Renal tumor biopsy does not increase the risk of surgical complications of minimally invasive partial nephrectomy.

BACKGROUND: For patients with cT1 renal lesions, Partial Nephrectomy (PN) is the gold standard treatment. However, 20% of small renal masses are benign, situation in which the PN is an overtreatment. The percutaneous Renal Tumor Biopsy (RTB) may lower the risk of overtreatment as there is a 90% concordance rate on histotype between the RTB and the final pathology. It has been suggested that the RTB could increase the difficulty of the PN and increase the risk of surgical complications. OBJECTIVE: To compare surgical outcomes and complications of PN with or without previous RTB. DESIGN, SETTING, AND PARTICIPANTS: monocentric retrospective review of patients who underwent laparoscopic or robotic-assisted PN between January 2012 and December 2019. MEASUREMENTS: perioperative complications were recorded using Clavien-Dindo classification, peroperative data included operative time, clamping time and blood loss, and histological outcomes of RTB and PN. RESULTS AND LIMITATIONS: In total, 163 patients were included in our study. There were significantly less benign lesions in PN with prior RTB: 7% (4/56) vs. 20% (22/107) without prior RTB (P=0.03). There were no significant differences regarding Clavien-Dindo>2 perioperative complications with respectively 7% (4/56) vs. 10% (11/107) (P=0.57). Same goes for peroperative data such as duration of surgery (P=0.81), warm ischemia (P=0.07) and blood loss (P=0.13). CONCLUSIONS: RTB does not increase the risk of surgical complications of PN and may reduce the risk of small renal masses overtreatment.

Renal Tumor Biopsy: Rationale to Avoid Surgery in Small Renal Masses.

PURPOSE OF REVIEW: The use of renal tumor biopsy (RTB) for small renal masses (SRMs) in daily practice, although safe and accurate, is unusual. Considering the large number of benign tumors in patients with renal masses < 4 cm, some patients with benign tumors are directly referred for surgery instead. This study aimed to report the diagnostic rates of RTB, determine the concordance with surgical pathology, and assess the number of procedures that could have been avoided. We retrospectively studied 255 patients who underwent RTB at our institution in 2010-2019. Of them, 73 were excluded from the analysis (exclusion criteria: > 4 cm, cystic lesion, missing data). The remaining 182 with undetermined SRMs ≤ 4 cm underwent RTB under computed tomography guidance. RECENT FINDINGS: Biopsies were diagnostic in 154/182 (84.6%) cases. Of the non-diagnostic biopsies, 11 were diagnostic when repeated. When RTB was performed of all undetermined SRMs, active treatment (surgery or cryotherapy) was avoided in 50/182 patients (27.5%) because of a benign diagnosis, while 9/182 patients (4.9%) underwent surveillance after a shared multidisciplinary decision. The overall diagnostic rate was 90.6%. All adverse events (approximately 4%) were Clavien-Dindo grade I and did not require active treatment. RTB histology results and nuclear grade were highly concordant with the final pathology (96% and 86.6%, respectively). On univariate logistic regression analysis, male sex was the only contributing factor of diagnostic biopsy. RTB of SRMs should be performed more frequently as part of a multidisciplinary decision-making process since it avoided unnecessary surgical treatment in 1 of 3 patients in our institution.

[Appendicovesicostomy (Mitrofanoff procedure) in children: Long-term follow-up and specific complications]. / Dérivations urinaires continentes trans-conduit selon Mitrofanoff chez l'enfant : suivi à long terme et complications spécifiques.

OBJECTIVE: In children, intermittent catheterization by appendicovesicostomy according to Mitrofanoff is an interesting alternative to the urethral approach. Objective of the study was to evaluate the rate of appendicovesicostomy's specific complications. METHOD: From 1997 to 2017, data on children treated and followed for an appendicovesicostomy in an academic institution were collected retrospectively. Rates of surgical complications specifically encountered on appendicovesicostomy, time of onset, frequency, and necessity of surgical reinterventions have been reported. RESULTS: Thirty-four patients were operated on and followed for a median of 6.2 years [0.3-24]. Fifty percent had a complication, occurring after a median of 8 months [2-90], and 38% required at least one surgical revision. If complication occurred, adjustment of medical treatment and intermittent catheterization was effective in 12% of patients, endoscopic or over-fascial surgery was necessary in 17% of cases, and under-fascial revision in 21% of cases. Median time to complication was 4 months [1-90] after creation or revision of appendicovesicostomy. Thirty-height percent of difficult channel catheterization were reported, of which 46% were over or under-fascial stenosis. Inaugural urinary incontinence was 18%, and only 9% if using the appendix. At the end, 97% of appendicovesicostomy were continent. CONCLUSIONS: Appendicovesicostomy is a high risk of complications and postoperative revisions surgery, in order to have a functional continent channel. LEVEL OF EVIDENCE: 4.

[Fasciae latae perforator flap for breast reconstruction: An attractive alternative in case of DIEP contraindication]. / Le lambeau perforant de fascia lata en reconstruction mammaire : une option intéressante en cas de contre-indication au DIEP.

The musculocutaneous tensor fascia latae flap was one of the first free flaps described. It is possible to harvest a flap with the same skin paddle, vascularized by a septo-cutaneous perforator running through the tensor fascia lata muscle septum and coming from the ascending branch of the lateral circumflex femoral artery. The DIEP is currently the workhorse of autologous breast reconstruction, but there are some contraindications. The septo-cutaneous tensor fascia latae perforator flap may be an alternative for women with lateral upper thigh lipodystrophy. Between 2010 and 2014, three flaps have been performed in two patients for delayed breast reconstruction (one case of unilateral reconstruction, and one bilateral). Perforators were identified by preoperative angiography. The intervention was performed in a two-team approach, in only one operative position. Perforators were located in the horizontal axis of the upper rim of the pubis bone. One perforator artery was dissected for each flap. The mean caliber of the pedicle was 2.8mm, and the mean length was 6.4cm. The operative time was 240minutes for unilateral flap, 375minutes for bilateral flap. There was no case of total or partial necrosis, or complications on the donor site. Cosmetic results were considered satisfying by patients and surgeons with the reconstructed breast as well as the donor site. Septo-cutaneous fascia lata perforator flap is an attractive flap for breast reconstruction in patients with DIEP contraindication and lateral upper thigh lipodystrophy. It has many advantages: easy to harvest, length and calibre of the pedicle, double team approach, only one operating position, quality of reconstruction. It is necessary to carry out a larger series of cases to study the complication rate in the donor site.

[Cutaneous loxoscelism, about an exceptional observation of 9 consecutive cases]. / Le loxoscelisme cutané, à propos d'une observation exceptionnelle de 9 cas consécutifs.

INTRODUCTION: Loxosceles spiders are ubiquitous and responsible for many cases of envenomation in the world. The kind rufescens is present in the Provence and Occitan regions in France. During the summer 2015, we faced many Loxosceles rufescens cases of bites having led to extensive integumental necrosis whose features and singular evolution seems important to report. MATERIAL AND METHODS: We report the cases of nine patients who experienced a spider bite in the summer of 2015 in the Languedoc Roussillon. RESULTS: Of nine patients, eight patients had skin necrosis and five required surgical care. Five patients had a fever and had five other general signs such as important asthenia, joint pain, nausea and dizziness. CRP was very low normal in all patients. Finally, five of the nine patients reported a residual pain. DISCUSSION: L. rufescens is a small spider (7 to 15mm in diameter) having a cytotoxic venom. Loxoscelism diagnosis is usually made by removing a front necrotic skin lesion. Of systemic loxoscelism that have been described, some American species had fatal outcomes. The treatment remains controversial with various options: surgery, antibiotics, antihistaminics, antivenom. CONCLUSION: The diagnosis must be made in endemic areas when confronted to a necrosic integumentary infectious rapidly progressive, unresponsive to antibiotic treatment associated with atypical general signs.

[Oncologic and perioperative outcomes of robot-assisted radical cystectomy: A single-center prospective series]. / Résultats oncologiques et périopératoires de la cystectomie totale robot-assistée pour cancer : une série prospective monocentrique.

INTRODUCTION: The aim of this study was to report perioperative and oncological outcomes of robot-assisted radical cystectomy (RARC) in a single-center series and to evaluate the impact of the experience on perioperative outcomes. METHODS: Between March 2012 and January 2016, 41 patients underwent RARC associated with extended pelvic lymphadenectomy for muscle-invasive bladder cancer. All RARC included were performed by a single-surgeon in one center. Perioperative and oncological datas were collected prospectively. Recurrence-free (RFS), overall (OS) and cancer-specific survivals (CSS) were estimated using the Kaplan-Meier Method. The impact of the experience on perioperative data was estimated using Spearman's correlation test. RESULTS: Mean age was 67,7years (±10.6). Most patients underwent neoadjuvant chemotherapy (73.2%). Mean operative time and mean estimated blood loss were respectively 319.5minutes (±85.3) and 662.5mL (±360.9). Eight patients needed perioperative blood transfusion (19.5%). Conversion to open surgery was necessary in 3 cases (7.3%). Ileal neobladder was performed in 26.8% of the cases (54.5% being performed intracorporeal), and non-continent urinary diversion in 73.2%. Mean nodal yield was 17.7 (±9.3). Positive surgical margins were observed in 1 patient (2.3%). Mean length of stay was 13.2 days (±9.8). Postoperative complication rate was 46,3%. After a median follow-up of 16months, estimated 2 year-OS and CSS were respectively 62 and 76.1%. Estimated 2-year RFS was 67.6%. Perioperative outcomes improved with experience with a significant decrease in operative time (P=0.04) and a significant increase of nodal yield (P=0.05). CONCLUSION: In this single-center prospective study, satisfactory perioperative and oncological outcomes after RARC were observed despite the learning curve. Perioperative outcomes improved with surgeon's experience. Further studies are needed to confirm these findings. LEVEL OF EVIDENCE: 4.

Carcinoma of the salivary glands: guidelines and case report of sustained remission with docetaxel.

WHAT IS KNOWN AND OBJECTIVE: Salivary glands tumours are rare neoplasms for which there are few clinical trials. The most common malignant parotid tumour is the mucoepidermoid carcinoma. High-grade mucoepidermoid carcinomas are highly aggressive tumours. The initial therapy of localized disease is known, but when there is a recurrence, several options are possible and chemotherapy is generally reserved for palliative treatment. We comment on published guidelines and report a case of sustained remission with docetaxel. CASE SUMMARY: Our case concerns a 64-year-old woman with a high-grade mucoepidermoid carcinoma of the parotid gland with local recurrence treated with docetaxel 50 mg/m² every 15 days. After the sixth cycle, a complete remission was observed on CT-scan. The tolerability was excellent. After 2 years of docetaxel, the patient was still in complete remission. WHAT IS NEW AND CONCLUSION: Docetaxel is an active drug for the treatment of mucoepidermoid carcinoma of salivary glands. A prospective study should confirm these data.

Application of ARISA to assess the influence of salt content and cation type on microbiological diversity of Cheddar cheese.

UNLABELLED: The structure and dynamics of microbial populations play a significant role during cheese manufacture and ripening. Therefore, fast and accurate methods for identification and characterization of the microbial populations are of fundamental importance to the cheese industry. In this study, we investigate the application of the automated ribosomal intergenic spacer analysis (ARISA) for the assessment of the microbial dynamics in cheeses differing in salt cation level and type. We developed a database of the observed and theoretical length of the 16S-23S intergenic spacer of common lactic acid bacteria (LAB) found in cheese and used the database to describe the structure and dynamics of microbial populations during ripening. Salt content and cation concentration did not significantly influence the overall bacteria structure, except that lower salt levels resulted in enhanced starter survival. Presence of nonstarter LAB was detected by ARISA and denaturing gradient gel electrophoresis (DGGE) after 3 months for all the cheeses analysed. ARISA used as fingerprinting method, proved to be a rapid and inexpensive technique for the discrimination of LAB in cheese and demonstrated higher resolution and performance in comparison with DGGE. SIGNIFICANCE AND IMPACT OF THE STUDY: Microbial communities play important roles during cheese making and ripening, hence rapid inexpensive methods to characterize this microbiota are of great interest to both academic and industrial scientists. The application of automated ribosomal intergenic spacer analysis (ARISA) was used to examine the microbial ecology of Cheddar cheese differing in salt level and type. ARISA is well suited to the analysis of the microbial ecology of cheese during ripening. Additionally, the results confirm that salt concentration influences starter culture survival in the cheese matrix, while significant differences were not observed in the nonstarter lactic acid bacteria.

Rare diseases with oral components: care course and quality of life.

AIM: To describe links between the care course of individuals suffering from rare diseases and socio-behavioural risk factors and to ascertain the impact of dental conditions on the quality of life. DESIGN: A cross-sectional comparative study involving self-reported questionnaire was performed. Care course was evaluated using predisposing, enabling and needs factors. The impacts of dental conditions on quality of life were measured with the OHIP 14 questionnaire. Proportions were compared by Chi-square test. Logistic regression for multivariate analysis assessed statistical association between variables. RESULTS: Responses were received from 355 subjects (mean age 36.9 years, 67.6% females). Thirty-three rare diseases were recorded. Respondents were classified as group A, individuals suffering from rare diseases with a dental component (n=207, 58.3%), and group B, without dental component. Group A reported earlier diagnosis, more positive attitude toward dentists, functional limitation and higher prosthetic treatment needs. Only 17.4% of subjects having fewer than 20 teeth wear prosthetics. A higher percentage of individuals claiming pain, physical disability, psychological discomfort and social disability, was found among group B (p<0.001). Logistic regression analysis retained two impact factors: psychological disability (Exp(B)=8.66; 95% CI 1.86-40.34) and social wellbeing (Exp(B)=0.06; 95% CI 0.02-0.215). CONCLUSION: Rare diseases with a dental component benefited from earlier identification of symptoms. Dentists could contribute to patients' quality of life by helping in early diagnosis, reducing functional limitation and improving social wellbeing.

Collective aeromedical evacuations of SARS-CoV-2-related ARDS patients in a military tactical plane: a retrospective descriptive study.

After the appearance of the COVID-19 pandemic in France, MEROPE system was created to transform the military tactical ATLAS A400M aircraft into a flying intensive care unit. Collective aeromedical evacuations (aero-MEDEVAC) of patients suffering from SARS-CoV-2-related acute respiratory distress syndrome was performed from June to December 2020. A total of 22 patients were transported during seven missions. All aero-MEDEVAC was performed in safe conditions for patients and crew. No life-threatening conditions occurred during flight. Biohazard controls were applied according to French guidelines and prevented crew contamination. Thanks to rigorous selection criteria and continuous in-flight medical care, the safe transportation of these patients was possible. To the best of our knowledge, this is the first description of collective aero-MEDEVAC of these kinds of patients using a tactical military aircraft. We here describe the patient's characteristics and the flight's challenges.

Management of incidental discovery of microscopic squamous cell carcinoma in zones of osteoradionecrosis of the mandible.

OBJECTIVES: Osteoradionecrosis (ORN) of the mandible is a common complication of head and neck radiotherapy and often requires surgical treatment. Squamous cell carcinoma (SCC) can be exceptionally discovered within zones of ORN on histological examination of the operative specimen. The authors discuss the management of these lesions based on a short patient series. MATERIALS AND METHODS: This single-centre retrospective study was based on patients managed between 2012 and 2014 for ORN with incidental discovery of microscopic SCC. RESULTS: Five patients with incidental discovery of microscopic SCC in a zone of ORN of the mandible were included in this study. The mean time to onset of ORN after the end of radiotherapy for locally advanced SCC of the oral cavity or oropharynx was 42 months. Surgical treatment consisted of marginal or segmental mandibulectomy with free flap reconstruction. No recurrence was observed with a mean follow-up of 35 months [24-46]. CONCLUSION: The incidental discovery of microscopic SCC in a zone of ORN of the mandible is a rare event and has not been reported in the literature. Optimal management cannot be reliably defined due to the lack of data in the literature, but the present study supports careful histological examination of ORN specimens. Treatment must be as conservative as possible to avoid excessively invasive surgery.

[The role of electromagnetic navigation bronchoscopy in the diagnosis of peripheral pulmonary lesions]. / Place de la navigation électromagnétique endobronchique pour le diagnostic de lésions pulmonaires périphériques.

INTRODUCTION: Electromagnetic navigation bronchoscopy (ENB) is a recent, minimally invasive procedure utilized to guide endoscopic diagnostic tools to peripheral pulmonary nodules. The place of this technology among other diagnostic procedures remains uncertain. METHOD: We analyzed our 30 first months of ENB used in the diagnosis of 106 lesions in 101 patients, from June 2016 to December 2018. Follow-up and final diagnosis was completed for 95 lesions (90%). RESULTS: ENB was performed for 3.5% of all patients referred for abnormal findings on pulmonary imaging, and represented 19% of second line procedures for peripheral pulmonary lesions. Procedures were performed under general anesthesia, with a mean duration of 35min. The sensitivity of ENB was 64% (95%CI: 52-74%) for lesions with a mean diameter of 21mm, with an improvement over time (sensitivity 69% in the last 18 months). The presence of a bronchus within the lesion (bronchus sign) was associated with an increased sensitivity of 74%. Pneumothorax occurred in 5 patients (5%) of which 4 required drainage. There was no hemoptysis, and no death related to the procedure. CONCLUSION: ENB is a minimally invasive procedure reaching acceptable sensitivity in the most difficult patients. ENB can be recommended for the diagnosis of peripheral pulmonary nodules when no other procedure is successful or possible. Its use as a first choice procedure is, for the moment, limited by the cost, but must be weighed against that of non-diagnostic procedures, and the cost of complications of trans-thoracic lung biopsies.

Oxaliplatin, 5-Fluorouracil and Nab-paclitaxel as perioperative regimen in patients with resectable gastric adenocarcinoma: A GERCOR phase II study (FOXAGAST).

BACKGROUND: 5-Fluorouracil (5-FU) and platinum-based perioperative chemotherapy is standard of care for resectable gastric adenocarcinoma (RGA). Nanoparticle albumin-bound (Nab-) paclitaxel is active in advanced disease but has never been evaluated in the perioperative setting. The objective was to evaluate the efficacy of Nab-paclitaxel in combination with FOLFOX for RGA patients. METHODS: We performed a non-randomised, open-label, phase II study. RGA patients were assigned to receive neoadjuvant Nab-paclitaxel (150 mg/m2) and FOLFOX q2w for six cycles. Six additional post-operative cycles were kept at the investigator's discretion. The primary end-point was complete pathological response (tumour regression grade [TRG1]) rate. According to Fleming design, 49 patients were required to test H0 (10% TRG1) and H1 (25% TRG1). To reject H0, TRG1 had to be achieved in 8 patients. RESULTS: Forty-nine patients were included. Median number of neoadjuvant chemotherapy cycles was 6 (range, 3-6). Median dose intensity for Nab-paclitaxel, oxaliplatin and 5-FU was 96% (38-103%), 97% (47-103%) and 99% (50-112%), respectively. Surgery could not be performed in 5 (10.2%) patients. Tumour resection was R0 for 42 of 44 (95.5%) patients. Pathological review classified tumours as TRG1 to TRG5 for 8 (16.3%), 11 (22.5%), 4 (8.2%), 18 (36.7%) and 3 (6.1%) patients, respectively. Grade 3 or worse toxicities during neoadjuvant chemotherapy were non-febrile neutropenia (20.4%), nausea (8.2%), diarrhoea (8.2%) and neuropathy (6.1%). Of 44 patients, 14 (31.8%) experienced surgery-related complications and three (6.8%) died of surgical complications. CONCLUSION: This regimen shows promising activity. Toxicity is manageable but a meaningful rate of surgical complications was observed. This strategy deserves investigation in phase III studies.

[What is the most relevant definition of orthostatic hypotension: systolic blood pressure drop, diastolic blood pressure drop, or both?]. / Quelle baisse de pression artérielle choisir pour définir l'hypotension orthostatique chez le sujet âgé: Chute de la pression artérielle systolique, de la diastolique ou des deux?

UNLABELLED: The agreed definition of orthostatic hypotension (OH) is a drop of 20 mmHg systolic and/or 10 mmHg diastolic blood pressure (BP) within the first 3 min of erect posture. For elderly people, a question can be raised about diastolic BP relevance in OH's definition. OBJECTIVE: To determinate HO's prevalence and risks factors considering systolic blood pressure (SBP)'s drop, or diastolic blood pressure (DBP)'s drop, or either. METHODS: We assessed OH for 554 consecutive, ambulatory, elderly subjects, attending a geriatric outpatient clinic. OH was defined as a SBP drop>20mmHg (SBP-OH), or a DBP drop>10 mmHg (DBP-OH), or a drop in either (SBP. DBP-OH). OH's prevalence and risks factors were determined. RESULTS: In this population, 76 +/- 6 years of age, (70% hypertension), SBP-OH's prevalence was 17%, DBP-OH's prevalence was 12% and SBP. DBP-OH's prevalence was 25%. OH's risks factors varied considering OH's definition. After adjusting for significant determinants, SBP-OH's risk factors were: Antihypertensive therapy (OR=2.95; IC 95%: 1.21-4.04), age>75years (OR=2.11; IC 95%: 1.22-3.66), anti-hypertensive poly therapy (OR=2.01; IC 95%: 1.39-2.92) and SBP level (OR=1.16; IC 95%: 1.01-1.33). Considering DBP-OH, the only significant risk factor was DBP's level (OR=2.64; IC 95%: 1.89-3.68). SBP. DBP-OH was only determined by anti-hypertensive poly therapy (OR=1.61; IC 95%: 1.13-2.29) and DPB level (OR=1.32; IC 95%: 1.08-1.60). CONCLUSION: For elderly people, OH's prevalence and risks factors vary considering OH's definition. SBP's drop seems to be more relevant than DBP's drop. A long term follow up is necessary to determine if SBP-OH is correlated with HO' s side effects and to establish the dangerous level of SBP' s drop.

Incidental cervical metastases from thyroid carcinoma during neck dissection.

OBJECTIVES: To quantify and discuss the prevalence of unsuspected thyroid lymph node metastases discovered in specimens from neck dissection for head and neck squamous cell carcinoma (HNSCC) and discuss the impact on patient management. STUDY DESIGN: Retrospective study between May 2004 and January 2007. SETTING: University hospital. METHODS: Pathological analysis of cervical lymph node dissection performed during surgery for HNSCC in a total of 349 neck dissections in 266 consecutive patients. RESULTS: Twenty-one patients showed metastatic lymph nodes from thyroid cancer (prevalence 7.9%): 13 cases were metastatic from a papillary thyroid carcinoma and 8 cases from a follicular carcinoma. In 5 of the 21 patients, classical dissection was associated to recurrent nerve dissection and unilateral lobectomy; no thyroid carcinoma was found. Thirteen patients received radiotherapy for HNSCC. Follow-up comprised annual ultrasonographic examination of the neck and thyroid in these 21 patients. Total thyroidectomy was decided on in 5, with discovery of 3 micro-papillary thyroid carcinomas, in a single patient (complementary 131I treatment). No thyroid carcinomas were found for the other 4 patients. No patients died from thyroid carcinoma during follow-up (mean: 41 months). CONCLUSION: The prevalence of lymph node metastasis from thyroid carcinoma in cervical lymph node dissection during treatment of HNSCC seems higher (7.9%) than rates reported in the literature (0.3 to 1.6%). This may be due to the histopathological methods employed. Management of patients should be discussed in the light of thyroid ultrasonography and prognosis of HNSCC.

Modification of arterial elastin in vivo. Effects of age and diet on changes in the N-terminal amino acid content of aorta elastin.

We have previously demonstrated that aorta elastin, a highly crosslinked protein, does not undergo turnover that is easily measured in vivo. Therefore, it was hypothesized that when proteolysis of elastin occurs, a positive increase in N-terminal amino acids should result. Such an increase would represent elastin-derived fragments held covalently in situ. A cyanate carbamylation procedure was used to estimate the changes in N-terminal amino acids in aorta elastin. To provide tissue for the studies, Japanese quail (3 weeks old) were fed diets with or without the addition of 1% cholesterol. It was found that, in normal birds, the number of N-terminal amino acid residues increased from two to approximately three residues per 800 total residues (or mole of tropoelastin) throughout sexual development (3 to 8 weeks, post-hatching), with little increase thereafter. In hypercholesterolemic birds, the rate of appearance of new N-terminal residues, particularly glutamine or glutamic acid, appeared enhanced throughout early development, but by sexual maturity the number of N-terminal amino acid residues in aorta elastin from cholesterol-fed birds was similar to that for the control birds. For each of the elastin samples analyzed, approximately one residue of glycine was recovered per 800 total residues. Other amino acids that predominated as N-terminal residues were serine, aspartic and glutamic acids.

Aorta elastin turnover in normal and hypercholesterolemic Japanese quail.

The turnover and degradation of mature elastin from the aortae of Japanese quail were estimated following injection with L-[U-14C]lysine by measuring the changes in specific activity of L-[U-14C]lysine and 14C-labelled desmosine and isodesmosine (crosslinking amino acids derived from lysyl residues) in elastin over a 39-week period. Only 5% of the variation in radioactivity could be attributed to changes in time. Therefore, it was concluded that the best estimates of mature elastin turnover are only quantifiable in years. Dietary cholesterol in amounts sufficient to induce plaque formatioin and fragmentation of the elastic lamina in the aorta did not significantly influence turnover time. It would appear that once the total pool of elastin in aorta is stabilized as mature fibers it is not subject to proteolysis or resynthesis of sufficient magnitude to result in measurable turnover.