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Miqdad MA, Kosaraju K, Mohamad A, Hulwi H, Rais U, Taleb M, Aloreibi T. Clostridium difficile Infection: Risk and Poor Prognostic Factors at a Tertiary Hospital in the Eastern Region of Saudi Arabia. Cureus 2023; 15:e39193. [PMID: 37378089 PMCID: PMC10291994 DOI: 10.7759/cureus.39193] [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] [Accepted: 05/18/2023] [Indexed: 06/29/2023] Open
Abstract
BACKGROUND Clostridium difficile (C. difficile) is a common cause of hospital-acquired diarrhea. It is associated with significantly higher mortality and morbidity in addition to the cost-effectiveness burden on the healthcare system. The primary risk factors for C. difficile infection (CDI) are past C. difficile exposure, proton pump inhibitors, and antibiotic usage. These risk factors are also associated with poor prognosis. OBJECTIVE This study was performed in Dr. Sulaiman Al Habib Tertiary Hospital in the Eastern Region of Saudi Arabia. The aim was to evaluate the risk and prognostic factors of CDI and their association with the outcomes of hospital stay, such as complications, length of stay (LOS), and treatment duration. PATIENTS AND METHODS This is a retrospective cohort study for all patients who tested for C. difficile in the medical department. The target population was all adult patients ≥16 years with positive stool toxins for C. difficile between April 2019 and July 2022. The main outcome measures are risk and poor prognostic factors for CDI. RESULTS C. difficle infection patients were included in the study; 12 (52.2%) were female, and 11 (47.8%) were male. The mean age of the patients was 58.3 (SD: 21.5) years; 13 (56.5%) patients were below 65 years, and 10 were above 65 years. Only four patients were without comorbidities, and 19 (82.6%) patients had various comorbidities. Importantly, hypertension was the most common comorbidity in 47.8% of the patients. Furthermore, advanced age significantly impacted the hospital LOS as the mean age among patients who stayed at the hospital less than four days and those who stayed ≥4 days was 49.08 (19.7) and 68.36 (19.5), respectively (P = .028). CONCLUSION Advanced age was the most frequent poor prognostic factor among our inpatient participants with positive CDI. It was significantly associated with longer hospital LOS, more complications, and longer treatment duration.
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Affiliation(s)
- Mohammed A Miqdad
- Internal Medicine, Dr. Sulaiman Al Habib Medical Group, Khobar, SAU
- Tele-Geriatric Research Fellowship, Michigan State University, Michigan, USA
| | | | - Abdullah Mohamad
- Internal Medicine, Dr. Sulaiman Al Habib Medical Group, Khobar, SAU
| | - Hasan Hulwi
- Internal Medicine, Dr. Sulaiman Al Habib Medical Group, Khobar, SAU
| | - Ubaid Rais
- Pharmacology, Dr. Sulaiman Al Habib Medical Group, Khobar, SAU
| | - Mohammad Taleb
- Internal Medicine, Dr. Sulaiman Al Habib Medical Group, Khobar, SAU
| | - Talal Aloreibi
- Infectious Diseases, Dr. Sulaiman Al Habib Medical Group, Khobar, SAU
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Miqdad MA, Mohamad A, Ali F, Mourad AR, Alamri A. Methylprednisolone-Induced Symptomatic Sinus Bradycardia in a Multiple Sclerosis Patient: A Case Report. Cureus 2022; 14:e21443. [PMID: 35223228 PMCID: PMC8857754 DOI: 10.7759/cureus.21443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2022] [Indexed: 11/18/2022] Open
Abstract
Intermittent high-dose methylprednisolone therapy is widely used for various autoimmune conditions treatment. Common side effects are well known and monitored carefully during therapy. Although cardiovascular adverse events are uncommon, they have been increasingly reported in the literature. This is a case of a 30-year-old female who developed symptomatic sinus bradycardia after receiving three grams of intravenous methylprednisolone pulse therapy for multiple sclerosis flare-ups. Her pulse rate reached 40bpm, together with lightheadedness and chest tightness. An electrocardiogram confirmed sinus bradycardia, for which she was initially managed by splitting the methylprednisolone dose in half; however, 12 hours later, the heart rate decreased further to 35bpm, and her symptoms worsened. Subsequently, the medicine was omitted, and the patient shifted to the intensive care unit for close observation and monitoring. She was treated conservatively with close observation resulted in a gradual normalization of the heart rate. The diagnosis of methylprednisolone pulse-induced bradycardia was made after excluding other common etiologies of sinus bradycardia. This case report aims for careful cardiovascular monitoring in patients receiving high doses of methylprednisolone due to the dose-dependent cardiovascular risks.
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Miqdad MA, Mohamad A, Ali F, Kawari M, Alboainain S. Intracardiac Thrombus Formation and Bilateral Pulmonary Embolisms in a Patient With Behcet's Disease While on Regular Infliximab Infusion: A Case Report. Cureus 2021; 13:e18592. [PMID: 34765357 PMCID: PMC8575333 DOI: 10.7759/cureus.18592] [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] [Accepted: 10/07/2021] [Indexed: 11/24/2022] Open
Abstract
Vascular complications of Behcet'sdisease, including intracardiac thrombus formation, are one of the significant causes of mortality and morbidity in this population. Similar to other vasculitic disorders, Behcet's disease is primarily treated with immunosuppressants. While the benefit of adding anticoagulants in Behcet's disease with thromboembolism remains debatable, some literature encourages its use with concomitant intracardiac thrombus. Herewith, we present the case of a young male who was diagnosed with bilateral pulmonary embolism in addition to right ventricle intracardiac thrombus upon his scheduled dose of infliximab infusion. He was managed by adding azathioprine to his regimen together with oral prednisolone and warfarin with a target international normalized ratio of 2-3. This case report addresses the importance and outcome of early identification of Behcet's disease's vascular complications and immediate initiation of anticoagulation accordingly.
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Affiliation(s)
- Mohammed A Miqdad
- Department of Internal Medicine, Dr. Sulaiman Al Habib Medical Group, Khobar, SAU.,Department of Internal Medicine, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Abdullah Mohamad
- Department of Internal Medicine, Dr. Sulaiman Al Habib Medical Group, Khobar, SAU
| | - Fawaz Ali
- Department of Internal Medicine, Dr. Sulaiman Al Habib Medical Group, Khobar, SAU
| | - Mohammed Kawari
- Department of Internal Medicine, Unit of Hematology, Dr. Sulaiman Al Habib Medical Group, Khobar, SAU
| | - Salha Alboainain
- Department of Rheumatology, Dr. Sulaiman Al Habib Medical Group, Khobar, SAU
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Chin YK, Ina-Salwany MY, Zamri-Saad M, Amal MNA, Mohamad A, Lee JY, Annas S, Al-Saari N. Effects of skin abrasion in immersion challenge with Vibrio harveyi in Asian seabass Lates calcarifer fingerlings. Dis Aquat Organ 2020; 137:167-173. [PMID: 31942862 DOI: 10.3354/dao03435] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Skin abrasions often occur in farmed fish following handling by labourers, injury by farm facilities, cannibalism and ectoparasites. Vibrio spp. are opportunistic pathogens that can invade host fish through damaged tissues and cause outbreaks of vibriosis. This study describes the effect of skin abrasions on the infectivity of V. harveyi using Asian seabass Lates calcarifer (Bloch, 1790) fingerlings as a case example and compares bacterial load and fish survival following immersion challenge with different doses. In total, 315 fish (6.67 ± 1.8 g) were divided into 3 treatments: skin abrasion followed by immersion infection, immersion infection only and an uninfected, uninjured control. Fish in the infection treatments were divided into 3 subgroups and exposed in triplicate to a 7 d immersion challenge with 106, 107 and 108 CFU ml-1 of live V. harveyi. No mortalities were observed in the control and immersion infection groups. However, fish in the skin abrasion treatment group that were infected with 108 CFU ml-1 of live V. harveyi showed signs of progressing disease throughout the experiment, which resulted in mortalities. Significantly higher bacterial loads (p < 0.05) were recorded in the intestine, liver and gills of the fish in this group. Fish in the skin abrasion treatment that were exposed to 107 and 108 CFU ml-1 of V. harveyi showed 100% mortality by Days 5 and 4, respectively. These findings confirm that skin injuries increase the susceptibility of seabass fingerlings to V. harveyi infection.
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Affiliation(s)
- Y K Chin
- Laboratory of Marine Biotechnology (MARSLAB), Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
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Che Sulaiman IS, Chieng BW, Osman MJ, Ong KK, Rashid JIA, Wan Yunus WMZ, Noor SAM, Kasim NAM, Halim NA, Mohamad A. A review on colorimetric methods for determination of organophosphate pesticides using gold and silver nanoparticles. Mikrochim Acta 2020; 187:131. [PMID: 31940088 DOI: 10.1007/s00604-019-3893-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 10/06/2019] [Indexed: 01/08/2023]
Abstract
This review (with 99 refs.) summarizes the progress that has been made in colorimetric (i.e. spectrophotometric) determination of organophosphate pesticides (OPPs) using gold and silver nanoparticles (NPs). Following an introduction into the field, a first large section covers the types and functions of organophosphate pesticides. Methods for colorimetric (spectrophotometric) measurements including RGB techniques are discussed next. A further section covers the characteristic features of gold and silver-based NPs. Syntheses and modifications of metal NPs are covered in section 5. This is followed by overviews on enzyme inhibition-based assays, aptamer-based assays and chemical (non-enzymatic) assays, and a discussion of specific features of colorimetric assays. Several Tables are presented that give an overview on the wealth of methods and materials. A concluding section addresses current challenges and discusses potential future trends and opportunities. Graphical abstractSchematic representation of organophosphate pesticide determinations based on aggregation of nanoparticles (particular silver or gold nanoparticles). This leads to a color change which can be determined visually and monitored by a red shift in the absorption spectrum.
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Affiliation(s)
- I S Che Sulaiman
- Research Centre for Chemical Defence, Universiti Pertahanan Nasional Malaysia (National Defence University of Malaysia), Sungai Besi Camp, 57000, Kuala Lumpur, Malaysia
| | - B W Chieng
- Research Centre for Chemical Defence, Universiti Pertahanan Nasional Malaysia (National Defence University of Malaysia), Sungai Besi Camp, 57000, Kuala Lumpur, Malaysia
| | - M J Osman
- Department of Chemistry and Biology, Centre for Defence Foundation Studies, National Defence University of Malaysia, Sungai Besi Camp, 57000, Kuala Lumpur, Malaysia
| | - K K Ong
- Research Centre for Chemical Defence, Universiti Pertahanan Nasional Malaysia (National Defence University of Malaysia), Sungai Besi Camp, 57000, Kuala Lumpur, Malaysia. .,Department of Chemistry and Biology, Centre for Defence Foundation Studies, National Defence University of Malaysia, Sungai Besi Camp, 57000, Kuala Lumpur, Malaysia.
| | - J I A Rashid
- Department of Chemistry and Biology, Centre for Defence Foundation Studies, National Defence University of Malaysia, Sungai Besi Camp, 57000, Kuala Lumpur, Malaysia
| | - W M Z Wan Yunus
- Centre for Tropicalisation, National Defence University of Malaysia, Sungai Besi Camp, 57000, Kuala Lumpur, Malaysia
| | - S A M Noor
- Department of Chemistry and Biology, Centre for Defence Foundation Studies, National Defence University of Malaysia, Sungai Besi Camp, 57000, Kuala Lumpur, Malaysia
| | - N A M Kasim
- Research Centre for Chemical Defence, Universiti Pertahanan Nasional Malaysia (National Defence University of Malaysia), Sungai Besi Camp, 57000, Kuala Lumpur, Malaysia.,Department of Chemistry and Biology, Centre for Defence Foundation Studies, National Defence University of Malaysia, Sungai Besi Camp, 57000, Kuala Lumpur, Malaysia
| | - N A Halim
- Department of Chemistry and Biology, Centre for Defence Foundation Studies, National Defence University of Malaysia, Sungai Besi Camp, 57000, Kuala Lumpur, Malaysia
| | - A Mohamad
- Centre of Foundation Studies for Agricultural Science, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
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Chew W, Jong W, Jamaluddin Z, Fasha H, Kadri A, Mohamad A, Ho G. PO-178: A single institutional audit of setup errors for 3DCRT rectal cancers. Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(20)30520-x] [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: 10/23/2022]
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Porter J, Mohamad A, Khanbhai M, Muhammad K. Developing an in-house simulated surgical skills course for foundation doctors. Int J Surg 2014. [DOI: 10.1016/j.ijsu.2014.08.111] [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: 11/25/2022]
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Katas H, Mohamad A, Zin N. Physicochemical Effects of Chitosan-Tripolyphosphate Nanoparticles on Antibacterial Activity against Gram-positive and Gram-negative Bacteria. J of Medical Sciences 2011. [DOI: 10.3923/jms.2011.192.197] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Ayas M, Al-Seraihi A, Al-Jefri A, Al-Ahmari A, Al-Mahr M, Al-Ghonaium A, Al-Muhsen S, Al-Mousa H, Al-Dhekri H, Alsaud B, Eldali A, Mohamad A, Al-Humaidan H, Chadrawi A, Al-Kaff M, Al-Hassnan Z, El-Solh H. Unrelated cord blood transplantation in pediatric patients: a report from Saudi Arabia. Bone Marrow Transplant 2010; 45:1281-6. [PMID: 20010867 DOI: 10.1038/bmt.2009.350] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 10/27/2009] [Accepted: 10/29/2009] [Indexed: 11/08/2022]
Abstract
In unrelated cord blood (UCB) transplantation, survival has been shown to correlate with the degree of HLA matching. Thus, to extend transplant access to different ethnic backgrounds, many western UCB transplantation banks now encourage donation from non-Caucasians. Until recently, Saudi Arabia did not have a national UCB bank. In this study we report our experience in UCB transplantation in children using units procured from western cord blood banks. A total of 97 children underwent unrelated UCB transplantation at King Faisal Specialist Hospital and Research Center (KFSHRC), of which 95 were of Arab ethnicity. A total of 30 patients had malignant disorders, 25 patients had non-malignant hematological disorders and 42 patients had inborn errors. Conditioning was according to disease, with six patients receiving reduced-intensity regimens. In all, 46 patients received one-Ag-mismatched units and 51 received two-Ag-mismatched units. Engraftment occurred in 93% of patients, the 100-TRM was 15%, acute GVHD developed in 20% of patients and chronic GVHD occurred in 9% of patients. The 5-year OS and EFS estimates were 52 and 43%, respectively. The search for UCB transplantation units for Saudi patients in western banks yielded reasonably compatible units for our patients; the results are consistent with published data. Our data are encouraging for UCB transplant programs in countries in which there are no national UCB transplantation banks.
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Affiliation(s)
- M Ayas
- Section of Pediatric Stem Cell Transplantation, Department of Pediatric Hematology-Oncology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
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Abstract
The objective of this study was to investigate the in vitro and in vivo drug release performance of a rupturable multiparticulate pulsatile system, coated with aqueous polymer dispersion Aquacoat ECD. Acetaminophen was used as a model drug, because in vivo performance can be monitored by measuring its concentration in saliva. Drug release was typical pulsatile, characterized by lag time, followed by fast drug release. Increasing the coating level of outer membrane lag time was clearly delayed. In vitro the lag time in 0.1 N HCl was longer, compared to phosphate buffer pH 7.4 because of ionisable ingredients present in the formulation (crosscarmelose sodium and sodium dodecyl sulphate). In vitro release was also longer in medium with higher ion concentration (0.9% NaCl solution compared to purified water); but independent of paddle rotation speed (50 vs.100 rpm). Macroscopically observation of the pellets during release experiment confirms that the rupturing of outer membrane was the main trigger for the onset of release. At the end of release outer membrane of all pellets was destructed and the content completely released. However, pellets with higher coating level and correspondingly longer lag time showed decreased bioavailability of acetaminophen. This phenomenon was described previously and explained by decreased liquid flow in the lower part of intestine. This disadvantage can be considered as a limitation for drugs (like acetaminophen) with high dose and moderate solubility; however, it should not diminish performance of the investigated system in principle.
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Affiliation(s)
- A Mohamad
- College of Pharmacy, Freie Universität Berlin, Kelchstr, Berlin, Germany
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Dashevsky A, Bussemer T, Mohamad A, Bodmeier R. Process and Formulation Variables Affecting the Performance of a Rupturable Capsule‐Based Drug Delivery System with Pulsatile Drug Release. Drug Dev Ind Pharm 2004; 30:171-9. [PMID: 15089051 DOI: 10.1081/ddc-120028712] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [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]
Abstract
The objective of this study was to optimize several process and formulation parameters, which influence the performance of a rupturable, pulsatile drug delivery system. The system consisted of a drug-containing hard gelatin capsule, a swelling layer of croscarmellose (Ac-Di-Sol) and a binder, and an outer ethylcellulose coating. Polyvinyl pyrrolidone (Kollidon 90F) was superior to HPMC and HPC as a binder for the swelling layer with regard to binding (adherence to capsule) and disintegration properties of the swelling layer. The capsule-to-capsule uniformity in the amount of swelling layer and outer ethylcellulose coating, which significantly affected the lag time prior to rupture of the capsule, was optimized by decreasing the batch size, and by increasing the rotational pan speed and the distance between the spray nozzle and the product bed. The type of baffles used in the coating pan also affected the layering uniformity. Fully-filled hard gelatin capsules had a shorter lag time with a higher reproducibility compared to only half-filled capsules, because the swelling pressure was directed primarily to the outer ethylcellulose coating and not to the inner capsule core. Stability studies revealed that the lag time of the capsules was stable over a 240-day period when the moisture content was kept unchanged.
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Affiliation(s)
- A Dashevsky
- College of Pharmacy, Freie Universität Berlin, Berlin, Germany.
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Bartram U, Molin DG, Wisse LJ, Mohamad A, Sanford LP, Doetschman T, Speer CP, Poelmann RE, Gittenberger-de Groot AC. Double-outlet right ventricle and overriding tricuspid valve reflect disturbances of looping, myocardialization, endocardial cushion differentiation, and apoptosis in TGF-beta(2)-knockout mice. Circulation 2001; 103:2745-52. [PMID: 11390347 DOI: 10.1161/01.cir.103.22.2745] [Citation(s) in RCA: 215] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Transforming growth factor-beta(2) (TGF-beta(2)) is a member of a family of growth factors with the potential to modify multiple processes. Mice deficient in the TGF-beta(2) gene die around birth and show a variety of defects of different organs, including the heart. METHODS AND RESULTS We studied the hearts of TGF-beta(2)-null mouse embryos from 11.5 to 18.5 days of gestation to analyze the types of defects and determine which processes of cardiac morphogenesis are affected by the absence of TGF-beta(2). Analysis of serial sections revealed malformations of the outflow tract (typically a double-outlet right ventricle) in 87.5%. There was 1 case of common arterial trunk. Abnormal thickening of the semilunar valves was seen in 4.2%. Associated malformations of the atrioventricular (AV) canal were found in 62.5% and were composed of perimembranous inlet ventricular septal defects (37.5%), AV valve thickening (33.3%), overriding tricuspid valve (25.0%), and complete AV septal defects (4.2%). Anomalies of the aorta and its branches were seen in 33.3%. Immunohistochemical staining showed failure of myocardialization of the mesenchyme of the atrial septum and the ventricular outflow tract as well as deficient valve differentiation. Morphometry documented this to be associated with absence of the normal decrease of total endocardial cushion volume in the older stages. Apoptosis in TGF-beta(2)-knockout mice was increased, although regional distribution was normal. CONCLUSIONS TGF-beta(2)-knockout mice exhibited characteristic cardiovascular anomalies comparable to malformations seen in the human population.
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Affiliation(s)
- U Bartram
- Department of Anatomy and Embryology, Leiden University, Leiden, the Netherlands
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Sharma HS, Reddy SC, Mohamad A, Kamal MZ, Halder D. Metastatic osteosarcoma of the ethmoid: an unusual cause of recurrent epistaxis and proptosis. J Laryngol Otol 1996; 110:676-8. [PMID: 8759546 DOI: 10.1017/s0022215100134590] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [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: 02/02/2023]
Abstract
Osteosarcoma is the most common primary malignant tumour of bone and it usually metastasises to the lung. In the nasal cavity metastatic disease is extremely rare. We describe a case of osteosarcoma presenting with recurrent epistaxis, and proptosis due to secondaries in the nasal cavity. To our knowledge such a case has not been reported previously in the available English literature.
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Affiliation(s)
- H S Sharma
- Department of Otorhinolaryngology, School of Medical Sciences, Universiti Sains Malaysia, Kelantan, Malaysia
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Abstract
The region of the hepatitis B virus (HBV) genome coding for the viral envelope proteins contains three inphase ATGs that are conserved among viral subtypes. Each of these ATGs can be used as mRNA initiation codons. The three translated proteins share a carboxy-terminal region (the S protein) and extend amino-terminally to include the pre-S2 region in the middle (M) protein, and the pre-S1 and pre-S2 regions in the large (L) protein. We have inserted the HBV DNA coding for the M protein into a baculovirus expression vector. Infected insect cells transcribe a mRNA that is initiated solely within a baculovirus promoter, and that contains the initiator codons for both M and S proteins. Although these cells primarily secrete the M protein, the major translational product is the S protein, which is not secreted. This preferential translation, the result of the use of an internal initiator codon, demonstrates that the regulation of HBV envelope protein production can occur at the translational level.
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Affiliation(s)
- P M Price
- Department of Biochemistry, Mount Sinai School of Medicine, New York, NY 10029
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Fukusato T, Mohamad A, Gerber MA, Thung SN. Synergistic effect of 5-azacytidine and gamma-interferon or dimethyl sulfoxide on expression of HLA class I antigens by PLC-PRF-5 cells. TOHOKU J EXP MED 1988; 155:117-28. [PMID: 2463698 DOI: 10.1620/tjem.155.117] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [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: 01/01/2023]
Abstract
In order to elucidate the mechanism by which HLA antigens expression is induced or enhanced on the injured or transformed hepatocytes, we have made in vitro studies using human hepatic tumor-derived cell lines as a model system. In the present study, PLC-PRF-5 cells that have the integrated form of hepatitis B virus genome in DNA were treated with 5-azacytidine (5-azaC) in combination with gamma-interferon (IFN-gamma) or dimethyl sulfoxide (DMSO). HLA antigens on the cell surface were quantitated by using a modified cell-ELISA method. As a result, it was demonstrated that DMSO- or IFN-gamma-treatment enhanced expression of HLA class I antigens on the cell surface. In addition, enhanced expression of the antigens on PLC-PRF-5 cells treated with 5-azaC in combination with IFN-gamma or DMSO represented a synergistic effect of these inducers on HLA class I antigens expression although no changes in HLA antigens expression were induced after 5-azaC-treatment alone in short-term experiments. Furthermore, an indirect immunofluorescent analysis of hepatitis B surface antigen on the cells demonstrated increased expression of the antigen after 5-azaC-treatment alone. HLA class II antigens and hepatitis B core antigen were not induced even after those treatments and also not after a long-term experiment. These results might indicate possible modulation of HLA class I and hepatitis B virus antigens expression on the cultured cells by a DNA hypomethylating agent, 5-azaC.
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Affiliation(s)
- T Fukusato
- Department of Pathology, Mount Sinai School of Medicine, New York, NY
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Zelent AZ, Sells MA, Price PM, Mohamad A, Acs G, Christman JK. Murine cells carrying integrated tandem genomes of hepatitis B virus DNA transcribe RNAs from endogenous promoters on both viral strands and express middle and major viral envelope proteins. J Virol 1987; 61:1108-15. [PMID: 3029405 PMCID: PMC254071 DOI: 10.1128/jvi.61.4.1108-1115.1987] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Clone 4.10 cells were isolated as a methotrexate-resistant clone arising after cotransfection of mouse 3T3 cells with plasmid DNA containing a head-to-tail dimer of the hepatitis B virus (HBV) genome and DNA coding for methotrexate-resistant dihydrofolate reductase. The majority of methotrexate-resistant clones derived by this procedure have been found to contain multiple copies of the HBV genome, but the intact HBV dimer was rarely preserved. In contrast, 4.10 cells contained at least 40 copies of intact HBV dimer per cell. These cells produced large amounts of 22-nm hepatitis B surface antigen particles that included viral envelope proteins reactive with the pre-S2 region-specific antibody, indicating transcription and translation of the pre-S2 and S regions of the integrated viral genomes. The cells also synthesized viral e antigen, which was released into the culture medium. Characterization of polyadenylated viral RNAs transcribed from the long (minus) strand of the integrated HBV DNA demonstrated the presence of shorter-than-genome-length RNAs containing only X region sequences, shorter-than-genome-length RNAs containing both X and S region sequences, and longer-than-genome-length RNAs containing core, X, and S region sequences. Start sites for transcripts were mapped 5' to and within the pre-S region and 5' to and within the precore region at approximately the same sites as those utilized for HBV transcription during viral replication in infected livers. Polyadenylated RNA transcripts complementary to the short (plus) strand of HBV that initiated and terminated within the intact and integrated head-to-tail tandem viral genomes were also detected.
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Smidt U, Mohamad A, Worth G, Gasthaus L, Stahlmann W. [The frequency of chronic bronchitis between knappschaft-insured and non-knappschaft-insured men and women (author's transl)]. Pneumonologie 1974; 150:227-35. [PMID: 4417123 DOI: 10.1007/bf02179324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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