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Biomedical subjects

K Sundberg

Publications and source records attributed to K Sundberg.

36 records · Page 2Linked to original sources

Experience with early amniocentesis.

Literature concerning early genetic amniocentesis, obtained before 14-15 weeks of gestation, has been examined and compared. Key figures of post-procedural spontaneous fetal losses have been compared as well as cytogenetic data from the published series. Cytogenetically more samples fail to grow in the early weeks, but the diagnostic accuracy seems to be comparable with that of amniocentesis obtained in the later weeks. A sampling method, improving the cell yield by means of filtration, has been developed in order to lower the risk of culture failure and reduce the reporting time in the gestational weeks 11 to 13. The filter technique is under evaluation in a randomized trial. Detection of neural tube defects with early amniotic fluid sampling is possible, but whether the detection rate is comparable to that of standard amniocentesis remains to be seen. Although the safety of early amniocentesis has not yet been evaluated in a randomised study, data from almost 5,000 cases suggest that the procedure related loss rate is approximately 1%, and thus the same as for standard amniocentesis and chorionic villus sampling.

Amniocentesis↗

Early sonographically guided amniocenteses with filtration technique: follow-up on 249 procedures.

Fetal and neonatal outcome is reported for 249 consecutive low-risk pregnancies in which early amniocentesis was carried out with filter technique, at a mean gestational age of 12.5 weeks, to improve the yield in cell cultures. Three pregnancies (1.2%) were terminated because of abnormal test results, four stillbirths (1.6%) occurred between weeks 33 and 38, and five pregnancies were lost spontaneously after sampling, corresponding to 2% of unintended fetal losses before 28 weeks of gestation. Of the live-born infants, 2.9% were delivered prematurely, all between weeks 32 and 37. Malformations and orthopedic postural deformities were not associated with leakage after amniocentesis and were found at expected rates. None of the cases was lost to follow-up. The increase in abortion rate caused by early amniocentesis with filter technique is likely to be within the same range as that seen after routine amniocentesis and transabdominal chorionic villus sampling, although the sample is too small for a proper risk evaluation.

Abortion, Induced↗

Mosaicism confined to placenta in pregnancies with adverse outcome.

Chorionic villi and fetal tissues from 50 pathological human conceptions at gestational weeks 9-40 were cultured and cytogenetically analyzed to explore the existence of chromosomal mosaicism confined to the extraembryonic tissues and to clarify the relationship between confined placental mosaicism and adverse outcome of pregnancy. Chorionic villi and fetal tissues from 12 second trimester gestations terminated for social reasons served as a control group. In two pathological gestations, true mosaicism was found exclusively in chorionic cells and could not be confirmed in cells derived from the fetal tissues. One of these was severely growth retarded. Concordant results were obtained in all other cases.

Abortion, Induced↗

[Mosaicism confined to placenta in pregnancies with adverse outcome].

Chorionic villi and fetal tissues from 50 pathological human conceptions at gestational weeks 9-40 were cultured and cytogenetically analyzed to explore the existence of chromosomal mosaicism confined to the extraembryonic tissues and to clarify the relationship between confined placental mosaicism and adverse outcome of pregnancy. Chorionic villi and fetal tissues from 12 second trimester gestations terminated served as a control group. In two pathological gestations true mosaicism was found exclusively in chorionic cells and could not be confirmed in cells derived from the fetal tissues. One of these was severely growth retarded. Concordant results were obtained in all other cases.

Adult↗

True trisomy 15 mosaicism, detected by amniocentesis at 12 weeks of gestation and fetal echocardiography.

A case of mosaicism of trisomy 15, with two-thirds of the cells trisomic, was detected at 12 weeks of gestation in amniotic fluid cell cultures obtained with the filtration technique. Ultrasound examination at 13 weeks showed a nodule protruding into the amniotic cavity which was speculated to be remnants of a co-twin, causing the trisomic cell line. At 20 weeks of gestation, a malformation scan (level III) was normal, but supplementary fetal echocardiography revealed a severe cardiac defect (mitral atresia and a ventricular septal defect). Fetal lymphocytes obtained by cordocentesis showed trisomy 15 mosaicism, but only in 5 per cent of the mitoses. After termination, the same percentage of trisomy 15 mosaicism was found in cells from skin and tendon as in the original early amniocentesis. No sign of earlier twinning was found in the placenta or membranes. We conclude that mosaicism in early amniotic fluid obtained by the filter technique in this case reflected the true karyotype accurately and that supplementary echocardiography added significantly to the interpretation of the clinical implications.

Adult↗

Filtration and recirculation of early amniotic fluid. Evaluation of cell cultures from 100 diagnostic cases.

Due to the low cell concentration, cultures from early amniotic fluid specimens usually require 2-3 weeks in culture prior to karyotyping. The purpose of this study was to evaluate the culture quality of amniotic fluid cells from early pregnancy, obtained by a new filter technique. The hypothetical advantage of the technique was that the increased cell yield might reduce the culture time before karyotyping. Culture quality was assessed by the number of colonies, the percentage of colonies containing mitoses in filter and control cultures, and the culture time. The setting was a consecutive clinical trial. One hundred samples were obtained from ongoing pregnancies at 11-14 weeks of gestation (mean 12.8 weeks). By circulating a mean of 26 ml of amniotic fluid through a cell filter system leading the cell-free fluid back to the amniotic cavity, the cell yield was increased in the sample of 7 ml corresponding to the dead space of the filter system. The culture results were compared with control cultures from 5 ml samples drawn from the same pregnancies prior to recirculation. The cultures from the first flushing of the filter system yielded 2.6 times more colonies and in total 4.2 times more colonies were found in the three cultures grown from each filter sample when compared with the control cultures. Moreover, the filter cultures showed significantly more colonies with mitoses. The mean culture time was 8.0 days for the filter cultures, from which the karyotypes were analysed. The controls would have needed more time in culture to fulfil the diagnostic criteria for karyotyping. One case of 47,XY,+21 was found; the rest had normal karyotypes. We conclude that the filter technique improves the culture quality of early amniotic fluid samples and allows early arrest of the cultures.

Amniocentesis↗

Contact allergy to a fatty acid ester component of cutting fluids.

6 patients employed in the metalworking industry developed a hand dermatitis after exposure to a vegetable-oil-based cutting fluid. After thorough investigation, including patch testing with components in the cutting fluid as well as an oil and cutting fluid series, contact allergy was demonstrated to a fatty acid ester EM-550 in the cutting fluid.

Adult↗

Gamete intrauterine transfer.

Gamete intrauterine transfer has been performed at a very limited scale until now. The main target group of patients for such a treatment would be women with infertility due to the tubal factor, but other infertile patients could benefit also, as the procedures reduce incubation time in the laboratory and implies fertilization in vivo. Few studies have been reported from 1982 to 1990 on the transfer of oocytes and spermatozoa directly to the uterus, and only five clinical pregnancies have been achieved. Transfer of oocytes and spermatozoa inside a biodegradable capsule has only been performed in one study comprising 26 cycles with no ensuing pregnancies. A critical evaluation and a status is carried out.

Embryo Transfer↗

Synthesis, NMR spectra and function of peptides with alpha-methylserine attached to the RGD sequence of osteopontin.

The three-dimensional structure of the RGD-adhesion sequence has been studied previously by means of linear and cyclic peptides. These peptides show widely differing affinities to integrins, ascribed to a strong dependence on steric factors in the receptor recognition. Insertion of alpha-methylserine next to the RGD sequence in this investigation resulted in lower affinity for both stereoisomers, and several small changes in chemical shifts and coupling constants relative to the parent serine peptide GRGDSL.

Magnetic Resonance Spectroscopy↗

Amniocentesis with increased cell yield, obtained by filtration and reinjection of the amniotic fluid.

In order to increase the cell numbers obtained by amniocentesis, a new amniocentesis technique has been developed and we report preliminary results. The amniotic fluid is aspirated in the usual manner and reinjected immediately into the amniotic cavity after passage through a filter which retains the cells from the fluid. By this procedure, the cells from a relatively large volume of amniotic fluid are concentrated on the filter while only a small volume of amniotic fluid is finally removed. The method has been tested on 30 pregnant women referred for prenatal diagnosis. The mean culture time was 8.3 days and no immediate side-effects were observed.

Journal Article↗

Intrauterine capsules for incubation of gametes and subsequent release of embryos.

In order to obtain incubation in uteri of spermatozoa, oocytes, and embryos, for treatment of patients referred for in vitro fertilization, a capsule was produced which could contain the human gametes and allow human fertilization and embryo growth after intrauterine introduction. Agar was chosen for capsule material and a mold was constructed for the production of capsules. The material was tested in vitro using mouse embryos and human oocytes and sperm. Intrauterine resolution was tested on mice and by insertion on 11 women. Empty capsules were inserted into the uterine cavity in 15 cycles the day after the luteinizing hormone peak and followed by daily ultrasound examinations. The resolution time was adjusted by changing the wall thickness of the capsules. The final type was dissolved after 3 to 4 days. No complications were observed and capsules could be inserted on all occasions. The major problem was expelling of capsules, which occurred in seven cycles. The problem seemed to be solved by the administration of indomethacin at the day of insertion.

Adult↗

Intrauterine fertilization capsules--a clinical trial.

Treatment of 26 women with tubal infertility was attempted using intrauterine capsules loaded with oocytes and spermatozoa. The stimulation protocol was as used for in vitro fertilization and embryo transfer and consisted of short-term use of Buserelin, human menopausal gonadotropin, and human chorionic gonadotropin. Oocytes were collected by ultrasonically guided transvaginal aspiration, and spermatozoa were prepared by swim-up technique. The gametes were placed in agar capsules 4 hr after oocyte collection, and the capsules were introduced to the uterine fundus using an insertion tube and piston from an intrauterine device. Six complete capsules and parts of two other capsules were expelled. None of the women became pregnant, compared with a pregnancy rate of 21% per aspiration following in vitro fertilization and embryo transfer during the same period.

Buserelin↗

The milk oligosaccharide, lacto-N-fucopentaose I, inhibits attachment of mouse blastocysts on endometrial monolayers.

Seven oligosaccharides isolated from human milk were tested for their effect in an in-vitro model of mouse blastocyst adhesion and trophoblast outgrowth on endometrial epithelial monolayers. One compound, lacto-N-fucopentaose I (LNF I), produced a significant reduction in the percentage of attached and outgrown blastocysts after co-culture for 72 h (P less than 0.001). No significant effect of any other tested oligosaccharide was obtained.

Animals↗

Comparative multi-center study with TRUE Test and Finn Chamber Patch Test methods in eight Swedish hospitals.

292 individuals were patch tested with twelve allergens, using a new patch test technique, TRUE Test (TT). As controls, the same allergens in standard concentrations in petrolatum were applied using the Finn Chamber technique (FC). The allergen doses used in TT were chosen according to results from a previous serial dilution patch test study. There were reactors to all twelve allergens. The concordance of positive reactions between TT and FC was 78%. 10% were indicated only with TT and 12% FC only. Irritant reactions occurred in the same order of magnitude for the two tests. Weak positive, uncertain, and irritant reactions observed with the different test methods used, indicate minor errors of allergen dosage in both. The investigation indicates that the TRUE Test method is simple to handle, is well standardized and gives good accuracy with the 12 allergens investigated.

Allergens↗

Animal model for assessment of skin irritancy.

Irritant skin reactions from repeated open applications of low concentrations of sodium lauryl sulphate (SLS) have been studied macroscopically and microscopically in guinea pigs. After 3 applications daily for 3 days, 2% SLS aqueous solutions gave a naked eye assessment, increase in epidermal thickness and total dermal inflammatory cell response, which was greater than for a 1% SLS solution. The dermal inflammatory cell response was mainly mononuclear (lymphocytic) in nature. With the SLS reactions as control, various organic solvents were studied and ranked against the SLS reactions and internally. Trichlorethylene was the most irritant solvent, ranking as high as 2% SLS. Other chlorinated hydrocarbons and aromatic hydrocarbons tested caused irritant reactions. The alcohols and acetone gave no reaction. White spirit was as irritant as trichlorethylene. Thinners were less irritant, around the level of the 1% SLS control reaction. The 4-day experimental design is a convenient and suitable animal model for screening irritant potential, and provides information relevant to the pathogenesis of irritant contact reactions.

Animals↗