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Varughese BT, Manoj D, Arakkal AL, Johnson LR, James RI. Mock court: a valuable tool to teach legal procedures to undergraduate medical students. Int J Legal Med 2024:10.1007/s00414-024-03226-y. [PMID: 38594501 DOI: 10.1007/s00414-024-03226-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 03/22/2024] [Indexed: 04/11/2024]
Abstract
BACKGROUND Teaching through role-plays is a preferred modality when certain behaviours or skills need to be taught. They provide a risk-free environment that simulates a real-life scenario. For a clinician, appearance in a Court of Law as an expert witness is a part of his/her legal obligation. OBJECTIVE To explore the utility of Mock Court as an additional teaching tool for undergraduate medical students, in understanding and familiarizing with legal procedures, specifically the courtroom procedures. METHODOLOGY We conducted Mock Court sessions with the students playing various roles, following which feedback was collected from the students, teachers and guest assessors. The data was statistically analysed by comparison of frequencies and paired t-test (pre- and post-session comparison). RESULTS The study revealed a positive effect of the Mock Court sessions on the students, based on their increased confidence, motivation and a better grasp of legal procedures. There was a statistically significant (p < 0.001) improvement in the understanding of specific aspects of courtroom procedures after the session. CONCLUSION The authors recommend the active implementation of Mock Court as a teaching aid for undergraduate medical students, and the use of PDSA (Deming) cycle as a tool for quality-checks and self-improvement in subsequent sessions.
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Affiliation(s)
- Benjy Tom Varughese
- Department of Forensic Medicine & Toxicology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Daniel Manoj
- Department of Forensic Medicine & Toxicology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Antony L Arakkal
- Department of Forensic Medicine & Toxicology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Latif Rajesh Johnson
- Department of Forensic Medicine & Toxicology, Christian Medical College, Vellore, Tamil Nadu, India.
| | - Ranjit Immanuel James
- Department of Forensic Medicine & Toxicology, Christian Medical College, Vellore, Tamil Nadu, India
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James RI, Khandekar I. Doctors, FIRs, and Arrest in Alleged Medical Negligence Cases in India: Demystifying the Legal Tenability. J Assoc Physicians India 2024; 72:87-92. [PMID: 38736124 DOI: 10.59556/japi.72.0481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2024]
Abstract
The relationship between a doctor and a patient is a contract, retaining the essential elements of the tort. Modern medical practice has evolved alongside the court of law to regulate the conduct of doctors and hospitals to reduce litigations of medical negligence. Lately, Indian patients have become more aware of their rights and the Consumer Protection Act. This awareness encourages patients to litigate and seek the help of redressal forums to mitigate their loss/injury in cases of medical negligence. Though there is a rise in complaints of medical negligence filed against doctors and hospitals, these allegations are often frivolous. The specter of litigation constantly looms over medical practitioners, who frequently struggle to defend themselves in a court of law, causing undue anxiety and anguish. Thus, a doctor can be considered the second victim in a medical negligence case. Lack of awareness regarding their legal rights and pertinent laws coupled with contradictory actions of the law enforcement agencies while handling alleged medical negligence cases worsens a doctor's trepidation. Hence, this article attempts to raise awareness among medical professionals, which will thereby allay undue fear while facing an allegation.
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Affiliation(s)
- Ranjit Immanuel James
- Associate Professor, Department of Forensic Medicine and Toxicology, Christian Medical College, Vellore, Tamil Nadu, India, Corresponding Author
| | - Indrajit Khandekar
- Professor, Department of Forensic Medicine and Toxicology, Mahatma Gandhi Institute of Medical Sciences, Sevagram, Maharashtra, India
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James RI, Verma R, Johnson LR, Manesh A, Jayakumar J, Sen M, Joseph J, Kumarasami R, Mitra PP, Sivaprakasam M, Varghese GM. A Standardized Protocol for the Safe Retrieval of Infectious Postmortem Human Brain for Studying Whole-Brain Pathology. Am J Forensic Med Pathol 2023; 44:303-310. [PMID: 37490584 PMCID: PMC10662599 DOI: 10.1097/paf.0000000000000871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
ABSTRACT We describe a safe and standardized perfusion protocol for studying brain pathology in high-risk autopsies using a custom-designed low-cost infection containment chamber and high-resolution histology. The output quality was studied using the histological data from the whole cerebellum and brain stem processed using a high-resolution cryohistology pipeline at 0.5 μm per pixel, in-plane resolution with serial sections at 20-μm thickness. To understand the pathophysiology of highly infectious diseases, it is necessary to have a safe and cost-effective method of performing high-risk autopsies and a standardized perfusion protocol for preparing high-quality tissues. Using the low-cost infection containment chamber, we detail the cranial autopsy protocol and ex situ perfusion-fixation of 4 highly infectious adult human brains. The digitized high-resolution histology images of the Nissl-stained series reveal that most of the sections were free of processing artifacts, such as fixation damage, freezing artifacts, and osmotic shock, at the macrocellular and microcellular level. The quality of our protocol was also tested with the highly sensitive immunohistochemistry staining for specific protein markers. Our protocol provides a safe and effective method in high-risk autopsies that allows for the evaluation of pathogen-host interaction, the underlying pathophysiology, and the extent of the infection across the whole brain at microscopic resolutions.
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Affiliation(s)
- Ranjit Immanuel James
- From the Department of Forensic Medicine and Toxicology, Christian Medical College, Vellore
| | - Richa Verma
- Sudha Gopalakrishnan Brain Centre, Indian Institute of Technology Madras, Chennai
| | - Latif Rajesh Johnson
- From the Department of Forensic Medicine and Toxicology, Christian Medical College, Vellore
| | - Abi Manesh
- Department of Infectious Diseases, Christian Medical College, Vellore
| | - Jaikishan Jayakumar
- Sudha Gopalakrishnan Brain Centre, Indian Institute of Technology Madras, Chennai
- Center for Computational Brain Research
| | - Mousumi Sen
- From the Department of Forensic Medicine and Toxicology, Christian Medical College, Vellore
| | - Jayaraj Joseph
- Sudha Gopalakrishnan Brain Centre, Indian Institute of Technology Madras, Chennai
- Department of Electrical Engineering
- Healthcare Technology Innovation Centre, Indian Institute of Technology Madras, Chennai, India
| | - Ramdayalan Kumarasami
- Sudha Gopalakrishnan Brain Centre, Indian Institute of Technology Madras, Chennai
- Healthcare Technology Innovation Centre, Indian Institute of Technology Madras, Chennai, India
| | - Partha P. Mitra
- Center for Computational Brain Research
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY
| | - Mohanasankar Sivaprakasam
- Sudha Gopalakrishnan Brain Centre, Indian Institute of Technology Madras, Chennai
- Department of Electrical Engineering
- Healthcare Technology Innovation Centre, Indian Institute of Technology Madras, Chennai, India
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Sasidharan BK, James RI, Sathyendra S, Harsh R, Jeba Sundararaj J, Ravindran V, T HMT, Ashok N, Thirunavukkarasu MM, Punitha JV, George TK, Isaac BTJ, Zechariah AJ, David SNJ, Yesupatham DP, Irodi A, Aruldas V, Keshava SN, Zachariah A, Kang G, Mammen JJ. UDHAVI Community Support During India's Second COVID-19 Wave: A Descriptive Study on a Tertiary Care Center's Pandemic Response Helpline. Glob Health Sci Pract 2023; 11:e2200315. [PMID: 37903577 PMCID: PMC10615235 DOI: 10.9745/ghsp-d-22-00315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 09/26/2023] [Indexed: 11/01/2023]
Abstract
BACKGROUND In April 2021, during the peak of the second wave of the COVID-19 pandemic in India, hospitals overflowed with COVID-19 patients, and people hesitated to seek necessary care due to fear of contracting the disease. The UDHAVI helpline was set up by a tertiary care hospital in Vellore with the help of district administration, nongovernmental organizations, and various supporting agencies to provide general information, medical advice, counseling, and logistics support to the community. METHODS This is a retrospective study of all the phone calls made to the UDHAVI helpline between mid-May and mid-June 2021 during the second wave of the COVID-19 pandemic. The calls were electronically captured as part of the process, and the information was subsequently retrieved and analyzed. RESULTS In all, 677 calls were received. The lines for general information, medical advice, counseling, and logistics support received 168 (25%), 377 (56%), 15 (2%), and 117 (17%) calls, respectively. Home care kits, oxygen concentrators, and food were delivered by volunteers from local nongovernmental organizations and hospitals. CONCLUSION We believe the details of our experience would be useful in the preparedness and mobilization of resources in the event of any public health emergency. As a result of this initiative, we propose an integrated partnership model for emergency response to any pandemic situation.
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Affiliation(s)
| | - Ranjit Immanuel James
- Department of Forensic Medicine and Toxicology, Christian Medical College Vellore, Vellore, India
| | - Sowmya Sathyendra
- Department of General Medicine, Christian Medical College Vellore, Vellore, India.
| | - R Harsh
- Department of Rural Unit for Health and Social Affairs, Christian Medical College Vellore, Vellore, India
| | | | - Vinitha Ravindran
- Department of Paediatric Nursing, College of Nursing, Christian Medical College Vellore, Vellore, India
| | - Hannah Mary Thomas T
- Department of Radiation Oncology, Christian Medical College Vellore, Vellore, India
| | | | | | - John Victor Punitha
- Department of General Medicine, Christian Medical College Vellore, Vellore, India
| | - Tarun K George
- Department of General Medicine, Christian Medical College Vellore, Vellore, India
| | | | | | - Samuel N J David
- Department of Hospital Management Studies and Staff Training and Development, Christian Medical College Vellore, Vellore, India
| | | | - Aparna Irodi
- Department of Radiodiagnosis, Christian Medical College Vellore, Vellore, India
| | - Vijay Aruldas
- OPD Services and Department of Medical Records, Christian Medical College Vellore, Vellore, India
| | | | - Anand Zachariah
- Department of General Medicine, Christian Medical College Vellore, Vellore, India
| | - Gagandeep Kang
- The Wellcome Trust Research Laboratory, Division of Gastrointestinal Sciences, Christian Medical College Vellore, Vellore, India
| | - Joy John Mammen
- Department of Transfusion Medicine, Christian Medical College Vellore, Vellore, India
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Murugesan M, Manoj D, Johnson LR, James RI. Forensic Microbiology in India: A missing piece in the puzzle of criminal investigation system. Indian J Med Microbiol 2023; 44:100367. [PMID: 37356836 DOI: 10.1016/j.ijmmb.2023.100367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 02/26/2023] [Accepted: 03/31/2023] [Indexed: 06/27/2023]
Abstract
BACKGROUND Forensic Microbiology is an emerging branch of science that has great potential to assist criminal investigations. Having said that, microbial analysis is not performed routinely during forensic investigations in India. This could be attributed to lack of specific training and lack of evidence-based standard protocol. OBJECTIVES The authors attempt to highlight the key areas in forensic microbiology that need to be explored in a developing nation like India. CONTENT Forensic microbiology could help in linking a person to a crime, determining the cause of death, estimating postmortem interval (PMI), etc. Additionally, applications are being developed by forensic microbiologists across the globe to investigate the coordinated and dynamic changes in microbial activity which occur after the death of a human host. Such evidence from the human postmortem microbiome can aid in criminal investigations and administration of justice. These recent advances and developments have the potential to transform the field of forensic microbiology in a developing country.
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Affiliation(s)
- Malathi Murugesan
- Department of Infectious Diseases & Hospital Infection Control Officer, Meenakshi Mission Hospital & Research Centre, Madurai, Tamil Nadu - 625107, India.
| | - Daniel Manoj
- Department of Forensic Medicine & Toxicology, Christian Medical College Vellore, Tamil Nadu - 632004, India.
| | - Latif Rajesh Johnson
- Department of Forensic Medicine & Toxicology, Christian Medical College Vellore, Tamil Nadu - 632004, India.
| | - Ranjit Immanuel James
- Department of Forensic Medicine & Toxicology, Christian Medical College Vellore, Tamil Nadu - 632004, India.
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Prabhakar Abhilash KP, James RI, Paul HE, Murugesan M, Abraham DT, Christopher J, Valsan A, Mammen JJ, Rupali P, Jesudoss I, Selvan S, Mathews P, Peter JV. Effectiveness of a monitored home isolation program for COVID-19 infection during the second wave of the pandemic. Med J Armed Forces India 2022:S0377-1237(22)00119-8. [PMID: 36068859 PMCID: PMC9437766 DOI: 10.1016/j.mjafi.2022.06.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 06/28/2022] [Indexed: 11/16/2022] Open
Abstract
Background The rapidity of spread of COVID-19 infection during the second wave of the pandemic placed tremendous stress on healthcare resources. This study evaluated the effectiveness of a monitored home isolation (HI) program. Methods In this descriptive longitudinal study, symptomatic patients were screened in the HI clinic and eligible patients were followed up at home using tele-consultation, until recovery or hospitalization. HI failure was defined as need for hospitalization. Factors associated with HI failure were assessed using logistic regression analysis and expressed as odds ratio (OR) with 95% confidence interval (CI). Results During April and May 2021, 1957 RT-PCR confirmed patients (984 male) with mean (SD) age 40 (13.5) years were enrolled; 93.3% (n = 1825) were successfully managed at home. Of the 132 patients (6.7%) who failed HI, 57 (43.2%) required oxygen therapy and 23 needed intensive care admissions. Overall mortality was 0.4% (7/1957). On adjusted analysis, factors associated with HI failure were age ≥60 years (OR 2.24; 95%CI 1.26-3.99), male gender (OR 2.26; 95%CI 1.44-3.57), subjective reporting of breathing difficulty (OR 3.64; 95%CI 2.08-6.37), history of cough (OR 2.08; 95%CI 1.37-3.17), and higher heart rate (OR 1.04; 95%CI 1.02-1.05). Although patient status (non-healthcare workers), no prior vaccination and ≥2 comorbidities were associated with HI failure on unadjusted analysis, these were non-significant on adjusted analysis. Conclusion Monitored HI program can be used successfully during a pandemic wave to judicially use scare hospital resources. Older male patients presenting with breathlessness or cough may warrant closer monitoring.
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Affiliation(s)
| | - Ranjit Immanuel James
- Assistant Professor (Forensic Medicine & Toxicology), Christian Medical College, Vellore, Tamil Nadu, India
| | - Hema Eunice Paul
- Associate Physician (Microbiology), Member, Hospital Infection Control Committee, Christian Medical College, Vellore, Tamil Nadu, India
| | - Malathi Murugesan
- Senior Resident (Microbiology), Member, Hospital Infection Control Committee, Christian Medical College, Vellore, Tamil Nadu, India
| | - Deepak Thomas Abraham
- Professor (Endocrine Surgery), Christian Medical College, Vellore, Tamil Nadu, India
| | - Jeyalinda Christopher
- Professor & Head (Emergency Nursing), Christian Medical College, Vellore, Tamil Nadu, India
| | - Annie Valsan
- Senior Manager, Hospital Operations, Christian Medical College, Vellore, Tamil Nadu, India
| | - Joy John Mammen
- Professor (Transfusion Medicine), Associate Director, Christian Medical College, Vellore, Tamil Nadu, India
| | - Priscilla Rupali
- Professor (Infectious Diseases), Christian Medical College, Vellore, Tamil Nadu, India
| | - Ilavarasi Jesudoss
- Professor (Nursing Services), Christian Medical College, Vellore, Tamil Nadu, India
| | - Senthamil Selvan
- Infection Control Nurse, Hospital Infection Control Committee, Christian Medical College, Vellore, Tamil Nadu, India
| | - Prasad Mathews
- Professor (Geriatric Medicine), Medical Superintendent, Christian Medical College, Vellore, Tamil Nadu, India
| | - John Victor Peter
- Professor (Critical Care), Director, Christian Medical College, Vellore, Tamil Nadu, India
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Manoj D, James RI, Delighta M, Johnson LR. Medicolegal autopsies in private medical colleges in India: An urgent need. J Postgrad Med 2022:362950. [PMID: 36511018 PMCID: PMC10394536 DOI: 10.4103/jpgm.jpgm_466_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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James RI, Warlick CA, Diers MD, Gunther R, McIvor RS. Mild preconditioning and low-level engraftment confer methotrexate resistance in mice transplanted with marrow expressing drug-resistant dihydrofolate reductase activity. Blood 2000; 96:1334-41. [PMID: 10942375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Effective engraftment of hematopoietic cells targeted for gene transfer is facilitated by cytoreductive preconditioning such as high-dose total body irradiation (TBI). To minimize the adverse side effects associated with TBI, experiments were conducted to determine whether sublethal doses of TBI would allow sufficient engraftment of MTX-resistant hematopoietic cells to confer survival on recipient mice administered MTX. FVB/N animals were administered 1, 2, or 4 Gy TBI (lethal dose, 8.5 Gy), transplanted with 10(7) FVB/N transgenic marrow cells expressing an MTX-resistant dihydrofolate reductase (DHFR) transgene, and then administered MTX daily for 60 days. Control mice administered 1 Gy with or without subsequent transplantation of normal marrow cells succumbed to MTX toxicity by day 45. In contrast, nearly all animals transplanted with transgenic marrow survived MTX administration, regardless of the TBI dose used for preconditioning. The donor DHFR transgenic marrow engraftment level was proportional to the preconditioning dose of TBI but was surprisingly reduced in animals given 2 or 4 Gy TBI and subsequently administered MTX when compared with control animals administered phosphate-buffered saline. Animals preconditioned with 1 Gy were also protected from MTX toxicity when transplanted with reduced amounts (5 x 10(6) and 1 x 10(6) cells) of DHFR transgenic donor marrow, resulting in low-level (approximately 1%) engraftment. In conclusion, very mild preconditioning allows sufficient low-level engraftment of genetically modified stem cells for in vivo manifestation of the modified phenotype, suggesting the usefulness of mild preconditioning regimens in human gene therapy trials targeting hematopoietic stem cells. (Blood. 2000;96:1334-1341)
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Affiliation(s)
- R I James
- Gene Therapy Program, Institute of Human Genetics, Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA
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Deneen VC, Hunt JM, Paule CR, James RI, Johnson RG, Raymond MJ, Hedberg CW. The impact of foodborne calicivirus disease: the Minnesota experience. J Infect Dis 2000; 181 Suppl 2:S281-3. [PMID: 10804138 DOI: 10.1086/315583] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The first outbreaks of Norwalk virus gastroenteritis in Minnesota were confirmed in 1982. Since then, Norwalk-like caliciviruses have been recognized to be the most common cause of foodborne disease outbreaks, accounting for 41% of all confirmed foodborne outbreaks in Minnesota from 1981-1998. Although laboratory confirmation of caliciviruses in stool samples was not attempted in most of these outbreaks, all conformed to epidemiologic criteria for defining outbreaks of Norwalk virus. Since 1996, the availability of polymerase chain reaction testing at the Minnesota Department of Health has allowed for the confirmation of calicivirus infection among patients involved in epidemiologically defined outbreaks of viral gastroenteritis. Results have confirmed the usefulness of characterizing foodborne disease outbreaks by epidemiologic criteria and also confirmed the importance of human caliciviruses as the leading cause of foodborne disease outbreaks in Minnesota.
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Affiliation(s)
- V C Deneen
- Acute Disease Epidemiology Section, Minnesota Department of Health, Minneapolis, MN 55440, USA.
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James RI, Elton JP, Todd P, Kompala DS. Engineering CHO cells to overexpress a secreted reporter protein upon induction from mouse mammary tumor virus promoter. Biotechnol Bioeng 2000; 67:134-40. [PMID: 10592510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
The mouse mammary tumor virus (MMTV) promoter is induced by the addition of a glucocorticoid hormone or analog such as dexamethasone. The hormone binds to its specific transcription factor, glucocorticoid receptor (GR), and the activated complex then binds to the glucocorticoid response elements (GREs) in the enhancer region of the MMTV promoter to induce the overexpression of downstream genes. We have constructed an expression vector for a reporter protein, secreted alkaline phosphatase (SEAP),controlled by the MMTV promoter and co-transfected this vector along with a GR expression cassette into Chinese hamster ovary (CHO) cells. High producers were cloned and grown in suspension cultures. A very high titer, over 0.4 mg/mL, of SEAP was obtained from this inducible overexpression system, about ten times that achievable with the same reporter protein using the strong constitutive SV40 promoter in CHO cells. A peak production rate of 187 pg SEAP per cell per day was observed within 3 days after induction, compared to the peak rate of 23 pg SEAP per cell per day expressed using the constitutive SV40 promoter. With the reduced or zero growth rate during the protein production phase, this novel MMTV overexpression system is highly suited for optimizing glycoprotein synthesis rates in high cell density fed-batch or perfusion bioreactors.
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Affiliation(s)
- R I James
- Department of Chemical Engineering, University of Colorado, Boulder, Colorado 80309-0424, USA
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James RI, May C, Vagt MD, Studebaker R, McIvor RS. Transgenic mice expressing the tyr22 variant of murine DHFR: protection of transgenic marrow transplant recipients from lethal doses of methotrexate. Exp Hematol 1997; 25:1286-95. [PMID: 9357973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Expression of the arg22, drug-resistant variant of dihydrofolate reductase (DHFR) in hematopoietic cells has been demonstrated to confer resistance to methotrexate (MTX) in mice, even though this variant suffers from low catalytic activity. The recently reported tyr22 variant has the advantage of higher catalytic activity combined with significant resistance to MTX. To evaluate the resistance conferred by tyr22-DHFR in vivo, we generated several transgenic mouse lines carrying a tyr22-DHFR minigene regulated by its natural promoter. The transgene copy number in 11 lines ranged from 6 to 68 copies and ribonuclease protection analysis demonstrated that 4 of these lines expressed significant transgenic DHFR mRNA at 20 to 68% of the endogenous DHFR mRNA level. Marrow from 4 of the 11 lines conferred significant increases in MTX-resistance in comparison with normal marrow when transplanted into lethally irradiated recipients. The ability of the tyr22-DHFR transgenic marrow to confer MTX-resistance to bone marrow transplant (BMT) recipients did not correlate with the level of mRNA expression or the number of transgene copies. However, two lines (lines 11 and 15) that were most effective in maintaining normal hematocrit levels in BMT recipients receiving 1 mg/kg/day MTX exhibited the greatest ability to form MTX-resistant hematopoietic progenitor colonies in vitro. Furthermore, MTX dose escalation studies demonstrated that line 11 marrow conferred resistance in BMT recipients receiving up to 6 mg/kg/day MTX. Southern blot analysis of the BMT recipients 7 months posttransplantation showed a preponderance of transgenic donor-derived cells in bone marrow and spleen, as well as a surprisingly high level in the small intestine. These results indicate that tyr22-DHFR is likely to be superior to arg22-DHFR in conferring MTX-resistance in BMT recipients, illustrating its usefulness for chemoprotection during MTX chemotherapy and also potentially for in vivo selection of transduced cells in gene therapy trials.
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Affiliation(s)
- R I James
- Institute of Human Genetics, and Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis 55455, USA
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May C, James RI, Gunther R, McIvor RS. Methotrexate dose-escalation studies in transgenic mice and marrow transplant recipients expressing drug-resistant dihydrofolate reductase activity. J Pharmacol Exp Ther 1996; 278:1444-51. [PMID: 8819532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Methotrexate (MTX) dose-escalation studies were conducted in two inbred lines of FVB/N transgenic mice expressing distinct drug-resistant dihydrofolate reductases (DHFRs) and in animals transplanted with transgenic marrow. Survival of animals expressing a tryptophan-31 variant DHFR transgene was only slightly improved over that of normal animals, and survival of tryptophan-31 variant DHFR marrow transplant recipients was indistinguishable from that of normal animals (at a MTX dose of 4 mg/kg i.p. daily). In contrast, extended survival was observed for animals expressing an arginine-22 variant (Arg22) DHFR transgene, with the last three of eight animals in this group succumbing at a final MTX dose of 14 mg/kg i.p. daily. Survival was slightly reduced for normal animals transplanted with Arg22 marrow. Interestingly, demise of animals in both Arg22 groups was not associated with the profound drop in hematocrit levels usually observed in MTX-treated animals. These animals were instead characterized by severe atrophy of the gastrointestinal tract, whereas hematocrit levels and marrow histology were relatively normal. Kidney pathology (mesangiocapillary glomerulopathy) was also observed in Arg22 marrow recipients but not in Arg22 transgenics, consistent with expression of the drug-resistance gene in kidney tissues of the transgenics, as demonstrated by ribonuclease protection analysis. Immediate dose-response studies in Arg22 marrow transplant recipients defined a maximum tolerated dose of 4 mg/kg/day MTX, 2 to 3 times that of animals transplanted with normal marrow or of normal untransplanted animals. These results define the extent of chemoprotection afforded by drug-resistant DHFR expression and serve to identify alternate sites of toxicity in animals administered the higher levels of MTX afforded by drug-resistant DHFR expression in the marrow.
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Affiliation(s)
- C May
- Gene Therapy Program, Institute of Human Genetics, University of Minnesota, Minneapolis, USA
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James RI, Menaya J, Hudson K, Devalia V, Ryves J, Evans FJ, Thomas S, Clemens MJ. Role of protein kinase C in induction of gene expression and inhibition of cell proliferation by interferon alpha. Eur J Biochem 1992; 209:813-22. [PMID: 1425689 DOI: 10.1111/j.1432-1033.1992.tb17352.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Recent studies have suggested that protein kinase C (PKC) may be involved in the mechanism of signal transduction by which members of the interferon (IFN) family regulate gene expression and cell phenotype. We have investigated the role of PKC in the control of cell growth and gene expression by IFN alpha in Daudi cells. Treatment of these cells with two analogues of staurosporine, which are potent inhibitors of PKC, completely blocked the induction by IFN alpha of the mRNA for 2',5'-oligoadenylate synthetase and the 6-16 gene. These compounds also inhibited cell proliferation and thymidine incorporation in this system. In contrast, the protein kinase inhibitor 1-(5-isoquinolinylsulphonyl)-2-methylpiperazine (H7) did not significantly inhibit the induction of these genes by IFN alpha and had no effect on Daudi cell growth or thymidine incorporation in the presence or absence of IFN alpha. No effect of IFN alpha on total PKC activity could be observed, and there were no significant changes in the overall levels of individual PKC isoforms or their mRNA following IFN alpha treatment. In contrast, treatment of Daudi cells with the phorbol ester 12-O-tetradecanoylphorbol 13-acetate, which also inhibits cell proliferation, strongly down-regulated PKC. These data suggest that the activity of a PKC species, or a closely related enzyme, may be required both for continued cell proliferation and the response to IFN alpha in Daudi cells, but that IFN-induced growth inhibition does not involve overall down-regulation or change in activity of PKC.
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Affiliation(s)
- R I James
- Department of Cellular and Molecular Sciences, St. George's Hospital Medical School, London, England
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