An Anatomical Dissection Method for Observation of Fibrous Facial Structures.

BACKGROUND: In recent years, structures including the superficial musculoaponeurotic system and retaining ligaments that support the facial soft tissue have been clarified. However, these structures are very difficult to observe in their entirety by the standard gross anatomical procedure (ie, dissection from superficial to deep layers). Furthermore, accurate descriptions of these structures are rare in both anatomical and plastic surgery textbooks. The aim of this study was to clarify the facial fibrous structures in a gross anatomical view. METHODS: The authors' novel method used soft facial tissue and bone. The tissue was fixed in gelatin and sectioned at a thickness of 5 to 10 mm. Each section was placed on a wooden board; the bone was then pinned, and the skin was pulled outward with sutures to hyperextend the soft tissue. Subsequently, the loose connective tissue was torn and fat tissue was removed under a surgical microscope. After the removal of fat tissue, the fibrous facial structures (eg, the superficial musculoaponeurotic system and retaining ligaments) could be observed clearly. RESULTS: The thickness of the sections allowed three-dimensional observation, such that a structure located deep within a section could be clearly observed. The expansion of soft tissue facilitated observation of the facial layer and fibrous structures, and the locations of nerves and vessels. Therefore, the facial layer structure was readily discerned. CONCLUSION: This method is likely to be very useful in the field of plastic surgery because it enabled intuitive identification of facial layers and their characteristics. CLINICAL RELEVANCE STATEMENT: The dissection method developed by the authors reveals the connected morphology of each tissue of the face, thus providing basic data for analyzing soft tissue changes due to aging and gravity. This will be useful for the development of anti-aging medicine.

Effect of the third dose of BNT162b2 COVID-19 mRNA vaccine on anti-SARS-CoV-2 antibody levels in healthcare workers.

PURPOSE: Administration of three doses of Pfizer-BioNTech BNT162b2 COVID-19 mRNA vaccine was completed in Japan in the spring of 2022. This study aimed to evaluate the antibody responses, and kinetics of three doses of vaccine in healthcare workers (HCWs). PATIENTS AND METHODS: We conducted a longitudinal cohort study with HCWs, who had no history of COVID-19 or serologic evidence of SARS-CoV-2 infection, from a single hospital. Immunoglobulin G (IgG) titers of anti-SARS-CoV-2 spike protein (SP) and nucleocapsid protein (NP) titers were measured using an automated chemiluminescent enzyme immunoassay system. RESULTS: A total of 636 HCWs participated in the study. The anti-SP IgG titers decreased slowly after the second dose of the BNT162b2 vaccine in all participants, and robust antibody response was observed after the third dose of the vaccine. The peak anti-SP IgG titer after the third dose was approximately 4.1-fold higher than that after the first and second doses, and the rate of decrease in the anti-SP IgG titer after the third dose was significantly more gradual, than that after the second dose. After the second dose of vaccine, the antibody response was weaker in older participants than in younger participants, and in males than in females respectively, whereas the response to the third dose of vaccine did not differ significantly by sex or age. Adverse events following immunization were generally mild to moderate. CONCLUSION: The third dose of the BNT162b2 vaccine induced a significant and sustained increase in anti-SP IgG titers, and was generally safe and well-tolerated.

Closure of Intractable Enterocutaneous Fistula with a Rectus Abdominis Musculocutaneous Flap.

Large enterocutaneous fistulas of the small intestine are rare and difficult to close, particularly if the fistula is associated with massive leakage of digestive juice and the residual intestinal tract is too short for anastomosis. We present a patient who underwent small bowel resection and secondary anastomosis following massive necrosis of the small intestine due to superior mesenteric artery thrombosis. After resection of an enterocutaneous fistula and reanastomosis, the residual small bowel was only 70 cm long with a persistent fistula. We successfully closed the fistula by employing a hinged rectus abdominis musculocutaneous flap. Here, we report our procedure for treating a large enterocutaneous fistula without performing laparotomy and bowel resection.

Novel Cadaver Injection Method Using Latex and Magnetic Fluid.

Vascular injection into extracted tissue may be associated with leakage due to excessive local injection pressure. Historically, this complication has been impossible to resolve because the injection pressure has been the only available force with which to send the agent to the peripheral vasculature. We have developed a new vascular injection method that utilizes a material affected by magnetic force and is therefore not solely dependent upon the injection pressure. We mixed the same weights of latex and magnetic fluid and injected the solution into the arterial stump of an extracted tissue specimen. Next, we used a permanent magnet to attract the agent into the peripheral vasculature. We repeated the injection and magnetic application until no further fluid could be injected. We used this method in 20 formalin-fixed tissue specimens. The vessels were clearly observable through to the peripheral areas, and leakage from the injected artery was minimal. This new agent has several beneficial characteristics: it is X-ray impermeable, is durable in the face of chemical insult, and allows for easy visual observation. The injected tissue can be studied for X-ray film examination, tissue clarification, and gross anatomical dissection. Additionally, this method can be applied to both fresh and formalin-fixed tissue. We consider that this method has the potential to expand the applications of injection studies.

A new modified Pudendal Thigh Flap of vaginoplasty including reconstruction of vaginal vestibule.

We modified the conventional Pudendal Thigh Flap (PTF) on the vaginoplasty including reconstruction of vaginal vestibule. After the operation, no stenosis of the vaginal vestibule and opening of the vagina was observed. It is believed that our technique is cosmetically and functionally possible and a useful method.

Unfiltered xenon light is useful for photodynamic therapy with acridine orange.

We have clarified that photodynamic therapy (PDT) with acridine orange (AO) exerts a rapid and strong cytocidal effect on mouse osteosarcomas, both in vitro and in vivo, and have sought to apply this therapy to patients with musculoskeletal sarcomas, in order to reduce the surgical margin and obtain better limb function after tumor resection in limb salvage surgery. Some clinical studies have reported that the local recurrence rate after limb salvage surgery in patients receiving PDT therapy was less than 10% and that the limb functions recovered to nearly normal in these patients. For these basic and clinical studies, we used a blue light beam filtered from a xenon lamp for the AO excitation, because of its maximal absorption. However, the relationship between the cytocidal effect of PDT and the wavelength or illuminance (lux) of the excitation light in AO-PDT is unknown. Therefore, we investigated the cytocidal effects of AO-PDT on mouse osteosarcoma cells using lights of various illuminances and wavelengths from a xenon lamp. Our results revealed that, while the blue and green filtered lights exerted cytocidal effects depending on their illuminance, orange light exerted no such effect. Blue light showed the strongest cytocidal effect under constant illuminance. However, unfiltered light with 10 times the illuminance of blue light yielded a much stronger cytocidal effect, which was deduced not to be due to DNA injury by ultra-violet light or heat generation by ultra-red light, since a xenon lamp emits little of either light. Based on these results, we conclude that, for effective AO-PDT in clinical practice, strong unfiltered light from a xenon lamp is more effective and feasible than weak filtered blue light.

Acridine orange excited by low-dose radiation has a strong cytocidal effect on mouse osteosarcoma.

The study was conducted to clarify the cytocidal effect of combination therapy consisting of administration of acridine orange (AO), which is a photosensitizer, and radiation therapy using in vitro and in vivo mouse osteosarcoma models. The results revealed that AO combined with low-dose X-ray irradiation of about 1-5 Gy had a strong cytocidal effect on the cultured mouse osteosarcoma cells regardless of their chemosensitivity, and that this combination therapy inhibited growth of the in vivo mouse osteosarcoma by induction of tumor necrosis. This effect was inhibited by L-histidine, but not by mannitol. These findings suggested that AO might be excited by X-rays and kill osteosarcoma cells through the release of singlet oxygen, which is toxic to living cells. This mechanism is similar to that of photodynamic therapy with AO.