Traumatic injury to vascular prosthetic anastomosis: A case report and diagnostic approach.

INTRODUCTION: Traumatic injury of a vascular prosthesis-to-prosthesis anastomosis leading to an extravasation and pseudoaneurysm is rare. If not identified the complications associated with this condition can lead to high morbidity and mortality and require surgical treatment. CASE: We describe a patient who presented with a tear in prosthesis-prosthesis anastomosis eight years after implantation resulting in a pseudoaneurysm. The patient had a severe fall prior to the non-symptomatic leakage. The complication was successfully treated by re-lining the graft with a new anastomosis at the Department of Vascular and Endovascular Surgery, Kolding Hospital in Denmark. DISCUSSION: Cause of tear is speculated to be due to weakness at site of reconstruction, fabric degradation, and/or degradation of suture material. CONCLUSION: Late prosthesis-prosthesis anastomosis tear caused by a traumatic event is rare. In the event of a late tear, anamnesis and histological analysis of involved material is important.

Declining Incidence of Major Lower-Extremity Amputations in the Northern Danish Region Between 2016 and 2021: The Impact of Diabetes and Preventive Vascular Procedures.

BACKGROUND: Preventing lower-extremity amputations (LEAs) is pivotal. In the present study, we aimed to examine the recent trends in nontraumatic LEAs seen in the Northern Danish Region. METHODS: Using data from the regional Business Intelligence unit, we identified all nontraumatic LEAs (n = 689) performed in people above 50 years of age in the Northern Danish Region between January 2016 and December 2021 (approximately 600,000 inhabitants). Persons with diabetes (n = 26,025) were identified based on International Classification of Diseases-10 codes and data from the National Health Insurance Service Registry, while preventive vascular procedures (n = 1,097) were identified using surgical codes. Major LEA was defined as any amputation above the ankle. Incidence rates were expressed as events per 1,000 person-years. Trends were described as differences between the periods 2016-2018 and 2019-2021. RESULTS: A total of 249 (36%) major LEAs were performed in people with diabetes. People with diabetes were younger (71 vs 77 years, P < 0.001) and more frequently male (70% versus 54%, P < 0.001). Between 2016-2018 and 2019-2021, the incidence of major LEA declined from 1.76 (95% CI: 1.75-1.76) to 1.39 (1.39-1.39) in people with diabetes and from 0.47 (0.47-0.47) to 0.20 (0.20-0.20) in people without diabetes (all P < 0.001). Simultaneously, the incidence of preventive vascular surgery increased from 2.26 (2.26-2.26) to 3.48 (3.48-3.48) in people with diabetes and declined slightly in people without 0.49 (0.49-0.49) to 0.47 (0.47-0.47) (all P < 0.001). CONCLUSIONS: Despite significant declines in major LEA in both people with and without diabetes, most of the decline was driven by a large reduction in major LEAs in people without diabetes.

Atypical fractures of the lower extremities in two patients with rheumatoid arthritis: clinical presentations of presumed methotrexate osteopathy.

We present two patients who developed multiple lower limb stress fractures. Potential causes, such as osteoporosis, malignancies and disturbances in calcium metabolism were investigated. This led the physicians to consider whether methotrexate (MTX) exposure posed a risk of atypical fractures.The association between MTX and lower limb fractures has been described in at least 80 cases in the literature. Stress fractures associated with MTX treatment are atypical of osteoporosis and located in the lower extremities, most often the tibia. The limited data suggest that discontinuation of MTX may improve symptoms and chances of fracture healing, while antiresorptive or osteoanabolic therapies have not proven clinically efficient. It seems evident, however, that the benefits of MTX treatment in rheumatological disease clearly outweigh the risk of MTX osteopathy and related fractures.

Pneumothorax contralateral to traumatic costal fractures.

In this case report, a 19-year-old woman suffered a high-energy trauma to her left side with multiple left-sided fractures, including ribs 8-12, with no pneumothorax on the left side, but a large right-sided pneumothorax. Contralateral pneumothorax is extremely rare in primarily unilateral trauma, especially when no contralateral rib fractures are present. A possible explanation is that of a barotrauma due to increased intrathoracic pressure with external compression. Careful examination of both sides of the body is necessary when evaluating patients with unilateral trauma, as serious organ injury may occur contralaterally.

Statistical Reproducibility of Selective Area Grown InAs Nanowire Devices.

New approaches such as selective area growth (SAG), where crystal growth is lithographically controlled, allow the integration of bottom-up grown semiconductor nanomaterials in large-scale classical and quantum nanoelectronics. This calls for assessment and optimization of the reproducibility between individual components. We quantify the structural and electronic statistical reproducibility within large arrays of nominally identical selective area growth InAs nanowires. The distribution of structural parameters is acquired through comprehensive atomic force microscopy studies and transmission electron microscopy. These are compared to the statistical distributions of the cryogenic electrical properties of 256 individual SAG nanowire field effect transistors addressed using cryogenic multiplexer circuits. Correlating measurements between successive thermal cycles allows distinguishing between the contributions of surface impurity scattering and fixed structural properties to device reproducibility. The results confirm the potential of SAG nanomaterials, and the methodologies for quantifying statistical metrics are essential for further optimization of reproducibility.

Large retrorectal spindle cell sarcoma: A case report and brief review of the literature.

Large retrorectal tumors are rare and often a diagnostic and surgical challenge due to their anatomical location. We report the case of a 55-year-old patient with weight loss and changed bowel habits, where digital rectal examination revealed a retrorectal mass raising suspicion of a tumor. Magnetic resonance imaging (MRI) and computed tomography (CT) showed a large retrorectal tumor and histopathology after surgical resection showed undifferentiated spindle cell sarcoma. This tumor type has not been previously reported as the etiology of large retrorectal tumors. We discuss the implications of diagnostic imaging, especially MRI, in the approach to diagnosis and surgical treatment of retrorectal tumors with reference to the scientific literature and previously reported cases of retrorectal tumors.

Adherence and Persistence to Antiplatelet Therapy in Lower Extremity Peripheral Arterial Disease: A Danish Population Based Cohort Study.

OBJECTIVE: Adherence to antiplatelet therapy is recommended but unexplored in patients with symptomatic lower extremity peripheral arterial disease (PAD). Therefore, this study aimed to determine adherence and persistence to antiplatelet therapy in patients with PAD, defined as intermittent claudication and chronic limb threatening ischaemia. DESIGN: Population based nationwide cohort study. METHODS: This study included all Danish citizens aged ≥ 40 years with a first inpatient or outpatient diagnosis of symptomatic PAD between 2010 - 2017, and who had at least one prescription claim for aspirin and/or clopidogrel within 90 days after diagnosis. Adherence was determined by the proportion of days covered (PDC) during the first year after diagnosis. Persistence was defined as no treatment gap ≥ 30 days between prescription renewals over three year follow up. RESULTS: A total of 39 687 patients were eligible for inclusion, of whom 23 279 (58.7%) claimed a prescription for aspirin and/or clopidogrel within 90 days of diagnosis. Among these, 12 898 (55.4%) were prevalent users, while the remainder comprised new users who initiated the therapy after the index PAD diagnosis. The mean PDC was 74.5% (SD 35.0%) for prevalent users and 60.5% (SD 30.5%) for new users. Adherence increased with age and number of concomitant drugs. The overall one year cumulative incidence treatment discontinuation was 13.0% (95% CI 12.5 - 13.4%) overall, 17.2% (CI 16.6 - 17.9%) for prevalent users, and 7.9% (CI 7.4 - 8.4%) for new users. At three year follow up, the cumulative incidence of discontinuation was 31.5% (CI 30.9 - 32.2%) overall, 44.6% (CI 43.7 - 45.4%) for prevalent users, and 14.6% (CI 13.9 - 15.3) for new users. CONCLUSION: Less than 60% of patients with newly diagnosed symptomatic PAD claimed a prescription for antiplatelet therapy within 90 days of diagnosis, and both adherence and persistence were moderate during the first year after diagnosis. These findings underscore the importance of efforts to improve the initiation and continuation of antiplatelet therapy in patients with PAD.

Risk of Stroke and Myocardial Infarction Among Initiators of Triptans.

Importance: Triptans are contraindicated in patients with ischemic heart disease or previous myocardial infarction, and caution is advised when prescribing these drugs to patients with vascular risk factors. However, controlled observational studies have either shown no association or an apparent lower risk, possibly owing to a channeling of triptans to individuals at low risk of cardiovascular outcomes, and it remains unclear whether avoiding triptan treatment for these patients is meaningful. Objective: To establish whether an association between triptans and ischemic events could be demonstrated using a self-controlled design because this type of design is robust to the previously mentioned type of confounding. Design, Setting, and Participants: All people in nationwide Danish registries who were initiating triptans and all the ischemic events that they experienced were identified. A case-crossover design was used to estimate odds ratios (OR) for associations between first-ever triptan use and ischemic outcomes, comparing triptan exposure in the 2-week period up to the event with four 2-week reference periods. Data were obtained for the period January 1995 to August 2022. Included from the population of Denmark were individuals redeeming a prescription for any triptan and experiencing at least 1 of 3 predefined ischemic outcomes. No one was excluded. Exposure: Initiation of any triptan. Main Outcomes and Measures: Acute myocardial infarction, ischemic stroke, or nonspecified stroke. Results: Identified were a total of 429 612 individuals (median [IQR] age, 38 [28-48] years; 325 687 female [75.8%]) who redeemed a first prescription for a triptan in the study period. Of these patients, 11 (0.003%) had a myocardial infarction with the first triptan prescription in either a focal or referent window (odds ratio [OR], 3.3; 95% CI, 1.0-10.9), 18 (0.004%) had ischemic stroke (OR, 3.2; 95% CI, 1.3-8.1), and 35 (0.008%) had ischemic/nonspecified stroke (OR, 3.0; 95% CI, 1.5-5.9). Case patients had a median age of approximately 60 years and had a high-risk cardiovascular profile. Conclusions and Relevance: Results of this case-crossover study suggest that triptan initiation was associated with higher risk of ischemic stroke and myocardial infarction. For the individual patient with low background cardiovascular risk, the risk of an ischemic event after triptan initiation was very low.

Observing the primary steps of ion solvation in helium droplets.

Solvation is a ubiquitous phenomenon in the natural sciences. At the macroscopic level, it is well understood through thermodynamics and chemical reaction kinetics1,2. At the atomic level, the primary steps of solvation are the attraction and binding of individual molecules or atoms of a solvent to molecules or ions of a solute1. These steps have, however, never been observed in real time. Here we instantly create a single sodium ion at the surface of a liquid helium nanodroplet3,4, and measure the number of solvent atoms that successively attach to the ion as a function of time. We found that the binding dynamics of the first five helium atoms is well described by a Poissonian process with a binding rate of 2.0 atoms per picosecond. This rate is consistent with time-dependent density-functional-theory simulations of the solvation process. Furthermore, our measurements enable an estimate of the energy removed from the region around the sodium ion as a function of time, revealing that half of the total solvation energy is dissipated after four picoseconds. Our experimental method opens possibilities for benchmarking theoretical models of ion solvation and for time-resolved measurements of cation-molecule complex formation.

Cryogenic multiplexing using selective area grown nanowires.

Bottom-up grown nanomaterials play an integral role in the development of quantum technologies but are often challenging to characterise on large scales. Here, we harness selective area growth of semiconductor nanowires to demonstrate large-scale integrated circuits and characterisation of large numbers of quantum devices. The circuit consisted of 512 quantum devices embedded within multiplexer/demultiplexer pairs, incorporating thousands of interconnected selective area growth nanowires operating under deep cryogenic conditions. Multiplexers enable a range of new strategies in quantum device research and scaling by increasing the device count while limiting the number of connections between room-temperature control electronics and the cryogenic samples. As an example of this potential we perform a statistical characterization of large arrays of identical quantum dots thus establishing the feasibility of applying cross-bar gating strategies for efficient scaling of future selective area growth quantum circuits. More broadly, the ability to systematically characterise large numbers of devices provides new levels of statistical certainty to materials/device development.

BMP suppresses WNT to integrate patterning of orthogonal body axes in adult planarians.

Adult regeneration restores patterning of orthogonal body axes after damage in a post-embryonic context. Planarians regenerate using distinct body-wide signals primarily regulating each axis dimension: anteroposterior Wnts, dorsoventral BMP, and mediolateral Wnt5 and Slit determinants. How regeneration can coordinate perpendicular tissue axes without symmetry-breaking embryonic events is not fully understood. Here, we report that the planarian dorsoventral regulator bmp4 suppresses the posterior determinant wnt1 to provide patterning input to the anteroposterior axis. Double-FISH identified distinct anteroposterior domains within dorsal midline muscle that express either bmp4 or wnt1. Homeostatic inhibition bmp4 and smad1 expanded the wnt1 expression anteriorly, while elevation of BMP signaling through nog1;nog2 RNAi reduced the wnt1 expression domain and elevated bmp4 expression. Homeostatic BMP signal perturbation broadly affected anteroposterior identity as measured by expression of posterior Wnt pathway factors, and caused mislocalization of AP-regionalized pharynx progenitors, without strongly affecting expression domains of anterior regulators. Additionally, wnt1 inhibition elevated bmp4 expression in the tip of the tail. Therefore, dorsal BMP signals and posterior wnt1 mutually antagonize for patterning the tail. Furthermore, homeostatic bmp4 RNAi caused medial expansion of the lateral determinant wnt5 and reduced expression of the medial regulator slit. By contrast, nog1;nog2 RNAi restricted wnt5 expression. Double RNAi of bmp4 and wnt5 resulted in lateral ectopic eye phenotypes, suggesting bmp4 acts upstream of wnt5 to pattern the mediolateral axis. These results indicate bmp4 controls dorsoventral information and also, through suppression of Wnt signals, influences anteroposterior and mediolateral identity. Based on related functions across vertebrates and Cnidarians, Wnt and BMP cross-regulation could form an ancient mechanism for coordinating orthogonal axis patterning.

Spermatocytic tumors in 2 patients aged 50 and 77 years: 2 case reports and brief review of the literature.

Testicular cancer is predominantly diagnosed in young men aged 15-35 years. However, there are some rare tumors such as spermatocytic tumors that are seen more often in the older male population. Spermatocytic tumors have previously been known as spermatocytic seminomas in the scientific literature. We report the cases of 2 patients aged 50 and 77 years both diagnosed with spermatocytic tumors. In this paper we will discuss the ultrasound and histopathology features of these tumors and review the literature of spermatocytic tumor cases.

Intrauterine hormonal contraception and risk of breast cancer.

Intrauterine hormonal contraception devices are widely used among Danish women. Cases of breast cancer have been reported in women using the devices and studies have found evidence of an increased risk, but a new meta-analysis did not find an increased risk. The reported relative risks in some of the studies are numerically substantial as quoted in this review, but it is very important that physicians take absolute numbers into account when interpreting risk in order to provide the best guidance of patients with regard to contraception and associated risks.

Wnt signaling in whole-body regeneration.

Regeneration abilities are widespread among animals and select species can restore any body parts removed by wounds that sever the major body axes. This capability of whole-body regeneration as exemplified in flatworm planarians, Acoels, and Cnidarians involves initial responses to injury, the assessment of wound site polarization, determination of missing tissue and programming of blastema fate, and patterned outgrowth to restore axis content and proportionality. Wnt signaling drives many shared and conserved aspects of the biology of whole-body regeneration in the planarian species Schmidtea mediterranea and Dugesia japonica, in the Acoel Hofstenia miamia, and in Cnidarians Hydra and Nematostella. These overlapping mechanisms suggest whole-body regeneration might be an ancestral property across diverse animal taxa.

When the machine is wrong. Characteristics of true and false predictions of Out-of-Hospital Cardiac arrests in emergency calls using a machine-learning model.

BACKGROUND: A machine-learning model trained to recognize emergency calls regarding Out-of-Hospital Cardiac Arrest (OHCA) was tested in clinical practice at Copenhagen Emergency Medical Services (EMS) from September 2018 to December 2019. We aimed to investigate emergency call characteristics where the machine-learning model failed to recognize OHCA or misinterpreted a call as being OHCA. METHODS: All emergency calls were linked to the dispatch database and verified OHCAs were identified by linkage to the Danish Cardiac Arrest Registry. Calls with either false negative or false positive predictions of OHCA were evaluated by trained auditors. Descriptive analyses were performed with absolute numbers and percentages reported. RESULTS: The machine-learning model processed 169,236 calls to Copenhagen EMS and suspected 5,811 (3.4%) of the calls as OHCA, resulting in 84.5% sensitivity and 97.1% specificity. Among OHCAs not recognised by machine-learning model, a condition completely different from OHCA was presented by caller in 31% of the cases. In 28% of unrecognised calls, patient was reported breathing normally, and language barriers were identified in 23% of the cases. Among falsely suspected OHCA, the patient was reported unconscious in 28% of the cases, and in 13% of the false positive cases the machine-learning model interpreted calls regarding dead patients with irreversible signs of death as OHCA. CONCLUSION: Continuous optimization of the language model is needed to improve the prediction of OHCA and thereby improve sensitivity and specificity of the machine-learning model on recognising OHCA in emergency telephone calls.

BMP suppresses WNT to integrate patterning of orthogonal body axes in adult planarians.

Adult regeneration restores patterning of orthogonal body axes after damage in a post-embryonic context. Planarians regenerate using distinct body-wide signals primarily regulating each axis dimension: anteroposterior Wnts, dorsoventral BMP, and mediolateral Wnt5 and Slit determinants. How regeneration can consistently form perpendicular tissue axes without symmetry-breaking embryonic events is unknown, and could either occur using fully independent, or alternatively, integrated signals defining each dimension. Here, we report that the planarian dorsoventral regulator bmp4 suppresses the posterior determinant wnt1 to pattern the anteroposterior axis. Double-FISH identified distinct anteroposterior domains within dorsal midline muscle that express either bmp4 or wnt1 . Homeostatic inhibition bmp4 and smad1 expanded the wnt1 expression anteriorly, while elevation of BMP signaling through nog1;nog2 RNAi reduced the wnt1 expression domain. BMP signal perturbation broadly affected anteroposterior identity as measured by expression of posterior Wnt pathway factors, without affecting head regionalization. Therefore, dorsal BMP signals broadly limit posterior identity. Furthermore, bmp4 RNAi caused medial expansion of the lateral determinant wnt5 and reduced expression of the medial regulator slit . Double RNAi of bmp4 and wnt5 resulted in lateral ectopic eye phenotypes, suggesting bmp4 acts upstream of wnt5 to pattern the mediolateral axis. Therefore, bmp4 acts at the top of a patterning hierarchy both to control dorsoventral information and also, through suppression of Wnt signals, to regulate anteroposterior and mediolateral identity. These results reveal that adult pattern formation involves integration of signals controlling individual orthogonal axes. Author Summary: Systems that coordinate long-range communication across axes are likely critical for enabling tissue restoration in regenerative animals. While individual axis pathways have been identified, there is not yet an understanding of how signal integration allows repatterning across 3-dimensions. Here, we report an unanticipated linkage between anteroposterior, dorsoventral, and mediolateral systems in planarians through BMP signaling. We find that dorsally expressed BMP restricts posterior and lateral identity by suppressing distinct Wnt signals in adult planarians. These results demonstrate that orthogonal axis information is not fully independent and suggest a potentially ancient role of integrated axis patterning in generating stable 3-dimensional adult forms.

Temporal trends in major cardiovascular events following first-time myocardial infarction in the reperfusion era - a Danish nationwide cohort study from 2000 to 2017.

AIM: We investigated temporal trends in major cardiovascular events following first-time myocardial infarction (MI) and trends in revascularization and pharmacotherapy from 2000 to 2017. METHODS AND RESULTS: Using nationwide registries, we identified 120 833 Danish patients with a first-time MI between 2000 and 2017. We investigated 30-day and 1-year mortality and the 1-year risk of first-time admission for heart failure (HF) and recurrent MI. Patients were younger with a higher prevalence of hypertension and diabetes in 2015-2017 compared with 2000-2002. The patients were predominantly male (65.6%), and the median age declined by 3 years through the periods. Percutaneous coronary interventions within 7 days after first-time MI increased significantly (2000: 11.4% vs. 2017: 68.6%; Ptrend < 0.001). Cardiovascular medication after first-time MI changed significantly in the same period. Absolute risks and adjusted rates of outcomes were significantly lower in 2015-2017 compared with 2000-2002: 30-day mortality: 6.5% vs. 14.1% [hazard ratio (HR) 0.52, 95% confidence interval (CI): 0.48-0.55); 1-year mortality 10.7% vs. 21.8% (HR 0.52, 95% CI: 0.50-0.55); recurrent MI: 4.0% vs. 7.8% (HR 0.56, 95% CI: 0.51-0.62); and first-time admission for HF: 2.9% vs. 3.7% (HR 0.82, 95% CI: 0.73-0.92). The rates of 30-day/1-year mortality and recurrent MI showed significantly decreasing trends (Ptrend < 0.001). The rates of first-time admission for HF were borderline significant (Ptrend = 0.045). CONCLUSION: From 2000 to 2017, we observed a decreasing risk of recurrent MI, first-time admission for HF, and all-cause mortality in patients with a first-time MI. In the same period, we observed a high rate of guideline-recommended pharmacological treatment after first-time MI as well as increasing rate of early revascularization in Denmark. TRANSLATIONAL PERSPECTIVES: The results from the current study portrait the risk of all-cause mortality, recurrent MI, and first-time admission for HF in a real-life setting with a very high utilization of early revascularization and guideline-recommended pharmacological therapy. We observed a temporal trend of improved survival, reduced risk of recurrent MI, as well as reduced risk of first-time admission for HF after first-time MI from 2000 through 2017. We observed an increase in the overall use of revascularization, as well as early revascularization and use of guideline-recommended pharmacotherapy. Our study reveals important results from real-life, nationwide data, showing a reduced risk of cardiovascular outcomes after first-time MI during the past 20 years. Current guidelines are based on results from clinical trials. Our real-life results add additionally important knowledge on patients' prognosis after first-time MI and underline the importance of treating MI according to guideline recommendations.

A Wnt11 and Dishevelled signaling pathway acts prior to injury to control wound polarization for the onset of planarian regeneration.

Regeneration is initiated by wounding, but it is unclear how injury-induced signals precisely convey the identity of the tissues requiring replacement. In the planarian Schmidtea mediterranea, the first event in head regeneration is the asymmetric activation of the Wnt inhibitor notum in longitudinal body-wall muscle cells, preferentially at anterior-facing versus posterior-facing wound sites. However, the mechanism driving this early symmetry-breaking event is unknown. We identify a noncanonical Wnt11 and Dishevelled pathway regulating notum polarization, which opposes injury-induced notum-activating Wnt/ß-catenin signals and regulates muscle orientation. Using expression analysis and experiments to define a critical time of action, we demonstrate that Wnt11 and Dishevelled signals act prior to injury and in a growth-dependent manner to orient the polarization of notum induced by wounding. In turn, injury-induced notum dictates polarization used in the next round of regeneration. These results identify a self-reinforcing feedback system driving the polarization of blastema outgrowth and indicate that regeneration uses pre-existing tissue information to determine the outcome of wound-induced signals.

Enhanced recovery after surgery is feasible and safe in liver transplantation: a cohort study.

BACKGROUND: The principles of enhanced recovery after surgery (ERAS) are being applied to still more advanced procedures. Liver transplantation offers a unique opportunity for a multimodal approach including donor care as well. Our objective was to determine if ERAS was applicable and safe in orthotopic liver transplantation (OLT). METHODS: A national single centre retrospective study showing the implementation of ERAS from 2013 to 2019 with the proceeding 2 years serving as baseline. The primary endpoints were mortality, length of stay (LOS) in the ward and intensive care unit stay. Secondary endpoints were complications estimated by Dindo-Clavien classification, comprehensive complication index (CCI®) and re-admissions. RESULTS: A total of 334 patients were included. LOS was significantly reduced from a median of 22.5 days at introduction to 14 days at 2019. Cold ischaemia time was reduced from a mean of 10.7 to 6.0 h and the use of blood products (erythrocytes, plasma and thrombocytes) from a median of 28 to 6 units. Complications were reduced in severity. Mortality and readmission rates were not affected. CONCLUSION: ERAS principles are safe and recommended in patients undergoing OLT resulting in reduced severity of complications and LOS without affecting re-admissions or mortality.

Photon-Assisted Tunneling of High-Order Multiple Andreev Reflections in Epitaxial Nanowire Josephson Junctions.

Semiconductor/superconductor hybrids exhibit a range of phenomena that can be exploited for the study of novel physics and the development of new technologies. Understanding the origin of the energy spectrum of such hybrids is therefore a crucial goal. Here, we study Josephson junctions defined by shadow epitaxy on InAsSb/Al nanowires. The devices exhibit gate-tunable supercurrents at low temperatures and multiple Andreev reflections (MARs) at finite voltage bias. Under microwave irradiation, photon-assisted tunneling (PAT) of MARs produces characteristic oscillating sidebands at quantized energies, which depend on MAR order, n, in agreement with a recently suggested modification of the classical Tien-Gordon equation. The scaling of the quantized energy spacings with microwave frequency provides independent confirmation of the effective charge, ne, transferred by the nth-order tunneling process. The measurements suggest PAT as a powerful method for assigning the origin of low-energy spectral features in hybrid Josephson devices.