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Biomedical subjects

D Helbig

Publications and source records attributed to D Helbig.

At least 19 recordsLinked to original sources
PubMed1997

Does creatinine adjustment of urinary pregnanediol glucuronide reduce or introduce measurement error?

Correlation between urinary pregnanediol and serum progesterone measurements and the influence of age, race, smoking and urinary creatinine adjustment was determined during the luteal phase of the menstrual cycle in 175 volunteers. A decline in serum progesterone was observed with increasing age. Mean baseline urinary creatinine declined with increasing age in non-smokers and was not affected by race or baseline weight. An excellent correlation between urinary pregnanediol glucuronide and serum progesterone levels existed except when urinary pregnanediol concentrations were adjusted using creatinine measurements in older individuals. Adjustment of urinary pregnanediol glucuronide concentration using creatinine measurement is therefore discouraged.

Adult↗
PubMed1996

Predictors of ovarian steroid secretion in reproductive-age women.

During the baseline period (1985-1988) of a prospective study, midcycle and luteal-phase estrogens and progestins were measured in 175 healthy women aged 21-36 years with spontaneous, cyclic menses in Brooklyn, New York. Subjects contributed daily first-morning urine specimens and three blood specimens during a single menstrual cycle monitored by basal body temperature. Hormone levels were compared according to age, race, and levels of known or suspected breast cancer risk factors. Late age at menarche was associated with increased urinary and serum progestin levels. Increased body weight was associated with decreased progestin levels, even in ovulatory women. Neither weight nor age at menarche was related to estrogen levels. Cigarette smoking was associated with decreased midcycle and luteal-phase estradiol levels. No other factors were associated with differences in any of the hormones measured either midcycle or during the luteal phase, despite good statistical power to detect moderate differences. Sources of individual variability in ovarian steroid levels remain unexplained. These data do not support hypotheses that breast cancer risk factors act through an effect on ovarian hormones during the middle reproductive years.

Adult↗
PubMed1990

Regeneration of adsorbed and covalently immobilized antibodies on solid phases for immunoassay.

A technique for the reproducible re-use of antibody-coated solid phases for immunoassays is described. The method based on the dissociation of the antigen-antibody complexes. Two different procedures, using glycine buffer (pH 2.3) or ethanolamine, were developed. More than ten immunoassay cycles can be realized with the same antibody-coated microtitre plates. These procedures were tested with competitive and sandwich immunoassays, monoclonal and polyclonal antibodies, and a commercial immunoassay kit.

Adsorption↗
PubMed1980

[Duodenal stenosis and duodenal atresia in neonates (author's transl)].

Of 129 neonates including 38 premature births who were operated for duodenal atresia or stenosis, 101 survived. 28 children died, not as a result of the operation but primarily from accompanying deformities, or because of subarachnoid and pulmonary hemorrhages associated with coagulation disturbances. 2 babies died of sepsis. 80 of the 101 surviving patients could be surveyed through a questionnaire action. 24 of these children were also examined clinically and radiologically. No noteworthy complaints could be recorded even 16 years after the operation. A retarded development seen during the first 5 years seems to have been well compensated subsequently under suitable living conditions so that the prognosis for later life can be considered favorable.

Abnormalities, Multiple↗
PubMed1975

[Internal fixation in the presence of soft-tissue damage in childhood (author's transl)].

Internal fixation is considered for the treatment of 10 percent at most of all fractures that occur in childhood. Only minimal fixation should be applied, to avoid the induction of an epiphyseal lesion in addition to the original fracture. Internal fixation allowing stability during weight-bearing or exercise immediately is not necessary in a child. Concomitant soft-tissue damage hardly affects internal fixation in childhood, except in the case of unstable reduction when there is extensive soft-tissue damage.

Age Factors↗