Na+/Ca2+ Exchanger 3 is Downregulated in the Hippocampus and Cerebrocortex of Rats with Hyperthermia-induced Convulsion

Background:

Na⁺/Ca²⁺ exchanger (NCX) plays a crucial role in pentylenetetrazol-induced convulsion. However, it is unclear whether NCX is critically involved in hyperthermia-induced convulsion. In this study, we examined the potential changes in NCX3 in the hippocampus and cerebrocortex of rats with hyperthermia-induced convulsion.

Methods:

Twenty-one Sprague Dawley rats were randomly assigned to control group, convulsion-prone group and convulsion-resistant group (n = 7 in each group). Whole-cell patch-clamp method was used to record NCX currents. Both the Western blotting analysis and immunofluorescence labeling techniques were used to examine the expression of NCX3.

Results:

NCX currents were decreased in rats after febrile convulsion. Compared to the control group, NCX3 expression was decreased by about 40% and 50% in the hippocampus and cerebrocortex of convulsion-prone rats, respectively. Furthermore, the extent of reduction in NCX3 expression seemed to correlate with the number of seizures.

Conclusions:

There is a significant reduction in NCX3 expression in rats with febrile convulsions. Our findings also indicate a potential link between NCX3 expression, febrile convulsion in early childhood, and adult onset of epilepsy.     

Retarded hippocampal development following prenatal exposure to ethanolic leaves extract of Datura metel in wistar rats

Background:

Datura metel contains atropine alkaloids and has been used to treat complication like asthma and, bronchitis, because of its anticholinergic properties.

Aim:

This study aimed to determine the prenatal effects of ethanolic extract of D. metel leaves exposure on the development of hippocampus.

Materials and Methods:

Twenty rats (12 females and 8 males) were purchased. The females were grouped into four groups (A_D). Group A were given 500 mg/kg body weight of the extract on the first day of fertilization to the end of gestation period, Group B were given 500 mg/kg body weight on the 8^th day of fertilization to the end of gestation period, Group C were given 500 mg/kg body weight on 15^th day of fertilization to the end of gestation period and Group D were given normal saline throughout the gestation period.

Results:

Rats in Group A showed no implantation, rats in Group B had abortion on the 7^th day after administration, and rats in Group C gave birth with their litters showing retarded hippocampus development and neural degeneration and rats in Group D (control) showed normal development.

Conclusion:

Ethanolic extract of D. metel leaf is teratogenic in the late stage of pregnancy, is abortificient and can serve as a contraceptive.     

Hyperbaric Oxygen and Ginkgo Biloba Extract Ameliorate Cognitive and Memory Impairment via Nuclear Factor Kappa-B Pathway in Rat Model of Alzheimer's Disease

Background:

Hyperbaric oxygen (HBO) and Ginkgo biloba extract (e.g., EGB 761) were shown to ameliorate cognitive and memory impairment in Alzheimer''s disease (AD). However, the exact mechanism remains elusive. The aim of the present study was to investigate the possible mechanisms of HBO and EGB 761 via the function of nuclear factor kappa-B (NF-κB) pathway.

Methods:

AD rats were induced by injecting β-amyloid 25–35 into the hippocampus. All animals were divided into six groups: Normal, sham, AD model, HBO (2 atmosphere absolute; 60 min/d), EGB 761 (20 mg·kg⁻¹·d⁻¹), and HBO/EGB 761 groups. Morris water maze tests were used to assess cognitive, and memory capacities of rats; TdT-mediated dUTP Nick-End Labeling staining and Western blotting were used to analyze apoptosis and NF-κB pathway-related proteins in hippocampus tissues.

Results:

Morris water maze tests revealed that EGB 761 and HBO significantly improved the cognitive and memory ability of AD rats. In addition, the protective effect of combinational therapy (HBO/EGB 761) was superior to either HBO or EGB 761 alone. In line, reduced apoptosis with NF-κB pathway activation was observed in hippocampus neurons treated by HBO and EGB 761.

Conclusions:

Our results suggested that HBO and EGB 761 improve cognitive and memory capacity in a rat model of AD. The protective effects are associated with the reduced apoptosis with NF-κB pathway activation in hippocampus neurons.     

Long-term spatial memory and morphological changes in hippocampus of Wistar rats exposed to smoke from Carica papaya leaves

Objective

To investigate the effects of smoking of dried leaves of Carica papaya (pawpaw) based on ethnopharmacological information which indicated that smoking of papaya leaves could influence motor performance and learning.

Methods

Twenty-four rats were used for the study, and were grouped into four groups. Groups 1 served as the control (not exposed to papaya leaves smoke), while Groups 2, 3 and 4 were exposed to smoke from 6.25 g, 12.50 g and 18.75 g of dry pawpaw leaves respectively in a smoking chamber twice daily for 21 d with each exposure lasting for 3 min. Lastly, hippocampus was harvested in each group for histological study.

Results

The results showed that there were significant (P<0.05) increases in mean of recall latencies of long-term spatial memory in the animal administered the high dose while the other groups had significantly (P<0.05) lower frequencies. Histological investigation showed signs of mild neural degeneration in high dose group and hypochromic appearance of the Nissl substance in all treated groups.

Conclusions

In conclusion, the findings from this study has demonstrated that smoking of papaya leaves has the ability to maintain an intact long-term spatial memory at all doses but retrieving such memory is faster with the low and medium dosages.     

Activation of γ-aminobutyric Acid (A) Receptor Protects Hippocampus from Intense Exercise-induced Synapses Damage and Apoptosis in Rats

Background:

Our previous study has confirmed that one bout of exhaustion (Ex) can cause hippocampus neurocyte damage, excessive apoptosis, and dysfunction. Its initial reason is intracellular calcium overload in hippocampus triggered by N-methyl-D-aspartic acid receptor (NMDAR) over-activation. NMDAR activation can be suppressed by γ-aminobutyric acid (A) receptor (GABA_AR). Whether GABA_AR can prevent intense exercise-induced hippocampus apoptosis, damage, or dysfunction will be studied in this study.

Methods:

According to dose test, rats were randomly divided into control (Con), Ex, muscimol (MUS, 0.1 mg/kg) and bicuculline (BIC, 0.5 mg/kg) groups, then all rats underwent once swimming Ex except ones in Con group only underwent training. Intracellular free calcium concentration ([Ca²⁺]i) was measured by Fura-2-acetoxymethyl ester; glial fibrillary acidic protein (GFAP) and synaptophysin (SYP) immunofluorescence were also performed; apoptosis were displayed by dUTP nick end labeling (TUNEL) stain; endoplasmic reticulum stress-induced apoptosis pathway was detected by Western blotting analysis; Morris water maze was used to detect learning ability and spatial memory.

Results:

The appropriate dose was 0.1 mg/kg for MUS and 0.5 mg/kg for BIC. Ex group showed significantly increased [Ca²⁺]i and astrogliosis; TUNEL positive cells and levels of GFAP, B cell lymphoma-2 (Bcl-2) associated X protein (Bax), caspase-3, caspase-12 cleavage, CCAAT/enhancer binding protein homologous protein (CHOP), and p-Jun amino-terminal kinase (p-JNK) in Ex group also raised significantly compared to Con group, while SYP, synapse plasticity, and Bcl-2 levels in Ex group were significantly lower than those in Con group. These indexes were back to normal in MUS group. BIC group had the highest levels of [Ca²⁺]i, astrogliosis, TUNEL positive cell, GFAP, Bax, caspase-3, caspase-12 cleavage, CHOP, and p-JNK, it also gained the lowest SYP, synapse plasticity, and Bcl-2 levels among all groups. Water maze test showed that Ex group had longer escape latency (EL) and less quadrant dwell time than Con group; all indexes between MUS and Con groups had no significant differences; BIC had the longest EL and least quadrant dwell time among all groups.

Conclusions:

Activation of GABA_A R could prevent intense exercise-induced synapses damage, excessive apoptosis, and dysfunction of hippocampus.     

Effect of Pulsed Radiofrequency on Rat Sciatic Nerve Chronic Constriction Injury: A Preliminary Study

Background:

Pulsed radiofrequency (PRF) application to the dorsal root ganglia can reduce neuropathic pain (NP) in animal models, but the effect of PRF on damaged peripheral nerves has not been examined. We investigated the effect of PRF to the rat sciatic nerve (SN) on pain-related behavior and SN ultrastructure following chronic constriction injury (CCI).

Methods:

The analgesic effect was measured by hindpaw mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL). Twenty rats with NP induced by ligating the common SN were then randomly divided into a PRF treatment group and a sham group. The contralateral SN served as a control. The MWT and TWL were determined again 2, 4, 6, 8, 10, 12, and 14 days after the PRF or sham treatment. On day 14, ipsilateral and contralateral common SNs were excised and examined by electron microscopy.

Results:

Ipsilateral MWT was significantly reduced and TWL significantly shorter compared to the contralateral side 14 days after CCI (both P = 0.000). In the PRF group, MWT was significantly higher and TWL significantly longer 14 days after the PRF treatment compared to before PRF treatment (both P = 0.000), while no such difference was observed in the sham group (P > 0.05). Electron microscopy revealed extensive demyelination and collagen fiber formation in the ipsilateral SN of sham-treated rats but sparse demyelination and some nerve fiber regrowth in the PRF treatment group.

Conclusions:

Hyperalgesia is relieved, and ultrastructural damage ameliorated after direct PRF treatment to the SN in the CCI rat model of NP.     

Underlying Mechanisms of Memory Deficits Induced by Etomidate Anesthesia in Aged Rat Model: Critical Role of Immediate Early Genes

Background:

Etomidate (R-1-[1-ethylphenyl] imidazole-5-ethyl ester) is a widely used anesthetic drug that had been reported to contribute to cognitive deficits after general surgery. However, its underlying mechanisms have not been fully elucidated. In this study, we aimed to explore the neurobiological mechanisms of cognitive impairments that caused by etomidate.

Methods:

A total of 30 Sprague-Dawley rats were used and divided into two groups randomly to receive a single injection of etomidate or vehicle. Then, the rats’ spatial memory ability and neuronal survival were evaluated using the Morris water maze test and Nissl staining, respectively. Furthermore, we analyzed levels of oxidative stress, as well as cyclic adenosine 3’,5’-monophosphate response element-binding (CREB) protein phosphorylation and immediate early gene (IEG, including Arc, c-fos, and Egr1) expression levels using Western blot analysis.

Results:

Compared with vehicle-treated rats, the etomidate-treated rats displayed impaired spatial learning (day 4: 27.26 ± 5.33 s vs. 35.52 ± 3.88 s, t = 2.988, P = 0.0068; day 5: 15.84 ± 4.02 s vs. 30.67 ± 4.23 s, t = 3.013, P = 0.0057; day 6: 9.47 ± 2.35 s vs. 25.66 ± 4.16 s, t = 3.567, P = 0.0036) and memory ability (crossing times: 4.40 ± 1.18 vs. 2.06 ± 0.80, t = 2.896, P = 0.0072; duration: 34.00 ± 4.24 s vs. 18.07 ± 4.79 s, t = 3.023, P = 0.0053; total swimming distance: 40.73 ± 3.45 cm vs. 27.40 ± 6.56 cm, t = 2.798, P = 0.0086) but no neuronal death. Furthermore, etomidate did not cause oxidative stress or deficits in CREB phosphorylation. The levels of multiple IEGs (Arc: vehicle treated rats 100%, etomidate treated rats 86%, t = 2.876, P = 0.0086; c-fos: Vehicle treated rats 100%, etomidate treated rats 72%, t = 2.996, P = 0.0076; Egr1: Vehicle treated rats 100%, etomidate treated rats 58%, t = 3.011, P = 0.0057) were significantly reduced in hippocampi of etomidate-treated rats.

Conclusion:

Our data suggested that etomidate might induce memory impairment in rats via inhibition of IEG expression.     

Behavioral Effects of Deep Brain Stimulation of the Anterior Nucleus of Thalamus,Entorhinal Cortex and Fornix in a Rat Model of Alzheimer's Disease

Background:

Recent clinical and preclinical studies have suggested that deep brain stimulation (DBS) can be used as a tool to enhance cognitive functions. The aim of the present study was to investigate the impact of DBS at three separate targets in the Papez circuit, including the anterior nucleus of thalamus (ANT), the entorhinal cortex (EC), and the fornix (FX), on cognitive behaviors in an Alzheimer''s disease (AD) rat model.

Methods:

Forty-eight rats were subjected to an intrahippocampal injection of amyloid peptides 1-42 to induce an AD model. Rats were divided into six groups: DBS and sham DBS groups of ANT, EC, and FX. Spatial learning and memory were assessed by the Morris water maze (MWM). Recognition memory was investigated by the novel object recognition memory test (NORM). Locomotor and anxiety-related behaviors were detected by the open field test (OF). By using two-way analysis of variance (ANOVA), behavior differences between the six groups were analyzed.

Results:

In the MWM, the ANT, EC, and FX DBS groups performed differently in terms of the time spent in the platform zone (F_(2,23) = 6.04, P < 0.01), the frequency of platform crossing (F_(2,23) = 11.53, P < 0.001), and the percent time spent within the platform quadrant (F_(2,23) = 6.29, P < 0.01). In the NORM, the EC and FX DBS groups spent more time with the novel object, although the ANT DBS group did not (F_(2,23) = 10.03, P < 0.001). In the OF, all of the groups showed a similar total distance moved (F_(1,42) = 1.14, P = 0.29) and relative time spent in the center (F_(2,42) = 0.56, P = 0.58).

Conclusions:

Our results demonstrated that DBS of the EC and FX facilitated hippocampus-dependent spatial memory more prominently than ANT DBS. In addition, hippocampus-independent recognition memory was enhanced by EC and FX DBS. None of the targets showed side-effects of anxiety or locomotor behaviors.     

Protective Effects of Estradiol on Myocardial Contractile Function Following Hemorrhagic Shock and Resuscitation in Rats

Background:

Hemorrhagic shock (HS) results in myocardial contractile dysfunction. Studies showed that 17β-estradiol protects the myocardium against contractile dysfunction. The study investigated the cardioprotective effects of treatment with 17β-estradiol before resuscitation following 1 h of HS and resuscitation.

Methods:

Male Sprague-Dawley rats were assigned to 2 sets of experimental protocols: Ex vivo and in vivo treatment and resuscitation. Each set had three experimental groups (n = 6 per group): Normotensive (N), HS and resuscitation (HS-R) and HS rats treated with 17β-estradiol (E) and resuscitated (HS-E-R). Rats were hemorrhaged over 60-min to reach a mean arterial blood pressure of 40 mmHg. In the ex vivo group, hearts were resuscitated by perfusion in the Langendorff system. In the 17β-estradiol treated group, 17β-estradiol 280 µg/kg was added for the first 5 min. Cardiac function was measured. Left ventricular generated pressure (LVGP) and +dP/dt were calculated. In the in vivo group, rats were treated with 17β-estradiol 280 µg/kg s.c. after 60-min HS. Resuscitation was performed in vivo by the reinfusion of the shed blood for 30-min to restore normotension.

Results:

Treatment with 17β-estradiol before resuscitation in ex vivo treated and resuscitated isolated hearts and in the in vivo treated and resuscitated rats following HS improved myocardial contractile function. In the in vivo treated group, LVGP and +dP/dt max were significantly higher in 17β-estradiol treated rats compared to the untreated group (LVGP 136.40 ± 6.61 compared to 47.58 ± 17.55, and +dP/dt 661.85 ± 49.88 compared to 88.18 ± 0.85). Treatment with 17β-estradiol improved LVGP following HS.

Conclusions:

The results indicate that treatment with 17β-estradiol before resuscitation following HS protects the myocardium against dysfunction.     

The role of prophylactic antimalarial in the reduction of placental parasitemia among pregnant women in Calabar, Nigeria

Introduction:

Intermittent preventive treatment of malaria with sulfadoxine-pyrimethamine is a recommendation of the World Health Organization as part of the malaria control strategy in pregnancy in areas with malaria burden.

Aim:

This study set out to appraise the effectiveness of this regimen in the prevention of placental parasitemia among parturients in Calabar, Nigeria.

Materials and Methods:

Pretested, precoded questionnaires were administered to eligible women at the antenatal clinic and later updated at the labor ward. Intermittent preventive treatment was administered under direct observation at the clinic, while packed cell volume, placental parasitemia, and other laboratory tests were measured at the labor ward.

Results:

The gross presence of placental malaria in the intermittent preventive treatment (IPT)-treated and the control groups was 10.6% and 11.3% respectively (P=0.76). Anemia occurred in 3.1% of the IPT-treated group compared to 11.7% among the control group (P=0.000). Only 7.9% of the IPT-treated women had moderate to severe placental parsitemia whereas as many as 53.2% of women in the control group had moderate to severe parasitemia (P=0.000).

Conclusion:

Intermittent preventive treatment of malaria with sulfadoxine-pyrimethamine was associated with significant reduction in the degree of placental parasitemia among women in the IPT-treated group, although it did not completely eradicate placental malaria in the treatment group.     

Phloroglucinol Protects the Urinary Bladder Via Inhibition of Oxidative Stress and Inflammation in a Rat Model of Cyclophosphamide-induced Interstitial Cystitis

Background:

Phloroglucinol plays an important role in oxidative stress and inflammatory responses. The effects of phloroglucinol have been proven in various disease models. The aim of the present study was to investigate the efficacy and possible mechanisms of phloroglucinol in the treatment of interstitial cystitis (IC).

Methods:

Thirty-two female Sprague-Dawley (SD) rats were used in this study. IC was induced by intraperitoneal injection of cyclophosphamide (CYP). Rats were randomly allocated to one of four groups (n = 8 per group): A control group, which was injected with saline (75 mg/kg; i.p.) instead of CYP on days 1, 4, and 7; a chronic IC group, which was injected with CYP (75 mg/kg; i.p.) on days 1, 4, and 7; a high-dose (30 mg/kg) phloroglucinol-treated group; and a low-dose (15 mg/kg) phloroglucinol-treated group. On day 8, the rats in each group underwent cystometrography (CMG), and the bladders were examined for evidence of oxidative stress and inflammation. Statistical analysis was performed by analysis of variance (ANOVA) followed by least square difference multiple comparison post-hoc test.

Results:

Histological evaluation showed that bladder inflammation in CYP-treated rats was suppressed by phloroglucinol. CMG revealed that the CYP treatment induced overactive bladder in rats that was reversed by phloroglucinol. Up-regulated tumor necrosis factor-α and interleukin-6 expression in the CYP-treated rats were also suppressed in the phloroglucinol treated rats. CYP treatment significantly increased myeloperoxidase activity as well as the decreased activities of catalase of the bladder, which was reversed by treatment with phloroglucinol.

Conclusions:

The application of phloroglucinol suppressed oxidative stress, inflammation, and overactivity in the bladder. This may provide a new treatment strategy for IC.     

Aqueous seed extract of Cola nitida rubra reduces serum reproductive hormone concentrations and sperm count in adult male albino Wistar rats

Background:

Following the high rate of consumption of Cola nitida (cola nut) among the male population in Nigeria, this study seeks to determine the effects of consumption of Cola nitida on serum reproductive hormones and sperm count, which are major determinants of male fertility.

Materials and Methods:

Thirty-two male albino wistar rats weighing 180-220 g were used for this study and were divided into 4 groups of eight animals each. Group 1 served as control, group 2 received 2 mg/kg Cola nitida extract (Test 1), group 3 received 6 mg/kg Cola nitida extract (Test 2) and group 4 received 10 mg/kg Cola nitida extract (Test 3). After 6 weeks of treatment, reproductive hormonal assay was carried out using the rat serum. Epididymal spermatozoa were collected and sperm count determined.

Results:

Serum concentrations of luteinizing hormone (LH) and testosterone were significantly (P < 0.05) reduced in test 2 and 3, compared with control. Sperm count was significantly lower in test group 1 (P < 0.05), 2 (P < 0.001) and 3 (P < 0.001) compared with control, with test 3 significantly (P < 0.05) lower compared with test 1. There was no significant difference in testicular and epididymis weight in the different experimental groups studied.

Conclusion:

Aqueous seed extract of Cola nitida rubra resulted in reduced serum reproductive hormone concentrations and sperm count in male wistar rats, and may therefore be detrimental to reproductive health, hence the need for regulation of its consumption.     

Effects of Continuous Positive Airway Pressure on Cognitive Deficits in Middle-aged Patients with Obstructive Sleep Apnea Syndrome: A Meta-analysis of Randomized Controlled Trials

Background:

Current views on continuous positive airway pressure (CPAP) treatment to improve the cognitive deficits of patients with obstructive sleep apnea syndrome (OSAS) are controversial, so we performed a meta-analysis.

Methods:

A comprehensive literature search was undertaken in PubMed, CINAHL, Medline, PsycInfo, EMBASE, Cochrane Library, CNKI, WanFang, VIP, and CBMdisc for studies published from June 1971 to July 2014. The outcome measures included neuropsychological tests of the 7 cognitive domains detailed below.

Results:

After screening the titles and abstracts and thoroughly reading the full text, we obtained 13 studies with little risk of bias that incorporated 1744 middle-aged obese participants with mild to severe OSAS. The studies were published from 1994 to 2012. Treatment durations varied from 1 to 24 weeks. The effect sizes of attention, vigilance, processing speed, working memory, memory, verbal fluency, and visuoconstructive skills domains were −0.10 (P = 0.24), −0.12 (P = 0.04), −0.08 (P = 0.16), 0.00 (P = 0.95), −0.04 (P = 0.30), −0.06 (P = 0.34), and −0.01 (P = 0.92), respectively.

Conclusions:

Cognition partially improved in patients with OSAS after CPAP treatment. The only domain with significant improvement was vigilance. Rigorous randomized controlled trials need to be performed to obtain clear results.     

Intravenous paracetamol versus intramuscular pethidine in relief of labour pain in primigravid women

Background:

Intramuscular pethidine is one of most common opioids used for labour analgesia. There are a number of concerns in the literature regarding the use of pethidine. The aim of this study is to compare analgesic efficacy of paracetamol with pethidine for labour pain in normal vaginal delivery.

Materials and Methods:

In this single-blinded, randomised control trial, 80 primigravid singleton women with full-term pregnancy candidate for normal vaginal delivery, were entered the trial and divided in to pethidine (A) and paracetamol (B) groups. At the time of admission, age and body mass index of mother and gestational age based on last day of period were recorded. In both groups, intravenous promethazine and hyoscine were administered to each patient at the first stage of delivery. From beginning of active phase of delivery, patients in group A received 50 mg intramuscular pethidine injection. At the same time patients in group B, received an intravenous solution infusion containing 1000 mg paracetamol and 300 cc of normal saline. After child birth, average labour pain was assessed using Visual Analogue Scale (VAS) by direct questioning from patient in both groups.

Results:

After patients'' selection, 19 individual omitted during study due to exclusion criteria and finally 30 patients in paracetamol group and 31 patients in pethidine group remained to enter the trial. There was no significant difference in age and BMI of mothers between both groups (P > 0.05). Maternal age and labour duration in paracetamol group had no meaningful difference with maternal age and labour duration of patients in pethidine group (P > 0.05). The average VAS pain score was significantly lower in paracetamol comparing to that of pethidine group (8.366 out of 10, 9.612 out of 10, respectively, P < 0.001).

Conclusion:

It is concluded that intravenous paracetamol is more effective than intramuscular pethidine to relief labour pain in normal vaginal delivery.     

Beneficial effects of low dose Musa paradisiaca on the semen quality of male Wistar rats

Background:

This study aimed at determining the effects of administration of mature green fruits of Musa paradisiaca on the semen quality of adult male Wistar rats.

Materials and Methods:

The animals used for the study were grouped into three: the control group, given 2 ml of double distilled water, a low dose group given 500 mg/kg/day and a high dose group given 1000 mg/kg/day of the plantain fruits, which was made into flour, and dissolved in 2 ml of double distilled water for easy oral administration.

Results:

Significant increment in the semen parameters was noticed in animals that received a lower dose of the plantain flour, but those animals who received the high dose had marked and very significant reduction in sperm cell concentration and percentage of morphologically normal spermatozoa.

Conclusion:

Musa paradisiaca should be consumed in moderate quantities in order to derive its beneficial effects of enhancing male reproductive functions.     

Effect of Hyperbaric Oxygen on the Growth of Intracranial Glioma in Rats

Background:

Numerous studies have confirmed that hyperbaric oxygen (HBO) in combination with radiotherapy or chemotherapy may increase the efficacy of radiotherapy or chemotherapy in patients with glioma. However, whether HBO therapy alone may inhibit or promote the growth of malignant tumors remains controversial. This study aimed to investigate the effect of HBO on the growth of glioma in rats, and the impact of HBO on the expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1-alpha (HIF-1α), angiogenesis, and apoptosis of glioma cells.

Methods:

Male Sprague–Dawley rats were treated with or without HBO after glioma cell inoculation and followed for up to 16 days postinoculation. Rats were randomized to receive bilateral forelimb function tests (n = 20 per group) and head magnetic resonance imaging (n = 5 per group). Differences between HBO and control groups were tested using 2-sample independent t-tests and changes over time within treatment groups were analyzed using a repeated measurement analysis of variance with Bonferroni correction. The effect of HBO on the expression of VEGF, HIF-1α, von Willebrand factor, angiogenesis, and tumor cell apoptosis were also examined (n = 5 per group).

Results:

Forelimb function scores were reduced in both HBO-treated and control groups. HBO-treated rats had significantly larger tumor volume and more water in the cerebellum compared with control rats. The intratumoral expression of VEGF was significantly higher in HBO-treated rats compared with control rats (23.2% vs. 13.3%, P = 0.002). HIF-1α was significantly increased in HBO-treated rats compared with controls in the expression of both intratumoral (72.7% vs. 54.9%, P = 0.001) and peritumoral (2.6% vs. 1.9%, P = 0.003) cells. The intratumoral microvessel density (MVD) was significantly higher in the HBO group (15.6 vessels/field vs. 4.4 vessels/field, P < 0.001), and the peritumoral MVD was not significantly different between the two groups (P > 0.05). Apoptosis was significantly lower in HBO-treated rats compared with controls (44.4% vs. 82.8% for intratumoral; 10.1% vs. 77.5% for peritumoral, both P < 0.001).

Conclusions:

The current results demonstrate that HBO alone may promote tumor growth, and is therefore not suitable to treat patients with gliomas with neurological deficits or disorders with HBO alone. If HBO must be used as a mean of rehabilitation, it is recommended that HBO should be combined with radiotherapy or chemotherapy.     

Protective Effects of Salubrinal on Liver Injury in Rat Models of Brain Death

Background:

Previous studies have indicated that endoplasmic reticulum stress participates in and mediates liver injury and apoptosis in brain-dead (BD) rats. In this study, we observed the effect of salubrinal (Sal, Sigma, USA) on liver cells in BD rats and explored its relevant mechanisms.

Methods:

Thirty Sprague–Dawley rats were equally randomized into three groups: BD group, Sal group, and DMSO group. The BD models were established by increasing intracranial pressure in a modified, slow, and intermittent way. In the drug groups, Sal was administered 1 h before the induction of BD. After modeling was completed, the blood and liver samples were harvested. CHOP and Caspase-12 mRNA expression was detected using quantitative polymerase chain reaction. PKR-like ER kinase (PERK), P-eukaryotic translation initiation factor 2α (eIF2α), eIF2α, CHOP and caspase-12 expression was detected using western blotting (WB). CHOP and caspase-12 distribution and expression in liver tissues were determined using immunohistochemistry (IHC). Alanine aminotransferase and aspartate aminotransferase level were detected using an automatic biochemical analyzer. Hepatic cell apoptosis was detected using TUNEL. The results were analyzed using Quantity-one v4.62 software (Bio-Rad, USA).

Results:

CHOP and caspase-12 expression and PERK, eIF2α, and P-eIF2α protein expression showed no significant difference between BD group and DMSO group. Compared with BD group, Sal group had a significantly higher P-eIF2C level and a lower P-PERK level 2 h and 6 h after BD (P < 0.05). However, eIF2α expression showed no significant difference (P > 0.05). After the Sal treatment, CHOP and caspase-12 mRNA expression significantly decreased 4 h after BD (P < 0.05). WB and IHC indicated that CHOP and caspase-12 expression also significantly decreased after Sal treatment. Sal was associated with improved liver function and decreased hepatic cell apoptosis.

Conclusions:

Sal can significantly reduce apoptosis in hepatic cells of BD rats. This protective effect may be achieved via the PERK-eIF2α signaling pathway.     

Elevation of serum pancreatic amylase and distortion of pancreatic cyto-architecture in type 1 diabetes mellitus rats treated with Ocimum gratissimum

Background:

Diabetes mellitus has been shown to cause severe impairment in exocrine pancreatic function and cyto-architecture. Ocimum grattissimum has been reported to lower blood glucose levels in experimental diabetic animals. This study, therefore, aims to investigate if treatment with O. grattissimum can alleviate these pancreatic complications of diabetes mellitus. The phytoconstituents and median lethal dose of the plant extract were determined.

Materials and Methods:

Eighteen rats were divided into three groups of six rats each. Diabetes mellitus was induced by single intraperitoneal injection of 65 mg/kg streptozotocin. Group 1 was the control and were given normal feed only; Group 2 was of diabetic untreated rats, while Group 3 was O. grattissimum-treated diabetic rats at a dose of 1,500 mg/kg. After 28 days, blood was collected by cardiac puncture of the anaesthetised animals and the serum was obtained for analysis of serum pancreatic amylase. Permanent preparations using routine biopsy method were employed for histological preparations.

Results:

Results showed that the level of pancreatic serum amylase in the test groups (diabetic and diabetic-treated) were significantly higher (P < 0.05) than the control group, while the diabetic-treated group was significantly lower than the diabetic group. Atrophic acinar tissue without β-cells was noted in the diabetic and diabetic-treated groups. Patchy areas of necrosis, oedematous interstitium, haemorrhagic and necrotic acinar cells were present in diabetic-treated groups.

Conclusion:

Direct association exists between the hyperglycaemic state caused by diabetes mellitus and the elevation of the serum pancreatic amylase and distortion of pancreatic cyto-achitecture. O. grattissimum-treatment reduced serum pancreatic amylase level to near normal and limit the extent of structural damage.