The Fe-FeSi phase diagram at Mercury's core conditions.

Mercury's metallic core is expected to have formed under highly reducing conditions, resulting in the presence of significant quantities of silicon alloyed to iron. Here we present the phase diagram of the Fe-FeSi system, reconstructed from in situ X-ray diffraction measurements at pressure and temperature conditions spanning over those expected for Mercury's core, and ex situ chemical analysis of recovered samples. Under high pressure, we do not observe a miscibility gap between the cubic fcc and B2 structures, but rather the formation of a re-entrant bcc phase at temperatures close to melting. Upon melting, the investigated alloys are observed to evolve towards two distinct Fe-rich and Fe-poor liquid compositions at pressures below 35-38 GPa. The evolution of the phase diagram with pressure and temperature prescribes a range of possible core crystallization regimes, with strong dependence on the Si abundance of the core.

COVID-19 transmission in dental and oral/maxillofacial surgical practice during pandemic: questionnaire survey in 51 university hospitals in Japan.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has become a major public health problem. Dental procedures that generate aerosols are considered to impose a high risk of infection; therefore, dental professionals, such as dentists and dental hygienists, may be at high risk of viral transmission. However, few studies have reported COVID-19 clusters in dental care settings. AIM: To investigate whether dental and oral/maxillofacial procedures are associated with the occurrence of COVID-19 clusters and measures taken to prevent nosocomial infection in dental clinics. METHODS: An online questionnaire survey on clinical activities (administrative control), infection control measures (environmental/engineering control, personal protective equipment, etc.), and confirmed or probable COVID-19 cases among patients and clinical staff was administered to the faculties of the dental and oral/maxillofacial surgical departments of university hospitals. FINDINGS: Fifty-one faculty members completed the questionnaire. All members were engaged in the treatment of dental and oral surgical outpatients and actively implemented standard precautions. Fourteen faculty members treated patients with COVID-19, but no infections transmitted from the patients to the medical staff were observed. In seven facilities, patients were found to have the infection after treatment (medical staff came in close contact), but there was no transmission from patients to medical staff. Four facilities had medical staff with infections, but none of them exhibited disease transmission from staff to patients. CONCLUSION: COVID-19 clusters are unlikely to occur in dental and oral surgical care settings if appropriate protective measures are implemented.

Impact of muscle volume loss on acute oral mucositis in patients undergoing concurrent chemoradiotherapy after oral cancer resection.

This study evaluated the association between skeletal muscle mass depletion and severe oral mucositis in patients undergoing concurrent chemoradiotherapy after oral cancer resection. Skeletal muscle mass was evaluated in 60 patients using the skeletal muscle index, which was based on skeletal muscle cross-sectional area (on computed tomography) at the level of the third lumbar vertebra. In accordance with the grading criteria of the Radiation Therapy Oncology Group, patients with a grade ≥3 were defined as having severe oral mucositis. Multivariate logistic regression analysis was used to evaluate independent risk factors for severe oral mucositis. Eleven patients (18.3%) were diagnosed with low skeletal muscle mass. Severe oral mucositis occurred in 17 (28.3%) patients, and the mean skeletal muscle index was 42.8 cm2/m2. A low skeletal muscle mass (hazard ratio 18.1; P=0.001) and a chemotherapy regimen consisting of 5-fluorouracil and cisplatin (versus cisplatin only) (hazard ratio 5.5; P=0.015) were independent risk factors for severe oral mucositis. Future prospective studies are warranted to identify effective pre- and perioperative exercises and nutrition programmes to increase low skeletal muscle mass and reduce the incidence of severe oral mucositis in patients undergoing concurrent chemoradiotherapy after oral cancer resection.

Impact of sarcopenia on postoperative surgical site infections in patients undergoing flap reconstruction for oral cancer.

Sarcopenia is characterized by progressive and generalized loss of skeletal muscle mass and strength. The aim of the study was to investigate the impact of skeletal muscle mass on surgical site infection (SSI) in flap reconstruction for defects after oral cancer resection. The subjects were a non-randomized, retrospective cohort of 106 patients who underwent this procedure after preoperative abdominal-lumbar computed tomography (CT). Cross-sectional areas (cm2) of skeletal muscles in the L3 region were measured by manual outlining on CT images. These areas were then normalized for height (cm2/m2) and defined as the skeletal muscle index (SMI). Recipient site SSI occurred in 28 patients (26.4%). Lower body mass index, haemoglobin and SMI were significantly related to recipient site SSI in univariate analysis (P<0. 05). In a multiple logistic regression model, lower SMI was a significant risk factor for recipient site SSI (odds ratio = 3.95 per 10 cm2/m2 decrease, P=0. 005). This result suggests that increasing skeletal muscle mass by exercise or nutrition before surgery may prevent recipient site SSI after resection of oral cancer and subsequent reconstruction.

Tongue surface model can predict radiation tongue mucositis due to intensity-modulated radiation therapy for head and neck cancer.

Acute radiation tongue mucositis has a profound effect on talking and eating. We examined whether the dose-volume histogram obtained from the tongue surface model correlates with mucositis severity, and whether it is useful for predicting acute radiation tongue mucositis in patients with head and neck cancer treated with intensity-modulated radiation therapy. Thirty-six patients who received intensity-modulated radiation therapy for head and neck cancer were analysed for acute radiation tongue mucositis according to the Common Terminology Criteria for Adverse Events, version 4.0, as well as the Radiation Therapy Oncology Group scoring systems. The corresponding high-dose locations in anatomical sub-regions in the tongue surface model and the development of high-grade acute radiation tongue mucositis were compared. The mucositis sites coincided with the high-dose anatomical sub-regions in the tongue surface model. There was a clear dose-response relationship between the mean dose to the tongue and the acute radiation tongue mucositis Radiation Therapy Oncology Group grade. According to the dose-volume histogram, patients receiving 16.0-73.0 Gy to the tongue were susceptible to grade 2-3 toxicity. The tongue surface model can predict the site and severity of acute radiation tongue mucositis. In future, radiation treatment plans ccould be optimized using this model.

Standard morphology of the oral commissure and changes resulting from reconstruction for defects involving the commissure.

The aim of this study was to characterize the standard morphology of the oral commissure and to describe the changes after reconstruction in patients with through-and-through cheek defects involving the oral commissure. Indices for the morphological analyses of the commissure were derived from examinations of 50 normal Japanese volunteers. Ten patients with full-thickness cheek defects involving the commissure were then evaluated. All of these patients underwent free flap reconstruction with vermilion advancement flaps from the remaining vermilion. The morphology of the commissure with the mouth closed was classified based on the point of entrance of the vermilion into the oral cavity. In normal volunteers, the commissure pattern consisting of the entrance of the upper vermilion into the oral cavity before the lower vermilion and just prior to forming the oral commissure was considered to be the standard. However, in the reconstructed cases, there was an increase in the pattern in which the lower vermilion enters the oral cavity before the upper vermilion for the remaining commissure postoperatively, especially when the lower lip defects were greater than those of the upper lip. It is important to refer not only to the standard morphology of the commissure, but also to the changes according to the extent of resection and the method of reconstruction.

Risk factors for postoperative delirium in patients undergoing free flap reconstruction for oral cancer.

The aim of this study was to investigate risk factors for postoperative delirium in patients undergoing free flap reconstruction for defects after oral cancer resection. This was a non-randomized, retrospective cohort study involving 102 patients who underwent oral cancer resection and free flap reconstruction. Data were collected from the medical records. Postoperative delirium occurred in 34 patients (33.3%), of whom 27 were male and seven were female. High preoperative total protein and albumin, diabetes mellitus, history of smoking, use of hypnotics or antipsychotics, time until getting out of bed after surgery, and postoperative insomnia were significantly related to delirium in the univariate analysis (P<0.05). In a multiple logistic regression model, high preoperative albumin (odds ratio 4.45), postoperative insomnia (odds ratio 10.72), and history of smoking (odds ratio 2.91) were significant risk factors for delirium (P<0.05). The analysis of laboratory data before and after surgery showed greater decreases in albumin, total protein, and haemoglobin after surgery in patients with postoperative delirium than in those without this condition. These results show that the perioperative maintenance of nutritional status and early postoperative management of the sleep cycle are important to prevent delirium after oral cancer resection and free flap reconstruction.

Clinicopathological investigation of odontogenic fibroma in tuberous sclerosis complex.

Tuberous sclerosis complex (TSC) is an autosomal dominant inherited disease characterized by systemic hamartoma and diverse systemic features. TSC1 and TSC2 are the causative genes, and mental retardation, epileptic seizures, and facial angiofibroma develop in many patients with the disease. The case of a patient with TSC who developed a central odontogenic fibroma of the mandible is reported here. The patient was a 21-year-old woman who was referred with a swelling of the labial gingiva in the region of the right lower lateral incisor and canine. Dental radiography revealed a multilocular radiolucent region with a clear boundary. The right lower lateral incisor and canine were continuous with the lesion and thus were excised en bloc. The lesion was encapsulated and easily dissected. The diagnosis on immunohistological staining was odontogenic fibroma without an epithelial component. TSC1/2 gene mutation causes abnormal activation of mammalian target of rapamycin (mTOR) downstream of the PI3K-AKT pathway. The odontogenic fibroma in this patient was positive for mTOR, suggesting that the development of the odontogenic fibroma was the result of abnormal activation of mTOR, as in angiofibroma. The clinical course of this patient is presented and the developmental mechanism of central odontogenic fibroma is discussed.

A comparison of brachytherapy and surgery for the treatment of stage I-II squamous cell carcinoma of the tongue.

The treatment method for early stage tongue cancer is still controversial in Japan. The aim of this study is to compare the prognosis for patients with early tongue cancer treated with brachytherapy and surgery. A retrospective study was conducted to compare the efficacy of low-dose-rate brachytherapy (LDR), high-dose-rate brachytherapy (HDR), and surgery for early tongue cancer. A total of 180 patients with stage I-II tongue cancer were divided into three treatment groups: LDR (78), HDR (26), and surgery (71). Local recurrence was seen in thirteen patients (17%) of the LDR, nine (35%) of the HDR, and four (6%) of the surgery group. After salvage therapy, final local cure was obtained for 71 patients (91%) of the LDR, 22 (85%) of the HDR, and 71 (100%) of the surgery group. Neck failure was recorded for eight patients in the LDR, six in the HDR, and three in the surgery group. The respective 5-year overall survival rates for the LDR, HDR and surgery groups were 84.0%, 72.9%, 95.4% for stage I, and 72.2%, 51.5%, 93.8% for stage II. These findings show that surgery is the optimal treatment method for patients with stage I-II tongue cancer.

Factors influencing internal jugular vein patency after neck dissection in oral cancer.

The objective was to investigate factors influencing internal jugular vein stenosis or occlusion after neck dissection, including the reconstructive procedure. The subjects were 73 patients (81 veins) who underwent a modified radical neck dissection, in which the internal jugular vein was preserved, or an extended supraomohyoid neck dissection (E-SOHND). All procedures were performed by the same surgeon. Internal jugular vein patency was evaluated by contrast-enhanced computed tomography. Patency was evaluated in relation to gender, side of dissection, number of pathological lymph node metastases, extracapsular spread of lymph node metastases, radiotherapy, and the reconstruction method (no reconstruction, free flap, or pedicle flap). All internal jugular vein occlusions were on the left side and all except one of these patients underwent radiotherapy. Thus, radiotherapy and left side dissection were significant risk factors for occlusion. Free flap reconstruction was not a risk factor for vein stenosis or occlusion. Patients undergoing reconstruction with pedicled musculocutaneous flaps or E-SOHND were less likely to have vein occlusion. Particular care is required for left neck dissection in patients who have undergone radical neck dissection on the right side. This study suggests that covering the internal jugular vein with the muscle might prevent vein occlusion.

Adult T-cell leukemia involving the central nervous system after remission of adult respiratory distress syndrome.

We report a rare case of adult T-cell leukemia (ATL) in which the patient had an acute type of ATL involving the central nervous system (CNS) after remission of adult respiratory distress syndrome (ARDS) due to human T lymphotropic virus type 1 associated bronchopneumopathy. A 62-year-old woman was admitted to the hospital because of ARDS. Pulse therapy with methylprednisolone improved ARDS, but she fell into a coma due to ATL and CNS invasion 5 months after recovery. Although chemotherapy decreased the fraction of abnormal lymphocytes, her consciousness level did not improve and she died.

Evaluation of T-classifications of upper gingival and hard palate carcinomas--a proposition for new criterion of T4.

Most carcinomas of upper gingiva and hard palate are classified as T4 stage on the basis of the UICC criteria, since they easily invade the underlying bone tissue. We classified 43 patients with squamous cell carcinoma of the upper gingiva in terms of three criteria: (1) the original T-classification by UICC, (2) the classification by the Japan Society for Head and Neck Cancer (JSHNC), and (3) a new classification in which the maxillary sinus or nasal floor is used as the defining borderline for T4 (MSF classification). Our study demonstrated that the new classification was superior with regard to distribution of patients by T stage, correlation with prognosis and choice of treatment method.

Establishment and characterization of a human adenoid cystic carcinoma line of the salivary gland which is serially transplantable and spontaneously metastasises to the lung in nude mice.

Adenoid cystic carcinoma (ACC) is a rare malignant tumour of the head and neck occurring in the salivary glands. We established a human ACC line which is serially transplantable in nude mice and designated it as KOA-1. The KOA-1 tumour doubled in 9.3 days and retained the histological characteristics of a solid pattern of ACC even after 22 serial passages. The KOA-1 metastasised to the lung when transplanted subcutaneously into the back. This tumour line may serve as a useful model for exploration of the biological behaviour and treatment of human ACC.

Functional and aesthetic reconstruction of full-thickness cheek, oral commissure and vermilion.

PURPOSE: This paper presents surgical techniques for reconstruction of the cheek, oral commissure and vermillion in the repair of full-thickness cheek defects after resection of buccal-mucosal squamous cell carcinoma. PATIENTS AND METHODS: Four reconstructions in one-stage surgery with either a free radial forearm flap or a rectus abdominis musculocutaneous flap for cheek and oral commissure were carried out. There were combined with a new approach for vermillion advancement flaps. Most challenging was the need not only for morphological reconstruction of the orifice, but also for physiological reestablishment of sphincteric and sensory functions in the vermillion. RESULTS: Morphological and physiological reconstruction of the lip with sphincteric and sensory functions was attained. CONCLUSION: This valuable reconstruction technique was demonstrated in large, full thickness defects involving the cheek, oral commissure and vermilion.

Disseminated carcinomatosis of bone marrow from submucosal carcinoma in adenoma of the rectum.

A 62-year-old man was admitted because of paresis of the legs and a bleeding tendency. He was diagnosed as metastatic bone cancer with disseminated intravascular coagulation (DIC). In spite of treatment, his general condition progressively deteriorated and he died of respiratory failure 13 days later. Autopsy revealed a carcinoma in adenoma in the rectum. Although the depth of cancer invasion was confined to the submucosal layer, disseminated carcinomatosis of the bone marrow and tumor emboli in blood vessels of the lung were present.

Cytomegalic inclusion disease presenting acute intrahepatic cholestasis.

An 83-year-old man suffering from pulmonary emphysema was admitted to our hospital because of jaundice. He was diagnosed as acute intrahepatic cholestasis but the etiology could not be determined during the treatment period. In spite of treatment, the jaundice worsened progressively without any elevation in serum transaminase, and he died of respiratory failure 58 days later. An autopsy revealed a generalized cytomegalic inclusion disease, predominantly in the biliary tracts, liver and lungs. This is a rare case of cytomegalic inclusion disease presenting acute intrahepatic cholestasis without any elevation of transaminase during the clinical course.

Peritonitis due to Mycobacterium fortuitum infection following gastric cancer surgery.

Mycobacterium fortuitum is a well-documented cause of nosocomial infection. However, no studies have reported peritonitis with M. fortuitum as a postoperative complication. We describe a case of peritonitis with M. fortuitum biovariant peregrinum following gastric cancer surgery. Gram-positive bacterial infection coexisted. Although the source of the infection was unclear, the patient was successfully treated with drainage tube exchange and combination therapy consisting of sparfloxacin, clarithromycin, and imipenem/cilastatin sodium. Thus for postoperative infectious pathogens, not only bacteria but also nontuberculous mycobacteria should be considered.

Pyogenic clavicular osteomyelitis associated with disseminated intravascular coagulation and acute renal failure in a patient with non-insulin-dependent diabetes mellitus.

Pyogenic osteomyelitis is often accompanied by diabetes, but the disease in the clavicula has rarely been reported. We describe an unusual case of a 53-year-old man with poorly controlled non-insulin-dependent diabetes mellitus who presented with pyogenic clavicular osteomyelitis and developed DIC and acute renal failure. A 67Ga scintigram revealed an abnormal accumulation of the isotope in the right clavicula, where magnetic resonance imaging (MRI) showed inflammatory changes. This suggests that a 67Ga scintigram and MRI are of clinical value for the early diagnosis of the disease. Antibiotic chemotherapy with gamma-globulin and gebexate mesilate, and hemodialysis almost cured his serious condition.

The role of radiotherapy for patients with adenoid cystic carcinoma of the salivary gland.

OBJECTIVE: Adenoid cystic carcinoma (ACC) is a rare malignant tumor occurring in the salivary gland that has some characteristic features, including slow growth, extremely diffuse invasion, and a high incidence of distant metastasis. The indication of radiotherapy (RT) for ACC is controversial. The aim of this study was to examine the usefulness of RT for patients with ACC. STUDY DESIGN: The study group was composed of 17 patients (18 lesions) with ACC of the salivary gland who underwent RT. They were divided into 3 groups: (1) those who underwent RT alone for a primary tumor, (2) those who underwent RT alone for a recurrent tumor after surgery, and (3) those who underwent postoperative RT because of a histologically positive surgical margin. The clinical course of each patient was examined retrospectively. RESULTS: Of the 11 patients undergoing RT alone for a primary or recurrent tumor, 5 showed complete remission of the tumor, and 3 were free from local recurrence for a long period. Seven patients who underwent postoperative RT seemed to show better local control than did those who did not undergo postoperative RT, although there were no significant differences. CONCLUSIONS: We find RT to be an effective treatment procedure, especially for those who had an inoperable, advanced tumor or who had distant metastasis. Postoperative RT was recommended for those who had a histologically positive surgical margin.

Tumor-doubling time and onset of pulmonary metastasis from adenoid cystic carcinoma of the salivary gland.

Adenoid cystic carcinoma (ACC), an uncommon malignancy in the head and neck region, invades diffusely and often metastasizes to the lung, although the growth rate is very slow. A retrospective study was conducted in 30 patients with ACC to ascertain the frequency of pulmonary metastasis, the doubling time of metastatic tumor deposits, and the time of onset for pulmonary metastasis. The following results were obtained: (1) Of 30 patients with ACC, 21 had pulmonary metastases (4 initially and 17 during observation), 7 were free of metastases but have not been observed for 5 years, and 2 were free of metastases for more than 5 years but less than 10 years after the initial treatment. The cumulative metastasis rate at 5 and 10 years for this group of patients was 70% and 100%, respectively. (2) Patients with T1 or T2 tumors that have a tubular or cribriform histopathologic pattern showed pulmonary metastases about 20 months later than those with T3 or T4 tumors and a solid pattern. However, the final metastasis rate did not differ between the 2 groups after a long period. (3) The tumor doubling time of the metastatic deposits of ACC was 86 to 1064 days with an average of 393 days, which was much longer than that of most other malignant neoplasms reported previously. (4) The time of onset of pulmonary metastasis was calculated to be much earlier (average of 227 months) before the first visit. These findings suggest that the treatment method for ACC should be chosen with the consideration that many of the patients may have occult pulmonary metastases at the time of their initial evaluation.