The effects of frequent nocturnal home hemodialysis: the Frequent Hemodialysis Network Nocturnal Trial.

Prior small studies have shown multiple benefits of frequent nocturnal hemodialysis compared to conventional three times per week treatments. To study this further, we randomized 87 patients to three times per week conventional hemodialysis or to nocturnal hemodialysis six times per week, all with single-use high-flux dialyzers. The 45 patients in the frequent nocturnal arm had a 1.82-fold higher mean weekly stdKt/V(urea), a 1.74-fold higher average number of treatments per week, and a 2.45-fold higher average weekly treatment time than the 42 patients in the conventional arm. We did not find a significant effect of nocturnal hemodialysis for either of the two coprimary outcomes (death or left ventricular mass (measured by MRI) with a hazard ratio of 0.68, or of death or RAND Physical Health Composite with a hazard ratio of 0.91). Possible explanations for the left ventricular mass result include limited sample size and patient characteristics. Secondary outcomes included cognitive performance, self-reported depression, laboratory markers of nutrition, mineral metabolism and anemia, blood pressure and rates of hospitalization, and vascular access interventions. Patients in the nocturnal arm had improved control of hyperphosphatemia and hypertension, but no significant benefit among the other main secondary outcomes. There was a trend for increased vascular access events in the nocturnal arm. Thus, we were unable to demonstrate a definitive benefit of more frequent nocturnal hemodialysis for either coprimary outcome.

Managing research: the retrospective study. Expanding the role of the medical record department.

The medical record department plays an important role in supplying information for a variety of hospital functions. That role traditionally includes compiling demographic data and diagnosis and procedure indexes. The medical record professional is well-qualified to offer expanded informational services encompassing the management of research studies, and thus contribute to the advancement of medicine. This article describes how Cleveland Clinic Foundation's medical record department manages retrospective studies. The authors offer suggestions for other medical record professionals interested in expanding their roles in clinical research.

Stimulation and inhibition of human mammary epithelial cell duct morphogenesis in vitro.

We previously determined that normal human mammary epithelial cells (HMECs) placed on the basement membrane-like substance Matrigel form structures, whereas malignant breast cells do not (1). In the present study, we determined that the structures formed by normal cells on Matrigel resembled breast ducts in vivo by electron microscopy, and the process of their formation recapitulated what is known of duct formation in vivo. We therefore used this model to study less well-understood aspects of breast morphogenesis. Two priming signals appeared necessary for initiation of morphogenesis: one provided by the Matrigel and one by the cells in an autocrine fashion. Evidence for this included diminished duct formation by cells plated low-concentration Matrigel or at low cell densities, and the reversal of the latter by conditioned medium from high-density cells on Matrigel. Antibodies to bFGF inhibited morphogenesis, suggesting a stimulatory autocrine role for this factor, and antibodies to TGF-beta 1 stimulated duct formation, suggesting an inhibitory autocrine role. Added TGF-beta 1 abolished morphogenesis and stimulated normal cells to wander through Matrigel as do malignant cells. Conditioned medium from normal cells did not stimulate malignant cells to form ducts, but conditioned medium from tumor cells diminished normal morphogenesis, suggesting that malignant cells secrete an inhibitor of morphogenesis.