Histology Of Nodules Research Articles

An ensemble deep learning model for risk stratification of invasive lung adenocarcinoma using thin-slice CT

Lung cancer screening using computed tomography (CT) has increased the detection rate of small pulmonary nodules and early-stage lung adenocarcinoma. It would be clinically meaningful to accurate assessment of the nodule histology by CT scans with advanced deep learning algorithms. However, recent studies mainly focus on predicting benign and malignant nodules, lacking of model for the risk stratification of invasive adenocarcinoma. We propose an ensemble multi-view 3D convolutional neural network (EMV-3D-CNN) model to study the risk stratification of lung adenocarcinoma. We include 1075 lung nodules (≤30 mm and ≥4 mm) with preoperative thin-section CT scans and definite pathology confirmed by surgery. Our model achieves a state-of-art performance of 91.3% and 92.9% AUC for diagnosis of benign/malignant and pre-invasive/invasive nodules, respectively. Importantly, our model outperforms senior doctors in risk stratification of invasive adenocarcinoma with 77.6% accuracy [i.e., Grades 1, 2, 3]). It provides detailed predictive histological information for the surgical management of pulmonary nodules. Finally, for user-friendly access, the proposed model is implemented as a web-based system (https://seeyourlung.com.cn).

A randomized, open-label study of the tolerability and efficacy of one or three daily doses of ivermectin plus diethylcarbamazine and albendazole (IDA) versus one dose of ivermectin plus albendazole (IA) for treatment of onchocerciasis.

Onchocerciasis ("river blindness") has been targeted for elimination. New treatments that kill or permanently sterilize female worms could accelerate this process. Prior studies have shown that triple drug treatment with ivermectin plus diethylcarbamazine and albendazole (IDA) leads to prolonged clearance of microfilaremia in persons with lymphatic filariasis. We now report results from a randomized clinical trial that compared the tolerability and efficacy of IDA vs. a comparator treatment (ivermectin plus albendazole, IA) in persons with onchocerciasis. The study was performed in the Volta region of Ghana. Persons with microfiladermia and palpable subcutaneous nodules were pre-treated with two oral doses of ivermectin (150 μg/kg) separated by at least 6 months prior to treatment with either a single oral dose of ivermectin 150 μg/kg plus albendazole 400 mg (IA), a single oral dose of IDA (IDA1, IA plus diethylcarbamazine (DEC. 6 mg/kg) or three consecutive daily doses of IDA (IDA3). These treatments were tolerated equally well. While adverse events were common (approximately 30% overall), no severe or serious treatment-emergent adverse events were observed. Skin microfilariae were absent or present with very low densities after all three treatments through 18 months, at which time nodules were excised for histological assessment. Nodule histology was evaluated by two independent assessors who were masked regarding participant infection status or treatment assignment. Significantly lower percentages of female worms were alive and fertile in nodules recovered from study participants after IDA1 (40/261, 15.3%) and IDA3 (34/281, 12.1%) than after IA (41/180, 22.8%). This corresponds to a 40% reduction in the percentage of female worms that were alive and fertile after IDA treatments relative to results observed after the IA comparator treatment (P = 0.004). Percentages of female worms that were alive (a secondary outcome of the study) were also lower after IDA treatments (301/574, 52.4%) than after IA (127/198, 64.1%) (P = 0.004). Importantly, some comparisons (including the reduced % of fertile female worms after IDA1 vs IA treatment, which was the primary endpoint for the study) were not statistically significant when results were adjusted for intraclass correlation of worm fertility and viability for worms recovered from individual study participants. Results from this pilot study suggest that IDA was well tolerated after ivermectin pretreatment. They also suggest that IDA was more effective than the comparator treatment IA for killing or sterilizing female O. volvulus worms. No other short-course oral treatment for onchocerciasis has been demonstrated to have macrofilaricidal activity. However, this first study was too small to provide conclusive results. Therefore, additional studies will be needed to confirm these promising findings. The study is registered at Cinicaltrials.gov under the number NCT04188301.

Nodulation in Rhynchosia schimperi: A Rare Legume of Indian Thar Desert

Rhycnhosia schimperi Hochst. ex Boiss. is a rare plant of Indian Thar Desert and mostly confined to the Jaisalmer and Barmer district of Rajasthan. There are least information is available on the nodulation in it. In India the comprehensive study on nodulation in native legumes of Thar Desert was done by Gehlot et. al. in 2012. In which they have reported nodulation in more than 30 native legumes (excluding Rhynchosia schimperi) with detail study on the morphology & histology of nodules and their associated rhizobia. The present investigation was done to know the nodulation status as well as the morphology & histology of nodules and their associated micro-symbionts in Rhynchosia schimperi. The study reveal good amount of nodulation was found in it. The nodules were found perennial and mucunoid type and mainly two types of bacteria viz. fast growing probably Ensifer sp. and slow growing Badirhizobium sp. were found in it.

MRI Features Associated with Histology of Benign Prostatic Hyperplasia Nodules: Generation of a Predictive Model.

Background: Histologic phenotypic variation of benign prostatic hyperplasia (BPH) has been hypothesized to underlie response to medical therapy. We evaluate preoperative MRI of robot-assisted simple prostatectomy (RASP) specimens and determine imaging features associated with histologic phenotype. Materials and Methods: All patients undergoing RASP from November 2015 to November 2019 with a multiparametric MRI ≤1 year before RASP were included. Patients without identifiable BPH nodules on histologic specimens were excluded. Histology slides were obtained from whole mount adenoma specimens and corresponding MRI were reviewed and graded independently by a blinded expert in BPH histopathology (D.W.S.) and an experienced radiologist specializing in prostate imaging (D.N.C.), respectively. Each nodule was assigned a phenotypic score on a 5-point Likert scale (1 = predominantly glandular; 5 = predominantly stromal) by each reviewer. Scores were compared using the sign test and univariate analysis. Signal intensity relative to background transition zone and nodule texture were noted on T2, diffusion-weighted imaging (DWI), and dynamic contrast-enhanced (DCE) imaging sequences. Univariate and multivariate stepwise linear regression analysis were conducted to identify MRI features associated with histology score. All analyses were performed using Statistical Analysis System (version 9.4). Results: A total of 99 prostate nodules in 29 patients were included. Median phenotypic scores by histology and MRI were comparable (2, interquartile range [IQR] 2-3 vs 2, IQR 2-4, respectively; p = 0.63). Histology scores were positively correlated with MRI scores (Pearson's correlation 0.84, p < 0.0001). Multivariate stepwise linear regression analysis showed that low apparent diffusion coefficient (ADC) signal intensity (p < 0.001) and DCE wash-in (p = 0.03) were positively associated with more stromal histology, whereas ADC standard deviation (p = 0.03), DCE wash-out (p = 0.001), and heterogeneous T2 texture (p = 0.003) were associated with more glandular histology. Conclusion: There is a strong correlation between MRI features and the histologic phenotype of BPH nodules. MRI may provide a noninvasive method to determine underlying BPH nodule histology.

Accessing the influence of 99mTc-Sesta-MIBI-positive thyroid nodules on preoperative localisation studies in patients with primary hyperparathyroidism

PurposeCurative treatment for primary hyperparathyroidism (PHPT) is parathyroidectomy (PTX) with removal of the hyperfunctioning gland(s). In an endemic goitre region, 35–78% of PHPT patients show concomitant thyroid disease. This study aimed to evaluate if 99mTc-sestamibi (MIBI)-positive thyroid nodules decrease sensitivity in regard to localising the hyperfunctioning parathyroid gland(s) in PHPT patients.MethodsWithin 5 years, 497 consecutive patients with biochemically proven PHPT were included in this study. The data was analysed retrospectively.ResultsIn total, 198 patients underwent PTX with thyroid surgery and 299 patients underwent sole PTX. Sensitivity of MIBI scan for PTX with and without thyroid surgery was 72.1% and 73.6%, respectively. A statistically significant difference in sensitivity of ultrasound for PTX with and without thyroid surgery (57.0% and 70.9%, respectively) was observed (p = 0.029). Thyroid nodule histology did not have a significant effect on the MIBI scan. Unilateral neck exploration (UNE) was performed in 110 patients and bilateral neck exploration (BNE) in 177 patients. The probability of surgical conversion from UNE to BNE due to incorrect localisation was 1.733 times higher in patients with thyroid nodules.ConclusionsConcomitant benign thyroid nodules did not influence MIBI sensitivity. No correlation between thyroid carcinoma and MIBI uptake was determined. However, MIBI detection of thyroid malignancy is important in patients initially being considered for minimal invasive parathyroidectomy. Sensitivity and positive predictive value of ultrasound were significantly lower in patients with thyroid nodules. The probability of conversion from UNE to BNE due to incorrect localisation was 1.733 times higher in patients with thyroid nodules.

MP22-12 MAGNETIC RESONANCE IMAGING FEATURES ASSOCIATED WITH HISTOLOGY OF BENIGN PROSTATIC HYPERPLASIA NODULES: A PREDICTIVE MODEL

You have accessJournal of UrologyImaging/Radiology: Uroradiology II (MP22)1 Sep 2021MP22-12 MAGNETIC RESONANCE IMAGING FEATURES ASSOCIATED WITH HISTOLOGY OF BENIGN PROSTATIC HYPERPLASIA NODULES: A PREDICTIVE MODEL Jessica Dai, Tara Morgan, Ramy Goueli, Daniel Parrott, Douglas Strand, Daniel Costa, Claus Roehrborn, and Jeffrey Gahan Jessica DaiJessica Dai More articles by this author , Tara MorganTara Morgan More articles by this author , Ramy GoueliRamy Goueli More articles by this author , Daniel ParrottDaniel Parrott More articles by this author , Douglas StrandDouglas Strand More articles by this author , Daniel CostaDaniel Costa More articles by this author , Claus RoehrbornClaus Roehrborn More articles by this author , and Jeffrey GahanJeffrey Gahan More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002013.12AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Histologic phenotypic variation of benign prostatic hyperplasia (BPH) has been previously described and is hypothesized to underlie response to medical therapy. In this study, we evaluate pre-operative magnetic resonance imaging (MRI) of robotic simple prostatectomy (RASP) specimens and determine imaging features associated with histologic phenotype. METHODS: All patients undergoing RASP from 11/2015 to 11/2019 with multiparametric MRI ≤1 year before surgery were included. Those with no obvious BPH nodules on histologic specimens were excluded. Histology slides and corresponding MRI were reviewed independently by a blinded cell biology Ph.D. and radiologist, respectively. Each nodule was assigned a phenotypic score on a 5-point Likert scale (1=predominantly glandular, 5=predominantly stromal). Scores were compared using the sign test and univariate analysis. Signal intensity relative to transition zone and nodule texture were noted on T2, diffusion-weighted imaging (DWI), and dynamic contrast-enhanced imaging (DCE) sequences (Figure 1). Univariate and multiple stepwise linear regression analysis were conducted to identify MRI features associated with histology score. All analyses were performed using Statistical Analysis System (SAS v 9.4). RESULTS: 99 prostate nodules in 29 patients were included. Median phenotypic scores by histology and MRI were comparable (2, IQR 2-3 vs. 2, IQR 2-4, respectively; p=0.63). Histology scores were positively associated with MRI scores on univariate analysis (p <0.0001). Multiple stepwise linear regression analysis showed apparent diffusion coefficient (ADC) low signal intensity and DCE wash-in to be positively associated with more stromal histology score, and ADC SD, DCE wash-out, and heterogeneous T2 texture to be negatively associated with more stromal histology score (Table 1). CONCLUSIONS: There is strong correlation between MRI features and the histologic phenotype of BPH nodules. MRI may provide a non-invasive method to determine underlying BPH nodule histology. Source of Funding: DK115477 (DWS) © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e395-e396 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Jessica Dai More articles by this author Tara Morgan More articles by this author Ramy Goueli More articles by this author Daniel Parrott More articles by this author Douglas Strand More articles by this author Daniel Costa More articles by this author Claus Roehrborn More articles by this author Jeffrey Gahan More articles by this author Expand All Advertisement Loading ...

Comparison of Repeated Doses of Ivermectin Versus Ivermectin Plus Albendazole for the Treatment of Onchocerciasis: A Randomized, Open-label, Clinical Trial.

BackgroundImproved treatment for onchocerciasis is needed to accelerate onchocerciasis elimination in Africa. Aiming to better exploit registered drugs, this study was undertaken to determine whether annual or semiannual treatment with ivermectin (IVM; 200 µg/kg) plus albendazole (ALB; 800 mg single dose) is superior to IVM alone.MethodsThis trial was performed in Ghana and included 272 participants with microfilariae (MF), who were randomly assigned to 4 treatment arms: (1) IVM annually at 0, 12, and 24 months; (2) IVM semiannually at 0, 6, 12, 18, and 24 months; (3) IVM+ALB annually; or (4) IVM+ALB semiannually. Microfiladermia was determined pretreatment and at 6, 18, and 36 months. The primary outcome was the proportion of fertile and viable female worms in onchocercomata excised at 36 months.ResultsPosttreatment nodule histology showed that 15/135 (11.1%), 22/155 (14.2%), 35/154 (22.7%), and 20/125 (16.0%) living female worms had normal embryogenesis in the IVM annual, IVM semiannual, IVM+ALB annual, and IVM+ALB semiannual groups, respectively (P = .1229). Proportions of dead worms also did not differ between the 4 groups (P = .9198). Proportions of patients without MF at 36 months (1 year after the last treatment) were 35/56 (63%) after annual IVM, 42/59 (71%) after semiannual IVM, 39/64 (61%) after annual IVM+ALB, and 43/53 (81%) after semiannual IVM+ALB.ConclusionsThe combination treatment of IVM plus ALB was no better than IVM alone for sterilizing, killing adult worms, or achieving sustained MF clearance. However, semiannual treatment was superior to annual treatment for achieving sustained clearance of Onchocerca volvulus MF from the skin (P = .024).Clinical Trials RegistrationISRCTN50035143

Italian consensus for the classification and reporting of thyroid cytology: the risk of malignancy between indeterminate lesions at low or high risk. A systematic review and meta-analysis.

Italian consensus for the classification and reporting of thyroid cytology has proposed to discriminate the cancer prevalence of high (Tir 3B) vs. low (Tir 3A) risk indeterminate nodules. To obtain more robust evidence on this topic, we performed a meta-analysis of the Odds Ratio (OR) of malignancy of Tir 3B vs. Tir 3A nodules. A comprehensive literature exploration of online databases was conducted until May 2018. Original articles reporting histology of nodules cytologically classified as Tir 3A and Tir 3B were eligible. Pooled cancer prevalence in Tir 3A and Tir 3B, and OR of Tir 3B vs. Tir 3A were calculated. The search revealed 95 articles, and 10 were included for the meta-analysis. Overall, 1168 indeterminate lesions were reported (441 Tir 3A and 727 Tir 3B), of which 391 were cancers. The pooled cancer prevalence was 17% in Tir 3A and 47% in Tir 3B. The OR of Tir 3B vs. Tir 3A was 4.24 (95% CI 2.75 to 6.53) with mild heterogeneity and without publication bias. When we considered non-invasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTP) as non-malignant, cancer rate was lower, and OR of Tir 3B against Tir 3A was 2.93 (95% CI 1.60 to 5.37), with no heterogeneity but with publication bias. The Italian system for thyroid cytology is reliable to assess indeterminate lesions at low and high risk, being Tir 3B associated with a cancer risk significantly higher than Tir 3A, also when considering NIFTP as non-malignant entity.

Role of Strain Elastography and Shear-Wave Elastography in a Multiparametric Clinical Approach to Indeterminate Cytology Thyroid Nodules.

BackgroundIn thyroid nodules with indeterminate cytology, further clinical assessment aimed at ruling out malignancy is often mandatory. Ancillary imaging techniques and genetic mutation analysis can improve the risk stratification of such lesions, thereby facilitating the clinician’s decision to undertaken surgery or simple follow-up. The aim of this study was to evaluate the diagnostic performance of shear-wave elastography (SW), strain elastography (ELX 2/1), conventional ultrasound (US), contrast-enhanced ultrasound (CEUS), and BRAF V600E mutation analysis in the aforementioned lesions.Material/MethodsWe enrolled 81 patients, each with 1 indeterminate-cytology thyroid nodule. Thyroid function, thyroperoxidase antibodies and calcitonin were known in each case. SW, ELX 2/1, US, CEUS, and BRAF mutation analysis were subsequently performed, followed by a second FNAB. If the lesion was not downgraded to benign, surgery was recommended and histological reports collected.ResultsThere were 28 nodules (34%) that proved benign on the second FNAB; 38 nodules (47%) underwent surgery (17 benign, 21 malignant), and 15 nodules (19%) refused surgery. The only techniques related to histological outcome were US (AUC=0,766), ELX 2/1 (AUC=0.701), and BRAF analysis (AUC=0.762). ELX 2/1 and SW reports were not correlated with each other (P=0.45). A scoring system taking into account all the variables considered performed better than the single variables alone (AUC=0.831).ConclusionsIn indeterminate-cytology thyroid lesions, repeating FNAB can avoid unnecessary surgery. ELX 2/1 seems to perform better than SW in distinguishing malignancy; these techniques could, however, be complementary in describing such lesions. A multiparametric approach appears the most accurate in predicting nodule histology.

The tight-adhesion proteins TadGEF of Bradyrhizobium diazoefficiens USDA 110 are involved in cell adhesion and infectivity on soybean roots

Adhesion of symbiotic bacteria to host plants is an essential early step of the infection process that leads to the beneficial interaction. In the Bradyrhizobium diazoefficiens-soybean symbiosis few molecular determinants of adhesion are known. Here we identified the tight-adhesion gene products TadGEF in the open-reading frames blr3941–blr3943 of the B. diazoefficiens USDA 110 complete genomic sequence. Predicted structure of TadG indicates a transmembrane domain and two extracytosolic domains, from which the C-terminal has an integrin fold. TadE and TadF are also predicted as bearing transmembrane segments. Mutants in tadG or the small cluster tadGEF were impaired in adhesion to soybean roots, and the root infection was delayed. However, nodule histology was not compromised by the mutations, indicating that these effects were restricted to the earliest contact of the B. diazoefficiens and root surfaces. Knowledge of preinfection determinants is important for development of inoculants that are applied to soybean crops worldwide.

The many faces of pulmonary metastases of osteosarcoma: Retrospective study on 283 lesions submitted to surgery

ObjectiveCT is the recommended technique for the detection of pulmonary metastases in patients affected by osteosarcoma, though claimed to show several limits compared to manual palpation. We retrospectively analyzed CT features of suspected lesions submitted to surgery to address its current accuracy and to investigate criteria for predicting histology. Materials and methodsCT scans of 70 patients submitted to thoracotomy between 2007–2013 were reviewed. Overall, 123 thoracotomies were performed and 283 lesions seen on CT were resected. Shape, size, presence and type of calcification, evolution of each lesion were analyzed. Number and histology of nodules detected at thoracotomy were recorded and compared to CT data. Results234/283—82.7% Lesions were metastases; 143—61.1% were calcified; most metastases were nodular (201/234—85.9%), but in 33/234—14.1% other findings were detected (striae, consolidations, pleural plaques/masses, cavitations, ground glass opacities, irregular shapes, halo sign). Malignant lesions were more frequently calcified, larger, with progression over time—p<0.0001. Manual palpation identified 314 lesions, 248 metastatic—79.0%: CT missed 31/314—9.9% lesions, whereof 14/31—45.2% were metastases. ConclusionsThough most lesions are nodular and calcified, up to 40% are not calcified and atypical findings are not uncommon (14.1%). The identification of the atypical radiological presentation of metastases could be the key for improving CT accuracy.

Thoracoscopic Versus Open Pulmonary Metastasectomy: A Prospective, Sequentially Controlled Study

Patients with limited metastatic disease in the lung may benefit from metastasectomy. Thoracotomy is considered the gold standard, and video-assisted thoracoscopic surgery (VATS) is controversial because nonimaged nodules may be missed when bimanual palpation is restricted. Against guideline recommendations, metastasectomy with therapeutic intent is now performed by VATS by 40% of thoracic surgeons surveyed. The evidence base for optimal surgical approach is limited to case series and registries, and no comparative surgical studies were observer blinded. Patients considered eligible for pulmonary metastasectomy by VATS prospectively underwent high-definition VATS by one surgical team, followed by immediate thoracotomy with bimanual palpation and resection of all palpable nodules by a second surgical team during the same anesthesia. Both surgical teams were blinded during preoperative evaluation of CT scans and during surgery. Primary end points were number and histology of nodules detected. During a 12-month period, 37 patients were included. Both surgical teams observed exactly 55 nodules suspicious of metastases on CT scans. Of these, 51 nodules were palpable during VATS (92%), and during subsequent thoracotomy 29 additional nodules were resected: Six (21%) were metastases, 19 (66%) were benign lesions, three (10%) were subpleural lymph nodes and one was a primary lung cancer. Modern VATS technology is increasingly used for pulmonary metastasectomy with therapeutic intent, but several nonimaged, and therefore unexpected, nodules are frequently found during subsequent observer-blinded thoracotomy. A substantial proportion of these nodules are malignant, and, despite modern imaging and surgical technology, they would have been missed if VATS was used exclusively for metastasectomy with therapeutic intent.

Utilidade do PET/CT na caracterização do nódulo solitário pulmonar

Background – The cancer of lung/trachea and bronchi is the leading cause of death from cancer in the European Union. Dual time in Positron Emission Tomography/Computed Tomography (PET/CT) technique has been referred in some articles as a great value in pulmonary cancer diagnosis. The aim of this study is to evaluate the PET/CT diagnostic accuracy with dual time in characterization of solitary pulmonary nodule (NSP), analyzing the nodule histology and size. Methodology – There were 115 NSP analyzed, a total of 110 patients, where 65 were malignant. Two images were acquired, one with an average time of 52 minutes and another one with 125 minutes after 18F-2-fluoro-2-deoxy-Dglucose (18F-FDG) injection. The standard uptake value (SUVmax) and percentage of changes in SUVmax (%variation) were obtained to analyse those images. Results – The %variation shows higher values of diagnostic accuracy than when analyzing SUVmax separately. However there are significant differences in histology and SUVmax, registering also an increase of SUVmax2 in malignant pathologies comparatively with SUVmax1. Conclusion – Dual time technique showed to be more efficient in NSP characterization than when analyzing only one image.

Do characteristics of pulmonary nodules on computed tomography in children with known osteosarcoma help distinguish whether the nodules are malignant or benign?

PurposeTo determine if selected computed tomography (CT) characteristics of pulmonary nodules in pediatric patients with osteosarcoma can help distinguish the nodules as benign or malignant. MethodsThe institutional review board approved this HIPAA (Health Insurance Portability and Accountability Act-compliant, retrospective study of 30 pediatric osteosarcoma patients (median age 14 years, range 8-22) who underwent chest CT with resection of 117 pulmonary nodules from January 2001 to December 2006. Two pediatric radiologists and one chest radiologist independently and retrospectively reviewed the CT scans and classified nodules as benign, malignant, or indeterminate on the basis of nodule size, laterality, number, location, growth, density, margin appearance, and calcification. Generalized estimating equations were used to examine which characteristics were independent predictors of nodule malignancy. ResultsOf the 117 nodules, 80 (68%) were malignant and 37 (32%) were benign by pathologic review. The readers correctly classified 93% to 94% of the malignant nodules. For benign lesions, the results were not as accurate, with the readers correctly classifying only 11% to 30% of lesions. Most of the benign lesions were classified as indeterminate by the readers (54%-65%). Nodule size (≥5 mm) and the presence of calcifications were associated with an increased probability of malignancy (P < .05). ConclusionOn chest CT, nodule size 5 mm or greater and the presence of calcifications are associated with an increased probability of malignant nodule histology in pediatric patients with osteosarcoma. However, nodule characteristics, apart from size and calcification, at chest CT cannot reliably distinguish benign from malignant pulmonary nodules in these patients.

The root-nodule symbiosis between Sarothamnus scoparius L. and its microsymbionts.

When nitrogen fixing root nodules are formed, Sarothamnus scoparius (broom) is inoculated with its microsymbionts. Nodules studied under light and electron microscopy exhibited typical indeterminate nodule histology with apical, persistent meristem, age gradient of nodule tissues, and open vascular bundles, and also with some particular features such as: the presence of mitotic activity in the infected meristematic cells, lack of infection threads, distribution of bacteria by process of host cell division, and occurrence of a large bacteroid zone only with infected cells. The results of cross-inoculation tests have shown a broad host range for S. scoparius microsymbionts including not only the native host but also species such as: Lupinus luteus, Ornithopus sativa, Lotus corniculatus, Genista tinctoria, Chamaecitisus ratisbonensis, Macroptilium atropurpureum, and Phaseolus vulgaris. In addition, our data established a close symbiotic relationship of S. scoparius nodulators to Bradyrhizobium sp. (Lupinus) by comparison of the partial sequence of nodC gene of the strain CYT7, specific for the broom, to those from Bradyrhizobium sp. (Lupinus) strain D1 and others available in the public databases.

Nitrogenase divarication with histological attributes distinctive for glycosylated aerial stem nodules and nitrosylated root nodules of sesbania

Abstract Exceptional symbiotic nitrogen fixation with Sesbania has provided high soil fertility for many past centuries of paddy rice production. Unique stem nodulation results in high nitrogenase activity levels of S. rostrata, Brem, during rapid growth in continuously flooded rice fields that greatly disfavor legume root nodulation and this functional development. The objective of this study was to determine plant nutrient interactions that influence contrasting root and aerial stem nodule histology governing effective nitrogenase activity levels and nitrogen fixation. Top growth, nodulation, and nitrogenase activity levels were significantly increased with increased available soil P. Response to K levels and Ca additions resulted only when soil P was adequate in all treatment combinations. However, there was no significant correlation between fresh nodule weight, nitrogenase activity, and nodules plant‐1 for both root nodules and aerial stem nodules. Nodule histology was highly contrastive with nodule type and Rhizobium morphology, cytosol composition, and governing enzyme activity levels. Distinctive nonpleomorphic cocci bacteroids of functional aerial stem nodules have tentative designation as Azorhizobium caulinodans gen. nov. sp. nov.

Soil nitrification induced nitrosylleghemoglobin with repressed nitrogenase activity during re‐growth of forage siratro [Macroptiuum atro‐purpureum(DC) Urb

Abstract Accelerated soil microbial nitrification is associative with rapid aerobic decomposition of highly proteinaceous, senescent legume nodules. Resultant high soil nitrate levels repress leghemoglobin‐nitrogenase activity levels and inhibit symbiotic nitrogen fixation. Objectives of this study were to determine nodule histology and enzymatic transformations of leghemoglobin catabolism occurring during rigorous defoliation and rapid regrowth of forage Siratro [Macroptilium atropurpureum (DC) Urb)]. Growth, nodulation and nitrogenase activity increased quadradically to 170 day‐age. Proportions of histochromic pink‐red nodule centrales correlated with nitrogenase activity levels. Induced nitrosylleghemoglobin‐choleglobin synthesis, with greenishbrown nodule centrales, resulted from increased soil nitrification during decomposition of senescent nodules following defoliation. Nodule histology utilized leucofuchsin Schiff‐Base specific stain interactions with cytosol glycan conjugates. Resultant magenta ch...

Exceptional forage regrowth, nodulation and nitrogenase activity of kudzu (Pueraria lobata(Willd.) Ohivi) grown on eroded Dougherty loam subsoil

Abstract Kudzu (Pueraria lobata (Willd.) Ohivi) is a hardy, perennial deciduous legume and a high protein, preferred forage for all livestock and poultry. However, when underutilized for pasturage, Kudzu's unrestricted, robust climbing vine development is impressive to highway travelers throughout the southeastern United States. Kudzu was effectively utilized for erosion control and soil improvement following introduction to the U.S. from Japan in 1876. Unique characteristics include distinctive nodulation with high nitrogenase activity levels, rapid regrowth of pastured foliage, profuse xylem transport of ureide components adjunctive to nitrogen fixation, and the very useful characteristic of vigorous, productive adaptiveness to eroded, low fertility soils. The objective of this study was to determine plant nutrient interactions influencing Kudzu regrowth, nodulation, nodule histology, and xylem exudate components. Available soil phosphorus within eroded, Dougherty loam subsoil was the limiting plant nut...

Soil constraints with distinctive coralloid nodulation and nitrogen fixation of “Mecca” alfalfa

Abstract The evolutionary origin center of alfalfa within the extensive subhumid Transcaucasia has been a valuable source of Medicago spp. for development of improved alfalfa cultivars. Centuries of natural outcrossing within the perennial, allogamous Medicago species complex resulted in numerous polymorphic plants with desirable genetic characteristics adaptive to harsh climatic and soil environs. Characteristic large coralioid noduiation of M. media (M. falcata X M. sativa) provides means for improved symbiotic nitrogen fixation. The compositae, “Mecca”, (M. sativa spp. falcata Arcemgeli) was selected for desirable noduiation and nitrogen fixation attributes. The objective of this study was to determine soil fertility factors governing its nodulation, nodule histology and cytosol enzymology essential for symbiotic nitrogen fixation. Adequate available soil P was a first limiting factor. Growth, noduiation and nitrogen fixation resulted in significant response to increases in K and Ca only with P combina...

Effects of P, Ca with four k levels on nodule histology, nitrogenase activity and improved “Spanco”; peanut yields

Abstract Soil fertility with effective nodulation and favorable mycorrhizal colonization favor production of high quality, sound mature peanuts within the warm humid and tropical regions of the world. Total top growth of well nodulated and mycorrhizal infected Spanco peanuts, grown on Dougherty sand loam, was depressed with only soil K additions but increased linearly with increased K amendment when combined with P + Ca. Mature peanut yields plant‐1 increased with K additions only when combined with P, Ca or P + Ca treatments. Highly significant linear increases of improved marketable, mycotoxin free, sound mature kernels (SMK) resulted with K additions when combined with P and Ca. Nodules plant‐1 increased significantly with Ca, P and P + Ca. Nitro‐genase = 1.7 top growth + 3.69 nut yield + 1.12% SMK + 3.89 nodules, R2 = 0.78 and C.V. = 13.2%. Plant nutrient content of nodule cytosol increased significantly with soil addition of the corresponding element. Na decreased significantly with increased K. Nitr...