Intraoperative Use of Ultrasonography in the Reduction of Zygomatico-Maxillary Complex Fractures.

Study Design: A single blind randomized controlled study. Objective: The aim of this study is to evaluate the use of ultrasonography intraoperatively to assess the reduction of unilateral zygomatic complex fractures with a control group using the conventional blind digit palpation. Methods: The study comprised of a sample size of 24 patients with 21 male and 3 female patients. Patients of all age groups diagnosed with unilateral displaced zygomatic complex fracture with or without mandible fracture were included in the study. The subjects were randomized into study and control groups based on a standard protocol with a total of 24 patients. Imaging was in the form of a preoperative and postoperative 3D computed tomography scan with reconstruction of the maxilla and mandible to interpret the diagnosis for all subjects. The inter-fracture distance of the fractured infraorbital rim were measured in 3 dimensions (antero-posterior, medio-lateral and supero-inferior) and compared pre and postoperatively. Preoperative, intraoperative and postoperative ultrasonographic examination was performed and recorded on all patients at the frontozygomatic region, infraorbital rim and zygomatic buttress to assess the proximity of the fractured margins pre reduction, post reduction and post fixation of the fracture segments. Result: Statistical analytic results were significant in all 3 dimensions when measured postoperatively using computed tomography. Conclusion: Ultrasonography is an effective screening and intraoperative tool in the armamentarium of oral and maxillofacial surgery to assess zygomatic complex fractures, avoiding incisions in aesthetic areas of the maxillofacial region.

Indian Guidelines on Nebulization Therapy.

Inhalational therapy, today, happens to be the mainstay of treatment in obstructive airway diseases (OADs), such as asthma, chronic obstructive pulmonary disease (COPD), and is also in the present, used in a variety of other pulmonary and even non-pulmonary disorders. Hand-held inhalation devices may often be difficult to use, particularly for children, elderly, debilitated or distressed patients. Nebulization therapy emerges as a good option in these cases besides being useful in the home care, emergency room and critical care settings. With so many advancements taking place in nebulizer technology; availability of a plethora of drug formulations for its use, and the widening scope of this therapy; medical practitioners, respiratory therapists, and other health care personnel face the challenge of choosing appropriate inhalation devices and drug formulations, besides their rational application and use in different clinical situations. Adequate maintenance of nebulizer equipment including their disinfection and storage are the other relevant issues requiring guidance. Injudicious and improper use of nebulizers and their poor maintenance can sometimes lead to serious health hazards, nosocomial infections, transmission of infection, and other adverse outcomes. Thus, it is imperative to have a proper national guideline on nebulization practices to bridge the knowledge gaps amongst various health care personnel involved in this practice. It will also serve as an educational and scientific resource for healthcare professionals, as well as promote future research by identifying neglected and ignored areas in this field. Such comprehensive guidelines on this subject have not been available in the country and the only available proper international guidelines were released in 1997 which have not been updated for a noticeably long period of over two decades, though many changes and advancements have taken place in this technology in the recent past. Much of nebulization practices in the present may not be evidence-based and even some of these, the way they are currently used, may be ineffective or even harmful. Recognizing the knowledge deficit and paucity of guidelines on the usage of nebulizers in various settings such as inpatient, out-patient, emergency room, critical care, and domiciliary use in India in a wide variety of indications to standardize nebulization practices and to address many other related issues; National College of Chest Physicians (India), commissioned a National task force consisting of eminent experts in the field of Pulmonary Medicine from different backgrounds and different parts of the country to review the available evidence from the medical literature on the scientific principles and clinical practices of nebulization therapy and to formulate evidence-based guidelines on it. The guideline is based on all possible literature that could be explored with the best available evidence and incorporating expert opinions. To support the guideline with high-quality evidence, a systematic search of the electronic databases was performed to identify the relevant studies, position papers, consensus reports, and recommendations published. Rating of the level of the quality of evidence and the strength of recommendation was done using the GRADE system. Six topics were identified, each given to one group of experts comprising of advisors, chairpersons, convenor and members, and such six groups (A-F) were formed and the consensus recommendations of each group was included as a section in the guidelines (Sections I to VI). The topics included were: A. Introduction, basic principles and technical aspects of nebulization, types of equipment, their choice, use, and maintenance B. Nebulization therapy in obstructive airway diseases C. Nebulization therapy in the intensive care unit D. Use of various drugs (other than bronchodilators and inhaled corticosteroids) by nebulized route and miscellaneous uses of nebulization therapy E. Domiciliary/Home/Maintenance nebulization therapy; public & health care workers education, and F. Nebulization therapy in COVID-19 pandemic and in patients of other contagious viral respiratory infections (included later considering the crisis created due to COVID-19 pandemic). Various issues in different sections have been discussed in the form of questions, followed by point-wise evidence statements based on the existing knowledge, and recommendations have been formulated.

Association of Human Papilloma Virus in Oral Squamous Cell Carcinoma: An Alarming Need for Human Papillomavirus 16 Screening in Cancer Patients.

BACKGROUND: The percentage of cancers of the tongue and palatine tonsils has continued to increase by 2%-4% among younger men. This increased prevalence of a subsection of oropharyngeal carcinoma can be associated with human papillomavirus (HPV). Among the head-and-neck cancers, a strong association with HPV infection is evident with oropharyngeal cancers, particularly tonsillar and basal tongue cancers. OBJECTIVES: Oral carcinoma, with an overall incidence of 16.1 adults per 100,000, is one of the leading malignancies worldwide, presenting a noticeable geographic variation in its distribution. Squamous cell carcinoma (SCC) being the most common of all oral malignancies, the objective of the study is to detect the HPV antigen p16 over-expression in patients with oral SCC using immunohistochemistry (IHC). MATERIALS AND METHODS: Oral SCC (OSCC) diagnosed formalin-fixed-paraffin embedded blocks were processed for IHC. RESULTS: Out of 50 cases, 3 were deferred due to insufficient tumor sample and 2/47 cases were p16 positive and the site was the lateral border of the tongue. CONCLUSION: The HPV antigen overexpression in patients with OSCC was investigated to detect the incidence of HPV in SCC of oral cavity. P16 was used as a marker for the detection of OSCC using IHC in HPV-induced OSCC. Positives were detected thus concluding the significance of studying HPV expression during diagnosis.

Pleomorphic Sarcoma of the Oral Cavity: A Rare Case Entity.

Pleomorphic sarcomas are extremely rare in the oral cavity, representing only 5% of all soft tissue sarcomas in the extremities of adults. They form a group of highly undifferentiated pleomorphic malignant tumors. A 36-year-old male reported to the OP with a chief complaint of a tooth ache in the right lower quadrant for the past 6 months. The patient gave a history of extraction of a mobile tooth in that region. A radiograph of the region was advised. An incisional biopsy was also done and sent for histopathological examination. The microscopy revealed the presence of spindle-shaped cells showing dysplastic features. A panel of immunohistochemical markers were performed to identify the tissue of origin of the lesion. The article details the clinical, radiographic, and microscopic features of a pleomorphic soft tissue lesion along with the array of immunohistochemical markers, leading to the final diagnosis of such enigmatic lesions.

Intraoperative Management of Recurrent Leukoplakia at Red Zone.

Oral leukoplakia (OL) is a potentially malignant oral disorder (PMOD) that sometimes trans-form into oral squamous cell carcinoma (OSCC). OL is one of the most frequent PMODs seen in the oral cavity. The global prevalence of OL is approximately 2.6%, with its worst prognosis of undergoing a malignant transformation. Leukoplakia is clinically divided into red zones (tongue and floor of mouth) and nonred zones (buccal mucosa, palate, and soft palate) areas. The red zone areas have more potency of transforming into malignancy. Hence, patients with red zone areas need to be followed up more frequently and treated appropriately. This case report signifies the importance of treating one such case of leukoplakia at red zone area.

Reliability of Modified Hertels Exophthalmometer as an Intraoperative Tool for Assessment of Relative Globe Position in Orbital/Zygomatic Fracture.

INTRODUCTION: Axial globe position assessment is commonly carried out with Hertels Exophthalmometer. Hertels requires an intact lateral orbital rim for its placement, which is often fractured in zygomatic fractures. Hence, to overcome this problem, we have modified the instrument for its application in zygomatic/orbital fractures. Reliability of this Modified Hertels Exopthalmometer has been already validated in normal healthy patients. Therefore, the aim of this study is to assess the efficacy of the Modified Hertels Exophthalmometer in pateints with zygomatic/orbital fracture. MATERIALS AND METHODS: This is a prospective study carried out between April 2015 and October 2017, including 20 patients with a mean age of 34 years. Enophthalmos was measured using Modified Hertels in patients with unilateral orbital/zygomatic fracture indicated for surgical intervention by a single observer. The data was collected and statistically analyzed. Paired sample t-test was done to compare the preoperative exophthalmometer reading with readings at different time points. RESULTS: A statistically significant difference was noted (P = 0.031) among the variables of Modified Hertels. We believe this instrument to be of practical use in the assessment of enophthalmos/exophthalmos in patients with lateral orbital trauma, surgery or disease and also precludes the use of rim-based exophthalmometry and other modifications of same.

CpG-ODNs induces up-regulated expression of chemokine CCL9 in mouse macrophages and microglia.

Unmethylated CpG oligodeoxynucleotides (CpG-ODNs) interact with Toll-like receptor (TLR) 9 to activate macrophage/microglia in central nervous system (CNS). Here, we investigated the potential involvement of the chemokine CCL9 and its receptor CCR1 in the effects of CpG-ODNs on macrophage/microglial cells. CpG-ODNs enhanced the expression of TLR9 mRNA of RAW264.7 macrophage and BV2 microglia cells time dependently. The expression of CCL9 of macrophages/microglia showed different responsiveness upon stimulation with a variety of CpG-ODN sequences. The CpG-ODNs-mediated induction of CCL9 was TLR9/MyD88 dependent and associated with activation of stress kinases, particularly ERK, p38 MAPK and PI3K. The expression of CCR1 was also significantly increased by CpG-ODNs that increased CCL9 expression. These results reveal the potential involvement of CCL9 and CCR1 in regulation of macrophage and microglial cells by CpG-ODNs and may help improving our understanding about the role of the chemokine/chemokine receptor pairs in macrophage/microglia under physiologic and pathologic conditions.

Optical recording of intracellular pH in respiratory chemoreceptors.

We studied the spontaneously active in vitro tadpole brainstem and recorded whole nerve respiratory activity while simultaneously visualizing intracellular pH (pHi) dynamics using the pH-sensitive dye, 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, acetoxymethyl ester (BCECF, AM). The isolated, superfused tadpole brainstem is well oxygenated and retains synaptic connectivity among respiratory central pattern generators, central respiratory chemoreceptors, and respiratory motor neurons. We generated a calibration curve to correlate the emitted fluorescence of BCECF to pHi. In addition, we demonstrated that the dye loading protocol that we established labeled an adequate number of cells and did not disrupt spontaneous respiratory rhythmogenesis or the respiratory response to central chemoreceptor stimulation. Validation of the use of the pH sensitive dye BCECF in this preparation will permit further characterization of the pH regulatory responses of central respiratory chemoreceptors and allow correlation between the changes in pHi in central chemoreceptors and respiratory motor output recorded from cranial nerves.

Serotonergic modulation of respiratory rhythmogenesis and central chemoreception.

In addition to evidence supporting serotonergic modulation of respiratory rhythmogenesis, serotonergic mechanisms play a role in central respiratory chemoreception. We examined the role of serotonin 5HT1A receptors in respiratory rhythmicity and central respiratory chemosensitivity in in vitro brainstem preparations of the bullfrog tadpole, Rana catesbeiana. Spontaneous respiratory motor output was recorded from cranial nerve 7 at control bath pH (7.8) and hypercapnic bath pH (7.4) as bath concentrations of a 5HT1A receptor agonist were steadily increased from 0.5 to 25 microM. Activation of the 5HT1A receptor significantly altered the respiratory burst cycle. Significant increases in both gill and lung burst cycle were observed in response to bath application of 8-OH-DPAT; gill burst cycle in response to 8-OH-DPAT was influenced by bath pH, as gill burst cycle at bath pH 7.8 was not significantly increased at 0.5 or 5.0 microM 8-OH-DPAT. However, when the pH was reduced to 7.4 gill burst cycle was significantly increased at these same bath concentrations of 8-OH-DPAT. Gill burst amplitude was not altered in response to bath application of 8-OH-DPAT; however, lung burst amplitude was significantly decreased at 25.0 microM 8-OH-DPAT at bath pH 7.8. These data indicate that 5HT1A receptors are involved in neural respiratory rhythmogenic and chemoreceptive circuits in the bullfrog tadpole, and support the hypothesis that abnormalities in serotonergic systems may be an underlying component of Sudden Infant Death Syndrome.

Nasobronchial allergy and pulmonary function abnormalities among coir workers of Alappuzha.

BACKGROUND: Coir is a commercially important natural fiber obtained from the coconut husk. Coir can be woven into strong twine or rope, and is used for padding mattresses, upholstery, etc. Coir industry provides a major share of occupation to the natives of Alappuzha district of Kerala State. It has been noticed earlier that there is increased incidence of nasobronchial allergy among the population involved in this industry. OBJECTIVES: This study was aimed at recognizing the symptomatology and pulmonary functional impairment among symptomatic coir workers. DESIGN: All coir workers who attended our institute over a period of three years were included in the study. Detailed occupational history was taken; symptom profile was studied in detail, clinical examination and pulmonary function tests conducted. RESULTS: Among the 624 symptomatic coir workers selected for this purpose, 64 patients had purely nasal symptoms, while 560 had symptoms of nasobronchial allergy. 357 patients had reversible obstruction on PFT, while 121 had only small airway obstruction. CONCLUSIONS: We conclude that coir work induced nasobronchial allergy and pulmonary function abnormalities. In absence of CT scan and bronchial challenge testing it may be inappropriate to label coir work as occupational hazard. However the present study may be used as thought provoking study to initiate further understanding.

A Prospective, Randomized Double-Blinded Study to Evaluate the Efficacy of Buffered Local Anesthetics in Infected and Inflamed Pulp and Periapical Tissues.

AIM: The aim of this study is to evaluate the efficacy of sodium bicarbonate as an additive alkalizing agent to local anesthetic solutions in inflamed and infected pulpal and periapical tissues. TYPE OF STUDY: A prospective, randomized crossover double-blinded study was carried out in a university-affiliated hospital in Chennai. MATERIALS AND METHODS: A randomized crossover double-blinded study was designed wherein ninety-six patients were enrolled for the study. 1.8 ml of 2% lignocaine with 1:200,000 adrenaline was administered. The latency time period was found to be 5-10 min and extraction was attempted. During extraction, if the patient experienced pain, 0.5 ml of 8.4% sodium bicarbonate was injected into the previously injected local anesthesia site. A time period of 3 min was allowed for the alkalinization to occur. Extraction was carried out only when the patient did not complain of pain. Pain score was assessed before and after administration of 8.4% sodium bicarbonate using visual analog scale. Pulse rate at the baseline, before and after administration of 8.4% sodium bicarbonate, was recorded and the pain scale values were correlated with pulse rate. RESULTS: It was found that there was a significant decrease in pain after injecting buffered local anesthetics (p < 0.1). Pain score before injecting sodium bicarbonate was higher when compared to post-injection of sodium bicarbonate. There was also significant reduction in pulse rate following the administration of sodium bicarbonate. CONCLUSION: Buffered 2% lignocaine with 1:200,000 epinephrine had early onset of anesthesia when compared to unbuffered form. Injecting 2% buffered lignocaine pain was significantly reduced during extraction in the teeth.

Effect of 5-azacytidine on the methylation aspects of NMDA receptor NR2B gene in the cultured cortical neurons of mice.

Our previous study revealed that the exposure of the drug 5-Azacytidine and ethanol to the cultured cortical neurons of mice causes demethylation of cytosine residues in the CpG island of the NMDA receptor NR2B gene (Marutha Ravindran and Ticku, Mol Brain Res 121:19-27, 2004). In the present study, we further analyzed methylation in the CpG island with various concentration frame and time frame of exposure of the cultured cortical neurons with 5-azacytidine to identify whether methylation in the NR2B gene is site specific or region specific. Methylation was studied by digesting the genomic DNA with methylation sensitive HpaII, MspI, AciI or HhaI enzyme following the exposure of cultured cortical neurons of mice with 5-azacytidine by performing PCR and Southern hybridization. We observed demethylation of DNA at 1, 3 and 5 muM concentrations of 5-azacytidine in the regions (5982-6155), (6743-7466) and at 3 and 5 muM concentrations of 5-azacytidine used in the region (6477-6763). Similarly in the time frame study with 5-azacytidine, demethylation of DNA was observed at 24 h and 36 h of incubation with 5-azacytidine in the regions (5982-6155), (6743-7466) and at 36 h of incubation with 5-azacytidine used in the region (6477-6763). Our experimental results demonstrate that the methylation in the CpG islands of the NR2B gene may not be site specific or region specific in the cultured cortical neurons of mice.

Comparision of Vital Surgical Parameters, after Administration of Midazolam and Dexmedetomidine for Conscious Sedation in Minor Oral Surgery.

AIM: The aim of this study is to compare the efficacy between midazolam and dexmedetomidine in relation to vital parameters, sedation score, pain score, cognitive judgment, and postoperative amnesia to the event in conscious sedation for minor oral surgical procedure. MATERIALS AND METHODS: A sample size of 30 patients were selected in each group: Group M (midazolam) and Group D (dexmedetomidine). RESULTS: The mean heart rate (HR) and systolic and diastolic blood pressure measurements were significantly higher in Group M after the 20th min when compared to Group D. The visual analog scale (VAS) scores of pain were not statistically significant between the two groups during the procedure, but at the time of discharge, statistically significant VAS scores were found between the two groups. Nine (30%) patients in Group D and 21 (70%) patients in Group M showed cognitive judgment impairment with the Stroop Color and Word Test at the 30th min. CONCLUSION: The dexmedetomidine group of patients had reduced blood pressure and HR. No significant differences were noted in oxygen saturation or in respiratory rate between the two drugs. Patients had better sedation, analgesia, lesser cognitive impairment, and amnesia in the dexmedetomidine group.

Maxillofacial intervention in trauma patients aged 60 years and older.

The purpose of this study was to evaluate the incidence of trauma victims of age 60 years and older who required maxillofacial intervention. The study analyses the pattern of injuries and the various factors that predict the treatment plan of these patients. A retrospective study was carried out in 1820 trauma patients who reported to the Sri. Ramachandra Dental College and Hospital and required maxillofacial intervention, over a period of 5 years (October 2000 and September 2005). Of the total trauma victims, 185 patients were found to be aged 60 years more. In the majority of the patients, the injury was due to road traffic accidents (79.4%). Males (72.4%) sustained more injuries than females (27.6%). Soft tissue injuries were seen in 49.1% of the patients, while 14% had mandibular fractures. People in their early 60s were injured more often than their older counterparts. The findings of this study highlight the present situation with regard to maxillofacial trauma in patients aged 60 years and older and its management in this part of the country.

Intra-alveolar extraction of impacted distoangular mandibular third molars: A novel technique.

Recent trends in maxillofacial surgery are to reduce the trauma to the adjacent soft tissue. The distoangular impaction presents a challenge to the maxillofacial surgeon and also results in more surgical morbidity. Here, we present a minimally invasive extraction technique for the distoangular mandibular third molar impaction.

Evaluation of the Role Played by Cyclin D1 as a Diagnostic and Prognostic Marker in the Progression of Oral Carcinogenesis.

ABSTRACT: Cyclin D1 is linked with the development and progression of oral squamous cell carcinoma (OSCC). This case-control study was directed to characterise the immunoreactivity of the protein cyclin D1 and its correlation with the clinicopathological parameters of patients with OSCC and potentially malignant disorders (PMD). A group of patients with OSCC were followed up after treatment, and the cyclin D1 expression was reviewed for correlation of cyclin D1 expression with prognosis of the patients. METHODOLOGY: Sixty individuals were included in this study: OSCC (20), PMD (20) and Control (20). Immunohistochemistry assay was evaluated. The clinicopathological parameters were correlated with the staining intensity of cyclin D1. The results were subjected to Pearson's correlation test. RESULTS: Age, gender and site showed no statistically significant correlation with cyclin D1 expression in OSCC and PMD. The cyclin D1 score did not show a significant difference with histopathological diagnosis of OSCC. Cyclin D1 was not expressed in 60% of the Control and 30% PMD cases while the expression of cyclin D1 was seen in 100% of OSCC cases although cyclin D1 score did not show a statistically significant association in the prognosis of the disease among the OSCC patients.

Chromosome segment duplications in Neurospora crassa and their effects on repeat-induced point mutation and meiotic silencing by unpaired DNA.

The size and extent of four Neurospora crassa duplications, Dp(AR17), Dp(IBj5), Dp(OY329), and Dp(B362i), was determined by testing the coverage of RFLP markers. The first three duplications were all > approximately 350 kb and have been shown in earlier studies to act as dominant suppressors of repeat-induced point mutation (RIP) in gene-sized duplications, possibly via titration of the RIP machinery. Dp(B362i), which is only approximately 117 kb long, failed to suppress RIP. RIP suppression in gene-sized duplications by large duplications was demonstrated using another test gene, dow, and supposedly applies generally. Crosses homozygous for Dp(AR17) or Dp(IBj5) were as barren as heterozygous crosses. Barrenness of the heterozygous but not the homozygous crosses was suppressible by Sad-1, a semidominant suppressor of RNAi-dependent meiotic silencing by unpaired DNA. A model is proposed in which large duplications recessively suppress semidominant Sad-1 mutations. The wild-isolated Sugartown strain is hypothesized to contain a duplication that confers not only dominant suppression of RIP but also a barren phenotype, which is linked (9%) to supercontig 7.118 in LG VII.

Low concentrations of ethanol do not affect radioligand binding to the delta-subunit-containing GABAA receptors in the rat brain.

In the present study, we investigated the co-localization pattern of the delta subunit with other subunits of GABA(A) receptors in the rat brain using immunoprecipitation and Western blotting techniques. Furthermore, we investigated whether low concentrations of ethanol affect the delta-subunit-containing GABA(A) receptor assemblies in the rat brain using radioligand binding to the rat brain membrane homogenates as well as to the immunoprecipitated receptor assemblies. Our results revealed that delta subunit is not co-localized with gamma(2) subunit but it is associated with the alpha(1), alpha(4) or alpha(6), beta(2) and/or beta(3) subunit(s) of GABA(A) receptors in the rat brain. Ethanol (1-50 mM) neither affected [(3)H]muscimol (3 nM) binding nor diazepam-insensitive [(3)H]Ro 15-4513 (2 nM) binding in the rat cerebellum and cerebral cortex membranes. However, a higher concentration of ethanol (500 mM) inhibited the binding of these radioligands to the GABA(A) receptors partially in the rat cerebellum and cerebral cortex. Similarly, ethanol (up to 50 mM) did not affect [(3)H]muscimol (15 nM) binding to the immunoprecipitated delta-subunit-containing GABA(A) receptor assemblies in the rat cerebellum and hippocampus but it inhibited the binding partially at a higher concentration (500 mM). These results suggest that the native delta-subunit-containing GABA(A) receptors do not play a major role in the pharmacology of clinically relevant low concentrations of ethanol.

Effect of chronic administration of ethanol on the regulation of the delta-subunit of GABA(A) receptors in the rat brain.

In the present study, we investigated the effect of chronic ethanol (CE) administration on the polypeptide levels of the delta-subunit of GABA(A) receptors and [(3)H]muscimol binding to the immunoprecipitated delta-subunit-containing GABA(A) receptor assemblies in the rat brain. CE administration resulted a down-regulation of polypeptide levels of the delta-subunit of GABA(A) receptors in the rat cerebellum and hippocampus, whereas there were no changes in the delta-subunit polypeptide levels in the rat cerebral cortex. Further, CE administration caused a down-regulation of native delta-subunit-containing GABA(A) receptor assemblies in the rat cerebellum as determined by [(3)H]muscimol binding to the immunoprecipitated receptor assemblies. These results indicate that the delta-subunit-containing GABA(A) receptors may play a role in chronic ethanol-induced tolerance and dependence.

Generation of various amino acids mutants in the trpR gene of Escherichia coli by site-directed mutagenesis.

Tryptophan repressor (trpR) gene lacks various amino acid codons. To establish these codons in the trpR gene, we created the mutants by site-directed mutagenesis in the trpR gene of pHK1 plasmid. The interested regions of trpR gene were amplified, cloned in pT7-5 plasmid and transformed in to the cells harboring pGP1-2 plasmid. These plasmid products were labeled with (35)S Met, and following sequencing we observed the presence of mutants for cysteine, glycine, serine and lysine in the trpR gene of E. coli. Therefore, using these approach mutants in various genes of E. coli could be established and used as a tool to study translational bypassing in trpR gene of E. coli.