Calcification Rates Research Articles

Ocean acidification affects physiology of coccolithophore Emiliania huxleyi and weakens its mechanical resistance to copepods

The effects of ocean acidification (OA) on coccolithophore's photosynthesis, calcification rates, and growth have been extensively studied. However, how the intracellular Ca2+, mechanical properties and chemical composition of the coccoliths are affected by OA have not yet been investigated. This study tries to fill these gaps using Emiliania huxleyi as a model coccolithophore. When the seawater pCO2 increased from 400 μatm to 1200 μatm, the intracellular Ca2+ and coccolith area were reduced by 66% and 36%, respectively. Single-cell mapping by atomic force microscopy revealed that the modulus and hardness of coccolith decreased from 23.6 ± 0.2 GPa to 12.0 ± 5.5 GPa and from 0.53 ± 0.15 GPa to 0.20 ± 0.06 GPa, respectively. Additionally, the proportional organic matter and silicon in the coccolith surfaces increased with pCO2. The copepods Acartia pacifica fed on more E. huxleyi grown at higher pCO2. Our study implies that OA could change coccolithophore's competitive interactions with other phytoplankton and ultimately influence carbon export to the deep ocean.

Effect of low-calcium and standard-calcium dialysate on serum calcium, phosphorus and full-segment parathyroid hormone in patients on peritoneal dialysis: A retrospective observational study.

To investigate the effects of low-calcium and standard-calcium dialysate in patients with chronic kidney disease on peritoneal dialysis, and find out which dialysate has less vascular calcification effect. A total of 141 patients who had undergone peritoneal dialysis (PD) for 2 years in the PD centre from January 2012 to December 2017 were included and divided into two groups according to the calcium concentration of the PD fluid used. There were 79 cases in the low-calcium group, with a dialysate calcium concentration of 1.25 mmol/L and 62 cases in the standard-calcium group, with a dialysate calcium concentration of 1.75 mmol/L. The demographic characteristics and clinical information before initiation of PD were collected and compared between the two groups. Information on the serum calcium, phosphorus and PTH, systolic and diastolic blood pressures and the use of antihypertensive and phosphate-lowering drugs in the second year of dialysis was also collected and compared between the two groups. Vascular calcification was assessed in patients on PD treatment. The mean serum calcium concentrations before initiation of PD in the low- and standard-calcium groups were 1.94 ± 0.27 and 1.89 ± 0.28 mmol/L, respectively. The serum calcium concentrations after PD were 2.30 ± 0.21 and 2.41 ± 0.23 mmol/L, respectively. After PD, the serum calcium concentration in both groups was significantly increased (p < 0.05). The serum calcium concentration in the low-calcium group after PD treatment was lower than that in the standard-calcium group, and the difference was statistically significant (p < 0.05). Compared with the standard-calcium group, patients in the low-calcium group had significantly higher parathyroid hormone concentrations (p < 0.05). More types of phosphate-lowering drugs were used (59.49%) in the low-calcium group than that in the standard-calcium group (35.48%; p < 0.05). The number of antihypertensive drug usage were also higher in the low-calcium group, and the difference was statistically significant (p < 0.05). As for the vascular calcification effect, the two groups have shown no statistical difference in abdominal aortic calcification rate, carotid arteriosclerosis rate and aortic arch calcification rate (p < 0.05). We found that low-calcium PD fluid may increase the PTH level and the proportion of CKD patients using antihypertensive drug and phosphorus-lowering drug, but the vascular calcification effect of the low and standard calcium PD fluid needs further exploration. This paper provides new evidence for the choice of dialysate for PD, low-calcium dialysate has no outstanding advantages for long term dialysis.

Correction to: Calcification rates in the lower photic zone and their ecological implications

Correction to: Calcification rates in the lower photic zone and their ecological implications

Impact of ocean acidification on shells of the abalone species Haliotis diversicolor and Haliotis discus hannai

Ocean acidification (OA) results from the absorption of anthropogenic CO2 emissions by the ocean and threatens the survival of many marine calcareous organisms including molluscs. We studied OA effects on adult shells of the abalone species Haliotis diversicolor and Haliotis discus hannai that were exposed to three pCO2 conditions (ambient, ∼880, and ∼1600 μatm) for 1 year. Shell periostracum corrosion under OA was observed for both species. OA reduced shell hardness and altered the nacre ultrastructure in H. diversicolor, making its shells more vulnerable to crushing force. OA exposure did not reduce the shell hardness of H. discus hannai and did not alter nacre ultrastructure. However, the reduced calcification also decreased its resistance to crushing force. Sr/Ca in the shell increased with rising calcification rate. Mg/Ca increased upon OA exposure could be due to a complimentary mechanism of preventing shell hardness further reduced. The Na/Ca distribution between the aragonite and calcite of abalone shells was also changed by OA. In general, both abalone species are at a greater risk in a more acidified ocean. Their shells may not provide sufficient protection from predators or to transportation stress in aquaculture.

Seasonal upwelling conditions promote growth and calcification in reef-building coralline algae.

Crustose coralline algae (CCA) are important components of reef ecology contributing to reef framework construction. However, little is known about how seasonal upwelling systems influence growth and calcification of tropical CCA. We assessed marginal and vertical growth and net calcification rates of two dominant but morphologically different reef-building CCA, Porolithon antillarum and Lithophyllum cf. kaiseri, in a shallow coral reef of the Colombian Caribbean during upwelling and non-upwelling seasons. Growth and calcification rates varied seasonally with higher values during the upwelling compared to the non-upwelling (rainy) season. Annual vertical growth showed rates of 4.48 ± 1.58 and 4.31 ± 2.17 mm · y-1 , net calcification using crust growth estimates of 0.75 ± 0.30 g and 0.68 ± 0.60 g CaCO3 · cm-2 · y-1 and net calcification using the buoyant weight method of 1.49 ± 0.57 and 0.52 ± 0.11 g CaCO3 · cm-2 · y-1 in P. antillarum and L. kaiseri, respectively. Seawater temperature was inversely related with growth and calcification; however, complex oceanographic interactions between temperature and resource availability (e.g., light, nutrients, and CO2 ) are proposed to modulate CCA vital rates. Although CCA calcification rates are comparable to hard corals, CCA vertical accretion is much lower, suggesting that the main contribution of CCA to reef construction is via cementation processes. These results provide baseline data on CCA in the region and generate useful information for monitoring the impacts of environmental changes on tropical upwelling environments.

Brown seaweed Nemacystus decipiens intensifies the effects of ocean acidification on coral Montipora digitata

Photosynthetic marine macrophytes such as seaweeds have been proposed to provide habitat refugia for marine calcifiers against ocean acidification (OA) by increasing the local pH. However, the effectiveness of seaweed as a potential habitat refugia for marine calcifiers such as corals remains to be investigated. This study focused on the seaweed Nemacystus decipiens, which are widely farmed in the shallow reef lagoon of Okinawa coral reefs, Japan, and aimed to evaluate their response to high pCO2 and whether they can mitigate the effect of high pCO2 on the coral Montipora digitata. Corals were cultured with and without seaweed under control (300–400 μatm) or high pCO2 conditions (OA, 900–1000 μatm) for 2 weeks. Results showed that all photo-physiological parameters examined in the seaweed N. decipiens were not affected by high pCO2, suggesting that OA will not positively affect their productivity. The calcification rate of the coral M. digitata was found to decrease under OA and the effect was further exaggerated by the presence of seaweed. The present study suggests that farming seaweeds will not act as a potential habitat refugia for adjacent corals under future OA, but instead can exaggerate the negative effect of OA on coral calcification.

Calcification rates in the lower photic zone and their ecological implications

Calcification rates in the lower photic zone and their ecological implications

Temporal variability in seawater Sr/Ca ratios within a coral atoll as an indicator of marine calcifier community diversity

Coral reefs are marine environments where calcium carbonate production and dissolution along with photosynthesis and respiration can have a large impact on the daily biogeochemical cycles of seawater dissolved inorganic carbon (DIC), total alkalinity (TA), oxygen (O2), and major nutrients. Using seawater samples from Tetiaroa Atoll, French Polynesia, we apply isotope dilution thermal ionization mass spectrometry (ID-TIMS) to show that these daily cycles of variability extend to the dissolved seawater Sr/Ca ratio (Sr/Casw). Hourly measurements over a 27+ hour period indicate that Sr/Casw covaries with DIC and TA and exhibits up to a 2% relative difference compared to the regional Pacific Ocean source water Sr/Casw value of 8.53 mmol/mol. We hypothesize that the primary mechanism of hourly variability in Sr/Casw is carbonate precipitation/dissolution by corals and other marine calcifiers on the Tetiaroa reef, while sedimentary redox processes may significantly contribute to an apparent decoupling between net calcification rates estimated from TA compared to dissolved calcium [Ca]sw concentrations. Using a simple Rayleigh distillation model and a two-member mixing equation, we estimate the net partition coefficient of Sr (KD-Sr) for each hourly sample as a mixture of coral (aragonite; KD-Sr ∼ 1.06) and crustose coralline algae (high Mg-calcite; KD-Sr ∼ 0.39) contributions to the measured variability of [Ca]sw and Sr/Casw. As the high Mg-calcites of crustose coralline algae are (1) integral components to the structure and stability of the reef framework and (2) more soluble than aragonite under more acidic conditions, we propose that continued analyses of Sr/Casw within coral reef environments could be a useful tool for monitoring the ecological distribution and contributions of marine calcifiers on reefs as ocean warming and acidification intensify in response to anthropogenic climate change. Additionally, seasonal, interannual, and/or centennial-scale offsets between the Sr/Casw of open ocean source seawater and ambient reef seawater may have significant implications for interpreting past changes in sea surface temperatures derived from the coral Sr/Ca paleothermometer.

The Association Between Common Bile Duct Diameter and the Severity of Coronary Artery Atherosclerosis, Based on Calcium Score

Objective: The aim was to assess the relationship between the coronary calcium score and the common bile duct (CBD) diameter, to determine whether the increase in CBD diameter in patients without hepatobiliary disease could represent cardiovascular disease, or the extent of atherosclerosis in coronary arteries. Materials and Methods: The study cohort consisted of 103 patients referred for computed tomographic angiography (CTA) for coronary artery assessment. None of the patients had a gallbladder, biliary, or pancreatic disease or surgery history. The Agatston score determined the rates of arterial calcification. The diameter of the CBD was measured for a sonogram. Results: There was a statistically significant relatively strong correlation between calcium score and CBD diameter ( r = 0.44, P = .001), independent of baseline variables, such as demographics and cardiovascular risk profiles. In the multivariable regression model, advanced age (beta = 0.825, P = .005), history of hypertension (beta = 0.591, P = .034), and history of coronary stenting (beta = 1.339, P = .001) were shown to be the main determinants of CBD dilatation. Conclusion: A statistically significant correlation existed between the CBD diameter and calcium score, within the coronary arteries and this could represent a shared pathophysiology between CBD dilatation and the severity of coronary atherosclerosis.

The response of coral skeletal nano structure and hardness to ocean acidification conditions.

Ocean acidification typically reduces coral calcification rates and can fundamentally alter skeletal morphology. We use atomic force microscopy (AFM) and microindentation to determine how seawater pCO2 affects skeletal structure and Vickers hardness in a Porites lutea coral. At 400 µatm, the skeletal fasciculi are composed of tightly packed bundles of acicular crystals composed of quadrilateral nanograins, approximately 80-300 nm in dimensions. We interpret high adhesion at the nanograin edges as an organic coating. At 750 µatm the crystals are less regular in width and orientation and composed of either smaller/more rounded nanograins than observed at 400 µatm or of larger areas with little variation in adhesion. Coral aragonite may form via ion-by-ion attachment to the existing skeleton or via conversion of amorphous calcium carbonate precursors. Changes in nanoparticle morphology could reflect variations in the sizes of nanoparticles produced by each crystallization pathway or in the contributions of each pathway to biomineralization. We observe no significant variation in Vickers hardness between skeletons cultured at different seawater pCO2. Either the nanograin size does not affect skeletal hardness or the effect is offset by other changes in the skeleton, e.g. increases in skeletal organic material as reported in previous studies.

The Potential of Plant Extracts to Substitute for NSAID Drugs that can Inhibit Post-Operative Bone Healing : A Literature Review

Bone fractures are a global public health concern. Fractures are a significant burden on individuals, families, societies, and healthcare systems, because they can cause work absences, decreased productivity, disabilities, reduced quality of life, health loss, and high healthcare expenses. Bone healing is a complex process that allows the repair of broken bones without scar tissue formation. NSAIDs have long been an essential part of our strategy for pain management in post-traumatic environments. The use of nonsteroidal anti-inflammatory drugs (NSAIDs), which are frequently used by patients as both anti-inflammatory and analgesic agents, is one of these causes. NSAIDs have been investigated for a long time, with conflicting results regarding their effects on bone repairs. Most plant parts have been used as extracts, and they may have anti-inflammatory and antioxidant properties related to these conditions. From the six studies that correlated, we found that the use of plant extracts promotes bone healing by enhancing osteogenesis, the rate of calcification, and the creation and mineralization of bone calli, thereby expediting the process of new bone formation at the fracture location. These benefits may be related to the antioxidant and anti-inflammatory properties of the extracts. From these results, it can be concluded that plant extracts can potentially substitute NSAIDs as anti-inflammatory agents in postoperative bone healing.

Son dönem renal yetmezlikli hastalarda vasküler kalsifikasyon, ateroskleroz ve inflamasyon ilişkisi

Introduction: This study aims to determine the relationship between vascular calcification, carotid artery intima-media thickness (CIMT) and malnutrition with inflammatory parameters in dialysis patients.&#x0D; Materials and Methods: 140 CKD patients and 44 healthy controls were included in the study. CIMT was measured by ultrasonography. Valvular calcification was assessed by echocardiography and vascular calcification scores (VCS) were done based on the radiograms. Biochemical parameters were assessed using routine laboratory methods. Subjective global assessment (SGA) was used to evaluate malnutrition.&#x0D; Results: In the study, VCS showed no differences between hemodialysis (HD) and peritoneal dialysis (PD) patients (1.84±2.35 for HD, 1.77±1.64 for PD; p:0.83). CIMT, Osteopontin (OPN), interleukin-6 (IL-6) and homocysteine were significantly different in both dialysis groups compared to healthy controls. The Mean carotid intima-media thickness (m-CIMT) was higher in HD patients compared to PD group. CIMT, vascular calcification and SGA scores showed positive correlation with age, dialysis duration and valvular calcification grades, and negative correlation with albumin levels. A positive correlation between SGA scores and high-sensitive C-reactive protein (hs-CRP) levels was also noted. On multiple regression analysis, m-CIMT was independently associated with age, VCS and albumin levels. VCS was found to be independently associated with only albumin levels.&#x0D; Conclusion: Vascular and valvular calcification, an indicator of cardiovascular mortality and morbidity in dialysis patients, was found to be significantly associated with malnutrition. We found higher rates of valvular calcification in patients with vascular calcification. Malnutrition was more prominent in these patients.

Ontogenetic differences in the response of the cold-water coral Caryophyllia huinayensis to ocean acidification, warming and food availability

Cold-water corals (CWCs) are considered vulnerable to environmental changes. However, previous studies have focused on adult CWCs and mainly investigated the short-term effects of single stressors. So far, the effects of environmental changes on different CWC life stages are unknown, both for single and multiple stressors and over long time periods. Therefore, we conducted a six-month aquarium experiment with three life stages of Caryophyllia huinayensis to study their physiological response (survival, somatic growth, calcification and respiration) to the interactive effects of aragonite saturation (0.8 and 2.5), temperature (11 and 15 °C) and food availability (8 and 87 μg C L−1). The response clearly differed between life stages and measured traits. Elevated temperature and reduced feeding had the greatest effects, pushing the corals to their physiological limits. Highest mortality was observed in adult corals, while calcification rates decreased the most in juveniles. We observed a three-month delay in response, presumably because energy reserves declined, suggesting that short-term experiments overestimate coral resilience. Elevated summer temperatures and reduced food supply are likely to have the greatest impact on live CWCs in the future, leading to reduced coral growth and population shifts due to delayed juvenile maturation and high adult mortality.

High physiological function for corals with thermally tolerant, host-adapted symbionts.

The flexibility to associate with more than one symbiont may considerably expand a host's niche breadth. Coral animals and dinoflagellate micro-algae represent one of the most functionally integrated and widespread mutualisms between two eukaryotic partners. Symbiont identity greatly affects a coral's ability to cope with extremes in temperature and light. Over its broad distribution across the Eastern Pacific, the ecologically dominant branching coral, Pocillopora grandis, depends on mutualisms with the dinoflagellates Durusdinium glynnii and Cladocopium latusorum. Measurements of skeletal growth, calcification rates, total mass increase, calyx dimensions, reproductive output and response to thermal stress were used to assess the functional performance of these partner combinations. The results show both host-symbiont combinations displayed similar phenotypes; however, significant functional differences emerged when exposed to increased temperatures. Negligible physiological differences in colonies hosting the more thermally tolerant D. glynnii refute the prevailing view that these mutualisms have considerable growth tradeoffs. Well beyond the Eastern Pacific, pocilloporid colonies with D. glynnii are found across the Pacific in warm, environmentally variable, near shore lagoonal habitats. While rising ocean temperatures threaten the persistence of contemporary coral reefs, lessons from the Eastern Pacific indicate that co-evolved thermally tolerant host-symbiont combinations are likely to expand ecologically and spread geographically to dominate reef ecosystems in the future.

The Role of Poly-glycerol Sebacate/Gelatin Coating Layer on Biological Features and Calcification Rate of 3D Melt-Molded Antibacterial Scaffold for Heart Valve Tissue Engineering

The Role of Poly-glycerol Sebacate/Gelatin Coating Layer on Biological Features and Calcification Rate of 3D Melt-Molded Antibacterial Scaffold for Heart Valve Tissue Engineering

Bone calcification rate as a factor of craniofacial transformations in salmonid fish: Insights from an experiment with hormonal treatment of calcium metabolism.

Adaptation to different environments can be achieved by physiological shifts throughout development. Hormonal regulators shape the physiological and morphological traits of the evolving animals making them fit for the particular ecological surroundings. We hypothesized that the artificially induced hypersynthesis of calcitonin and parathyroid hormone mutually influencing calcium metabolism could affect bone formation during early ontogeny in fish imitating the heterochrony in craniofacial ossification in natural adaptive morphs. Conducting an experiment, we found that the long-standing treatment of salmonid juveniles with high doses of both hormones irreversibly shifts the corresponding hormone status for a period well beyond the time scale for total degradation of the injected hormone. The hormones program the ossification of the jaw suspension bones and neurocranial elements in a specific manner affecting the jaws position and pharingo-branchial area stretching. These morphological shifts resemble the adaptive variants found in sympatric pelagic and demersal morphs of salmonids. We conclude that solitary deviations in the regulators of calcium metabolism could determine functional morphological traits via transformations in skeletal development.

Multimodality Imaging of Aortic Valve Calcification and Function in a Murine Model of Calcific Aortic Valve Disease and Bicuspid Aortic Valve.

Calcific aortic valve disease (CAVD) is a prevailing disease with increasing occurrence and no known medical therapy. Dcbld2-/- mice have a high prevalence of bicuspid aortic valve (BAV), spontaneous aortic valve calcification, and aortic stenosis (AS). 18F-NaF PET/CT can detect the aortic valve calcification process in humans. However, its feasibility in preclinical models of CAVD remains to be determined. Here, we sought to validate 18F-NaF PET/CT for tracking murine aortic valve calcification and leveraged it to examine the development of calcification with aging and its interdependence with BAV and AS in Dcbld2-/- mice. Methods: Dcbld2-/- mice at 3-4 mo, 10-16 mo, and 18-24 mo underwent echocardiography, 18F-NaF PET/CT (n = 34, or autoradiography (n = 45)), and tissue analysis. A subset of mice underwent both PET/CT and autoradiography (n = 12). The aortic valve signal was quantified as SUVmax on PET/CT and as percentage injected dose per square centimeter on autoradiography. The valve tissue sections were analyzed by microscopy to identify tricuspid and bicuspid aortic valves. Results: The aortic valve 18F-NaF signal on PET/CT was significantly higher at 18-24 mo (P < 0.0001) and 10-16 mo (P < 0.05) than at 3-4 mo. Additionally, at 18-24 mo BAV had a higher 18F-NaF signal than tricuspid aortic valves (P < 0.05). These findings were confirmed by autoradiography, with BAV having significantly higher 18F-NaF uptake in each age group. A significant correlation between PET and autoradiography data (Pearson r = 0.79, P < 0.01) established the accuracy of PET quantification. The rate of calcification with aging was significantly faster for BAV (P < 0.05). Transaortic valve flow velocity was significantly higher in animals with BAV at all ages. Finally, there was a significant correlation between transaortic valve flow velocity and aortic valve calcification by both PET/CT (r = 0.55, P < 0.001) and autoradiography (r = 0.45, P < 0.01). Conclusion: 18F-NaF PET/CT links valvular calcification to BAV and aging in Dcbld2-/- mice and suggests that AS may promote calcification. In addition to addressing the pathobiology of valvular calcification, 18F-NaF PET/CT may be a valuable tool for evaluation of emerging therapeutic interventions in CAVD.

Evaluation of Histopathologic Alterations in First-trimester COVID-19-positive Pregnancies Ending in Abortion.

This study aims to evaluate histopathologic alterations and the presence of chronic histiocytic intervillositis in first-trimester coronavirus-2019 (COVID-19)-positive pregnancies ending in abortion, compared with those at a similar gestational week and undergoing curettage before the pandemic. This retrospective case-control study consisted of 9 patients who were infected with COVID-19 and undergoing curettage for abortion between April 2020 and January 2021. The control group consisted of 34 patients with a similar gestational age who underwent curettage for abortion before August 2019. Demographic and clinical data were recorded. A histopathologic examination of the placental specimens was performed. The CD68 immunostaining was performed to detect intravillous and intervillous histiocytes. At the time of diagnosis of COVID 19, 7 patients (77.8%) of COVID-19-positive women had symptoms with the most common symptoms of fatigue (66.7%) and cough (55.6%). Histopathologic examination revealed that the rate of intravillous and intervillous calcification, intervillous fibrinoid deposition, hydropic villi and acute lymphocytic villitis, and fetal and maternal thrombi was significantly higher in the COVID-19-positive patients than the control group ( P =0.049, 0.002, 0.049, 0.014, 0.008, 0.001, and 0.014, respectively). There was a significant difference in the CD68 staining of the intravillous and intervillous histiocytes between the groups ( P =0.001). This study showed a significant increase in the intervillous fibrinoid deposition, thrombi formation in the maternal and fetal vascular structures, acute lymphocytic villitis, and an increase of CD68 + stained histiocytes in the intravillous and intervillous spaces in women infected with COVID-19 during the first trimester of pregnancy.

The accuracy of quantifying the degree of hard tissue calcification using an electron probe micro analyzer, micro-focus X-ray computed tomography, and tissue sectioning methods

ObjectivesMicro-focus X-ray computed tomography (μCT) helps evaluate specimens without destroying it. However, its accuracy of quantifying bone mineral density remains to be fully elucidated. We aimed to verify the accuracy of calcification assessed by μCT, by comparing the images of identical specimens obtained via different methods such as μCT and electron probe micro analyzer (EPMA) analyses. MethodsThe maxillae, mandibles, and tibiae of five-week-old male mice were analyzed. Calcification density was analyzed using μCT. The right sides of the specimens were decalcified and processed for Azan staining. The left side of the specimens underwent elemental mapping for Ca, Mg, and P using EPMA. ResultsμCT revealed a significant increase in calcification levels in the following order: enamel, dentin, cortical bone, and trabecular bone. These results reflected the Ca and P levels observed in the EPMA analyses. μCT demonstrated significant differences in the degree of calcification among the enamel tissues or dentin tissues, except for dentin in the maxillary incisors and molars. However, EPMA analysis did not demonstrate significant differences in the Ca and P levels among the same tissue samples. ConclusionsEPMA elemental analysis can be used to measure Ca and P levels for evaluating the calcification rate of hard tissues. Additionally, the study results validate the evaluation of calcification density via μCT. Furthermore, μCT can evaluate even minute differences in calcification rates compared with EPMA analysis.

The effect of central lymph node dissection on the prognosis of cN0 papillary thyroid microcarcinoma: a mid-term follow-up study

BackgroundTo investigate the effect of central lymph node dissection on the prognosis of patients with papillary thyroid microcarcinoma (PTMC) without clinical lymph node metastasis (cN0).MethodsAccording to the inclusion and exclusion criteria, 462 patients with cN0 PTMC underwent surgery in the Second Department of General Surgery, Zhongshan City People’s Hospital from January 1, 2007, to June 31, 2017. They were divided into two groups: the undissection group (262 cases) and the dissection group (170 cases). A comparison was made between the two groups in terms of postoperative complications, recurrences, metastases, etc., as well aslymph node metastasis risk factors in the central region of cN0 PTMC.ResultsThere was no lymphatic leakage or death in all patients after the operation. In the dissection group, 64 cases (37.6%) of central lymph node metastasis were found after the postoperative pathological examination. The undissection group was followed up for (92 ± 28.7) months, and the dissection group was followed up for (86 ± 25.4) months (t=-2.165, P = 0.031). In the two groups, there were no lung metastases, bone metastases, or other distant metastases during the follow-up period. In the undissection group, there were 7 cases, while in the dissection group, there were just 2. Recurrence rates between the two groups did not differ significantly (χ2 = 0.126, P = 0.169); Similarly, disease-free survival curves did not differ significantly (χ2 = 2.565, P = 0.708). Hypoparathyroidism and Hypocalcemia also had no difference between the group. In comparison to the undissection group, the capsular invasion rate (P = 0.026), calcification rate(P < 0.001) incidence of postoperative hoarseness (P = 0.017), and hand and foot numbness rate (P < 0.001) were all considerably greater in the dissection group. Multivariate research revealed that capsular invasion (OR = 9.42, P = 0.002), multifocal (OR = 24.57, P < 0.001), and tumor diameter > 5 mm (OR = 5.46, P = 0.019) were the independent risk factors for central lymph node metastasis in cN0 PTMC.ConclusionsThyroidectomy alone is safe for cN0 PTMC, but longer-term follow-up is still required for changes in central lymph nodes. For cN0 PTMC patients with tumor diameter > 5 mm, multifocal, and capsular invasion, central lymph node metastasis is more likely to occur. Comprehensive evaluation and individualized and precise treatment are essential.