A Dosimetric evaluation of a high dose rate cobalt-60 brachytherapy source using shielded, single and multi-channel cylinder applicators for gynecological cancers

Vaginal brachytherapy is a standard method for preventing the recurrences of malignancies in the treatment of gynecological cancers. Cylindrical applicators are usually employed in high dose rate cobalt-60 source brachytherapy after abdominal hysterectomy or bilateral salpingo-oophorectomy treatment. The aim of this study is to conduct an assessment of dosimetric properties of single channel, multichannel, and shielded cylinder applicators. This study utilizes a pelvis phantom with three different volumes of bladder and rectum to perform dose measurement around the cylindrical applicators. GAFCHROMIC EBT3 model film was used to measure dose distributions in water phantom around the bladder, rectum, applicator, and CTV. In order to properly compare the performance of the shielded applicator with multichannel and single channel applicators, we consider the both cases of a one-sided CTV and two CTVs placed on both sides of the vagina. Dose-volume histograms analysis shows no statistically significant difference in tumoral region for the two types of CTV between cylindrical applicators. The V_120%, V_100% and D_95% values of target volume were 47.36%. 91.46%, and 3.99Gy for multi-channel cylinder applicator, 60.2%, 95.02%, and 3.99Gy for single channel cylinder applicator, respectively. Statistical analysis reports D_0.1cc, D_1cc, and D_2cc for the multichannel applicator demonstrates a significant dose reduction in bladder compared with single channel. The V_120%, V_100%, and D_95% values of target volume were 55.50%. 97.90%, and 3.91Gy for multi-channel cylinder applicator with four active channels (MCC-4), 41.56%, 92.10%. and 4.13Gy for shielded cylinder applicator, respectively. Statistical analysis reports D_0.1cc, D_1cc and D_2cc for the MCC-4 demonstrates a noticeable dose reduction in bladder and rectum compared with Shielded channel. The results indicate that employing multichannel applicator in vaginal high dose rate cobalt-60 source brachytherapy can reduce the received dose to organs at risk without any significant loss of received dose in CTV, which is contributed to its asymmetric or symmetric dose distribution that depend on which channels are activated.

High dose rate192Ir versus high dose rate60Co brachytherapy: an overview of systematic reviews of clinical responses of gynecological cancers from 1984 to 2020

The Purpose. Radioisotope of192Iradium (192Ir) has a half-life (74 days) and is not easily accessible in developing countries. As a result, by the time source shipment clearance and the customs paperwork are completed, a large proportion of useful activity had already been decayed away. In fact,60Cobalt (60Co) remote afterloading systems are commercially available by many venders. As a result, it may well become an alternative source to192Ir and conform many of these challenges. The aim of this study is that to report clinical responses of different types of gynaecological cancers treated with high dose rate (HDR)192Ir and HDR60Co brachytherapy in order to check whether HDR60Co could be used as an alternative brachytherapy, source to HDR192Ir.Materials and Methods. A retrospective study of clinical responses of different types of gynaecological cancers, staged from I to IV according to recommendations of International Federation of Gynaecology and Obstetrics (FIGO), treated by brachytherapy alone, radiotherapy alone (combined brachytherapy and radiotherapy) and combined radiotherapy and chemotherapy (brachytherapy, radiotherapy and chemotherapy) between 1984 and December 2020 was conducted. The patients were treated with external beam radiotherapy 45-51 Gy boosted with HDR192Ir and HDR60Co afterloading brachytherapy of 18-30 Gy to point A.The results. The study scrutinized the data of 11086 patients with different types of gynaecological cancers. Most of the patients, 70 percent of them, were diagnosed with gynaecological cancers in stages II and III. For patients treated with192Ir brachytherapy source 5-years overall survival rate (OS), local control, 2-years, 5-years and 10-years disease free survival (DFS), complications of gastro-intestine (GI) and complications of genito-urinary (GU) were 63.5%, 92%, 72.6%, 64.07%, 43.75%, 3.9% and 5.92%, but for those treated with60Co they were 57.7%, 86.63%, 82.5%, 53.35%, 43.75%, 4.8% and 3.7%, respectively.Conclusions.The use of HDR60Co brachytherapy has the capacity to produce overall survival rate and disease control in patients with carcinoma of the gynaecology comparable to that reported for HDR192Ir brachytherapy. Currently, the toxicity and damage of the normal tissues and radiation-related second cancers are of a similar incidence to that of standard HDR192Ir brachytherapy. Source exchange frequency is not a serious concern because it requires less frequency of replacement, and commissioning can be accomplished within years; hence, replacing HDR192Ir with HDR60Co brachytherapy achieves significant cost saving. Therefore, we recommend that60Co source ought to be the first choice for low resource radiotherapy setting as it offers economic advantages over192Ir and have comparable clinical outcomes to that of192Ir source.

Multimodal exploration of non-motor neural functions in ALS patients using simultaneous EEG-fNIRS recording

OBJECTIVE

Despite the high prevalence of non-motor impairments reported in patients with amyotrophic lateral sclerosis (ALS), little is known about the functional neural markers underlying such dysfunctions. In this study, a new dual-task multimodal framework relying on simultaneous electroencephalogram (EEG) and functional near-infrared spectroscopy (fNIRS) recordings was developed to characterize integrative non-motor neural functions in people with ALS.

APPROACH

Simultaneous EEG-fNIRS data were recorded from six subjects with ALS and twelve healthy controls. Through a proposed visuo-mental paradigm, subjects performed a set of visuo-mental arithmetic operations. The data recorded were analyzed with respect to event-related changes both in the time and frequency domains for EEG and de/oxygen-hemoglobin level (HbR/HbO) changes for fNIRS. The correlation of EEG spectral features with fNIRS HbO/HbR features were then evaluated to assess the mechanisms of ALS on the electrical (EEG)-vascular (fNIRS) interrelationships.

MAIN RESULTS

We observed overall smaller increases in EEG delta and theta power, decreases in beta power, reductions in HbO responses, and distortions both in early and later EEG event-related potentials in ALS subjects compared to healthy controls. While significant correlations between EEG features and HbO responses were observed in healthy controls, these patterns were absent in ALS patients. Distortions in both electrical and hemodynamic responses are speculated to be associated with cognitive deficits in ALS that center primarily on attentional and working memory processing.

SIGNIFICANCE

Our results highlight the important role of ALS non-motor dysfunctions in electrical and hemodynamic neural dynamics as well as their interrelationships. The insights obtained through this study can enhance our understanding of the underlying non-motor neural processes in ALS and enrich future diagnostic and prognostic techniques.

The prevalence of dental anxiety and fear in patients referred to Isfahan Dental School, Iran

BACKGROUND

Dental anxiety and fear are major complications for both patient and dental care provider. The purpose of this study was to assess the prevalence of dental anxiety and fear in patients who referred to Isfahan Dental School and their relation to their age, gender, educational level, past traumatic experiences and frequency of dental visits.

MATERIALS AND METHODS

In this cross-sectional study, 473 patients were provided with a questionnaire including three sections. First section contained questions concerning their age, gender, educational level, frequency of dental visits, reasons for irregular attendance and existence of past traumatic experiences. Second section comprised a Farsi version of Modified Dental Anxiety Scale (MDAS); and third included a Farsi version of dental fear survey (DFS). Data were analyzed by t-test, ANOVA, Pearson and Spearman correlation tests.

RESULTS

The prevalence of dental anxiety among the study population was 58.8%. No correlation was found between age and MDAS (r = -0.08, P = 0.07) and DFS (r = -0.03, P = 0.53). Women demonstrated higher anxiety (P < 0.001) and fear (P = 0.003). Education had no significant effect on dental anxiety (r = -0.046, P = 0.32) and dental fear (r = -0.017, P = 0.79). Previous traumatic experiences were found to result in elevated anxiety and fear (P < 0.001). There was an inverse relationship between frequency of dental attendance and anxiety (r = -0.128, P = 0.008).

CONCLUSIONS

Within the limitations of this study, anxiety associated with dental treatment was widespread in the study population. Dental fear and anxiety were not affected by age or education level. Dental fear and anxiety were higher in women. In addition, people who visited the dentist more regularly and individuals without previous traumatic dental experiences were less anxious.

Field evaluation of permethrin long-lasting insecticide treated nets (Olyset(®)) for malaria control in an endemic area, southeast of Iran

Long lasting insecticide treated nets (LLINs) have been advocated as an effective tool for prevention and control of malaria. Olyset net was the first LLINs which became commercially available and obtained WHO approval. According to the national strategic plan on evaluation of Olyset net, a field trial was conducted to determine the efficacy of these nets against malaria vectors in an endemic area in the southeast of Iran. Fourteen villages with similar topographical and epidemiological situations were selected and randomly assigned to two clusters of the study: Olyset net and untreated net. Distribution of nets was carried out to cover 100% of the population in Olyset net and untreated net cluster. Anopheline mosquitoes were collected monthly using different WHO standard methods in both areas to determine their abundance, feeding pattern and resting behaviour. Human blood index was determined using ELISA test. Additionally, Olyset nets were evaluated for their biological activity using WHO cone bioassay test by susceptible colony of Anopheles stephensi (Beech strain) and then for insecticide residues by employing high performance thin layer chromatography. Malaria incidence was measured by passive and active case detection from all study population. In total 2115 adult anopheline mosquitoes were collected and identified using morphological characters. They comprised of seven species: Anopheles dthali (Liston), A. culicifacies (Giles), A. stephensi (Liston), A. superpictus (Grassi), A.fluviatilis (James), A. moghulensis (Christophers) and A. turkhudi (Liston). A. dthali, A. culicifacies and A. stephensi were most prevalent species in both areas. In the Olyset net study area, there was a significant reduction of 41.1%, 54.4%, 59.39% and 64.1% in the indoor-resting density of A. culicifacies, A. stephensi, A. dthali and A. superpictus, respectively, with an overall reduction of 39.3% in total mosquitoes in comparison with untreated net area. A significant reduction was also observed in human blood index of vector species in the Olyset net villages. Bioefficacy test results of Olyset nets showed that the median knockdown time was 1.48 and 3.25min, while the average mortality rate was 100% and 72.3%±7.07 in baseline and after 1 year of intervention, respectively. The average permethrin content reached to 68.31% (683.1mg/m(2)) of the initial insecticide dose of 937±21.69mg/m(2) (nearly 1000mg/m(2)) at the end of intervention. Malaria incidence was reduced by 96.6% and 64.8% in the village with Olyset nets and in the villages with untreated nets, respectively. During intervention period, there was a reduction of 93.2% in malaria incidence in Olyset net area as compared to the untreated area. This study indicated that Olyset nets have a major impact on malaria vectors and disease burden; therefore it could be recommended as an effective personal protection tool for malaria control in malarious areas.

Effectiveness of ultrasound and ultraviolet irradiation on degradation of carbaryl from aqueous solutions

BACKGROUND

Carbaryl (1-naphthyl-N-methyl carbamate) is a chemical in the carbamate family used chiefly as an insecticide. It is a cholinesterase inhibitor and is toxic to humans and classified as a likely human carcinogen. In the present study, the degradation of the carbaryl pesticide was investigated in the laboratory synthetic samples of tap water, in the effect of sonolysis and photolysis processes.

METHODS

This study was conducted during 2006-7 in Chemistry and Biochemistry of Pesticides Laboratory in Tehran University of Medical Sciences (TUMS) in Iran. The carbaryl (80%) was used for preparing samples. First concentration of all samples were 4 mg/l. Sonochemical examinations in ultrasound reactor was done in two 35, 130 Hz, and 100 w, and three time. Photolysis examinations has done in the effect of 400 w lamp and moderate pressure and 6 time, then the amount of pesticide in the samples has been measured by the High Performance Thin Layer Chromatography (HPTLC) method.

RESULTS

The highest degradation in photolysis process after 1 hour in the 35 KHz was 35%, and in the 130 KHz was 63%. Degradation of carbaryl at 130 KHz is higher than 35 KHz at the same time. Carbaryl elimination was increased by arise frequency and exposure time. After 8 min in photolysis, 100% omitting has been showed.

CONCLUSION

Degradation of carbaryl in high frequency ultrasound wavelength was more than low frequency. Degradation of carbaryl in water, combination of high frequency ultrasound wave length and UV irradiation was considerably more effective than ultrasound or ultraviolet irradiation alone.

Designing of a laboratory model for evaluation of the residual effects of deltamethrin (K-othrine WP 5%) on different surfaces against malaria vector, Anopheles stephensi (diptera: culicidae)

BACKGROUND & OBJECTIVES

Deltamethrin plays an important role in controlling malaria vectors, and is used in indoor residual spraying and manufacture of long-lasting insecticidal mosquito nets. The residual activity of deltamethrin (K-othrine WP 5%) @ 25 mg/m(2) was studied in laboratory conditions on different surfaces.

METHODS

The surfaces were made artificially with different building materials such as mud, plaster, cement and wood in the laboratory. The surfaces were mounted inside petri-dishes (diam: 20 cm) and wood surface was prepared separately. The prepared surfaces were attached to the walls and deltamethrin was applied using standard Hudson pump sprayer with a discharge rate of 757 ml/ min or 0.2 gal/min. The spraying was conducted at standard rhythm as recommended by WHO. After application all the sprayed surfaces were transferred into the special wooden boxes designed for this purpose. The surfaces were maintained at laboratory conditions. The WHO's recommended bioassay kit and method was used during this study.

RESULTS

Bioassays on Anopheles stephensi Liston showed that the persistence of deltamethrin on different surfaces (>70% mortality) was around 4 months on plaster (Mortality = 77+/-6.2%), 2 months on mud (76.9+/-6.8%), 4.5 months on cement (79+/-3.2%), 4 months on wood (71.7+/-6.8%) and 4 months on filter papers (82.3+/-5.4%).

INTERPRETATION & CONCLUSION

The results of this study on residual effects of deltamethrin WP 5% (25 mg/m(2)) are highly concordant with two field bioassays carried out in a malarious area at south-eastern Iran. This method can be replaced by the field bioassay tests which are time consuming and costlier.

High Performance Thin Layer Chromatography Analysis of Deltamethrin Residue on the Impregnated Bed Nets during a Leishmaniasis Control Program in Iran

BACKGROUND

The control of leishmaniasis, a tropical neglected disease, has been concern of Iranian health authorities due to the increasing number of cases during the last two decades. The objective of this study was to determine deltamethrine residue on the impregnated bed nets using HPTLC technique in a leishmaniasis control program in Iran.

METHODS

During this experimental study, a total of 130 small pieces of polyester netting were sewn to top, upper, and lower sides of some bed nets and then were impregnated with deltamethrin. The treated bed nets were distributed in Isfahan and Mashhad areas in April 2003. The samples were cut randomly after impregnation intervals. Deltamethrin was extracted using acetone from samples and the extract was applied for spotting onto plates. The plates were developed with n-hexane: ethyl acetate, 90+10(v/v), as a mobile phase in a Camage chamber. The qualifying of residue was observed in UV cabinet with λ=254 nm wavelength. Data were analyzed using SPSS version 11.5. and Stata Version 8. A three way ANOVA was used to compare the means of deltamethrin residue in each area, group and measuring time. The Kruskal-Wallis test was used to compare the means of residue for each of these factors with the control separately.

RESULTS

The retardation factor of deltamethrin was calculated 0.50±0.02. The residues of deltamethrin persisted well on impregnated nets at least for 15 weeks after impregnation. No significant difference could be detected in the loss of residue of insecticide in comparison to measuring times and positions of sampling pieces on the bed nets in these areas.

CONCLUSION

Based on the results of the present study the use of HPTLC technique is recommended instead of other chromatographic methods for analysis of insecticide residue on the impregnated bed nets.

Renal allograft biopsies with borderline changes: predictive factors of clinical outcome

The clinical outcome and appropriate management for patients showing 'borderline changes' on allograft biopsy after renal transplantation is still controversial. In an attempt to identify predictive factors of clinical outcome of patients with such lesions, we reviewed the clinical course of 91 patients with borderline changes. Multivariate analysis revealed significant and independent effects of histological stage (i + t < or = or > 2) and time to borderline changes (< or = or > 3 months after transplant) on serum creatinine levels at 1 year from borderline changes episodes (respectively, p = 0.04 and p = 0.02) and only a significant effect of time to borderline changes on serum creatinine levels at 2 years (p = 0.005). Renal function at 1 year and 2 years as 5- and 8-year graft survival were not significantly different in the group of patients treated with antirejection therapy (T group, n = 49) compared with the untreated group (UT group, n = 42). This study strongly suggests that borderline changes with histological score (i + t) > 2 and late episodes of borderline changes should be considered to be of poor prognosis.

Minimal change nephrotic syndrome and classical Hodgkin's lymphoma: Report of 21 cases and review of the literature

Minimal change nephrotic syndrome (MCNS) is described as a paraneoplastic manifestation of classical Hodgkin's lymphoma (cHL). We reassessed the pathophysiological and clinical significance of this association. A retrospective study was performed to evaluate a cohort of adult patients who developed MCNS and cHL. Twenty-one patients recruited in 15 French centers were analyzed. cHL was associated with inflammatory and general symptoms in most cases. The morphological subtype was predominantly nodular sclerosis (71.4%). MCNS appeared before the diagnosis of lymphoma in eight patients (38.1%) and in this case, it was characterized by a nephrotic syndrome (NS) frequently resistant (50%) or dependent (12.5%) to steroid treatment. Interestingly, diagnosis (3-120 months after MCNS) and effective treatment of the hemopathy were associated with the disappearance of the MCNS. cHL was diagnosed before MCNS in nine patients (42.9%), and in this case, glomerulopathy was associated with cHL relapse in 55.5% of cases. In four patients (19%), the two diseases occurred simultaneously. Extensive immunohistochemical study of lymph nodes was performed in eight patients and did not reveal particular features. In conclusion, MCNS associated with cHL is frequently dependent or resistant to steroid regimen, but remission of NS is obtained with the cure of lymphoma.

[The benefits of new immunosuppressive treatments in adult kidney transplantation]

NEW KNOWLEDGE: Over the last few years, improved knowledge of the immunological mechanisms underlying transplant rejection have resulted in the development of new immunosuppressive agents capable of selectively blocking various steps of the immune response. NEW MOLECULES: The review focuses on new immunosuppressive drugs that have been developed for clinical use in renal transplantation and mechanism of action, advantages and side effects will be discussed for each of them. Neoral is a cyclosporin microemulsion, characterized by more consistent absorption. Tacrolimus shares with cyclosporin an ability to inhibit calcineurin but presents some differences. Mycophenolate mofetyl selectively inhibits purine synthesis and lymphocyte proliferation; it is easy to use and has been found effective in large clinical trials. Rapamycin and RAD are two related molecules that inhibit signal transduction by cytokines to T-cells, their use in transplant therapy remains to be determined. Anti-interleukin-2 receptor antibodies are also reviewed; they are easy to use and have been found effective. NEW STRATEGIES: These new immunosuppressive drugs provide new approaches in transplant therapy to improve their efficacy and safety.

Biocompatibility of various light-curing and one conventional glass-ionomer cement

The purpose of this study was to determine and to compare the cellular compatibility of modern light-curing (lc) glass-ionomer cements (GICs) to one conventional (co) GIC. The following materials were investigated: Ionoseal (IS, lc) (VOCO, Germany), Vitrebond (VB, lc) (3M, USA), Compoglass (CG, lc) (Vivadent, FL) and Ketac Fil Applicap (KF, co) (ESPE, Germany). From all GICs, equally sized specimens (height 2 mm, diameter 5 mm) were polymerized or set according to the instructions of the manufacturers. Various extracts of all specimens were obtained by subsequent elutions. Human primary fibroblasts of the attached gingiva (HGF) and permanent mouse fibroblasts (3T3) were used for the experiments. HGF and 3T3 cells were exposed to the extracts of all materials for 48 h. Growth inhibition due to cytotoxic effects was determined by staining the cultures with Hoechst 33342 (determination of DNA and cell vitality). It was found that the material CG induced no growth inhibition in any of the assays. Proliferation of HGF was not, or only slightly, inhibited by the extracts of the materials IS and KF, whereas severe alterations were caused by the extracts of the material VB. Growth of 3T3 cells was only moderately or slightly reduced by the extracts of materials IS and KF respectively, but was severely or totally inhibited by all extracts of VB. From our results we conclude that the GIC VB is very cytotoxic and therefore may also induce alterations in vivo. All other investigated GICs revealed excellent (CG), or good (IS, KF) cellular compatibility.

Glomerular diseases in children. "The Iranian experience"

A total of 411 children, aged from 0.3 to 18 years, suffering from glomerular diseases, were studied by renal biopsy between 1976 and 1985. The clinical presentation included nephrotic syndrome (79% of cases), renal failure (43%), and arterial hypertension (38%). In all, 177 cases presented with primary nephrotic syndrome; all had complicated courses and most were either corticosteroid-dependent or -resistant. Only 26.6% had minimal change disease on renal biopsy; 56.5% had focal-segmental sclerosis; and immunofluorescent deposits were observed in half of the group. Acute poststreptococcal (36 cases), mesangiocapillary (80 cases), and lupus (34 cases) glomerulonephritis occurred frequently; IgA glomerulopathy (10 cases) and haemolytic uraemic syndrome (6 cases) were uncommon. Glomerular crescents were observed in 71 cases. These observations illustrate the types of glomerular diseases seen in Iranian children.

A simple and safe technique for tibial lengthening

This is a report of long-term results and complications in 62 patients. Closed tibial osteotomy, direct tibial distraction, and simultaneous indirect proximal fibular epiphyseal distraction are the essential features of this new technique. Fibular osteotomy and complications from tibiofibular synostosis are eliminated. Bone graft and plating procedures have been proven to be unnecessary. The patient is ambulated immediately. Hospitalization has been reduced to a few days.

External fixator in management of fractures and leg lengthening

The authors review the fundamental scientific factors that govern the healing of bone and conclude that they form a physiologic basis for the preferred use of external fixation in the management of fractures of the long bones as well as in the management of leg lengthening.

33 cases of multiple myeloma with massive bone destruction. Report of a 10-year study in northeastern Iran

The authors studied 133,856 admissions over a ten-year period and found 138 cases of primary tumors of bone. Of these only 33 were of multiple myeloma. Incidence, clinical manifestations, age, sex and ecology are reported and the effect of four different chemotherapy regimens are evaluated.