The wound healing effect of polycaprolactone-chitosan scaffold coated with a gel containing Zataria multiflora Boiss. volatile oil nanoemulsions

AIMS

Thymus plant is a very useful herbal medicine with various properties such as anti-inflammatory and antibacterial. Therefore, the properties of this plant have made this drug a suitable candidate for wound healing. In this study, hydroxypropyl methylcellulose (HPMC) gel containing Zataria multiflora volatile oil nanoemulsion (neZM) along with polycaprolactone/chitosan (PCL-CS) nanofibrous scaffold was used, and the effect of three experimental groups on the wound healing process was evaluated. The first group, HPMC gel containing neZM, the second group, PCL-CS nanofibers, and the third group, HPMC gel containing neZM and bandaged with PCL-CS nanofibers (PCL-CS/neZM). Wounds bandaged with common sterile gas were considered as control.

METHODS

The nanoemulsion was synthesized by a spontaneous method and loaded into a hydroxypropyl methylcellulose (HPMC) gel. The DLS test investigated the size of these nanoemulsions. A PCL-CS nanofibrous scaffold was also synthesized by electrospinning method then SEM and contact angle tests investigated morphology and hydrophilicity/hydrophobicity of its surface. The animal study was performed on full-thickness skin wounds in rats, and the process of tissue regeneration in the experimental and control groups was evaluated by H&E and Masson's trichrome staining.

RESULTS

The results showed that the nanoemulsion has a size of 225±9 nm and has an acceptable dispersion. The PCL-CS nanofibers synthesized by the electrospinning method also show non-beaded smooth fibers and due to the presence of chitosan with hydrophilic properties, have higher surface hydrophobicity than PCL fibers. The wound healing results show that the PCL-CS/neZM group significantly reduced the wound size compared to the other groups on the 7th, 14th, and 21st days. The histological results also show that the PCL-CS/neZM group could significantly reduce the parameters of edema, inflammation, and vascularity and increase the parameters of fibrosis, re-epithelialization, and collagen deposition compared to other groups on day 21.

CONCLUSION

The results of this study show that the PCL-CS/neZM treatment can effectively improve wound healing.

The potential roles of Th17 cells in the pathogenesis of oral lichen planus

BACKGROUND

Oral lichen planus (OLP) is a T cell-mediated chronic autoimmune disease, whose pathogenesis and etiology are not entirely understood. OLP is characterized by subepithelial lymphocyte infiltration and elevated intra-epithelial lymphocytes. The majority of lamina propria lymphocytes are CD4⁺ T cells. CD4⁺ helper T (Th) cells play a crucial role in activating CD8⁺ cytotoxic T cells (CTLs) through interactions and cytokine production. Th1 and Th2 cells are well-accepted to be associated with OLP pathogenesis. However, OLP treatment is challenging yet, the more information we have about the pathology of OLP, the easier it will be treated. With the discovery of Th17 cells in recent years and the demonstration of their role in autoimmune disease, many researchers started to investigate the role of Th17 in the pathogenesis of OLP.

METHODS

To make up this review, studies covering the role of TH17 in different types of lichen planus were selected from major databases.

RESULTS

As we review in this article, Th17 cells and their signature cytokines play an important role in OLP pathogenesis. As well, utilizing some anti-IL-17 antibodies showed promising results in improving the disease; however, more studies are still needed to better understand and treat OLP.

A Novel Minimally Invasive technique for dilatation of hepaticojejunostomy stricture: A case report

Using a nephroscope in a laparoscopic operation to relieve the hepaticojejunostomy stricture (HJS) by transjejunal dilatation is a minimally invasive and applicable method. It can be used as the first step for such patients.

Using a nephroscope in a laparoscopic operation to relieve the HJS by transjejunal dilatation is a minimally invasive and applicable method. It can be used as the first step for such patients.

Effect of PCL nanofiber mats coated with chitosan microcapsules containing cinnamon essential oil for wound healing

INTRODUCTION

Cinnamon is one of the most common spices that has been studied for its anti-inflammatory, antioxidant, and antibacterial properties in wound healing. The purpose of this study was to evaluate the effectiveness of polycaprolactone nanofiber mats coated with chitosan microcapsules loaded with cinnamon essential oil in wound healing.

MATERIAL AND METHODS

For this purpose, chitosan microcapsules containing cinnamon essential oil (µCS-CiZ) were prepared by ion gelation and PCL nanofibers by electrospinning. The size of the µCS-CiZ and the morphology of nanofibers were evaluated by DLS and FESEM methods. In order to evaluate wound healing, 48 rats in 4 groups of Control, µCS-CiZ, PCL, and PCL + µCS-CiZ and were examined on days 7, 14, and 21 in terms of macroscopy (wound closure rate) and histology (edema, inflammation, vascularity, fibrotic tissue, and re-epithelialization).

RESULTS

The particle size of the µCS-CiZ and the diameter of the nanofibers were estimated at about 6.33 ± 1.27 μm and 228 ± 33 nm, respectively. On day 21, both µCS-CiZ and PCL groups showed a significant decrease in wound size compared to the control group (P < 0.001). The PCL + µCS-CiZ group also showed a significant decrease compared to the µCS-CiZ (P < 0.05) and PCL groups (P < 0.05). Histological results showed further reduction of edema, inflammation, and vascularity in granulation tissue and appearance of moderate to marked fibrotic tissue in PCL + µCS-CiZ group compared with the other groups.

CONCLUSION

The results of the study showed that the combined use of PCL + µCS-CiZ indicates a synergistic effect on improving wound healing.

Individual genetic variability mainly of Proinflammatory cytokines, cytokine receptors, and toll-like receptors dictates pathophysiology of COVID-19 disease

Innate and acquired immunity responses are crucial for viral infection elimination. However, genetic variations in coding genes may exacerbate the inflammation or initiate devastating cytokine storms which poses severe respiratory conditions in coronavirus disease-19 (COVID-19). Host genetic variations in particular those related to the immune responses determine the patients' susceptibility and COVID-19 severity and pathophysiology. Gene polymorphisms such as single nucleotide polymorphisms (SNPs) of interferons, TNF, IL1, IL4, IL6, IL7, IL10, and IL17 predispose patients to the severe form of COVID-19 or severe acute respiratory syndrome coronavirus-2 (SARS-COV-2). These variations mainly alter the gene expression and cause a severe response by B cells, T cells, monocytes, neutrophils, and natural killer cells participating in a cytokine storm. Moreover, cytokines and chemokines SNPs are associated with the severity of COVID-19 and clinical outcomes depending on the corresponding effect. Additionally, genetic variations in genes encoding toll-like receptors (TLRs) mainly TLR3, TLR7, and TLR9 have been related to the COVID-19 severe respiratory symptoms. The specific relation of these mutations with the novel variants of concern (VOCs) infection remains to be elucidated. Genetic variations mainly within genes encoding proinflammatory cytokines, cytokine receptors, and TLRs predispose patients to COVID-19 disease severity. Understanding host immune gene variations associated with the SARS-COV-2 infection opens insights to control the pathophysiology of emerging viral infections.

Purinergic receptors are a key bottleneck in tumor metabolic reprogramming: The prime suspect in cancer therapeutic resistance

ATP and other nucleoside phosphates have specific receptors named purinergic receptors. Purinergic receptors and ectonucleotidases regulate various signaling pathways that play a role in physiological and pathological processes. Extracellular ATP in the tumor microenvironment (TME) has a higher level than in normal tissues and plays a role in cancer cell growth, survival, angiogenesis, metastasis, and drug resistance. In this review, we investigated the role of purinergic receptors in the development of resistance to therapy through changes in tumor cell metabolism. When a cell transforms to neoplasia, its metabolic processes change. The metabolic reprogramming modified metabolic feature of the TME, that can cause impeding immune surveillance and promote cancer growth. The purinergic receptors contribute to therapy resistance by modifying cancer cells' glucose, lipid, and amino acid metabolism. Limiting the energy supply of cancer cells is one approach to overcoming resistance. Glycolysis inhibitors which reduce intracellular ATP levels may make cancer cells more susceptible to anti-cancer therapies. The loss of the P2X7R through glucose intolerance and decreased fatty acid metabolism reduces therapeutic resistance. Potential metabolic blockers that can be employed in combination with other therapies will aid in the discovery of new anti-cancer immunotherapy to overcome therapy resistance. Therefore, therapeutic interventions that are considered to inhibit cancer cell metabolism and purinergic receptors simultaneously can potentially reduce resistance to treatment.

The effect of subdiaphragmatic vagotomy on heart rate variability and lung inflammation in rats with severe hemorrhagic shock

Background

The influence of cutting the sub-diaphragmatic branch of the vagus nerve on heart rate variability (HRV) and inflammatory reaction to severe hemorrhagic shock has not been determined prior to this study.

Methods

Male Sprague–Dawley rats were divided into four groups of Sham, sub-diaphragmatic vagotomized (Vag), subacute (135 ± 2 min) hemorrhagic shock (SHS), and sub-diaphragmatic vagotomized with SHS (Vag + SHS). Hemodynamic parameters were recorded and HRV calculated during multiple phases in a conscious model of hemorrhagic shock. The expressions of TNF-α and iNOS were measured in the spleen and lung tissues at the conclusion of the protocol.

Results

Decreases in blood pressure during blood withdrawal were identical in the SHS and Vag + SHS groups. However, heart rate only decreased in the Nadir-1 phase of the SHS group. HRV indicated increased power in the very-low, low, and high (VLF, LF, and HF) frequency bands during the Nadir-1 phase of the SHS and Vag + SHS groups, albeit the values were higher in the SHS group. In the recovery phase, the HF bands were only lower in the SHS group. After hemorrhagic shock followed by resuscitation, the expression of TNF-α and iNOS increased in the spleen and lung of the SHS group, and the expression of these genes was significantly lower in the Vag + SHS group than in the SHS group.

Conclusion

Parasympathetic activity increases during the hypotensive phase of hemorrhagic shock, whereas the cardiac vagal tone decreases in the recovery phase. Sub-diapragmatic vagotomy blunts the cardiac vagal tone during hemorrhagic shock, but its effect is reversed in the recovery phase. The vagus nerve plays a role in proinflammatory responses in the lungs and spleen in subacute hemorrhagic shock followed by resuscitation.

Laparoscopic splenectomy in patients with idiopathic thrombocytopenic purpura and very low platelet count

BACKGROUND

Chronic idiopathic thrombocytopenic purpura (ITP), is an autoimmune disease associated with a reduction in circulating blood platelets under 150±10⁹g/L which persists longer than 6 months without any specific cause. With the current study, we aimed to evaluate the efficacy and safety of laparoscopic splenectomy in ITP patients with a very low platelet count and normal coagulation status.

METHODS

From April 2007 to January 2012, laparoscopic splenectomy was performed on 60 patients with chronic ITP who could not achieve a sustained recovery after steroid therapy.

RESULTS

Patients consisted of male/female ratio of 24 (40%):36 (60%) with the mean age of 53±15.1 years. All patients had normal coagulation state even with very low platelet count (below 5×10³) before laparoscopic splenectomy. The mean operative time was 140.00±15.00 minutes. Blood transfusion was required in 10 (16.7%) and 8 (13.3%) patients before and after the operation, respectively. Preoperative transfusion of PRBC was not statistically significant between groups (P=0.265). Bleeding complications during within or after surgery was rare (5.0%). Convalescence was rapid and the mean hospital stay was 3.58±0.68 days (1-14 days) which shows that there was no significant difference in operative time and after operative hospitalization time among the three groups (P=0.070). The patients made a good uneventful recovery and were followed for at least one week who exhibited no postoperative problems.

CONCLUSION

Laparoscopic splenectomy should be considered initially in the management of ITP. Also, very low platelet count should not be contraindicated for laparoscopic splenectomy in ITP patients and sometimes perioperative platelet transfusion may be unnecessary.

Giant lipoma pediculated in the falciform ligament: A case report

Background:

The lipoma is one of the benign soft tissue tumors that occur most in adulthood. These tumors are one of the common tumors of the limbs, and rarely occur in the abdominal cavity. These masses usually grow slowly and are asymptomatic.

Case Presentation:

In this article, we present a 23-year-old woman who was referred to a doctor with complaints of abdominal pain and enlargement that occurred in the last 4 months. Following surgery and sampling, it was found that the patient had a lipoma, and the liver was a phlegmatic liver in the liver form.

Conclusion:

The recurrence and metastasis of the primary tumor histology are not always predictable, and the authors stated that all cases of individual fibrous tumors should be known as potentially malignant.

Mitigation of Radiation-induced Pneumonitis and Lung Fibrosis using Alpha-lipoic Acid and Resveratrol

BACKGROUND

Lung is a radiosensitive organ. Studies have shown that exposure of the lung to acute and high doses of radiation following inhalation of radioactive agents or an accidental radiological event may lead to pneumonitis and fibrosis, which are associated with a risk of death. So far, some agents have been studied for mitigation of pneumonitis and fibrosis following exposure of murine lung tissues to ionizing radiation. In this study, we aimed to detect the possible mitigatory effect of alpha-lipoic acid, resveratrol and their combination on mice pneumonitis and fibrosis markers following irradiation.

METHODS

25 mice were divided into 5 groups: control, radiation; radiation plus alpha-lipoic acid; radiation plus resveratrol; and radiation plus both resveratrol and alpha-lipoic acid. Mice chest regions were irradiated with 18 Gy using a cobalt-60 gamma rays source. Treatments started 24 h after irradiation and continued for two weeks. After 100 days, all mice were sacrificed and their lung tissues removed for histopathological evaluation.

RESULTS

Pathological study showed that exposure to radiation led to severe pneumonitis and moderate fibrosis after 100 days. Both resveratrol and alpha-lipoic acid, as well as their combination could mitigate pneumonitis and fibrosis markers. Although, resveratrol could not mitigate infiltration of most inflammatory cells as well as inflammation and vascular damage, alpha-lipoic acid and its combination were able to mitigate most damaged markers.

CONCLUSION

Alpha-lipoic acid and its combination with resveratrol were able to mitigate fibrosis and pneumonitis markers in mice lung tissues following lung irradiation. Although resveratrol has a protective effect on some markers, it has a weaker effect on lung injury. In conclusion, our results suggest that the combination of resveratrol and alpha-lipoic acid has a potent mitigatory effect compared to the single forms of these agents.

Heart rate variability and pulmonary dysfunction in rats subjected to hemorrhagic shock

BACKGROUND

The activity of autonomic nervous system and its association with organ damage have not been entirely elucidated in hemorrhagic shock. The aim of this study was to investigate heart rate variability (HRV) and pulmonary gas exchange in hemorrhagic shock during unilateral subdiaphragmatic vagotomy.

METHODS

Male Sprague Dawley rats were randomly assigned into groups of Sham, vagotomized (Vag), hemorrhagic shock (HS) and Vag + HS. HS was induced in conscious animals by blood withdrawal until reaching to mean arterial blood pressure (MAP) of 40 ± 5 mmHg. Then, it was allowed to MAP returning toward the basal values. MAP and heart rate (HR) were recorded throughout the experiments, HRV components of low (LF, sympathetic index), high (LH, parasympathetic index), and very low (VLF, injury index) frequencies and the LF/HF ratio calculated, and the lung histological and blood gas parameters assessed.

RESULTS

In the initial phases of HS, the increase in HR with no change in MAP were observed in both HS and Vag + HS groups, while LF increased only in the HS group. In the second phase, HR and MAP decreased sharply in the HS group, whereas, only MAP decreased in the Vag + HS group. Meanwhile, LF and HF increased relative to their baselines in the HS and Vag + HS groups, even though the values were much pronounced in the HS group. In the third phase, HR, MAP, LF, HF, and the LF/HF ratio were returned back to their baselines in both HS and Vag + HS groups. In the Vag + HS group, the VLF was lower and HR was higher than those in the other groups. Furthermore, blood gas parameters and lung histology indicated the impairment of gas exchange in the Vag + HS group.

CONCLUSIONS

The sympathetic activity is predominant in the first phase, whereas the parasympathetic activity is dominant in the second and third phases of hemorrhagic shock. There is an inverse relationship between the level of VLF and lung injury in vagotomized animals subjected to hemorrhagic shock.

A Bezoar Causing Bowel Obstruction After Roux-en-Y Gastric Bypass: A Case Report

Abstract- We aimed to present a patient with phytobezoar causing small bowel obstruction after Roux-en-Y gastric bypass. Thirty-year-old woman with a history of prior Roux-en-Y gastric bypass due to morbid obesity three years ago presented with colicky abdominal pain, distention, nausea, vomiting, and obstipation. Initial abdominal X-ray showed various distended small bowel loops with air-fluid levels. The patient was taken to operation room for laparoscopic exploration, and a phytobezoar was found in distal jejunum. The bezoar was fragmented and flushed through cecum. The patient tolerated the surgery and her symptoms relieved without complication. Moreover, she received dietary consultation in order to prevent future recurrences. Small bowel obstruction in a patient with prior abdominal surgery is mainly caused due to adhesions, stenosis of anastomosis and hernias. An uncommon cause for obstruction is bezoar formation. The majority of patients with bezoars have a history of gastric surgery. Diagnostic imaging is not always helpful, and surgical exploration is sometimes required for diagnosis. Treatment is mainly surgical, but conservative medical treatment is also reported to be helpful. Apart from removal of bezoar, a dietary consultation is required to avoid eating habits leading to bezoar formation. Bariatric surgery is becoming more common; thus its complications are becoming more common as well. Majority of patients with bezoars have a prior history of gastric surgery. Therefore it is important to maintain a high level of suspicion for timely diagnosis of bezoars in patients with prior history of bariatric surgery, especially Roux-en-Y gastric bypass.

Mitigation of Radiation-Induced Lung Pneumonitis and Fibrosis Using Metformin and Melatonin: A Histopathological Study

Background and objectives: Pneumonitis and fibrosis are the most common consequences of lung exposure to a high dose of ionizing radiation during an accidental radiological or nuclear event, and may lead to death, after some months to years. So far, some anti-inflammatory and antioxidant agents have been used for mitigation of lung injury. In the present study, we aimed to detect possible mitigatory effects of melatonin and metformin on radiation-induced pneumonitis and lung fibrosis. Materials and methods: 40 male mice were divided into 4 groups (10 mice in each). For control group, mice did not receive radiation or drugs. In group 2, mice were irradiated to chest area with 18 Gy gamma rays. In groups 3 and 4, mice were first irradiated similar to group 2. After 24 h, treatment with melatonin as well as metformin began. Mice were sacrificed after 100 days for determination of mitigation of lung pneumonitis and fibrosis by melatonin or metformin. Results: Results showed that both melatonin and metformin are able to mitigate pneumonitis and fibrosis markers such as infiltration of inflammatory cells, edema, vascular and alveolar thickening, as well as collagen deposition. Conclusion: Melatonin and metformin may have some interesting properties for mitigation of radiation pneumonitis and fibrosis after an accidental radiation event.

A paper-based length of stain analytical device for naked eye (readout-free) detection of cystic fibrosis

The test of sweat chloride is routinely performed as a worldwide newborn screening (NBS) to the diagnosis of cystic fibrosis (CF) in infants. However, the available methods for measurement of chloride in sweat suffer from such limitations as either low selectivity and/or requiring relatively large sample size. In this work, we have designed an analytical ruler that can measure chloride ion in sweat and hence can be used for the diagnosis of cystic fibrosis. This micro-pad (μ-PAD) device is fabricated by making hydrophilic micro-channel on a filter paper impregnated with silver dichromate. After addition of chloride ion-containing sweat sample, it moves through the channel, leading to the formation of an AgCl sediment, which deposits as a white color stain, the length of which in the channel being proportional to the amount of chloride ion in sweat. A well-defined linear relation was observed between the length of white color stain and the concentration of chloride ion in the sample solutions with a relative standard deviation of 3.6% (n = 3) for an artificial sweat sample containing 100 mM chloride ion. The possible interfering effects of several different cations and anions on the detection of chloride ion were investigated and the results well-confirmed the selectivity of the proposed method. With the use of only 2.0 μL of the sample solution, the μPAD was able to measure the chloride content of sweat over a concentration range of 20.0-100.0 mM, which covers both the healthy range (˂ 40 mM) and the risky range (˃60 mM) of chloride ion. Analysis of chloride content of sweat samples by the μPAD agreed well with those obtained by a standard electrochemical method (with relative errors of lower than 10%).

Triggering apoptosis in cancer cells with an analogue of cribrostatin 6 that elevates intracellular ROS

Elevation of reactive oxygen species (ROS) is both a consequence and driver of the upregulated metabolism and proliferation of transformed cells. The resulting increase in oxidative stress is postulated to saturate the cellular antioxidant machinery, leaving cancer cells susceptible to agents that further elevate their intracellular oxidative stress. Several small molecules, including the marine natural product cribrostatin 6, have been demonstrated to trigger apoptosis in cancer cells by increasing intracellular ROS. Here, we report the modular synthesis of a series of cribrostatin 6 derivatives, and assessment of their activity in a number of cell lines. We establish that placing a phenyl ring on carbon 8 of cribrostatin 6 leads to increased potency, and observe a window of selectivity towards cancer cells. The mechanism of activity of this more potent analogue is assessed and demonstrated to induce apoptosis in cancer cells by increasing ROS. Our results demonstrate the potential for targeting tumors with molecules that enhance intracellular oxidative stress.

The half Heusler system Ti1+xFe1.33−xSb–TiCoSb with Sb/Sn substitution: phase relations, crystal structures and thermoelectric properties

Phase equilibria for Heusler Phase Ti_1+xFe_1.33−xSb at 800 °C and calculated isosurfaces (ϒ = 0.42) of the electron localization function in TiFe_1.25Sb.

KRAS Codon 12 and 13 Mutations in Gastric Cancer in the Northeast Iran

BACKGROUND & OBJECTIVE

KRAS mutations are reported in many types of cancers including pancreas, lung, colon, breast,and gastric (GC). High frequency of KRAS mutation is observed in the pancreas,colon, and lung cancers; they commonly arise in codon 12 and 13 of exon 2. Due to the lack of information about the frequency of KRAS mutations in the Northeast of Iran, the currentstudy aimed at evaluating KRAS frequency in cases with GC in this region.

METHODS

A total of120 formalin-fixed, paraffin-embedded blocks of patients with GC were assessed. The assays to detect KRAS in codon 12 and13 were obtained through the peptide nucleic acid (PNA)-clamp.

RESULTS

Totally 87 male and 33 female patients were analyzed in the current study. The mean age of the subjects was 55years.The most common tumoral fragment was located on the body with 48 cases (40%) and the less frequent was related to fondues with six cases (5%).Of the 120 GC samples, 16(13.3%) caseshad codon 12 KRAS mutation, and 16.7% had codon 13 mutations. There were no significant relationships between gender,age, and KRAS mutations in the studied specimens.

CONCLUSION

In conclusion, the overall frequency of KRAS codon 12 and 13 mutations in GC was 30% in the current study population.Frequency of KRAS codon 12 and 13 mutations hadsignificant correlation with tumors location. Different pathogenic mechanismsare suggested for GC according to tumor location. The current study resultsmay be an important diagnostic tool for physicians managing atrophic gastritis.

Effect of bariatric surgery on adiposity and metabolic profiles: A prospective cohort study in Middle-Eastern patients

AIM

To investigate changes in adiposity and cardio-metabolic risk profile following Roux-en-Y gastric bypass in patients of Middle Eastern ethnicity with severe obesity.

METHODS

This prospective cohort study involved 92 patients who met the indications of bariatric surgery. Post-procedure markers of obesity and cardiometabolic profile were monitored regularly for a year.

RESULTS

Mean body mass index decreased by 29.5% from 41.9 to 29.5 kg/m2 between baseline and 12-mo follow-up, while mean fat mass decreased by 45.9% from 64.2 kg to 34.7 kg. An improvement was also observed in the gluco-metabolic profile with both fasting glucose and HbA1c substantially decreasing (P < 0.001).

CONCLUSION

The present study shows the short to medium term (1 year) health benefits of bariatric surgery for patients of Middle Eastern ethnicity.

The efficacy of the ketogenic diet in infants and young children with refractory epilepsies using a formula-based powder

To evaluate the efficacy, safety, and tolerability of a classic 4:1 ketogenic diet using a formula-based powder in infants and children with refractory seizures who are reluctant to eat homemade foods. We conducted an open label trial and administered a ketogenic diet using formula-based power (Ketocal^®). Twenty-seven infants and children aged between 12 months and 5 years were enrolled who had refractory seizures and were reluctant to eat homemade foods. Of 27 children, 5 were lost to follow-up and 22 were remained at the end of the study. After 4 months, the median frequency of seizures per week was reduced >50% in 68.2% of patients, while 9/22 children (40.9%) showed a 50-90% reduction in seizure frequency per week, and 6/22 children (27.3%) showed more than 90% reduction in seizure frequency per week. Over the study course, 6/22 (27%) children who continued to receive the diet developed constipation, one child developed gastroesophageal reflux, and one child developed hypercholesterolemia. None of these children discontinued the diet because of the complications. Thirteen children and their parents (59%) reported that the diet was palatable and tolerable enough. The ketogenic diet using a formula-based powder (Ketocal^®) is effective, safe, and tolerable in infants and children with refractory seizures who are reluctant to eat homemade foods according to the rules of the ketogenic diet.

A Novel Approach to Minimally Invasive Management of Sigmoid Volvulus

Resection is the most common treatment choice for sigmoid volvulus, a common complication in our region. A new minimally invasive technique for sigmoid resection with local anesthesia was done in this study. This method is invented to avoid general on regional anesthesia in high-risk patients. Nineteen patients were evaluated and then 14 were enrolled in this study. Sigmoidectomy with a left lower quadrant incision was performed and demographic data, the length of hospital stay, complications and procedure time were recorded. The mean age of participants was 65.68, and the male to female ratio was 1:2.7. The mean duration of the operation was 91.42 min. Complications include one case each of wound hematoma and wound infection. The intraoperative pain score was 1.2/10 and postoperative pain score was 2.35/10. The mean hospital staying was 8.3 days. By meticulous patient selection, sigmoidectomy under local anesthesia for sigmoid volvulus could be a surgeons' armamentarium in special situations.

Post-translational control of protein function with light using a LOV-intein fusion protein

Methods for the post-translational control of protein function with light hold much value as tools in cell biology. To this end, we report a fusion protein that consists of DnaE split-inteins, flanking the light sensitive LOV2 domain of Avena sativa. The resulting chimera combines the activities of these two unrelated proteins to enable controlled formation of a functional protein via upregulation of intein splicing with blue light in bacterial and human cells.

Difficulties in the diagnosis and management of alveolar hydatid disease: A case series

BACKGROUND

Alveolar echinococcosis (AE) is a chronic, rare and sometimes lethal parasitic infection in humans, caused by the larval stage of the fox tapeworm Echinococcus multilocularis. This study aimed to investigate the clinical aspects and treatment outcomes of patients with alveolar hydatid disease.

METHODS

The medical records of patients with alveolar echinococcosis admitted between 1997 and 2012 were reviewed. Diagnosis was confirmed by physical examination, ultrasonography and CT scanning and MRI. Various treatment techniques were used such as complete liver resection in seven (38.89%) patients, biliary bypass in two (11.11%) patients, laparotomy and tumor biopsy in eight (44.44%) patients and long term medical treatment in one (5.56%) patient. After discharge, all patients were followed to determine the effect of treatment, complications, recurrences and survival.

RESULTS

A total of 18 patients with mean age of 46.11±15.14 years (range 23-74 years) were studied. The disease was more prevalent in women than men (78.9% vs 4, 21.1%, P=0.021). Fourteen (77.78%) patients live in Chenaran, a town located in Khorasan, Iran). Death occurred in (22.22%) patients after an average period of 45.70±7.50 months after disease onset. 14 remaining patients survived after a mean follow-up duration of 54.60±29.17 months.

CONCLUSION

Diagnosis of alveolar echinococcosis should be considered in endemic area. Early diagnosis and treatment is associated with excellent outcome.

Radioprotective effect of melatonin on radiation-induced lung injury and lipid peroxidation in rats

Objective

Free radicals generated by ionizing radiation attack various cellular components such as lipids. The lung is a very radiosensitive organ and its damage is a doselimiting factor in radiotherapy treatments. Melatonin (MLT), the major product of the pineal gland acts as a radioprotective agent. This study aims to investigate the radioprotective effects of MLT on malondialdehyde (MDA) levels and histopathological changes in irradiated lungs.

Materials and Methods

In this experimental study, a total of 62 rats were divided into five groups. Group 1 received no MLT and radiation (unT), group 2 received oral MLT (oM), group 3 received oral MLT and their thoracic areas were irradiated with 18 Gy (oMR), group 4 received MLT by intraperitoneal (i.p.) injection and their thoracic areas were irradiated with 18 Gy (ipM-R), group 5 received only 18 Gy radiation in the thoracic area (R). Following radiotherapy, half of the animals in each group were sacrificed at 48 hours for evaluation of lipid peroxidation and early phase lung injuries. Other animals were sacrificed in the eighth week of the experiment for evaluation of the presence of late phase radiation induced lung injuries.

Results

Pre-treatment of rats with either i.p injection (p<0.05) and oral administration of MLT (p<0.001) significantly reduced MDA levels in red blood cell (RBC) samples compared to the R group. Furthermore, i.p. injection of MLT decreased MDA levels in plasma and tissue (p<0.05). In the early phase of lung injury, both administration of MLT significantly increased lymphocyte (p<0.05) and macrophage frequency (p<0.001). MLT reduced the lung injury index in the lungs compared to the R group (p<0.05).

Conclusion

The result of this study confirms the radioprotective effect of MLT on lipid peroxidation, and in both early and late phases of radiation induced lung injuries in an animal model.

Probing the epigenetic regulation of HIF-1α transcription in developing tissue

HIF-1-mediated hypoxia signalling in embryonic tissue is probed by assessing the methylation status of the HIF-1α and EPO HRE promoters using bisulfite sequencing.

Can methylene blue dye be used as an alternative to patent blue dye to find the sentinel lymph node in breast cancer surgery?

BACKGROUND

Sentinel lymph node biopsy (SLNB) is standard care to evaluate axillary involvement in early breast cancer. It has fewer complications than complete lymph node dissection; however, using blue dye in SLNB is controversial. We have evaluated the detection rate and local complications associated with methylene blue dye (MBD) used in SLNB in early breast cancer patients and compared these results to patent blue dye (PBD).

MATERIALS AND METHODS

In a cohort prospective study, 312 patients with early breast cancer without axillary lymph node involvement were divided into two groups according to dye type. All of the patients received radiotracer and one type of blue dye. We filled out a checklist for the patients that contained demographic data, size of tumor, stage, detection of sentinel lymph node, and complications and then analyzed the data.

RESULTS

Demographic and histopathologic characteristics were not significantly different in both groups. Mean (standard deviation [SD]) tumor size in all patients was 2.4 (0.8) cm. Detection rate in the MBD group was 77.5% with dye alone and 94.2% with dye and radioisotope; and in the PBD group it was 80.1% and 92.9% respectively (P > 0.05). We had blue discoloration of the skin in 23.7% in the PBD and 14.1% in the MBD group (P < 0.05) local inflammation was detected in one patient in the PBD and five in the MBD group (P < 0.05). Skin necrosis and systemic complications were not observed.

CONCLUSION

Methylene blue has an acceptable detection rate, which may be a good alternative in SLNB. Complication such as blue discoloration of the skin was also lower with MBD.

Management of sigmoid volvulus: options and prognosis

OBJECTIVE

To describe the management of sigmoid volvulus with reference to the type of surgical procedures performed and to determine the prognosis of sigmoid volvulus.

STUDY DESIGN

A case series.

PLACE AND DURATION OF STUDY

Ghaem Hospital of Mashhad, University of Medical Sciences, Mashhad, Iran, from 1996 to 2008.

METHODOLOGY

A total of 944 cases of colon obstruction were reviewed. Demographic, laboratory and treatment results, mortality and complications were recorded. The data was analyzed using descriptive statistics as frequency and percentage for the qualitative variables and mean and standard deviation values for the quantitative variables. Also chisquare and Fisher's exact test were used for the association between the qualitative variables. SPSS statistical software (version 18) was used for the data analysis.

RESULTS

In all patients except those with symptoms or signs of gangrenous bowel, a long rectal tube was inserted via the rectosigmoidoscope which was successful in 80 (36.87%) cases. Rectosigmoidoscopic detorsion was unsuccessful in 137 (63.13%) patients, who underwent an emergent laparotomy. The surgical procedures performed in these cases were resection and primary anastomosis in 40 (29.1%), Mikulicz procedure in 9 (6.6%), laparotomy detorsion in 37 (27.01%), Hartmann procedure in 47 (34.3%), mesosigmoidoplasty in 3 (2.19%) patients and total colectomy in one (0.73%) case. The overall mortality was 9.8% (22) patients.

CONCLUSION

In sigmoid volvulus, the most important determinant of patient outcome is bowel viability. The initial treatment of sigmoid colon volvulus is sigmoidoscopy with rectal tube placement.

A survey of resident physicians' knowledge concerning transfusion medicine in Shiraz, Iran

OBJECTIVE

The knowledge of physicians concerning blood transfusion has a significant impact on the optimal use of blood and blood products. The aim was to survey their knowledge regarding this area and identify whether additional training is required.

MATERIAL AND METHODS

This cross-sectional study was conducted on all 1(st) year resident physicians at Shiraz University of Medical Sciences, Iran in 2011. The questionnaire solicited information on demographic variables, knowledge regarding transfusion medicine, education and experience regarding blood transfusion.

RESULTS

The mean total knowledge score regarding transfusion medicine was 15.44 ± 3.3 (7-25) out of 29. Only about one-fourth (27.4%) replied correctly to over 60% of questions. The mean score of knowledge was higher among residents who stated that they received special training regarding blood transfusion in their medical courses (P < 0.01). Seventy-five percent of residents believed that they had received insufficient education and 97.8% believed that they need additional training.

CONCLUSION

The results reflect the uncertainties among resident physicians regarding blood transfusion. It has been suggested that a special transfusion medicine educational program should be added to the medical education curriculum.

Aberrant expression of DPPA2 and HIWI genes in colorectal cancer and their impacts on poor prognosis

Cancer cells have countless behaviors of pluripotent embryonic stem cells and germ line cells, such as unlimited proliferation, self-renewal, and migration. Expression of specific germ line and embryonic genes in tumor cells may be associated with indefinite growth and invasiveness of such cells. Developmental pluripotency factor 2 (DPPA2) and HIWI are two important developmental genes which are involved in embryonic and germ line stem cell properties. Deciphering the role of these genes seems to be necessary for understanding cancer initiation and progression. Tumoral and normal tissues from 46 colorectal cancer (CRC) patients were subjected to gene expression analysis using quantitative real-time reverse transcription-polymerase chain reaction, prior to any therapeutic intervention. Overexpression of DPPA2 and HIWI was detected in 26.1 and 34.8 % of specimens, respectively. Significant correlation between DPPA2 overexpression and lymph node metastasis of the tumor cells (P=0.049) was seen in the samples with advanced stages (III/IV) of the tumor development. HIWI mRNA expression was significantly associated to the depth of tumor invasion (P=0.020) and the stage of tumorigenesis progression (P=0.030). In samples with overexpression of at least one gene, DPPA2 mRNA expression was significantly correlated to the stage of tumor (P=0.017). In the same samples, a significant correlation was observed between mRNA expression of HIWI and the stage of tumor cells (P=0.034). These results documented the important role of HIWI and DPPA2 in tumorigenesis and also in lymph node metastasis of tumor cells. Further evaluation is required to uncover the detailed role of HIWI and DPPA2 and their interactions in tumorigenesis of CRC.

HIF-1 promotes the expression of its α-subunit via an epigenetically regulated transactivation loop

A HIF-1 protein–protein interaction inhibitor is used to establish the presence of a HIF-1α transactivation loop in hypoxia.

Esophageal diverticula: Analysis of 25 cases

BACKGROUND

esophageal diverticula are classified as 2 types: true diverticula and pseudodiverticula. These disorders result in clinical manifestations such as dysphagia and esophageal reflux. In this study, we evaluated the results of surgical treatment for diverticula.

METHODS

all patients suffering from symptomatic esophageal diverticulum, who underwent surgical treatment in Ghaem Hospital from 2000 to 2012 and were followed up for at least for one year, were included in the study. Age, sex, clinical manifestations, location, surgical approach, and mortality were evaluated. There were 25 patients (15 men and 10 women) with a mean age of 41 ± 8.3 years.

RESULTS

the most common site of involvement was inferior (epiphrenic diverticulum). Barium swallow was diagnostic. After surgical treatment, complications occurred in 4 (16%) patients, comprising anastomosis site leakage, hoarseness, atelectasis, and wound infection; all were treated medically. There was no postoperative mortality. All patients experienced an improvement in symptoms during one year of follow-up.

CONCLUSION

due to the good results and minimal complications postoperatively, surgical treatment is recommended for patients with symptomatic esophageal diverticulum.

Acute disseminated encephalomyelitis mimicking acute meningoencephalitis

Acute disseminated encephalomyelitis is an inflammatory demyelinating disease of the central nervous system that usually occurs following an antecedent infection or vaccination. Children and young adults are predominantly affected, but it has low incidence in children younger than 3 years. The disease manifests with a wide range of neurological abnormalities and a variable combination of fever, headache, meningism, convulsion and cranial nerve palsies, and there are no pathognomonic clinical or laboratory findings. So, establishment of definitive diagnosis is challenging in infants. This challenge may result in delayed diagnosis and consequently delayed treatment of acute disseminated encephalomyelitis, which may cause permanent neurological disability. Herein, we report an infant with acute disseminated encephalomyelitis, who mimicked the symptoms of meningoencephalitis and the correct diagnosis and treatment were delayed till the development of a severe phase of the disease.

Hepatitis C Virus Infection in HIV Positive Attendees of Shiraz Behavioral Diseases Consultation Center in Southern Iran

OBJECTIVE

To determine the prevalence of HCV co-infection and its correlation with demographic and risk factors among human immunodeficiency virus (HIV)-infected individuals attending Shiraz behavioral diseases consultation (SBDC) Center in southern Iran.

MATERIALS AND METHODS

In a cross-sectional study, 226 consecutive HIV-positive patients who referred to SBDC Center from April 2006 to March 2007 were interviewed face-to-face to record demographic data and risk factors of HIV transmission. A 10ml sample of venous blood was drawn from every subject and tested for HCV-antibodies by third generation enzyme linked immunosorbant (ELISA) and recombinant immunoblot assays (RIBA). All samples were also analyzed by qualitative reverse transcriptase polymerase chain reaction (RT-PCR) for detection of HCV-RNA.

RESULTS

The study population consisted of 214 men (94.7%) and 12 women (5.3%) with a mean age of 35.6 ± 7.9 years. The most prevalent risk factor was imprisonment (88.9%) followed by injecting drug use (79.2%). The prevalence of HCV infection was 88.5% by ELISA and 86.7% by RIBA, while HCV viremia was detected in 26.1% of the patients. HCV-antibody positivity was significantly associated with gender, age, marital status, occupation, injecting drug use, and history of imprisonment. It was inversely related to having an infected or high risk sexual partner. In the logistic regression model, the predictors of HCV-positivity were injecting drug use (OR = 24.9, P = 0.004) and imprisonment (OR = 21.4, P < 0.001).

CONCLUSIONS

Prevalence of HCV infection among HIV-positive individuals in our region is very high and there is a need for stricter preventive actions against transmission of HCV among this group of patients.

The role of thoracoscopic debridement in the treatment of parapneumonic empyema

AIM

To evaluate the efficacy of early video-assisted thoracoscopic debridement in patients with the fibropurulent phase of parapneumonic empyema.

PATIENTS AND METHODS

40 patients with parapneumonic empyema resistant to 2 weeks of antibiotic therapy, were randomly divided into 2 groups. In group 1 (20 patients), antibiotic therapy and irrigation was continued, and in group 2 (20 patients), video-assisted thoracoscopic debridement was performed. The 2 groups were compared in terms of therapeutic results.

RESULTS

The male/female ratio was 29/11. Group 1 included 16 men and 4 women with a mean age of 54 years, and mean hospital stay was 41 days. Group 2 consisted of 14 men and 6 women with a mean age of 51 years, and mean hospital stay was 23 days. Considering the therapeutic results, 12 patients in group 1 were cured by antibiotic therapy and irrigation, whereas 8 required decortication and pleurectomy with thoracotomy. In group 2, 18 patients were cured by video-assisted thoracoscopic debridement, and 2 underwent thoracotomy and decortication due to intraoperative bleeding. A significant difference in therapeutic results was noted between the groups (p = 0.028).

CONCLUSION

Video-assisted thoracoscopic debridement provides a high success rate and less invasive treatment for the early stages of empyema.

Evaluation of methylation of MGMT (O⁶-methylguanine-DNA methyltransferase) gene promoter in sporadic colorectal cancer

The DNA repair gene O⁶-methylguanine-DNA methyltransferase (MGMT) is frequently methylated in colorectal cancer (CRC). The aim of this study was to demonstrate that MGMT methylation may be one of the candidate mediators of field cancerization in the colon mucosa. Therefore, quantitative methylation-specific polymerase chain reaction was performed on tumor itself and additional samples of 5 and 10 cm away from the tumor in 40 CRC patients. Moreover, colon mucosa was examined from 30 cases with no evidence of cancer as a control. MGMT promoter methylation was present in 27.5% of colorectal tumor specimens. Tumors that showed MGMT promoter methylation had substantial MGMT promoter methylation in their normal adjacent mucosa. The methylation was also observed in 36.36% (4/11) of normal samples with MGMT promoter methylation in the adjacent tumors, in 20.79% (6/29) of samples without MGMT methylation in the adjacent tumors, and in 6.66% (2/30) of control samples (p<0.006 and p<0.001 respectively). Finally, the mean of MGMT methylation levels was significantly higher in the cancerous group than in the control group (6.25±1.702 vs. 0.086±0.036, p<0.001). Some CRCs arise from a field defect defined by epigenetic inactivation of MGMT. Detection of such abnormality may ultimately be useful in risk assessment for CRCs.

The role of VATS in the staging of non small cell lung cancer

INTRODUCTION

Since determining of prognosis and treatment method is related to accurate evaluation of TNM staging of non small cell lung cancer (NSCLC), we aimed to evaluate the role of Video-assisted thoracic surgery (VATS) in staging of NSCLC.

MATERIALS AND METHODS

This study was performed on 40 patients with NSCLC who had undergone preoperative staging and were candidate for curative surgery between 2008-2010. They underwent VATS immediately before the surgery. After performing VATS, the patients underwent thoracotomy by posterolateral incision unless any criteria of inoperability were present. Diagnostic accuracy of VATS for confirmation or modification of preoperative staging was evaluated.

RESULTS

M/F ratio was 21/19. Mean age of the patients was 57.2 ± 16.64 yrs. The most common symptom was coughing in 90% of patients. 72.5% of the patients had endobronchial mass and only for 27.5% tissue sample was obtained by transthoracic needle biopsy (TTNB) method. After performing VATS, 6 patients were excluded from surgery (3 cases (7.5%) due to seeding plural metastasis, 2 cases (5%) due to N2 involvement and one case (2.5%) due to satellite lesion in other lobes). Other 34 patients underwent surgery. Surgical resection was performed successfully in 31 cases (77.5%), but in 3 cases (7.5%) due to adhesion to hillum of the lung tumor was not resectable. According to the above results, VATS diagnosing accuracy was 92.5%.

CONCLUSION

VATS can help to determine TNM staging and prevent unnecessary thoracotomy in some patients and we recommend this method for accurate staging of NSCLC.

Role of SALL4 in the progression and metastasis of colorectal cancer

Background

Human cancer cells resemble stem cells in expression signatures leading them to share some features, most notably, self-renewal. A complex network of transcription factors and signaling molecules are required for continuance of this trait. SALL4 is a zinc finger transcriptional activator crucial for maintenance of self-renewal in stem cells; however, its expression level has not yet been elucidated in colorectal tumor cells. To determine this level and probable clinicopathological consequences, its expression was analyzed.

Methods

SALL4 expression in fresh tumoral and distant tumor-free tissues from 46 colorectal samples was compared by real-time polymerase chain reaction (PCR).

Results

Greater than a two-fold increase in SALL4 expression was detected in 87% of tumors vs. normal related tissues. SALL4 expression was significantly correlated with tumor cell metastasis to lymph nodes, especially in moderately-differentiated tumor samples (P < 0.05). Furthermore, higher levels of SALL4 mRNA expression were significantly associated with younger than older patients with tumor cells in stages I and II (P < 0.05).

Conclusions

These results indicate a relationship between SALL4 expression and tumor cell metastasis to lymph nodes and consequent advancement of tumors to advanced stages III and IV. Along with the promising evidence of its role in self-renewal in various cancers, SALL4 may have a role in progression, development and maintenance of colorectal cancers.

Evaluation of curcumin effects on post-operative peritoneal adhesion in rats

OBJECTIVES

The purpose of this study holds, for the first time, an evaluation of the intraperitoneal curcumin lavage on the development of post-operative intra-abdominal adhesions.

MATERIALS AND METHODS

Thirty male Wistar rats were randomized into five groups. The rats were administered anesthesia and underwent surgery in order to create intra-abdominal adhesions. Before the abdomen was closed, five lavage solutions of normal saline (control group), curcumin 1, 3, and 5% and hydrocortisone 1% were used for 1 min. After five days, the rats underwent laparatomy. Based on a histopathology evaluation and serum levels of hs-CRP, TNFα and Isoprostane, peritoneal adhesion severity were compared in different groups.

RESULTS

The groups that received curcumin 3% and 5% showed a significant decrease in TNFα, hs-CRP and Isoprostane serum concentrations compared to the normal saline group, however, these differences were not significant, between the other groups. The intensity of adhesions in the different groups of curcumin 1, 3 and 5% concentrations and hydrocortisone 1% were compared to the normal saline control group and no significant statistical difference was recorded.

CONCLUSION

Curcumin was not effective in post-operative peritoneal adhesion; however, further studies on curcumin lavage in higher concentrations are recommended.

Comparison of pre-operative lymphoscintigraphy with inter-operative gamma probe and dye technique regarding the number of detected sentinel lymph nodes

Sentinel lymph node (SLN) identification by lymphoscintigraphy (LS) and biopsy are the standard method for axillary lymph node staging in low stage breast cancer patients. Many previous studies did not compare the number of SLN on LS with SLN detected during surgery. We aimed to study the accuracy of pre-operative LS for the prediction of the number of SLN detected by surgical gamma probe and the dye technique during surgery. Sixty patients were included in our study. SLN biopsy was performed using the combined radioactive and blue dye methods. Patients without previous excisional biopsy of the tumor (45 patients) received periareolar intra-dermal injections of 17.5MBq/0.2mL technetium-99m-antimony sulfide colloid ((99m)Tc ASC). The remainder of the patients, with the history of excisional biopsy of the tumor (15 patients); received two intra-dermal injections of 17.5MBq/0.2mL (99m)Tc-ASC in both ends of the surgical incision. All injections were done 2-4 h before surgery and gentle massage was applied to the injection site. Results showed that the number of SLN was correctly detected by LS in 58 patients. Eighty SLN were totally detected during surgery. All these SLN were radioactive and could be identified by surgical gamma probe. No SLN was detected only by the blue dye. Of the 80 detected SLN, 60 (75%) were both radioactive and colored. Pre-operative LS correctly predicted the number of harvested SLN during surgery in 77.5% of the patients. Only 78.7% (63/80) of the total harvested SLN were detected by pre-operative LS. We conclude that pre- operative LS identifies 78.7% and the blue dye technique can identify 75% of the SLN found by the gamma probe during surgery. The pre-operative LS technique can correctly identify the number of SLN in 77.5% of the patients.

Eye movements selective for spatial frequency and orientation during active visual search

Visual search can simply be defined as the task of looking for objects of interest in cluttered visual environments. Typically, the human visual system succeeds at this by making a series of rapid eye movements called saccades, interleaved by discrete fixations. However, very little is known on how the brain programs saccades and selects fixation loci in such naturalistic tasks. In the current study, we use a technique developed in our laboratory based on reverse-correlation(1) and stimuli that emulate the natural visual environment to examine observers' strategies when seeking low-contrast targets of various spatial frequency and orientation characteristics. We present four major findings. First, we provide strong evidence of visual guidance in saccadic targeting characterized by saccadic selectivity for spatial frequencies and orientations close to that of the search target. Second, we show that observers exhibit inaccuracies and biases in their estimates of target features. Third, a complementarity effect is generally observed: the absence of certain frequency components in distracters affects whether they are fixated or mistakenly selected as the target. Finally, an unusual phenomenon is observed whereby distracters containing close-to-vertical structures are fixated in searches for nonvertically oriented targets. Our results provide evidence for the involvement of band-pass mechanisms along feature dimensions (spatial frequency and orientation) during visual search.

Flow-injection analysis of nitrate by reduction to nitrite and gas-phase molecular absorption spectrometry

Two flow-injection manifolds have been investigated for the determination of nitrate. These manifolds are based on the reduction of nitrate to nitrite and determination of nitrite by gas-phase molecular absorption spectrophotometry. Nitrate sample solution (300 microL) which is injected to the flow line, is reduced to nitrite by reaction with hydrazine or passage through the on-line copperized cadmium (Cd-Cu) reduction column. The nitrite produced reacts with a stream of hydrochloric acid and the evolved gases are purged into the stream of O2 carrier gas. The gaseous phase is separated from the liquid phase using a gas-liquid separator and then swept into a flow-through cell which has been positioned in the cell compartment of an UV-visible spectrophotometer. The absorbance of the gaseous phase is measured at 204.7 nm. A linear relationship was obtained between the intensity of absorption signals and concentration of nitrate when Cd-Cu reduction method was used, but a logarithmic relationship was obtained when the hydrazine reduction method was used. By use of the Cd-Cu reduction method, up to 330 microg of nitrate was determined. The limit of detection was 2.97 microg nitrate and the relative standard deviations for the determination of 12.0, 30.0 and 150 microg nitrate were 3.32, 3.87 and 3.6%, respectively. Maximum sampling rate was approximately 30 samples per hour. The Cd-Cu reduction method was applied to the determination of nitrate and the simultaneous determination of nitrate and nitrite in meat products, vegetables, urine, and a water sample.