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Biomedical subjects

N Lang

Publications and source records attributed to N Lang.

At least 91 records · Page 5Linked to original sources
PubMed1990

Resection guided by antibodies (REGAJ): a diagnostic procedure during second-look operation in ovarian cancer patients.

A hand-held probe has been used to localise the 131I-labelled antibody OC125 during second-look operation (SLO) in 22 ovarian cancer patients. In six patients microscopic cancer was detected with the procedure and a further six patients with areas of increased radioactivity during SLO developed recurrent disease within 1-4 months. We suggest examining resection guided by antibodies as a possible means of removing antigen-producing cancerous tissues during surgery.

Antibodies, Monoclonal↗
PubMed1989

Malignant and normally developing trophoblastic cells of human placenta display different characteristics defined by histochemical and biochemical mapping of endogenous lectins.

Trophoblastic cells with their strictly controlled propensity for invasive growth hereby bear limited resemblance to malignant cells. Therefore, detailed description of molecular characteristics of this cell type in comparison to histologically related tumor cells may aid in defining physiologically relevant differences. In view of the potential importance of selective protein-carbohydrate interactions in recognitive processes, labelled neoglycoproteins were employed to evaluate systematically the presence and distribution of sugar receptors in tumor cells of chorionepithelioma and in trophoblastic cells of an early stage of gestation. Control reactions in glycohistochemistry, involving prolonged incubation, pH variation and use of nucleotides excluded the possibility that glycosidases or glycosyltransferases govern the sugar-specific binding to the tissue sections. Pronounced differences were detected in the expression of receptors (lectins) for alpha- and beta-glucosides as well as for N-acetylgalactosamine and N-acetylglucosamine. Further differences were revealed by probing both types of tissue with lactosylated, fucosylated, xylosylated and sialylated carrier protein. Upon developmental maturation of the normal cells in placenta the extent of binding of the neoglycoproteins decreased. The glycohistochemical differences between malignant and normally developing trophoblastic cells were found to be reflected in the alteration of expression of certain endogenous lectins, as ascertained by affinity chromatography and gel electrophoretic analysis. Consequently, we assume that the transient presence of certain endogenous lectins during early stages of gestation and their differential expression in relation to tumor cells of chorionepithelioma may be relevant for the special invasive and adhesive behavior of human trophoblastic cells.

Choriocarcinoma↗
PubMed1989

Some observations on the effect of a GnRH analog in ovarian cancer.

Observations in healthy women led us to suppose that the increase of the tumor marker CA 125 observed during progression of ovarian cancer could be dependent on pituitary gonadotropins. Therefore we administered the GnRH-analog, DTrp 6-LH-RH, to 19 patients with progressive ovarian cancer and increasing CA 125 serum levels. When compared to 11 untreated patients, CA 125 levels increased at a considerably slower rate in 9 of 11 patients who were treated with the substance for more than 3 months. This was associated with stable disease, ranging from 4 to 20 months so far. The further analysis of 2 patients who developed an increase in CA 125 serum levels and a progression of disease during treatment demonstrated that FSH and LH levels had escaped suppression. The results support our assumption, that gonadotropins may be involved in the mechanisms leading to increasing CA 125 concentrations in ovarian cancer. The reduced increase of CA 125 and the observed stabilisation of disease during pituitary blockade offers a rationale for GnRH analogues in the therapeutic approach to this disease.

Adult↗
PubMed1989

[Observations on the course of advanced ovarian cancers following medicamentous reduction of hypophyseal gonadotropins].

Previous observations in healthy women showed, that the increase of CA-125 observed during progression of ovarian cancer could be dependent on pituitary gonadotropins. Therefore, the GnRH-analog D-Trp 6-LH-RH was administered to 17 patients with progressive ovarian cancer and increasing CA-125 serum levels. 12 of 17 patients who had been treated for more than three months exhibited a considerably slower increase of CA-125 which was associated with a remarkable stabilisation of disease. The other patients, who suffered from progressive disease, an increase of the gonadotropins could be detected during the analog treatment. These observations strengthen the suspicion of the critical role of gonadotropins in the production of CA-125 and the progression of ovarian cancer.

Adult↗
PubMed1989

[Effect of obstetric-perinatal measures on mortality and early morbidity of premature infants weighing 500 to 1,500 grams].

In a retrospective analysis of perinatal influencing factors in 186 premature newborns of the Department of Gynaecology of the University of Erlangen covering the period from 1982-1987 with birth weights between 500 and 1500 grams, the mortality and early morbidity were analysed, as characterised by cerebral haemorrhages, respiratory distress syndrome and infections insofar, as they had been connected with the obstetrical approach and paediatric intensive-care treatment, 45 infants born in 1982/83 were compared with 141 infants, who had been subjected to a different treatment approach during 1984 to 1987. During the second period, there was a marked drop both in mortality and in the incidence of asphyxia-induced severe cerebral haemorrhage and of the respiratory distress syndrome. A shortened latency period after premature rupture of the amnion, and a more pronounced presence of a neonatologically experienced team of paediatricians were found to be significant obstetric liberal influencing factors in determining the need to perform Caesarean section. The triplication of the frequency of Caesarean section observed resulted in a 50% reduction in perinatal mortality and morbidity. Infants with pelvic presentation benefited most from the more liberal performance of Caesarean section, as did infants with vertex presentation. Shortening of the latency phase in premature rupture resulted in a marked reduction in infection morbidity and mortality. Therefore we conclude, that the frequently practised procrastination with the aim to await an improvement in lung maturity should be replaced by a more active obstetric management, avoiding both infection and birth trauma. Obstetric decisions should be based rather on prenatal estimation of weight than on the calculated gestational age. At present, the lowest birth weight associated with the expectation of a healthy life is considered to be 750 grams.

Asphyxia Neonatorum↗
PubMed1989

[Functional forms of prolapse].

234 women were examined via microtransducers both with 100 ml bladder contents in recumbent position and with 300 ml bladder contents in seated position. The types of prolapse or descensus were categorised after modification according to Green. The quotient from the maximal urethral occlusion pressure at rest recorded with 300 ml bladder filling in seated position and 100 ml bladder filling in recumbent position (known as pressure quotient at rest) showed changes dependent on the type of prolapse (Type I: less than or equal to 1, Type II: less than 1, Type III: greater than 1 (n.s.), Type IV: greater than 1). These functional changes can be explained by the stress-dependent dynamics of each individual form of prolapse. An additional combined form was described (Type III) which was found to be a special form both anatomically and functionally.

Female↗
PubMed1989

Cryopreservation of human and rabbit oocytes and one-cell embryos: a comparison of DMSO and propanediol.

The aim of this study was to improve the cryopreservation of human oocytes and pronuclear embryos. One-step and multiple-step addition of dimethyl sulphoxide (DMSO) and 1,2-propanediol (PROH) and three different freezing protocols with intermediate temperatures of -35, -70 and -110 degrees C were investigated. This work was performed using rabbit oocytes as well as human oocytes and one-cell embryos from the routine IVF programme. Also, human polyploid pronucleate oocytes were used in controlled prospective studies of morphological intactness and development in vitro. Rabbit oocytes survived best (113/126) when PROH was added in one step and controlled freezing stopped at -110 degrees C. But the development was better (141/187) if DMSO was added in multiple steps and the oocytes were cooled to -70 degrees C before being plunged into liquid nitrogen. The mode of addition of the cryoprotectant influenced development only if slow freezing was stopped at -35 degrees C (51 versus 34%). Using PROH, the development after thawing was also better if cooling was stopped at -35 degrees C (51 versus 37%) and DMSO was superior to PROH when the oocytes were cooled slowly to -110 degrees C (66 versus 37%). In the human, significantly more pronucleated than unfertilized oocytes developed after freezing (92 versus 50%). The best results were achieved with pronuclear embryos using 1.5 M PROH and cooling to -110 degrees C, when 91.7% of the surviving oocytes developed further. This is a marked improvement of the development rate and comparable to embryo freezing.

Animals↗
PubMed1989

Comparative results on survival of human and animal eggs using different cryoprotectants and freeze-thawing regimens. I. Mouse and hamster.

The achievement of successful pregnancies and births after in-vitro fertilization and embryo transfer of frozen-thawed human oocytes has stimulated further work on improving the established methodology. The present investigation was conducted on 1837 mouse oocytes, 1785 mouse pronuclear stage embryos, 1400 hamster oocytes and 1024 hamster pronuclear-stage embryos. In an effort to study the advantages and disadvantages of a newly introduced, 1,2-propanediol (1,2-PROH)-based system over the conventionally used dimethylsulphoxide (DMSO)-based methodology, a direct, prospective comparison between the two cryoprotectants was undertaken in a randomized trial. The combination of 1,2-PROH and DMSO potentiates their cryoprotective effect on mouse and hamster eggs. 1,2-PROH seems to improve cryopreservation in the animal system, though not significantly. Four different protocols were used to evaluate the effects of two changing experimental parameters. These were, firstly, the intermediary temperature attained before placing the cells into liquid nitrogen and, secondly, the modification of the method of adding and removing the cryoprotectant. The morphological survival rate, fertilization rate and developmental rate were significantly better in the low intermediary temperature compared with the high intermediary temperature system of cryopreservation. In addition, the rate of zona pellucida breakdown diminishes considerably in the former compared with the latter system. The 'rapid' sucrose method of cryoprotectant equilibrium and removal showed, in most groups, results which were lower than, or equal to, the traditionally used 'multiple-step', 'slow' method.

Animals↗
PubMed1989

Comparative results on survival of human and animal eggs using different cryoprotectants and freeze-thawing regimens. II. Human.

A total of 269 human pronuclear embryos and 84 oocytes were subjected to four different protocols of cryoprotectant equilibration, washing out and freeze-thawing. The morphological survival, rate of development, fertilization in vitro and overall survival rate were estimated in the groups of fresh, aged oocytes, diploid and multipronuclear embryos used. With some restrictions, the conclusion can be drawn that slow, low intermediary temperature 1,2-propanediol (1,2-PROH) and 1,2-PROH/dimethyl sulphoxide (DMSO) systems are superior to the rapid, high intermediary temperature 1,2-PROH and the traditionally used DMSO systems. The best success rates were reached with the combination of cryoprotectants in the low intermediary temperature group. Thirty-three patients had 37 transfers of cryopreserved pronuclear embryos (n = 103), resulting in eight pregnancies (24.2% per transfer) thus doubling the pregnancy rate in the stimulation cycles for the same period (21% per transfer). Thawing at a rate of 50 degrees C/min is not incompatible with the survival of slowly frozen human oocytes and pronuclear embryos cooled to an intermediary temperature of -70 degrees C using the DMSO system.

Cell Survival↗
PubMed1989

Resolution of discrepant typings observed in paternity testing.

Discrepant results in phenotyping the red blood cells (RBCs) of a child and his alleged parents were attributable to a contaminating antibody, anti-Bgb (HLA B-17), in typing reagents (anti-C and -Cw). This case demonstrates the necessity for using reagents from at least two sources for paternity testing.

Journal Article↗
PubMed1988

Pregnancy following repair of a congenital atresia of the uterine cervix and upper vagina.

A case of congenital atresia of the uterine cervix combined with atresia of the upper vagina and without any other anomalies is reported. Direct anastomosis of cervix and vagina resulted in a restoration of reproductive function. The patient conceived 6 years afterward and delivered a healthy boy by cesarean section at 31 weeks of gestation. Therapeutic reconstructing options for this kind of genital tract malformation with respect to reproductive function are discussed.

Adolescent↗