Medication-related osteonecrosis of the lower jaw without osteolysis on computed tomography images.

INTRODUCTION: Surgery is the standard treatment for medication-related osteonecrosis of the jaw (MRONJ). This study reviewed patients with mandibular MRONJ who underwent surgical treatment, and in particular the characteristics of non-osteolytic MRONJ with no evidence of osteolysis on CT were described. MATERIALS AND METHODS: We conducted a retrospective study of patients with mandibular MRONJ who underwent surgery between January 2016 and September 2022. Various clinical and imaging factors regarding treatment outcomes were investigated and analyzed. Additionally, the disease course of non-osteolytic MRONJ was examined in detail. RESULTS: This study included 55 patients (66 surgeries) with a mean age of 74.7. The primary disease was osteoporosis (24 patients) and malignancy (31 patients); the type of antiresorptive agent was bisphosphonate (BP) in 21 patients and denosumab (DMB) in 26. BP was initially administered; however, it was changed to DMB in eight patients. Preoperatively, the cumulative cure rates for all 66 surgeries were 72.8% at 1 year and 77.3% at 2 years. Cure rates were significantly lower in patients with malignancy, those without osteolysis, and those who underwent sequestrum removal or marginal mandibulectomy than those with osteoporosis, osteolysis, and segmental mandibulectomy. Non-osteolytic MRONJ was observed in eight patients, all with malignancy and receiving high-dose DMB. Only two patients were cured after the initial surgery, and most patients ultimately underwent segmental mandibulectomy. CONCLUSIONS: Surgical treatment yielded good treatment outcomes in most patients with mandibular MRONJ; however, the cure rate was lower in patients with malignancy who showed no osteolysis on CT images.

Structural basis for proteolytic processing of Aspergillus sojae α-glucosidase L with strong transglucosylation activity.

An α-glucosidase from Aspergillus sojae, AsojAgdL, exhibits strong transglucosylation activity to produce α-1,6-glucosidic linkages. The most remarkable structural feature of AsojAgdL is that residues 457-560 of AsojAgdL (designated the NC sequence) is not conserved in other glycoside hydrolase family 31 enzymes, and part of this NC sequence is proteolytically cleaved during its maturation. In this study, the enzyme was expressed in Pichia pastoris, and electrophoretic analysis indicated that the recombinant enzyme, rAsojAgdL, consisted of two polypeptide chains, as observed in the case of the enzyme produced in an Aspergillus strain. The crystal structure of rAsojAgdL was determined in complex with the substrate analog trehalose. Electron density corresponding to residues 496-515 of the NC sequence was not seen, and there were no α-helices or ß-strands except for a short α-helix in the structures of residues 457-495 and residues 516-560, both of which belong to the NC sequence. The residues 457-495 and the residues 516-560 both formed extra components of the catalytic domain. The residues 457-495 constituted the entrance of the catalytic pocket of rAsojAgdL, and Gly467, Asp468, Pro469, and Pro470 in the NC sequence were located within 4 Å of Trp400, a key residue involved in binding of the substrate. The results suggest that the proteolytic processing of the NC sequence is related to the formation of the catalytic pocket of AsojAgdL.

Association between dental extraction after radiotherapy and osteoradionecrosis: A multi-centre retrospective study.

OBJECTIVE: Radiotherapy (RT) carries a substantial risk for the development of osteoradionecrosis (ORN) of the jaw. This study was performed to investigate the relationship between dental extractions after RT and the development of ORN. MATERIAL AND METHODS: Thirty-two patients with head and neck cancer who underwent tooth extraction after RT were investigated for correlations between the development of ORN and various factors. RESULTS: Postextraction ORN was diagnosed in 12 (12.1%) teeth of 9 patients. The RT dose against the site of tooth extraction was 62.0 and 37.4 Gy in the ORN and Non-ORN groups, respectively (p < .001). The duration from RT to tooth extraction was 41.2 and 28.2 months in the ORN and Non-ORN groups, respectively (p = .025). Tooth extraction was significantly associated with ORN in patients with a high RT dose against the site (odds ratio = 1.231) and a longer duration of time from RT (odds ratio = 1.084). CONCLUSIONS: Extraction of non-restorable teeth and those with a poor prognosis should not necessarily be postponed even when patients are undergoing RT. However, clinicians should pay special attention to postoperative management after tooth extraction in patients with a high RT dose and longer time from RT.

Development of a Novel Real-Time Polymerase Chain Reaction Assay to Detect Escherichia albertii in Chicken Meat.

Escherichia albertii is an emerging enteropathogen. Several foodborne outbreaks of E. albertii have been reported in Japan; however, foods associated with most outbreaks remain unidentified. Therefore, polymerase chain reaction (PCR) assays detecting E. albertii specifically and sensitively are required. Primers and probe for real-time PCR assays targeting E. albertii-specific gene (EA-rtPCR) was designed. With 74 strains, including 43 E. albertii strains and several of its close relatives, EA-rtPCR specifically amplified E. albertii; therefore, the sensitivity of EA-rtPCR was then evaluated. The detection limits were 2.8 and 2.0-3.2 log colony-forming unit (CFU)/mL for E. albertii culture and enriched chicken culture inoculated with the pathogen, respectively. In addition, E. albertii was detected from 25 g of chicken meat inoculated with 0.1 log CFU of the pathogen by EA-rtPCR. The detection of E. albertii from chicken meat by EA-rtPCR was also evaluated by comparing with the nested-PCR assay, and 28 retail chicken meat and 193 dissected body parts from 21 chicken carcass were tested. One and three chicken meat were positive in the nested-PCR assay and EA-rtPCR, respectively. Fourteen carcasses had at least one body part that was positive for EA-rtPCR, and 36 and 48 samples were positive for the nested-PCR assay and EA-rtPCR, respectively. A total of 37 strains of E. albertii were isolated from seven PCR-positive samples obtained from six chicken carcass. All E. albertii isolates harbored eae gene, and were classified as E. albertii O-genotype (EAOg)3 or EAOg4 by EAO-genotyping. The EA-rtPCR developed in this study has potential to improve E. albertii detection in food and advance research on E. albertii infection.

Effect of periosteal reaction in medication-related osteonecrosis of the jaw on treatment outcome after surgery.

INTRODUCTION: Surgical treatment in patients with medication-related osteonecrosis of the jaw (MRONJ) is superior to conservative treatment. However, treatment outcome in patients with periosteal reaction (PR) was significantly poorer than that of those without PR. The purpose of this retrospective study was to analyze the pathophysiology and clinical significance of PR in MRONJ. MATERIALS AND METHODS: Out of 181 patients with MRONJ undergoing surgery, 38 patients with PR were enrolled in the study. CT examinations, histological examinations, and bacteriological examinations using real-time polymerase chain reaction were performed, and the relationship among the opted surgical method, CT findings, and treatment outcome was investigated. RESULTS: The pattern of PR was classified into three types: type 1, new bone is formed parallel to the mandible, and no gap was evident between the mandible and new bone; type 2, new bone is formed parallel to the mandible, and a gap was evident between them; type 3, an irregular shape. Histological examinations revealed inflammatory tissue in the area visualized as a gap on CT. Bacteriological examination showed the presence of bacteria in the type 2 or type 3 PR. Complete cure was observed in 21 of 38 (55.3%) patients, which was lower than the cure rate of 73.4% in 143 patients without PR. The cure rate was significantly lower in cases with type 3 PR or with persistent osteolysis. CONCLUSIONS: It seems that complete resection of both osteolytic area and type 3 PR is necessary to obtain complete healing in patients undergoing marginal mandibulectomy.

Periosteal reaction of medication-related osteonecrosis of the jaw (MRONJ): clinical significance and changes during conservative therapy.

PURPOSE: We previously reported that the periosteal reaction (PR) in medication-related osteonecrosis of the jaw (MRONJ) is a poor prognostic factor in surgical cases, but it is not clear how PR changes during conservative therapy. The purpose of this retrospective study was to compare computed tomography (CT) findings at the first visit and during follow-up visits in MRONJ patients subjected to conservative therapy and to investigate factors associated with the exacerbation of PR during conservative therapy. METHODS: Sixteen patients with MRONJ of the lower jaw who underwent conservative therapy and experienced a PR on CT images at the first visit and underwent CT examination again after 6 months or more were enrolled in the study. Clinical features and CT findings (extent of osteolytic lesion, extent of PR, type of PR, and changes during conservative treatment) were investigated. RESULTS: On the second CT scan, the osteolytic lesion improved in 4 patients, had not changed in 5, and deteriorated in 7, whereas the PR improved in 5 patients, had not changed in 4, and deteriorated in 7 patients. PR was significantly deteriorated in patients who continued to receive antiresorptive agents during conservative treatment and in patients with deteriorated osteolytic lesions. CONCLUSION: PR in MRONJ often expands during conservative therapy and the PR type progresses from the attached type to the gap type, and the irregular type, but discontinuation of antiresorptive agent may improve PR as well as osteolytic lesions.

Drug holiday clinical relevance verification for antiresorptive agents in medication-related osteonecrosis cases of the jaw.

Treatment strategies of medication-related osteonecrosis of the jaw (MRONJ) are controversial. Recently, surgical treatment has been reported as superior to nonsurgical treatment, but the contribution discontinued antiresorptive agent use during MRONJ treatment remains unclear. This study aimed to evaluate the efficacy of drug holidays and treatment strategies in MRONJ cases. Four-hundred and twenty-seven patients with MRONJ treated at nine hospitals from 2009 to 2017 were included in this multicenter retrospective study. Multivariate Cox regression analysis showed that the primary disease (osteoporosis or malignant tumor), diabetes, serum albumin, and treatment method (surgical or nonsurgical) were significantly correlated with the cure rate. The cumulative 1-year cure rates in the surgical and nonsurgical treatment groups were 64.7% and 18.2%, respectively. However, discontinuing antiresorptive agents did not influence the treatment outcome in the cohort overall, or in 230 patients after performing propensity score matching among the discontinuation and continuation groups. When stratifying by treatment method, antiresorptive agent discontinuation significantly increased the cure rate in patients with osteoporosis who underwent nonsurgical treatment. In patients with malignant tumors undergoing nonsurgical therapy, discontinuing the antiresorptive agent was associated with a better treatment outcome, but not with statistical significance. In contrast, drug holidays showed no effect on improving outcomes in patients with both osteoporosis and malignant tumors who underwent surgical therapy. Thus, regardless of the primary disease, discontinuing antiresorptive agents during treatment for MRONJ may not be necessary and may be helpful in some cases. Future prospective trials should examine this question further.

Factors associated with severe oral mucositis and candidiasis in patients undergoing radiotherapy for oral and oropharyngeal carcinomas: a retrospective multicenter study of 326 patients.

PURPOSE: The present retrospective multicenter study intended to investigate the factors associated with severe oral mucositis and candidiasis in patients undergoing radiotherapy for oral and oropharyngeal carcinomas. METHODS: A total of 326 patients who underwent radiotherapy for oral and oropharyngeal cancers were enrolled in the study. The patients' age, sex, body mass index, primary site, diabetes, serum albumin, creatinine, hemoglobin, leukocyte and lymphocyte, concurrent cisplatin or cetuximab, method of radiation, total radiation dose, feeding route, use of spacers, pilocarpine hydrochloride, and corticosteroid ointment were examined, and the associations of each variable with oral mucositis and candidiasis were analyzed by multivariate Cox regression analysis. RESULTS: Grade 3 oral mucositis occurred in 136 (41.7%) patients. Male sex, oropharyngeal cancer, low hemoglobin levels, low leukocytes or lymphocytes, concurrent cisplatin or cetuximab, and oral feeding were found to be significantly associated with a higher incidence of severe oral mucositis. Oral candidiasis occurred in 101 (31.0%) patients. Oropharyngeal cancer, low leukocyte count, and oral mucositis of grade 2 or higher were found to be significantly associated with a higher incidence of oral candidiasis. The use of a topical steroid ointment was not found to be a risk factor for oral candidiasis. CONCLUSIONS: The present retrospective study demonstrated that certain factors may predispose patients with oral and oropharyngeal cancers receiving radiotherapy to develop severe oral mucositis and oral candidiasis. A preventive strategy for severe oral mucositis needs to be established in the future for high-risk cases.

Clinical significance of periosteal reaction as a predictive factor for treatment outcome of medication-related osteonecrosis of the jaw.

Regarding treatment strategies for medication-related osteonecrosis of the jaw (MRONJ), surgical therapy has recently been reported to be more effective than conservative therapy. However, some patients did not achieve complete healing, even when extensive surgery was performed. Periosteal reaction in MRONJ patients is often observed by the CT examination. Tssshe purpose of this study was to investigate the relationship between periosteal reaction and treatment outcome of MRONJ. A total of 164 surgeries in 136 patients with MRONJ at two hospitals were included in the study. Correlations between various clinical and radiographic factors and treatment outcome were examined with Cox regression analysis. The results showed that the presence of periosteal reaction, as well as primary disease involving malignant tumor, were independent risk factors related to poor outcome. Furthermore, we examined factors related to the occurrence of the periosteal reaction and found that 4 variables were significantly correlated with periosteal reaction by multivariate analysis: gender (female), site (lower jaw), primary disease (malignant tumor), and osteosclerosis (severe). The present study clarified that the cure rate after surgical treatment decreased in cases with periosteal reaction, suggesting that it is necessary to review the treatment method.

Cytochalasin E increased the sensitivity of human lung cancer A549 cells to bortezomib via inhibition of autophagy.

Cancer cells enhance autophagic activity as a survival measure against metabolic and therapeutic stresses. The inhibition of autophagy may represent a valuable sensitizing target for cancer treatment. Recently, we examined the ability of various cytochalasins to inhibit autophagy and demonstrated the potent inhibitory effect of cytochalasin E (CE) on autophagic flux. The present study was conducted to investigate whether CE inhibited autophagosome-lysosome fusion, and to determine whether CE enhanced chemotherapy-induced cell death. Cell exposure to CE led to the accumulation of microtubule-associated protein light chain 3-II (LC3-II) and sequestosome-1/ubiquitin-binding protein p62 (SQSTM1/p62) in a dose- and time-dependent manner. Cells treated with CE exhibited distinct formation of p62-positive structures on lysosome-associated membrane protein 2 (LAMP2)-positive lysosomal vesicles. CE treatment following serum starvation robustly reduced cell viability and increased expression levels of LC3-II and p62, in comparison to those of cells treated with CE alone. Furthermore, combination treatment with CE and bortezomib, an inhibitor of the 26S proteasome, showed a synergistic effect in targeting human lung cancer A549 cells. Altogether, our results demonstrated that CE treatment inhibited autophagosome-lysosome fusion, and this activity, in part, augmented bortezomib-induced cell death. Therefore, we concluded that CE may be a potentially effective therapeutic agent against lung cancer, especially in a combination therapy with proteasome inhibitors.

Multicenter Retrospective Study of the Risk Factors of Hemorrhage After Tooth Extraction in Patients Receiving Antiplatelet Therapy.

PURPOSE: To identify the risk factors affecting hemorrhage after tooth extraction in patients receiving antiplatelet therapy, this study investigated the relation between various factors and hemorrhage events after tooth extraction. PATIENTS AND METHODS: The records of 264 patients receiving antiplatelet therapy who underwent tooth extraction were retrospectively reviewed from 6 institutions belonging to the Japanese Study Group of Cooperative Dentistry with Medicine. Demographic information, hemorrhage events after tooth extraction, the presence or absence of comorbidities, antiplatelet agent, the use of preoperative antibiotics or nonsteroidal anti-inflammatory drugs, number of teeth extracted, serum creatinine level, estimated glomerular filtration rate, and alanine transaminase level were assessed. Risk factors for hemorrhage after tooth extraction were evaluated by univariate and multivariate analyses. RESULTS: The study population of 264 patients consisted of 153 men and 111 women with a mean age of 73.6 years (range, 24 to 96 yr). Six hundred ninety-four teeth were extracted (mean, 2.6 ± 2.3 teeth per patient). In patients receiving antiplatelet therapy, the frequency of hemorrhage after tooth extraction, including mild and self-controlled hemorrhages, was 17.4%. Univariate analysis showed that serum creatinine level and dual antiplatelet therapy were correlated with hemorrhage after tooth extraction (P = .001 and P = .049, respectively). Only serum creatinine was identified as an independent risk factor for hemorrhage after tooth extraction in patients receiving antiplatelet therapy (P = .037). CONCLUSIONS: The risk of hemorrhage after tooth extraction is increased in patients receiving dual antiplatelet therapy with or without chronic kidney disease. Local hemostatic treatments, such as at least suturing, are recommended.

A Lytic Polysaccharide Monooxygenase with Broad Xyloglucan Specificity from the Brown-Rot Fungus Gloeophyllum trabeum and Its Action on Cellulose-Xyloglucan Complexes.

Fungi secrete a set of glycoside hydrolases and lytic polysaccharide monooxygenases (LPMOs) to degrade plant polysaccharides. Brown-rot fungi, such as Gloeophyllum trabeum, tend to have few LPMOs, and information on these enzymes is scarce. The genome of G. trabeum encodes four auxiliary activity 9 (AA9) LPMOs (GtLPMO9s), whose coding sequences were amplified from cDNA. Due to alternative splicing, two variants of GtLPMO9A seem to be produced, a single-domain variant, GtLPMO9A-1, and a longer variant, GtLPMO9A-2, which contains a C-terminal domain comprising approximately 55 residues without a predicted function. We have overexpressed the phylogenetically distinct GtLPMO9A-2 in Pichia pastoris and investigated its properties. Standard analyses using high-performance anion-exchange chromatography-pulsed amperometric detection (HPAEC-PAD) and mass spectrometry (MS) showed that GtLPMO9A-2 is active on cellulose, carboxymethyl cellulose, and xyloglucan. Importantly, compared to other known xyloglucan-active LPMOs, GtLPMO9A-2 has broad specificity, cleaving at any position along the ß-glucan backbone of xyloglucan, regardless of substitutions. Using dynamic viscosity measurements to compare the hemicellulolytic action of GtLPMO9A-2 to that of a well-characterized hemicellulolytic LPMO, NcLPMO9C from Neurospora crassa revealed that GtLPMO9A-2 is more efficient in depolymerizing xyloglucan. These measurements also revealed minor activity on glucomannan that could not be detected by the analysis of soluble products by HPAEC-PAD and MS and that was lower than the activity of NcLPMO9C. Experiments with copolymeric substrates showed an inhibitory effect of hemicellulose coating on cellulolytic LPMO activity and did not reveal additional activities of GtLPMO9A-2. These results provide insight into the LPMO potential of G. trabeum and provide a novel sensitive method, a measurement of dynamic viscosity, for monitoring LPMO activity. IMPORTANCE: Currently, there are only a few methods available to analyze end products of lytic polysaccharide monooxygenase (LPMO) activity, the most common ones being liquid chromatography and mass spectrometry. Here, we present an alternative and sensitive method based on measurement of dynamic viscosity for real-time continuous monitoring of LPMO activity in the presence of water-soluble hemicelluloses, such as xyloglucan. We have used both these novel and existing analytical methods to characterize a xyloglucan-active LPMO from a brown-rot fungus. This enzyme, GtLPMO9A-2, differs from previously characterized LPMOs in having broad substrate specificity, enabling almost random cleavage of the xyloglucan backbone. GtLPMO9A-2 acts preferentially on free xyloglucan, suggesting a preference for xyloglucan chains that tether cellulose fibers together. The xyloglucan-degrading potential of GtLPMO9A-2 suggests a role in decreasing wood strength at the initial stage of brown rot through degradation of the primary cell wall.

Comprehensive geriatric assessment of effects of hospitalization and long-term rehabilitation of patients following lower extremity arthroplasty.

[Purpose] This study was performed to examine the effects of subacute physical therapy (PT) on activities of daily living (ADL), quality of life, and geriatric aspects of patients who underwent total knee arthroplasty (TKA) or total hip arthroplasty (THA). [Subjects] The subjects were TKA (n=56) and THA (n=39) patients who received PT on the first day of independent ADL (up to 2 weeks) and just prior to discharge (4 weeks). [Methods] The functional independence measure (FIM), grip strength, knee extension strength (KES), timed up and go (TUG) test, mini-mental state examination (MMSE), geriatric depression scale short form (GDS-15), fall efficacy scale (FES), and medical outcome study 8-item short-form health survey (SF-8) were used as outcome measure, and comorbidity involvement was also investigated. [Results] Improvements in FIM, KES, TUG, GDS-15, FES, and SF-8 scores were seen in both groups (effect size, 0.31-0.87). Poor PT effects were found for THA patients aged ≥65 years, for TKA and THA patients with an MMSE score ≤28, and for THA patients with two or more comorbidities. [Conclusion] Positive effects were seen in patients who received PT at 2-4 weeks after surgery. Thus, additional PT for approximately 2 weeks after the beginning of independent ADL may be beneficial.

[Frequency and Characterization of EPEC and EAggEC Isolated in Kawasaki City].

Thirty isolates of enteropathogenic Escherichia coli (EPEC) and 32 isolates of enteroaggregative E. coli (EAggEC) were isolated from 1,029 stool samples collected from Spring 2012 to December 2013 in Kawasaki city with the polymerase chain reaction (PCR) method targeting eae and aggR genes. Among the 30 EPEC and 32 EAggEC isolates, only 9 strains of EPEC and 8 strains of EAggEC were typed with the commercial O-antisera, whereas the majority of strains were untypable. However, several O-untypable EPEC and EAggEC strains were suggested to harbor the same O-antigen because of the detection of several examples of the same H-antigen. Analysis of the HEp-2 cell adherence test showed positive for only 2 strains (6.6%) of 30 EPEC isolates, meanwhile it showed positive for 16 strains (50.0%) of 32 EAggEC isolates. From these data, we concluded that EAggEC might be more virulent than EPEC, although both EAggEC and EPEC were isolated with almost similar rates from collected stool specimens.

Pathogenesis of Medication-Related Osteonecrosis of the Jaw: Odontogenic Infection-Preceding Type and Osteonecrosis-Preceding Type.

Introduction Medication-related osteonecrosis of the jaw (MRONJ) develops from odontogenic infection. However, there are also some cases of MRONJ developing from sites with no teeth, no root canal lesions, or no periodontal disease. This study aimed to retrospectively review radiographic images of MRONJ cases and examine the differences in characteristics between MRONJ suspected to be related to dental infection (odontogenic MRONJ) and MRONJ that occurred without dental involvement or of unknown cause (non-odontogenic MRONJ). Materials and methods One hundred and forty-five patients were diagnosed with MRONJ at Kansai Medical University Hospital and Kansai Medical University Medical Center. The following variables were investigated: sex, age, primary disease, MRONJ site, body mass index, smoking habit, diabetes, corticosteroids, type of antiresorptive agent, administration period, CT findings (separation of sequestrum, osteolysis, periosteal reaction, and osteosclerosis), trigger, leukocytes, neutrocytes, neutrophil-lymphocyte ratio, serum albumin, and serum creatinine levels. Results In the univariate analysis, significant differences between odontogenic and non-odontogenic MRONJs were found in patients whose primary disease was malignancy, receiving denosumab (DMB), and with short administration period of antiresorptive agent, no osteolysis, periosteal reaction, and serum creatinine level. In multivariate analysis, non-odontogenic MRONJ was significantly more common in patients with no osteolysis and with periosteal reaction. Conclusion Non-odontogenic MRONJ tends to occur more frequently in patients treated with high-dose DMB, and there were significantly more cases of non-osteolytic MRONJ without radiographic evidence of osteolysis or with periosteal reactions.

Postoperative Recurrence of Medication-Related Osteonecrosis of the Jaw: A Retrospective Study of 150 Patients Undergoing Surgery.

Introduction Surgery is the recommended treatment for medication-related osteonecrosis of the jaw (MRONJ). However, the disease may recur postoperatively. We reviewed imaging findings in patients undergoing three or more surgeries. Patients and methods One hundred fifty patients with MRONJ underwent surgery at our hospital. Here, we present the characteristics of 34 surgeries in nine patients (two men and seven women; mean age, 73.9 years) who underwent surgery at least three times. Results Three and six patients had maxillary and mandibular lesions, respectively. The primary disease was malignancy in eight patients, and denosumab was used in seven patients. All patients initially underwent either partial maxillectomy or marginal mandibulectomy, and segmental mandibulectomy was not performed. The number of surgeries ranged from three to six (average, 3.8). Healing was eventually achieved in seven cases, but not in two cases. Of the 27 unsuccessful surgeries, postoperative cone-beam computed tomography revealed no residual osteolysis, periosteal reaction, or osteosclerosis after seven surgeries and some residual lesions after 19 surgeries; imaging was not performed after one surgery. In contrast, among the seven successful surgeries, no residual osteolysis, periosteal reaction, or osteosclerosis was observed in all six cases in which postoperative computed tomography was performed. Conclusion Recurrence is more common in patients with residual areas of osteolysis, periosteal reactions, or mixed-type osteosclerosis, and including these areas in the resection is desirable.

Effect of oral function and postoperative eating patterns on salivary bacterial counts in gastrointestinal tract surgery patients: A preliminary study.

Background/purpose: Perioperative oral care is widely provided to prevent postoperative pneumonia and surgical site infections in patients undergoing surgery under general anesthesia. However, there is a lack of clarity regarding the kind of oral care that should be provided for different patients. The purpose of this study was to clarify the factors that influence the increase in salivary bacterial counts before and after gastrointestinal surgery to identify patients with a particular need for oral care. Materials and methods: Twenty patients undergoing gastrointestinal surgery were examined before surgery for denture use, number of remaining teeth, regular dental care, Oral Hygiene Index-Simplfied tongue coating, tongue pressure, bite pressure, masticatory efficiency, and dry mouth. Saliva samples were collected before surgery, in the fasting period after surgery, and in the oral feeding period. Total bacterial counts were determined by real-time PCR, and factors associated with bacterial counts were investigated. Results: Patients with decreased oral functions, such as tongue pressure, bite pressure, and masticatory efficiency, tended to have higher salivary bacterial counts in the preoperative, fasting, and oral feeding periods. Regarding the pre- and postoperative changes, salivary bacterial counts increased in the fasting period compared to the pre-operative period and returned to preoperative values in the oral feeding period. Conclusion: Perioperative oral care is important for patients with reduced oral function because the number of bacteria in saliva tends to be higher in such patients. As the number of bacteria in saliva increases during the fasting period, oral care is important, and oral feeding should be restarted as soon as possible.

Efficacy of perioperative oral care management in the prevention of surgical complications in 503 patients after pancreaticoduodenectomy for resectable malignant tumor: A multicenter retrospective analysis using propensity score matching.

BACKGROUND: Pancreaticoduodenectomy has been associated with a high mortality rate and significant postoperative morbidity. Recently, perioperative oral care management has been reported to be effective in preventing postoperative pneumonia and surgical site infection. In this study, we examined the effect of perioperative oral care management in reducing complications after pancreaticoduodenectomy, including surgical site infection. METHODS: This retrospective multicenter study included 503 patients who underwent pancreaticoduodenectomy at 8 facilities between January 2014 and December 2016. Among these, 144 received perioperative oral management by dentists and dental hygienists (oral management group), whereas the remaining 359 did not (control group). The oral care management program included oral health instructions, removal of dental calculus, professional mechanical tooth cleaning, removal of tongue coating, denture cleaning, instructions for gargling, and tooth extraction. The participants were matched using propensity scores to reduce background bias. Various factors were examined for correlation with the development of complications. RESULTS: The incidence of organ/space surgical site infection was significantly lower in the oral management group than in the control group (8.0% vs 19.6%, P = .005). Multivariable logistic regression analysis revealed that hypertension and lack of perioperative oral management were independent risk factors for organ/space surgical site infection. Lack of perioperative oral management had an odds ratio of 2.847 (95% confidence interval 1.335-6.071, P = .007). CONCLUSION: Perioperative oral care management reduces the occurrence of surgical site infections after pancreaticoduodenectomy and should be recommended as a strategy to prevent infections in addition to antibiotic use.

An interlaboratory study on the detection method for Escherichia albertii in food using real time PCR assay and selective agars.

Escherichia albertii is an emerging enteropathogen. Although E. albertii-specific detection and isolation methods have been developed, their efficiency on food samples have not yet been systematically studied. To establish a series of effective methods for detecting E. albertii in food, an interlaboratory study was conducted in 11 laboratories using enrichment with modified E. coli broth supplemented with cefixime and tellurite (CT-mEC), real-time PCR assay, and plating on four kinds of selective agars. This study focused on the detection efficiency of an E. albertii-specific real-time PCR assay (EA-rtPCR) and plating on deoxycholate hydrogen sulfide lactose agar (DHL), MacConkey agar (MAC), DHL supplemented with rhamnose and xylose (RX-DHL), and MAC supplemented with rhamnose and xylose (RX-MAC). Chicken and bean sprout samples were inoculated with E. albertii either at 17.7 CFU/25 g (low inoculation level) or 88.5 CFU/25 g (high inoculation level), and uninoculated samples were used as controls. The sensitivity of EA-rtPCR was 1.000 for chicken and bean sprout samples inoculated with E. albertii at low and high inoculation levels. The Ct values of bean sprout samples were higher than those of the chicken samples. Analysis of microbial distribution by 16S rRNA gene amplicon sequencing in enriched cultures of bean sprout samples showed that approximately >96 % of the population comprised unidentified genus of family Enterobacteriaceae and genus Acinetobacter in samples which E. albertii was not isolated. The sensitivity of the plating methods for chicken and bean sprout samples inoculated with a high inoculation level of E. albertii was 1.000 and 0.848-0.970, respectively. The sensitivity of the plating methods for chicken and bean sprout samples inoculated with a low inoculation level of E. albertii was 0.939-1.000 and 0.515-0.727, respectively. The E. albertii-positive rate in all colonies isolated in this study was 89-90 % in RX-DHL and RX-MAC, and 64 and 44 % in DHL and MAC, respectively. Therefore, the sensitivity of RX-supplemented agar was higher than that of the agars without these sugars. Using a combination of enrichment in CT-mEC and E. albertii isolation on selective agars supplemented with RX, E. albertii at an inoculation level of over 17.5 CFU/25 g of food was detected with a sensitivity of 1.000 and 0.667-0.727 in chicken and bean sprouts, respectively. Therefore, screening for E. albertii-specific genes using EA-rtPCR followed by isolation with RX-DHL or RX-MAC is an efficient method for E. albertii detection in food.

Medication-related osteonecrosis of the jaw without osteolysis on computed tomography: a retrospective and observational study.

Medication-related osteonecrosis of the jaw (MRONJ) is a refractory osteonecrosis caused by antiresorptive agents such as bisphosphonate and denosumab (DMB). In MRONJ surgery, computed tomography (CT) is generally used to determine the extent of bone resection. However, in some recent MRONJ cases, no abnormal findings were detected on CT. Therefore, we aimed to clarify the characteristics of MRONJ without osteolysis. This retrospective and observational study included 18 patients diagnosed with MRONJ between October 2020 and October 2022 at Department of Dentistry and Oral Surgery, Kansai Medical University Medical Center. In four of 18 patients with MRONJ, no abnormal findings such as osteolysis, separation of sequestrum, and periosteal reaction were observed on CT images at the first visit. All four patients with non-osteolytic MRONJ had malignant tumors and received high-dose DMB, and in the four patients there were no preceding dental infections such as apical lesions or periodontal disease and the trigger of MRONJ was unknown. Surgery was performed in three of the four patients. The extent of bone resection was determined using magnetic resonance imaging and intraoperative gross findings. In the future, it is necessary to establish a method for diagnosing non osteolytic MRONJ and determining the extent of bone resection.