Tokai Journal of Experimental and Clinical Medicine最新文献

Objective: The worldwide pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants remains a health threat. As sports event-related outbreaks due to long-range airborne transmission in ventilation have been reported, the present study aimed to quantify infection risk using available data and apply the results to an outbreak in an ice hockey arena.

Methods: A mathematical modeling approach was used to estimate the risk of airborne infection.

Results: A quantum was defined as the dose of airborne droplet nuclei required to cause infection in 63% of susceptible persons. The estimated quanta emission rate per infector showed a log-normal distribution with a geometric mean (GM) of 28.81, geometric deviation (GD) of 5.78, and median of 22.65 quanta/h. The estimated average time-average quanta concentration (C_avg; quanta/m³) showed a log-normal distribution with a GM of 0.08, GD of 5.80, and median of 0.06. The outdoor ventilation rate per infected person for the scenario showed a log-normal distribution with a GM of 710.96, GD of 6.22, and median of 169.17 m³/h. A higher C_avg value indicated exposure to SARS-CoV-2 due to the lower ventilation rate in the a rena a nd the large expiratory volume of athletes caused by intensive exercise.

Bezold's abscess is an extracranial complication of otitis media, in which a cervical abscess forms from the mastoid process through an ostial fistula, and is a rare condition in recent years. In this study, we experienced a X-linked agammaglobulinemia, which was discovered due to Bezold's abscess. Case: A 12-year-old boy suffering from recurrent right suppurative otitis media for three months was treated with tympanostomy and oral antibacterial therapy at a local otorhinolaryngology clinic. The patient visited the clinic due to a recurrence of symptoms. CT showed bony defects in the cortical bone and mastoid process of the lateral side of the right mastoid cell. The patient was referred to our hospital, admitted the same day and underwent emergency surgery. Intraoperative findings led to the diagnosis of acute mastoiditis and Bezold's abscess c aused b y mastoiditis spreading to the s ternocleidomastoid muscle. After drainage and administration of ABPC/SBT, the abscess disappeared, and the patient's general condition improved. Subsequently, a blood typing test performed on admission suggested the influence of low immunoglobulin levels. A close examination by the pediatric department led to a diagnosis of X-linked agammaglobulinemia. As a result, the patient receives regular immunoglobulin therapy and has been free of infection, including Bezold's abscess. CONCLUSIONS: In the case of recurrent otitis media and rare infections, congenital immune abnormalities should be considered.

Objective: To explore the involvement of bone marrow cells and angiogenesis in the pathogenesis of antiresorptive agent-related osteonecrosis of the jaw (ARONJ).

Methods: We performed micro-computed tomography (CT) and histological analyses in an ARONJ mouse model generated using bisphosphonate (BP) and cyclophosphamide (CY).

Results: Micro-CT analysis showed that BP and CY inhibited osteoneogenesis in the extraction socket. Histological analysis at 3 days after tooth extraction showed inhibition of vascular endothelial cell and mesenchymal stem cell mobilization into the extraction socket. When neovascularization of the extraction fossa was observed from as early as 1 day after extraction, it occurred predominantly in the area adjacent to the extraction fossa and close to the bone marrow cavity. In addition, the extraction fossa communicated with the adjacent bone marrow via the vasculature. Histological evaluation of the alveolar bone marrow around the extraction socket showed a decrease in bone marrow cells in the BP + CY group.

Conclusion: Both inhibition of angiogenesis and suppression of bone marrow cell mobilization are involved in the pathogenesis of ARONJ.

Purpose: Deep inspiration breath hold (DIBH) is used with adjuvant radiation therapy after left breast cancer surgery to reduce radiation dose to the heart. In this study we determined whether thoracic DIBH (T-DIBH) or abdominal DIBH (A-DIBH) should be selected based on patient background.

Methods: Three-dimensional conformal radiation therapy plans were created under the same conditions using free breathing (FB), T-DIBH, and A-DIBH CT scans of patients who had previously undergone treatment at our hospital.

Results: A-DIBH decreased the left lung dose compared to FB. In comparing T-DIBH and A-DIBH, the heart maximum and left lung doses were significantly lower in A-DIBH. The differences in the heart mean dose (Dmean) between FB, and T-DIBH and A-DIBH were correlated with the cardiothoracic ratio, heart volume, and left lung volume. The difference in the heart Dmean and the left lung dose of T-DIBH and A-DIBH correlated with the forced vital capacity (FVC).

Conclusions: A-DIBH is preferable over T-DIBH with respect to the heart and left lung doses; however, with respect to the heart Dmean, T-DIBH was more effective in reducing the dose in some cases, and the FVC was a relevant factor in this study.

Aortoesophageal fistula is a fatal disease that requires surgical treatment. Due to the patient's wishes, we chose medical treatment for aortoesophageal fistula after thoracic endovascular aortic repair for a pseudoaneurysm in the distal anastomotic site after total aortic arch replacement. Satisfactory early and long-term outcomes were obtained with complete fasting and appropriate antibiotics.

Magnetic resonance imaging (MRI) is a more useful diagnostic modality for detecting paranasal tumors compared with computed tomography (CT). We encountered a case of malignant lymphoma of the maxillary sinus. Although CT findings suggested malignancy, MRI findings indicated an inflammatory disease. The patient was a 51-year-old man with a chief complaint of right maxillary toothache. Edema in the right middle meatus and bloody rhinorrhea were observed. CT revealed r ight maxillary s inus shadow with partial bone loss, suggesting malignancy. However, MRI performed two weeks later showed an internal homogeneous lesion with neither contrast effect, nor invasion outside the maxillary sinus. The patient also had no fever, weight loss, or night sweats. Additionally, no palpable cervical lymphadenopathy was observed. Endoscopic sinus surgery was performed to confirm the diagnosis. Upon opening the maxillary sinus, highly viscous retention and a large amount of yellowish-white debris were observed. Allergic fungal rhinosinusitis was suspected. However, histopathological analysis of the debris established a diagnosis of malignant lymphoma. The debris exhibited pathological findings of necrosis. The patient remained in remission after undergoing radiochemotherapy. Malignant lymphomas of the paranasal sinuses, which have a minimal tendency for invasion but with considerable predominance of necrosis, may be diagnosed as an inflammatory disease, based on MRI findings. In cases in which a thorough physical examination could not rule out malignant lymphomas, an endoscopic biopsy should be immediately considered.

A 60-year-old Japanese woman presented with a palatal pleomorphic adenoma measuring 5 cm in size. In addition to impairments during the oral preparatory and oral transport phases, dysphagia with nasopharyngeal closure disorder was observed in the pharyngeal phase. After resection of the tumor, dysphagia resolved, and the patient was immediately able to eat a standard meal. A videofluoroscopic swallowing study confirmed improvement in the movement of the soft palate compared with the pre-operative condition.

We report a case of retroperitoneal hematoma during prophylactic heparin therapy for coronavirus disease 2019 (COVID-19). A 79-year-old man was diagnosed with COVID-19 pneumonia with possible exacerbation of fibrotic hypersensitivity pneumonia. He received a prophylactic dose of subcutaneous heparin therapy, methylprednisolone pulse therapy and Intravenous remdesivir but developed a spontaneous iliopsoas muscle hematoma, and transcatheter arterial embolization was performed. Even with a prophylactic dose of subcutaneous heparin therapy, the course should be carefully monitored, especially in patients with preexisting risk factors for hemorrhagic complications. Once retroperitoneal hematoma develops, aggressive procedures, such as transcatheter arterial embolization, should be considered to avoid fatal outcomes.

Purpose: The purpose of this study was to evaluate the lung and heart doses in volumetric-modulated arc therapy (VMAT) using involved-field irradiation in patients with middle-to-lower thoracic esophageal cancer during free breathing (FB), abdominal deep inspiratory breath-hold (A-DIBH), and thoracic DIBH (T-DIBH) images.

Methods: Computed tomography images of A-DIBH, T-DIBH, and FB from 25 patients with breast cancer were used to simulate patients with esophageal cancer. The irradiation field was set at an involved-field, and target and risk organs were outlined according to uniform criteria. VMAT optimization was performed, and lung and heart doses were evaluated.

Results: A-DIBH had a lower lung V20 Gy than FB and a lower lung V40 Gy, V30 Gy, V20 Gy than T-DIBH. The heart all dose indices were lower in T-DIBH than FB, and the heart V10 Gy was lower in A-DIBH than FB. However, the heart D_mean was comparable with A-DIBH and T-DIBH.

Conclusions: A-DIBH had significant dose advantages for lungs compared to FB and T-DIBH, and the heart D_mean was comparable to T-DIBH. Therefore, when performing DIBH, A-DIBH is suggested for radiotherapy in patients with middle-to-lower thoracic esophageal cancer, excluding irradiation of the prophylactic area.