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Biomedical subjects

S Potthoff

Publications and source records attributed to S Potthoff.

At least 19 recordsLinked to original sources
PubMed2006

N-cadherin engagement provides a dominant stop signal for the migration of MDA-MB-468 breast carcinoma cells.

The development of a primary tumor as such is not the main cause of death, but is rather the spreading of metastases, which causes over 90% of deaths in cancer patients. This largely depends on the ability of tumor cells to migrate away from the tumor and relocate at other areas of the body. Cell migration is known to be regulated by various extracellular signal substances such as neurotransmitters. However, before single tumor cells can start to invade into distant tissue, they have to dissociate from the primary tumor. This requires the disruption of cell-cell contacts, which are provided by a plethora of adhesion molecules like the family of cadherins. Using our well, established three-dimensional collagen-based cell migration assay, we show that engagement of N-cadherin results in a significant decrease of the spontaneous and the norepinephrine-induced migration of MDA-MB-468 breast carcinoma cells, which was due to an increase in the average break length. Moreover, this N-cadherin driven influence on the migratory activity is intracellularly integrated via multiple signaling pathways. Our results show that the impact of N-cadherin on the locomotion of MDA cells involves the activation of the adenylyl cyclase and the phosphatidylinositol-3-kinase (PI3K), but is independent of the protein kinase C (PKC) alpha. In summary, we provide evidence that the engagement of N-cadherin provides a stop signal for breast carcinoma cell migration, and accordingly the use of anti-N-cadherin antibodies or soluble ligands might be a tool to inhibit metastasis formation in E-cadherin negative but N-cadherin positive tumors.

Breast Neoplasms↗
PubMed2004

[Umbilical cord stromal cells (UCSC). Cells featuring osteogenic differentiation potential].

The identification of appropriate cell types is necessary to establish cell-based therapies in regenerative medicine. These cell types must (1) be available in an appropriate amount, (2) be easy to obtain, (3) be sufficiently expandable in vitro, and (4) fit to or at least be able to differentiate into the required cell type. Since the umbilical cord is available without any intervention and represents a notable amount of tissue, we consider it to be a promising source for isolating cells for cell-based therapies. This study demonstrates that umbilical cord stromal cells (UCSC), the connective tissue cells of the umbilical cord, can be isolated in sufficient quantities and be well expanded. UCSC feature phenotypic plasticity and thus are functionally similar to stem cells. UCSC can be differentiated into cells with osteoblastic properties (expression of alkaline phosphatase, formation of bone nodules). It is concluded that the umbilical cord should no longer be regarded as valueless tissue and be unthinkingly discarded. Instead, it should be considered a valuable resource for the isolation of potent cells for cell-based therapies, especially for treatment of bone defects.

Alkaline Phosphatase↗
PubMed1999

Evaluation of a computerized contraceptive decision aid for adolescent patients.

Recent efforts to involve patients more actively in therapeutic decisions have suggested the relevance of computer-based interventions at clinic visits. This paper presents a longitudinal, experimental study evaluating a computer-based contraceptive decision aid in Chicago and Madison family planning clinic visits. Patient interviews at three time points evaluated patient acceptance by and program impact on 949 young women. Both Chicago and Madison patients reported high acceptance. The program resulted in improved short-term knowledge and confidence in oral contraceptive (OC) efficacy for Chicago and Madison patients. In addition, compared to their control group, Madison experimental group patients had higher OC knowledge 1 year after the initial visit and a trend for fewer pregnancies (P < 0.074). Compared to their control group, a higher percent of the Chicago experimental group patients adopted OC's after stating their intention to do so at the initial visit. Exposure to the computer program had no observable impact on the number of months on the oral contraceptive for Chicago or Madison patients. Overall findings suggest the usefulness of informatics tools as a supplement to patient-provider interactions.

Adolescent↗
PubMed1997

Improving hospital discharge planning for elderly patients.

Hospital discharge planning has become increasingly important in an era of prospective payment and managed care. Given the changes in tasks, decisions, and environments involved, it is important to identify how to move such planning from an art to an empirically based decisionmaking process. The authors use a decision-sciences framework to review the state-of-the-art of hospital discharge planning and to suggest methods for improvement.

Activities of Daily Living↗
PubMed1995

The development of integrated service networks in Minnesota.

The formation of health insurance purchasing alliances in Minnesota has caused a restructuring of the provider system. One of the results has been the formation of competing delivery systems that organize hospitals, physicians, and insurance plans into vertically and horizontally integrated organizations termed integrated service networks (ISNs). This article describes the formation of these ISNs and identifies some of the salient features that distinguish them from other provider systems.

Capitation Fee↗
PubMed1982

Kinetics of the translactal passage of digoxin from breast feeding mothers to their infants.

In order to find out whether digoxin therapy of nursing mothers might produce discomfort in suckling infants we have investigated the kinetics of the transfer of digoxin from plasma to milk in 11 nursing mothers. After intravenous or oral application of a single dose of 0.5 mg or 0.75 mg digoxin simultaneous serum, fore- and hindmilk samples were taken. Obviously, a rapid equilibrium occurred between the serum and the milk compartments and there was no difference between fore- and hindmilk. All three digoxin concentration profiles ran parallel with a milk to serum ratio of 0.6 to 0.7. The curves could best be fitted by the sum of two exponential functions. For predicting the digoxin intake into the suckling infant, simulations were carried out on the basis of two coupled compartment models. When the kinetic milk data as well as the kinetic data obtained in infants were fitted by this model it could be shown that even in the case of long half-lives only about 3% of the therapeutic drug levels were reached in the baby. Thus, one can conclude that digoxin accumulation to toxic concentrations should not occur in infants of women treated with appropriate doses of digoxin.

Adult↗
PubMed1981

Treatment of diabetes mellitus and pregnancy.

The pregnancy of woman with diabetes mellitus poses a high risk. During the pre-insulin era the newborn had a 40% chance of survival and there was high mortality in the mothers. Only in recent years has it been possible to decrease perinatal mortality to 2-4% due to the cooperation of diabetologists, obstetricians, and pediatricians in centers with much experience in supervision of mother and child. In the foreground of treatment are the following prerequisites: (1) close metabolic supervision of the mother allowing blood-glucose values between 60-120 mg/dl and mean blood glucose per day around 85 mg/dl during the course of pregnancy; (2) intensive supervision of the fetus; (3) early recognition and adequate treatment of complications. Close metabolic supervision succeeds only by way of blood-glucose self-control. To decrease the rate of deformities, the close metabolic supervision apparently has to commence before conception. This management no longer requires delivery according to the White scheme.

Congenital Abnormalities↗
PubMed1981

[Hyperglycemia as a risk factor in pregnancy (author's transl)].

Glycosylated hemoglobins were used for the retrospective assessment of glucose metabolism, for therapy control, and as predictor of the weight of the newborn. Glycosylated hemoglobins were determined with the microcolumn method in 50 pregnant diabetics, in 11 overweight pregnant women, in 11 pregnant women under tocolytic treatment, and in 28 metabolically healthy women. Whereas the levels of glycosylated hemoglobins were found to be reduced in metabolically healthy women, the corresponding levels were increased in tocolytically treated, adipose, and diabetic pregnant women. The HbAI values correlated with the mean values of the daily blood glucose profiles (r = 0.79 - 0.94) and decreased during improvement of the metabolic state. A statistic correlation could not be established between the maternal HbAI and the weight of the newborn as the pregnancy period is shortened by dearrangement of the carbohydrate metabolism.

Blood Glucose↗
PubMed1977

[Follow-up of patients who underwent reduction mammoplasty according to Strombeck between 1972 and 1975. Postoperative complications and results. Modification of the technique. Postoperative mammographic results (author's transl)].

Follow-up examinations were carried out in 60 women who underwent a reduction mammoplasty. Their review concentrated on the questions of the frequency of postoperative complications, the possibility to avoid complications by a modification of the technique and the question of mammographic evaluation of the breast in the face of scars from the mammoplasty. There were 12 severe complications. There were 6 necroses of the nipples, there were 3 abscesses, there were 2 suture fistulas and there was one case of massive hematoma. The complications depend on the amount of tissue resected. Especially necroses of the nipples depend upon the amount of tissue resected. With increasing experience of the surgeon, the nipple is moved without tension by lateral division of tissues and omission of resection of tissue above the nipple. This reduces the risk of necrosis of the nipple. Ugly scars are avoided by additional subcutaneous dexon double O sutures and additional subcuticular structures. Prolonged immobilization and later removal of the sutures help to obtain fine scars. A comparison of the preoperative and postoperative mammographies showed that 78% of the X-rays could be evaluated for carcinoma more readily postoperatively than before. For the differential diagnosis to scars from the operative, a preoperative and postoperative mammogram is necessary for comparison.

Adolescent↗