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Biomedical subjects

P A Riss

Publications and source records attributed to P A Riss.

9 recordsLinked to original sources
PubMed1989

[Simple and clinically useful documentation on the vulva using a personal computer].

We developed a simple menu driven database on personal computer for classification and documentation of vulvar lesions (IBM-PC, dBaseII). Vulvar lesions were classified according to morphologic appearance: red, white, dark, ulcer, small tumor (less than 1 cm), large tumor. The data for each category are entered in multiple choice form and stored in a separate database file. For each category an automated table of the frequencies of the different diagnoses is provided, individual patients and variables can easily be accessed through the database query language.

Documentation↗
PubMed1989

Serum progesterone and human chorionic gonadotropin in very early pregnancy: implications for clinical management.

We studied beta-human chorionic gonadotropin (beta-HCG) and progesterone (P) in maternal serum in 71 patients with a positive urine pregnancy test with a threshold of 50 U HCG/liter urine and an ultrasound examination without demonstrable fetal heart beat. Patients were divided into three groups: ongoing intra-uterine pregnancy of more than 12 weeks duration (n = 23), ectopic pregnancy (n = 14), and abnormal intra-uterine pregnancy (blighted ovum, early spontaneous abortion) resulting in dilatation and curettage (n = 34). We found that both beta-HCG and progesterone levels were significantly lower in abnormal pregnancies but that there was less overlap between the progesterone values in normal, ectopic and abnormal pregnancy as compared to beta-HCG levels. There was a positive correlation between beta-HCG levels less than 5000 mU/ml and serum progesterone in ectopic pregnancies but not in normal or abnormal intra-uterine pregnancies. The size of the gestational sac correlated with serum beta-HCG levels but not with serum progesterone levels in normal intra-uterine pregnancies. We conclude that serum progesterone levels (cut-off point 15 ng/ml) in very early pregnancy can be helpful to differentiate between normal intra-uterine pregnancy and abnormal intra-uterine or ectopic pregnancy.

Chorionic Gonadotropin↗
PubMed1989

Morphologic and functional aspects of pelvic floor muscles in patients with pelvic relaxation and genuine stress incontinence.

Thirty women (mean age 49 years; range 33-74) with mild to moderate pelvic relaxation and genuine stress incontinence underwent preoperative urodynamic studies. Biopsy specimens from the levator ani muscles during vaginal hysterectomy and repair were evaluated for the number and the individual diameters of type I (slow-twitch) and type II (fast twitch) fibers. Biopsies from 11 women revealed striated muscle tissue, whereas no muscle tissue was observed in the other 19. Compared with patients without muscle tissue, subjects with positive muscle findings showed significantly higher transmission ratios (55.0 +/- 23.4 versus 32.9 +/- 22.1%; P less than .05). Mean diameter and counts of types I and II muscle fibers decreased significantly with age (P less than .05). Urethral closure pressure during stress significantly increased with mean diameter of type II muscle fibers (P less than .05). In contrast to patients with severely damaged pelvic floor muscles, the presence of slow-twitch fibers is associated with improved support of the pelvic viscera, especially under conditions leading to intra-abdominal pressure rise. The presence of fast-twitch fibers improves the periurethral continence mechanism, resulting in an increase of urethral closure pressure during stress.

Biopsy↗
PubMed1988

Development and application of simple expert systems in obstetrics and gynecology.

Expert systems have become increasingly popular in medicine for the support of medical decisions, e.g. diagnosis or treatment. We describe the development and application of 2 simple rule-based expert systems, one used for cycle stimulation in our in vitro fertilization program and the other for preoperative assessment of urinary incontinence. The programs were written using a commercially available expert system shell, are run on a standard personal computer, and are in actual use in our department. Though it is doubtful that simple expert systems can be superior to a human expert we feel that expert systems are very useful in the standardization of protocols and are a valuable teaching instrument.

Decision Making, Computer-Assisted↗
PubMed1988

The predictive values of single and combined urodynamic parameters.

We calculated the predictive values of single urodynamic parameters with regard to five urodynamic diagnoses: genuine stress incontinence, mixed incontinence, motor urge incontinence, sensory urge, and no incontinence demonstrable. We now constructed tree diagrams by using the parameters with the highest predictive values (recursive partitioning analysis) and calculated the predictive values of the combinations of parameters in each subset. The tree diagrams and the predictive values of the combined urodynamic parameters offer insights into the relevance of different urodynamic parameters and can be used in developing programs for computer-assisted medical decision making in urodynamics.

Female↗
PubMed1984

Obstetric analgesia and immunoreactive endorphin peptides in maternal plasma during labor.

We studied the effect of obstetric analgesia on maternal plasma levels of immunoreactive endorphin peptides (ir-EP) during labor and the postpartum period in three groups of parturients: group I (n = 22) had no analgesia, group II (n = 20) received pethidine intramuscularly, and group III (n = 10) had continuous epidural analgesia. Initial levels of ir-EP were similar in all three groups. Patients without any medication and patients on pethidine showed a significant rise in ir-EP in late labor and at delivery. Epidural analgesia was characterized by constant levels of ir-EP during labor and an insignificant rise at delivery.

Adult↗
PubMed1983

Immunoreactive endorphin peptides in amniotic fluid during labour.

Immunoreactive endorphin peptides (irEP) were measured in term amniotic fluids at induction by amniotomy (n = 8), during early and late first stage of labour (n = 52), at vaginal delivery (n = 30) and at caesarean section (n = 10). Individual values ranged from 50 to 222 pg/ml, but mean values did not differ significantly, and serial determinations revealed that irEP in the amniotic fluid remained almost constant in each woman from the first stage of labour through to delivery. There was no correlation between pathological changes in the cardiotocogram or low umbilical artery pH and irEP levels in the amniotic fluid at vaginal delivery. We conclude that immunoreactive endorphin peptides in the amniotic fluid probably are of fetal or placental origin and do not reflect fetal wellbeing or distress.

Amniotic Fluid↗
PubMedDate not supplied

Development of an expert system for preoperative assessment of female urinary incontinence.

We developed a simple expert system for preoperative assessment of women complaining of involuntary loss of urine and scheduled to undergo surgery for incontinence. The aim of the system was to use the parameters obtained at urodynamic investigation to arrive at the correct diagnosis. We used an IBM-PC with two disk drives and 256k RAM, and the expert system shell EXSYS, a rule based system with the possibility of assigning probabilities to the different solutions. To write the rules forming the knowledge base we used a two-fold approach: we constructed tree diagrams for each diagnosis and calculated the corresponding predictive values (statistical approach), and we added rules based on our experience (heuristic approach). The expert system has been found reliable in a clinical setting and is useful for teaching purposes.

Diagnosis, Computer-Assisted↗