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OBJECTIVES: Limited data exist on the adoption of rituximab biosimilars vs the reference product by indication. Available data from real-world studies comparing rituximab biosimilar and reference use have focused predominantly on oncology indications. This is the first study to assess the utilization of the 3 US rituximab biosimilars vs the reference product. STUDY DESIGN: Comparative analysis. METHODS: Deidentified real-world data of rituximab, rituximab-abbs, rituximab-pvvr, and rituximab-arrx dispensations between December 31, 2018, and February 1, 2022, were extracted using Trisus Medication Compare (The Craneware Group). The primary outcome was rituximab reference vs biosimilar utilization for oncology vs nononcology indications. Results were stratified by on-label and off-label use and treatment settings. RESULTS: A total of 28,025 encounters were captured for rituximab and its biosimilars across 193 facilities (rituximab: n = 23,395; biosimilars, n = 4631 [rituximab-abbs: n = 2550; rituximab-pvvr, n = 2081; rituximab-arrx: n = 0]). Rituximab reference had higher dispensations for oncology (78.4%) and nononcology (88.3%) indications than its biosimilars (21.6% and 11.7%, respectively; P < .01). The 3-year annual trends from 2019 to 2021 revealed decreased rituximab reference utilization (99.99% to 40.1%) and increased biosimilar use (0.01% to 59.9%). Most oncology dispensations were on label (94.5%), whereas most nononcology dispensations were off label (73.6%; P < .01). A higher proportion of biosimilar use was attributed to on-label indications (67.7%; off-label, 32.2%) compared with rituximab reference (58.0% vs42.0%, respectively; P < .01). Nonacademic settings showed higher biosimilar adoption than academic settings (22.2% vs 10.3%, respectively; P < .01). CONCLUSIONS: Real-world evidence shows an increase in rituximab biosimilar adoption over time, with higher adoption for oncology vs nononcology indications and in nonacademic settings.
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Medicamentos Biossimilares , Humanos , Rituximab/uso terapêutico , Medicamentos Biossimilares/uso terapêutico , Oncologia/métodosRESUMO
BACKGROUND AND PURPOSE: Peer teaching and serious gaming are effective pedagogical approaches to actively engage learners, foster collaboration, and promote student accountability for self-directed learning. Literature describing how students learn about and are assessed on knowledge of newly approved medications is lacking. The objective of this project is to describe the design and implementation of a peer-taught virtual educational gaming activity, assess impact on knowledge of newly approved medications, and describe student perceptions of the activity. EDUCATIONAL ACTIVITY AND SETTING: Pharmacy students in the fourth professional year developed and delivered a topic discussion focusing on newly approved medications to peers utilizing a virtual escape room gaming format. The activity was delivered via Zoom, Version 4.6.9 (Zoom Video Communications, Inc). A pre- and post-activity knowledge-based assessment and perception-based questionnaire were administered to participants. Observations regarding teamwork and communication were collected by facilitators. FINDINGS: Sixteen students participated in this activity. Mean scores on the knowledge quiz were higher post-activity compared to pre-activity (8.1 vs. 6.3). The activity was perceived positively by participants with 100% of respondents agreeing or strongly agreeing that they "enjoyed the escape room theme for the activity and would recommend it to a friend." Zoom was perceived an effective platform to deliver this activity. All facilitators observed students working effectively as a team to complete the activity. SUMMARY: Virtual gaming developed and facilitated by peer teachers may be an effective method for delivering educational content and positively influencing student learning.
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Currículo , Aprendizagem , Humanos , Avaliação Educacional/métodos , Grupo Associado , EscolaridadeRESUMO
PURPOSE: A proportion of 10 to 30% of patients treated by chemoradiotherapy followed by total mesorectal excision surgery for a locally advanced rectal cancer can achieve a complete pathological response. We aimed to identify predictive factors associated with complete pathological response or no response and to assess the impact of each response on survival rates. PATIENTS AND METHODS: Patients treated with long course chemoradiotherapy for locally advanced and/or node positive rectal cancer from 2010 to 2016 were retrospectively reviewed. Statistical analysis was carried out to determine predictors of tumor regression and treatment outcomes. RESULTS: Records were available on 70 patients. In the univariate analysis, clinical factors associated with complete tumor response were tumor mobility in digital rectal examination (P=0.047), a limited parietal invasion (P=0.001), clinically negative lymph node (P<0.001) and a circumferential extent greater than 50% (P=0.001). On the other hand, a T4 classification and an endoscopic tumor size greater than 6cm were associated with no response to treatment (P=0.049 and P=0.017 respectively). On multivariate analysis, T2 clinical classification and N0 statement before treatment were independent predictive factors of pathologic complete response (P<0.001 and P=0.001) and a delayed surgery after 12 weeks was associated with no response to treatment (P=0.001). CONCLUSION: The identification of predictive factors of histological response may help clinicians to predict the prognosis and to propose organ preservation for good responders.
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Quimiorradioterapia Adjuvante , Terapia Neoadjuvante/métodos , Neoplasias Retais/patologia , Neoplasias Retais/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Antimetabólitos Antineoplásicos/administração & dosagem , Capecitabina/administração & dosagem , Exame Retal Digital , Feminino , Humanos , Linfonodos/patologia , Masculino , Pessoa de Meia-Idade , Neoplasias Retais/mortalidade , Reto/cirurgia , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento , Carga TumoralRESUMO
OBJECTIVES: Anti-carbamylated protein antibodies (anti-CarP Abs) are present in patients with RA, however, their association with bone loss is not confirmed. The purpose of this study was to determine the relation between the serum level of anti-CarP Abs in premenopausal RA women and disease activity and bone loss. METHODS: This case-control study was conducted on 48 premenopausal women with RA and 48 matched healthy premenopausal women. All RA women were subjected to clinical examination, disease activity assessment using the 28-joint DAS (DAS28) and Clinical Disease Activity Index (CDAI), functional assessment using the HAQ, physical activity assessment using the International Physical Activity Questionnaire (IPAQ), fatigue assessment using the Modified Fatigue Impact Scale (MFIS), serological tests as well as anti-CarP Abs using ELISA. Moreover, the BMD was measured by DXA and plain X-ray of both hands was done to assess juxta-articular osteopenia and erosions. RESULTS: The anti-CarP Abs level was significantly higher in RA patients than in healthy controls. The serum level of anti-CarP Abs had a significant positive correlation with the RA DAS28, CDAI, HAQ, MFIS and original Sharp score, while a significant negative correlation was present with the IPAQ. Anti-CarP Abs were negatively correlated with either spine BMD or Z-score and positively correlated with the original Sharp score. CONCLUSION: Anti-CarP Abs were higher in premenopausal RA women compared with older and BMI matched healthy women. Anti-CarP Abs are associated with higher RA disease activity, increased disability and fatigability and decreased physical activity. Moreover, anti-CarP Abs are associated with systemic trabecular bone loss as well as local bone loss.
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Artrite Reumatoide/patologia , Autoanticorpos/imunologia , Osteoporose/imunologia , Pré-Menopausa/imunologia , Carbamilação de Proteínas/imunologia , Adulto , Artrite Reumatoide/imunologia , Estudos de Casos e Controles , Feminino , Humanos , Pessoa de Meia-Idade , Osteoporose/patologia , Índice de Gravidade de DoençaRESUMO
INTRODUCTION: WHO warned against a dramatic impact of COVID-19 in Africa unless adequate response strategies are implemented. Whatever the strategy, the role of health staff is pivotal. Objective: Assess knowledge and perception of the response to COVID-19 among health staff. METHODS: we used a convenience non probabilistic sample to conduct a survey with a self-administered questionnaire from April 14 - 29, 2020 at the Bafoussam Regional Hospital (BRH). All the staff was invited to participate. Analyses were done with Microsoft Excel 2010 and Epi-Info version 7.1.5.2. RESULTS: response rate was 76.1% (464/610). Mean age (SD) was 35.0 (8.9) years. Sex ratio (M/F) was 101/356. Nursing/midwifery staff (56.8%) and in-patients units (49.94%) were predominant. Origin and transmission of SARS-CoV-2 were poorly known while knowledge of clinical signs and the role of laboratory tests were good. For 53.2% of respondents all therapeutic regimens are supportive and only 31.6% trusted state-recommended drugs. For 169 of respondents (36.9%), herbal remedies prevent/cure COVID-19. Seventy percent (70%) felt they were not knowledgeable enough to handle COVID-19 cases. Eighty-five point six percent (85.6%) thought the BRH had insufficient resources to fight COVID-19 and 55.6% were dissatisfied with its response (weaknesses: medicines/technologies (74.5%), service delivery (28.1%), staff (10.9%)). Sixty-eight percent (68%) reported insufficient protection on duty. Seventy-six point five percent (76.5%) reported a drop in non-COVID-19 services. Eighty-five point five (85.5%) percent said they complied with community preventive measures. For 44% of respondents, regulations on COVID-19 corpses should be made more culture-sensitive. Fifty one point two percent (51.2%) of respondents were against vaccine trial in their community. CONCLUSION: knowledge was poor and perception of the response to COVID-19 was unfavourable.
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COVID-19/epidemiologia , Conhecimentos, Atitudes e Prática em Saúde , Recursos Humanos em Hospital/estatística & dados numéricos , Adulto , Idoso , Atitude do Pessoal de Saúde , COVID-19/terapia , Camarões , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Adulto JovemRESUMO
BACKGROUND: According to the WHO, nearly 24% of the global disease burden is attributable to environmental risk factors (RFs). People living in periurban areas are particularly at risk due to lack of basic sanitation requirements. OBJECTIVE: To investigate the possible association between environmental RFs and disease prevalence for a community living in a periurban area in Alexandria, Egypt. MATERIALS AND METHODS: A cross-sectional study was conducted in 2012. The study sample consisted of 355 families. An interviewing questionnaire and an observation checklist were used for data collection. In addition, 10 drinking water samples were randomly collected for physical, chemical, and bacteriological analyses. The questionnaire included questions on indoor environmental RFs as well as morbidity in the study sample, and the observation checklist covered outdoor environmental RFs. The environmental risk was determined using a risk score whose calculation was based upon the presence/absence of 10 indoor and 12 outdoor environmental RFs. The association between risk scores and 14 morbidities was investigated using unconditional logistic regression analysis, expressed as odds ratio (OR) and 95% confidence interval (CI). RESULTS: A significant association was found between the total environmental risk score and respiratory diseases (OR=2.298, 95% CI: 1.231-4.291), diarrhea (OR=2.083, 95% CI: 1.102-3.939), liver diseases (OR=2.491, 95% CI: 1.067-5.819), skin diseases (OR=1.821, 95% CI: 1.012-3.310), and bronchial asthma (OR=2.228, 95% CI: 1.066-4.565). Noncommunicable diseases such as cardiovascular diseases and musculoskeletal diseases did not show any significant association with environmental RFs. CONCLUSION AND RECOMMENDATIONS: Environmental RFs have an adverse impact on health within communities living in periurban areas. It is recommended that sanitation be improved and various outdoor environmental RFs be addressed in these underprivileged areas, as well as health education campaigns be organized aiming at raising the awareness of residents on indoor environmental RFs and ways to prevent them.
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Poluentes Atmosféricos/efeitos adversos , Poluição do Ar/estatística & dados numéricos , Exposição Ambiental/estatística & dados numéricos , Saúde Ambiental/estatística & dados numéricos , Monitoramento Ambiental/estatística & dados numéricos , Saúde da População Urbana , Estudos Transversais , Egito , Humanos , Análise de Regressão , Poluição da Água/estatística & dados numéricosRESUMO
UNLABELLED: In health care facilities, pharmaceutical waste is generally discharged down the drain or sent to landfill. Poor knowledge about their potential downstream impacts may be a primary factor for improper disposal behavior. The objective of this study was to determine the impact of an intervention program on knowledge and practice of health care staff regarding pharmaceutical waste management. The study was designed as a pre/posttest intervention study. Total sample size was 530 in the pre-intervention phase, and then a subsample of 69 individuals was selected for the intervention and the post-intervention phases. Paired-sample t test was used to assess the difference between pretest and follow-up test results. A statistically significant improvement in knowledge and practice was achieved (P<0.001). Poor knowledge and poor practice levels (scores<50%) were found to improve to satisfactory levels (scores≥75%). Therefore, educational programs could be considered as an effective tool for changing health care staff practice in pharmaceutical waste management. IMPLICATIONS: In health care facilities, pharmaceutical waste is generally discharged down the drain or sent to landfill. A lack of knowledge about the potential impacts of this type of waste may be a leading factor in improper disposal behavior. Following an educational program, statistically significant improvement in knowledge and practice of health care staff as regards to pharmaceutical waste management (PWM) was achieved. It is thus recommended that authorities implement training-of-trainers (TOT) programs to educate health care staff on PWM and organize refreshment workshops regularly.
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Resíduos Perigosos , Conhecimentos, Atitudes e Prática em Saúde , Pessoal de Saúde/educação , Preparações Farmacêuticas , Gerenciamento de Resíduos , Adulto , Feminino , Humanos , Masculino , Oriente MédioRESUMO
The objective of this study was to investigate the performance of employing H2O2 reagent in persulfate activation to treat stabilized landfill leachate. A central composite design (CCD) with response surface methodology (RSM) was applied to evaluate the relationships between operating variables, such as persulfate and H2O2 dosages, pH, and reaction time, to identify the optimum operating conditions. Quadratic models for the following two responses proved to be significant with very low probabilities (<0.0001): chemical oxygen demand (COD) and NH3-N removal. The obtained optimum conditions included a reaction time of 116 min, 4.97 g S2O8(2-), 7.29 g H2O2 dosage and pH 11. The experimental results were corresponding well with predicted models (COD and NH3-N removal rates of 81% and 83%, respectively). The results obtained in the stabilized leachate treatment were compared with those from other treatment processes, such as persulfate only and H2O2 only, to evaluate its effectiveness. The combined method (i.e., /S2O8(2-)/H2O2) achieved higher removal efficiencies for COD and NH3-N compared with other studied applications.
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Compostos de Amônio/isolamento & purificação , Peróxido de Hidrogênio/química , Modelos Químicos , Compostos de Sódio/química , Sulfatos/química , Purificação da Água/métodos , Análise da Demanda Biológica de Oxigênio , Oriente Médio , Modelos Teóricos , Oxirredução , Instalações de Eliminação de Resíduos , Poluentes Químicos da ÁguaRESUMO
A combination of persulfate and hydrogen peroxide (S2O8(2-)/H2O2) was used to oxidizelandfill leachate. The reaction was performed under varying S2O8(2-)/H2O2 ratio (g/g), S2O8(2-)/H2O2 dosages (g/g), pH, and reaction time (minutes), so as to determine the optimum operational conditions. Results indicated that under optimum operational conditions (i.e. 120 min of oxidation using a S2O8(2-)/H2O2 ratio of 1 g/1.47 g at a persulfate and hydrogen peroxide dosage of 5.88 g/50 ml and8.63 g/50 ml respectively, at pH 11) removal of 81% COD and 83% NH3-N was achieved. In addition, the biodegradability (BOD5/COD ratio) of the leachate was improved from 0.09 to 0.17. The results obtained from the combined use of (S2O8(2-)/H2O2) were compared with those obtained with sodium persulfate only, hydrogen peroxide only and sodium persulfate followed by hydrogen peroxide. The combined method (S2O8(2-)/H2O2) achieved higher removal efficiencies for COD and NH3-N compared with the other methods using a single oxidizing agent. Additionally, the study has proved that the combination of S2O8(2-)/H2O2 is more efficient than the sequential use of sodium persulfate followed by hydrogen peroxide in advanced oxidation processes aiming at treatingstabilizedlandfill leachate.
Assuntos
Peróxido de Hidrogênio/química , Compostos de Sódio/química , Sulfatos/química , Gerenciamento de Resíduos/métodos , Poluentes Químicos da Água/química , Biodegradação Ambiental , Oxirredução , Poluentes Químicos da Água/análiseRESUMO
The current study investigated the effects of S2O8(2-) and S2O8(2-)/H2O2 oxidation processes on the biodegradable characteristics of an anaerobic stabilized leachate. Total COD removal efficiency was found to be 46% after S2O8(2-) oxidation (using 4.2 g S2O8(2-)/1g COD0, at pH 7, for 60 min reaction time and at 350 rpm shaking speed), and improved to 81% following S2O8(2-)/H2O2 oxidation process (using 5.88 g S2O8(2-) dosage, 8.63 g H2O2 dosage, at pH 11 and for 120 min reaction time at 350 rpm). Biodegradability in terms of BOD5/COD ratio of the leachate enhanced from 0.09 to 0.1 and to 0.17 following S2O8(2-) and S2O8(2-)/H2O2 oxidation processes, respectively. The fractions of COD were determined before and after each oxidation processes (S2O8(2-) and S2O8(2-)/H2O2). The fraction of biodegradable COD(bi) increased from 36% in raw leachate to 57% and 68% after applying S2O8(2-) and S2O8(2-)/H2O2 oxidation, respectively. As for soluble COD(s), its removal efficiency was 39% and 78% following S2O8(2-) and S2O8(2-)/H2O2 oxidation, respectively. The maximum removal for particulate COD was 94% and was obtained after 120 min of S2O8(2-)/H2O2 oxidation. As a conclusion, S2O8(2-)/H2O2 oxidation could be an efficient method for improving the biodegradability of anaerobic stabilized leachate.
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Recuperação e Remediação Ambiental/métodos , Peróxido de Hidrogênio/química , Sulfatos/química , Poluentes Químicos da Água/metabolismo , Anaerobiose , Biodegradação Ambiental , Análise da Demanda Biológica de Oxigênio , OxirreduçãoRESUMO
BACKGROUND: Wastewater discharged from electroplating industry contains different concentrations of heavy metals, which when released into the environment pose a health hazard to human beings. OBJECTIVES: The aim of this study was to assess the effectiveness of orange peel as an adsorbent in the recovery of Nickel (Ni) from electroplating wastewater. MATERIALS AND METHODS: The effectiveness of orange peel as an adsorbent was assessed by determining the optimum conditions of adsorption (adsorbent dose, pH, and contact time), calculating the recovery percentage, and characterizing the orange peel sludge resulting from adsorption/desorption process as being hazardous or not. RESULTS: Under optimum conditions for adsorption, orange peel was found to be an effective adsorbent of Ni from electroplating wastewater. It achieved 59.28% removal of the metal from a solution containing 528 mg/l, at a dose of 60 g/l, at pH 7, and for 1-h contact time. The nickel uptake capacity of orange peel was calculated to be 5.2 mg/g. Using HCl for desorption of adsorbed Ni, a recovery of 44.46% of Ni discharged in the wastewater could be reached. Orange peel resulting from the adsorption/desorption process was characterized as being nonhazardous. CONCLUSION AND RECOMMENDATION: Orange peel was found to be effective in the recovery of nearly half of the amount of Ni discharged in electroplating wastewater. Further studies are required to determine (a) the impact of the recovered NiCl2 solution on the quality of the plated product, (b) the effect of activation of orange peel on the adsorption process, and (c) the number of cycles during which orange peel can be reused as an effective adsorbent.
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Citrus/química , Níquel/análise , Níquel/química , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/análise , Adsorção , Galvanoplastia , Humanos , Concentração de Íons de Hidrogênio , Poluentes Químicos da Água/químicaRESUMO
BACKGROUND: Alamein Marina Lagoon is one of six lagoons, lying on the Egyptian Mediterranean Coast. Between 1988 and 1995, a large-scale recreational compound called Alamein Marina Touristic Village was established to contain most of these lakes. The study aims to assess the quality of Alamein Marina Lagoon water in an attempt to evaluate the environmental impact of the touristic summer activities on the lake and to determine at what level this recreational lagoon stands as a healthy resort, among the other resorts around the Mediterranean Sea Basin. MATERIALS AND METHODS: Fourteen sampling stations were chosen to present the four sub-basins of the lagoon and its outlets on the Mediterranean Sea. Physical, chemical, and bacteriological characteristics of the lagoon water were determined. RESULTS: Lagoon water pH was found to range between 6.8 and 7.9. Dissolved oxygen, biochemical oxygen demand, nitrates and phosphates were 6.5 mg/L, 1 mg/L, 0.5 µg/L, and 3.8 µg/L respectively. Fecal coliform were not detected in all sampling stations. CONCLUSION: Alamein Marina water characteristics were complying with the standards set by Egyptian legislations concerning recreational water all over the study period. They were also complying with the levels set by different international organizations such as the WHO and Blue Flag. Besides, by calculating the water quality index for Alamein Marina Lagoon and its four sub-basins, water was found to be of an 'excellent' quality.
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Lagos , Qualidade da Água , Monitoramento Ambiental , Humanos , Nitratos , Recreação , Medição de Risco , Estações do AnoRESUMO
Considering the serious environmental threats facing Egypt, environmental education (EE) that provides the knowledge, skills, and motivation to take individual or collective action is needed to create a sustainable quality of life. This study was carried out aiming at measuring the level of environmental knowledge among preparatory school students in Alexandria, determining their attitudes towards some environmental concepts, and assessing the effect of EE on these knowledge and attitudes. The study sample was selected by stratified random method, and the assessment was conducted using a questionnaire. Results of the study revealed that 77% of the students had poor level of environmental knowledge and that 23% had fair level. In addition, 80% of the students were found to have negative attitude toward the environment and the remainder 20% were indifferent. Such knowledge and attitudes were positively correlated to their socio-economic levels. Following six EE sessions, an improvement in their knowledge and attitudes was observed where 69% of the students had a satisfactory level of knowledge and 88% had positive attitude toward the environment. Attitude was found to be positively correlated to their level of knowledge prior to and following the EE sessions. These results support the need for development and implementation of environmental education programs as part of the regular school curriculum.
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Drinking water from bottle-less coolers may pose some public health risks to consumers due to either chemical or microbiological contamination. This study was carried out aiming at assessing the quality of water dispensed from some public coolers in order to determine its compliance with the drinking water standards (Egyptian, EPA) and with the WHO guidelines. Twenty water coolers were selected randomly from different districts. Water samples were collected thrice from these coolers and once from the mains supplying the coolers. Results of analysis of these samples revealed that 85% of water coolers were containing <0.5 mg/l free residual chlorine, 65% were containing lead higher than 0.01mg/l, and 55% were containing magnesium hardness higher than 150 mg/l. As for the biological contamination, 15% of the coolers were contaminated with Cryptosporidium parvum, 15% were containing total coliform group of bacteria, 5 % gave positive thermotolerent coliform test and 5% gave positive Streptococcus fecalis test. The study concluded that such contamination might be from failure to thoroughly clean the coolers on a regular basis. Consequently, the study recommends proper installation of the cooler, a maintenance agreement with the cooler supplier, testing cooler water at regular intervals by the Ministry of Health representatives, and -if possible- replacing these types of coolers with those with a water purification system.
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New Borg Al-Arab city includes 9 residential areas and 4 industrial zones. The four industrial zones are occupied by 266 running factories belonging to different industrial sectors. All the domestic sewage as well as the industrial wastewater is treated at an oxidation pond treatment plant and the plant effluent is used in irrigation of silviculture areas. The plant consists of 2 pond complexes. Each complex comprises 9 facultative ponds, arranged in 3 parallel series. Raw wastewater is pre-treated through screens and grit removal before entering the primary ponds. The study aims at assessment of the performance of the waste stabilization ponds. The results revealed that pre-treatment units were not functioning properly. The retention time was calculated to be 6 days in each pond of the first complex and 3 days in each pond of the second complex. The mean BOD surface loading rate was calculated to be 676 kg/ha/d for the first complex and 1584 kg/ha/d for the second. The plant was hydraulically and organically overloaded. The percentage removal of BOD, COD, SS, and NH3-N had an annual mean of 57%, 56%, 44%, and 39%, respectively for the first complex and 21%, 42%, 39%, and 25%, respectively for the second. Faecal coliforms were reduced by about 1 log10 unit in both complexes. The final pond effluent was not complying with the Egyptian law for reuse in irrigation. The study proposed some recommendations which can improve the efficiency of the plant as well as the effluent quality.
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Resíduos Industriais , Eliminação de Resíduos Líquidos/normas , Poluentes da Água/isolamento & purificação , Poluição da Água/análise , Eficiência Organizacional , Egito , População Urbana , Eliminação de Resíduos Líquidos/métodos , Microbiologia da ÁguaRESUMO
Recently, we have reported that the isolated guanine nucleotide-binding regulatory protein, Gh, couples to the alpha 1-adrenergic receptor (Im, M.-J., and Graham, R. M. (1990) J. Biol. Chem. 265, 18944-18951 and Im, M.-J., Riek, R.P., and Graham, R. M. (1990) J. Biol. Chem. 265, 18952-18960) and has a molecular mass of approximately 74 kDa, and the approximately 50-kDa protein which is copurified probably regulates guanine nucleotide binding of the 74-kDa GTP-binding protein. In this paper, we describe the role of purified Gh in the regulation of phospholipase C in the reconstitution system. The stimulation of phospholipase C activity by Gh effectively occurred at a low calcium concentration (less than or equal to 2 microM), but the phospholipase C (PLC) itself required at least 50-100 times more calcium to become fully activated. The characteristic nature of phospholipase C stimulation by Gh is its response to the calcium concentration. Thus, the enzyme activity changes in narrow submicromolar ranges and reaches maximal stimulation, but it does not extend to the levels above those stimulated by calcium alone. The calcium concentrations for the maximal stimulation of phospholipase C activity were 10-20 microM with phospholipid vesicles and 100-200 microM with detergent solution. These calcium concentrations were further decreased when Gh and phospholipase C were co-reconstituted into the phospholipid vesicles or in the detergent solution. The maximal stimulations of the PLC activity were reached at less than 5 microM calcium in both the vesicles and the detergent solution. The changes of calcium concentration for the activation of PLC are quite different from those obtained by reconstituting PLC-beta 1 with Gq-like G-proteins (Smarcka, A. V., Hepler, J. R., Brown, K. O., and Sternweis, P. C. (1991) Science 251, 804-807 and Taylor, S. J., Chae, H. Z., Rhee, S. G., and Exton, J. H. (1991) Nature 350, 516-518). The phospholipase C activity was stimulated in a Gh concentration-dependent manner in the presence of GTP gamma S. The phospholipase C activity was activated by Gh alpha in the presence of aluminum fluoride, but not by Gh beta. Furthermore, a Gh.PLC complex can be induced by incubation with aluminum fluoride in a detergent solution and partially purified without the dissociation of related proteins. Thus, our reconstitution studies show that the pattern of stimulation of PLC by AIF-4-activated Gh in the ternary complex is similar to the stimulation of PLC activated by Gh in both detergent solution and phospholipid vesicles.