Surgical separation of shared liver with cotton tourniquets in conjoined twins: simple and effective hemostasis

Objective

Surgical separation of the fused liver is extremely risky and sometimes life-threatening in conjoined twins because of the potential risks of hypovolemia and hemorrhagic shock.

Methods

Three pairs of symmetrical conjoined twins sharing fused livers were successfully separated by using a simple but effective local blockade measure without disturbing the portal circulation.

Results

The volume of intraoperative blood loss was minimal, and no major complications occurred. All the separated babies survived the procedure and remained healthy, both physically and mentally, after discharge. Two babies died of pneumonia associated with their preexisting cardiac defects.

Conclusions

Cotton tourniquets temporally and securely blocked the local blood supply to the narrow gap dissecting interface with minimal interference with the remaining segments, in addition to orienting the transection of the fused liver and minimizing blood loss from the liver dissection.     

Microsurgical treatment for 55 patients with hemifacial spasm due to cerebellopontine angle tumors

Tumor-related hemifacial spasm (HFS) has been found to be rare. During the period from October 1984 to October 2008, we treated 6,910 HFS patients using a microsurgical procedure. Of these HFS patients, 55 cases were associated with cerebellopontine angle tumors. A small craniectomy was performed in order to excise the tumor. All tumors were found to compress the root exit zone (REZ) of the facial nerve to different extents, but concomitant vascular compression of the facial nerve was observed in a majority of cases, and microvascular decompression of the facial nerve at REZ was conducted in 43 of 55 patients (78.2%) by displacing the co-compressing vasculature away from the REZ and retaining it using a Teflon pad. Intraoperative findings and postoperative pathological examinations suggested that the tumors were epidermoid cysts, meningiomas, and Schwannomas. Follow-up in 48 of 55 patients for 4–230 months after surgery showed that the clinical symptoms of HFS disappeared in 43 cases, improved in two cases, and recurred in three cases. Ten patients had sequelae associated with the operation. We concluded from this study that the majority of cases of tumor-related HFS are caused by combined tumor and vascular co-compression at the REZ, and tumor removal and microvascular decompression are required in order to relieve the symptoms.     

Effect of rifampicin on the risk of steroid‐induced osteonecrosis of the femoral head

Objective: To investigate the effects and possible mechanism of rifampicin on steroid‐induced osteonecrosis of the femoral head (ONFH). Methods: Bone marrow stromal cells (BMSC) separated from male rats were cultured in vitro without any treatment (Group mA), exposed to dexamethasone (Group mB), treated with rifampicin (Group mC), and exposed to dexamethasone and rifampicin simultaneously (Group mD) respectively (n = 5 in each group). After 7 days, P‐glycoprotein (P‐gp) activity and adipogenesis of the BMSC were evaluated. In an in vivo experiment, 80 rats were randomly divided into 4 groups (n= 20 in each group). Group A received intragastric saline for 5 weeks. Group B received intragastric saline for one week, followed by subcutaneous methylprednisolone and saline for 4 weeks. Group C received intragastric rifampicin for 5 weeks. Group D received intragastric rifampicin for one week, followed by subcutaneous methylprednisolone and rifampicin for 4 weeks. At the end of the experiment, all rats underwent analysis of P‐gp activity of BMSC, P‐gp expression in the femoral heads, MRI and histomorphometry of the femoral heads. Results: In vitro, the P‐gp activity of BMSC increased and lipid accumulation decreased significantly in Group mD, compared to Group mB. In vivo, P‐gp activity and P‐gp expression in Group D increased compared to Group B. The mean area of MRI abnormal signal, adipocytic variables and apoptotic cells in Group D decreased, mean percentage of the whole epiphysis made up by the epiphyseal ossification center and trabecular structure variables improved compared to those in Group B. The incidence of ONFH was lower in Group D (50%) than in Group B (80%). Conclusion: Rifampicin may decrease the risk of steroid‐induced ONFH by enhancing P‐gp activity, thus preventing steroid‐induced BMSC adipogenesis.     

Modulation of metabolic brain function by bilateral subthalamic nucleus stimulation in the treatment of Parkinson’s disease

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) was proposed as an effective way to improve the symptoms of Parkinson’s disease (PD). We studied metabolic modulation in the brain by bilateral STN stimulation using FDG PET. Five PD patients (age 61.6 ± 3.9 years) at advanced stage were scanned under OFF and ON conditions of stimulation. Network analysis was used to evaluate the effect of stimulation on the expression of an abnormal Parkinson’s disease-related spatial covariance pattern (PDRP). In addition, statistical parametric mapping was used to assess the effect of this intervention on regional glucose metabolism. We found that bilateral STN DBS led to a significant reduction (P < 0.02) in the PDRP network activity on an individual subject basis between OFF and ON conditions, parallel to significant improvement (P < 0.002) of clinical symptoms in these patients. The treatment also decreased glucose metabolism in the right lentiform nucleus and cerebellum, and in the bilateral ventral thalamus and precuneus, but increased metabolism in the left midbrain and pons. This was consistent with the notion that clinical benefit in a PD patient was associated with the suppression of hyperactive motor circuitry following STN stimulation. These findings suggest that DBS is more likely to function by regulating the entire neural network rather than merely exciting or inhibiting certain nuclei.     

Mechanistic contribution of ubiquitous 15-lipoxygenase-1 expression loss in cancer cells to terminal cell differentiation evasion

Loss of terminal cell differentiation promotes tumorigenesis. 15-Lipoxygenase-1 (15-LOX-1) contributes to terminal cell differentiation in normal cells. The mechanistic significance of 15-LOX-1 expression loss in human cancers to terminal cell differentiation suppression is unknown. In a screen of 128 cancer cell lines representing more than 20 types of human cancer, we found that 15-LOX-1 mRNA expression levels were markedly lower than levels in terminally differentiated cells. Relative expression levels of 15-LOX-1 (relative to the level in terminally differentiated primary normal human-derived bronchial epithelial cells) were lower in 79% of the screened cancer cell lines than relative expression levels of p16 (INK4A), which promotes terminal cell differentiation and is considered one of the most commonly lost tumor suppressor genes in cancer cells. 15-LOX-1 was expressed during terminal differentiation in three-dimensional air-liquid interface cultures, and 15-LOX-1 expression and terminal differentiation occurred in immortalized nontransformed bronchial epithelial but not in lung cancer cell lines. 15-LOX-1 expression levels were lower in human tumors than in paired normal lung epithelia. Short hairpin RNA-mediated downregulation of 15-LOX-1 in Caco-2 cells blocked enterocyte-like differentiation, disrupted tight junction formation, and blocked E-cadherin and ZO-1 localization to the cell wall membrane. 15-LOX-1 episomal expression in Caco-2 and HT-29 colon cancer cells induced differentiation. Our findings indicate that 15-LOX-1 downregulation in cancer cells is an important mechanism for terminal cell differentiation dysregulation and support the potential therapeutic utility of 15-LOX-1 reexpression to inhibit tumorigenesis.     

Screening for two SNPs of LINGO1 gene in patients with essential tremor or sporadic Parkinson's disease in Chinese population

Two markers rs9652490 and rs11856808 both located in intron 3 of the LINGO1 gene have been nominated recently to be associated with essential tremor (ET). Although ET and Parkinson's disease (PD) are considered as different entities, they have many overlapping clinical and pathological features. We aimed to evaluate the role of rs9652490 and rs11856808 in the development of ET and PD. To this point, we sequenced the region involving the two markers in 109 ET cases, 425 sporadic Parkinson's disease (SPD) cases and 430 controls in Chinese population. After stratification by age, the rs9652490G allele suggested protective role in the early onset PD (EOPD, age at onset ≤50 years) group compared with age matched controls (OR = 0.56, 95% CI: 0.35–0.90, p = 0.015). No other significant association was found. We concluded that the two markers rs9652490 and rs11856808 were not strongly related to the development of ET or late onset SPD, but the rs9652490G allele might be a protective factor for EOPD in Chinese population.     

Glutamate transporter type 3 knockout mice have a decreased isoflurane requirement to induce loss of righting reflex

Excitatory amino acid transporters (EAAT) uptake extracellular glutamate, the major excitatory neurotransmitter in the brain. EAAT type 3 (EAAT3), the main neuronal EAAT, is expressed widely in the CNS. We have shown that the volatile anesthetic isoflurane increases EAAT3 activity and trafficking to the plasma membrane. Thus, we hypothesize that EAAT3 mediates isoflurane-induced anesthesia. To test this hypothesis, the potency of isoflurane to induce immobility and hypnosis, two major components of general anesthesia, was compared in the CD-1 wild-type mice and EAAT knockout mice that had a CD-1 strain gene background. Hypnosis was assessed by loss of righting reflex in this study. The expression of EAAT1 and EAAT2, two widely expressed EAATs in the CNS, in the cerebral cortex and spinal cord was not different between the EAAT3 knockout mice and wild-type mice. The concentration required for isoflurane to cause immobility to painful stimuli, a response involving primarily reflex loops in the spinal cord, was not changed by EAAT3 knockout. However, the EAAT3 knockout mice were more sensitive to isoflurane-induced hypnotic effects, which may be mediated by hypothalamic sleep neural circuits. Interestingly, the EAAT3 knockout mice did not have an altered sensitivity to the hypnotic effects caused by ketamine, an i.v. anesthetic that is a glutamate receptor antagonist and does not affect EAAT3 activity. These results suggest that EAAT3 modulates the sensitivity of neural circuits to isoflurane. These results, along with our previous findings which suggests that isoflurane increases EAAT3 activity, indicate that EAAT3 may regulate isoflurane-induced behavioral changes, including anesthesia.     

Conditional Gene Expression in the Mouse Inner Ear Using Cre-<Emphasis Type="Italic">loxP</Emphasis>

In recent years, there has been significant progress in the use of Cre-loxP technology for conditional gene expression in the inner ear. Here, we introduce the basic concepts of this powerful technology, emphasizing the differences between Cre and CreER. We describe the creation and Cre expression pattern of each Cre and CreER mouse line that has been reported to have expression in auditory and vestibular organs. We compare the Cre expression patterns between Atoh1-CreER^TM and Atoh1-CreER^T2 and report a new line, Fgfr3-iCreER^T2, which displays inducible Cre activity in cochlear supporting cells. We also explain how results can vary when transgenic vs. knock-in Cre/CreER alleles are used to alter gene expression. We discuss practical issues that arise when using the Cre-loxP system, such as the use of proper controls, Cre efficiency, reporter expression efficiency, and Cre leakiness. Finally, we introduce other methods for conditional gene expression, including Flp recombinase and the tetracycline-inducible system, which can be combined with Cre-loxP mouse models to investigate conditional expression of more than one gene.     

Mechanisms of the cerebral vasodilator actions of isoflavonoids of Gegen on rat isolated basilar artery

Ethnopharmacological relevance

Gegen (root of Pueraria lobata) is used in traditional Chinese medicine for treatment of cardiovascular diseases. In this study, the relaxant actions of three of its isoflavonoids; puerarin, daidzein, and daidzin, were investigated on rat-isolated cerebral basilar artery.

Materials and methods

Rat basilar artery rings were precontracted with 100 nM U46619. Involvement of endothelium-dependent mechanisms was investigated by mechanical removal of the endothelium and inhibitors of nitric oxide synthase (NOS) and cyclooxygenase (COX) enzymes. Adenylyl cyclase- and guanylyl cyclase-dependent pathways were investigated using their respective inhibitors 9-(tetrahydro-2-furanyl)-9H-purine-6-amine (SQ22536) and 1H-[1,2,4]oxadiazolo [4,3-[alpha]]-quinoxalin-1-one (ODQ). K⁺ channels were investigated by pretreatment of the artery rings with various K⁺ channel inhibitors, and Ca²⁺ channels were investigated in artery rings incubated with Ca²⁺-free buffer and primed with 100 nM U46619 for 5 min prior to adding CaCl₂ to elicit contraction.

Results

Puerarin, daidzein, and daidzin produced concentration-dependent relaxation of the artery rings with concentration that produced 50% inhibition (IC₅₀) of 304 ± 49 μM, 20 ± 7 μM, and 140 ± 21 μM, respectively. Removal of the endothelium produced no change on their vasorelaxant responses except the maximum response (I_max) to puerarin was inhibited by 28%. The NOS inhibitor N^G-nitro-l-arginine methyl ester (L-NAME; 100 μM) also produced 45% inhibition on the puerarin-induced vasorelaxant response, but not the COX inhibitor flurbiprofen (10 μM). SQ22536 (100 μM) and ODQ (100 μM) did not affect the vasodilator responses to puerarin, daidzein and daidzin, but glibenclamide (1 μM), tetraethylammonium (TEA, 100 mM) or a combination of K⁺ channel inhibitors (100 nM iberiotoxin + 1 mM 4-aminopyridine + 100 μM barium chloride + 1 μM glibenclamide + 100 mM TEA) reduced their I_max. The contractile response to CaCl₂ was attenuated by 61% and 34% in the presence of daidzein and daidzin, respectively, whereas, puerarin did not significantly affect the contraction.

Conclusions

The vasorelaxant action of daidzein and daidzin involved opening of K⁺ channels and inhibition of Ca²⁺ influx in the vascular smooth muscle cells. There is no evidence supporting involvement of endothelium-derived relaxing factors (EDRFs) in their actions. In contrast, puerarin produced vasodilatation via an endothelium-dependent mechanism involving nitric oxide production and an endothelium-independent pathway mediated by the opening of K⁺ channels. The cerebral vasodilator activities of all these three isoflavonoids may be beneficial to patients with obstructive cerebrovascular diseases.     

不同麻醉方法对老年肿瘤患者术后认知功能的影响

目的观察全凭静脉全身麻醉和静吸复合全身麻醉对老年肿瘤患者术后认知功能的影响。方法选择80例行择期外科手术的老年肿瘤患者,随机分为A、B 2组各40例,A组行全凭静脉全身麻醉,B组行静吸复合全身麻醉,手术中麻醉深度维持于脑电双频指数(BIS)40～55。记录患者术后苏醒情况及气管导管拔管后1,6,12及24 h的MMSE评分。结果 2组患者术后苏醒时间、拔管时间、拔管后话语时间比较无显著性差异(P均>0.05);拔管后,A组患者1 h的MMSE评分低于术前(P<0.05),6 h MMSE评分恢复至术前水平;B组患者1,6 h的MMSE评分低于术前(P<0.05),12 h MMSE评分恢复至术前水平。2组患者拔管后1,12及24 h的MMSE评分比较无显著性差异(P>0.05),但B组6 h的MMSE评分低于A组同时点MMSE分值(P<0.05)。结论维持BIS于合适深度的全凭静脉全身麻醉和静吸复合全身麻醉对老年肿瘤术后近期认知功能影响较小,全凭静脉麻醉术后认知功能恢复要快于静吸复合麻醉。