Anatomical Techniques Research Articles

Comparative leaf anatomy in Ptilochaetoids clade (Malpighiaceae): A taxonomic and phylogenetic approach

In molecular phylogeny of Malpighiaceae, the Ptilochaetoide clade is composed of Dinemagonum, Dinemandra, Lasiocarpus and Ptilochaeta, found in the sub-desert and desert regions of South and Central America. The taxonomic relationship between the genera of the group is little discussed and phylogenetic studies point out to the need for an evolutionary approach using morphoanatomical characters. Thus, based on the recurrent contribution of leaf anatomy to taxonomic studies in Malpighiaceae, we characterized the leaf anatomy of seven species of the Ptilochaetoide clade and listed relevant anatomical patterns for their circumscription. For this, we used standard anatomical techniques and the anatomical data were discussed phylogenetically. The anatomical data such as: petiole/midrib contour, petiole/midrib vascular system conformation, presence/absence of trichomes and mesophyll organization were useful for the elaboration of the identification key. Character states: Plane-convex midrib contour, isobilateral mesophyll and absence of trichomes were considered informative for the subclade composed by Dinemandra and Dinemagonum, while in the other genera, no relevant morphotypes were recognized. The absence of accessory bundles, presence of druses and sheath extension are common features in the clade and contribute to the group description. These findings reaffirm the effectiveness of leaf anatomy in taxonomic and phylogenetic studies in Malpighiaceae.

Distinct neuron phenotypes may serve object feature sensing in the electrosensory lobe of Gymnotus omarorum.

Early sensory relay circuits in the vertebrate medulla often adopt a cerebellum-like organization specialized for comparing primary afferent inputs with central expectations. These circuits usually have a dual output, carried by center ON and center OFF neurons responding in opposite ways to the same stimulus at the center of their receptive fields. Here, we show in the electrosensory lateral line lobe of Gymnotiform weakly electric fish that basilar pyramidal neurons, representing 'ON' cells, and non-basilar pyramidal neurons, representing 'OFF' cells, have different intrinsic electrophysiological properties. We used classical anatomical techniques and electrophysiological in vitro recordings to compare these neurons. Basilar neurons are silent at rest, have a high threshold to intracellular stimulation, delayed responses to steady-state depolarization and low pass responsiveness to membrane voltage variations. They respond to low-intensity depolarizing stimuli with large, isolated spikes. As stimulus intensity increases, the spikes are followed by a depolarizing after-potential from which phase-locked spikes often arise. Non-basilar neurons show a pacemaker-like spiking activity, smoothly modulated in frequency by slow variations of stimulus intensity. Spike-frequency adaptation provides a memory of their recent firing, facilitating non-basilar response to stimulus transients. Considering anatomical and functional dimensions, we conclude that basilar and non-basilar pyramidal neurons are clear-cut, different anatomo-functional phenotypes. We propose that, in addition to their role in contrast processing, basilar pyramidal neurons encode sustained global stimuli such as those elicited by large or distant objects while non-basilar pyramidal neurons respond to transient stimuli due to movement of objects with a textured surface.

Position paper of the EACVI and EANM on artificial intelligence applications in multimodality cardiovascular imaging using SPECT/CT, PET/CT, and cardiac CT

In daily clinical practice, clinicians integrate available data to ascertain the diagnostic and prognostic probability of a disease or clinical outcome for their patients. For patients with suspected or known cardiovascular disease, several anatomical and functional imaging techniques are commonly performed to aid this endeavor, including coronary computed tomography angiography (CCTA) and nuclear cardiology imaging. Continuous improvement in positron emission tomography (PET), single-photon emission computed tomography (SPECT), and CT hardware and software has resulted in improved diagnostic performance and wide implementation of these imaging techniques in daily clinical practice. However, the human ability to interpret, quantify, and integrate these data sets is limited. The identification of novel markers and application of machine learning (ML) algorithms, including deep learning (DL) to cardiovascular imaging techniques will further improve diagnosis and prognostication for patients with cardiovascular diseases. The goal of this position paper of the European Association of Nuclear Medicine (EANM) and the European Association of Cardiovascular Imaging (EACVI) is to provide an overview of the general concepts behind modern machine learning-based artificial intelligence, highlights currently prefered methods, practices, and computational models, and proposes new strategies to support the clinical application of ML in the field of cardiovascular imaging using nuclear cardiology (hybrid) and CT techniques.

Functionalized Strategies and Mechanisms of the Emerging Mesh for Abdominal Wall Repair and Regeneration.

Meshes have been the overwhelmingly popular choice for the repair of abdominal wall defects to retrieve the bodily integrity of musculofascial layer. Broadly, they are classified into synthetic, biological and composite mesh based on their mechanical and biocompatible features. With the development of anatomical repair techniques and the increasing requirements of constructive remodeling, however, none of these options satisfactorily manages the conditional repair. In both preclinical and clinical studies, materials/agents equipped with distinct functions have been characterized and applied to improve mesh-aided repair, with the importance of mesh functionalization being highlighted. However, limited information exists on systemic comparisons of the underlying mechanisms with respect to functionalized strategies, which are fundamental throughout repair and regeneration. Herein, we address this topic and summarize the current literature by subdividing common functions of the mesh into biomechanics-matched, macrophage-mediated, integration-enhanced, anti-infective and antiadhesive characteristics for a comprehensive overview. In particular, we elaborate their effects separately with respect to host response and integration and discuss their respective advances, challenges and future directions toward a clinical alternative. From the vastly different approaches, we provide insight into the mechanisms involved and offer suggestions for personalized modifications of these emerging meshes.

The best of both worlds: Apomixis and sexuality co‐occur in species of Microlicia, Melastomataceae

AbstractApomixis, the asexual formation of embryos and seeds, occurs in approximately 18% of angiosperm families. Melastomataceae exhibits a remarkable number of apomictic species, distributed among different tribes. This mode of reproduction has been elucidated in Miconieae, but remains unclarified for other groups, such as Microlicieae. Although apomixis has been previously described for Microlicieae species, the cytological basis for this phenomenon is entirely unknown in this group. Thus, populations of Microlicia fasciculata and M. polystemma were used in order to (a) investigate the presence of autonomous apomixis; (b) verify if this mode of reproduction leads to polyembryony; and (c) investigate whether apomixis may occur in parallel with the sexual process. We tested these species for autonomous fruit set and polyembryony, and pollen viability, and analyzed pollen tube growth. Anatomical techniques were used to elucidate the micro‐ and megasporogenesis and gametogenesis. The species showed autonomous fruit and seed formation and exhibited polyembryony. Apospory and adventitious embryony were the developmental mechanisms of apomixis in M. fasciculata and M. polystemma, respectively. Both species exhibited low pollen viability. However, some viable pollen, reduced embryo sac formation, natural pollination and pollen tube growth enable sexual reproduction and characterize these species as facultative apomicts. The independence of pollinators for fruit set, uniparental reproduction and the possibility of sexual reproduction, confer reproductive assurance and flexibility, bringing together advantages of sexual and asexual reproduction. In this sense, apomixis may have played an important role in the evolution and diversification of Microlicia, a widely distributed genus in the Brazilian Cerrado.

Acromioclavicular Reconstruction Using Semitendinosus Tendon Autograft: A Technical Note and Case Report

Background: Although there are several surgical options for the treatment of acromioclavicular joint (ACJ) dislocation, there is no definite gold standard. Anatomical reconstruction techniques are becoming more popular due to the new understandings of the anatomy and biomechanics of the ACJ. Case Report: A 40-year-old male with left ACJ dislocation (Type 3 Rockwood classification) underwent anatomical reconstruction with a semitendinosus tendon graft harvested from the left knee. Conclusion: Anatomical reconstruction of ACJ by autograft is an effective treatment option.

The Posterior Cruciate Ligament: Anatomy, Biomechanics, and Double-Bundle Reconstruction

The posterior cruciate ligament (PCL) is the largest intra-articular ligament in the knee and is the primary stabilizer to posterior tibial translation. Historically, the PCL’s functional dynamics and appropriate management after injury have been controversial. However, recent biomechanical and anatomic studies have elucidated a better understanding of PCL function, which has led to development of more anatomic reconstruction techniques. The larger anterolateral bundle and the smaller posteromedial bundle of the PCL exhibit a codominant relationship and have a wide femoral attachment footprint. For these reasons, the native kinematics of the knee is better restored with a double-bundle PCL reconstruction (DB-PCLR) technique than with a single-bundle PCL reconstruction (SB-PCLR). Likewise, clinical studies have demonstrated excellent outcomes for DB-PCLR compared to SB-PCLR, with decreased posterior knee laxity on stress radiography and improved International Knee Documentation Committee scores. This review will provide a detailed overview of the clinically relevant anatomy, biomechanics, injury evaluation, and treatment options, with an emphasis on arthroscopic DB-PCLR.

Morphology, structure, and histochemistry of the inflorescences, fruit, and seed of the Ramón nut, Brosimum alicastrum Sw. subsp. alicastrum CC Berg (Moraceae)

Brosimum alicastrum Sw, known in Mexico as the Ramon nut, is a sustainable resource in the economy of Yucatan, Mexico; the pulp and seed are edible, and the latter is very nutritious when consumed whole or ground into corn or wheat flour to make tortillas and bread. Because the inflorescences are an essential source of Moraceae taxonomic traits, the histochemistry of the floral parts, fruit, and seed of B. alicastrum was studied to establish their structural characteristics and chemical nature. Different developmental stages of the structures were studied with anatomical and histochemical techniques and scanning electron microscopy. The species presented three achlamydeous floral morphs: (a) uniflorous, unisexual pistillate inflorescence, with the ovary embedded in the receptacle, and exposing a style with bifurcate stigma; (b) unisexual staminate inflorescence with flowers with one stamen, a straight and thick filament, a bilocular peltate anther, with fused theca and circumscissile dehiscence, characteristics that define it as Brosimum alicastrum Sw. subsp. alicastrum CC Berg; and (c) bisexual inflorescence with staminate flowers and a pistillate flower with an atrophied ovule. The fleshy and sweet pulp is derived from the receptacle containing glycoproteins and idioblasts. The endocarp, which derives from the ovary wall, has a coriaceous consistency, so the fruit is classified as a pome. Thick and unequal fleshy cotyledons with laticifers, proteinoplasts, amyloplasts, and idioblasts; endosperm is absent from the mature seed; a thin and lignified seed coat surrounds them. The nutritional characteristics of the fruit and seed were corroborated with positive reactions of histochemical techniques.

Satisfactory clinical outcomes using a novel arthroscopic technique for fixation of tibial spine avulsion fractures: technical note

This research aims to present a novel arthroscopic fixation technique that uses a double-row suture anchor for tibial spine avulsion and to evaluate its short-term clinical outcomes. The surgical technique is described and a retrospective case series is presented. Patients who presented with tibial spine avulsion type III and IV fractures according to the Meyers and McKeever classification and received the same surgical treatment from 2013 to 2018 in two specialised hospitals in Medellín City were included. All interventions were performed by an experienced surgeon. To determine outcomes during clinical follow-up, the Lysholm score and objective and subjective International Knee Documentation Committee scores were obtained before and at least 12 months after surgery. A total of 24 patients were followed, with a mean age of 31 years; 12 patients were female. The median time between trauma and surgical fixation was 12 days (IQR=7–23), with a median follow-up period of 13.5 months (IQR=9.5–31.5). When comparing patients’ state initially and during the postoperative period, statistically significant differences were found in all the scores analysed (p<0.05). Likewise, there were no complications and no reinterventions performed during follow-up, and all patients were satisfied with the outcomes of the procedure. Fixation of tibial spine avulsion fractures using the double-row suture anchor technique results in improvement in patients’ function, pain and activity level. The main conclusion is that the procedure is an anatomical technique that requires minimal access and leads to satisfactory clinical evolution of patients.Level of evidence: Level V, case series.

Large-Diameter Anterior Cruciate Ligament Reconstruction Technique With 8-Strand Semitendinosus and Gracilis Graft

Anterior cruciate ligament (ACL) reconstruction using a single 4-strand semitendinosus graft is a popular technique; unfortunately, the size (diameter) of the graft varies between 7 and 9 mm in many cases. The literature reveals that smaller diameter of the graft determines poorer Knee injury and Osteoarthritis Outcome Score sport/recreation functional scores and leads to revision surgery. Our Technical Note describes a method of preparing >10-mm size hamstring autografts in all cases while increasing the strength of fixation and covering as much of the anatomical ACL attachment footprint area as possible. We report an anatomic reconstruction technique of ACL with 8-strand semitendinosus and gracilis grafts fixed with 2 suspensory fixation systems—PULLUP (SBM, Lourdes, France). Combined with a complete tibial tunnel outside-in approach, this technique allows a quick and easy ACL reconstruction with a large diameter of the graft and increased stability of the fixation.

A new technique for determining the rotational alignment of the tibial component during total knee arthroplasty

BackgroundWe evaluated the effectiveness of our new technique “Range of motion-anatomical (ROM-A) technique” which is the combination of the self-positioning technique “Range of motion (ROM) technique” and the anatomical landmarks technique in determining the tibial component (TC) rotation alignment in total knee arthroplasty (TKA) using a navigation system. MethodsThis retrospective study included 103 knees who underwent TKA. The ROM-A technique was consisted of two steps. First, the TC was set and marked by the ROM technique in knee extension. Second, the TC was set according to the marking in the knee flexion and the component rotational angle relative to the anatomical tibial anteroposterior (AP) axis was adjusted between 0° and 10° external rotation using the navigation system. The rotational angle of TC relative to the anatomical AP axis was measured using postoperative computed tomography. Moreover, the hypothetical rotational angle of the TC in the ROM technique was calculated only from the intraoperative difference between the two techniques. ResultsThe actual rotational angle by the ROM-A technique was externally rotated 3.0°, and the rotational outlier occurred in 3.0%. A significant difference in outlier rate was observed between the two techniques (p = 0.03). The hypothetical rotational angle of TC determined by the ROM technique (the first step only in the ROM-A technique) was externally rotated 4.6° and the TC rotational outlier (difference to AP axis: >10°) occurred in 11.7%. ConclusionUsing the ROM-A technique, the TC was finally fixed in almost all targeted rotational positions, and this technique could reduce the anatomical rotational outlier compared with the ROM technique.

Hybrid Ankle Reconstruction of Lateral Ligaments

Open anatomic reconstruction of the lateral ligament (AntiRoLL) of the ankle with a gracilis Y graft and the inside-out technique are commonly used and have evolved to minimally invasive surgery, including arthroscopic AntiRoLL (A-AntiRoLL) and percutaneous AntiRoLL procedures. A-AntiRoLL allows assessment and treatment of intra-articular pathologies of the ankle concurrently with stabilization. However, the A-AntiRoLL technique is technically demanding, especially in the process of calcaneofibular ligament reconstruction under subtalar arthroscopy. In contrast, the percutaneous AntiRoLL procedure is a simple concept that does not require the skill of an experienced arthroscopist but requires an extra skin incision to assess and treat intra-articular pathologies of the ankle. This study describes the application of a minimally invasive anatomic reconstruction technique—hybrid AntiRoLL—for chronic instability of the ankle that does not require advanced arthroscopic technique to assess and treat intra-articular pathology simultaneously.

Arthroscopically assisted transmalleolar internal fixation of a lateral osteochondral lesion of the talus

Osteochondral lesions (OCL) of the talus can be caused by isolated or recurrent traumatic events. The established surgical treatment techniques are predominantly based on defect coverage by stimulation of fibrous cartilage or transplantation of osteochondral tissue or chondrocytes. An alternative is the preservation of an intact autochthonous hyaline cartilage surface with reconstruction of the subchondral lamella and the natural joint congruence. This anatomical technique can be used for selected acute and chronic OCL and can frequently be carried out arthroscopically. This article presents the indications, contraindications, advantages and targets as well as the planning and execution of arthroscopically assisted transmalleolar internal fixation of a lateral OCL of the talus.

Neural interconnection between acupoint “Chéngshān” (承山BL57) and sciatic nerve in the rat: 大鼠“承山”穴和坐骨神经之间的神经解剖学联系

ObjectiveThe aim of this study is to assess the neural interconnection between the acupoint “Chéngshān (承山BL57)” and sciatic nerve from the peripheral nervous system (PNS) to the central nervous system (CNS). MethodsSD rats were systematically examined from the hip to the hind limb along the route of sciatic nerve with regional anatomical technique, and further traced from the BL57 and the trunk of sciatic nerve by the neural tracing technique with cholera toxin subunit B (CTB) and CTB conjugated Alexa Fluor 488 and 594 (CTB-AF488/594). ResultsAfter regional anatomy, it was found that the sciatic nerve ran down from the hip to the hind limb and sequentially sent out the tibial and sural branches respectively to the deep and superficial layers of BL57. The CTB labeling associated with both BL57 and sciatic nerve distributed in the same spinal segments and definite regions, including the sensory neurons in lumber 3 (L3) -lumber 6 (L6) dorsal root ganglia (DRGs), transganglionic axons mainly in the L3-L6 spinal dorsal horn, Clarke's nucleus, and gracile nucleus, as well as motor neurons mainly in the L3-L6 spinal ventral horn. However, the amount of neural labeling was significantly less in the cases of BL57 than that of sciatic nerve. ConclusionsThese results indicate that there is distinct sensory and motor interconnection between the BL57 and the sciatic nerve, which may potentially serve for the active role of the BL57 playing in meliorating the disorders of sciatic nerve.

Magnetoencephalography in the Detection and Characterization of Brain Abnormalities Associated with Traumatic Brain Injury: A Comprehensive Review.

Magnetoencephalography (MEG) is a functional brain imaging technique with high temporal resolution compared with techniques that rely on metabolic coupling. MEG has an important role in traumatic brain injury (TBI) research, especially in mild TBI, which may not have detectable features in conventional, anatomical imaging techniques. This review addresses the original research articles to date that have reported on the use of MEG in TBI. Specifically, the included studies have demonstrated the utility of MEG in the detection of TBI, characterization of brain connectivity abnormalities associated with TBI, correlation of brain signals with post-concussive symptoms, differentiation of TBI from post-traumatic stress disorder, and monitoring the response to TBI treatments. Although presently the utility of MEG is mostly limited to research in TBI, a clinical role for MEG in TBI may become evident with further investigation.

Anatomic Double-Bundle Transtibial Anterior Cruciate Ligament Reconstruction

Double-bundle anterior cruciate ligament (ACL) reconstruction (DBACLR) is a reasonable transition from single-bundle ACL reconstruction to obtain better clinical outcomes, and most authors believe that it can only be performed through a medial portal. However, in our clinical practice, we have found that anatomic DBACLR can be performed easily and exactly through transtibial tunnels just by positioning the tibial tunnels appropriately. Thus, we would like to introduce this anatomic double-bundle transtibial ACL reconstruction technique, in which the most critical step is to create a shallow tibial tunnel for the anteromedial bundle with a proximal projection to the anatomic location of the corresponding femoral tunnel. We believe this Technical Note will give an interesting view of anatomic DBACLR.

Perfecting temporary pacemakers in a developing country

ABSTRACT Introduction Transvenous pacemakers are used to temporarily pace heart in emergent situations. This study was conducted to analyze the current success rate of temporary pacemaker insertion in our institution and discover causes for failure to improve the technique. Methodology A retrospective cohort study was conducted of 263 patients from 2006 to 2016 who underwent TPM insertion at Aga Khan University Hospital, Karachi. Results The success rate for the procedure was 97.7%, with one mortality caused by the pacemaker. No significant risk factor was found for the failure of TPM. Conclusion There was no significant effect of anatomical site or technique on the failure of TPM insertion. However, with better training and higher experience of the residents, the complications and rate of failures can be reduced.

Radiomic signatures to predict survival in patients with advanced hepatocellular carcinoma (HCC) treated with sorafenib +/- doxorubicin: Correlative science from CALGB 80802 (Alliance).

343 Background: Alliance/CALGB 80802, a randomized phase III trial, evaluated sorafenib plus doxorubicin vs. doxorubicin in pts with HCC and showed no improvement in median overall survival (OS) (HR[95CI] 1.05[0.83-1.31]) or PFS (HR[95CI] 0.93[0.75-1.16]). In HCC surrogacy of tumor response with OS remains controversial, in part due to varying criteria used for response evaluation (e.g., RECIST1.1 and mRECIST). We evaluated the performance of several models to predict OS using pretreatment clinical and radiomic variables. Methods: In CALBG 80802, we segmented all measurable tumor lesions on sequential CT scans. A lesion’s imaging phenotype was deciphered with 23 uncorrelated quantitative imaging features measured at baseline and week (wk) 10 (first follow-up). An OS landmark survival analysis was conducted at wk 10. Patients were randomly assigned (3:1) to training (n = 92) and validation (n = 37) sets. In a training set, 6 random forest predictive models (6 signatures) used features that best predicted OS using 3 sets of variables: radiomics only (n = 23), clinical only (n = 9), radiomics and clinical (n = 32). Two time points (baseline only or baseline + wk 10) were assessed. Each signature's output was an individualized prediction and a continuous value ranging from 0 to 1 (from most to least favorable predicted OS). The primary endpoint was to compare these models' performance to predict OS using error rate (Harrell's concordance-index) in the validation set. Results: Of the 6 training signatures evaluated, the one achieving the highest performance in the validation set was an 8-feature signature combining radiomics and clinical variables measured at two time points (baseline + wk 10) with an error rate of 35.6%. The variables [rank of importance] (table) selected by the signature included baseline clinical features (albumin[1], AFP[2], Child-Pugh[4]), baseline radiomics features (component 17[3], component 1[5], component 9[7], tumor volume[8]) and wk 10 radiomics features (delta tumor volume[6]). Variable delta tumor volume [6] used a more enhanced estimation of tumor burden at baseline and a delta tumor volumetric measurement; compared to RECIST1.1 measurement of percentage change in unidimensional measurement of a subset of target lesions. The four quartiles of the signature were significantly associated with OS (Log-Rank, P &lt; 0.0001). Conclusions: The selected combined radiomic and clinical composite signature provided the best prediction for OS in the 80802 study patients’ population. It is a suggested way forward to go beyond single anatomic measurement techniques such as RECIST or mRECIST. [Table: see text]

Anatomic Posterolateral Corner Reconstruction Using Semitendinosus and Gracilis Autografts: Surgical Technique

An anatomically based posterolateral corner (PLC) reconstruction has emerged as a viable and clinically effective surgical technique for midsubstance ligamentous injuries in both the acute and chronic settings. There are several surgical techniques for PLC reconstruction; however, the classic anatomic reconstruction technique (LaPrade technique) is now considered the gold standard and was originally described using an Achilles tendon allograft. In this article, we describe a modified LaPrade autograft technique, in which the same tunnel position, graft passage, and fixation are used to reproduce the 3 primary stabilizers of the PLC. Instead of allografts, hamstring autografts are used while tunnel diameters and fixation devices are adapted to them. With the use of autograft tendons, difficulties related to graft length or asymmetry are encountered. We consider this technique a good alternative for an anatomically based PLC reconstruction, especially given the lower availability and higher cost of allograft tissues in several countries.

Modified Technique for Combined Reconstruction of Anterior Cruciate Ligament and Anterolateral Ligament

During the past few decades, surgical techniques for anterior cruciate ligament (ACL) reconstruction have been developing significantly. To date, studies have shown that after ACL reconstruction, rotational stability has a greater impact on the patient's satisfaction, functional scores, and return to sports than translational stability. Although challenged by many authors in the literature, biomechanical studies on the anterolateral ligament (ALL) of the knee and clinical studies regarding ALL reconstruction have been revealing promising results. Thus, the potentially significant role of the ALL in biomechanical load sharing and improving rotational control of the knee has led to the development of various reconstruction techniques whose goal is to achieve simplicity and yield the best results possible. Guided by this idea, we have developed a modified ACL-ALL reconstruction surgical technique. In this article, our simple, bone-saving, anatomic technique to reconstruct both the ACL and ALL using hamstring tendon autograft is described.