Unveiling the role of differential growth in 3D morphogenesis: An inference method to analyze area expansion rate distribution in biological systems.

The three-dimensional (3D) morphologies of many organs in organisms, such as the curved shapes of leaves and flowers, the branching structure of lungs, and the exoskeletal shape of insects, are formed through surface growth. Although differential growth, a mode of surface growth, has been qualitatively identified as 3D morphogenesis, a quantitative understanding of the mechanical contribution of differential growth is lacking. To address this, we developed a quantitative inference method to analyze the distribution of the area expansion rate, which governs the growth of surfaces into 3D morphology. To validate the accuracy of our method, we tested it on a basic 3D morphology that allowed for the theoretical derivation of the area expansion rate distribution, and then assessed the difference between the predicted outcome and the theoretical solution. We also applied this method to complex 3D shapes and evaluated its accuracy through numerical experiments. The findings of the study revealed a linear decrease in error on a log-log scale with an increase in the number of meshes in both evaluations. This affirmed the reliability of the predictions for meshes that are sufficiently refined. Moreover, we employed our methodology to analyze the developmental process of the Japanese rhinoceros beetle Trypoxylus dichotomus, which is characterized by differential growth regulating 3D morphogenesis. The results indicated a notably high rate of area expansion on the left and right edges of the horn primordium, which is consistent with the experimental evidence of a higher rate of cell division in these regions. Hence, these findings confirm the efficacy of the proposed method in analyzing biological systems.

Impact of environmental asymmetry on epithelial morphogenesis.

Epithelial folding is a universal biological phenomenon in morphogenesis, typical examples being brain gyri, villi of the intestinal tract, and imaginal discs in invertebrates. During epithelial morphogenesis, the physical constraints imposed by the surrounding microenvironment on epithelial tissue play critical roles in folding morphology. In this study, we focused on the asymmetry of the environmental constraints sandwiching the epithelial sheet and introduced the degree of asymmetry, which indicates whether the basal or apical side of the epithelium is closer to the constraint wall. Then, we investigated the relationship between the degree of asymmetry and epithelial folding morphology using three-dimensional vertex simulations. The results show that the folding patterns of the epithelial sheets change from spot patterns to labyrinth patterns and then to hole patterns as the degree of asymmetry changes. Furthermore, we examined the pattern formation in terms of the equation of out-of-plane displacement of the sheet derived from the mechanical energy functional.

[Portal vein thrombosis associated with idiopathic hypereosinophilic syndrome].

A 35-year-old man who previously underwent splenectomy for hereditary spherocytosis at age 29 visited our hospital complaining of fatigue that had started 7 days ago and right upper abdominal pain. Laboratory data showed increased white blood cell and eosinophil count accompanied by severe transaminitis and clotting abnormalities. Computed tomography scan showed multiple embolisms in the portal vein, superior mesenteric vein, right pulmonary artery, and inferior vena cava. Severe liver damage presumably caused by portal vein thrombosis was also observed. Anticoagulant therapies consisting of continuous arterial infusion of urokinase from the superior mesenteric artery and an intravenous infusion of recombinant human thrombomodulin and heparin dissolved the systemic thrombosis. Concurrently administered prednisone decreased the eosinophil count. With regard to eosinophilia, we were unable to find any connective tissue diseases, antibodies to parasites, or genetic anomalies including PDGFRA, PDGFRB, and FGFR1. Hence we diagnosed the patient with idiopathic hypereosinophilic syndrome (HES). Although thromboembolisms in patients with HES have been reported, the literature on portal vein thrombosis associated with HES is scarce. In the present case, the previous splenectomy may have contributed to the portal vein thrombosis.

[Switch from emergency medicine to disaster medicine].

Disaster medical system in Japan has been changing after huge disaster attack. Disaster Medical Assistance Team (DMAT) was established on 1995 after the Hanshin-Awaji Great Earthquake and played important role in the Great Eastern Japan Earthquake on 2011. The action of DMAT is specialized within acute phase. Continual medical aid activity is required from acute phase to chronic phase. After DMAT evacuation, Japan Medical Association Team (JMAT), Japanese Red Cross Teams, Medical university teams and many other medical teams work sequentially in the disaster area. On the other hand, unbalance in the disaster area is occurred. Disaster medical coordinator accommodates that unbalance situation. Development of receive system for many medical assistance teams will be required.

CSF orexin A concentrations and expressions of the orexin-1 receptor in rat hippocampus after cardiac arrest.

Orexins/hypocretins are neuropeptides that have various physiological effects, including the regulation of feeding behavior, neuroendocrine functions and sleep-wake cycles. Recent studies have suggested that the orexin system may also be involved in brain ischemic reactions. It is also known that changes in sleep patterns, energy homeostasis and neuroendocrine functions are often occur in neurological conditions associated brain ischemia. In the current study, we investigated the time-dependent changes in cerebrospinal fluid (CSF) orexin-A concentration and the expression of the orexin-1 receptor (OX1R) in the rat hippocampus after global ischemia-reperfusion (5 min cardiopulmonary arrest), which is known to induce delayed cell death in the CA1 region of the hippocampus. The CSF orexin-A concentration was elevated transiently at 24 h after ischemia. On days 2 and 4 after ischemia, CSF orexin concentrations were significantly reduced relative to the baseline, and returned to the baseline level by day 7. These changes were correlated with increased expression of OX1R in the CA1 on days 1 and 2 post-ischemia. These results suggest that dynamics of orexin signaling observed may have functional roles for neuronal damage associated with transient ischemia.

Significance of consecutive bilateral surgeries for patients with acute subdural hematoma who develop contralateral acute epi- or subdural hematoma.

BACKGROUND: Although rare, patients with acute subdural hematoma (ASDH) because of severe head injury can develop contralateral acute epi- or subdural hematoma, requiring consecutive surgical procedures. The choice of treatment strategies for such patients is clinically important. METHODS: Among 88 patients with ASDH who were surgically treated over 13 years, we encountered and studied 5 patients who developed contralateral acute epi- or subdural hematoma (5.7%). RESULTS: All 5 patients were male, ranging in age from 17 to 40. According to the Glasgow Coma Scale on admission, 1 patient was rated 3, 1 was 4, 1 was 5, and 2 were 6. All patients underwent consecutive surgical procedures for ASDH and contralateral ASDH and/or acute epidural hematoma, and were given postoperative supportive therapy with barbiturates and mild hypothermia. Patients' outcomes according to the Glasgow Outcome Scale were as follows: 1 patient, good recovery (20.0%); 1, mild disability (20.0%); 2, severe disability (40.0%), and 1, persistent vegetative state (20.0%). No patients died. Although decompressive craniectomy and evacuation of hematoma may lead to contralateral acute epi- or subdural hematoma in patients with ASDH, this therapy is justified because hematoma irrigation with trephination therapy has a poor outcome for comatose patients. CONCLUSION: Awareness of intraoperative brain swelling is important, as it suggests the development of contralateral hematoma. Immediate computed tomography and a rapid return to the operating room are therefore critical.