Case of Ectopic Variceal Bleed Managed With Percutaneous Transhepatic Portal Vein Recanalization.

A variety of complications and associated clinical presentations may be seen in patients with cirrhotic and non-cirrhotic portal hypertension. We present one such case of Upper GI hemorrhage from ectopic duodenal varices in a case of pre-hepatic portal hypertension due to Extrahepatic Portal Venous Obstruction (EHPVO). The case was managed successfully with endovascular Portal Vein Recanalization (PVR) and metallic stent deployment. With adequate technical success, improved symptoms, and laboratory parameters, the patient was discharged on long-term anticoagulation and interval follow-up.

C-H Bond Activation by an Antimony(V) Oxo Intermediate Accessed through Electrochemical Oxidation of Antimony(III) Tetrakis(thiocyano)corrole.

A new class of antimony(III) corroles has been described. The photophysical properties of these newly synthesized tetrakis(thiocyano)corrolatoantimony(III) derivatives having four SCN groups on the bipyrrole unit of corrole are drastically altered compared to their ß-unsubstituted corrolatoantimony(III) analogues. The UV-vis and emission spectra of tetrakis(thiocyano)corrolatoantimony(III) derivatives are significantly red-shifted (roughly 30-40 nm) in comparison with their ß-unsubstituted corrolatoantimony(III) derivatives. The Q bands are significantly strengthened. The intensity of the most prominent Q band is roughly 70% that of the Soret band and absorbs strongly at the far-red region, i.e., at 700-720 nm. These molecules emit light in the near-infrared region (700-900 nm). Tetrakis(thiocyano)corrolatoantimony(III) undergoes electrochemical anodic oxidation to form SbV═O species, which facilitates electrocatalytic oxygen evolution reaction (OER) and the activation of benzylic C-H to produce benzoic acid selectively. Under optimized conditions, SbIII-corrole@NF (NF = nickel foam) required an overpotential of 380 mV to reach a 50 mA cm-2 current density, comparable with those of other transition-metal-based complexes. On the other hand, replacing the anodic OER with benzyl alcohol oxidation lowered the required potential by 150 mV (at 300 mA cm-2) to improve the energy efficiency of the electrochemical process.

Free-Base Corrole Anion.

Free-base corroles have long been known to be acidic, readily undergoing deprotonation by mild bases and in polar solvents. The conjugate base, however, has not been structurally characterized until now. Presented here is a first crystal structure of a free-base corrole anion, derived from tris(p-cyanophenyl)corrole, as the tetrabuylammonium salt. The low-temperature (100 K) structure reveals localized hydrogens on a pair of opposite pyrrole nitrogens. DFT calculations identify such a structure as the global minimum but also point to two cis tautomers only 4-7 kcal/mol above the ground state. In terms of free energy, however, the cis tautomers are above or essentially flush with the trans-to-cis barrier so the cis tautomers are unlikely to exist or be observed as true intermediates. Thus, the hydrogen bond within each dipyrrin unit on either side of the molecular pseudo-C2 axis through C10 (i.e., between pyrrole rings A and B or between C and D) qualifies as or closely approaches a low-barrier hydrogen bond. Proton migration across the pseudo-C2 axis entails much higher activation energies >20 kcal/mol, reflecting the relative rigidity of the molecule along the C1-C19 pyrrole-pyrrole linkage.

Indian National Association for Study of the Liver (INASL) Guidance Paper on Nomenclature, Diagnosis and Treatment of Nonalcoholic Fatty Liver Disease (NAFLD).

Nonalcoholic fatty liver disease (NAFLD) is a major cause of chronic liver disease globally and in India. The already high burden of NAFLD in India is expected to further increase in the future in parallel with the ongoing epidemics of obesity and type 2 diabetes mellitus. Given the high prevalence of NAFLD in the community, it is crucial to identify those at risk of progressive liver disease to streamline referral and guide proper management. Existing guidelines on NAFLD by various international societies fail to capture the entire landscape of NAFLD in India and are often difficult to incorporate in clinical practice due to fundamental differences in sociocultural aspects and health infrastructure available in India. A lot of progress has been made in the field of NAFLD in the 7 years since the initial position paper by the Indian National Association for the Study of Liver on NAFLD in 2015. Further, the ongoing debate on the nomenclature of NAFLD is creating undue confusion among clinical practitioners. The ensuing comprehensive review provides consensus-based, guidance statements on the nomenclature, diagnosis, and treatment of NAFLD that are practically implementable in the Indian setting.

Comparison of Clinical, Biochemical, and Histopathologic Profiles between NAFLD in Asian-Indians and United States Adults.

Background and aims: Nonalcoholic fatty liver disease (NAFLD) is very common in both Asian and Western countries. Geographic variation leads to differences in epidemiological and demographic characters of NAFLD patients. Studies conducted upon different ethnic groups in the United States (US) show a higher prevalence of NAFLD in Hispanics and African-Americans. There is however, a paucity of studies involving Asians. It has been observed that Asian-Indian NAFLD patients have unique characteristics compared to their counterparts in the West. This study is the first attempt at comparing the characteristics of Asian-Indian and US NAFLD patients. Materials and Methods: A retrospective analysis of clinical, biochemical, and histological data was performed for 633 Asian-Indian NAFLD patients and 451 US NAFLD patients. Clinical parameters [age, gender, body mass index (BMI), diabetes, hypertension, etc.], biochemical tests (liver function tests, lipid profile, and fasting blood sugar), hepatic ultrasound and hepatic histology were compared between the two cohorts. Results: Eighty-two percent of US NAFLD patients were more than 40 years of age compared to 51.3% of Asian-Indian patients (p <0.01). US (male 56.3%) and Asian-Indian (male 81.7%) (p <0.01) patients differed from each other as regards gender prevalence. Rates of obesity were greater in the US patients compared to Asian-Indians (BMI 32.6 ± 5.3 kg/m2 vs 26.2 ± 3.4 kg/m2). There was a higher prevalence of both diabetes and hypertension (diabetes 42.1% vs 33%, and hypertension 56.8% vs 29.7%, p ≤0.01) in US patients. ALT levels were also significantly higher in US NAFLD patients compared to Asian-Indians (ALT 82.78 ± 71.30 vs 53.66 ± 37, p ≤0.01). A higher proportion of US patients were found to have the more advanced liver disease at the time of diagnosis compared to Asian-Indians (Stage 3 fibrosis 10.42% vs 0%, and Stage 4 fibrosis 2.66% vs 0%, p <0.01). Conclusion: Asian-Indian and US NAFLD patients differ significantly on several parameters. Further studies need to be carried out to understand the mechanistic basis of these differences better. How to cite this article: Singh SP, Panigrahi MK, Patel A, et al. Comparison of Clinical, Biochemical, and Histopathologic Profiles between NAFLD in Asian-Indians and United States Adults. Euroasian J Hepato-Gastroenterol 2022;12(Suppl 1):S15-S18.

Synthesis, Characterization, and the N Atom Transfer Reactivity of a Nitridochromium(V) Complex Stabilized by a Corrolato Ligand.

Metal complexes bearing nitrido ligands (M≡N) are at the forefront of current scientific research due to their resemblances with the metal complexes involved in the nitrogen fixation reactions. An oxo(corrolato)chromium(V) complex was used as a precursor complex for the facile synthesis of a new nitrido(corrolato)chromium(V) complex. The nitrido(corrolato)chromium(V) complex was characterized by various spectroscopic techniques. Density functional theory (DFT) calculations were performed on the nitrido(corrolato)chromium(V) complex to assign the vibrational and electronic transitions of this complex. The chromium-nitrogen (nitrido) bond distance obtained in the DFT-optimized structure is 1.530 Å and matches well with the earlier reported authentic Cr≡N bond distances obtained from the single-crystal X-ray diffraction data. This nitrido(corrolato)chromium(V) compound exhibited a sharp Soret band at 438 nm and a Q band at 608 nm. DFT calculations deliver that the origin of the bands at 438 and 608 nm is due to the intraligand charge transfer transitions. The nitrido(corrolato)chromium(V) complex showed one reversible oxidation and one reversible reduction couple at +0.53 and -0.06 V, respectively, vs the Ag/AgCl reference electrode. The simulation of the electron paramagnetic resonance data of the nitrido(corrolato)chromium(V) compound provided the following parameters: g iso = 1.987, A 53Cr = 26 G, and A 14N = 2.71 G. From all these analyses, we can conclude that the electronic configuration in the native state of nitrido(corrolato)chromium(V) can be best described as [(cor3-)CrV(N3-)]-. Reactions of nitrido(corrolato)chromium(V) with the chloro(porphyrinato)chromium(III) complex resulted in a complete intermetal N atom transfer reaction between chromium corrole and chromium porphyrin complexes. A second-order rate constant of 4.29 ± 0.10 M-1 s-1 was obtained for this reaction. It was also proposed that this reaction proceeds via a bimetallic µ-nitrido intermediate.

NIR-emissive, singlet-oxygen-sensitizing gold tetra(thiocyano)corroles.

Presented herein are two fully characterized gold tetrathiocyanocorroles representing a potentially significant new class of NIR-emissive 5d-metallocorroles. The four SCN groups on the bipyrrole unit of the corrole exert a powerful electron-withdrawing effect, upshifting both the oxidation and reduction potentials by roughly half a volt relative to their unsubstituted counterparts. That said, the upshift of the LUMO is somewhat higher than that of the HOMO so these complexes also exhibit a smaller HOMO-LUMO gap, as evinced in both electrochemical measurements and Q band energies (∼595 nm relative to ∼571 nm for their SCN-free counterparts). The new compounds exhibit NIR phosphorescence under ambient conditions with emission maxima around 900 nm (compared with 790 nm for simple Au triarylcorroles), phosphorescence quantum yields around 0.3%, phosphorescence lifetimes around 10 µs, and singlet oxygen sensitization with a quantum yield of around 50 ± 5% in solution, together signifying wide-ranging potential applications as triplet photosensitizers in oxygen sensing and photodynamic therapy.

Investigation of the Nature of Intermolecular Interactions in Tetra(thiocyanato)corrolato-Ag(III) Complexes: Agostic or Hydrogen Bonded?

Tetra(thiocyanato)corrolato-Ag(III) complexes presented here constitute a new class of metallo-corrole complexes. The spectroscopic properties of these complexes are quite unusual and interesting. For example, the absorption spectra of these ß-substituted corrolato-Ag(III) complexes are very different from those of the ß-unsubstituted corrolato-Ag(III) derivatives. Single-crystal XRD analysis of a representative tetra(thiocyanato)corrolato-Ag(III) derivative reveals C-H···Ag interactions. The C-H···Ag interactions are rarely demonstrated in the crystal lattice of a discrete coordination/organometallic compound. Optimization of the hydrogen positions of the crystal structure discloses the geometrical parameters of the said interaction as a Ag···H distance of 2.597 Å and ∠C-H···Ag of 109.62°. The natural bond orbital analysis provides information about the donor-acceptor orbitals involved in the interactions and their interaction energies. It was observed that the σC-H orbital overlaps with the vacant d-orbital of Ag with an interaction energy of 17.93 kJ/mol. The filled d-orbital of Ag overlaps with the σ*C-H orbital with an interaction energy of 4.79 kJ/mol. The highlights of this work are that the H···Ag distance is outside of the distance range for the typical agostic interaction but fitted with the weak H-bond distance. However, the ∠C-H···Ag angle is within the range of the agostic interaction. Both crystallographic data and electronic structure calculations reveal that these kinds of intermolecular interactions in square-planar d8 Ag(III) complexes are intermediate in nature. Thus, they cannot be categorically called either hydrogen bonding or agostic interaction.

Clinicopathological Profile and Outcome of a Large Cohort of Patients with Nonalcoholic Fatty Liver Disease from South Asia: Interim Results of the Indian Consortium on Nonalcoholic Fatty Liver Disease.

Background: Previous data from South Asia and India had shown that patients with nonalcoholic fatty liver disease (NAFLD) have mild liver disease severity. There are no data regarding long-term clinical outcomes in patients with NAFLD from South Asia. The aim of the study was to evaluate the clinicopathological profile, severity of NAFLD, and clinical outcomes in a large cohort of patients with NAFLD from South Asia. Methods: In an ongoing real-life study [Indian Consortium on nonalcoholic fatty liver disease (ICON-D)], interim data captured across 23 centers in India over 18 months was analyzed for clinicopathological profile, severity of NAFLD, and hepatic/extrahepatic events on follow-up. Results: Of 4313 patients (mean age 45 ± 12.2 years, males 52%), data on metabolic risk factors in 3553 (82.3%) patients revealed that 378 (10.6%) were lean, 575 (16.2%) overweight, 2584 (72.7%) obese; metabolic syndrome in 1518 (42.7%) and at least one metabolic risk factor in 3292 (92.6%) patients. Evidence of significant or advanced fibrosis assessed with [aspartate transaminase to platelet ratio index (APRI), n = 3196 (74%)], [fibrosis-4 (FIB-4), n = 3554 (82.4%)], [NAFLD fibrosis score (NFS), n = 1924 (44.6%)], [Fibroscan, n = 2475, (57.3%)], and histology [n = 267 (6.2%)] was present in 682 (21.3%), 676 (19%), 397 (20.6%), 715 (29%), and 41 (15.4%) patients, respectively; 246 (10%) patients on Fibroscan and 22 (8.2%) on histology had evidence of cirrhosis. On a mean follow-up 43.5 months, hepatic and extrahepatic events recorded in 1353 (31.3%) patients showed that patients with compensated cirrhosis [71 (5.2%)] had more hepatic [26 (36.7%)] and extrahepatic events [8 (11.3%)] in comparison with those without cirrhosis (P < 0.0001). Conclusion: Around one fifth of patients with NAFLD in South Asia have significant liver disease. Both hepatic and extrahepatic events on follow-up are observed more commonly in patients with nonalcoholic steatohepatitis-related compensated cirrhosis.

Metal Complexes of Singly, Doubly and Triply Linked Porphyrins and Corroles: An Insight into the Physicochemical Properties.

Metal complexes of multi-porphyrins and multi-corroles are unique systems that display a host of extremely interesting properties. Availability of free meso and ß positions allow formation of different types of directly linked bis-porphyrins giving rise to intriguing optical and electronic properties. While the fields of metalloporphyrin and corroles monomer have seen exponential growth in the last decades, the chemistry of metal complexes of bis-porphyrins and bis-corroles remain rather underexplored. Therefore, the impact of covalent linkages on the optical, electronic, (spectro)electrochemical, magnetic and electrocatalytic activities of metal complexes of bis-porphyrins and -corroles has been summarized in this review article. This article shows that despite the (still) somewhat difficult synthetic access to these molecules, their extremely exciting properties do make a strong case for pursuing research on these classes of compounds.

Large-Scale Green Synthesis of Porphyrins.

A new methodology for porphyrin synthesis has been developed. This is a simple two-step protocol. The first step involves the condensation of pyrrole and aldehyde in an H2O-MeOH mixture using HCl. The obtained precipitate from the first step was dissolved in reagent-grade dimethylformamide (DMF) and refluxed for 1.5 h, followed by stirring overnight in the air at room temperature. Subsequent purification through column chromatography or crystallization resulted in the formation of pure porphyrins. Advantageously, this methodology does not need any expensive chemicals such as 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ), chloranil, and so forth as an oxidizing agent. This reaction also does not require a large volume of dry chlorinated solvents. Contrary to the reported methodologies, which are mostly ineffective in the gram-scale production of porphyrins, the present method perfectly caters to the need for gram-scale production of porphyrins. In essence, the current methodology does not represent the synthesis having the highest yield in the literature. However, it represents the easiest and cheapest synthesis of porphyrin on a large scale to obtain a reproducible yield of 10-40% with high purity. In a few of the examples, even column chromatography is not necessary. A simple crystallization technique will be sufficient to generate the desired porphyrins in good yields.

An oxo(corrolato)chromium(V) complex selectively kills cancer cells by inducing DNA damage.

An oxo(corrolato)chromium(v) complex selectively kills leukemia cells. However, this complex did not induce cell death in primary non-cancer cells. It has been observed that oxo(corrolato)chromium(v) complex induced cell death is associated with DNA damage. Interestingly, the DNA in primary cells largely remained unaffected. DNA isolated from normal and cancerous cell lines also follows similar trends. A chemical reductant, DTT, was used to probe the mechanism of DNA damage. However, it does not show any additive effect on DNA damage.

Photocatalytic C-H Thiocyanation of Corroles: Development of Near-Infrared (NIR)-Emissive Dyes.

A new method of activating corrole macrocycles via an in situ generated SCN radical has been developed at very mild conditions at room temperature. This photoredox reaction resulted in the generation of tetrathiocyanatocorroles in good yields. The synthesis of tetrathiocyanatocorroles was never reported earlier. Single-crystal XRD analysis reveals that the insertion of four thiocyanate moieties at the four ß-pyrrolic positions has imparted significant distortion to the corrole macrocycle. The generated tetrathiocyanatocorroles are different from the parent corroles in many ways. The photophysical properties of the newly synthesized tetrathiocyanatocorroles are dramatically altered from the parent corroles. The absorption feature of these modified corrole derivatives (both position and intensity) bears a nice similarity with the chlorophyll-a macrocycle. Thus, these newly synthesized molecules can be considered as spectroscopic model systems for chlorophyll-a pigments. The observed absorption and emission spectra of these tetrathiocyanatocorroles certainly point out that these newly developed ligand scaffolds and their various metal complexes will have immense potential as pigments in solar cells and also as NIR-emissive dyes. The observed C-H···Au weak interactions in a representative Au(III)-corrole complex point out that these complexes are capable of activating the unfunctionalized C-H groups and thus will have potential implications in C-H activation reactions.

Synthesis, Characterization, and Application of Oxo-Molybdenum(V)-Corrolato Complexes in Epoxidation Reactions.

Sharpless et al. have described, while performing the molybdenum-catalyzed epoxidation reaction of olefins using alkyl hydroperoxides, that the molybdenum-oxo moiety is an active catalytic species. Thus, continuous efforts have been made to synthesize molybdenum-oxo complexes of different ligand environments. While plenty of such works on molybdenum porphyrins are reported in the literature, related molybdenum corroles are very less reported. The synthesis and characterization of two new oxo-molybdenum(V)-corrolato complexes are described herein. Both the complexes have been fully characterized by several spectroscopic techniques in conjunction with single-crystal X-ray diffraction analysis. The efficacy of the oxo-molybdenum(V)-corrolato complexes for the catalytic epoxidation reaction of olefins with the help of hydroperoxides has also been explored. The catalytic application of oxo-molybdenum(V)-corrolato complexes in the epoxidation reaction has not been reported earlier. A mechanism has been proposed to explain the experimental findings.

A new synthesis of porphyrins via a putative trans-manganese(iv)-dihydroxide intermediate.

A new method for the synthesis of meso-substituted porphyrins was developed. In this two-step methodology, the first step involves the condensation of pyrroles/dipyrromethanes with aldehydes in a water-methanol mixture under acidic conditions. The second step involves manganese induced cyclization followed by oxidation via PhIO/O2. This methodology has been useful for the synthesis of a wide range of trans-A2B2 porphyrins and also symmetric porphyrins in moderate to good yields. A detailed investigation of the manganese induced cyclization reaction has allowed us to characterize a Mn-porphyrinogen complex. A series of analytical and spectroscopic techniques and DFT calculations have led us to the conclusion that the putative intermediate species are trans-manganese(iv)-dihydroxide complexes. EPR and magnetic susceptibility measurements helped us to assign the oxidation state of the manganese complexes in their native state. The assumption of trans-manganese(iv)-dihydroxide as the true intermediate for this porphyrin synthesis has been authenticated via in situ UV-Vis experiments. This new methodology is certainly different from other previously reported methodologies in many aspects and most importantly these reactions can be easily performed on a gram scale for the synthesis of porphyrins.

Regioselective thiocyanation of corroles and the synthesis of gold nanoparticle-corrole assemblies.

Herein we demonstrate a synthetic protocol for the regioselective thiocyanation of corroles. To the best of our knowledge, thiocyanato appended corrole has never been reported earlier. The resulting thiocyanato appended corrole turned out to be a good corrole based precursor for the facile synthesis of thiol protected gold nanoparticles (Au NPs). The ligand system acts as a good bidentate framework and passivates the gold surface. A strong electronic interaction between the corrole and the gold nanoparticles is manifested by their unique photo physical properties and it also confirms that the binding through ß-substitutions has a more pronounced effect even though the corrole rings are face-off to the gold surface.

Biopsy Proven Fibrosis in Non-Alcoholic Fatty Liver Disease: An Analysis of Risk Factors.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is emerging as an important cause of liver disease in India. NAFLD is characterized by hepatic steatosis in absence of a significant alcohol use or other known liver disease. Non-alcoholic steatohepatitis (NASH) is a progressive form of NAFLD which deserves particular attention because it is more prone for development of fibrosis. Liver biopsy is the gold standard for diagnosis of NASH by evaluating necroinflammatory activity and stages of fibrosis. The aim of the study was to analyze liver biopsy specimens and identify risk factors associated with fibrosis in patients of NAFLD in eastern coastal India. METHODS: A total of 216 subjects with fatty liver in ultrasonography (USG) were selected for needle biopsy. Those NAFLD cases showing fibrosis in biopsy were analyzed for risk factors association. RESULTS: Definite NASH was diagnosed in 50 (23.14%), borderline NASH in 66 (30.55%) and not NASH in 100 (46.39%) of cases. Those patients with fibrosis (22%) were taken as cases and those without fibrosis (78%) were taken as controls for risk factor analysis. Age > 40 [odds ratio (OR) 2.01 (1.09-4.04)], female gender [OR 2.74 (1.24-6.05)], body mass index (BMI) > 23 [OR 15.36 (4.59-51.37)] and moderate fatty change in USG [OR 1.89 (1.01-3.62)] were observed as risk factors for progression to fibrosis in NAFLD cases. CONCLUSION: Older age, females, obesity and moderate fatty liver on USG are risk factors for development of fibrosis in patients with NAFLD. Patients with these risk factors should be selected for liver biopsy and to be kept for close follow-up.

Metal coordination induced ring contraction of porphyrin derivatives.

A remarkable rearrangement of a diferrocenylporphyrin to give a silver(iii) corrole has been discovered. Compared to the previously reported porphyrin to corrole ring conversions (extremely rare and poor reaction yields), our methodology delivers near quantitative yield for this ring contraction.

Chromium Complexes with Oxido and Corrolato Ligands: Metal-Based Redox Processes versus Ligand Non-Innocence.

Metal- versus ligand-centered redox processes and the effects of substituents on the ligands on the spectroscopic properties of the metal complexes are at the heart of research on metal complexes with non-innocent ligands. This work presents three examples of chromium complexes that contain both oxido and corrolato ligands, with the substituents on the corrolato ligands being different in the three cases. Combined X-ray crystallographic, electrochemical, UV/Vis/NIR/EPR spectroelectrochemical, and EXAFS/XANES measurements, together with DFT calculations, have been used to probe the complexes in three different redox forms. This combined approach makes it possible to address questions related to chromium- versus corrolato-centered redox processes, and the accessibility (or not) of CrIV , CrV , and CrVI in these complexes, as well as their spin states. To the best of our knowledge, these are the first EXAFS/XANES investigations on Cr-corrolato complexes in different redox forms, and hence these data should set benchmarks for future investigations on such complexes by this method.

Biochemical Profile of Nonalcoholic Fatty Liver Disease Patients in Eastern India with Histopathological Correlation.

Aminotransferase assay is often used as a screening test as well as an endpoint for resolution of disease in nonalcoholic fatty liver disease (NAFLD). Aim of the study was to evaluate the relationship of transaminase level with metabolic variables and histology in NAFLD. Single center observational study was conducted in a gastroenterology clinic at Cuttack in coastal Odisha. Subjects were consecutive patients presenting with functional bowel disease and undergoing abdominal sonography. All participants were evaluated for the presence of metabolic syndrome (MS), insulin resistance, liver function test and lipid profile. Various parameters were compared between NAFLD subjects and controls. 53.5 % of NAFLD had normal serum transaminases, whereas 20.8 % of healthy controls had transaminitis. NAFLD patients had significantly higher BMI, fasting plasma glucose, serum transaminases, serum triglycerides, serum insulin and homeostatic model assessment (HOMA) IR than controls. NAFLD patients who had transaminitis had significantly higher incidence of MS and higher mean HOMA IR than those without. There was no significant difference in histopathological features between NAFLD with and without transaminitis. To conclude, over half of NAFLD subjects do not have transaminitis while transaminitis is present in a fifth of healthy people without fatty liver. Hence serum transaminase should not be used as screening test for NAFLD. NAFLD patients with transaminitis had a higher incidence of MS and insulin resistance than those without. However, there was no significant difference in histopathological features between these two groups.