The molecular basis of growth hormone action

Recent studies have begun to elucidate the molecular actions of growth hormone, a major regulator of somatic growth and metabolic functions. The cell surface growth hormone receptor, a member of the cytokine receptor superfamily, binds as a dimer to a single growth hormone molecule. Receptor dimerization precedes signal transduction, which is predominantly mediated by the non-receptor tyrosine kinase, Jak2. Activation of Jak2 leads to mitogenic proliferation, phosphorylation of intracellular proteins, MAP kinase activation, activation of Stats 1, 3, and 5, and induction of target gene expression. Specific cytoplasmic domains of the growth hormone receptor mediate Jak2 activation, metabolic actions of growth hormone, Stat activation, and calcium influx.

Usefulness of diagnostic tests for biliary obstruction

We studied the value of tests commonly used in diagnosing obstructive jaundice in 188 patients operated on for biliary obstruction. Ultrasonography had a diagnostic accuracy of 87 percent for gallbladder stones, 82 percent for dilated ducts, and 80 percent for pancreatic masses. Computed tomography was 93 percent accurate in diagnosing dilated ducts, and 93 percent accurate in diagnosing a pancreatic mass. Intravenous cholangiography gave useful information in only 4 of 21 patients. Among 45 patients, endoscopic retrograde cholangiopancreatography was technically successful in 91 percent and gave accurate diagnostic information in 86 percent and partially diagnostic information in 7 percent; it detected all cases of common duct stones and had a 91 percent sensitivity for detecting pancreatic cancer. Among 75 patients, transhepatic cholangiography was technically successful in 95 percent and provided accurate diagnostic information in 90 percent and partially diagnostic information in 3 percent; it detected all cases of common duct stones and 95 percent of cases of benign strictures. With persistent jaundice, ultrasonography should be the first test because it is less costly than computed tomography and provides similar information. If more information is needed, transhepatic cholangiography and endoscopic retrograde cholangiopancreatography are equally accurate; transhepatic cholangiography more often opacifies the proximal biliary tree and endoscopic retrograde cholangiopancreatography provides direct access to the ampulla of Vater and the pancreatic duct.

Corticosteroid metabolism in human granulosa-lutein cells

OBJECTIVE

The aims of this study were to determine the type and level of 11 beta-hydroxysteroid dehydrogenase (11 beta HSD) in human granulosa-leutein cells (GLE) shortly before ovulation and to correlate activity with the outcome of treatment in patients undergoing in vitro fertilization and embryo transfer (IVF/ET).

DESIGN

GLC from 32 patients undergoing IVF/ET were tested for type and level of 11 beta HSD activity in relation to treatment outcome.

PATIENTS

Periovulatory follicles were aspirated by ultrasound guided transvaginal puncture following a standard controlled ovarian stimulation protocol, approximately 36 h after administering an ovulation-inducing dose of human chorionic gonadotrophin (HCG). GLC were separated from follicular fluid by density-gradient centrifugation and taken for measurement of 11 beta HSD activity in vitro; oocytes were used for IVF/ET.

MEASUREMENTS

Interconversion of cortisol (F) and cortisone (E), and dexamethasone (D) and 11-dehydrodexamethasone (DHD) was measured in standardized assays comprising incubation of GLC with 3H-labelled substrate, with separation of substrate and product by thin-layer radiochromatography.

RESULTS

Conversion of F to E varied from 10.5 to 30.9% while that of E to F was between 2.4 and 44.6%. In the GLC of 25 patients in whom both activities were measured, dehydrogenase (F to E) activity predominated in 13 and reductase (E to F) in 12. By contrast, D (substrate for 11 beta HSD2 but not 11 beta HSD1) showed less than 1% metabolism in this system while DHD (substrate for 11 beta HSD1 and 11 beta HSD2) was converted significantly (65.6-90.5%) to D in the four patients tested. There was no significant difference in the interconversion of F and E between patients who became pregnant and those who did not.

CONCLUSIONS

The dehydrogenase and oxoreductase reactions catalysed by 11 beta HSD both occur in granulosa-lutein cells at the time of follicular rupture, probably due to 11 beta HSD1. A lack of measurable conversion of dexamethasone to 11-dehydrodexamethasone suggests that dehydrogenation due to 11 beta HSD2 is low or absent. Neither type nor level of 11 beta HSD activity measured under the present assay conditions correlates with IVF outcome.

Ontogenic maturation of the somatotropin/insulin-like growth factor axis

The ontogeny of the somatotropin/insulin-like growth factor system was examined in well-fed pigs under basal conditions and during a short-term challenge of porcine ST (pST). The study was conducted with two replicates of eight castrate male pigs from 3.8 kg BW (10 d of age) to 92 kg BW (129 d of age). Pigs were reared individually with ad libitum access to milk replacer through 23 d of age. Thereafter, pigs were fed a corn, soybean meal, and dry skim milk diet formulated to exceed nutrient requirements by approximately 30%. Pigs were randomly assigned to receive daily i.m. injections of either 0 (buffer) or 120 microg/kg BW of pST for a duration of 4 d starting at 10, 19, 33, 43, 63, 83, and 125 d of age. Blood was collected via jugular venipuncture on d 0 and 4 of the challenge. Circulating levels of IGF-I were not dramatically affected by age, but levels of IGF-II were low from 10 to 19 d of age and then increased through later stages of growth. Circulating concentrations of IGF binding protein (BP)-3 increased with age (P < .05), but levels of IGFBP-2, a 30-kDa IGFBP, and IGFBP-4 were unchanged (P > .10). The pST challenge reduced plasma urea nitrogen at all ages, but the magnitude of the response was less in younger pigs compared with the maximum response in pigs greater than 30 kg BW (63 d of age). The IGF-I response to the pST challenge also increased from approximately 30% in young pigs to a threefold increase in older pigs. Regardless of age, concentrations of IGF-II were minimally affected by the pST challenge. Circulating levels of IGFBP-3 increased and IGFBP-2 levels decreased in response to the pST challenge, and the magnitude increased with age. The high nutritional status of pigs in the early phases of growth diminished the postnatal changes in IGF-I and IGFBP-2, but not IGF-II or IGFBP-3. Overall, data demonstrate a developmental regulation of the ST/IGF system, with pST challenges altering circulating concentrations of IGF-I, IGFBP-3, and IGFBP-2 coincident with changes in amino acid metabolism.

A prospective, pilot study of early corticosteroid cessation in high-immunologic-risk patients: the Cincinnati experience

BACKGROUND

The first prospective trial of steroid withdrawal dedicated to high-immunologic-risk patients is reported herein.

METHODS

Twenty-five patients were enrolled prospectively in an IRB-approved HIPAA-compliant protocol. Immunosuppression included corticosteroid withdrawal (CSWD) at 7 days, tacrolimus (target trough level 4 to 8 ng/mL), sirolimus (target trough level 8 to 12 ng/mL), and Mycophenolate Mofetil (2 g/d). Induction with daclizumab (2 mg/kg) on posttransplant days (PTD) 0 and 14 was administered to the first 10 patients. The protocol for the next 15 patients was modified because of high acute rejection rates to include received T-cell-depleting antibody induction therapy with thymoglobulin (1.5 mg/kg) on PTDs 0 and 2 followed by daclizumab on Postoperative day (POD) 14. Recipient inclusion criteria included: (1) repeat transplant recipients; or (2) patients with a peak PRA > or =25%. All rejection episodes were diagnosed by biopsy and graded using Banff '97 criteria.

RESULTS

Twenty-five patients were enrolled and median follow-up was 402 days. Forty percent of recipients were black, 68% of patients were repeat transplant recipients, 68% received deceased donor kidneys, and 36% had a peak flow PRA >25%. Overall acute rejection, graft survival, and patient survival rates of 40%, 88%, and 96%, respectively, were observed for the duration of the study. Acute rejection occurred in 6 of 10 patients (60%) with daclizumab induction; however, acute rejection rates fell to 27% when thymoglobulin was introduced (P = .1).

CONCLUSIONS

This study supports our previous observations in a multivariate analysis of early CSWD patients, wherein polyclonal antibody induction therapy reduced acute rejection. High-immunologic-risk patients may be able to undergo early CSWD with acceptable rates of acute rejection.

Bilirubin and alkaline phosphatase values before and after surgery for biliary obstruction

From a study of 178 patients who underwent operation for biliary obstruction, we found that preoperative bilirubin values above 14 mg/dl and alkaline phosphatase values over 5 times normal meant that common duct stones were an unlikely cause of the obstruction. Jaundice for more than 4 weeks before operation, bilirubin values greater than 10 mg/dl and the presence of significant fibrosis in the portal spaces indicated a lower than average chance of postoperative resolution of jaundice. After successful biliary surgery, the rate of decrease in serum alkaline phosphatase was haphazard and of little diagnostic value. The postoperative rate of decrease in the bilirubin values followed first-order kinetics and averaged 8 percent/day. This rate was not significantly influenced by the disease process, the length of preoperative clinical jaundice or the absolute height of the preoperative serum bilirubin level.

Physiological aspects of low-density lipoprotein oxidation

The oxidation of LDL is thought to be a major contributor to the development of atherosclerosis. Considerable descriptive evidence has been accumulated showing that oxidized LDL promotes pro-atherogenic events. However, direct evidence that oxidized LDL causes atherosclerosis is lacking. This article summarizes the results of recent studies that demonstrate how oxidized LDL affects cellular function, and highlights key issues that should be addressed to link LDL oxidation with atherosclerosis.

Laparoscopic right living donor nephrectomy

INTRODUCTION

Left laparoscopic donor nephrectomy (LDN) is preferred over right LDN due to technical ease. The purpose of this study was to compare results between right and left LDN and thereby determine whether substantial experience with right LDN can provide results equivalent to left LDN.

METHODS

All LDN from 2000 to 2004 were reviewed, and right LDN data compared to left LDN data. Statistical analyses included chi-square and Student t tests.

RESULTS

Two hundred thirteen left LDN (84%) were compared to 40 right LDN (16%). Donor age, gender, race, and body mass index, and multiple arteries were similar in right and left LDN groups. Operative and cold ischemia times were similar, but warm ischemia was longer for right LDN (3:55 +/- 1:22 minutes) than left LDN (3.18 +/- 1:06 minutes; P = .004). Despite this, renal allograft function was similar on postoperative day 7 (creatinine 1.77 +/- 1.21 for right LDN, 1.7 +/- 1.5 for left LDN) and at 1 year (right LDN 1.5 +/- 0.4, left LDN 1.23 +/- 0.28). Graft survival rate in the right LDN at 1 year was 97.5%.

CONCLUSIONS

This large experience with right LDN indicates that results comparable to left LDN can be obtained. This observation increases the options for LDN in patients with multiple left renal arteries, or with right renal cysts, or with right kidneys that are smaller in size compared to the contralateral left kidney.

Rapid activation of rat insulin-like growth factor-I gene transcription by growth hormone reveals no alterations in deoxyribonucleic acid-protein interactions within the major promoter

Insulin-like growth factor-I (IGF-I) is an important mediator of prenatal and postnatal growth, but little is known about the control of IGF-I gene expression. Previously, we demonstrated that GH rapidly stimulates hepatic IGF-I transcription in vivo in hypophysectomized (hypox) rats. In this study, we show that GH induces IGF-I gene transcription through the major promoter, promoter 1, and identify and characterize DNA-protein interactions throughout the promoter. In vitro deoxyribonuclease-I footprinting was used to analyze 1711 nucleotides of promoter 1 and the entire 328-nucleotide 5'-untranslated region of exon 1, using hepatic nuclear protein extracts from male juvenile hypox rats given a single ip injection of GH or saline 60 min before death. Fourteen DNA-protein binding sites were identified, with 6 located in the highly conserved 5'-untranslated region of exon 1. These latter sites were further characterized for specificity and regulation by GH, using gel mobility shift assays. Two of these DNA-protein interactions were also detected by in vivo dimethylsulfate footprinting. All DNA-protein binding was seen using hepatic nuclear protein extracts from hypox rats and did not change within 15, 30, 60, or 120 min after treatment with GH. Our results thus define a series of constitutive DNA-protein interactions within the major rat IGF-I gene promoter that may be involved in mediating GH-activated nuclear signals to initiate IGF-I transcription.

Randomized controlled trial investigating the effect of 2 selective dry-cow therapy protocols on udder health and performance in the subsequent lactation

The objective of this study was to compare culture- and algorithm-guided selective dry-cow therapy (SDCT) programs with blanket dry-cow therapy (BDCT) in a multi-site, randomized, natural exposure clinical trial for the following cow-level outcomes: clinical mastitis, removal from the herd, and Dairy Herd Improvement Association (DHIA) test-day milk yield and SCC measures during the first 120 d in milk (DIM). Two days before planned dry-off, cows in each of 7 herds were randomly allocated to BDCT, culture-guided SDCT (cult-SDCT), or algorithm-guided SDCT (alg-SDCT). At dry-off, BDCT cows received an intramammary antibiotic (500 mg of ceftiofur hydrochloride) in all 4 quarters. Antibiotic treatments were selectively allocated to quarters of cult-SDCT cows by only treating quarters from which aseptically collected milk samples tested positive on a rapid culture system after 30 to 40 h of incubation. For alg-SDCT cows, antibiotic treatments were selectively allocated at the cow level, with all quarters receiving antibiotic treatment if the cow met at least one of the following criteria: (1) any DHIA test with a somatic cell count >200,000 cells/mL during the current lactation, and (2) ≥2 clinical mastitis cases during the current lactation. All quarters of all cows were treated with an internal teat sealant. Clinical mastitis and removal from the herd events (i.e., culling or death) and DHIA test-day data from dry-off to 120 DIM were extracted from herd records. Hazard ratios (HR) for the effect of treatment group on clinical mastitis and removal from the herd during 1 to 120 DIM were determined using Cox proportional hazards regression. The effects of treatment group on test-day log_e-transformed SCC and milk yield were determined using linear mixed models. Final models indicated that either SDCT program was unlikely to increase clinical mastitis risk (HR_{cult-SDCT/BDCT} = 0.82, 95% CI: 0.58, 1.15; HR_{alg-SDCT/BDCT} = 0.83, 95% CI: 0.63, 1.09) or test-day log_eSCC (cult-SDCT minus BDCT = 0.05, 95% CI: -0.09, 0.18; alg-SDCT minus BDCT = 0.07, 95% CI: -0.07, 0.21). Risk of removal from the herd and test-day milk yield were similar between treatment groups. Findings from this study indicate that culture- or algorithm-guided SDCT can be used at dry-off without negatively affecting cow health and performance in early lactation.

Detecting and identifying volatile aldehydes as dinitrophenylhydrazones using gas chromatography mass spectrometry

The detection of aldehydes has become an important measure of lipid oxidation in biological milieu. Aldehyde 2,4-dinitrophenylhydrazones are easily prepared and readily purified by HPLC and/or TLC and have proven useful for the detection of aldehydes. The lower limit of detection for dinitrophenylhydrazones was significantly reduced by using gas chromatography-mass spectrometric (GC-MS) techniques. Individual dinitrophenylhydrazones were readily separated by GC and detected by both positive and negative ion MS. The two major ions in negative ion spectra were the 182 m/z fragment ion and the molecular ion. Positive ion spectra showed strong ions corresponding to the protonated molecular ion and a protonated iminium ion. The greatest sensitivity was obtained with negative ion detection (10 pg per injection). However, more structural information was obtained from analysis of the positive ion spectra. Dinitrophenylhydrazones of hydroxyaldehydes, like 4-hydroxynonenal, were analyzed after converting the dinitrophenylhydrazones into trimethylsiloxylethers. GC-MS with negative ion detection was used to identify and quantitate the release of 4-hydroxynonenal by alveolar macrophages exposed to nitrogen dioxide.

Synthesis and characterization of a new photocrosslinking CTP analog and its use in photoaffinity labeling E. coli and T7 RNA polymerases

A new photocrosslinking CTP analog that functioned as a substrate during transcription was synthesized and used to photoaffinity label E. coli and bacteriophage T7 RNA polymerases. This analog, 5-((4-azidophenacyl)thio) cytidine-5'-triphosphate (5-APAS-CTP) contains an aryl azide group approximately 10 A from the nucleotide base and specifically replaced CTP during synthesis of RNA by both polymerases. Analog was placed at the 3' end or internally within RNA. Both polymerases inefficiently incorporated two 5-APAS-CMP molecules sequentially, as was found for the related 5-APAS-UMP. Analog was placed at the 3' end of RNA in transcription complexes paused at the site of Q-modification of E. coli RNA polymerase, downstream of the lambda PR' promoter (+16), a pause that requires specific DNA sequences but no apparent RNA hairpin. Crosslinking was examined in the presence and absence of the NusA protein, which enhances the transcriptional pause at this site and is required for Q modification of the polymerase. Crosslinking of the 3' end of the RNA to NusA was not observed, consistent with our earlier results involving a NusA-enhanced pause site downstream from an RNA hairpin.

Effect of 15-lipoxygenase-derived arachidonate metabolites on human neutrophil degranulation

Products of the 15-lipoxygenase pathway of arachidonate metabolism, prepared by techniques that effectively free them from contaminants, were examined for their ability to influence human neutrophil degranulation. 15(S)-Hydroxyicosatetraenoate [15(S)-HETE], 8(S),15(S)-dihydroxyicosatetraenoate, and 5(S),15(S)-dihydroxyicosatetraenoate did not directly stimulate this response, but 5(S),15(S)-dihydroxyicosatetraenoate (158-5000 nM) enhanced degranulation responses elicited by platelet-activating factor and its structural analogues. It had no such effect on the degranulation responses elicited by a tripeptide chemotactic factor, phorbol myristate acetate, leukotriene B4, or ionophore A23187. In many of these respects, the potentiating actions of 5,15-dihydroxyicosatetraenoate paralleled the actions of 5(S)-hydroxyicosatetraenoate. Indeed, these two metabolites had potentiating actions on platelet-activating factor that were non-additive and, under specific conditions, cross-desensitized each other. Based on the structural specificity demonstrated by these and other mono- and dihydroxyeicosatetraenoates in potentiating platelet-activating factor as well as their mutual cross-desensitizing actions, we suggest that 5-hydroxylated arachidonate metabolites act by a structurally specific receptor to potentiate human neutrophil responses to certain stimuli.

Acetaldehyde (CH3CHO) production in rodent lung after exposure to metal-rich particles

Epidemiological reports demonstrate an association between increased human morbidity and mortality with exposure to air pollution particulate matter (PM). Metal-catalyzed oxidative stress has been postulated to contribute to lung injury in response to PM exposure. We studied the effects of residual oil fly ash (ROFA), a component of ambient air PM, on the formation of lung carbonyls that are indicators of lipid peroxidation. Rats were instilled intratracheally with ROFA (62.5-1000 micrograms) and underwent lung lavage. Lavage fluid carbonyls were derivatized with 2,4-dinitrophenylhydrazine, and measured by high performance liquid chromatography with UV detection. Dose-dependent increases in a peak that eluted with the same retention time as the acetaldehyde (CH3CHO) derivative was observed in rats treated with ROFA 15 min after instillation (up to 25-fold greater than saline treated controls). The identification of CH3CHO was confirmed using gas chromatography-mass spectroscopy. ROFA-induced increases in other lavage fluid carbonyls were not seen. Increased CH3CHO in lavage fluid was observed as late as 8 h later. No increase in CH3CHO was observed in plasma from ROFA-treated rats. An increased formation of CH3CHO was observed in a human airway epithelial cell line incubated with ROFA suggesting a pulmonary source of CH3CHO production. Instillation of solutions of metals (iron, vanadium, nickel) contained in ROFA, or instillation of another ROFA-type particle containing primarily iron, also induced a specific increase in CH3CHO. These data support the hypothesis that metals were involved in the increased CH3CHO formation. Thus metals on PM may mediate lung responses through induction of lipid peroxidation and carbonyl formation.

Vasectomy: a long-term study of its effects on testicular endocrine function in man

Plasma testosterone, luteinizing hormone (L.H.) and follicle stimulating (F.S.H.) were measured before operation in 39 males, aged 26 to 53 years with 2 to 5 children, seeking vasectomy for contraceptive purposes. These measurements were repeated at 3 and 12 months after vasectomy. Levels of L.H. at 12 months were significantly higher than pre-vasectomy levels, suggesting some degree of decreased Leydig cell function. However, testosterone and F.S.H. levels were similar at the three sampling times. Continuing yearly measurements for at least 5 years are planned.

Midfoot osteoarthritis: potential phenotypes and their associations with demographic, symptomatic and clinical characteristics

OBJECTIVE

To investigate the demographic, symptomatic, clinical and structural foot characteristics associated with potential phenotypes of midfoot osteoarthritis (OA).

DESIGN

Cross-sectional study of 533 community-dwelling adults aged ≥50 years with foot pain in the past year. Health questionnaires and clinical assessments of symptoms, foot structure and function were undertaken. Potential midfoot OA phenotypes were defined by the pattern of radiographic joint involvement affecting either the medial midfoot (talonavicular, navicular-1^st cuneiform, or cuneiform-1^st metatarsal joint), central midfoot (2^nd cuneiform-metatarsal joint), or both medial and central midfoot joints. Multivariable regression models with generalised estimating equations were used to investigate the associations between patterns of midfoot joint involvement and symptomatic, clinical and structural characteristics compared to those with no or minimal midfoot OA.

RESULTS

Of 879 eligible feet, 168 had medial midfoot OA, 103 central midfoot OA, 76 both medial and central midfoot OA and 532 no/minimal OA. Having both medial and central midfoot OA was associated with higher pain scores, dorsally-located midfoot pain (OR 2.54, 95%CI 1.45, 4.45), hallux valgus (OR 1.76, 95%CI 1.02, 3.05), flatter foot posture (β 0.44, 95%CI 0.12, 0.77), lower medial arch height (β 0.02, 95%CI 0.01, 0.03) and less subtalar inversion and 1^st MTPJ dorsiflexion. Isolated medial midfoot OA and central midfoot OA had few distinguishing clinical characteristics.

CONCLUSIONS

Distinct phenotypes of midfoot OA appear challenging to identify, with substantial overlap in symptoms and clinical characteristics. Phenotypic differences in symptoms, foot posture and function were apparent in this study only when both the medial and central midfoot were involved.

Neutropenia induced by systemic infusion of 5,12-dihydroxy-6,8,10,14-eicosatetraenoic acid: correlation with its in vitro effects upon neutrophils

5(S), 12(S)-Dihydroxy-cis-14,trans-6,8,10-eicosatetraenoate (compound I), 5(S),12(R)-dihydroxy-cis-14,trans-6,8,10-eicosatetraenoate (compound II), and 5(S),12(R)-dihydroxy-cis-6,14,trans-8,10-eicosatetraenoate (compound III) were prepared from rabbit peritoneal neutrophils challenged with arachidonic acid plus ionophore A23187. Each arachidonate metabolite caused rabbit neutrophils to aggregate and, in cells treated with cytochalasin B, release granule-bound enzymes. Compound III was 10- to 100-fold more potent than compounds II and I. When intravenously infused into rabbits at doses of 100--1,000 ng/kg, compound III induced abrupt, profound, transient neutropenia associated with a rapidly reversing accumulation of neutrophils in the pulmonary circulation. This in vivo action correlated closely with the ability of the fatty acid to activate neutrophils in vitro: neutropenia, aggregation, and degranulation occurred at similar doses of stimulus and the rapid, reversing kinetics of the neutropenic response paralleled the equally rapid, reversing formation of aggregates. The fatty acid did not alter the circulating levels of lymphocytes or platelets and did not aggregate platelets in vitro. At comparable doses (i.e., 100--1,000 ng/kg), compounds I and II did not cause neutropenia. Thus, compound III possesses a high degree of structural and target-cell specificity in stimulating neutrophils in vitro and in vivo. Clinical and experimental syndromes associating neutropenia with increased levels of circulating arachidonate metabolites may involve compound III as a mediator of neutrophil sequestration in lung.

Laparoscopic Living Donor Nephrectomy for Kidneys With Multiple Arteries

INTRODUCTION

Laparoscopic donor nephrectomy (LDN) involving kidneys with multiple arterial vessels is limited to a small number of reports, with all but two series reporting fewer than 25 patients. Moreover, outside of the pioneering centers at the University of Maryland and Johns Hopkins, no series of at least 25 patients has been published confirming these experience. The present study presents the largest series of LDN of donor kidneys with multiple arterial vessels outside of these two pioneering programs.

METHODS

All LDN performed at the University of Cincinnati from 2000 to 2004 were reviewed. Results between LDN kidneys with a single vessel and those with multiple vessels were compared. Statistical analysis included chi-square and Student t test.

RESULTS

Of 240 LDN, 37 were performed for kidneys with multiple vessels (15%): nine right kidneys (25%) and 28 left kidneys (75%). Cold ischemia time was longer for the multiple vessel organs (46 +/- 24 minutes) than for single vessel organs (35 +/- 13 minutes; P = .001), and warm ischemia time was longer for the multiple vessel kidneys (4:20 +/- 2:05 minutes) than single vessel kidneys (3:13 +/- 0:47 minutes; P = .001). Recipient renal function (serum creatinine) was similar for multiple and single artery donors at postoperative day 7 (1.76 +/- 1.38 and 1.7 +/- 1.47) and at postoperative day 365 (1.06 +/- 0.3 and 1.34 +/- 0.44).

CONCLUSIONS

This experience confirms results from other series in documenting the safety and reproducibility of LDN for kidneys with multiple arterial vessels.

Use of diethylenetriamine penta-acetic acid (D.T.P.A.) in the clinical assessment of total body iron stores

As a quantitative test of iron storage the six-hour urinary excretion of iron was measured after the intravenous infusion of the iron-chelating agent diethylenetriamine penta-acetic acid (D.T.P.A.). The value of this test in determining the presence and magnitude of the total body iron stores was assessed in patients with diseases of iron storage. In patients with idiopathic haemochromatosis and in their first-degree relatives with increased iron stores as measured by hepatic biopsy, the result of the D.T.P.A. test fell progressively as iron stores were reduced by venesection therapy. There was a significant correlation between the result of the D.T.P.A. test and the excess iron storage as measured retrospectively by the effects of venesection therapy, and also between the D.T.P.A. test and the unsaturated iron-binding capacity (U.I.B.C.) in these patients. In patients with excess iron stores due to diseases other than idiopathic haemochromatosis (e.g., alcoholic cirrhosis, haemochromatosis associated with refractory anaemia) the D.T.P.A. test demonstrated the presence of excess iron stores, but the results were very variable and did not correlate closely with the U.I.B.C. or the degree of hepatic haemosiderin deposits. Unexpectedly high results for the D.T.P.A. test were found in some patients with iron-deficiency anaemia.

MEHP/DEHP: gonadal toxicity and effects on rodent accessory sex organs

The phthalate acid esters (PAEs), and, in particular, di(2-ethylhexyl) phthalate (DEHP) and its monoester, monoethylhexyl phthalate (MEHP), can adversely affect rodent testes but only at high doses. Rat gonadal zinc levels can be decreased by the injection of DEHP, but not MEHP. The rat prostate gland seems to be particularly sensitive to PAE-induced zinc depletion. PAE-induced changes in male reproductive organs were more evident in the rat than in the mouse. Some of the effects of MEHP can be demonstrated in vitro since it can alter the uptake of 65Zn in rodent gonads and accessory sex organs.

The place of electron spin resonance methods in the detection of oxidative stress in type 2 diabetes with poor glycemic control

OBJECTIVE

Chronic production of reactive oxygen species (ROS) and/or deficiency in the antioxidant defense system are observed in non-insulin-dependent diabetes mellitus (NIDDM) patients. As an adjunct to the usual indirect parameters for evaluating oxidative stress, we assessed the feasibility of oxyradicals detection in venous blood by electron spin resonance spectroscopy (ESR). Detection of the ascorbate pool was also performed using the validated ESR analysis of the ascorbyl free radial (AFR)-dimethyl sulfoxide (DMSO) complex.

METHODS AND RESULTS

Plasma lipoperoxidation was characterized by higher levels of total MDA (1.50 +/- 0.08 nmol/L), lower levels of GSH (0.54 +/- 0.02 mmol/L) and of vitamin A (2.13 +/- 0.52 mumol/L) in the NIDDM group than in the controls (0.75 +/- 0.05 nmol/L, 0.90 +/- 0.05 mmol/L, 3.52 +/- 1.04 mumol/L, respectively). Improvement of the ESR measurement of oxyradical adducts has been previously obtained by addition of a new sensitive nitrone (DEPMPO), which acts as a spin-trap. However, in our experiment the ESR signal-to-noise ratio was too low to detect significative oxyradicals adducts in total venous blood of NIDDM patients having a weak production of ROS. A significant difference (p < 0.002) was observed in DMSO/AFR index between controls (24.00 +/- 4.10 nmol/L) and NIDDM patients (7.28 +/- 2.36 nmol/L) suggesting ascorbate depletion related to the free radical production.

CONCLUSION

The DMSO/AFR index could be an interesting additional marker of oxidative stress during a chronic production of ROS.

Dietary fatty acids, low density lipoprotein composition and oxidation and primate atherosclerosis

Low density lipoproteins (LDL) were isolated from nonhuman primates fed isocaloric diets rich in different types of fatty acids. These diets contained 35% of calories as fat enriched in fatty acids from the following sources: lard that is rich in saturated fatty acids, safflower oil rich in oleic acid, safflower oil rich in linoleic acid and menhaden oil that is rich in n-3 fatty acids. LDL composition reflected the dietary fats. LDL were subjected to oxidation using copper ions and azobis(2-amidinopropane) x 2HCl. In general, the sensitivity of LDL to oxidation depended on both the poly-unsaturated fatty acid and vitamin E content. However, the lag times calculated for the copper ion catalyzed oxidations did not show the linear dependence on vitamin E content that was found for azobis(2-amidinopropane) catalyzed oxidation.