Can family attributes explain the racial disparity in living kidney donation?

BACKGROUND: Living donation is a safe, effective treatment for patients with end-stage renal disease (ESRD), yet rates of live kidney donation remain low. Potential transplant recipients may be more inclined to ask a family member for a living donation if they feel familial closeness. METHODS: The FACES II and the Living Organ Donor Survey were administered to patients attending pretransplant education to assess individual perceptions of family structure and willingness to request a living kidney donation from a family member. RESULTS: A total of 328 potential transplant recipients were included in the study: 200 (61%) African American and 128 (39%) Caucasian. Approximately half were willing to ask for a living donation. Individual's perception of family cohesion, adaptability, and type as measured by FACES II showed most families were mid-range with optimal cohesion and adaptability. Family cohesion and adaptability showed no association with being willing to request a live donation, but those single/never married were only half as likely to ask for donation (odds Ratio [OR] 0.51; 95% confidence interval [CI] 0.31-0.86, P = .01). Lower education (beta = -0.49) and unmarried status (beta = -0.31) predicted a lower cohesion score. CONCLUSION: Family type, cohesion, and adaptability showed no differences across race and was not related to the potential recipient's willingness to ask for a live donation. Although responses by race did not differ, an important finding showed that only half of ESRD patients are willing to ask for a live organ donation, and those patients that were single/never married were less likely to ask for a living donation. Research surrounding this reluctance is warranted.

Spatiotemporal messenger ribonucleic acid expression of ovarian tissue inhibitors of metalloproteinases throughout the rat estrous cycle.

The tissue inhibitors of metalloproteinases (TIMPs) within the ovary closely regulate the matrix metalloproteinases, enzymes capable of degrading components of the extracellular matrix. The purpose of this study was to examine the spatial and temporal messenger RNA (mRNA) expression of the TIMPs in the ovaries of normally cycling rats. Ovaries were collected at 1100 h on each day of the 4-day estrous cycle, and TIMP mRNA expression was examined by Northern blot, RT-PCR, or in situ hybridization. TIMP-1 mRNA levels were significantly higher on estrus than on any other day. Although the 1.0-kb TIMP-2 transcript did not change across the cycle, the 3.5-kb transcript decreased significantly between metestrus and diestrus. Expression of TIMP-3 mRNA decreased significantly between proestrus and estrus. TIMP-1, TIMP-2, and TIMP-3 mRNAs were primarily localized to the theca, stroma, and corpora lutea (CL) on all days of the cycle, but with distinct cyclic changes. Thecal expression of TIMP-1 and TIMP-2 mRNAs was especially high immediately before and after ovulation. TIMP-1 and TIMP-3 mRNAs, which were low to undetectable in the granulosa cells of preovulatory follicles, were greatly increased in the luteinizing cells of newly forming CL on estrus. Although the presence of TIMP-1 mRNA in the granulosa cells of preovulatory follicles by in situ hybridization was near background levels, it was specifically identified in granulosa cells of follicles on all days of the cycle using laser capture microdissection and RT-PCR. Both TIMP-2 and TIMP-3 transcripts were up-regulated in luteinized follicles on proestrus and were present throughout the cycle in regressing CL. In summary, the unique and dynamic expression patterns of the TIMPs suggest that they have important, yet distinct, functions in the ovary. The high levels of TIMP-1 mRNA in the CL on estrus indicate a likely role for this inhibitor in luteal formation. The presence of TIMP-2 mRNA in regressing CL suggests an involvement in luteal demise, whereas TIMP-3 may play a role in the health of the follicle as well as in CL regression.

Oxytocin-neurophysin I mRNA abundance in equine uterine endometrium.

A positive-feedback loop between luteal oxytocin and uterine prostaglandin F2 alpha (PGF) is a major signal for luteolysis in ruminants. Likewise, uterine PGF causes luteolysis in mares, but the involvement of oxytocin in this process is unclear. We wanted: 1) to determine if the oxytocin-neurophysin I (OT-NP I) gene is transcribed into mRNA in the endometrium of mares; and, if so, 2) to analyze relative changes in abundance of endometrial OT-NP I mRNA throughout the estrous cycle and during early stages of pregnancy. Endometrial biopsies were obtained from nonbred mares during estrus, and 5, 10, and 15 d after ovulation (n = 3/d). Biopsies were also obtained from pregnant mares 10, 15, and 20 d after ovulation (n = 3/d). Relative amounts of OT-NP I and glyceraldehyde-3-phosphate dehydrogenase mRNA in endometrium were assessed by reverse transcription-polymerase chain reaction and Southern blotting. Endometrial OT-NP I mRNA abundance changed with day of the cycle or pregnancy, and levels at estrus were higher than at any other days examined. The OT-NP I mRNA levels were negatively correlated with serum progesterone across all days examined and positively correlated with serum estradiol in nonbred mares. The reverse transcription-polymerase chain reaction products for both OT-NP I and glyceraldehyde-3-phosphate dehydrogenase were cloned into vectors and sequenced. Each shared greater than 89% nucleotide and predicted amino acid identities with the respective human, bovine, ovine, and rat products. Uterine oxytocin may be involved in regulation of reproductive tract function during the estrous cycle and/or establishment of pregnancy in horses.

Effects of steroids on endometrial oxytocin mRNA production.

In this study, the roles of oestrogen and progesterone in the regulation of oxytocin gene expression in equine endometrium were examined. Anoestrous mares (n=19) were assigned randomly to one of the following treatment groups: control (vehicle control for 1 day; n=3); progesterone (250 mg progesterone per day for 6 days; n=4); oestradiol (5 mg beta-oestradiol 17-valerate per day for 6 days; n=4); oestradiol plus short duration progesterone (5 mg beta-oestradiol 17-valerate per day for 6 days followed by 250 mg progesterone per day for 6 days; n=4); and oestradiol plus long duration progesterone (5 mg beta-oestradiol 17-valerate per day for 6 days followed by 250 mg progesterone per day for 12 days; n=4). Jugular venous blood samples were obtained for oestrogen and progesterone radioimmunoassays. Endometrial biopsies were obtained and total RNA was extracted. Expression of mRNA for oxytocin and glyceraldehyde 3'-phosphate dehydrogenase was assessed by RT-PCR and Southern blotting. Oxytocin mRNA abundance was significantly higher (P < 0.05) in the oestrogen-treated group than in all other groups. These data demonstrate that oestradiol priming for 6 days upregulated expression of the endometrial oxytocin gene. Progesterone treatment for either 6 or 12 days after oestradiol priming returned oxytocin mRNA abundance to levels similar to those of controls.

Changes in equine endometrial oestrogen receptor alpha and progesterone receptor mRNAs during the oestrous cycle, early pregnancy and after treatment with exogenous steroids.

Two experiments were performed to determine changes in the abundance of oestrogen and progesterone receptor (ER alpha and PR) mRNAs in equine endometrium during the oestrous cycle and early pregnancy, and under the influence of exogenous steroids. In Expt 1, endometrial biopsies were obtained from non-mated mares during oestrus and at days 5, 10 and 15 after ovulation, and from pregnant mares at days 10, 15 and 20 after ovulation. There were overall effects of day on the abundance of ER alpha (P = 0.0001) and PR (P = 0.0014) mRNAs. The amount of ER alpha mRNA decreased at day 10 of pregnancy, and PR mRNA was reduced at day 5 in non-mated mares and at day 15 of pregnancy, compared with oestrous values. Experiment 2 was conducted to determine the effects of exogenous steroids on endometrial ER alpha and PR mRNAs. Endometrial biopsies were obtained from 19 anoestrous mares that had been treated with vehicle, oestradiol, progesterone, or oestradiol followed by progesterone for either a short or a long duration. The steroid treatment affected the abundance of ER alpha mRNA (P = 0.0420), which was higher (P < 0.05) in the oestradiol group than in the group treated with oestradiol followed by long duration progesterone. The steroid treatment did not affect the abundance of PR mRNA. These results demonstrate that the amount of steroid receptor mRNA changes with the fluctuating steroid environment in the uterine endometrium of cyclic and early pregnant mares, and that the duration of progesterone dominance may affect ER alpha gene expression. In addition, factors other than steroids may regulate ER alpha and PR gene expression in equine uterine endometrium.

Identification and initial characterization of calcyclin and phospholipase A2 in equine conceptuses.

For development to proceed normally, the appropriate genes must be expressed in the correct tissues and in the correct time frame. Knowledge of gene expression during development provides information about the changes taking place within the conceptus as well as possible reasons for pregnancy failure. However, little is known about gene expression during development in the equine conceptus. In this study, we examined differences in gene expression between day 12 and day 15 equine conceptuses by suppression subtractive hybridization. This technique was used to isolate transcripts that are more abundantly expressed in day 15 conceptuses compared to day 12 conceptuses. Between day 12 and 15 of pregnancy in horses, maternal recognition of pregnancy occurs, gastrulation is taking place, and mesoderm is beginning to form. Fifty cDNA clones were isolated, sequenced, and compared to known sequences in the GenBank database. Two cDNA clones identified that were of primary interest were calcyclin and phospholipase A2. Calcyclin is a calcium-binding protein of the S-100 protein family that has been found in mouse decidua and trophoblast. Calcyclin was found to be expressed in both day 12 and 15 equine conceptuses, with approximately a 30-fold increase in transcript abundance between days 12 and 15. Phospholipase A2 is an enzyme that cleaves phospholipids to release fatty acids and is involved in arachidonic acid release needed for prostaglandin, thromboxane, and leukotriene synthesis. Multiple forms of PLA2, that appear to be differentially regulated in day 12 and 15 conceptuses, were detected by northern blotting.

Multiple-dose pharmacokinetics of pentoxifylline and its metabolites during renal insufficiency.

OBJECTIVE: To characterize pentoxifylline (PTF) and metabolite disposition after multiple oral doses given two and three times a day to patients with renal dysfunction. DESIGN: An open-label, randomized, crossover, parallel group design. SETTING: Community-based clinical research center. PATIENT POPULATIONS: Subjects with renal function stratified based on 24-hour urinary creatine clearance (Clcr): group I = Clcr > 80 mL/min (n = 9); group II = Clcr 30-80 mL/min (n = 6); and group III = Clcr < 30 mL/min (n = 10). METHODS: PTF 400 mg bid or tid was administered on days 1-7 and 400 mg bid or tid was given on days 14-20 with a 1-week washout. Timed blood samples were taken on days 1, 7, and 20. Blood samples were analyzed for PTF and its metabolites (M-I, M-IV, M-V) by gas-liquid chromatography. MAIN OUTCOME MEASURES: Maximum plasma concentrations (Cmax), time to maximum concentration (tmax), average steady-state plasma concentration (CavgSS), and area under the plasma concentration-time curve at steady-state (AUCSS) were determined by visual and model independent methods. ANOVA, paired t-test, and linear regression were used with significance level set at p < 0.05. RESULTS: The ratio of PTF AUCSS (tid):AUCSS (bid) and M-I AUCSS (bid and tid) were not significantly different between the groups. Significant differences were found in M-IV and M-V Cmax, AUCSS, CavgSS, and AUCSS ratios (M-IV:PTF and M-V:PTF) between renal function groups (p < 0.05 for all). A change in dosage regimen from tid to bid resulted in significant changes in M-IV and M-V CavgSS for subjects with normal renal function and in those with moderate dysfunction, although not in subjects with severe renal dysfunction. CONCLUSIONS: Renal dysfunction did not cause significant accumulations of PTF or M-I after multiple bid and tid dosing, however, M-IV and M-V had significant accumulation in patients with renal impairment. Dosage reduction to 400 mg bid for patients with moderate renal impairment and 200-400 mg/d for severe renal impairment, as well as close clinical monitoring, seem prudent until the complex pharmacologic interactions of PTF and its metabolites can be further delineated.

Differential gene expression in day 12 and day 15 equine conceptuses.

Complex changes in gene expression must occur at the proper time and in the appropriate tissues for pregnancy to be successful. Therefore, research aimed at defining the regulation of gene expression in conceptuses is of critical importance. However, information on developmentally regulated changes in gene expression in horse conceptuses is sparse and inadequate. In the present study, suppression subtractive hybridization was used to identify genes that are expressed more highly at day 15 than on day 12 of gestation. This period encompasses maternal recognition of pregnancy and the beginning of mesoderm formation and gastrulation. Clones (n=50) were isolated, partially sequenced and the sequences obtained were compared with known sequences to determine their identity. Analysis of glyceraldehyde-3-phosphate dehydrogenase and alpha-fetoprotein (AFP) in subtracted and unsubtracted samples indicated a high efficiency of subtraction. Some of the genes identified included pregnancy-associated glycoprotein (PAG), fumarylacetoacetase, cytokeratins 8 and 18, and isocitrate and succinate dehydrogenases. Differential gene expression of PAG and AFP between days 12 and 15 was confirmed. PAG expression increased approximately 30 times and AFP expression increased at least 1000 times between days 12 and 15.