Intra-arterial Contrast-enhanced Micro-computed Tomography Can Evaluate Intracranial Status in the Ultra-early Phase of Experimental Subarachnoid Hemorrhage in Rats

The endovascular perforation (EP) model is a common technique for experimental subarachnoid hemorrhage (SAH) in rats, simulating the pathophysiological features observed in the acute phase of SAH. Due to the drawbacks of large variations in the amount of bleeding, the results obtained from this model require severity evaluation. However, no less-invasive procedure could confirm the precise intracranial conditions immediately after establishing the rat EP model. We created a novel method for evaluating SAH immediately after establishing the rat EP model using intra-arterial contrast-enhanced micro-computed tomography (CT). We administered contrast agents continuously via the carotid artery during surgery and performed CT examination immediately after SAH induction. First, bleeding severity was classified by establishing a scoring system based on the CT findings (cSAH scoring system). Subsequently, we determined the actual SAH distribution macroscopically and histologically and compared it with the cSAH scores. Second, we investigated the contrast agent’s neurotoxicity in rats. Finally, we confirmed the correlation between cSAH scores and SAH severity, including neurological status, cerebral vasospasm, and hematoma volume 24 hr after SAH. Intra-arterial contrast-enhanced micro-CT could visualize the distribution of SAH proportionally to the bleeding severity immediately after establishing the EP model. Moreover, the contrast agent administration was determined not to be neurotoxic to rats. The cSAH scoring revealed a significant correlation with the SAH severity in the rat EP model (P <0.01). Thus, our minimally invasive method provided precise information on intracranial status in the ultra-early phase of SAH in rats EP model.     

Effect of Subarachnoid Bupivacaine Block on Anesthetic Requirements for Thiopental in Rats

Background: Subarachnoid bupivacaine blockade has been reported to reduce thiopental and midazolam hypnotic requirements in patients. The purpose of this study was to examine if local anesthetically induced lumbar intrathecal blockade would reduce thiopental requirements for blockade of motor responses to noxious and nonnoxious stimuli in rats.

Methods: After intrathecal and external jugular catheter placement, rats were assigned randomly to two groups in a crossover design study, with each rat to receive either 10 micro liter of 0.75% bupivacaine or 10 micro liter of normal saline intrathecally. The doses of intravenously administered thiopental required to ablate the eyelid reflex, to block the withdrawal reflex of a front limb digit, and to block the corneal reflex were compared. In two separate groups of animals, hemodynamic parameters and concentrations of thiopental in the brain were compared between intrathecally administered bupivacaine and saline.

Results: The thiopental dose required to block the described responses was decreased with intrathecally administered bupivacaine versus intrathecally administered saline from (mean +/- SD) 40 +/- 5 to 24 +/- 4 mg/kg (P < 0.001) for the eyelid reflex, from 51 +/- 6 to 29 +/- 6 mg/kg (P < 0.005) for front limb withdrawal, and from 67 +/- 8 to 46 +/- 8 mg/kg (P < 0.01) for the corneal reflex. The concentration of thiopental in the brain at the time of corneal reflex blockade for the group given bupivacaine was significantly lower than in the group given saline (24.1 vs. 35.8 micro gram/g, P = 0.02).     

Liposome-Encapsulated Hemoglobin Reduces the Size of Cerebral Infarction in Rats: Effect of Oxygen Affinity

Liposome-encapsulated hemoglobin (LEH) with a low oxygen affinity (l-LEH, P ₅₀ = 45 mm Hg) was found to be protective in the rodent and primate models of ischemic stroke. This study investigated the role of LEH with a high O₂ affinity (h-LEH, P ₅₀ = 10 mm Hg) in its protective effect on brain ischemia. The extent of cerebral infarction was determined 24 h after photochemically induced thrombosis of the middle cerebral artery from the integrated area of infarction detected by triphenyltetrazolium chloride staining in rats receiving various doses of h-LEH as well as l-LEH. Both h-LEH and l-LEH significantly reduced the extent of cortical infarction. h-LEH remained protective at a lower concentration (minimal effective dose [MED]: 0.08 mL/kg) than l-LEH (MED: 2 mL/kg) in the cortex. h-LEH reduced the infarction extent in basal ganglia as well (MED: 0.4 mL/kg), whereas l-LEH provided no significant protection. h-LEH provided better protection than l-LEH. The protective effect of both high- and low-affinity LEH may suggest the importance of its small particle size (230 nm) as compared to red blood cells. The superiority of h-LEH over l-LEH supports an optimal O₂ delivery to the ischemic penumbra as the mechanism of action in protecting against brain ischemia and reperfusion.     

Effect of Vasoconstrictive Agents Added to Lidocaine on Intravenous Lidocaine-induced Convulsions in Rats

Background: Epinephrine is reported to decrease the threshold of intravenous lidocaine-induced convulsions. However, the mechanism underlying this effect is not clear. Therefore, we carried out a study to examine the role of vasopressor-induced hypertension.

Methods: Fifty-six awake Wistar rats were assigned to seven groups of eight. All groups received a continuous intravenous infusion of lidocaine at a rate of 4 mg *symbol* kg sup -1 *symbol* min sup -1 until generalized convulsions occurred. The control group (group C) received plain lidocaine. The acute hypertensive groups received lidocaine with epinephrine (group E), norepinephrine (group N), or phenylephrine (group P) to increase mean arterial blood pressure (MAP) to 150 plus/minus 5 mm Hg. Sodium nitroprusside (SNP) was added to prevent an increase in mean arterial pressure in the remaining three groups (vasopressor-SNP groups).

Results: The acute hypertensive groups required significantly smaller cumulative doses of lidocaine to produce convulsions compared with control (C - 41.5 plus/minus 2.9 > E - 24.1 plus/minus 2.7, N = 27.1 plus/minus 2.8, P = 26.7 plus/minus 2.5 mg *symbol* kg sup -1; values are mean plus/minus SD, P < 0.01) In addition, plasma lidocaine concentrations (C = 11.0 plus/minus 0.7 > E = 7.4 plus/minus 0.5, N = 7.9 plus/minus 0.6, P = 8.1 plus/minus 0.8 micro gram *symbol* ml sup -1, P < 0.01) and brain lidocaine concentrations (C = 50.9 plus/minus 4.5 > E = 32.6 plus/minus 4.2, N - 34.5 plus/minus 4.8, P - 37.1 plus/minus 4.5 micro gram *symbol* g sup -1, P < 0.01) were less in the acute hypertensive groups at the onset of convulsions. In the vasopressor-SNP groups, the plasma and brain lidocaine concentrations at the onset of convulsions returned to the control values, although epinephrine and norepinephrine, but not phenylephrine, still decreased cumulative convulsant doses of lidocaine significantly (P < 0.01) compared with control (E + SNP = 30.8 plus/minus 2.9 < N + SNP = 34.8 plus/minus 2.8, P < 0.01) < P + SNP = 40.2 plus/minus 3.0 mg *symbol* kg sup -1, P < 0.01). The brain/plasma concentration ratios were similar for the seven groups.     

Changes in the Coagulation and Fibrinolytic System of Patients with Subarachnoid Hemorrhage

The aim of this study was to investigate the dynamic changes in the coagulation and fibrinolytic system with subarachnoid hemorrhage. The blood coagulation enzyme-AT complex (TAT), anticoagulant enzyme (AT), tissue plasminogen activator (tPA), plasminogen activin inhibitor (PAI-1), and mean blood flow velocity were measured. The TAT level was significantly higher 6 h after subarachnoid hemorrhage (SAH), whereas AT was significantly lower. These changes were maintained at 12 h to 1 d after SAH, returned to normal at 3 d, significantly changed again at 7 d to 14 d. The tPA level gradually increased after SAH and peaked at 14 d, and then returned to normal at 21 d. The PAI-1 levels were significantly lower than those in the control group 1 d after SAH gradually increased, and returned to normal at 21 d. In the cerebral vasospasm (CVS) groups, the levels of TAT, and AT significantly changed compared to the non-CVS groups after SAH. The PAI-1 levels were higher at 7 d and 14 d, but the changes were not significant. In groups Fisher III and IV as well as Hunt III to V, the TAT, AT, tPA, and PAI-1 levels were significantly higher than those in both Fisher and Hunt I and II 6 h, 12 h, 1 d, 7 d, and 14 d after SAH. The changes in the coagulation and fibrinolytic system of patients with SAH are correlated with the progress and symptoms of SAH as well as the blood content and CVS.     

氯沙坦对实验性糖尿病大鼠肾脏的炎症抑制作用

目的：观察氯沙坦对糖尿病大鼠肾脏的炎症抑制作用。方法：采用链脲佐菌素（streptomtoein，STZ）65mg／kg腹腔注射建立糖尿病大鼠模型。试验分正常对照组、模型组、治疗组，后一组于模型成功后1周给予氯沙坦20mg／kg灌胃，共12周。分别测定3组24h尿蛋白排泄量、血肌酐、肾重／体重、血浆C反应蛋白（CRP）及肿瘤坏死因子-α（TNF-α）水平；观察肾脏病理形态学变化；应用免疫组化法检测肾组织T011样受体4（TLR4）、核因子-κB（NF-κB）的蛋白表达；RT-PCR检测肾组织TLR4的核酸表达。结果：模型组与对照组相比：模型组大鼠24h尿蛋白、血肌酐、尿素氮、肾重／体重明显升高，肾小球肥大，细胞增生，PAS阳性物质沉积增多；血CRP、TNF-α含量及肾组织TLR4、NF-κB的表达明显增加。经氯沙坦治疗后大鼠血CRP、TNF-α含量下降，肾组织TLR4、NF-κB的表达亦减弱，治疗前后比较存在差异（P〈0．05）。结论：氯沙坦对糖尿病肾病具有保护作用，其作用机制还可能是通过下调NF-κB、TLR4的表达，降低血浆CRP、TNF-α含量，抑制炎症反应而减少糖尿病肾病损伤。     

Elderly Patients on Chronic Hemodialysis with Hyperparathyroidism: Increase of Hemoglobin Level after Intravenous Calcitriol

In patients on chronic hemodialysis (CHD), hyperparathyroidism (HPTH) is associated with anemia and resistance to erythropoietin (EPO). In the last few years, calcitriol intravenously (IV) has been used with success in the treatment of the HPTH, secondary to chronic renal failure. However, the effects of calcitriol on the hematological parameters of these patients have never been well evaluated. This study included 11 elderly CHD patients (f = 6, m = 5; mean age = 73.6 years, mean time on CHD = 42.8 months) with HPTH under EPO therapy (IV). They were treated for 12 months with calcitriol IV (mean dose=2.33 mcg/pt/week). Patients with iron deficiency anemia (ferritin < 200 ng/ml) were excluded. The patients were compared before and after 12 months of calcitriol treatment, with respect to several laboratory parameters and with respect to EPO dose. A paired t-test was used. After treatment, we found a decrease of PTH (634 vs. 418 pg/ml, P = 0.029); the serum calcium increased (8.8 vs. 9.9 mg/dl, P = 0.002); no differences were noted in the plasma levels of alkaline phosphatase, phosphorous, BUN, creatinine, Na and K. Mean levels of Hb (10.2 vs. 11.4 g/dl, P = 0.004) and the Hct (30 vs. 34.3, P = 0.004) increased after 12 months of calcitriol; the levels of serum iron (70 vs. 78 μg/dl, P = ns) and ferritin (531 vs. 785 ng/ml, P = ns) and the EPO dose (105 vs. 100 U/kg/week, P = ns) were similar before and after treatment. Our data show that the treatment of HPTH in CHD elderly patients with calcitriol can increase Hb level without increasing EPO dose.     

Effect of Postoperative Irradiation on Free Skin Flaps: An Experimental Study in Rats

The modern treatment of musculoskeletal malignant tumours often requires different combinations of surgery, chemotherapy, and radiotherapy. Although combination treatments have allowed reconstruction of more complex defects, the risk of complications also rises. In clinical series the complication rate is influenced by the characteristics of the defect and the quality of the radiation used. The flap survival is high, but the overall complication rate is more than 25%. In this study we looked at the healing of microvascular free skin flaps exposed to postoperative irradiation in a rat model. Epigastric microvascular free skin flap were exposed to a single dose of 20 Gy radiation one week postoperatively ( n = 8). A comparison was made with free epigastric skin flaps without postoperative radiation ( n = 8). The healing was assessed histologically at four weeks and by measuring the tensile strength of the wound. Biochemical total nitrogen and hydroxyproline contents were also measured. Results showed that histologically the interfaces healed similarly with only minimal histomorphological changes. Neither the mechanical strength of the healing interface nor the biochemical markers altered significantly. Postoperative irradiation with a single dose of 20 Gy does not affect the survival of free skin flaps in rats. In the future the model described could be used to study the effects of combination therapy of surgery, radiotherapy, and chemotherapy more closely to find the optimal control of malignancies with limited damage to treated tissue.     

Epidemiology of Subarachnoid Hemorrhage in Isolated Islands in Japan: A Population-based Study in the Miyako Islands

The Miyako Islands (with a population of approximately 50,000) are located in southwestern Japan, with a subtropical oceanic climate. This isolated location permitted a retrospective population-based epidemiological study of subarachnoid hemorrhage. We retrospectively enrolled 110 consecutive patients from 2010 to 2019 using the subarachnoid hemorrhage database at Okinawa Miyako Hospital, which is the only local facility with neurosurgeons. We calculated the incidence of subarachnoid hemorrhage standardized to the entire Japanese population. The seasonal distribution of subarachnoid hemorrhage onset and patients'' epidemiological characteristics were also investigated. The standardized annual incidence of subarachnoid hemorrhage was 21.4 per 100,000 population, as reported previously in Japan. The patients'' mean age was 62.1 ± 15.4 years, and women constituted 60.9%. Anterior communicating artery aneurysms were most common. The endovascular treatment for ruptured aneurysms was increasing as standard levels in Japan. The rates of symptomatic vasospasm and secondary hydrocephalus requiring additional neurosurgical treatment were 2.7% and 19.1%, respectively. The mortality rate was 23.6%. The percentage of patients with a modified Rankin scale score of 0-2 at discharge was 55.5%. There were no differences in the frequency of subarachnoid hemorrhage associated with seasonal distribution or climatic factors. The incidence, baseline characteristics, and clinical outcomes of subarachnoid hemorrhage in the Miyako Islands were similar to those in other regions of Japan. There are preferable epidemiological backgrounds for further practical clinical research.     

Effects of Intracisternal Methylprednisolone on Lipid Peroxidation in Experimental Subarachnoid Haemorrhage

Summary  The efficacy of intracisternal methylprednisolone was examined on lipid peroxidation in a canine subarachnoid haemorrhage (SAH) model. The concentration of lipid peroxides increased significantly in the cerebrospinal fluid (CSF) supernatant on Day 4, and also in the arterial wall on Day 7. Intracisternal administration of methylprednisolone reduced markedly the products of lipid peroxidation both in CSF and in the arterial wall. The findings suggest that lipid peroxidation might play a significant role in the genesis of vasospasm after SAH, and that direct administration of methylprednisolone into the subarachnoid space might reduce lipid peroxides in the arterial wall and so influence the prevention of vasospasm.     

静脉留置针肝素封管液对患者出凝血功能影响的探讨

为探讨肝素钠生理盐水(50 U/ml,2ml)封管对患者出凝血机制的影响,对35例凝血功能正常,使用一次性静脉留置针输液的患者于留针前及留针(5.54±2.04)d拔针后,分别进行血小板聚集试验(PAGT)、凝血酶原时间(PT)、血浆凝血酶时间(TT)及部分凝血活酶时间(APTT)测定.结果拔针后患者的PAGT较留置前明显降低,经t检验,P＜0.05,但仍与正常水平接近,而PT、TT、APTT封管前后的变化无显著性差异,P＞0.05;所有患者均未发生出血倾向.说明出凝血机制正常者(脑出血急性期除外)使用稀释肝素液封管留置输液是安全的.     

血必净对局灶节段性肾小球硬化大鼠的肾脏保护作用

目的：观察中药血必净注射液对局灶节段性肾小球硬化症（FSGS）大鼠转化生长因子-β1（TGF-β1）和血管内皮生长因子（VEGF）表达的影响，探讨血必净对FSGS大鼠的肾脏保护作用。方法：建立单侧肾切除加重复注射阿霉素的FSGS大鼠模型，分为血必净组、模型组，并设假手术组为对照组。检测各组大鼠第0、4、6、8周24h尿蛋白定量及血生化值，计算内生肌酐清除率（Ccr）；对肾组织进行病理形态学观察，计算肾小球硬化指数（SI）、肾小球细胞外基质与肾小球面积之比（ECM／GA），采用免疫组织化学方法检测肾组织TGF-β1、VEGF的表达。结果：与模型组相比，血必净治疗组大鼠尿蛋白排泄减少，肾脏病理改变明显减轻，肾组织TGF-β1、VEGF的表达减少。结论：血必净可以抑制局灶节段性肾小球硬化大鼠肾组织TGF-β1、VEGF的高表达，具有一定的肾脏保护作用。     

Effect of Full-Thickness Skin Graft Initial Dimension on Secondary Wound Contraction: Experimental Study in Rats

BACKGROUND: The size of a full-thickness skin graft (FTSG) is typically determined using a pattern of the defect usually obtained following excision of a skin lesion. OBJECTIVE: The aim of this experimental study is to investigate the effects of various graft sizes on secondary wound contraction. METHODS: Four 2.5 x 2.5 cm defects were created on the backs of 20 rats. Defect A was left to heal by secondary intention. The graft obtained from defect B (exact size graft) was sutured to its original bed. The wound of defect C (large graft) was patterned, and this was used to obtain a generous graft from the abdomen. A presized 1.5 x 1.5 graft obtained from defect D (small graft) was sutured to its original wound. Graft areas on days 0, 3, 7, 10, 14, 18, and 21 were calculated and converted into a percentage of the original wound size. Analysis of variance was used for statistical comparison. Open wounds reached a final wound size of 5% at day 21. Exact-size grafts showed the least secondary contraction rate (74.19 +/- 4.30 %) (p < .05). CONCLUSION: A graft in the size of a planned excision preserves its original area better than grafts larger or smaller in size in the rodent model. The size of a FTSG is an important factor in preventing secondary wound contraction. However, it should be stressed that the results of this study cannot necessarily be extrapolated to real clinical scenarios without further detailed studies.     

Rapid Induction of Meningeal Collagen Synthesis in the Cerebral Cisternal and Ventricular Compartments after Subarachnoid Hemorrhage

Summary. Procollagen propeptides in the lumbar CSF increase after subarachnoid hemorrhage (SAH), and elevated concentrations have been detected as early as on day 8. We studied here the timing and localization of the induction of meningeal collagen synthesis during the first week after SAH by analysing cisternal and ventricular CSF samples. We obtained 29 cisternal and 10 ventricular CSF samples at operation from patients with SAH between days 1 and 9 after onset. The carboxyterminal propeptide of type I procollagen (PICP) and the aminoterminal propeptide of type III procollagen (PIIINP) were measured using radio-immunoassays. The concentrations of PICP and PIIINP in the cisternal CSF were elevated as early as on day 2 after SAH. PICP increased in a sigmoidal fashion (R²=0.39, p<0.001), while PIIINP increased linearly (R²=0.28, p=0.003) and was approximately 3-fold higher on day 9 than initially. PICP was twice as high (p=0.02) in the cisternal than in the ventricular CSF after SAH and PIIINP was 4-times higher (p=0.007). Interestingly, the concentrations were similar in a patient with intraventricular bleeding. The cisternal compartment contributed to the propeptides in the CSF more than did the ventricular compartment, but the latter also appeared to have a definite potential for fibroproliferative reaction. Meningeal collagen synthesis was induced rapidly within the first few days after SAH suggesting that therapeutic attempts to inhibit the fibroproliferative reaction should be started as early as possible.