This paper reports the pathological changes and MDA content of the brain tissue in the early stage of cerebral ischemia due to middle cerebral artery occlusion (MCAO) in Wistar rats. The neurones showed changes of the rough endopiasmic reticulum and the mitochondrium as early as 2 minutes after MCAO. Under the light microscope, "ischemsc cells" with shrunken and condensed cytoplasm and nucleus appeared 10 minutes after MCAO. The end-product of lipid peroxidation, MDA, in the isch. emic brain tissue also significantly increased 2 minutes after MCAO, being correlated synchronously with the ultrastructural changes of the neurones. This suggested that free radicals play a role in the early stage of brain injury due to ischemia.

Objective To study arterial distribution of rectus abdominis musculocutaneous flap and to evaluate whether it can be divided into several units for reconstruction. Methods The arteries of the rectus abdominis musculocutaneous flap were studied on 60 sides of cadavers by dissection and angiography. Results The superior epigastric artery (SEA) and the inferior epigastric artery (IEA) continued in a longitudinal direction. Most of their branches took on a typical spiral configuration and communicated with each other within muscle above the level of umbilicus. Many perforating arteries penetrated through the anterior rectus sheath to get to the overlying skin, but the highest concentration of major perforators were in the paraumbilical area. The inferior epigastric artery was more significant than superior epigastric artery in supplying the skin of the musculocutaneous flap. Based on thefstudies of the vascular anatomy of muscles, we could classify arterial distribution into 3 types: type Ⅰ (SEA 26.5 %, IEA 34.6%) revealed a single main intramuscular artery: type Ⅱ (SEA 64.7 %, IEA 48.1%) had two major intramuscular branches; type Ⅲ (SEA 8.8%, IEA 17.3 %) revealed three intramuscular branches. Our anatomic studies showed that the superior and inferior epigastric artery bifurcated or divided into more than two main branches in the majority of cases (SEA 73.5%, IEA 65.4%). Conclusion The rectus abdominis musculocutaneous flap could often be divided into several regions for breast construction which is based on the distribution of each branch of the artery.

Objective:To investigate the types, incidences, and clinical characteristics of shock in polytrauma patients at different stages after polytrauma.Methods:A retrospective study was conducted on polytrauma patients admitted to multiple trauma centers from June 2020 to December 2021. The inclusion criteria were patients >18 years old and treated due to polytrauma. Exclusion criteria included an admission time of more than 48 h after trauma, a history of malignancy, or metabolic, consumptive, and immunological diseases. The early stage was defined as the period of ≤48 h after polytrauma, and the middle stage was defined as the period between 48 h and 14 days. The patient’s medical history, clinical manifestations, laboratory tests, imaging examination, injury severity score (ISS), and Glasgow coma scale (GCS) were collected. The types, incidences, and clinical characteristics of shock in different stages after polytrauma were analyzed, according to the diagnostic criteria of each type of shock. The differences between the groups were compared by Student’s t test, χ2 test or Mann-Whitney U test. Results:The incidence of the early and middle stage shock after polytrauma were 73.1% and 36.4%, respectively, with statistically significant difference between stages ( P<0.01). There were significant differences in the incidence of hypovolemic shock (83.6% vs. 28.4%), distributed shock (13.7% vs. 80.9%) and cardiogenic shock (3.5% vs. 6.6%) between stages (all P<0.05). The incidence of obstructive shock (8.4% vs. 9.7%, P>0.05) was similar between stages. The incidence of undifferentiated shock was 1.6% and 1.2%, respectively. There were 9.5% patients with multifactorial shock in the early stage and 14.4% in the middle stage. Totally 7 combinations of multifactorial shock were found in different stages after polytrauma. In the early stage, the combination of HS and DS accounted the highest ratio (42.3%) and followed by HS and OS for 28.8%. In the middle stage, the combination of HS and DS was the most common (48.6%) and followed by DS and OS (24.3%). Conclusions:The incidence of shock in polytrauma patients is high. Different types of shock can occur simultaneously or sequentially. Therefore a comprehensive resuscitation strategy is significant to improve the success rate of treatment.