Evaluating the novel parameters for assessing the LAA function and thrombus formation with nonvalvular atrial fibrillation.

The dysfunction of left atrial appendage (LAA) is prone to form thrombus when atrial fibrillation (AF) sustained more than 48 h. Traditional 2D-TEE (transesophageal echocardiography) can not accurate evaluate the function of LAA. The purpose of this study is to analyze the relationship of LAA function parameters and thrombus formation in patients with non-valvular atrial fibrillation (NVAF) by real-time three-dimensional transesophageal echocardiography (RT-3D-TEE). High risk patients can be identified according to the characteristics of ultrasonic index in patients with left atrial appendage thrombosis, which has important clinical value and significance in the risk assessment, guiding treatment and judging prognosis. We examined the relationship between the echocardiographic parameters of LAA function and the incidence of thrombus in 102 NVAF patients. They underwent RT-3D-TEE and left atrial appendage thrombus (LAAT)/severe spontaneous echocardiographic contrast (SSEC) was found in 67 patients (thrombus group) but absent in the remaining 35 patients (non-thrombus group). After measured by QLAB software, the LAA functional parameters were significantly associated with LAAT/SEC formation. Univariate analysis indicated that AF time, LAD, LVEF, LAA-OAmax, LAAVmax, LAAVI and LAAEF demonstrated a positive association (P < 0.05). However, logistic regression analysis identified that AF time (OR:1.73, P < 0.05)、LAAEF (OR:4.09, P < 0.01)and LAAVI (OR:3.28, P < 0.01) were independent predictors of LAAT/SSEC. In patients with nonvalvular atrial fibrillation, echocardiographic parameters of LAA function are significantly associated with LAAT/SSEC.

Alteration in Cngb1 Expression upon Maternal Immune Activation in a Mouse Model and Its Possible Association with Schizophrenia Susceptibility

Objective@#The cyclic nucleotide-gated channel (Cng) regulates synaptic efficacy in brain neurons by modulating Ca2＋ levels in response to changes in cyclic nucleotide concentrations. This study investigated whether the expression of Cng channel, cyclic nucleotide-gated channel subunit beta 1 (Cngb1) exhibited any relationship with the pathophysiology of schizophrenia in an animal model and whether genetic polymorphisms of the human gene were associated with the progression of schizophrenia in a Korean population. @*Methods@#We investigated whether Cngb1 expression was related to psychiatric disorders in a mouse model of schizophrenia induced by maternal immune activation. A case-control study was conducted of 275 schizophrenia patients and 410 controls with single-nucleotide polymorphisms (SNPs) in the 5′-near region of CNGB1. @*Results@#Cngb1 expression was decreased in the prefrontal cortex in the mouse model. Furthermore, the genotype frequency of a SNP (rs3756314) of CNGB1 was associated with the risk of schizophrenia. @*Conclusion@#Our results suggest that CNGB1 might be associated with schizophrenia susceptibility and maternal immune activation. Consequently, it is hypothesized that CNGB1 may be involved in the pathophysiology of schizophrenia.

Identification of novel bioactive molecules from garlic bulbs: A special effort to determine the anticancer potential against lung cancer with targeted drugs.

Garlic (Allium sativum L.), is a predominant spice, which is used as an herbal medicine and flavoring agent, since ancient times. It has a rich source of various secondary metabolites such as flavonoids, terpenoids and alkaloids, which have various pharmacological properties. Garlic is used in the treatment of various ailments such as cancer, diabetes and cardiovascular diseases. The present study aims to explore the plausible mechanisms of the selected phytocompounds as potential inhibitors against the known drug targets of non-small-cell lung cancer (NSCLC). The phytocompounds of garlic were identified by gas chromatography-mass spectrometry (GC-MS) technique. Subsequently, the identified phytocompounds were subjected to molecular docking to predict the binding with the drug targets, epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) and group IIa secretory phospholipase A2 (sPLA2-IIA). Molecular dynamics is used to predict the stability of the identified phytocompounds against NSCLC drug targets by refining the intermolecular interactions formed between them. Among the 12 phytocompounds of garlic, three compounds[1,4-dimethyl-7-(1-methylethyl)-2-azulenyl]phenylmethanone, 2,4-bis(1-phenylethyl)-phenol and 4,5-2 h-oxazole-5-one,4-[3,5-di-t-butyl-4-methoxyphenyl] methylene-2-phenyl were identified as potential inhibitors, which might be suitable for targeting the different clinical forms of EGFR and dual inhibition of the studied drug targets to combat NSCLC. The result of this study suggest that these identified phytocompounds from garlic would serve as promising leads for the development of lead molecules to design new multi-targeting drugs to address the different clinical forms of NSCLC.

In-vitro phytochemical and pharmacological bio-efficacy studies on Azadirachta indica A. Juss and Melia azedarach Linn for anticancer activity.

In this study, phyto-constituents, anti-bacterial and anticancer activity of Azadirachta indica A. Juss and Melia azedarach Linn was analyzed. High Performance Liquid Chromatography (HPLC) and Thin Layer Chromatography (TLC) fingerprint profile of methanol extract of A. indica and M. azedarach was carried out. The present findings showed the presence of phytochemicals such as, steroids, alkaloids, phenols, flavonoids, saponins, tannins, anthraquinone and aminoacids in A. indica and M. azedarach extracts. HPLC profiling of methanolic extract of A. indica and M. azaderach revealed eleven and ten fractions of compounds were visualized in the form of peak. In TLC methanolic extract of A. indica was separated by eight distinct phenolic and three steroidal bands and M. azaderach showed sixteen distinct phenolic and three different steroidal bands. In antibacterial activity, Among the various extracts 50 µg/ml methanolic extracts of A. indica showed high activity against K. pneumoniae (14 mm) and M. azedarach showed high activity against S. aureus (15 mm). The results suggest that the crude methanolic extracts of A. indica and M. azedarach possess significant phytochemical properties compared to other extracts and hence the phytochemicals of M. azedarach and A. indica can be exploited for plant based anticancer and antimicrobial agents in the near future.

Death by Nitrite Intoxication: Report of 14 Cases / 대한법의학회지

Sodium nitrite intoxication is a primary cause of severe methemoglobinemia, which may be fatal. In the past, nitrite-related deaths were rare, but cases of suicide with nitrite have been increasing in number in recent years. We analyzed 14 cases of fatal nitrite intoxication from January 2013 to February 2019. There was a different trend between the cases from the past and those from recent years. The former consisted of older individuals who ingested nitrite accidentally or intentionally, while the latter comprised younger individuals who used nitrite mostly for suicide. Most individuals showed dark purple or dark brown lividity and cherry-pink discoloration of the muscles. Postmortem methemoglobin levels, which were analyzed in 5 cases, were 30%-49%. Most nitrite and nitrate concentrations showed the highest concentration in the stomach contents, and it showed that the nitrite was converted into nitrate in the blood. To conclude, methemoglobin tests using a portable oximeter and quantitative tests of nitrite and nitrate, as well as a thorough investigation of the case and scene may help determine the cause of death.

Effect of Depression on Pulmonary Symptoms and Quality of Life in Patients with Chronic Obstructive Pulmonary Disease / 신경정신의학

OBJECTIVES@#Depression is a common comorbid condition in patients with chronic obstructive pulmonary disease (COPD) and has a higher prevalence than the general population. On the other hand, studies on the incidence of depression and quality of life in COPD patients often depend on a simple self-report questionnaire rather than a psychiatrist's clinical assessment. Starting with accurately diagnosing depression, the purpose of this study was to evaluate the factors related to depression as well as how depression influences the quality of life.@*METHODS@#The study included 30 patients diagnosed with COPD. All the patients were interviewed for a diagnosis of depression by a psychiatrist. They were divided into two groups: with and without depression. For dyspnea, the modified Medical Research Council (mMRC) scale was used to evaluate how it affected daily life. Short-Form Health Survey 36 and COPD assessment test (CAT) were used to assess the quality of life.@*RESULTS@#The degree of COPD and respiratory symptoms were related, but the severity of COPD did not influence the quality of life. In the presence of depression, mMRC and CAT were higher, whereas PCS and MCS were lower than in those without depression. Patients with depression suffered more from dyspnea and had a lower quality of life.@*CONCLUSION@#This study suggests that the degree of COPD was not related to depression. With depression, however, it led to the aggravation of dyspnea and a deteriorated quality of life. Combined treatment is essential to improving the patients' general well-being.

Influence of clozapine on neurodevelopmental protein expression and behavioral patterns in animal model of psychiatric disorder induced by low-level of lead

Exposure to lead during pregnancy is a risk factor for the development of psychiatric disorders in the offspring. In this study, we investigated whether exposure to low levels of lead acetate (0.2%) in drinking water during pregnancy and lactation causes behavioral impairment and affects the expression of proteins associated with neurodevelopment. Lead exposure altered several parameters in rat offspring compared with those unexposed in open-field, social interaction, and pre-pulse inhibition tests. These parameters were restored to normal levels after clozapine treatment. Western blot and immunohistochemical analyses of the hippocampus revealed that several neurodevelopmental proteins were downregulated in lead-exposed rats. The expression was normalized after clozapine treatment (5 mg/kg/day, postnatal day 35–56). These findings demonstrate that downregulation of several proteins in lead-exposed rats affected subsequent behavioral changes. Our results suggest that lead exposure in early life may induce psychiatric disorders and treatment with antipsychotics such as clozapine may reduce their incidence.

Reliability and Validity of the Mental Health Questionnaire for Adult / 신경정신의학

OBJECTIVES: The aim of this study was to develop a Mental Health Questionnaire for Adults (MHQ-A) and investigate its validity and reliability. METHODS: A 73-item questionnaire was developed or selected by seven psychiatrists and a clinical psychologist. The questionnaire was administered to 351 subjects in Seoul and Gyeonggi area. The construct validity was investigated by performing principal component analysis, and the reliability was assessed in terms of the internal consistency using Cronbach's alpha. RESULTS: Principal component analysis revealed 15 factors underlying the psychiatric disorder and symptom category. Taken together, these 15 factors accounted for 64.023% of the common variance. Cronbach's alpha was high, indicating that the reliability of the questionnaire was satisfactory. Every category showed a positive correlation with most psychological measures. CONCLUSION: These results indicate that the MHQ-A is a reliable and valid scale for assessing psychiatric disorders. Although there were many limitations, the present study has significance as the basis of future research.

Reliability and Validity of the Brief Schema Questionnaire for Adult / 신경정신의학

OBJECTIVES: The aim of this study was to develop a brief schema questionnaire for adults (BSQ-A) and investigate its validity and reliability. METHODS: A 36-item questionnaire was developed or selected by six psychiatrists. The questionnaire was administered to 209 subjects in Seoul and Gyeonggi area. The construct validity was investigated by performing principal component analysis, and the reliability was assessed in terms of the internal consistency using Cronbach's alpha. RESULTS: The principal component analysis revealed 18 factors underlying 18 early maladaptive schemas (EMSs). These 18 factors accounted for 87.488% of the common variance. The Cronbach's alpha was high, indicating that the reliability of the questionnaire was satisfactory. Every schema showed a positive correlation with most psychological measures. CONCLUSION: The results indicate that the BSQ-A is a reliable and valid scale for assessing EMSs. Although there are many limitations, the present study is expected to form the basis of future research.

Worker Safety in the Rare Earth Elements Recycling Process From the Review of Toxicity and Issues

Although the rare earth elements (REEs) recycling industry is expected to increase worldwide in high-tech industry, regulations for worker safety have yet to be established. This study was conducted to understand the potential hazard/risk of REE recycling and to support the establishment of regulations or standards. We review the extensive literature on the toxicology, occupational safety, and health issues, and epidemiological surveys related to the REEs, and propose suitable management measures. REE recycling has four key steps such as collection, dismantling, separation, and processing. In these processes, hazardous substances, such as REEs-containing dust, metals, and chemicals, were used or occurred, including the risk of ignition and explosion, and the workers can be easily exposed to them. In addition, skin irritation and toxicities for respiratory, nervous, and cardiovascular systems with the liver toxicity were reported; however, more supplementary data are needed, owing to incompleteness. Therefore, monitoring systems concerning health, environmental impacts, and safety need to be established, based on additional research studies. It is also necessary to develop innovative and environment-friendly recycling technologies, analytical methods, and biomarkers with government support. Through these efforts, the occupational safety and health status will be improved, along with the establishment of advanced REE recycling industry.

Effects of 1,25-dihydroxyvitamin D₃ on the differentiation of MC3T3-E1 osteoblast-like cells

PURPOSE: The purpose of this study was to evaluate the effects of 1,25-dihydroxyvitamin D₃ on the proliferation, differentiation, and matrix mineralization of MC3T3-E1 osteoblast-like cells in vitro. METHODS: MC3T3-E1 osteoblastic cells and 1,25-dihydroxyvitamin D₃ were prepared. Cytotoxic effects and osteogenic differentiation were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, alkaline phosphatase (ALP) activity assay, ALP staining, alizarin red S staining, and reverse transcription-polymerase chain reaction (RT-PCR) for osteogenic differentiation markers such as ALP, collagen type I (Col-I), osteocalcin (OCN), vitamin D receptor (VDR), and glyceraldehyde 3-phosphate dehydrogenase. RESULTS: The MTT assay showed that 1,25-dihydroxyvitamin D₃ did not inhibit cell growth and that the rate of cell proliferation was higher than in the positive control group at all concentrations. ALP activity was also higher than in the positive control group at low concentrations of 1,25-dihydroxyvitamin D₃ (10−10, 10−12, and 10−14 M). RT-PCR showed that the gene expression levels of ALP, Col-I, OCN, and vitamin D receptor (VDR) were higher at a low concentration of 1,25-dihydroxyvitamin D₃ (10−12 M). Alizarin red S staining after treatment with 1,25-dihydroxyvitamin D₃ (10−12 M) showed no significant differences in the overall degree of calcification. In contrast to the positive control group, formation of bone nodules was induced in the early stages of cell differentiation. CONCLUSIONS: We suggest that 1,25-dihydroxyvitamin D₃ positively affects cell differentiation and matrix mineralization. Therefore, it may function as a stimulating factor in osteoblastic bone formation and can be used as an additive in bone regeneration treatment.

Effects of platelet-rich plasma on tooth replantation in dogs: a histologic and histomorphometric analysis

PURPOSE: The purpose of this study was to evaluate the effects of platelet-rich plasma (PRP) on periodontal healing of replanted root surfaces in dogs histologically and histomorphometrically. METHODS: A total of 36 roots of mandibular incisors and premolars from 6 mongrel dogs were used. The roots were randomly divided into 3 groups: 1) a positive control group (n=12), in which the periodontal ligament (PDL) and cementum were retained and the roots were soaked in saline; 2) a negative control group (n=12), in which the PDL and cementum were removed and the roots were soaked in saline; and 3) an experimental group (n=12), in which the PDL and cementum were removed and the roots were soaked in PRP. After soaking the root surfaces, the extracted roots were replanted into the extraction sockets. The roots were covered using a coronally repositioned flap RESULTS: Histologically, irregular-thickness PDL-like and cementum-like tissues were observed in the 4-week experimental group and the positive control group. PDL-like tissue and cementum-like tissue with a more uniform thickness were observed at 8 weeks. In the negative control group, PDL-like tissue and cementum-like tissue were rarely found, and root resorption and ankylosis were observed. In the cross-sectional histomorphometric analysis, the experimental group demonstrated a higher rate of formation of cementum-like tissue and a lower tooth ankylosis rate than the positive and negative control groups at 4 and 8 weeks. Although there was a significant difference in the tooth ankylosis rate and the formation of cementum-like tissue across the 3 groups (P 0.017). CONCLUSIONS: Applying PRP to root surfaces during tooth replantation in dogs can reduce tooth ankylosis and increase PDL-like and cementum-like tissue formation.

CT-Guided Percutaneous Transthoracic Needle Biopsy Using the Additional Laser Guidance System by a Pulmonologist with 2 Years of Experience in CT-Guided Percutaneous Transthoracic Needle Biopsy / 결핵및호흡기질환

BACKGROUND: We developed an additional laser guidance system to improve the efficacy and safety of conventional computed tomography (CT)–guided percutaneous transthoracic needle biopsy (PTNB), and we conducted this study to evaluate the efficacy and safety of our system. METHODS: We retrospectively analyzed the medical records of 244 patients who underwent CT-guided PTNB using our additional laser guidance system from July 1, 2015, to January 20, 2016. RESULTS: There were nine false-negative results among the 238 total cases. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of our system for diagnosing malignancy were 94.4% (152/161), 100% (77/77), 100% (152/152), 89.5% (77/86), and 96.2% (229/238), respectively. The results of univariate analysis showed that the risk factors for a false-negative result were male sex (p=0.029), a final diagnosis of malignancy (p=0.033), a lesion in the lower lobe (p=0.035), shorter distance from the skin to the target lesion (p=0.003), and shorter distance from the pleura to the target lesion (p=0.006). The overall complication rate was 30.5% (74/243). Pneumothorax, hemoptysis, and hemothorax occurred in 21.8% (53/243), 9.1% (22/243), and 1.6% (4/243) of cases, respectively. CONCLUSION: The additional laser guidance system might be a highly economical and efficient method to improve the diagnostic efficacy and safety of conventional CT-guided PTNB even if performed by inexperienced pulmonologists.

Patient Safety Awareness and Emergency Response Ability Perceived by Nursing Homes and Home Visiting Caregivers / 한국간호교육학회지

PURPOSE: The purpose of this study was to identify patient safety awareness and emergency response ability and affecting factors perceived by nursing homes and home visiting caregivers. METHODS: This study was a descriptive study that conveniently extracts nursing caregivers who care for elderly patients in S and G provinces, Korea. Data collection was done by structural questionnaires from April to May 2018. A total of 204 responses consisting of 103 nursing homes and 101 home visiting caregivers were used for data analysis in SPSS Win 22.0. RESULTS: Patient safety awareness and emergency response ability of nursing homes caregivers with each 4.24±0.50, 74.26±09.57 was each higher than that of the home visiting caregivers with 3.68±0.49, 68.02±12.12 (p < .001). The affecting factors of the patient safety awareness were working place, safety education, and daily average working hours with 12 or more (F = 27.30, p < .001) and that of emergency response ability were number of patients per personnel with 9 or more and emergency situation experience (F=14.00, p < .001). CONCLUSION: These results suggest that it is necessary to develop a safety education program that can share indirectly experience emergency situations that occur on the job site.

Effects of Tianeptine on Adult Rats Following Prenatal Stress

OBJECTIVE: Exposing a pregnant female to stress during the critical period of embryonic fetal brain development increases the risk of psychiatric disorders in the offspring. The objective of this study was to investigate the effect of antidepressant tianeptine on prenatally stressed (PNS) rats. METHODS: In this study, a repeated variable stress paradigm was applied to pregnant rats during the last week of gestation. To investigate the effects of antidepressant tianeptine on PNS rats, behavioral and protein expression analyses were performed. Forced swim test, open field test, and social interaction test were performed to determine changes in PNS rats compared to non-stressed offspring. Haloperidol was used as a positive control as an antipsychotic drug based on previous studies. RESULTS: Behavioral changes were restored after treatment with tianeptine or haloperidol. Western blot and immunohistochemical analyses of the prefrontal cortex revealed downregulation of several neurodevelopmental proteins in PNS rats. After treatment with tianeptine or haloperidol, their expression levels were increased. CONCLUSION: Downregulation of several proteins in PNS rats might have caused subsequent behavioral changes in PNS rats. After tianeptine or haloperidol treatment, behavioral changes in PNS rats were restored. Therefore, tianeptine might decrease incidence of prenatal stress related-psychiatric disorders such as depression and schizophrenia.

Effects of tianeptine on symptoms of fibromyalgia via BDNF signaling in a fibromyalgia animal model

Previous reports have suggested that physical and psychological stresses may trigger fibromyalgia (FM). Stress is an important risk factor in the development of depression and memory impairments. Antidepressants have been used to prevent stress-induced abnormal pain sensation. Among various antidepressants, tianeptine has been reported to be able to prevent neurodegeneration due to chronic stress and reverse decreases in hippocampal volume. To assess the possible effect of tianeptine on FM symptoms, we constructed a FM animal model induced by restraint stress with intermittent cold stress. All mice underwent nociceptive assays using electronic von Frey anesthesiometer and Hargreaves equipment. To assess the relationship between tianeptine and expression levels of brain-derived neurotrophic factor (BDNF), cAMP response element-binding protein (CREB), and phosphorylated cAMP response element-binding protein (p-CREB), western blotting and immunohistochemistry analyses were performed. In behavioral analysis, nociception tests showed that pain threshold was significantly decreased in the FM group compared to that in the control group. Western blot and immunohistochemical analyses of medial prefrontal cortex (mPFC) and hippocampus showed downregulation of BDNF and p-CREB proteins in the FM group compared to the control group. However, tianeptine recovered these changes in behavioral tests and protein level. Therefore, this FM animal model might be useful for investigating mechanisms linking BDNF-CREB pathway and pain. Our results suggest that tianeptine might potentially have therapeutic efficacy for FM.

Acetaminophen Induced Hepatotoxicity in Wistar Rats--A Proteomic Approach.

Understanding the mechanism of chemical toxicity, which is essential for cross-species and dose extrapolations, is a major challenge for toxicologists. Standard mechanistic studies in animals for examining the toxic and pathological changes associated with the chemical exposure have often been limited to the single end point or pathways. Toxicoproteomics represents a potential aid to the toxicologist to understand the multiple pathways involved in the mechanism of toxicity and also determine the biomarkers that are possible to predictive the toxicological response. We performed an acute toxicity study in Wistar rats with the prototype liver toxin; the acetaminophen (APAP) effects on protein profiles in the liver and its correlation with the plasma biochemical markers for liver injury were analyzed. Three separate groups--control, nontoxic (150 mg/kg) and toxic dose (1500 mg/kg) of APAP--were studied. The proteins extracted from the liver were separated by 2-DE and analyzed by MALDI-TOF. The differential proteins in the gels were analyzed by BIORAD's PDQuest software and identified by feeding the peptide mass fingerprint data to various public domain programs like Mascot and MS-Fit. The identified proteins in toxicity-induced rats were classified based on their putative protein functions, which are oxidative stress (31%), immunity (14%), neurological related (12%) and transporter proteins (2%), whereas in non-toxic dose-induced rats they were oxidative stress (9%), immunity (6%), neurological (14%) and transporter proteins (9%). It is evident that the percentages of oxidative stress and immunity-related proteins were up-regulated in toxicity-induced rats as compared with nontoxic and control rats. Some of the liver drug metabolizing and detoxifying enzymes were depleted under toxic conditions compared with non-toxic rats. Several other proteins were identified as a first step in developing an in-house rodent liver toxicoproteomics database.

The association between radiographic embrasure morphology and interdental papilla reconstruction using injectable hyaluronic acid gel

PURPOSE: The purpose of this study was to evaluate the clinical efficacy of enhancing deficient interdental papilla with hyaluronic acid gel injection by assessing the radiographic anatomical factors affecting the reconstruction of the interdental papilla. METHODS: Fifty-seven treated sites from 13 patients (6 males and 7 females) were included. Patients had papillary deficiency in the upper anterior area. Prior to treatment, photographic and periapical radiographic standardization devices were designed for each patient. A 30-gauge needle was used with an injection-assistance device to inject a hyaluronic acid gel to the involved papilla. This treatment was repeated up to 5 times every 3 weeks. Patients were followed up for 6 months after the initial gel application. Clinical photographic measurements of the black triangle area (BTA), height (BTH), and width (BTW) and periapical radiographic measurements of the contact point and the bone crest (CP-BC) and the interproximal distance between roots (IDR) were undertaken using computer software. The interdental papilla reconstruction rate (IPRR) was calculated to determine the percentage change of BTA between the initial and final examination and the association between radiographic factors and the reconstruction of the interdental papilla by means of injectable hyaluronic acid gel were evaluated. RESULTS: All sites showed improvement between treatment examinations. Thirty-six sites had complete interdental papilla reconstruction and 21 sites showed improvement ranging from 19% to 96%. The CP-BC correlated with the IPRR. More specifically, when the CP-BC reached 6 mm, virtually complete interdental papilla reconstruction via injectable hyaluronic acid gel was achieved. CONCLUSIONS: These results suggest that the CP-BC is closely related to the efficacy of hyaluronic acid gel injection for interdental papilla reconstruction.

Effect of fibroblast growth factor on injured periodontal ligament and cementum after tooth replantation in dogs

PURPOSE: The purpose of this animal study was to perform a histological and histomorphometric analysis in order to elucidate the effect of fibroblast growth factor-2 (FGF-2) on injured periodontal ligament (PDL) and cementum after tooth replantation in dogs. METHODS: The roots of 36 mandibular premolars from six mongrel dogs were used in this study. The roots were randomly divided into three groups: (1) a positive control group (n=12), in which the PDL was retained; (2) a negative control group (n=12), in which the PDL and the cementum between the notches were removed; and (3) an experimental group (n=12), in which the PDL and the cementum between the notches were removed and the roots were soaked in an FGF-2 solution (30 microg/0.1 mL). After treating the root surfaces, the extracted roots were replanted into extraction sockets. The animals were sacrificed four and eight weeks after surgery for histologic and histomorphometric evaluation. RESULTS: At four and eight weeks, normal PDLs covered the roots in the positive control group. In the negative control group, most replanted roots showed signs of replacement resorption. In the experimental group, new PDL-like tissue and cementum-like tissue were observed to partially occupy the region between the root surfaces and the newly formed bone. Histomorphometric analysis showed that the mean length of the newly formed cementum-like tissue on the roots treated with FGF-2 was significantly greater than that of the tissue on the roots in the negative control group (four weeks, P=0.008; eight weeks, P=0.042). However, no significant differences were observed between the roots treated with FGF-2 and the negative control roots with respect to newly formed PDL-like tissue. CONCLUSIONS: The results of this study suggest that use of FGF-2 on injured root surfaces promotes cementogenesis after tooth replacement in dogs.