100.

Bromine↗