Exploring the molecular biology of ischemic cardiomyopathy based on ferroptosis‑related genes

Ischemic cardiomyopathy (ICM) is a serious cardiac disease with a very high mortality rate worldwide, which causes myocardial ischemia and hypoxia as the main damage. Further understanding of the underlying pathological processes of cardiomyocyte injury is key to the development of cardioprotective strategies. Ferroptosis is an iron-dependent form of regulated cell death characterized by the accumulation of lipid hydroperoxides to lethal levels, resulting in oxidative damage to the cell membrane. The current understanding of the role and regulation of ferroptosis in ICM is still limited, especially in the absence of evidence from large-scale transcriptomic data. Through comprehensive bioinformatics analysis of human ICM transcriptome data obtained from the Gene Expression Omnibus database, the present study identified differentially expressed ferroptosis-related genes (DEFRGs) in ICM. Subsequently, their potential biological mechanisms and cross-talk were analyzed, and hub genes were identified by constructing protein-protein interaction networks. Ferroptosis features such as reactive oxygen species generation, changes in ferroptosis marker proteins, iron ion aggregation and lipid oxidation, were identified in the H9c2 anoxic reoxygenation injury model. Finally, the diagnostic ability of Gap junction alpha-1 (GJA1), Solute carrier family 40 member 1 (SLC40A1), Alpha-synuclein (SNCA) were identified through receiver operating characteristic curves and the expression of DEFRGs was verified in an in vitro model. Furthermore, potential drugs (retinoic acid) that could regulate ICM ferroptosis were predicted based on key DEFRGs. The present article presents new insights into the role of ferroptosis in ICM, investigating the regulatory role of ferroptosis in the pathological process of ICM and advocating for ferroptosis as a potential novel therapeutic target for ICM based on evidence from the ICM transcriptome.

[Clinical characteristics of a case of severe pneumonia caused by coinfection of COVID-19 and Chlamydia Psittaci]

A 69-year-old female patient was admitted to the Department of Respiratory and Critical Care Medicine, Affiliated Hospital of Xuzhou Medical University due to a "cough and fever for eight days". On admission, a coronavirus disease (COVID-19) nucleic acid test was positive, and a chest CT scan showed progressive patchy shadows and consolidation shadows in both lungs. Arterial blood gas analysis showed type Ⅰ respiratory failure. The primary diagnosis was severe community-acquired pneumonia in an older adult without underlying disease. However, oxygen inhalation, steroid, anti-inflammatory, and antibacterial empirical treatment with piperacillin/tazobactam was ineffective. Metagenomic next-generation sequencing of bronchoscopy alveolar lavage fluid showed Chlamydia psittaci(C. psittaci). Severe pneumonia was confirmed, caused by coinfection with severe acute respiratory syndrome coronavirus 2 and C. psittaci. A combination of doxycycline and moxifloxacin significantly improved the targeted and symptomatic treatment of the underlying cause. After discharge, the patient recovered within four weeks of follow-up. Therefore, clinicians should be alert to the possibility of coinfection of C. psittaci in patients already diagnosed with COVID-19.

[Toll-like receptors link atopic march and hygiene hypothesis]

The atopic march reveals that infants with atopic dermatitis are prone to food allergy, allergic rhinitis and asthma later in life. The hygiene hypothesis holds that the cleaner the personal hygiene and environment, the higher the incidence rate of asthma and allergy. It is believed that Toll like receptors (TLRs) are the bridge between innate immunity and adaptive immunity, playing an important role in inflammatory and immune diseases. More and more evidence shows that TLRs, involved in the pathophysiology of atopic march, connect atopic march with hygiene hypothesis as a potential therapeutic target for asthma and allergy.

Magnonic Unidirectional Spin Hall Magnetoresistance in a Heavy-Metal-Ferromagnetic-Insulator Bilayer

We report the observation of the unidirectional spin Hall magnetoresistance (USMR), which depends on the current or magnetization direction, in heavy-metal-ferromagnetic-insulator bilayer, Pt-Y_{3}Fe_{5}O_{12} (YIG). This USMR is apparently not caused by the mechanisms established in metallic bilayer, in which the ferromagnetic layer is required to be electrically conductive. From the magnetic field, current, temperature, and YIG thickness dependent measurements, the USMR is attributed to the asymmetric magnon creation and annihilation induced by the spin-orbit torque. This asymmetry and the resultant USMR are further revealed by the micromagnetic simulations combined with the spin-orbit torque and the spin drift-diffusion model. Our finding exhibits a nonlinear manipulation of magnons with the charge current.

[Evaluation of kurtosis on hearing loss caused by non-steady state noise in general equipment manufacturing industry]

Objective: To study the effect of occupational exposure to non-steady state noise on hearing loss in the general equipment manufacturing industry, and to explore the feasibility of applying kurtosis index to evaluate hearing loss caused by non-steady state noise. Methods: A total of 233 workers exposed to non-steady state noise in 6 general equipment manufacturing enterprises were selected as the observation group, and 237 workers exposed to steady noise in 4 textile enterprises were selected as the control group between 2012 and 2018. Personal normalized continuous A-weighted sound pressure level equivalent to an 8 h-working-day (L(Aeq, 8 h)) was determined by a noise dosimeter. Cumulation noise exposure (CNE) was calculated from L(Aeq, 8 h) and related working age, and the CNE was adjusted by using noise kurtosis (CNE' after adjustment) . Meanwhile, questionnaires and hearing loss tests were performed for all subjects. The changes in the threshold of high-frequency hearing and the incidence of high-frequency hearing loss caused by noise in the two groups were compared before and after the adjustment of the kurtosis of CNE. The correlation between CNE and the incidence of high-frequency hearing loss before and after kurtosis adjustment was analyzed. Results: There was an difference between the 3000-8000 Hz hearing threshold of workers in different CNE groups (P<0.05) . logistic regression analysis showed that CNE was a risk factor of high-frequency hearing loss for workers in the observation group (OR=1.189, P<0.05) , and trend Chi-square test showed that the incidence of high-frequency hearing loss increased with CNE levels (χ(2)(trend)=34.415, P<0.05) .Before the kurtosis adjustment, in the CNE 95~<110 dB (A) ·year level group, the incidence of high-frequency hearing loss and the high-frequency hearing threshold in the observation group were significantly higher than those in the control group (P<0.05) . After kurtosis adjustment, there was no significant difference in the incidence of high-frequency hearing loss between the observation group and the control group in each level group (P>0.05) . The correlation between CNE after kurtosis adjustment and the incidence of high-frequency hearing loss was better than that before adjustment (after R(2) adjustment >before R(2) adjustment) . Conclusion: The effect of non-steady state noise on high-frequency hearing loss of workers in general equipment industry increases with the increase of CNE, and the effect of non-steady state noise on high-frequency hearing loss of workers is greater than that of steady noise. CNE' can be used to evaluate the hearing loss caused by non-steady state noise.

[Dose-response relationship between noise kurtosis and noise-induced hearing loss]

Objective: To analyse the dose-response relationships between the kurtosis metric of noise and noise-induced hearing loss (NIHL) and study the role of kurtosis in the evaluation of NIHL associated with non-Gaussian noise. Methods: From January 2012 to December 2017, a total of 1869 workers in seven manufacturing industries were selected as the study subjects. The basic data of the workers were investigated by questionnaire, personal noise waveform was collected for a long time, and pure tone hearing threshold was tested. The 8-hour continuous equivalent A sound level (L(Aeq, 8 h)) , cumulative noise exposure (CNE) and kurtosis structure indexes were calculated. The dose-response relationships between kurtosis and NIHL were analyzed by stratification analysis method, which controlled the influence of CNE, L(Aeq, 8 h), exposure duration, age and sex on hearing loss using high-frequency noise-induced permanent threshold shift (NIPTS(346)) and high-frequency noise-induced hearing loss (HFNIHL) as outcome indicators. Results: When CNE was <90 dB (A) ·year and ≥100 dB (A) ·year, NIPTS(346) in the extremely high kurtosis group was significantly greater than that in the Gaussian kurtosis, low kurtosis and medium kurtosis group (P<0.05) . In the workers exposed to L(Aeq, 8 h)<85 dB (A) and ≥94 dB (A) , NIPTS(346) in the extremely high kurtosis group was significantly greater than that in the Gaussian kurtosis group (P<0.05) . Among workers under the age of 50 or male workers, NIPTS(346) in the extremely high kurtosis group was significantly greater than that in the Gaussian kurtosis, low kurtosis and medium kurtosis group (P<0.05) . Kurtosis was positively correlated with NIPTS(346) (r=0.121, P<0.05) . When CNE was <100 dB (A) ·year, the detection rate of HFNIHL increased with the increase of kurtosis level (P<0.01) . Logistic regression analysis showed that kurtosis was an important influencing factor for HFNIHL (OR=1.321) . Conclusion: Kurtosis has a dose-response relationship with the detection rate of HFNIHL in noise exposed workers, and noise kurtosis is an influencing factor of NIHL.

Unidirectional Spin-Wave-Propagation-Induced Seebeck Voltage in a PEDOT:PSS/YIG Bilayer

We clarify the physical origin of the dc voltage generation in a bilayer of a conducting polymer film and a micrometer-thick magnetic insulator Y_{3}Fe_{5}O_{12} (YIG) film under ferromagnetic resonance and/or spin wave excitation conditions. The previous attributed mechanism, the inverse spin Hall effect in the polymer [Nat. Mater. 12, 622 (2013)NMAACR1476-112210.1038/nmat3634], is excluded by two control experiments. We find an in-plane temperature gradient in YIG which has the same angular dependence with the generated voltage. Both vanish when the YIG thickness is reduced to a few nanometers. Thus, we argue that the dc voltage is governed by the Seebeck effect in the polymer, where the temperature gradient is created by the nonreciprocal magnetostatic surface spin wave propagation in YIG.

The Stupp regimen preceded by early post-surgery temozolomide versus the Stupp regimen alone in the treatment of patients with newly diagnosed glioblastoma multiforme (GBM)

2022

Background: In treatment of newly diagnosed GBM with the Stupp chemo-radiotherapy regimen, following by adjuvant chemotherapy, patients were treated with temozolomide (TMZ) & combined radiotherapy 4-5 weeks after surgery. In the interval between surgery and chemo-radiotherapy, it is not known whether additional TMZ treatment will improve efficacy or safety. This trial evaluated the safety and efficacy of the Stupp regimen + early post-surgery TMZ chemotherapy in the treatment of patients with newly diagnosed GBM. Methods: The trial was a multi-center, randomized open-label study. 99 newly diagnosed GBM patients were enrolled and randomly assigned to the Stupp regimen + early post-surgery TMZ chemotherapy arm (experimental group, n = 52) or to Stupp regimen alone (control group, n = 47). Fourteen days after surgery, the patients in experiment group recieved TMZ orally at 75mg/m2/day for 14 days. The primary endpoint of the study was the overall survival (OS). The secondary endpoints included the progression-free survival (PFS), objective tumor assessment and adverse events (AEs). Results: The median OS time was 17.58 months (95% CI: 15.18 – 23.03 months) in the experiment group and 13.17 months (95% CI: 11.14 – 18.76 months) in the control group (log-rank test, p = 0.021). There is no significantly difference in the median PFS between experiment group and control group (8.74 months, 95% CI: 6.41-14.85 months vs 10.38 months, 95% CI: 8.18-15.44 months, p = 0.695). No statistically significant difference was detected as regards to the objective tumor assessments. There is no significance in OS or PFS between MGMT positive and MGMT negative groups. TMZ treatment was well tolerated in the study. AE types and rates were generally similar between the two groups. There were 22 SAEs in this study, with only 1 SAE (lung infection) in Stupp regimen group was possibly drug-related. Conclusions: The addition of early post-surgery TMZ chemotherapy to the Stupp regimen for newly diagnosed GBM resulted in a statistically significant survival benefit with minimal additional toxicity. Clinical trial information: NCT00686725.

Thymic stromal lymphopoietin: a promising therapeutic target for allergic diseases

Thymic stromal lymphopoietin (TSLP), an interleukin 7-like cytokine, can trigger dendritic cell (DC)-mediated T-helper type 2 (Th2) inflammatory responses. Recent evidence demonstrates that cytokines TSLP and OX40 (CD134)/OX40 ligand seem to be important players in the maintenance of Th2 memory pool in the pathogenesis of asthma. Accumulating data reveal that the pathogenic T cells involved in asthma are likely to be inflammatory Th2 cells. TSLP is involved in the development of asthma through crosstalk with nuclear factor NF-ĸB. Progression of skin fibrosis in atopic dermatitis occurs via TSLP/TSLP receptor. TSLP-mediated dermal inflammation aggravates experimental allergic asthma. Also, TSLP polymorphisms are associated with susceptibility to asthma, atopic dermatitis, and eczema herpeticum. These findings suggest a master switch of TSLP in the initiation of allergic and adaptive inflammation through innate pathways at the epithelial cell-DC interface. The TSLP pathway is therefore a promising target for immunotherapy of allergic diseases.

Polymorphisms in toll-like receptor 4 gene are associated with asthma severity but not susceptibility in a Chinese Han population

BACKGROUND AND OBJECTIVES

The toll-like receptor 4 (TLR4) gene links human innate immunity and adaptive immunity via bacterial endotoxin recognition, and plays a considerable role in the pathogenesis of asthma. The effects of the genetic variants of TLR4 on asthma are still largely unknown. This study aimed to evaluate the effects of TLR4 polymorphisms on asthma risk and asthma-related phenotypes in a Chinese Han population.

METHODS

We consecutively recruited 318 unrelated adult asthmatic patients and 352 healthy volunteers. Four tagging single nucleotide polymorphisms (SNPs) in the TLR4 gene were detected using GenomeLab SNPstream or TaqMans Genotyping. We conducted case-control and case-only studies to investigate the association between the selected tagging SNPs in TLR4 and asthma and asthma-related phenotypes.

RESULTS

We found no evidence to support a significant association between TLR4 SNPs and asthma susceptibility. However, our results revealed that the TT homozygote of rs1927914 was associated with lower forced expiratory volume in the first second (percent predicted) in asthmatic patients. An evidently positive association was found between asthma severity and both the TT genotype of rs1927914 and the GG genotype of rs10983755 and rs1927907 (P = .024, P = .009, and P = .013, respectively), indicating that the C allele of rs1927914 and the A allele of rs10983755 and rs1927907 have a protective effect on asthma severity.

CONCLUSION

TLR4 polymorphisms do not contribute to asthma susceptibility but they may influence the severity of asthma.

Polymorphisms in the toll-like receptor 2 subfamily and risk of asthma: a case-control analysis in a Chinese population

BACKGROUND AND OBJECTIVE

Cell activation through toll-like receptors (TLRs) has robust bipolar effects on host immunity and the pathogenesis of asthma. The TLR2 subfamily is a pivotal member of the TLR family. We sought to determine whether mutations in TLR2 subfamily genes affect the risk of asthma.

METHODS

A total of 318 asthmatic patients and 352 nonasthmatic controls were recruited. Eight single-nucleotide polymorphisms in TLR2 subfamily genes were detected using GenomeLab SNPstream (Beckman Coulter, Fullerton, California, USA).

RESULTS

We found that patients with the TLR2/rs7656411 TT variant homozygote had a significantly reduced risk of asthma when compared with those with the GG wild-type homozygote (adjusted odds ratio [OR], 0.63; 95% confidence interval (CI], 0.41-0.98; P = .036). Furthermore, a positive association was observed between the T allele of rs2381289 in TLR6 and allergic rhinitis in asthma (OR, 1.79; 95% CI, 1.10-2.91; P = .025), while the A allele of rs11466651 in TLRIO was negatively associated with allergic rhinitis (OR, 0.49; 95% CI, 0.26-0.95; P = .046).

CONCLUSION

Our results indicate that a genetic variant in the TLR2 subfamily may play a role in susceptibility to asthma.

Computed tomography-guided aspiration versus key-hole craniotomy for spontaneous putaminal haemorrhage: a prospective comparison of minimally invasive procedures

OBJECTIVES

To compare the effectiveness of two minimally invasive procedures, namely computed tomography-guided aspiration and the key-hole approach, in the neurosurgical management for spontaneous putaminal haemorrhage, and to explore the indications for the two approaches.

DESIGN

A multicentre, single-blinded controlled trial.

SETTING

Hospitals taking part in this trial and the sources for patients were from China. Among others, the hospitals involved in the interventions included: the Beijing Tiantan Hospital (of the Capital University of Medical Sciences), the General Hospital of People's Liberation Army, the Peking Union Hospital, and the Shanghai Huashan Hospital (of the Fudan University medical school).

PATIENTS

From September 2001 to November 2003, data were available for analysis from a total of 841 patients with spontaneous putaminal haemorrhage from 135 hospitals all over China (except Tibet, Hong Kong, Taiwan, and Macao). All follow-up data were for at least 3 months.

MAIN OUTCOME MEASURES

Mortality, Glasgow Coma Scale score, postoperative complications, Kanofsky Performance Scale score, and Barthel Index.

RESULTS

There were 563 patients who underwent computed tomography-guided aspiration, and 165 were treated by the key-hole approach. Respective mortality rates 1 month after the operation were 17.9% and 18.3%; at 3 months they were 19.4% and 19.4%. In those undergoing computed tomography-guided aspiration, mortality rates at 3 months after the operation were 28.2% in patients with Glasgow Coma Scale scores of 8 or below, as opposed to 8.2% in those with higher scores. This amounted to a 3.4-fold difference. In those treated by the key-hole approach, the corresponding rates were 30.2% and 7.6%, which amounted to a 4-fold difference. The corresponding mortality at 3 months in patients with complications was 3.9 times as great as in those without complications. In those with haematoma volumes of 70 mL or greater, it was 2.7 times as much as in those in whom the volumes below 30 mL. The postoperative complication rate of computed tomography-guided aspiration (23.7%) did not differ significantly from that in those having the key-hole approach (25.7%) [P=0.420].

CONCLUSIONS

Computed tomography-guided aspiration is not superior to the key-hole approach for treating spontaneous putaminal haemorrhage in terms of favourable outcomes, mortality, and morbidity. However, it could be the first-choice approach for those with bleeds of 50 mL or less, while the key-hole approach may be more suitable for those with larger haematomas.

The optimal time-window for surgical treatment of spontaneous intracerebral hemorrhage: result of prospective randomized controlled trial of 500 cases

The aim of this clinical study was to determine the optimal time-window for surgical treatment of spontaneous intracerebral hemorrhage (ICH). From January 1998 to September 2000, 17 hospitals in Shanghai participated in a prospective randomized controlled trial. Among a consecutive series of 500 patients with spontaneous ICH, 234 underwent medical treatment and 266 patients received surgical treatment. According to the interval from initial onset to treatment, they were divided into 3 stages: ultra-early (< or =7 h), early (7-24 h), and delayed (> 24 h). Perioperative evaluation (Glasgow Outcome Score), long-term outcome (the activities of daily living [ADL] score), mortality, as well as incidence of associated complications were compared respectively. We found that: a) in the ultra-early and early stages, both the perioperative and long-term outcome of surgical treatment was definitely better than medical treatment; b) for the outcome of surgical treatment, there was no significant difference between ultra-early and early stages; c) in ultra-early stage, risk of postoperative rebleeding was significantly higher, and decreased henceforth; d) in delayed stage, incidence of associated respiratory, urinary, and gastrointestinal system complications was higher in surgery group than in medication group. In summary, our study yielded conclusive evidence that the early stage (within 7-24 h) was the optimal time-window for surgical intervention of spontaneous ICH.

Reduction of neural and vascular damage by transplantation of VEGF-secreting neural stem cells after cerebral ischemia

We determined the role of VEGF-transfected neural stem cells (NSCs) transplantation in rat brain subjected to ischemia. Fetal NSCs were cultured from E14 days SD rats and transfected with VEGF121 gene by using lipofectamine technique. Temporary middle cerebral artery occlusion (tMCAO) models were established and randomly divided into 1: control group, 2: PBS transplantation group, 3: NSCs transplantation group and 4: VEGF-secreting NSCs transplantation group. Grafts were transplanted into the penumbra zones 3 days after tMCAO model established. Neurological Severity Score (NSS) was checked in all groups 2-12 weeks after transplantation. By using immunofluorescent staining, VEGF expression of transplanted cells, differentiation and migration of transplanted NSCs after transplantation were detected. VEGF gene-transfected neural stem cells expressed gene products during the first 2 weeks. NSS in this group was significantly lower compared with that in other 3 groups 12 weeks after transplantation. VEGF gene-transfected NSCs migrated and expressed VEGF in hosts' brains, some of them differentiated to neurons 12 weeks after transplantation. VEGF-transfected NSCs expressed gene products during the early time after transplantation, which reduce brain injury through protecting the vascular system against ischemic attack.

Attenuation of temporary focal cerebral ischemic injury in the mouse following transfection with interleukin-1 receptor antagonist

The proinflammatory cytokine interleukin-1 beta (IL-1beta) is thought to play an important role in the stimulation of the inflammatory response following ischemia and reperfusion. This study investigated the inflammatory effect of IL-1beta during transient focal cerebral ischemia and reperfusion in the mouse transduced with the interleukin-1 receptor antagonist (IL-1ra) gene. An adenoviral vector encoding, either the human IL-1ra gene (AdRSVIL-1ra) or the LacZ gene (AdRSVlacZ) or normal saline, were injected into the right lateral ventricles of adult CD-1 mice (n=96). Five days later, the mice received 1 h temporary middle cerebral artery occlusion (tMACAO) followed by 23 h reperfusion. Cerebral blood flow (CBF), infarct volume, blood-brain barrier (BBB) permeability, and the number of intracellular adhesion molecule-1 positive vessels were measured to determine the effect of IL-1beta during postischemic reperfusion. Infarct volume in the AdRSVIL-1ra-transduced mice was markedly reduced compared to the AdRSVlacZ-transduced and saline-injected mice (36.0+/-5.3 mm(3) vs. 60.0+/-6.2 mm(3), 69. 5+/-6.3 mm(3), after 23 h of reperfusion, n=6-8 per group, p<0.05). BBB disruption and intracellular adhesion molecule-1 expression (135+/-23 vs. 311+/-40 and 357+/-51, n=6-8 per group, p<0.05) in the AdRSVIL-1ra-transduced mice were also less than that of the AdRSVlacZ-transduced and saline-injected mice. Our studies demonstrated that overexpression of IL-1ra in the mouse brain can downregulate intracellular adhesion molecule-1 expression both in the cortex and basal ganglia, which suggests that IL-1beta may play an important role in the activation of the inflammatory response during focal cerebral ischemia by promoting leukocyte adhesion to endothelial cells. The decrease of BBB disruption in AdRSVIL-1ra-transduced mice suggests that the endothelial cells may be a target for IL-1beta during postischemic reperfusion.

Expression of intercellular adhesion molecule 1 (ICAM-1) is reduced in permanent focal cerebral ischemic mouse brain using an adenoviral vector to induce overexpression of interleukin-1 receptor antagonist

Our previous studies have demonstrated that overexpression of recombinant human interleukin-1 receptor antagonist protein (IL-1ra) via gene transfer can reduce ischemic brain injury. However, the mechanism of action of IL-1ra in ischemia is unclear. Since interleukin-1 can up-regulate intercellular adhesion molecules in endothelium, the present study was designed to determine whether overexpression of the IL-1ra can reduce the expression of intercellular adhesion molecule-1 (ICAM-1) after ischemic injury. Normal saline or adenovirus vector (1x109 particles) encoding the human IL-1ra gene (Ad.RSVIL-1ra) or the Escherichia coli LacZ gene (Ad.RSVlacZ) was injected into the right lateral cerebral ventricle of adult CD-1 mice. After five days, permanent middle cerebral artery occlusion (MCAO) was achieved for 24 h using an intraluminal suture. Cerebral blood flow was monitored by transcranial laser Doppler flowmetry to verify the occlusion. ICAM-1 protein was quantified using Western blot analysis and localized using immunohistochemistry. After MCAO, surface blood flow in the ischemic hemisphere was decreased to 9-11% of the baseline. There were fewer ICAM-1 positive vessels in the ischemic cortex of the Ad.RSVIL-1ra transfected mice than in the Ad.RSVlacZ transfected and saline treated mice (138+/-19 vs. 249+/-25, 284+/-22, p<0.05). Western blot analysis shows that ICAM-1 protein decreased 50-60% in the Ad. RSVIL-1ra group compared to the other two groups. There were no significant differences in the numbers of positive vessels in the ischemic basal ganglia and contralateral hemisphere among the three groups. Our studies suggest that IL-1ra overexpression can down-regulate the expression of ICAM-1 in the ipsilateral cortex in ischemic mice. Interleukin-1 may play an important role in the activation of inflammatory reaction during focal cerebral ischemia by promoting leukocyte adhesion on the endothelium cells.

Focal cerebral ischemia in the mouse: description of a model and effects of permanent and temporary occlusion

Our study is to demonstrate the advantages and disadvantages of middle cerebral artery occlusion (MCAO) model in the mouse. CD-1 mice had permanent MCAO for 24 h, or temporary occlusion for either 1 h followed by 23 h of reperfusion or 2 h of occlusion with 22 h of reperfusion. The infarct volume and blood-brain barrier disruption were smaller in the 1-h/23-h temporary occlusion than in either the 24-h permanent occlusion group or the 2-h/22-h temporary occlusion group (p<0.05). Our study demonstrates that blood flow, infarct volume, and blood-brain barrier disruption remain important markers of focal cerebral ischemia.

Gamma knife radiosurgery for hemangioblastomas

Thirteen patients (11 males, 2 females) with cerebral hemangioblastomas (HABs) were treated with Gamma Knife radiosurgery (GKR). Four patients had multiple lesions in the brain. The remainder had a single lesion. The total number of lesions was 20. Eight cases had recurrent or residual HABs after surgery. In one case diagnosis was confirmed following surgical resection 22 months after GKR. One case was diagnosed by computed tomography (CT), magnetic resonance imaging (MRI) and digital subtraction angiography (DSA). Three patients had von Hippel Lindau (VHL) disease. The mean tumor diameter was 20 mm (range 7.5 to .55 mm). The mean margin dose was 18 Gy (range 12 to 24 Gy). In 5 cases, there was an improvement of symptoms and reduction in tumor volume. In 4 cases the tumor volume and clinical status remained unchanged. In 3 patients, there was clinical deterioration. The cause of this was an increase in tumor cyst volume in 2 cases. Subsequent surgery resulted in clinical improvement. In a third patient with multiple lesions, deterioration was the result of adverse radiation effects in the medulla oblongata. Three patients were subjected to post GKR-surgery with subsequent histopathology. In one, this was due to cyst expansion. In one, it was at the patient's insistence in the presence of a stable clinical and radiological picture. In a third patient with a temporal lobe tumor, it was because of late-developing epileptic seizures. The histopathological findings in these patients showed varying degrees of small vessel thickening and occlusion together with loss of tumor cells. The observations varied in degree according to the time between GKR and the secondary operation. These findings indicate the effectiveness of the treatment. The reduction in vascularity suggests that GKR could make subsequent surgery less hazardous. The observations of this study suggest that while GKR is not adequately reliable for the control of HAB cysts, it can be an effective treatment for solid tumors, especially those in eloquent regions.

Effects of mild hypothermia on the release of regional glutamate and glycine during extended transient focal cerebral ischemia in rats

The present study is to determine the effect of mild hypothermia (MHT) on the release of glutamate and glycine in rats subjected to middle cerebral artery occlusion and reperfusion. The relationship between amino acid efflux and brain infarct volume was compared in different periods during MHT. Reversible middle cerebral artery occlusion was performed in Sprague-Dawley rats using a suture model. The rats were divided into four groups including (1) MHT during ischemia (MHTi), (2) MHT during reperfusion (MHTr), (3) MHT during ischemia and reperfusion (MHTi + r), and (4) a normothermic group (NT). Extracellular concentrations of glutamate and glycine in the cortex and striatum were monitored using in vivo microdialysis and analyzed using high-performance liquid chromatography. Morphometric measurements for infarct volume were performed using 2,3,5-triphenyltetrazolium chloride staining. The increase of glutamate and glycine in the ischemic cortex of the MHTi and MHTi + r rats during ischemic and reperfusion periods was significantly less than that of the NT rats (p < 0.05). However, there was no statistical difference among these groups in the peak of glutamate and glycine release in the striatum. Infarct volume paralleled the release of glutamate and glycine. The protective effect of MHTi and MHTi + r in reducing ischemia and reperfusion brain injury may be due to the attenuation of both glutamate and glycine release during ischemia and reperfusion.

The effect of extending mild hypothermia on focal cerebral ischemia and reperfusion in the rat

The aim of the present study is to compare the influence of timing and duration of mild hypothermia on rats subjected to 3 h of middle cerebral artery occlusion followed by 72 h of reperfusion. Sixty-four Sprague-Dawley rats were divided into three mild hypothermic groups according to the duration of mild hypothermia (MHT 32 +/- 0.2 degrees C): intra-ischemia (MHTi); intra-reperfusion (MHTr); and intra-ischemia/ reperfusion (MHTi + r). Our control group was normothermic (NT 37 +/- 0.2 degrees C). Reversible focal cerebral ischemia was carried out in rats with a suture technique. Cerebral blood flow was measured by laser Doppler flowmetry to confirm occlusion and reperfusion. The permeability of the blood-brain barrier was determined by the extravasation of Evans's blue dye, and infarct volumes were measured by 2,3,5-triphenyltetrazolium chloride staining at 72 h after reperfusion. Acute post-ischemic hyperperfusion and delayed hypoperfusion in the ischemic perifocal area and sustained hypoperfusion in the ischemic core were inhibited in MHTi + r and MHTi rats (p < 0.05) as compared to the NT rats. The action of MHTi + r on preventing post-ischemic progressive hypoperfusion in the perifocal area was more effective than that of MHTi 2 h after reperfusion (p < 0.05). Blood-brain barrier disruption in the basal ganglia and cortex areas was significantly reduced in both MHTi + r and MHTi groups, and especially the former. Infarct volume was significantly reduced in both MHTi and MHTi + r groups (p < 0.05). MHTi and MHTi + r have protective effects for reducing ischemia/reperfusion injury. The potential mechanisms may include inhibition of post-ischemic hyperperfusion, and delayed and sustained hypoperfusion.

Stereotactic Gamma thalamotomy for the treatment of parkinsonism

From September 1994 to June 1995, eight patients with intractable parkinsonism underwent gamma thalamotomy in our hospital. All of these patients were male, with an average age of 59.3 years. The duration of the disease from initial diagnosis was 2-10 years (mean 6.8 years). All had failed or had serious side effects with antiparkinsonian medicine. Seven cases had tremor-dominant symptoms, while the other had mainly rigidity. Six cases had bilateral symptoms. Computed tomography or magnetic resonance imaging (MRI) was undertaken prior to treatment in all cases to exclude focal brain lesions. Stereotactic MRI was taken with the Leksell frame in place and both T1- and T2-weighted images were obtained. The targets were located in the area of Vim/Voa/Vop based on the Schaltenbrand atlas. In seven cases, two plugged 4-mm-collimator shots were used. The maximum dose was 160 Gy in six cases and 180 Gy in one case. In another case, a single 4-mm-collimator shot was used, and a maximum dose of 160 Gy was delivered to the target center. The border of the internal capsule was outside the 20-30% isodose line. We intended the 50% isodose line to have an oval-shaped region with the use of two shots and should correspond to the shape of Vim. Follow-up data were available for six patients (mean: 4.5 months, range: 2-9 months). Tremor disappeared in three cases and improved in the other three. In one of these six cases, the tremor disappeared just 3 days after gamma thalamotomy. Rigidity improved in four of these six cases. In only one patient, treated with a maximum dose of 180 Gy, was there any contralateral limb weakness, which developed 3 months after treatment and has been recovering gradually. Follow-up MRI T2-weighted images in this case showed that the diameter of the lesion was larger than intended and there was a region of diffuse edema in the thalamus and upper brain stem. No other complications occurred in this series.

[Further experience in the diagnosis and treatment of sphenoidal ridge meningioma]

72 cases with sphenoidal ridge meningioma operated on in recent 12 years in our department were reported. In the microsurgical group and non-microsurgical group, the rate of total removal of medial tumors was 65% and 20% respectively (P < 0.01); lateral tumors was 100% and 77% respectively (P > 0.05); the mortality was 6.7% and 11.9% respectively (P > 0.05); the rate of neurological impaired was 33.3% and 64.3% respectively (P < 0.001); good rate of following up for a long time was 87.5% and 16.7% in medial group respectively (P < 0.05); 66.7% and 75% in lateral group respectively (P > 0.05). It is believed that application of CT and angiography and microsurgical technique is helpful to the diagnosis and treatment of sphenoidal ridge meningioma.

Cerebral artery reconstruction in the treatment of large and giant intracranial aneurysms

From 1978 to 1988, 14 giant intracranial aneurysms (more than 2.4 cm in diameter) and one large aneurysm (1.5 cm in diameter) were treated by extracranial/intracranial (EC/IC) bypass or cerebral artery reconstruction. Of the aneurysms, 10 were located at the intracavernous carotid artery (CCA). One of the 10 aneurysms was posttraumatic and located at both the carotid-ophthalmic artery segment and the bifurcation of the internal carotid artery (ICA). Three were seen at the middle cerebral artery (MCA) trunk. The aneurysms were demonstrated by angiography and CT scanning. They were treated with trapping of the aneurysm and superficial temporal artery (STA)/middle cerebral artery (STA-MCA) bypass with/without a graft (6 cases), cervical ICA ligation and STA-MCA bypass with/without a graft (6) aneurysm excision with an end-to-end anastomosis of the MCA and a STA-MCA bypass with a graft (1), proximal MCA occlusion and STA-MCA bypass with a graft (1), and aneurysm neck clipping following a STA-MCA bypass with a graft (1). The patients showed marked improvement after operation except one whose neurological deficit was aggravated temporarily. Postoperative angiography revealed that the anastomoses were patent in all cases. No surgical mortality or any delayed ischemic complications were noted after follow-up for 5.6 years. We believe that cerebral artery reconstruction or EC/IC bypass is still effective in the treatment of large and giant intracranial aneurysms.

Temporary arterial occlusion during intracranial aneurysm surgery

Temporary arterial occlusion during intracranial aneurysm surgery is a safe and effective modality. It is not only an emergency measure for controlling aneurysmal bleeding, but also a helpful means for accurate and meticulous dissection and clipping of an intracranial aneurysm with the advantage of minimizing the chance of its premature rupture or causing damage to the vital neurovascular structures. This technique is especially useful for treating large or giant aneurysms, carotid-ophthalmic arterial aneurysms, or thin-walled and complicated aneurysms tightly adherent to their surrounding tissues. A series of 52 patients with temporary clipping of the involved arteries during intracranial aneurysm surgery were reviewed retrospectively, which represented 37.1% of all aneurysms operated on in Huashan Hospital, Shanghai Medical University during the same period (from 1980 to 1990). Of them, one died (1.9%), 10(19.2%) had immediate or early neurological deficits which were mostly resolved later. A follow-up study with an average time of 3.8 years showed that 98% of patients had an excellent and good recovery without significant deficits. Comparing these results with those in 88 patients with aneurysms operated on over the same period in which temporary clips were not used, there is clearly no significant difference. The use of brain protectors, barbiturates, hypothermia and some monitoring systems can increase the safe coefficient to the brain and reduce the occurrence of ischemic complications during the application of temporary arterial occlusion. However, there is so far neither an absolute reliable medication or monitor, nor a well accepted safe time-limits to vascular occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Research on hemodynamics of cerebral arteriovenous malformation by Doppler ultrasound

Combined extracranial and transcranial Doppler (TCD) instruments were used to study the hemodynamics of 20 patients with cerebral arteriovenous malformation (AVM) proved angiographically. It was discovered that the flow velocities in AVM-feeding arteries and their proximal arteries were increased; the increase of flow velocities in feeding arteries close to AVM was more remarkable than that in feeding-arteries proximal to extracranial internal carotid artery far from AVM; pulsating indexes of AVM-feeding arteries were decreased; increase of flow velocities in AVM-feeding arteries was related to the decrease of pulsating index; the flow velocities of nontapering feeding arteries were faster than those of tapering arteries; the greater the size of AVM, the faster the velocity in feeding artery; and the flow velocities and pulsating indexes of AVM-feeding arteries were gradually recovered to normal 3-5 weeks after resection of AVM. It is believed that increase of flow velocity in AVM-feeding artery is associated with distention and decreased resistance of flow in AVM-feeding artery. TCD combined with CT scans are helpful to the diagnosis of AVM. Combination of TCD and cerebral angiography (CAG) to evaluate comprehensively the preoperative hemodynamics of AVM and to monitor postoperative changes is helpful to detecting cerebral steal due to steal leakage in circle of Willis and preventing the hazardous postoperative complications caused by pressure breakthrough of normal perfusion.

[Effect of dihydroepiandrosterone sulfate on the tension of uterine cervix and its mechanisms]

After i.v. injection of dihydroepiandrosterone sulfate (DHA-S) at 20 or 40 mg/kg to female rats on day 19 of gestation, the tension and hydroxyproline level of uterine cervix were decreased obviously. However, DHA-S at 10 mg/kg showed no effect on the tension of uterine cervix. DHA-S in vitro, at 0.1 mg/kg significantly increased estradiol secretion in the ovaries and placenta of late pregnant rats.

[Application of temporary arterial occlusion during intracranial aneurysm surgery]

Temporary arterial occlusion during aneurysm surgery was performed in 52 patients. It account for 37.1% of all aneurysm operated in the same period. After operation 1 patient died (1.9%), 10 (19.2%) remained neurological deficits but 48 (98%) got excellent and good recovery. Selection of patients and supplement therapeutic measures were discussed in the article.

Intracranial epidermoid tumours: thirty-seven years of diagnosis and treatment

The clinical, operative and pathological characteristics of 102 consecutive cases of intracranial epidermoid tumours are reported. These cases constituted 1.1% of all intracranial tumours and 13.5% of congenital neoplasma admitted to our service in the period 1951-88. Of 91 (89.2%) intradural tumours, 74 (72.5%) were in the subarachnoid cisterns, especially in the cerebellopontine angle cistern (31 cases). The tumours were solid in 69 cases (67.6%) and cystic in 26 (25.5%); the remaining 7 cases were not recorded. There were no specific clinical features with which to identify the nature and extent of the tumour. Diagnosis and treatment are described, with an evaluation of CT and MRI. Before 1981, total removal rate of tumour was 29.3%; after that date it was 72.7% with the aid of microsurgery. The overall surgical mortality rate was 4.9% (5 cases), but there were no deaths in the microsurgical group. Follow-up for a period of 0.5-37 years (mean 13 years) was carried out in 68 patients (70.1%). Among 24 patients with incomplete removal, recurrence of tumour was verified in 4 cases; 3 underwent reoperation with excellent or good results. One patient refused operation and died. All the remaining 20 cases, save 3 who died of other diseases, returned to their normal activities without recurrent manifestations. The results suggest that the primary treatment of epidermoid tumours should be surgical removal including the contents and capsule of a tumour. With the aid of microsurgical technique, complete removal is possible. Patients with incomplete removal can also obtain a long-term favourable result.

Effect of (-)- and (+)-gossypol on fertility in male rats

(+)-Gossypol has neither antifertility effect nor toxicity at the dosage of 30 mg/kg orally for 14 days in male rats, but slight damage was found in the germinal epithelium of the testis in animals dosed for 4 weeks. (-)-Gossypol at 30 mg/kg orally for 7 days clearly had an antifertility effect in male rats. It appears that (-)-gossypol is the active stereoisomer of racemic gossypol.