Evaluation of the immune response in BALB/c mice induced by a novel DNA vaccine expressing GRA14 against Toxoplasma gondii.

Toxoplasma gondii can cause severe and even fatal disease in human beings and animals. Effective vaccines may contribute to control toxoplasmosis. GRA14, a novel secreted dense granule protein of T. gondii, has been proposed as a vaccine candidate due to its intervacuolar transport and unique topology in the parasitophorous vacuole membrane. In this study, we constructed a DNA vaccine encoding GRA14 of T. gondii. BALB/c mice were immunized intramuscularly three times at 2 week intervals and challenged with T. gondii RH strain 5 weeks later. The immune responses were evaluated using lymphocyte proliferation assay, cytokine and antibody measurements. In addition, the survival times and parasite load of mice challenged with the virulent T. gondii RH strain were evaluated. The results showed that the mice immunized with pcGRA14 induced both enhanced specific humoral and Th1 cellular immune responses, and also mice immunized with the pcGRA14 showed an increased survival time and decreased parasite load compared with control groups (P<.05). The results indicated, for the first time, that the GRA14 is a potential DNA vaccine against toxoplasmosis.

Prevalence of chronic pulmonary aspergillosis in patients with tuberculosis from Iran.

In patients with preexisting lung disease, especially a cavity, Aspergillus can infect the surface of the cavity, causing chronic cavitary pulmonary aspergillosis (CCPA), and may form an aspergilloma, collectively called chronic pulmonary aspergillosis (CPA). In the present study, we assessed tuberculosis (TB) patients for CPA based on culture and serological methods. During a period of 1 year (from March 2013 to March 2014), we studied 124 patients with TB (94 with current TB and 30 with previous TB) at Masih Daneshvari Hospital in Tehran, Iran. Sputum specimens were analyzed by direct microscopic examination (DME) and fungal culture. The clinical and radiological features of all patients were recorded, to categorize the patients into CCPA and aspergilloma. All patients were screened for serum-specific IgG against A. fumigatus, by enzyme-linked immunosorbent assay (ELISA). Out of 124 patients with TB (66 male, age range: 10-91 years), 48 patients (38.7 %) exhibited residual cavities. Eighteen (14.5 %) patients had cavities with pleural thickening. A round-shaped mass lesion was detected in six patients (6.8 %). DME was positive in ten patients for septate fungal hyphae. A. fumigatus was grown from 14 samples. Fifty-five (44.3 %) cases were positive for serum-specific IgG against A. fumigatus. Of 124 patients with TB, 3 (2.4 %) met criteria for aspergilloma and 14 (11.3 %) for CCPA. CPA is a common clinical presentation in individuals with healed TB in Iran, as reported by previous studies from other countries.

Changes in serum levels of brain derived neurotrophic factor and nerve growth factor-beta in schizophrenic patients before and after treatment.

Schizophrenia is one of the most debilitating diseases among psychiatric disorders. Recent studies suggest the existence of effective immunological changes in the pathophysiology of this disease. The purpose of the current study was to determine the changes in serum levels of Brain Derived Neurotrophic Factor (BDNF) and Nerve Growth Factor-beta (NGF) in schizophrenic patients before treatment and 40 days after treatment. In this case-control study, serum levels of BDNF and NGF were measured by ELISA in 26 patients with schizophrenia and 26 healthy controls. All patients were treated with clozapine or risperidone for 40 days. A positive and negative syndrome scale (PANSS) questionnaire has been used to recognize the severity of the disease and to assess the response to treatment. Neurotrophin concentrations were compared before and after the treatment and with control groups using paired t-test and ANOVA test. BDNF and NGF levels in the case group were more than levels after treatment, but these differences were significant only for NGF. Concentrations in both neurotrophins were higher than the control group. The statistically significant difference was observed between changes in the NGF levels in the case and the control group, while no significant difference was seen in changes of BDNF. The main conclusion to be drawn from this study was that the increase in BDNF and particularly NGF may have an important role in causing schizophrenia. And possibly drugs clozapine and risperidone help to treat the disease by reducing the concentration of Neurotrophins.

Site specific nematode management-development and success in cotton production in the United States.

Variability in edaphic factors such as clay content, organic matter, and nutrient availability within individual fields is a major obstacle confronting cotton producers. Adaptation of geospatial technologies such global positioning systems (GPS), yield monitors, autosteering, and the automated on-and-off technology required for site-specific nematicide application has provided growers with additional tools for managing nematodes. Multiple trials in several states were conducted to evaluate this technology in cotton. In a field infested with Meloidogyne spp., both shallow (0 to 0.3 m) and deep (0 to 0.91 m) apparent electrical conductivity (ECa) readings were highly correlated with sand content. Populations of Meloidogyne spp. were present when shallow and deep EC values were less than 30 and 90 mS/m, respectively. Across three years of trials in production fields in which verification strips (adjacent nematicide treated and untreated rows across all soil zones) were established to evaluate crop response to nematicide application, deep EC values from 27.4-m wide transects of verification strips were more predictive of yield response to application of 1,3-dichloropropene than were shallow EC values in one location and both ECa values equally effective at predicting responses at the second location. In 2006, yields from entire verification strips across three soil zones in four production fields showed that nematicide response was greatest in areas with the lowest EC values indicating highest content of sand. In 2008 in Ashley and Mississippi Counties, AR, nematicide treatment by soil zone resulted in 36% and 42% reductions in the amount of nematicide applied relative to whole-field application. In 2007 in Bamberg County, SC, there was a strong positive correlation between increasing population densities of Meloidogyne incognita and increasing sand content. Trials conducted during 2007 and 2009 in South Carolina against Hoplolaimus columbus showed a stepwise response to increasing rates of aldicarb in zone 1 but not in zones 2 and 3. Site-specific application of nematicides has been shown to be a viable option for producers as a potential management tool against several nematode pathogens of cotton.

Effect of zinc supplementation in children with asthma: a randomized, placebo-controlled trial in northern Islamic Republic of Iran.

There are conflicting reports about the benefits of zinc supplements in childhood asthma. This study examined the effect of zinc supplementation in children with asthma attending an outpatient clinic in Sari, Islamic Republic of Iran. In a randomized, double-blind, placebo-controlled clinical trial over 8 weeks, 284 children on inhaled steroids were allocated to receive zinc supplements (50 mg/day) (n = 144) or placebo (n = 140). Cases and controls had low initial serum zinc concentrations [61.8 (SD 7.3) µg/dL and 60.9 (SD 4.3) µg/dL]. After treatment, mean serum zinc level in the case group was significantly higher [129 (SD 20.4) µg/dL] than in the controls [63 (SD 8.6) µg/dL]. There were no significant differences in IgE levels before and after treatment. The case group showed significant improvements in clinical symptoms such as cough, wheezing and dyspnoea and in all spirometry parameters (FVC, FEV1 and FEV1/FVC).

Is cryotherapy effective in all women with low-grade cervical intraepithelial neoplasia?

OBJECTIVE: This study was designed to investigate the incidence the premalignant and malignant cervical lesions at the 12-month follow-up investigation between cryotherapy and non-cryotherapy groups. PATIENTS AND METHODS: A prospective cohort study was performed in women with CIN 1 and PCB, who were referred to the gynecology clinic at Imam Hospital affiliated to Mazandaran University of Medical Sciences (MAZUMS), Sari, Iran, from February 2015 to November 2019. Of 232 patients, 131 consented to cryotherapy and underwent the treatment, while 101 were unwilling to undergo the treatment. After 12 months, we performed a Pap smear, a colposcopy, and a histopathological investigation of the cervix in both groups. Primary and secondary outcomes were compared between groups. The primary outcome was the comparison of incidence premalignant and malignant cervical lesions in cryotherapy and non-cryotherapy groups. The secondary outcome was a comparison of the accuracy of the Pap smear test versus colposcopy for the detection of premalignant and malignant cervical lesions in women with or without a history of cryotherapy. PATIENTS: Totally, abnormal cytological, positive colposcopic, and positive histopathological findings were reported in 41.56%, 20.26%, and 13.79 %, respectively. By histology biopsy, premalignant and malignant cervical lesions were reported in 28.24% (37/131) and 36.63% (32/101) of women in the cryotherapy and the non-cryotherapy group, respectively. This statistic did not differ significantly between groups (p = 0.78). Pap smears were abnormal in 39.7% and 44.5% of women in the cryotherapy and the non-cryotherapy group, respectively. A positive colposcopy was obtained in 27 (20.6%) and 19 (18.8%) women in the cryotherapy and the non-cryotherapy group, respectively. The diagnostic accuracy of the Pap smear test and colposcopy in detecting cervical neoplasia did not differ in women who had undergone cryotherapy and those who had not (p>0.05). CONCLUSIONS: This prospective study showed that cryotherapy is no appropriate treatment for patients with CIN1 and PCB.

The impact of maternal measles-rubella immunization on the 12-month-old infant's immune response to measles-mumps-rubella vaccine immunogenicity.

This study was conducted to assess the roles of maternal measles-rubella (MR) vaccination before pregnancy on the persistence of passive immunity against MR in their infant before measles-mumps-rubella (MMR) immunization and the effects on the immunogenicity of MMR vaccine. Before and 4-8 weeks after MMR immunization of all healthy 12-month-old infants, sera samples were prepared. According to their mother's history of MR vaccination, infants were divided into two groups. Anti-MR antibodies were measured by the quantitative enzyme-linked immunosorbent assay (ELISA) method. The difference in seroconversion rates and the mean concentration of antibodies (MCA) between the two groups of infants were analyzed by descriptive statistical methods. In total, 7 and 12 sera, all from infants born from MR-vaccinated mothers, were positive against measles and rubella, respectively. The seroconversion rates were 90.5 and 53% in seronegative infants against measles and rubella, respectively, without statistically significant differences between the two groups of infants. However, the MCA differences were significant; measles P = 0.000, rubella P = 0.019. The MR vaccination of mothers may cause the prolongation of passive immunity in their infants, and may influence the immunogenicity of MMR vaccination. This finding should be considered for the optimal scheduling of the first dose of MMR vaccine. Also, the results showed that the immunogenicity of the rubella component of the MMR vaccine was lower than that reported.

Combination therapy with interferon and ribavirin for chronic hepatitis C infection in beta-thalassaemia major.

Treatment of chronic hepatitis C virus (HCV) infection in transfusion-dependent beta-thalassaemia major patients is complicated by existing hepatic siderosis and the fear of ribavirin-associated haemolysis. We evaluated the efficacy and side-effects of combination interferon-alpha (INF) and ribavirin therapy for HCV-infected thalassaemia patients. A total of 17 patients were enrolled (10 nonresponders to INF monotherapy, 7 naive to treatment, mean age 23.1 years) and they received 12 months of combination therapy. The sustained virological response rate 6 months after treatment was 58.8%. Blood transfusion requirements during treatment temporarily increased by 36.6%. Combination therapy was tolerated by, and may be useful for, HCV-infected thalassaemia major patients.

Seroepidemiology of hepatitis E virus infection in 2-25-year-olds in Sari district, Islamic Republic of Iran.

The seroprevalence of hepatitis E virus infection (HEV) in children and young adults was determined in a community-based survey in an area of northern Islamic Republic of Iran. Serum samples were taken from 1080 randomly selected apparently healthy 2-25-year-olds from urban and rural regions of Sari district. Anti-HEV IgG antibodies were detected in 25 individuals (2.3%). Seroprevalence increased significantly with age from 3/255 (1.2%) in children < 10 years to 8/110 (7.3%) in those aged 20-25 years. No differences in HEV status were noted between the sexes. Earlier age at exposure to infection and a higher infection rate were found in people residing in rural areas than in urban areas.

Respiratory viruses in hospitalized children with acute lower respiratory tract infections, Mazandaran Province, Iran.

We conducted this study to determine the contribution of respiratory viruses in 202 hospitalized children (1 mo-5 yr) with clinical evidence of acute lower respiratory tract illness (ALRI). Nasopharyngeal specimens were assayed for viruses detection by indirect immunoflourescent method. Viral agents were identified from 109 (54%) cases (9 cases had dual infection). The most commonly detected virus was parainfluenza virus 3 in 32 (15.8%) cases followed by respiratory syncytial virus 26 (12.9%) parainfluenza 1 and parainfluenza 2 each 13 (6.4%) influenza A 16 (7.4%), influenza B; 7(3.5%), and adenovirus 12 (5.9%). There were no demographic, clinical, radiologic or laboratory parameters except for recurrent wheeze (OR: 4.47; (95% CI: 1.98-10.73) and fever (OR: 3.27; (95% CI: 1.73-6.20), which could differentiate between patients with or without viral etiology.

Pertussis seroimmunity among mother-infant pairs and infant immune response to pertussis vaccination.

This study was designed to evaluate seroprevalence rates of antibodies to pertussis in mothers and their infants, and the immunogenicity of pertussis vaccine in the presence or absence of pertussis antibodies in infants. Blood samples were collected from 110 mother-infants pairs before the first dose of pertussis vaccination and from 69 infants 4-8 weeks after administration of the third dose of DTwP vaccine. Pertussis antibodies were >25 U/mL in 88(78.9%) mothers and 50(45.3%) infants with a mean titer of 67(SD 48.1) and 33.5 (34.7) U/mL, respectively. After administration of three doses of DTwP vaccine, 53(76.8%) infants were seroconverted (MCA titer 87.4 (51.3)U/mL. Immunologic response to vaccination was similar between the two groups of infants; 30/37 (81.1%) of seronegative infants and 23/32 (71.9%) of seropositive infants at pre-vaccination, showed seroconversion after the vaccination (P = 0.36). The results of this study demonstrated that most of the studied mothers were serologically immune to pertussis, and this immunity was transferred to their infants. Pre-vaccination antibody did not affect infants immune response to vaccination.

Knowledge and practices of health care workers and medical students towards universal precautions in hospitals in Mazandaran Province.

This study investigated knowledge of and practices towards universal precautions among 540 health care workers and medical students in 2 university hospitals in Mazandaran Province, Islamic Republic of Iran. Only 65.8% and 90.0% staff in the 2 hospitals and 53.5% of medical students had heard about universal precautions. Overall, there was a low understanding of precautions, except concerning disposal of sharps, contact with vaginal fluid, use of mask and gown or cleaning spilled blood. Health workers had difficulty distinguishing between deep body fluids and body secretions that are not considered infectious. Good practices were reported regarding hand-washing, disposal of needles, and glove, mask and gown usage.

Measles seroepidemiology among adolescents and young adults: response to revaccination.

We evaluated the seroprevalence of measles antibody and response to measles reimmunization in 590 previously vaccinated adolescents and young adults; 263 were seronegative. To differentiate between primary and secondary vaccine failure, anti-measles IgM and IgG titres were assessed again 2-4 weeks after revaccination in 144 (105 seronegative, 39 seropositive) individuals: 75 seronegative participants responded to revaccination anamnestically (P < 0.001) and developed immunity, 11 also showed IgM response (probably primary vaccine failure); 38 seropositive participants remained seroprotected without significant increase in antibody titre (P = 0.577). Primary vaccine failure was 4.7%; secondary vaccine failure was 27.1%. After revaccination, 87.3% were seroprotected.

Occupational back pain in Iranian nurses: an epidemiological study.

The aim of this study was to identify the prevalence and risk factors for low back pain (LBP) in nursing personnel and to analyze how individual and occupational characteristics contribute to the risk of LBP. Following ethical approval, 1226 nurses were randomly recruited from 13 general hospitals in northern Iran. Different questionnaires were designed to cover personal and professional data, the prevalence, and associations of risk factors with LBP. Results indicated that prevalence of LBP in nurses was over 50%. Lifting was the most common mechanism for LBP (30.4%). Prolonged standing and rest were found to be the significant aggravating and relieving factors (57.6% and 59.2%, respectively). Absence from work because of LBP in the month before the questionnaire was completed was reported by 33.7% of the sample. The results demonstrate that the magnitude of LBP among nursing personnel appears to be high and therefore more resources should be allocated to prevent such an injury occurring in the nursing profession.

Rapid reinfection by Giardia lamblia after treatment in a hyperendemic area: the case against treatment.

We selected 40S children aged 1-10 years with Giardia lamblia infection but without abdominal orgastrointestinal complaints for the previous month. For 5 days, 204 received metronidazole 15 mg/kg/day and 201 received B-complex syrup. Stool samples were examined 2-3 weeks and 3 months after treatment and results were tested with chi-squared. Weight and height 6 months after treatment were compared with primary weight and height by Z-score and Student t-test. Metronidazole efficacy at 2-3 weeks was 85.3%. Three months after treatment, 60 were reinfected (34.5%) and 71 had spontaneously cleared (35.3%). Because of high reinfection, spontaneous clearing and treatment failure rates, and the lack of effect on nutritional status or growth, we do not recommend treatment for children with asymptomatic giardia infection.

High sensitive CRP and pentraxine 3 as noninvasive biomarkers of nonalcoholic fatty liver disease.

INTRODUCTION: Nonalcoholic fatty liver disease (NAFLD) has become the most common hepatic disease. Liver biopsy is the gold standard for the diagnosis of NAFLD. To overcome the problems with liver biopsy many studies are being performed to find noninvasive methods for the evaluation of hepatic status. AIM: This study aims to study to role of high sensitive CRP and pentraxine 3 in the setting of NAFLD. PATIENTS AND METHODS: thirty two NAFLD cases and 34 controls were enrolled. All subjects were studied clinically and blood was drawn for para-clinical studies. Liver biopsy was performed for all cases. Levels of hs-CRP and pentraxine were analyzed to find any significant difference for the stages of steatosis and fibrosis based on pathologic findings. RESULTS: Hs-CRP level was higher in nonalcoholic steatohepatitis (NASH) cases versus non-NASH cases. Its level was also increased in higher levels of fibrosis. Pentraxine 3 had no efficacy in differentiating different levels of NAFLD and fibrosis. CONCLUSIONS: Hs-CRP can be used in combination with other biomarkers in the noninvasive evaluation of NAFLD.

Epidemiological survey of the prevalence of intestinal parasites among schoolchildren in Sari, northern Iran.

Parasitic infection is highly prevalent throughout the developing countries of the world. Research on the prevalence of intestinal parasitic infections in various geographic regions is a prerequisite for the development of appropriate control strategies. A cross-sectional study was conducted to determine the prevalence of intestinal parasitic infections among schoolchildren in public primary and secondary schools in the urban areas of Sari, Mazandaran province, northern Iran. The study was conducted from November 2009 to June 2010. A total of 1100 stool samples from 607 males and 493 females aged 7-14 years were examined by direct wet mounting, formalin-ether concentration, and Ziehl-Neelsen and trichrome permanent staining methods. A parental questionnaire for common risk factors was completed for each participant. Mono- or poly-parasitism was detected in 367 (33.3%) of the children (32.6% of males and 34.2% of females). Various species of protozoan or helminth infections were detected: Blastocystis hominis seemed to be the most prevalent parasite (13.5%) followed by Giardia lamblia (10.6%), Entamoeba coli (7.2%), Endolimax nana (1.5%), Enterobius vermicularis (2.2%), Trichostrongylus sp. (2.1%) and Strongyloides stercoralis (1.6%). The prevalence of intestinal parasite infections in females was slightly higher than in males, though without a statistically significant difference (p=0.56). No age association was detected, and a slightly lower positive association with increasing age was observed (p=0.33). A significant association was observed with parents' educational level, household income and practice of hand washing before meals (p<0.01). Although paediatric pathogenic intestinal parasite infections are not more prevalent in this geographical area than in other regions, improvements in personal hygienic conditions and behavioural characteristics is important to completely control parasitic infections in schoolchildren in northern Iran.

Seroprevalence of toxocariasis in schoolchildren in Northern Iran.

This cross-sectional study was carried out on 1210 randomly selected schoolchildren, attending sixteen primary and secondary schools, during the period between November 2005 and June 2006. Parents who accepted to include their children were requested to be present at sampling time and to fill in a simple questionnaire with personal and epidemiological data. Three milliliter of venous blood were taken by vein puncture under sterile conditions from each subject for detection and titration of antibodies to T. canis and eosinophil counts. Total IgG anti-Toxocara antibodies was evaluated by T. canis IgG ELISA kit. According to the manufacture recommendations, an index positivity >11 U was considered positive. Of the 1210 serum specimens tested, an overall seroprevalence for Toxocara antibodies of 25% was obtained. There was no association between positive seroprevalence and age (p = 0.34). Boys and girls differed significantly with regard to Toxocra titre (p = 0.003). Eosinophilia in peripheral blood (> or = 5%) was detected in 24.5% (297/1210) of the population studied, 97/297 (32.8%) of whom were seropositive for toxocariasis. The findings of this study confirmed that infection with Toxocara is quite high and widespread in children in Northern Iran. Therefore, health promotion efforts must be directed at increasing the awareness of the population about the potential zoonotic hazards associated with the disease and how to minimize them.

Effect of zinc supplementation in children with asthma: a randomized, placebo-controlled trial in northern Islamic Republic of Iran

إن هناك تقارير متضاربة عن منافع المقادير الداعمة من الزنك على الأطفال المصابين بالربو. وقد تناولت هذه الدراسة تأثر المقادير الداعمة من الزنك على الأطفال المصابين بالربو ممن يراجعون العيادات في "ساري" في جمهورية إيران الإسلامية؛ وهي دراسة سريرية معشاة للحالات والشواهد ومزدوجة التعمية استمرت أكثر من ثمانية أسابيع وشملت 284 طفلا يعالجون بالستيروئيدات إنشاقا، بعد توزيعهم إلى 144 طفلا تلقوا مقدارا داعما من الزنك [50 ميي غرام/يوم]و 140 طفلا شاهدا. وقد تبين للباحثين أن لدى كل من أطفال الحالات والشواهد مستويات منخفضة من الزنك في البدء [61.8 +/- 7.3 مكروغرام/ ديسي لتر للحالات، و60.9 +/- 4.3 مكروغرام/ ديسي لتر للشواهد]. أما بعد المعالجة فقد أصبح وسطي مستوى الزنك في المصل في مجموعة الحالات 129 +/- 20.4 ميي غرام/ديسي لتر وهو أعلى بمقدار يعتد به إحصائيا مما لدى الشواهد وهو 63 +/- 8.6 ميي غرام/ديسي لتر. ولم يكن هناك أي اختلافات يعتد بها إحصائيا في مستوى الغلوبولن المناعي E قبل وبعد المعالجة. وأظهرت مجموعة الحالات تحسنا في الأعراض السريرية مثل السعال والأزيز وضيق النفس وجميع نتائج القياسات التنفسية [السعة الحيوية القسرية، والحجم الزفيري القسري في الثانية الأولى، والنسبة بين الحجم الزفيري القسري في الثانية الأولى إلى السعة الحيوية القسرية]

ABSTRACT There are conflicting reports about the benefits of zinc supplements in childhood asthma. This studyexamined the effect of zinc supplementation in children with asthma attending an outpatient clinic in Sari, IslamicRepublic of Iran. In a randomized, double-blind, placebo-controlled clinical trial over 8 weeks, 284 children oninhaled steroids were allocated to receive zinc supplements (50 mg/day) (n = 144) or placebo (n = 140). Cases andcontrols had low initial serum zinc concentrations [61.8 (SD 7.3) μg/dL and 60.9 (SD 4.3) μg/dL]. After treatment,mean serum zinc level in the case group was significantly higher [129 (SD 20.4) μg/dL] than in the controls [63 (SD8.6) μg/dL]. There were no significant differences in IgE levels before and after treatment. The case group showedsignificant improvements in clinical symptoms such as cough, wheezing and dyspnoea and in all spirometryparameters (FVC, FEV1 and FEV1/FVC).

RÉSUMÉ Les informations concernant les bénéfices d'une supplémentation en zinc chez l'enfant asthmatique sontcontradictoires. L'étude a examiné les effets d'une supplémentation en zinc chez des enfants asthmatiques suivisdans un service de consultations externes à Sari (République islamique d'Iran). Dans un essai clinique randomiséd'une durée de 8 semaines, en double aveugle et contrôlé contre placebo, 284 enfants sous corticostéroïdesinhalés ont été répartis entre un groupe recevant une supplémentation en zinc (50 mg/jour) (n = 144) et un groupesous placebo (n = 140). Les cas comme les témoins présentaient des concentrations sériques en zinc initialesfaibles [61,8 (E.T. 7,3) μg/dL et 60,9 (E.T. 4,3) μg/dL]. Après le traitement, la concentration sérique en zinc moyennedans le groupe des cas était nettement supérieure [129 (E.T. 20,4) μg/dL] par rapport au groupe des témoins [63(E.T. 8,6) μg/dL]. Aucune différence significative n'a été observée dans les taux d'IgE avant et après le traitement.Dans le groupe des cas, des améliorations significatives des symptômes cliniques ont été observées, notammentla toux, les sifflements respiratoires, la dyspnée et tous les paramètres spirométriques (CVF, VEMS et VEMS/CVF).