A COST COMPARISON OF MEDICAL MANAGEMENT AND TRANSURETHRAL NEEDLE ABLATION FOR TREATMENT OF BENIGN PROSTATIC HYPERPLASIA DURING A 5-YEAR PERIOD

PURPOSE

We performed an analysis comparing the cost of medical management with TUNA therapy for a 5-year period.

MATERIALS AND METHODS

Published costs for tamsulosin, finasteride, transurethral needle ablation (TUNA, Medtronic, Inc., Minneapolis, Minnesota) and transurethral resection of the prostate were used to construct a cost analysis model comparing medication with TUNA. The model analyzed monotherapy with an alpha-blocker (tamsulosin) and a 5alpha-reductase inhibitor (finasteride), combination therapy using both medications, and a mixed scenario using monotherapy and combination therapy. Published data were used to estimate the rate of surgical intervention in patients initially treated with medications or TUNA.

RESULTS

Tamsulosin monotherapy was less expensive than TUNA for 5 years ($3,485 for tamsulosin vs $4,811 for TUNA year 5). Finasteride monotherapy reaches a break-even point with TUNA during year 5 ($4,867 for finasteride vs $4,811 for TUNA). Combination therapy reaches a break-even point with TUNA after approximately 2 years 7 months of treatment ($4,515 for combination therapy vs $4,572 for TUNA) and the mixed scenario breaks even with TUNA at approximately year 4 ($4,696 for medical management vs $4,645 for TUNA).

CONCLUSIONS

The TUNA procedure compares favorably to combination medical therapy for the treatment of benign prostatic hyperplasia on a cost basis. alpha-Blocker monotherapy is less costly than TUNA while 5alpha-reductase inhibitor monotherapy is approximately equivalent to TUNA for 5 years. The TUNA procedure is less expensive than combination medical management for 5 years, with a break-even point at approximately 2 years 7 months.

An Alternate Core 2 β1,6-N-Acetylglucosaminyltransferase Selectively Contributes to P-Selectin Ligand Formation in Activated CD8 T Cells

Core 2 beta1,6-N-acetylglucosaminyltransferase (C2GlcNAcT) synthesizes essential core 2 O-glycans on selectin ligands, which mediate cell-cell adhesion required for lymphocyte trafficking. Although gene-deletion studies have implicated C2GlcNAcT-I in controlling selectin ligand-mediated cell trafficking, little is known about the role of the two other core 2 isoenzymes, C2GlcNAcT-II and C2GlcNAcT-III. We show that C2GlcNAcT-I-independent P-selectin ligand formation occurs in activated C2GlcNAcT-I(null) CD8 T cells. These CD8 T cells were capable of rolling under shear flow on immobilized P-selectin in a P-selectin glycoprotein ligand 1-dependent manner. RT-PCR analysis identified significant levels of C2GlcNAcT-III RNA, identifying this enzyme as a possible source of core 2 enzyme activity. Up-regulation of P-selectin ligand correlated with altered cell surface binding of the core 2-sensitive mAb 1B11, indicating that CD43 and CD45 are also physiological targets for this alternate C2GlcNAcT enzyme. Furthermore, C2GlcNAcT-I-independent P-selectin ligand induction was observed in an in vivo model. HY(tg) CD8 T cells from C2GlcNAcT-I(null) donors transferred into male recipients expressed P-selectin ligand in response to male Ag, although at reduced levels compared with wild-type HY(tg) CD8 T cells. Our data demonstrate that multiple C2GlcNAcT enzymes can contribute to P-selectin ligand formation and may cooperate with C2GlcNAcT-I in the control of CD8 T cell trafficking.

A directed screen for genes involved in Drosophila blood cell activation

An attack by a parasitic wasp activates a vigorous cellular immune response in Drosophila larvae. This response is manifested by an increased number of circulating cells, the hemocytes, and by the appearance of a specialized class of hemocyte, the lamellocytes, which participate in the encapsulation and killing of the parasite. To study the molecular mechanisms of this response, we have overexpressed different genes in the hemocytes, by using the GAL4-upstream activating sequence system and a hemocyte-specific Hemese-GAL4 driver. Multiple transgenes were tested, representing several important signaling pathways. We found that the proliferation response and the activation of lamellocyte formation are independent phenomena. A drastic increase in the number of circulating hemocytes is caused by receptor tyrosine kinases, such as Egfr, Pvr, and Alk, as well as by the downstream signaling components Ras85D and pointed, supporting the notion that the Ras-mitogen-activated protein kinase pathway regulates hemocyte numbers. In the case of Pvr and Alk, this phenotype also is accompanied by lamellocyte formation. By contrast, constitutively active hopscotch and hemipterous give massive activation of lamellocyte formation with little or no increase in total hemocyte numbers. This finding indicates that both the Jak/Stat and the Jun kinase pathways affect lamellocyte formation. Still other signals, mediated by aop(ACT), Toll(10b), and Rac1 expression, cause a simultaneous increase in lamellocyte and total cell numbers, and the same effect is seen when WNT signaling is suppressed. We conclude that the activation of a cellular response is complex and affected by multiple signaling pathways.

Validation of the FAMACHA© eye color chart for detecting clinical anemia in sheep and goats on farms in the southern United States

Recent studies on sheep and goat farms in the southern United States indicate that multiple-anthelmintic resistance in Haemonchus contortus is becoming a severe problem. Though many factors are involved in the evolution of resistance, the proportion of the parasite population under drug selection is believed to be the single most important factor influencing how rapidly resistance develops. Therefore, where prevention of resistance is an important parallel goal of worm control, it is recommended to leave a portion of the animals untreated. Recently, a novel system called FAMACHA was developed in South Africa, which enables clinical identification of anemic sheep and goats. When H. contortus is the primary parasitic pathogen, this system can be applied on the farm level to reduce the number of treatments administered, thereby increasing the proportion of the worm population in refugia. Since most studies validating the FAMACHA method have been performed in South Africa, it is important that the method be tested in other regions before its use is broadly recommended. We performed a validation study of FAMACHA by testing the system in sheep (n = 847) and goats (n = 537) of various breeds and ages from 39 farms located in Arkansas, Georgia, Louisiana, Florida, and the US Virgin Islands. The color of the ocular conjunctiva of all animals were scored on a 1-5 scale using the FAMACHA card, and blood samples were collected from each animal for determination of packed cell volume (PCV). Fecal samples were also collected from a majority of the animals tested for performance of fecal egg counts (FEC). Correlations between PCV and eye scores, PCV and FEC, and FEC and eye scores were all highly significant for both sheep and goats (P < 0.001). Data for both FAMACHA scores and PCV were evaluated using two separate criteria for anemia: eye score values of 3, 4 and 5 or 4 and 5, and PCV values of < or =19 or < or =15 were considered anemic. Specificity was maximized when eye score values of 4 and 5 were considered anemic and PCV cut off for anemia was < or =19, but sensitivity was low. In contrast, sensitivity was 100% for both sheep and goats when eye score values of 3, 4 and 5 were considered anemic and PCV cut off was < or =15, but specificity was low. In both sheep and goats, predictive value of a negative was greater than 92% for all anemia and eye score categories, and was greater than 99% for both eye score categories when an anemia cutoff of < or =15 was used. Predictive value of a positive test was low under all criteria indicating that many non-anemic animals would be treated using this system. However, compared to conventional dosing practices where all animals are treated, a large proportion of animals would still be left untreated. These data indicate that the FAMACHA method is an extremely useful tool for identifying anemic sheep and goats in the southern US and US Virgin Islands. However, further studies are required to determine optimal strategies for incorporating FAMACHA-based selective treatment protocols into integrated nematode control programs.

Conformational stability from variable temperature infrared spectra of krypton solutions, ab initio calculations, vibrational assignment, and r0 structural parameters of 1,3-difluoropropane

The infrared spectra (3200-400 cm(-1)) of krypton solutions of 1,3-difluoropropane, FCH2CH2CH2F, at variable temperatures (-105 to -150 degrees C) have been recorded. Additionally, the infrared spectra (3200-50 cm(-1)) of the gas and solid have been recorded as well as the Raman spectrum of the liquid. From a comparison of the spectra of the fluid phases with that in the solid, all of the fundamental vibrations of the C2 conformer (gauche-gauche) where the first gauche indicates the form for one of the CH2F groups and the second gauche the other CH2F, and many of those for the C1 form (trans-gauche) have been identified. Tentative assignments have been made for a few of the fundamentals of the other two conformers, i.e. C2v (trans-trans) and Cs (gauche-gauche'). By utilizing six pairs of fundamentals for these two conformers in the krypton solutions, an enthalpy difference of 277 +/- 28 cm(-1) (3.31 +/- 0.33 kJ mol(-1)) has been obtained for the C2 versus C1 conformer with the C2 conformer the more stable form. For the C2v conformer, the enthalpy difference has been determined to be 716 +/- 72 cm(-1) (8.57 +/- 0.86 kJ mol(-1)) and for the Cs form 971 +/- 115 cm(-1) (11.6 +/- 1.4 kJ mol(-1)). It is estimated that there is 64 +/- 3% of the C2 form, 34 +/-3% of the C1 form, 1% of the C2v form and 0.6% of the Cs conformer present at ambient temperature. Equilibrium geometries and total energies of the four stable conformers have been determined from ab initio calculations with full electron correlation by the perturbation method to second order as well as by hybrid density functional theory calculations with the B3LYP method using a number of basis sets. The MP2 calculations predict the C1 conformer stability to be slightly higher than the experimentally determined value whereas for the C2v and Cs conformers the predicted energy difference is much larger than the experimental value. The B3LYP calculations predict a better energy difference for both the C1 and C2v as well as for the Cs conformers than the MP2 values. A complete vibrational assignment is proposed for the C2 conformer and many of the fundamentals have been identified for the C1 form based on the force constants, relative intensities and rotational-vibrational band contours obtained from the predicted equilibrium geometry parameters. By combining previously reported rotational constants for the C2 and C1 conformers with ab initio MP2/6-311 + G(d, p) predicted parameters, adjusted r0 parameters have been obtained for both conformers. Comparisons are made with the parameters obtained for some other molecules containing the FCH2 group. The spectroscopic and theoretical results are compared to the corresponding properties for some similar molecules.

Dosimetry of small electron fields shaped by lead

Electron radiotherapy fields are commonly used to treat superficial cancers. Field shaping can be achieved by placing lead on the patient surface to minimise the dose to surrounding areas. However, significant dosimetry changes under high density material edges for electron fields have been reported in the literature. This project evaluated the dosimetry of small dimension electron fields shaped with lead placed on the surface. Comparisons were made between circular lead cutouts placed on the skin and low melting point alloy cutouts placed in an applicator. Depth doses, profiles and output factors were measured using a diode detector in a water phantom. Film was also used to determine surface dose delivered when the lead cutouts were placed on the surface. Minimal differences were observed between the different setups for the depth dose curves, although significant differences were seen in the penumbra and the surface doses. The penumbra is smaller for the lead cutouts placed on the surface, however, significant dose increases at the edge of the field were observed for larger fields and energies; this may result in undesirable clinical effects.

Microscopic analysis of the cellular events during scatter factor/hepatocyte growth factor-induced epithelial tubulogenesis

Scatter factor/hepatocyte growth factor (SF/HGF), a large multifunctional polypeptide growth and motility factor, is known to play important roles during embryonic development, adult tissue growth and repair. In an established three-dimensional type I collagen model, SF/HGF induces Madin-Darby canine kidney (MDCK) epithelial cysts to form long, branching tubules (tubulogenesis). In addition, the composition of the surrounding extracellular matrix (ECM) has been shown to modulate SF/HGF-induced morphogenesis, where tubulogenesis was completely abrogated in Matrigel basement membrane. Many cellular events that occur during SF/HGF-mediated remodelling, and its modulation by the ECM, remain unclear. We have investigated these mechanisms through microscopic examination of the time-course of SF/HGF-induced responses in MDCK cysts cultured in type I collagen or Matrigel. We found that early responses to SF/HGF were matrix-independent. Changes included increased paracellular spacing between normally closely apposed lateral membranes, and the formation of filopodial processes, indicating a partial motile response. Cell-cell contact was maintained, with the persistence of cell junctions. Therefore, while one or a number of ECM components are preventing SF/HGF-primed cells from undergoing an invasive and/or migratory programme, non-permissive matrices are not preventing SF/HGF signalling to the cell. Later matrix-dependent responses, which occurred in type I collagen but not Matrigel, included the formation of basal protrusions that comprise two or more neighbouring cells, which extend to form nascent tubules. Modified polarity of cells comprising the basal protrusions was evident, with a marker for the apical membrane being found in the same region as adherens junctions and desmosomes, typically localized at lateral membranes. We propose a model for SF/HGF-induced tubulogenesis in which tubules form from basal protrusions of adjacent cells. This mechanism of in vitro tubule formation has many similarities to reported in vivo epithelial tubulogenesis.

Modulation of O-Glycans and N-Glycans on Murine CD8 T Cells Fails to Alter Annexin V Ligand Induction by Galectin 1

Thymic negative selection and contraction of responding T cell oligoclones after infection represent important cell ablation processes required for maintaining T cell homeostasis. It has been proposed that galectin 1 contributes to these processes through interaction with lactosyl sequences principally on cell surface glycoproteins bearing core 2 (C2GnT1)-branched O-glycans. According to this model, specific T cell surface proteins cross-linked by galectin 1 induce signaling, ligand redistribution, and apoptosis in both immature thymocytes and activated T cells. The influence of lactosyl residues contained in branched O-glycans or complex N-glycans on galectin 1 binding and induction of annexin V ligand in murine CD8 T cells was assessed. Neither galectin binding nor galectin-induced expression of annexin V ligand was perturbed under conditions in which: 1) C2GnT1 activity was differentially induced by CD8 T cell activation/culture with IL-2 vs IL-4; 2) activated CD8(+) T cells lacked C2GnT1 expression; or 3) complex N-glycan formation was blocked by swainsonine. The maintenance of galectin 1 binding and induced annexin V expression under conditions that alter lactosamine abundance on O- or complex N-glycans suggest that galectin 1-mediated apoptosis is neither a simple function of fluctuating C2GnT1 activity nor a general C2GnT1-dependent mechanism underlying contraction of CD8 T cells subsequent to activation.

Circular versus longitudinal myometrial contractile response to selective tachykinin receptor agonists in rat

This study compared the nature and magnitude of the contractile response produced in vitro by selective NK1, NK2 and NK3 tachykinin receptor agonists in circularly and longitudinally oriented strips of myometrium from ovariectomised and ovariectomised oestrogen-treated rats. The nature of the responses produced upon stimulation of the tachykinin receptors varied between the different myometrial preparations and the hormonal environment from which the tissue was taken. Variations included: (i) sustained contraction until washout of agonist; (ii) biphasic contraction until washout of agonist; and (iii) monophasic contraction. The major differences in magnitude of contractions were seen in preparations from oestrogen-treated animals in which responses to stimulation of all tachykinin receptors were reduced in comparison to preparations from non-oestrogen treated animals. Furthermore, the responses in circularly oriented myometrium preparations from oestrogen-treated animals were all markedly reduced compared to responses in longitudinally oriented myometrium preparations. These results suggest that the tachykinin receptors in longitudinally and circularly oriented myometrial layers are differentially regulated, especially in tissue isolated from an oestrogen-dominated environment.

Standard measures of executive function in predicting instrumental activities of daily living in older adults

OBJECTIVE

The purpose of this study was to examine the ability of specific, commonly used neuropsychological tests of executive function to predict functional status among a group of elderly subjects.

METHODS

Fifty study participants underwent a brief neuropsychological evaluation of executive functions and assessment of instrumental activities of daily living (IADL).

RESULTS

A multiple stepwise regression analysis indicated that executive function tests accounted for 54% of the variance in functional status. An examination of the standardized regression coefficients revealed that Trail Making Test-Part B and the Wisconsin Card Sorting Test were the only two of the five executive function tests that significantly predicted functional status. These executive function measures contributed significantly to the prediction of functional status even after statistically controlling for age, sex, and education.

CONCLUSION

Thus, the common clinical measures of executive function are useful in predicting functional status in older adults.

Regulation of antibacterial and antifungal innate immunity in fruitflies and humans

Insects have been very successful in adapting to their environment, and the ability of the insect immune system to detect and elicit the appropriate response against various invading pathogens has helped in this success. Unlike the vertebrate immune system, which consists of both innate and adaptive components, insect immunity probably consists entirely of an innate immune response, as no evidence of an adaptive response has been found. The innate immune response is described as either a reaction against "lack of self," or the interaction between host germline-encoded receptors and molecules unique to a particular class of invading organisms. Once the invading organism is recognized, the host immune response can be activated via signaling pathways that lead to the appropriate reaction. This review endeavors to put forth how through genetic, molecular, and biochemical studies of the fruit fly Drosophila melanogaster, as well as other insects, it is now understood that aspects of the insect and vertebrate innate immune system are very similar.

IL-2, -4, and -15 differentially regulate O-glycan branching and P-selectin ligand formation in activated CD8 T cells

The glycosyltransferase core 2 beta1-6 N-acetylglucosaminyl transferase (C2GnT1 or C2GlcNAcT1) is responsible for formation of branched structures on O-glycans present on cell surface glycoproteins. The O-glycan branch created by C2GnT1 is physiologically important insofar as only this structure can be extended and modified to yield P-selectin ligands that promote initial interactions between extravasating lymphocytes and endothelia. In mature T cells, C2GnT1 activity is thought to be induced as an intrinsic consequence of T cell activation. Through analysis of C2GnT1-dependent epitopes on CD43 and CD45RB we have found that in activated CD8(+) T cells expression of C2GnT1 was dependent upon exposure to specific cytokines rather than being induced as a direct consequence of activation. Activated CD8(+) cells became receptive to strong induction of C2GnT1 expression and P-selectin ligand expression in response to IL-2, moderate induction by IL-15, and minimal induction in response to IL-4. Our observations clarify the relationship between T cell activation and C2GnT1 expression, demonstrate the differential impact of distinct cytokines on expression of C2GnT1 activity and P-selectin ligand, and reinforce the concept that the cytokine milieu subsequent to activation can influence adhesion systems that dictate lymphocyte homing properties.

Pasture management effects on diet composition and cattle performance on continuously stocked rhizoma peanut-mixed grass swards

In Florida, rhizoma peanut (RP; Arachis glabrata Benth.), a tropical legume, combines the attributes of excellent nutritive value, competitive ability with tropical grasses, and high animal performance. The objective of this study was to determine the effects of spring N fertilization (0 vs 35 kg/ha) and summer stocking rate (1.5 and 2.5 bulls/ha) on herbage mass, nutritive value, herbage allowance, and diet botanical composition of grazed RP-grass swards and their interaction with growth and development of bulls (Senepol, and Brahman or Angus). The study was conducted in 1995 and 1996 at the USDA, ARS, Subtropical Agriculture Research Station in Brooksville, FL. Nitrogen was applied in April of each year, and all pastures were stocked with 1.5 bulls/ha until approximately July of each year, when stocking rate was increased on half the pastures to 2.5 bulls/ha. Herbage mass (HM, kg/ha), herbage allowance (HA, kg/kg BW), nutritive value (CP and in vitro organic matter digestibility [IVOMD]), and diet botanical composition (fecal microhistological) readings were determined. Animal measurements included total and seasonal (spring vs summer), ADG, hip height (cm), scrotal circumference (SC, cm), and plasma urea nitrogen (PUN, mg/dL). Herbage mass (3.0 +/- 0.12 Mg/ha and 3.4 +/- 0.13 Mg/ha in 1995 and 1996, respectively) was not affected by nitrogen fertilization or stocking rate but was affected by season (P < 0.05) due to increased plant growth rate associated with summer rainfall. Stocking rate did affect herbage availability, but it never fell below 3 kg/kg BW, indicating herbage availability was never limiting. Crude protein (200 to 140 g/kg) and IVOMD (650 to 540 g/kg) were not affected by treatment, but declined (P < 0.001) from spring until fall. Treatments also had no effect on diet botanical composition. Summer ADG averaged about 0.2 kg/d lower than spring ADG, due, in part, to seasonal declines in nutritive value. Because herbage allowance was never limiting, full-season ADG was not affected by stocking rate or N fertilization and averaged 0.61 +/- 0.03 and 0.60 +/- 0.02 kg/d in 1995 and 1996, respectively. There were season x breed interactions (P < 0.05) for ADG due to greater declines during the summer for Angus than for Senepol or Brahman. There were no differences in final BW, SC, BCS, hip height, or PUN due to treatments, but breed differences were noted (P < 0.05) for all measures except BCS.

Dysfluency and involuntary movements: a new look at developmental stuttering

Studies using modern imaging techniques suggest that, in developmental stuttering, there is dysfunction within the cortical and subcortical areas of the motor control system wider than that pertaining to speech motor control alone. If this is the case, one might expect motor deficits extending beyond and unrelated to the production of speech in people who stutter. This study explored this proposal by investigating the presence and characteristics of involuntary movements accompanying stuttering. Sixteen adults with developmental stuttering and 16 controls matched for age and sex were audio-videotaped during 5 minutes of conversational speech and reading a passage of 350 words. Audio-data were examined for dysfluencies. Movements of the face, head and upper body considered involuntary and not part of normal facial expression or gesture and not part of the mechanics of speech were identified and described from muted video-data. Subjects who stuttered had a higher proportion of classic (within-word) dysfluencies accompanied by involuntary movements (IMs) than controls during speech (24.4% vs. 4.5%, p = .054) and reading (28.6% vs. 4.9%, p = .033). There was no difference in proportion of classic dysfluencies accompanied by IMs between speech and reading for either group. IMs were also seen in both groups during fluent speech, with a similar incidence during free speech (3.9% vs. 3.0%, NS) but a greater incidence in the subjects who stuttered during reading (2.4% vs. 0.8%, p = .03). In contrast, there was no difference between the two groups for IMs accompanying normal (between-word) dysfluencies. This suggests that classic and normal dysfluency and their accompanying IMs have different etiologies. The notion that stuttering and IMs are due to altered function in a motor control system wider than that of speech motor control alone is supported by a higher incidence of IMs in people who stutter during both classic dysfluencies and fluent speech.

A clinical minimum data set for primary dental care

OBJECTIVE

To achieve consensus within primary dental care on the contents of a clinical minimum data set to measure oral health status.

DESIGN

Using the Delphi process a simple random sample of 30 LDCs and 10 CDS services in England were asked to rank a list of existing clinical indicators in order of their perceived importance as a means of measuring oral health. A nominated panel representing the stakeholder organisations of primary dental care reviewed this ranking and identified a core group of clinical indicators to be included in a clinical minimum data set.

RESULTS

An 80 percent response rate to the Delphi process was achieved. Consensus was reached on a core group of 10 indicators, which can provide information on patient's perceptions of pain, function and appearance, and professional measurements of caries, teeth present, periodontal disease, oral sepsis, presence of mucosal pathology and tooth wear.

CONCLUSIONS

A representative sample of primary care dentists in England and the key representative organisations of primary dental care achieved consensus on the contents of a clinical minimum data set to record oral health status in primary dental care. This is a first step in standardising the measurement of oral health status across primary care.

Normal endothelial function after meals rich in olive or safflower oil previously used for deep frying

BACKGROUND AND AIM

Polyunsaturated fats are more susceptible to oxidation during heating than monounsaturated fats but their effects on endothelial function when heated are unknown. The aim of this study was to compare the effect of meals rich in heat-modified safflower and olive oils on postprandial flow-mediated endothelium-dependent dilation (EDD) in healthy men.

METHODS AND RESULTS

Flow-mediated EDD and glyceryltrinitrate-induced endothelium-independent dilation of the brachial artery were investigated in 14 subjects before and 4 hours after meals rich in olive oil and safflower oil used hourly for deep-frying for 8 hours in a double-blind crossover study design. There were high levels of lipid oxidation products (peroxides and carbonyls) in both heated oils. Plasma triglycerides were markedly increased at 4 hours after heated olive oil (1.26 +/- 0.43 vs 2.06 +/- 0.97 mmol/L) and heated safflower oil (1.44 +/- 0.63 vs 1.99 +/- 0.88 mmol/L). There was no change in EDD between fasting and postprandial studies and the response during the postprandial period was not significantly (p = 0.51) different between the meals (heated olive oil: 4.9 +/- 2.2% vs 4.9 +/- 2.5%; heated safflower oil: 5.1 +/- 3.1% vs 5.6 +/- 3.4%).

CONCLUSIONS

Meals rich in olive and safflower oils previously used for deep frying and containing high levels of lipid oxidation products increase postprandial serum triglycerides without affecting endothelial function. These findings suggest that relatively short-term use of these vegetable oils for frying may not adversely affect postprandial endothelial function when foods containing the heat-modified oils are consumed.

Vitamin C improves endothelial dysfunction in renal allograft recipients

BACKGROUND

Endothelial function is impaired in renal allograft recipients but the effects of antioxidant vitamin therapy on endothelial function in such patients is unknown.

METHODS

Thirteen renal allograft recipients were randomized to vitamin C or placebo in a double blind cross-over study design. Flow-mediated endothelium-dependent dilation and glyceryltrinitrate-induced endothelium-independent dilation of the brachial artery were assessed before and 2 h after oral administration of 2 g vitamin C or placebo.

RESULTS

Plasma vitamin C levels increased from 33.5+/-17.0 micromol/l to 98.8+/-60.2 micromol/l after treatment (P=0.0001). Endothelium-dependent dilation improved (from 1.6+/-2.6 to 4.5+/-2.5%) after vitamin C administration but was unchanged after placebo (1.9+/-1.5 to 1.8+/-2.5%; P=0.003 for vitamin C vs placebo). There was no significant change in endothelium-independent dilation in response to vitamin C. Vitamin C was also associated with a significant increase in the lag time in dilute serum oxidation (P=0.001).

CONCLUSIONS

Vitamin C acutely improves flow-mediated, endothelium-dependent dilation and increases the resistance of lipoproteins in dilute serum to oxidation in renal transplant recipients.