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An evaluation of the effects of soil structural heterogeneity on maize (Zea mays L.) root system architecture was carried out on plants grown in boxes containing fine soil and clods. The clods were prepared at two levels of moisture (0.17 and 0.20 g/g) and bulk density (ranges 1.45-1.61 g/ml and 1.63-1.79 g/ml). Soil moisture directly affected the probability of clod penetration by maize roots. Primary roots inside the clods manifested morphological deformations in the form of bends. We observed a significant increase of bends per root length at lower soil moisture (P = 0.02). Root diameter and branching density increased, and lateral root length decreased considerably inside the clods. However, once emerging out of the clods and into free soil, values of all three characteristics remained low. While changes in root diameter were caused mainly by clod moisture (P < 0.05), length of lateral roots was related to bulk density (P < 0.01). Branching density was modified exclusively by an interactive effect of both factors (P < 0.05).

Soil compaction heterogeneity and water content are supposed to be decisive factors influencing plant growth. Our experiment focused on simulation of two soil moisture levels (0.16 and 0.19 g/g) plus two levels of clod proportion (30 and 60% volume) and their effects on root and leaf variables of maize (Zea mays L.). We studied number of primary and lateral roots as well as primary root length at the particular soil depths. Statistical tests showed that the decrease rate of the number of roots versus depth was significantly affected by the two studied factors (P < 0.01). Soil moisture and clod occurrence, interactively, affected leaf biomass (P = 0.02). Presence of clods modified root morphological features. Particularly, the diameter of primary roots in the clods was significantly higher than of those grown in fine soil (P < 0.01). For primary roots, which penetrated clods, branching density decreased considerably for the root segments located just after the clods (P = 0.01). Regarding their avoidance to clods and tortuosity, large differences were found between primary roots grown in the contrasting soil environments.

Purpose: Currently, nearly 90% of patients with congenital heart disease (CHD) reach adulthood in relatively good health. Structured transition programs have emerged to support adolescents and young adults in transitioning to adult care structures, improve their autonomy, and limit healthcare ruptures. The TRANSITION-CHD randomized controlled trial aimed to assess the impact of a transition program on health-related quality of life (HRQoL) in adolescents and young adults with CHD., Methods: From January 2017 to February 2020, 200 subjects with a CHD, aged 13-25 years, were enrolled in a prospective, controlled, multicenter study and randomized in two balanced groups (transition program vs. standard of care). The primary outcome was the change in PedsQL self-reported HRQoL score between baseline and 12-month follow-up, using an intention-to-treat analysis. The secondary outcomes were the change in disease knowledge, physical health (cardiopulmonary fitness, physical activity), and mental health (anxiety, depression)., Results: The change in HRQoL differed significantly between the transition group and the control group (mean difference = 3.03, 95% confidence interval (CI) = [0.08; 5.98]; p = .044; effect size = 0.30), in favor of the intervention group. A significant increase was also observed in the self-reported psychosocial HRQoL (mean difference = 3.33, 95% CI = [0.01; 6.64]; p = .049; effect size = 0.29), in the proxy-reported physical HRQoL (mean difference = 9.18, 95% CI = [1.86; 16.51]; p = .015; effect size = 0.53), and in disease knowledge (mean difference = 3.13, 95% CI = [1.54; 4.72]; p < .001; effect size = 0.64)., Discussion: The TRANSITION-CHD program improved HRQoL and disease knowledge in adolescents and young adults with CHD, supporting the generalization and systematization of similar preventive interventions in pediatric and congenital cardiology., (Copyright © 2024 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.)

Objective: Trigger finger is one of the most common pathologies of the finger flexor mechanism. Previous studies have shown the value of ultrasound-guided percutaneous tenolysis. The aim of this study was to compare the efficacy and safety of anterograde versus retrograde percutaneous ultrasound-guided tenolysis., Materials and Methods: This was a comparative cadaver study performed between December 2021 and April 2022 in France, with 40 fresh cadaver fingers. Thumbs were excluded. A single surgeon performed 20 ultrasound-guided anterograde releases and 20 ultrasound-guided retrograde releases, using a second-generation minimally invasive surgical knife, and a multipurpose linear ultrasound transducer. The primary endpoint was the success of ultrasound-guided release, defined as complete opening of the A1 pulley along its entire length., Results: The success rate was 90% in the retrograde group and 95% in the anterograde group (non-significant difference: p = 0.56). There was no significant difference in superficial flexor tendon slip injuries or partial A2 pulley injuries. There were no neurovascular pedicle lesions., Conclusion: The choice of anterograde or retrograde ultrasound-guided tenolysis should be left to the surgeon's discretion., (Copyright © 2023 SFCM. Published by Elsevier Masson SAS. All rights reserved.)

Objectives: The emergence of biologics has improved the course of inflammatory bowel diseases (IBD) in the elderly population despite a potential higher risk of infections. We conducted a one-year, prospective, multicenter, observational study to determine the frequency of occurrence of at least one infectious event in elderly IBD patients under anti-TNF therapy compared with that in elderly patients under vedolizumab or ustekinumab therapies., Methods: All IBD patients over 65 years exposed to anti-TNF, vedolizumab or ustekinumab therapies were included. The primary endpoint was the prevalence of at least one infection during the whole one year follow-up., Results: Among the 207 consecutive elderly IBD patients prospectively enrolled, 113 were treated with anti-TNF and 94 with vedolizumab (n=63) or ustekinumab (n=31) (median age 71 years, 112 Crohn's disease). The Charlson index was similar between patients under anti-TNF and those under vedolizumab or ustekinumab as well as the proportion of patients under combination therapy and under concomitant steroid therapy did not differ between both both groups. The prevalence of infections was similar in patients under anti-TNF and in those under vedolizumab or ustekinumab (29% versus 28%, respectively; p=0.81). There was no difference in terms of type and severity of infection and of infection-related hospitalization rate. In multivariate regression analysis, only the Charlson comorbidity index (≥ 1) was identified as a significant and independent risk factor of infection (p=0.03)., Conclusion: Around 30 % of elderly patients with IBD under biologics experienced at least one infection during the one-year study follow-up period. The risk of occurrence of infection does not differ between anti-TNF and vedolizumab or ustekinumab therapies, and only the associated comorbidity was linked with the risk of infection., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)

The recurrence of non-metastatic endometrial carcinoma (EC) (6 to 21%) might be due to disseminated tumor cells. This feasibility study investigated whether circulating tumor cells (CTCs) were detectable in blood samples from the peripheral and ovarian veins of 10 patients undergoing laparoscopic resection of stage I-II EC between July 2019 and September 2021. CTCs were detected using the CellSearch ® system (i) preoperatively (T0) in peripheral blood, (ii) after ovary suspensory ligament pediculation in ovarian vein blood (T1), and (iii) before colpotomy in peripheral blood (T2). CTCs were detected only in ovarian vein samples in 8/10 patients. The CTC median number did not differ with patient age (37 (min-max: 0-91) in <70-year-old vs. 11 (0-65) in ≥70 year-old women, p = 0.59), tumor grade (15 (0-72) for grade 1 vs. 15 (0-91) for grade 2, p = 0.97), FIGO stage (72 (27-91) vs. 2 (0-65) vs. 3 (0-6]) for stage IA, B, and II, respectively; p = 0.08), and tumor size (40 (2-72) for size < 30 mm vs. 4 (0-91) for size ≥ 30 mm, p = 0.39). Estrogen receptor-positive CTCs and CTC clusters were identified. The prognostic and therapeutic values of CTCs released during EC surgery need to be determined.

Objectives: The main objective of this study was to determine the rate of outpatient management in a population of patients undergoing bilateral ethmoidectomy. The secondary objectives were to evaluate the quality of outpatient management (rate of unscheduled overnight admission, readmission rate, complications) and to compare inpatient and outpatient groups to determine which elements of the phenotype and care pathway favored outpatient management., Materials and Methods: A single-center observational study included 204 patients operated on for bilateral ethmoidectomy. Study variables comprised: type of care pathway (outpatient/inpatient), outpatient quality indicators (unscheduled admission, readmission, complications), care pathway, and population characteristics., Results: One hundred and twenty (58.8%) outpatients were operated on. No deaths occurred. The unscheduled admission rate was 7.5%, and the readmission rate 4.1%; at the P<0.005 threshold, there were no significant differences between in- and out-patient groups. Outpatients had earlier surgery (P<0.005), and nasal packing rates and pain on VAS were lower (P<0.005)., Conclusion: Ethmoidectomy could be carried out as an outpatient procedure in 58.8% of cases, with acceptable quality of care. Selection of patients and the organization of a dedicated care pathway seem to be elements favoring this management., (Copyright © 2021. Published by Elsevier Masson SAS.)

Background: Increased risk of new-onset atrial fibrillation (AF) after patent foramen ovale (PFO) closure was observed in randomized trials without however systematic AF screening. We aimed to evaluate the incidence of AF within 6-month following PFO closure with serial 24-hour ambulatory electrocardiogram (AECG) monitoring., Methods: All patients undergoing PFO closure were prospectively included in 2 centers. AF was defined as irregular rhythm without discernible P waves > 30 s on AECG at day 0, 1-month and 6-month follow-up. Primary endpoint was the incidence of AF within the study period. Secondary endpoints evaluated clinical outcomes within 6-month follow-up., Results: Between February 2018 and March 2019, 62 patients underwent PFO closure including 40 male (64.5%) with a mean age of 48 ± 9.5. Atrial septal aneurysm was observed in 37 patients (64.9%), 57 patients (91.9%) received an Amplatzer Occluder device (Abbott Vascular) and 5 (8.1%) an Occlutech device (Occlutech). After a mean follow-up of 7.7 ± 2.8 months, new-onset AF occurred in 3 patients (4.8%), all within the first month following PFO closure, including one per-procedural, all were asymptomatic and paroxysmal. Two patients with AF (3.2%) required chronic oral anticoagulant therapy. No adverse outcomes occurred at follow-up. No predictive factors of AF were highlighted. A total of 16 patients (25.8%) reported palpitations without AF on the AECGs., Conclusion: In highly selected patients, incidence of AF, evaluated with 3 systematic 24-hour AECG within 6-month following PFO closure, was low (<5%). Always paroxysmal, AF occurred within the first month after the procedure and was not associated with adverse outcomes., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper: [F. Leclercq received research grants from Edwards, Medtronic, Boehringer; consultant fees from Boehringer; and lecture fees from Astra Zeneca and Bayer. B. Lattuca received research grants from ACTION Study group, Biotronik, Boston Scientific, Daiichi-Sankyo, Fédération Française de Cardiologie and Institute of CardioMetabolism and Nutrition; consultant fees from Daiichi-Sankyo and Eli Lilly; and lecture fees from AstraZeneca and Novartis. G Cayla received research grants/consultant fees/lectures fees from Amgen, AstraZeneca, Bayer, Boehringer-Ingelheim, Boston, Biotronik, Bristol-Myers Squibb, Daiichi-Sankyo, Eli-Lilly, Europa, Fédération Française de Cardiologie, Fondation Cœur & Recherche, Medtronic, MSD, Pfizer, Sanofi-Aventis. M. Akodad received research grants from Fédération Française de Cardiologie, MUSE-Explore, Biotronik and Medtronic.]., (© 2021 The Author(s).)

Purpose: The purpose was to evaluate the clinical and radiological results of knotless repair with flat-braided suture in full small-sized supraspinatus tendon tears (< 1 cm)., Methods: A consecutive series of 54 patients with isolated small supraspinatus tendon tear (< 1 cm and Goutallier index < 2) was evaluated in the study. Patients underwent a knotless arthroscopic repair using flat-braided suture (2 mm wide). Minimal follow-up required was 5 years. Changes in Murley-Constant score, ASES score, strength, and pain relief were assessed. The Sugaya score was used to confirm the tendon repair on MRI. Data were analyzed in two subgroups: technique with additional U point for dog ear deformity (group 1) and technique without additional U point (group 2). The immobilization period was 3 weeks long. Passive mobilization was immediate., Results: Fifty-four patients were included. Mean age was 57 ± 4 years. The average follow-up was 68 ± 10 months. Average preoperative score of Constant was 51.2 ± 8.5 and 83.1 ± 14.6 at the end of the follow-up (p < 0.001). Mean VAS went from 5.8 ± 1.8 to 1.9 ± 2.1 (p < 0.001). Average forward elevation of the shoulder went from 86.3° ± 9 preoperatively to 169.6° ± 15.9 at the end of the follow-up (p < 0.001). The strength score was significantly higher post-operatively (18.4 vs. 8.3, p < 0.001.). The ASES score was significantly improved 49.1 ± 13.1 vs. 88.6 ± 15.8, p < 0.001). The MRI assessment revealed 94% of Sugaya 1-2. No significant difference was observed between group 1 and 2 regarding all clinical outcomes. Two complex regional pain syndromes were described with a favorable evolution. Three patients presented a retear requiring an iterative arthroscopic repair., Conclusion: The use of a knotless arthroscopic construct with flat-braided suture for small supraspinatus repair achieved excellent structural and clinical results. This technique is fully adequate for the arthroscopic treatment of such tears, enabling early mobilization., Level of Evidence: Level III.

Time to reporting antimicrobial susceptibility testing (AST) results to physicians plays an essential role in antibiotic stewardship programs. Expert software has been developed for facilitating the microbiologists' AST review process. The reliability of the VITEK®2 Advanced Expert™ software to effectively alert the microbiologist in detection of atypical and inconsistent AST results was assessed at the Labor Berlin-Charité Vivantes services. The results demonstrated a confidence rate of 99.3% in reporting fully consistent AST results to physicians.

Background: Recent advances in the field of congenital heart disease (CHD) led to an improved prognosis of the patients and in consequence the growth of a new population: the grown up with congenital heart disease. Until recently, more than 50% of these patients were lost to follow up because of the lack of specialized structures. The critical moment is the transition between paediatric and adult unit. Therapeutic education is crucial to solve this issue by helping patients to become independent and responsible. The TRANSITION-CHD randomized trial aims to assess the impact of a transition education program on health-related quality of life (HRQoL) of adolescents and young adults with CHD., Methods: Multicentre, randomised, controlled, parallel arm study in CHD patients aged from 13 to 25 years old. Patients will be randomised into 2 groups (education program vs. no intervention). The primary outcome is the change in self-reported HRQoL between baseline and 12-month follow-up. A total of 100 patients in each group is required to observe a significant increase of the overall HRQoL score of 7 ± 13.5 points (on 100) with a power of 80% and an alpha risk of 5%. The secondary outcomes are: clinical outcomes, cardiopulmonary exercise test parameters (peak VO2, VAT, VE/VCO2 slope), level of knowledge of the disease using the Leuven knowledge questionnaire for CHD, physical and psychological status., Discussion: As the current research is opening on patient related outcomes, and as the level of proof in therapeutic education is still low, we sought to assess the efficacy of a therapeutic education program on HRQoL of CHD patients with a randomized trial., Trial Registration: This study was approved by the National Ethics Committee (South-Mediterranean IV 2016-A01681-50) and was registered on Clinicaltrials.gov (NCT03005626).

Introduction: In traumatic proximal brachial plexus lesions (i.e., C5/C6), reconstruction of the musculocutaneous, axillary and suprascapular nerves yields satisfactory short- and medium-term functional outcomes., Hypothesis: Early functional outcomes after nerve surgery will be maintained in the long-term., Methods: A retrospective analysis was done using the medical records of 29 patients with C5/C6 palsy treated by nerve surgery. Active range of motion and strength at the elbow (i.e., flexion) and shoulder (i.e., flexion, abduction, external rotation with the elbow at the side of the body and with the arm 90° abducted ) were evaluated clinically using a goniometre and the British Medical Research Council grading scale, respectively., Results: At a mean follow-up of 46±15 months (25;76), the mean active elbow flexion was 126°±18° (90;150) and the mean strength was 3.8±0.5 (2;4). At the shoulder, mean active flexion, abduction, external rotation with the elbow at the side of the body and with the arm 90° abducted were 109°±39° (0;180), 99°±38° (0;180°), 12°±34° (-80;70) and 3°±21° (-40;50), while mean strength was 3.6±0.8 (0;4), 3.6±0.8 (0;4), 3.4±0.9 (0;4) and 2.5±1.2 (0;4), respectively., Discussion: In cases of C5/C6 palsy, early nerve surgery yields satisfactory functional outcomes that are maintained over time for elbow flexion and shoulder elevation. However, when the teres minor is not reinnervated, it is difficult to restore satisfactory shoulder external rotation., Level of Evidence: IV, Retrospective case study., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Purpose: To report a farmer's corneal abscess caused by an unusual pathogen: Listeria monocytogenes fluoroquinolone resistant., Methods: A 78-year-old farmer presented a central corneal abscess associated with 1-mm hypopyon and decreased visual acuity evolving since 2 weeks. First an antibiotic therapy associating oral ofloxacin and topical ciprofloxacin, vancomycin and ceftazidime was started. Different samples of the abscess were performed and sent to different microbiological laboratories., Result: Listeria monocytogenes was isolated after 2 days of culture. Antibiotics sensitivity showed resistance to ciprofloxacin, fosfomycin and fusidic acid. Ceftazidime was changed for gentamicin, and after 1 month of treatment the abscess decreased considerably., Conclusion: This case demonstrated that even if Listeria is rarely involved in ocular abscess, it must be evocated for people with risk factors as farmers. This suspicion should lead to an extended incubation to identify the pathogen. The analysis of Listeria resistance is essential to start an efficient therapy.

Cystic fibrosis (CF) lungs harbor a complex community of interacting microbes, including pathogens like Pseudomonas aeruginosa. Meta-taxogenomic analysis based on V5-V6 rrs PCR products of 52 P. aeruginosa-positive (Pp) and 52 P. aeruginosa-negative (Pn) pooled DNA extracts from CF sputa suggested positive associations between P. aeruginosa and Stenotrophomonas and Prevotella, but negative ones with Haemophilus, Neisseria and Burkholderia. Internal Transcribed Spacer analyses (RISA) from individual DNA extracts identified three significant genetic structures within the CF cohorts, and indicated an impact of P. aeruginosa. RISA clusters Ip and IIIp contained CF sputa with a P. aeruginosa prevalence above 93%, and of 24.2% in cluster IIp. Clusters Ip and IIIp showed lower RISA genetic diversity and richness than IIp. Highly similar cluster IIp RISA profiles were obtained from two patients harboring isolates of a same P. aeruginosa clone, suggesting convergent evolution in the structure of their microbiota. CF patients of cluster IIp had received significantly less antibiotics than patients of clusters Ip and IIIp but harbored the most resistant P. aeruginosa strains. Patients of cluster IIIp were older than those of Ip. The effects of P. aeruginosa on the RISA structures could not be fully dissociated from the above two confounding factors but several trends in these datasets support the conclusion of a strong incidence of P. aeruginosa on the genetic structure of CF lung microbiota.

To understand soil colonization by a root system, information is needed on the architecture of the root system. In monocotyledons, soil exploration is mainly due to the growth of adventitious primary roots. Primary root emergence in banana was quantified in relation to shoot and corm development. Root emergence kinetics were closely related to the development of aerial organs. Root position at emergence on the corm followed an asymptotic function of corm dry weight, so that the age of each root at a given time could be deduced from its position. Root diameter at emergence was related to the position of the roots on the corm, with younger roots being thicker than older ones. However, root diameters were not constant along a given root, but instead decreased with the distance to the base; roots appear to be conical in their basal and apical parts. Root growth directions at emergence were variable, but a high proportion of the primary roots emerged with a low angle to the horizontal. Further research is needed to evaluate whether these initial trajectories are conserved during root development. Results presented in this study are in good agreement with those reported for other monocotyledons such as maize and rice. They give quantitative information that will facilitate the development of models of root system architecture in banana.

Effects of nitrogen (N) source and concentration on root system architecture and receptivity to mycorrhizal infection were studied in seedlings of Atlas cedar (Cedrus atlantica Manetti) grown in root observation boxes in a controlled-environment chamber. Nitrogen was supplied in a solution containing either NO3-; or NH4+ at a concentration of either 0.25 or 5.0 mM. Root extension was recorded twice weekly by tracing the roots growing in contact with the transparent face of the root observation box. Among treatments, lateral root production and branching density were greatest with 5.0 mM NO3-. Inoculation with mycelium of Tricholoma cedrorum Malencon was carried out 3 months after the start of the N treatments. The highest percentage of mycorrhizal roots, and the greatest amounts of living mycelium (estimated by the ergosterol assay) were observed in the NO3- treatments. Differences in root branching density among the N treatments were insufficient to explain the observed differences among treatments in the extent of mycorrhizal infection of seedlings.

To describe the different types of geotropic reactions of hevea (Hevea brasiliensis), young seedlings were cultivated in root observation boxes and submitted to a double gravistimulation (90 degrees rotation of the minirhizotrons in the vertical plane). It was demonstrated that the taproot is a strongly orthogeotropic organ since it resumed rapidly its prestimulation vertical position. Morphological and morphogenetic modifications were associated with the geotropic response: reduced speed of growth coupled with a reduction of the apical diameter as well as an alteration of ramification density in the curving zone and the following one. Early secondary roots showed a somewhat reduced orthogeotropism that was weaker as the growth direction before gravistimulation was more distant from the vertical. Secondary roots of the acropetal sequence were semiplagiotropic, that is only those roots oriented upward after the gravistimulation resumed, more or less, the original direction. Tertiary roots didn't respond to the gravistimulation and therefore were ageotropic. Complementary observations conducted in large laboratory rhizotrons showed that late forming secondary roots were plagiotropic in their younger stages, thereafter loosing most of their sensitivity to gravity. Quaternary roots were ageotropic. On the basis of these data, a geotropic gradient was defined within the hevea root system, where the strongly responding taproot and late secondary roots are opposed to the weakly or nonresponding tertiary and quaternary roots. Functional significations of the differential geotropic reactions in different hevea root types are discussed.

The growth patterns of the first-order lateral roots of young oak (Quercus robur L.) tree seedlings were studied and related to variation in apical diameter. Seven seedlings were grown in root observation boxes and monitored daily for 6 wk. Apical diameters were measured daily on a sample of 48 lateral roots. A principal component analysis performed on the data set for 479 lateral roots showed that growth patterns were characterized by two major features. First, they could be described by a general growth potential (first factorial, 80% of the total variability) which was related to growth rate and growth duration. Second, but much less important (second factorial axis, 15% of the total variability), there was a distinction between early-growing roots (growing fast just after emergence and stopping early), and late-growing roots (having a low growth rate at emergence and a higher growth rate later). This growth pattern typology was related to the time-dependent variation in apical diameter. On almost all the roots, the apical diameter tended to decrease after emergence. On short roots (with a low growth potential) the initial apical diameter was low and its decrease was steep. Conversely, long roots had a greater initial diameter and tended to maintain it at a higher level. The so-called late-growing roots had a large apical diameter but a low growth rate in the early stages, possibly because of the between root competition for growth factors. The interest of the apical diameter as a morphological marker of sink strength, and the interactive relationships between growth rate, apical diameter and sucrose supply are discussed.

Plasma testosterone (T) and dihydrotestosterone (DHT) were measured in the plasma of otherwise healthy men ages 60-90 who had prostate hyperplasia. The androgens were measured by specific radioimmunoassays using paper and celite column chromatography. In the elderly subjects, plasma T was 466+/-35 (SE) ng per 100 ml which is reduced (p less than 0.05) as compared with values from younger men. In contrast, DHT levels were elevated when compared with values from men ages 20-39, 89 (53-152) versus 49 (33-74) 95% confidence ng per 100 ml. Analysis of data by the Mann Whitney U test demonstrates that the groups are different (p less than 0.001). These studies indicate that DHT levels and T/DHT ratios are altered in unstressed elderly men with BPH. Further study is necessary to delineate the source of DHT and whether these altered androgen levels are the cause of prostate hypertrophy or an unrelated effect of aging.

The splanchnic extraction and interconversion of testosterone and dihydrotestosterone (DHT) were studied in 7 healthy men (ages 29-46 years) undergoing cardiac catheterization. During a constant infusion of [1,2-3H]testosterone and [4-14C]DHT, the arterial and hepatic vein blood samples were taken and radioactive and non-radioactive testosterone and DHT were determined. Metabolic clearance rate (MCR), splanchnic extraction (SE), splanchnic clearance (SC), extrasplanchnic clearance (ESC), transfer constant in blood (T-DHT rhoBB) and transfer constant across the liver (T-DHT rhoSB) were calculated. The MCRT was 952 +- 172 (mean +- SD) 1/day and MCRDHT was 764 +/- 67 1/day in agreement with data from non-catheterized subjects. SET was 68.8 +/- 7.1% (mean +/- SD) and SEDHT was 37.6 +/- 5.9%. SET was significantly greater than SEDHT (P less than 0.001). The calculated SCT and ESCT were 638 +/- 112 (mean +/- SD) 1/day and 314 +/- 190 1/day, respectively. SCDHT and ESCDHT were 343 +/- 95 (mean +/-SD) 1/day and 421 +/-105 1/day, suggesting that a major fraction of testosterone is metabolized in the splanchnic organs and a higher fraction of DHT is metabolized in extrasplanchnic organs. In the interconversion study, overall conversion of testosterone to DHT in blood (T-DHT rhoBB) was 4.0 +/- 0.6% (mean +/- SD). No evidence for a net appearance of DHT by either mass or specific activity analysis in hepatic vein blood was observed in any infusion leading to the conclusion that the overall contribution of testosterone to circulating DHT from the liver (T-DHTrhoSB) was undetectable. This work indicates that conversion of testosterone to DHT occurs entirely in extrasplanchnic tissue in man.

Tritiated testosterone and [14C]dihydrotestosterone (DHT) were administered by constant iv infusion into five young and five elderly men undergoing diagnostic cardiac catheterization. The radioactivity concentrations of free and conjugated DHT in arterial and hepatic vein blood samples were then determined. The analysis of the 3H:14C ratio of free DHT in arterial and hepatic vein blood showed that in both groups, the 3H:14C ratio of free DHT was the same in arterial and hepatic vein blood, indicating that splanchnic tissue is not the source of blood DHT from testosterone. This is in agreement with data that the transfer constant across the liver ([rho]T-DHT SD) was undetectable. In both young and elderly men, a significant increase of the 3H concentration of DHT glucuronide in hepatic vein blood was observed, indicating that the splanchnic compartment could be the site of production of DHT glucuronide. The 3H:14C ratio of DHT glucuronide was much higher than that of free DHT in both groups, suggesting that DHT glucuronide is derived from the blood testosterone pool, and most of the DHT from testosterone seems to be conjugated before mixing with blood DHT. This study indicates that a large fraction of DHT produced in the liver from testosterone is efficiently conjugated or further metabolized, and this results in the lack of splanchnic production of free DHT in men.

The splanchnic extraction and interconversion of testosterone (T) and dihydrotestosterone (DHT) were studied in 5 elderly men undergoing cardiac catheterization using a constant infusion of [1,2-3H] testosterone and [4-14C] DHT. Metabolic clearance rate (MCR), splanchnic extraction (SE), splanchnic clearance (SC), extrasplanchnic clearance (ESC), transfer constant in blood ([p] T-DHT BB) and transfer constant across the liver ([p] T-DHT SB) were calculated. The MCRT was 675 +/- 108 (mean +/- SC) L/day and MCRDHT was 409 +/- 68 L/day. SET was 45.9 +/- 7.0% and SEDHT was 18.5 +/- 5.4%. When these values are compared with those recently reported by us for normal men, there is a 1/3 reduction in SET and 1/2 reduction for SEDHT in elderly men. The calculated SCT and ESCT were 355 +/- 72 L/day and 320 +/- 86 L/day, respectively. SCDHT and ESCDHT were 145 +/- 48 L/day and 263 +/- 77 L/day respectively, suggesting that a major fraction of DHT is metabolized in extrasplanchnic organs. No evidence for a net appearance of DHT by either mass or specific activity analysis in hepatic vein blood was observed indicating that the splanchnic compartment does not contribute DHT into the circulation either by de novo synthesis or via conversion from testosterone. This work indicates that conversion of testosterone to DHT in elderly men occurs entirely in extrasplanchnic tissue.

A rapid and relatively simple, but specific, radioimmunoassay for the potent androgen, androstanediol (3 alpha-diol), is described. Despite the availability of a nonspecific C-19 androgen antibody requiring a 17 beta-hydroxy group, androstanediol can be measured in plasma by prior purification of a plasma solvent extract using a Celite microcolumn. Values obtained do not differ from those previously reported using more complicated chromatographic techniques.