David R. Bolling

The second stage of labor: Factors influencing duration

Prolonged second stage of labor is associated with increased perinatal mortality. Factors influencing second-stage duration are poorly understood. This study was undertaken to characterize those factors. A population of 473 nulliparous women and 491 multiparous women with spontaneous vaginal deliveries were analyzed extensively with history, physical examination (including clinical pelvimetry), labor and delivery data, and neonatal measurements. On the basis of stepwise multiple linear regression, epidural analgesia (p less than 0.0001), active-phase duration (p less than 0.0001), parity (p less than 0.0001), height (p less than 0.0004), birth weight (p less than 0.0003), and station at complete dilatation (p less than 0.027) predicted second-stage duration. The sum of their effect, however, accounted for less than 25% of the variability in second-stage length (total R2 = 0.233), leaving 75% of the variance unexplained.

Break Points in Human Chromosomes

Break points of structural rearrangements of human chromosomes can be identified by banding techniques. The present study attempts to analyze the randomness and the distribution of the reported spontaneous break points in the human genome. Reports of break points in structural rearrangements of human chromosomes from the published sources up to October 1976 were analyzed. Based on the assumption that each unit length of band has an equal chance of being broken, chi2 tests show that positions of breakage are highly non-random; that is, breaks are more frequent in the negative band areas and in the centromeric and terminal regions. In double-break rearrangements the same band types tend to rejoin. The distribution of breaks is not proportional to the chromosome length. The longer chromosomes (i.e., 1--12, X) have a lower number of breaks per unit length, while the shorter chromosomes (i.e., 13--22, Y) have a greater number of breaks per unit length with the exception of chromosomes 4, 9, 10, 16, 17, 19, 20 and X. Out of the whole genome, chromosomes 9, 13, 18, 21, 22 and Y have the most breaks per unit length and chromosomes 16, 6, 2, 3 and 19 have the fewest. 18p11, 21q22 and Yp11 are the three bands with most frequent breaks. There are 53 bands where no breaks have been reported.

Evaluation of dermal patterns in Down's syndrome by predictive discrimination. II. Composite score based on the combination of left and right pattern areas.

Independence of left and right dermal pattern areas were examined in Downs syndrome patients and controls. A composite score was then developed as a laboratory test to confirm the clinical diagnosis of Downs syndrome. The score demonstrates better discrimination by correctly scoring 97.7% of the individuals tested whereas the single pattern scoring method correctly scored 96.6%. An element of simplicity is also gained by using composite scores. It corrects in part the error due to correlation of the occurrence of patterns on the two sides.

The ENCU scoring system: A strategy for solving a class of single-locus genetic counseling problems

A general rule is derived for calculating the conditional probability of a pedigree given that the consultand is a carrier. The method is designated the ENCU system. It is a generalization to accommodate all unilocal systems of inheritance with arbitrary penetrance operating independently in relatives of the ENSU system previously described (Murphy 1970a). The amount of information provided by the normal phenotypes of a person and his descendants is expressed in units of equivalent genotypically normal offspring (ENCUs). The method is applied to a typical genetic counseling problem, and it is shown that a considerable reduction in the quoted risk is obtained because the ENCU system takes into account the normal phenotypes of potential carriers of an incompletely penetrant gene.

A matrix method for calculating recurrence risks of unilocal disorders for genetic counselling.

A matrix method to calculate conditional likelihoods in a pedigree and use them to determine recurrence risks for unilocal disorders in genetic risks is presented in this paper. Different matrices are assigned to individual members of the pedigree and combined into matrix expressions. The method is explained for X-linked recessive conditions and autosomal dominant conditions with incomplete penetrance.

Dermatoglyphic studies of the 47,XYY male.

The dermatoglyphics of 61 47, XYY patients and 166 46, XY controls were compared. The data on 50 47, XYY and 50 46, XY individuals were used to formulate an index score for any unknown having a 47, XYY karyotype. One hundred and sixteen 46, XY individuals were tested on this index and only 65 were correctly diagnosed as 46, XY males. Two 47, XYY individuals were tested and were correctly diagnosed. This result indicates that discrimination of 47, XYY from 46, XY individuals is not possible using the dermal patterns examined here. The data of this survey confirm the variability of dermal findings in 47.XYY individuals reported by others. The data do not agree, however, with reports of significant differences between 47.XYY and 46, XY individuals in the total finger ridge count, the palmar a‐b ridge width and count, and the distal sole hypothenar area. These results indicate that the extra Y chromosome does not significantly affect the dermal patterns of 47, XYY patients.

Evaluation of Dermal Patterns in the Diagnosis of the Down Syndrome by Predictive Discrimination

Variations in dermal patterns have been reported between the sexes and among ethnic groups. The hypothesis that our diagnostic scoring method for Down syndrome overrides such variations was tested. A