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Biomedical subjects

C D Christian

Publications and source records attributed to C D Christian.

36 records · Page 2Linked to original sources
PubMed1978

Urea and dilatation of the cervix.

The minimal elasticity of the uterine cervix has been related to its high collagen content. By interfering with cohesive forces that hold the collagen fiber bundle together, it is possible to diminish the physical strength of collagen. Urea has been used in collagen chemistry to dissociate collagen by interfering with hydrophobic linkages and hydrogen bonds. This results in a change of mechanical properties such as a decrease in tensile strength and an increase in elasticity. Basic studies of rat tail tendon demonstrated the additive effects of pH, concentration of urea, and temperature on the mechanical characteristics of collagen fibers. In vitro testing was performed using an injection of 30 per cent urea at pH 4. Serial measurements with a spring gauge instrument showed a reduction in cervical resistance. A cervical injection technique has been developed and toxicity of urea studied.

Animals↗
PubMed1978

Polyamines in amniotic fluid, plasma, and urine during normal pregnancy.

Polyamines have been implicated as markers of cell kinetic parameters. Putrescine and spermine were elevated in the urine of women with normal pregnancies. Particularly striking was the over 75-fold increase in spermine excretion. Putrescine was more than twofold that found for normal women. In several patients followed serially during pregnancy to assess the temporal pattern of the urinary excretion of polyamines, it was found that the highest levels of all three polyamines occurred at 12 weeks of gestation. In amniotic fluid, putrescine was higher prior to 30 weeks of gestation whereas spermidine was significantly higher at or beyond 30 weeks of gestation. Spermine was relatively high in both groups. Studies are ongoing to assess whether alterations from these normally elevated patterns will occur in the fluids of pregnant women at high risk for abnormal fetal development.

Amniotic Fluid↗
PubMed1978

Functional endometrial tissue with vaginal agenesis.

Vaginal agenesis in association with an intact and functioning or partially functioning uterus is not a well-described problem. The literature advocates attempting to preserve the uterus and surgically create a neovagina. Two patients are presented who suffered severe mobidity after the latter approach. We believe that there are three possibilities with patients who have functional endometrial tissue with vaginal agenesis: namely, an imperforate hymen, a transverse vaginal septum or complete vaginal agenesis with the absence or malformation of the cervix. If an imperforate hymen and transverse vaginal septum are ruled out, we believe it is the best interest of the patient to remove the Müllerian structures during the initial surgery.

Adolescent↗