جواد فحانیک بابایی

Alzheimerchr('39')s disease (AD), is the most common neurodegenerative disease that is associated with cognitive and behavioral disorders and the rapidly increasing prevalence. In addition to its detrimental effects on learning and memory, AD affects the mitochondria as a vital organ of the cell as well as the hippocampal tissue that is the site of learning and memory. In this study, we investigated the concomitant effects of streptozotocin (STZ) on spatial memory, mitochondrial production of reactive oxygen species (ROS), and hippocampal β-amyloid plaques in rats.

Animals were randomly divided into control, sham and STZ groups receiving streptozotocin 2, 3, 4 and 5 mg/kg through intracerebroventriclular (icv) injection. Learning and memory of rats was examined 14 days later by Morris Water Maze (MWM) test. Moreover, mitochondrial ROS in the brain and β-amyloid plaques in the hippocampus were evaluated.

STZ 3 mg/kg (single dose, icv) was found the effective dose for impairing learning memory in the shortest possible time (14 days). Using Congo red staining, a number of amyloid beta plaques were observed in the hippocampus. Mitochondrial ROS production also increased by this dose of STZ.

Behavioral, biochemical, and histological findings of the present study suggest STZ 3 mg/kg icv injection to rats as one of the acceptable animal models of AD.

Chloride channels are present in mitochondrial membranes where they regulate volume and acidity of cells and organelles, cell signaling, and protective mechanisms of the cells. We have previously reported the presence of a 301 pS chloride channel in mitochondrial inner membrane of the rat brain. In this work we characterized biophysical properties of a new chloride channel in the mitochondrial inner membrane of the rat brain.

The rat brain was harvested and homogenized in the MSE-nagarase lysis buffer. The homogenate was centrifuged in 3 steps in MSE-digitonin, H2O, Na2CO3, respectively. Vesicles of mitochondrial inner membrane were then extracted in MSE solution. The membrane lipid L-α-Phosphatidylcholine was extracted from fresh egg yolk. Bilayer lipid membrane was formed in a 200 μm diameter hole.  All recorded data were filtered at 1 kHz and stored at a sampling rate of 10 kHz for offline analysis by PClamp10 software. Statistical analysis was performed by Markov's noise-free single channel analysis.

Channel incorporation into planar lipid bilayer revealed a selective anion channel with a conductance of 158 pS in 200 mM KCl cis/50 mM KCl trans electrolyte. The channel open probability appeared to be voltage dependent as the channel was very active at the voltages between ± 20 mV. Adding the chloride channel inhibitor DIDS in the side corresponding to the cell internal medium (cis) caused a strong inhibition of the channel activity.

Our results indicate the presence of a chloride channel in the mitochondrial inner membrane of the rat brain. This channel might play a role in maintaining proper pH level, regulation of membrane potential, ATP synthesis, and cell protection.

Recent studies have shown the presence of Cl- channels in heart and liver mitochondrial membranes. In this work, we have characterized the functional profile of a Cl- channel from rat brain mitochondria.

After removing and homogenizing the rat brain, the supernatant was separately centrifuged in MSEdigitonin, H2O and Na2CO3 and mitochondrial inner membrane vesicles were obtained in MSE solution. L-α- Phosphatidylcholine (membrane lipid) was extracted from fresh egg yolk. Bilayer lipid membranes were formed in a 150 μm diameter hole. All recordings were filtered at 1 kHz and stored at a sampling rate of 10 kHz for offline analysis by PClamp10. Statistical analysis was performed based on Markov noise free single channel analysis.

Brain mitochondrial inner membrane preparations were subjected to SDS-PAGE analysis and channel protein reconstitution into planar lipid bilayers. Western blotting and antibodies directed against various cellular proteins revealed that the mitochondrial inner membrane fractions did not contain specific proteins of the other subcellular compartments except a very small fraction of endoplasmic reticulum. Channel incorporation into the planar lipid bilayers revealed an anion selective channel with a conductance of 301 pS in 200 mM KCl cis/50 mM KCl trans. The channel open probability appeared to be voltage dependent and the channel was active between the voltages of -40 and +20 mV. Adding 10 μM DIDS to the side corresponding to the cell internal medium caused a strong inhibition of the channel activity.

This channel is likely to be involved in maintaining proper pH, membrane potential, ATP synthesis, and cell protection.

Previous studies have shown that morphine consumption during pregnancy may delay embryo development or cause abnormal nervous system function. This study focused on the effects of maternal morphine consumption on olfactory cortex development in Wistar rats.

In this experimental study, 12 wistar rats (250-300g) were used. The experimental group received morphine solution (0.05 mg/ml) where as the control group received tap water. On the 19 th day the pregnant rats were killed by chloroform, and the embryos were removed surgically. The embryos were fixed in formalin 10% for 2 weeks. Then the weight of fixed embryos was calculated by a digital balance. In addition, animal sizes including Crump-Rump (C-R), Dorsal-Ventral (D-V), Frontal-Occipital (F-O), Abdominal Width, and Biparietal Axis length were measured by a caliper. Tissue processing, sectioning and staining (both hematoxylin and eosin (H&E) and silver nitrate staining) were then applied for the embryos. The sections were examined for olfactory cortex development by light microscope.

Reductions in D-V lengths as well as embryonic weight was observed in the experimental group (p<0.01, p<0.05). On the microscopic view, a growth retardation was observed in all three olfactory cortex layers in the experimental group. In addition cell compression in cortex layers and neuronal process was also reduced in the experimental group (p<0.05).

This study showed that oral morphine consumption during pregnancy causes defect in the development and growth retardation in olfactory cortex region. The study also showed that oral morphine consumption reduced both the weight and length of the embryos. These defects may be the cause of behavioral problems observed in the animals who have been born to addicted mothers.

Chronic Renal Failure (CRF) is characterized by impaired renal function, which is progressive & irreversible. Most of these patients will need hemodialysis (HD) in future. Treatment of CRF with HD has many echonomical & psychiatric problem for patients & society.

The present study was carried out to investigate the reasons of chronic renal failure in hemodialysis patients in Guilan Province.

In this cross-sectional study, 414 Patients under HD were evaluated in 10 center in Guilan. Required data were obtained from doctor’s note, sonography, ECG, renal biopsy & history taking include: age, sex, how long form 1st dialysis & causes of CRF

In this study 414 cases including 213 (51.4 %) male & 201 (48.6 %) female were studied. Mean age of patients was 48.9±15.9 in initiation of HD. Results showed that the most common causes of ESRD in this region were hypertension (26.1%), glomerulonephritis (10.9%), diabetes mellitus (10.1%) renal stone (8.7%) and polycystic kidney (6.8%). Other cases such as congenital disease, lupus, Alport syndrome, trauma, bleeding during labor hemorrhagia and drugs were 10.1% and 23.4% were unknown.

The most common causes of End Stage Renal Disease (ESRD) in this region was hypertension (26.1%) and also In this study, glomerulonephritis and diabetes mellitus were second and third causes of ESRD. Also nephrolithiasis, as a cause of CRF was more common in this region. This can be related to probable high-risk prevalence of nephrolithiasis in this region. Causes of CRF between two sexes or age >40 and <40 were different significantly. (p<0.05)