Pathobiology Research
Year:2002 | Volume:5 | Issue:1|Papers Count:19

Purpose: Recognition of objects by our visual system is independent of the size of their retinal image. But the neural basis of size invariant object recogntion is not clear. Inferotemporal area TE is thought to be critical for invariant recognition of visual objects. Stimulus shape selectivity of neuronal responses is not significantly different between the posterior and anterior parts of TE, but invariance to other stimulus attributes may develop within TE. In the present study, we examined the correlation between the degree of invariance of TE cells to visual stimulus size changes and the anterior-posterior positions of the cells in anesthetized macaque monkeys.Materials and Methods: For each cell the simplest stimulus that evoked the maximum response was first determined as the optimal stimulus. Then effects of changes in the size of the optimal shape on the cell responses were examined. The test range of size was at least 4 octaves.Results and Discussion: There was a positive correlation between the size invariance (measured as the tuninng bandwidth at half the maximum response) and anterior posterior positions of the cell. Cells with wide size tuning were only found in the anterior TE while cells with relatively selective size responses were found through the anterior-posterior extent of TE. These findings suggest that the size invariance develop within the neural circuits of anterior TE.

Purpose: Electromyography is a common method used to study the muscles and their functions by many researches in different disciplines such as physiology, biomechanics, biomedical cngineering, physiotherapy and so on. In most of the studies researchers locate recording electrodes on muscles by refering to other previous works. Hence there is a controversy on the electrode locations in reports. In this paper we propose a new method to find the best electrode placement location on trapezius, deltoid and pectoralis major muscles with reference to their motor points.Materials and Methods: To do this, we first found motor points of muscles using electrical stimulation. Then we compared our results with reports found in other works.Results and Discussion: Results indicate that the motor point found in our research has different locations in trapezius and deltoid muscles, but the location of motor points of pectoralis major coincides with other reports. The best electrode positions on muscles are detected with reference to motor points in different parts of muscles. These locations have a small difference with the locations reported by others. Furthermore we found that if the pair of electrodes are located along the direction of muscle fibers, the recorded EMG will have a higher amplitude.

Purpose: The main objective of this correlative descriptive study was the assessment of probable conversions in tuberculin negative individuals after that they were in contact with the patients afflicted with tuberculosid in a definite period of time.Materials and Methods: The study group consisted of 143 family members of patients with active tuberculosis who had positive smears and had been referred to Kermanshah Center of Tuberculosis Control from March to June 1999. First Mantoux test was carried out on all the individuals participated in the study. 67 tuberculin negative cases were followed and two more assessment was carried out, once 3weeks and again 3 months after the test using two other mantoux tests and clinical examinations. A chest x-ray was also requested for the tuberculin converted persons. Data collection was done using observational technique, interview form and check list.Results and Discussion: There was a positive tuberculin test in 49 percent of the study group, who were excluded from the study. During the follow up of the PPD negative cases there was a tuberculin conversion of 14.9% and 28.1% of the cases at the end of the 3rd week and the 3rd month. A chest x-ray was requested for there cases and the radiographic examination indicated a primary TB in one of the cases for whom medical treatment was started. For the other tuberculin converted cases chemoprophylaxis was ordered. For the children under five years old who had received INH prophylaxis there " was no conversion (p<0.05).There was also a significant correlation between the tuberculin conversion rate and the number of family members being in contact with the patients for a long period of time and the degree of the positivity of sputum smear in patients. Age, gender, education, BCG vaccination and living place did not have any statisticaly significant correlation with the tuberculin conversion rate.Thus, considering the evident proof of efficacy of chemoprophylaxis in this study we suggest that for any individual who is in contact with smear positive pulmonary TB, a tuberculin test has to be made and if a case of tuberculin coversion is encountered chemoprophylaxis should be started for him/her.

Purpose: Iron deficiency anemia (IDA) is the most prevalent nutritional deficiency throughout the world. Adolescent girls are considered as the high risk group consisting of a high proportion of the IDA. In patients in all age groups, including the adolescent girls, low dietary iron intake is the major cause of IDA. In this study we attempted to determine whether a nutritional educational program could effectively reduce the prevalence of iron deficiency among adolescent girls.Materials and Methods: For this purpose a pre -and post- clinical trial study was designed and 43 girls from a high school in Tehran, who had some criteria for inclusion and were on the negative iron balance based on the labratory data (Hb, Hct, MCV, MCH, MCHC, serum iron, TIDC, percent of saturation of TIDC & serum ferritin), were selected. Then the required data includings socioeconomic characteristics, knowledge, attitude, practice and nutritional habits were gathered. Three months after designing and performing the educational programs, the post test was done.Results and Discussion: As a result of this intervention, a significant change in the knowledge, attitude and practice was observed towards the improvement of the quality of iron bioavailability in the diet of adolescent girls. The mean of the daily heme iron intake was increased from 43% mg to 86% mg (P<0.000). Comparison of the biochemical findings of iron status indicated an increase in the ironstoragelevelwith23%of the girls reaching to the range of the normal group (P<0.000). Therefore, it seems that the adolescent girl education could be an effective strategy for improving the nutritional habits of adolescent girls to increase dietary iron, preveont iron deficiecy anemia and reduce its' complications.

Purpose: HIV -1 enters into target cell by the use of chemokine receptor CC-CKR-5. The mutant gene of this coreceptor (CCR5Δ32bp) codes a truncated protein which does not express on the cell surface play its' coreceptor function. According to the recent studies, homozygote individuals with mutant gene are immune to HIV-IR5 and hetrozygote individuals show a kind of slow development of AIDS. Due to its important function the mutation frequency of this gene has been studied in different human population.Materials and Methods: To study the existence of this mutation the PCR-ELISA technique was used for its sensitivity, specificity and speed.Results and Discussion: Genomic DNA was extracted from different blood samples. By PCR and specfic primers, a735bp fragment from CCR5 gene was amplifed, and the mutation was detected by two labeled probes (CCR-W to wild allele, CCR-M to mutant allele).CCR-W is complementary to wild allele including 32bp mutation site. The second probe (CCR-M) is complementary to the deleted region of mutant allele. For PCR-ELISA method, PCR product was labeled by digoxigenin and the 3' end of CCR Wand CCR-M was eabeled biotin-dUTP. After hybridization of the denatured PCR product with its complementary probe, the hybrids were captured in streptoavidine coated microtiter plate. Detection was performed by using anti-digoxiginin conjugated to HRP. The results were analyzed and the sensitivity of this method found to be (PCR-ELISA)<300 pg of human genomic DNA.

Purpose: The use of accurate and reliable bioassay methods for recombinant proteins is a key element in the production and utilization of such proteins. In this research we have tried to present a reliable method for the G-CSF bioassay. HL-60 cells belonged to human leukemia cells are capable to be differentiated into macrophages or neutrophils. When stimulated by different agents like DMSO, RA and cAMP, HL-60 cells are differentiated into neutrophils, while interferon and phorbol ester differentiate them into macrophages.Materials and Methods: In this study HL-60 cells were first cultured in flasks. Then 2x 105cell/m1 of them were selected and. 100µ1 of this cell suspension was transferred to a 96-well microplate. Then proper dilution of DMSO and RA was prepared and added to the cell suspension (1.3% and 0.1 µM respectively) and incubated at 37°C and 5% CO2 atmosphere. Using RA and DMSO, the cell were transferred from the proliferative phase to the differentiativephase. Then various concentrations of GCSF were added to these treated cells and incubate (at 37°C and 5% CO2 atmosphere for two days. The MTT assay was used to measure the reversal rate of the cells from the differentiative to the proliferative phase.Results and Discussion: The cell proliferation was evaluated by mitochondrial S.T.R. enzme system through the reduction of MTT to Furmazan. The results showed that this method is reliable for the G-CSF bioassay.

Purpose: Human granulocyte colony-stimulating factor (hG-CSF) is a growth factor that stimulates the proliferation and differentiation of granulocyte progenitor cells, and neutrophilic granulocyte colony formation of bone marrow cells. This factor also induces terminal differentiation of some leukemic myeloid cells. HuG-CSF is produced in human monocyte and macrophage in response to bacterial endotoxin, and also in human cell lines such as oral cavity carcinoma (CHU-2) and bladder carcinoma (5637). The aim of this research was to extract total RNA from stimulated human monocyte cells, synthesis of hG-CSF ds cDNA, and cloning of cDNA in an appropriate cloning vector.Materials and Methods: First, monocyte cells were isolated from normal human peripheral blood. These cells were cultured and simultaneously stimulated by LPS and hIFN-γ. Total RNA was extracted from cells, and hG-CSF signal sequence-containing cDNA and signal sequence-free cDNA were synthesized with specific primers and based on RT-PCR method. Also, both of the mentioned cDNAs were sythesized by extracting total RNA from cultured 5637 carcinoma cells. Both of the monocytic cDNAs were confirmed by the restriction enzyme of StyI that forms three distinct fragments on gel electroforesis. Then, signal sequence-containing cDNA was inserted into the cloning vector of pBluescriptIISK and cloned in E.coli (TOP10F' strain).Results and Discussion: After screening, correct colonies were selected, and recombinant vector was extracted from transformed cells and confirmed by the restriction enzymes of EcoRI, BamHI, NcoI and StyI. Finally, the correct recombinant vector was selected and sequenced. After confirmation of the nucleotide sequence of the cloned cDNA, the signal sequence-free cDNA was synthesized with specific primers, recombinant vector as a templet, and by PCR; and was inserted into pBluescriptIISK and cloned in TOP10F'. Then, the correct clone was selected and confirmed by restriction enzymes.

Purpose: The glucose oxidase (GOD) catalyses oxidation of β-D- glucose to D-gluconic acid and H202. Aspergilluse niger is one of the most fungal sources used for the GOD production. The present report deals with the optimization of culture conditions for the GOD enzyme production, its' purification from culture broth and cell extract, characterization of the purified enzyme and comparison of this enzyme with the standard enzyme.Materials and Methods: Seventeen samples of Aspergilluse niger were screened for the GOD activity. Samples were cultured in a non specific diagnostic medium. Then the GOD overproducer samples were detected in a specific diagnostic medium and the NRRL-3 strain was selected for the optimization of the GOD synthesis in the submerged culture optimized with the "ONE AT A TIME" method. After the optimization, the enzymatic specific activity reached to 0.22 (from 0.172). For the production of the GOD in large scale, NRRL-3 was cultured in the optimized medium in a bioreactor. Mycelium and postculture liquid medium were used for the enzyme purification. Results and Discussion: The GOD was purified by a combination of ion exchange and filtration chromatography with approximately a 90-fold enrichment in the specific activity and an enzyme recovery of 9%. The purified enzyme had an apparent native molecular weight of 160 KDa and a denatured molecular weight of 80 KDa determined by the SDS-PAGE. The optimum value of pH for the enzyme activity was between 5.6 and 5.8. The enzyme was severely by O-phtalate (10 mM) and partialy by Ag2+,CU2+, Hg2+,hydrazine and hydroxylamine (all in 10mM). The enzyme Km value for glucose oxidase was 37 mM.

Purpose: The influence of 5% carbohydrate (Cho) versus placebo (P) beverage consumption on the immune and hormonal responses of athletes to 1 hour cycling (approximately with 75% V02 max) was studied.Materials and Methods: Thirty six athletes who paticipated in this study were randomly allocated to three groups (Cho, N=15; P, N=11; control, N=10). Subjects received Cho or P beverages before, during and after the cycling. Blood samples were collected before and 15-20 minutes after the cycling. Results and Discussion: The level of cortisol and leukocyte was significantly lower after the cycling in the Cho compared to the C and P groups (P≤0.002, p≤0.043; respectively). There was no significant variation in the pattern of changes in neutrophils, lymphocytes, cd8+and cd56+cells and plasma glucose after the cycling. The level of cd3+and cd4+cells was significantly higher in the Cho compared to the C and P groups(p≤0.004, P≤0.01 respectively).In conclusion, consuming carbohydrate before and during the exercise attenuates the rising rate of cortisol stress hormone and appears to limit the degree of exercise induced immunosuppresion. In other words this data indicates that the physiological stress to immune system is reduced when enduring athletes use carbohydrate beverages before, during, and after a prolonged and intense exercise. However, the clinical significance of the carbohydrate induced effects on the endocrine and immune systems needs further research.

Purpose: Liver diseases such as hepatitis C virus (HCY) are one of the most common complications in renal transplantated patients. In order to clarify the changes in liver enzymes after renal ransplantation, we performed an observational and cross-sectional study.Materials and Methods: One hundred and eighty nine patients with renal TX inclucing 123 (65.1%) male and 66 (34.9%) female, participated in our study. Patrients having an ALT 1.5 time more than the normal level and a bilirubin more than 2 mg/d1 were considered abnormal. We followed all the patients at least for 9 months with a follow-up mean time of 42.5±29months.Results and Discussion: The liver tests were abnormal in 78 patients (41.2%) from which 41(52.6%) showed a transient rise in the first month after the TX and this rising was not repeated again. In 93% of the patients, the ALT level was 5 times lower than the normal level. These patients compare with the other group who showed no rising in the liver tests, had a higher dialysis duration (P<0.02).Twenty three patients (29.5%) had sustained rising in the liver tests (more than 6 months) from whom 10 patients (43.5%) were HCV+, 2 patients (8.7%) were HBV+ and 2 patients (47.8%) had unknown causes. Fourteen patients (17.9%) showed a transient rising in the liver tests in other months (not in the first month) because of different causes such as: stone, drug poisoning with CYA, INH or rifampin. Prevalance of HCV was observed in 10 patients (10.6%). The HCV+ patients had more dialysis duration and more injected blood units, than the HCV- patients (P<0.04 & P<0.01 respectively). Fifty percent of the HCV positive patients had a sustained elevation in their liver enzymes. The changes in liver enzymes is more common in the first month after the transplantation because of the immunosupresive drugs used in the first month. Gradually the amount of drugs is decreased until the second month when the dose reaches to the maintenance level, following which the transient changes of the liver enzymes reach to the normal level.

Purpose: The development of hemolytic alloantibodies and erythrocyte autoantibodies complicates transfusion therapy in thalassemic patients .This research has been carried out to determine and identify red cell alloantibodies in multitransfused patients with thalassemia.Materials and Methods: Three hundred patients were studied with 11.3% of them being under 6, 63.7% between 6 and 15, and 25 percent over 15 years old. All of the patients received blood matched for the ABO system and Rh-D antigen.Results and Discussion: Twenty seven patients had red cell antibodies (9%). From the 27 patients who had alloantibody, 14 had one antibody (51.9%), 9 had two antibodies (33.3%) and 4 had three antibodies (14.8%). A total of 44 alloantibadies were found in these patients from which twenty one antibodies belonged to the Rh system (47.7%), 15 to Kell (34.1%), 4 to MNSs (9.1%),3 to Kidd (6.8%) and 1 to DuffY system (2.3%). In patients whose blood transfusion had started after the age of 3, the percentage of patients with alloantibodies was higher than those whose transfusion started before the age of 3 (15.1% VS. 4%, P<0.05). There was no signifcant relation between the age and sex of the patients and the existance of alloantibody and also between the number of transfusions and the existance of alloantibody in the patients serum. Alloimmunization causes common serious complications in major thalassemi. patients, who are affected by donor-recipient RBC antigen mismatch and immunological factors.

Purpose: Recent Progress in multimooal imaging makes it possible to acquire several images from different physical properties of individual subject. Data fusion, image registration and especially image warping of these different images and sequential images have wide range of applications in medical diagnosis and treatment. Many registration techniques use interpolating function as a basis to map one image to another. Because of space variant and nonlinearity properties of imaging system, local warping algorithm improves performance of mapping.Materials and Methods: In this research we have developed a new method for local warping based on voronoi images.This method employs weighted average of partially warping function of distinct sets of landmark points.The method was tested on a large database including real as well as simulated magretic resonance images and its" results were compared with a standard benchmark sotware (AIR). Results and Discussions: Results indicated that our method has an excellent ability to compensate several geometrical distortions compare with the global warping methos.

Purpose: Wide spread efforts have been mode to facilitate and compare cryopreservation methods needed for the long-term conservation of embryos. Improving the embryo's culture system is another purpose of many researchers.Co-culture and sequential media systems can improve the developmental rate of vitrified and non-vitrified embryos separately. The aim of this research was to study, the effect of simultaneous use of vero cell co-culture and sequential media on the development of one-cell mouse embryos.Materials and Methods: One-cell mouse embryos were taken from NMRI mice with vaginal plaque, by the flushing method 26 hours after the intraperitoneal injection of hCG. Half of the embryos were vitrified by 40% ethylene ghycol solution (EFS 40%), then thawed and transferred to "R1-R2"(experiment group I) and "R1-R2 + Vero" (experiment group 2) media. The remaining embryos weretransfered to the same media as the non-vitrified control group. The data was recorded within 120 hours of the cultivation period and analyzed using the Chi square and Fisher tests.Results and Discussion: The results were as fallows: in vitrified embryos, the developmental rate in the "R1-R2 +Vero" group was higer than the "R1-R2" alone and the co-culture improved the developmental rate of the embryos significantly. But there was no significant difference between the developmental rate of the co-cultured and the non co-cultured embryos in the non vitrified group. Therefore, simultaneous use of co-culture system and sequential media has not any positive effect on the development of non vitrified embryos. But in vitrified embryos it improves the development of embryos.

Purpose: This study was designed to analyze the outcomes of labor in uncomplicated, singleton pregnancies with reliable gestational age having their deliveries between 37-42 weeks.Materials and Methods: Using a cohort study, 206 women having their deliveries after 256-280 days of gesiation (37-40 weeks) were compared with 185women having their deliveries after 281-294 days of gestation (40-42 weeks) who were admitted in Shohada, Hazrat Zeinab (SA) and Mahdieh Hospitals. The main variables analyzed were the meconium stained aminionic fluid, apgar score, fetal distress, labor induction, method of delivery, shoulder dystocia, and macrosomia.Results and Discussion: Meconium stained amnionic fluid (15.3% vs 10.2%, P=0.000) induction of labor (40.4% vs 18% P=0.000),cesarean section (27.2% vs 15%,P=0.000) instrumental delivery (3.2% vs 0.48% (P=0.000) were found to be significantly higher in the 40-42 weeks group compared to the 37-40 week group. Fetal distress (10.27% vs 5.8%) apgar score less than 7 in 5 and 10 minutes (0.6% vs 0.4%, P>0.05) were not significantly different in the two groups. There were no macrosomia, shoulder dystocia and stillbirth in the both groups. Maternal age and parity did not alter the risk of post date pregnancies, even though the history of post date pregnancy is a risk factor for post date pregnancy.

Purpose: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common human enzymopathy. About 7.5% of the world population carry a gene for G6PD deficiency. The highest gene frequency is found among the population living in places where the incidence of malaria is high.Materials and Methods: In this study we evaluated the level of G6PD deficiecy in 1097 primary school boys in two Baluch and Sistan tribes by the fluorescent spot method.Results: The G6PD deficiency was 19.3% and 5.8% in Baluch and Sistani tribes respectively. There was a significant difference (P<0.01) between Sistanies and Baluches regarding the percentage of the G6PD deficiency. The incidence of the G6PD deficiency in Baluch tribe was the same as that of the southern neighboring countries and the countries in which there is a high incidence of malaria. These results showed a homogenecity in the distribution of the G6PD gene in Baluchestan Province of Iran (at the center and south of the province) and the southern neighboring countries. It also supports the theory that malaria can lead to the frequency increase of the G6PD deficiency.

Purpose: This quasi experimental clinical trial was performed to study the effect of pulsed ultrasound (PUS) on the treatment of chronic maxillary and frontal sinusitis.Materials and Methods: In this study 32 patients (20 men and 12 women) with the mean age of 34.9 years who were reffered to the physiotherapy clinic by the ENT clinic of Hazrat Rassol Hospital were treated for ten sessions (every other day) with the PUS (1=0.5-1 W/cm 2and f=1 MHz). The patients didn't take any analgesic antibiotic, or antihistamin drugs during the treatment period.Results and Discussion: The results showed that in 85.5% of the patients all signs and symptoms were improved. All the common symptoms, especially nasal discharge, nausea, pain, coughing and PND were significantly improved. The highest improvement rate was seen in patients having a disease history of 5-9 years. Therefore, it seems that the PUS is effective for the treatment of chronic maxillary and frontal sinusitis.