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Simioni P, Tormene D, Spiezia L, Tognin G, Rossetto V, Radu C, Prandoni P. Inherited Thrombophilia and Venous Thromboembolism. Semin Thromb Hemost 2006; 32:700-8. [PMID: 17024597 DOI: 10.1055/s-2006-951298] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The term thrombophilia includes any inherited and acquired disorders associated with an increased tendency to venous thromboembolism (VTE). Inherited thrombophilia is one of the main determinants of VTE, and the presence of inherited thrombophilic defects exposed carriers to increased risks for VTE compared with noncarriers. There is no clear relationship between clinical manifestations and the type of underlying thrombophilic defect. Thus, the diagnosis of inherited thrombophilia has to be established on a laboratory basis. Carriers of thrombophilic defects may experience thrombosis at a younger age than noncarriers. However, a first thrombotic manifestation that occurs late in life may also be an expression of thrombophilia and this remains in many cases the only etiopathogenetic explanation for the event. Screening of family members of symptomatic probands has the potential to identify still asymptomatic carriers who may benefit from more appropriate thromboprophylaxis during high-risk situations for VTE. Women of fertile age who belong to these thrombophilic families might receive the greatest advantage from screening. Many inherited thrombophilic disorders can be considered risk factors for recurrent VTE, especially if more than one defect is present in the same patient. More intensive or prolonged duration of VTE treatment might be requested for the prevention of recurrent VTE in the most severe thrombophilic conditions. The availability of new methods for the assessment of thrombin generation in terms of endogenous thrombin potential are very promising tools for the identification of those carriers of inherited thrombophilia who will develop thrombosis or who will encounter recurrence of VTE.
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Böhler T, Alex C, Becker E, Becker R, Hoffmann S, Hutzler D, Jung C, Laufersweiler-Lochmann F, Radu C. Qualitätskriterien für ambulante Schulungsprogramme für übergewichtige und adipöse Kinder und Jugendliche. DAS GESUNDHEITSWESEN 2004; 66:748-53. [PMID: 15562345 DOI: 10.1055/s-2004-813772] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND In Germany, 9 to 12 % of all children between five and seven years of age have been shown to be overweight at school entry; 2.5 to 3.5 % of them are obese. Therapeutic intervention for obese children and adolescents is considered to be indicated especially in cases where an increased body mass index (BMI) is accompanied by a disease the effective treatment of which requires weight loss. Furthermore, the child and its family must be willing to actively change their habits. OBJECTIVE A multitude of health care providers have begun to offer multidisciplinary group programme for prevention and treatment of obesity to affected individuals and their families. The Medical Service of the Statutory Health Insurance (MDK) has therefore developed a list of quality and assessment criteria for such programme. METHODS A systematic search for information in international and national publications was performed using standard methodology of evidence-based medicine. Data were extracted and assessed according to pre-defined criteria taking into consideration previously published clinical guidelines and opinions of expert panels. RESULTS Nearly all available studies were of low internal validity and mostly of poor methodological quality. Therefore, no binding recommendations for the design of health education programme for overweight and obese children and adolescents can be given. Potentially successful intervention should combine the following 4 modules: nutrition, physical activity, change of eating habits, physical activity habits and life style using methods of behavioural therapy, and involvement of parents. Such combinations may have the potential to reduce or stabilise the BMI at least during a defined period of time. In younger children, the beneficial effect will be more pronounced if the parents are actively involved. CONCLUSION Up to now informative studies have not reliably shown that the effect of ambulatory health education programmes for overweight and obese children and adolescents and their parents may last for more than one or two years. Therefore, a controlled clinical trial determining the long-term effectiveness of such programme is imperative. The decision whether a defined programmes should be included in such a study could be taken on the basis of the quality indicators and assessment criteria described here.
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Hutzler D, Böhler T, Alex C, Becker R, Hoffmann S, Jung C, Laufersweiler-Lochmann F, Radu C. Wie sind ambulante Adipositas-Programme für Kinder und Jugendliche zu bewerten? DAS GESUNDHEITSWESEN 2004. [DOI: 10.1055/s-2004-833837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Doran H, Pătraşcu T, Radu C. [Acute abdomen in diabetic patients --diagnostical questions]. Chirurgia (Bucur) 2003; 98:119-25. [PMID: 14992132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
The acute abdominal diseases in diabetic patients have some typical clinical features, which may be responsible for delated or even erroneous diagnosis. Severe anatomo-pathological forms of these diseases may advance, despite a rather discreet clinical evidence. The authors analyze a series of 132 diabetic patients with acute abdomen, operated between 1996 and 2001 in Surgical Clinic "I. Juvara", from Clinical Hospital "Dr. I. Cantacuzino"-Bucharest. The difficulties and also the inadvertences of diagnosis are detailed. Finally, a set of indices is presented, in order to help the differential diagnosis between acute abdomen and abdominal signs of the diabetic ketoacidosis.
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Cantini M, Giurisato E, Radu C, Tiozzo S, Pampinella F, Senigaglia D, Zaniolo G, Mazzoleni F, Vitiello L. Macrophage-secreted myogenic factors: a promising tool for greatly enhancing the proliferative capacity of myoblasts in vitro and in vivo. Neurol Sci 2002; 23:189-94. [PMID: 12536288 DOI: 10.1007/s100720200060] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
In this work we set out to determine if the murine macrophage J774 cell line can be used to produce myogenic growth factors. Activated J774 macrophages were grown in serum-free conditions. The macrophage-conditioned medium (MCM) was then used to treat cultures of primary myoblasts and regenerating muscle tissue, in vitro and in vivo respectively. MCM activity in vitro was tested by analyzing the expression of muscle-specific transcription factors, in parallel with the proliferation and differentiation rates of the cells. The macrophage-secreted factors greatly enhanced the proliferative potential of both rat and human primary myoblasts and were found to be highly muscle-specific. In vivo, MCM administration markedly enhanced the regenerative processes in damaged muscles. The ability to produce large amounts of macrophage-secreted myogenic factor(s) in the absence of serum holds great promise for its biochemical characterization and successive application in therapeutic protocols, both for ex vivo gene therapy and for muscle repair.
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Grypiotis P, Ruffatti A, Tonello M, Winzler C, Radu C, Zampieri S, Favaro M, Calligaro A, Todesco S. [Clinical significance of fluoroscopic patterns specific for the mitotic spindle in patients with rheumatic diseases]. Reumatismo 2002; 54:232-7. [PMID: 12404031 DOI: 10.4081/reumatismo.2002.232] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE To determine the clinical significance of anti-NuMA and anti-HsEg5 antibodies in a group of patients affected with rheumatic diseases. MATERIALS AND METHODS Indirect immunofluorescence on HEp-2000 cells at serum dilution of 1:40 was used to examine 26 sera which had previously showed a "mitotic spindle" fluoroscopic pattern type during laboratory routine. RESULTS 21 sera (80,7%) were identified with NuMA and 5 (19,3%) with HsEg5 patterns alone or associated with other ANA patterns. However only patients with isolated positivity and that is 15 with NuMA and 4 with HsEg5 stainings were included in this study. Of the NuMA positive patients 5 were affected with arthropathies associated to different forms of thyroiditis, 2 with seronegative arthritis, 2 with antiphospholipid syndrome, 1 with systemic lupus erythematosus (SLE), 1 with rheumatoid arthritis, 1 with sicca syndrome, 1 with undifferentiated connective tissue disease, 1 with Mycoplasma pneumoniae infection and 1 with retinal thrombosis. Of the HsEg5 positive patients 3 were affected with SLE and 1 with seronegative arthritis. CONCLUSIONS NuMA does not prevail in any defined rheumatic disease, while HsEg5 staining were more frequent (75%) in patients affected with SLE all of whom showing high antibody titres.
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MESH Headings
- Adenocarcinoma/pathology
- Antibodies, Antinuclear/immunology
- Antigens, Nuclear
- Antiphospholipid Syndrome/blood
- Antiphospholipid Syndrome/immunology
- Arthritis/blood
- Arthritis/immunology
- Arthritis, Rheumatoid/blood
- Arthritis, Rheumatoid/immunology
- Autoantibodies/blood
- Autoantibodies/immunology
- Autoimmune Diseases/blood
- Autoimmune Diseases/immunology
- Cell Cycle
- Cell Cycle Proteins
- Centrosome/immunology
- Connective Tissue Diseases/blood
- Connective Tissue Diseases/immunology
- Fluorescent Antibody Technique, Indirect
- Fluorescent Dyes/analysis
- Humans
- Kinesins/analysis
- Kinesins/immunology
- Laryngeal Neoplasms/pathology
- Lupus Erythematosus, Systemic/blood
- Lupus Erythematosus, Systemic/immunology
- Microscopy, Fluorescence
- Nuclear Matrix-Associated Proteins
- Nuclear Proteins/analysis
- Nuclear Proteins/immunology
- Pneumonia, Mycoplasma/blood
- Pneumonia, Mycoplasma/immunology
- Sjogren's Syndrome/blood
- Sjogren's Syndrome/immunology
- Spindle Apparatus/immunology
- Thrombosis/blood
- Thrombosis/immunology
- Thyroiditis, Autoimmune/blood
- Thyroiditis, Autoimmune/immunology
- Tumor Cells, Cultured/immunology
- Tumor Cells, Cultured/ultrastructure
- Xenopus Proteins/analysis
- Xenopus Proteins/immunology
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Pătraşcu T, Doran H, Beluşică L, Marin I, Muşat O, Crihană V, Radu C. [Small bowel tumors -- peculiarities of diagnosis and evolution]. Chirurgia (Bucur) 2002; 97:133-8. [PMID: 12731223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
The authors analyze 13 cases of small bowel tumors. There are emphasized the difficulties of diagnosis, which is rarely established before the laparotomy. In the same time, clinical features are few and operations are often performed too late, in emergency, due to tumors complications (perforation, bleeding, occlusion). There are also presented new etiopathogenic hypothesis, recently mentioned in literature. Surgical treatment is followed by many post-operative complications. Five-years survival is low, under 40% of patients.
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Remsburg RE, Luking A, Bara P, Radu C, Pineda D, Bennett RG, Tayback M. Impact of a buffet-style dining program on weight and biochemical indicators of nutritional status in nursing home residents: a pilot study. JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION 2001; 101:1460-3. [PMID: 11762743 DOI: 10.1016/s0002-8223(01)00352-2] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Catrina SB, Curca E, Catrina AI, Radu C, Coculescu M. Melatonin shortens the survival rate of Ehrlich ascites-inoculated mice. NEURO ENDOCRINOLOGY LETTERS 2001; 22:432-4. [PMID: 11781540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/29/2001] [Accepted: 11/02/2001] [Indexed: 02/23/2023]
Abstract
UNLABELLED OBJECTIVES Pineal gland may have a role in organism's protection against cancer. Melatonin as well as still unidentified low-weight molecular pineal substance(s) have been reported to have growth inhibitory effect on different tumor cells. We tested the influence of melatonin and of a bovine pineal extract on the survival rate of AKR mice inoculated with Ehrlich ascites. The tumor is known to have an accelerated development after pinealectomy. MATERIAL AND METHODS Male AKR mice, kept under a 14/10 hours - Light /Dark cycle, were inoculated intraperitoneally (i.p.) with 1.5x 10(6) Ehrlich ascites cells. On day three after inoculation the animals were divided in three groups (n=10). Each animal received i.p. daily (20.00H), until their death, 250 microl of solution containing melatonin (250 microg), pineal extract (equivalent of 1 bovine pineal gland) or saline. RESULTS The average survival rate of the animals treated with melatonin was shorter (14.8+/-2.23 days) compared to control animals (21.9+/-2.21 days)(p=0.01). The animals treated with the pineal extract had a longer survival rate (22.6 +/- 1.8 days) but not statistically significant. The pineal extract was not available for testing at higher doses. CONCLUSION In our model, melatonin had a deleterious effect on the survival rate raising the question whether it is correct to assume that the hormone shows lack of adverse reactions.
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Remsburg RE, Richards M, Myers S, Shoemaker D, Radu C, Doane L, Green K. Creating a career ladder for nursing assistants in long-term care. Geriatr Nurs 2001; 22:318-25. [PMID: 11780006 DOI: 10.1067/mgn.2001.121000] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This article describes the development, implementation, and evaluation of a career ladder for certified nursing assistants in long-term care. A career ladder is an effective way to maximize the use of unlicensed workers without changing the skill mix (eg, no loss of licensed nursing positions) and allow the licensed nurse more time to perform higher-level clinical tasks, such as assessments, patient education, and documentation. Implementation of an unlicensed worker career ladder also can improve nursing assistant retention.
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Remsburg RE, Sobel T, Cohen A, Koch C, Radu C. Does a liquid supplement improve energy and protein consumption in nursing home residents? Geriatr Nurs 2001; 22:331-5. [PMID: 11780008 DOI: 10.1067/mgn.2001.121001] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
One popular strategy to improve the acceptance and efficacy of oral liquid supplements in long-term care is dispensing them during the medication pass, although few studies support its effectiveness. This study evaluated the impact of a supplement medication pass program on energy and nutrient consumption and weight in nursing home residents. Findings indicate that residents maintained their prestudy weight and had a 29% decrease in supplement energy intake, a 19% increase in food energy intake, and a 17% decrease in net energy intake (supplement plus food). Supplement and food protein intake remained stable. Over longer periods, this reduced energy consumption could lead to weight loss, so routine monitoring and periodic evaluations of resident intake (both food and supplement) are recommended to ensure residents are receiving and consuming adequate amounts of daily energy and nutrients.
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Pătraşcu T, Doran H, Beluşică L, Muşat O, Radu C. [Abdominal hemangiopericytomas]. Chirurgia (Bucur) 2001; 96:505-8. [PMID: 12731193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
We present two cases of hemangiopericytoma, which are analyzed according to medical literature, although only few cases have been reported. Clinical, imagistic and histological findings of these rare vascular tumors are discussed.
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64
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Firan M, Bawdon R, Radu C, Ober RJ, Eaken D, Antohe F, Ghetie V, Ward ES. The MHC class I-related receptor, FcRn, plays an essential role in the maternofetal transfer of gamma-globulin in humans. Int Immunol 2001; 13:993-1002. [PMID: 11470769 DOI: 10.1093/intimm/13.8.993] [Citation(s) in RCA: 242] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The transfer of maternal gamma-globulin (IgG) provides the neonate with humoral immunity during early life. In humans, maternal IgG is transported across the placenta during the third trimester of pregnancy. The expression of the MHC class I-related receptor, FcRn, in the human placenta suggests that this Fc receptor might be involved in the delivery of maternal IgG, but direct evidence to support this is lacking. In the current study an ex vivo placental model has been used to analyze the maternofetal transfer of a recombinant, humanized (IgG1) antibody in which His435 has been mutated to alanine (H435A). In vitro binding studies using surface plasmon resonance indicate that the mutation ablates binding of the antibody to recombinant mouse and human FcRn. Relative to the wild-type antibody, the H435A mutant is deficient in transfer across the placenta. Significantly, the mutation does not affect binding to Fc gamma RIII, an FcR that has been suggested in earlier studies to mediate the transfer of maternal IgG. The analyses demonstrate that binding of an IgG to FcRn is a prerequisite for transport across the perfused placenta. FcRn therefore plays a central role in the maternofetal delivery of IgG and this has implications for the use of protein engineering to improve the properties of therapeutic antibodies.
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Jasani B, Jones CJ, Radu C, Wynford-Thomas D, Navabi H, Mason M, Adams M, Gibbs A. Simian virus 40 detection in human mesothelioma: reliability and significance of the available molecular evidence. FRONTIERS IN BIOSCIENCE : A JOURNAL AND VIRTUAL LIBRARY 2001; 6:E12-22. [PMID: 11282566 DOI: 10.2741/jasani] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Simian virus 40 was discovered as a contaminant of early poliovirus vaccines that were inadvertently administered to millions of people in Europe and the United States between 1955 and 1963. Although SV40 was proven to be oncogenic in rodents and capable of transforming human and animal cells in vitro, its role in human cancer could not be proven epidemiologically. The matter was forgotten until 1993 when SV40 was accidentally found to cause mesotheliomas in hamsters injected intra-cardially. Subsequently, DNA sequences associated with its powerful oncogenic principal, the large T antigen, were found with high frequency in human pleural mesothelioma using the polymerase chain reaction (PCR). Since then many laboratories have confirmed the human findings. However, a few laboratories have failed to reproduce these data and the authors of the studies have claimed that the detection of SV40 DNA may simply represent PCR contamination artefacts. The controversy raised by this viewpoint is reviewed in this article together with a critical appraisal of the reliability of the molecular techniques used to detect SV40 DNA, in order to evaluate the potential aetiopathogenic role of SV40 in human mesothelioma.
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Jasani B, Cristaudo A, Emri SA, Gazdar AF, Gibbs A, Krynska B, Miller C, Mutti L, Radu C, Tognon M, Procopio A. Association of SV40 with human tumours. Semin Cancer Biol 2001; 11:49-61. [PMID: 11243899 DOI: 10.1006/scbi.2000.0346] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
SV40 was discovered as a contaminant of poliovirus vaccines that were inadvertently administered to millions of people in Europe and the United States between 1955 and 1963. Shortly afterwards, SV40 was proven to be oncogenic in rodents and capable of transforming human and animal cells in vitro. The possibility that SV40 might cause tumours in humans thus became a subject of scientific and public interest and scrutiny. However, largely due to a lack of significant epidemiological evidence, interest in assessing SV40's potential carcinogenic role in humans diminished. Recently, many laboratories have reported the presence of SV40-like DNA in a high proportion of human mesotheliomas, ependymomas and osteosarcoma (the three main types of tumours caused by virus in hamsters), renewing the question whether SV40 might be a human tumour virus. Molecular data from these studies are reviewed to re-evaluate the potential role of SV40 as a human carcinogen.
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67
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Doran H, Pătraşcu T, Păcescu E, Marin I, Radu C. [Acute abdomen and diabetic patients--difficulties of diagnosis and therapeutical decision]. Chirurgia (Bucur) 2001; 96:81-4. [PMID: 12731170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
We present a retrospective study based on 50 diabetic patients with acute abdominal diseases. Usually, clinical features were not typical, without defining signs of acute abdomen, despite frequent severe anatomo-pathological forms (6 of 12 acute appendicitis were gangrenous, with generalised or localised peritonitis; 15 of 22 acute colecystitis were gangrenous). In diabetic patients, with metabolic disorders and cetoacidosis, positive diagnosis and the decision of laparotomy are difficult problems, often delated, with a negative influence on the evolutions and prognosis of these patients.
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Remsburg RE, Armacost KA, Radu C, Bennett RG. Two models of restorative nursing care in the nursing home: designated versus integrated restorative nursing assistants. Geriatr Nurs 1999; 20:321-6. [PMID: 10601898 DOI: 10.1053/gn.1999.v20.103929001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A 6-month clinical trial was conducted to evaluate two models of restorative nursing care designed to improve mobility in nursing home residents. The models were compared on number of residents enrolled, documentation of nursing assistant (NA) compliance, and nursing staff satisfaction. The designated model, which relied on one specially trained NA to perform restorative activities on the unit, resulted in higher rates of enrollment, compliance, and staff satisfaction compared with the integrated model, which relied on regular staff NAs who were trained to incorporate restorative activities into their daily routines.
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Thatte J, Qadri A, Radu C, Ward ES. Molecular requirements for T cell recognition by a major histocompatibility complex class II-restricted T cell receptor: the involvement of the fourth hypervariable loop of the Valpha domain. J Exp Med 1999; 189:509-20. [PMID: 9927513 PMCID: PMC2192911 DOI: 10.1084/jem.189.3.509] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/1998] [Revised: 10/20/1998] [Indexed: 11/22/2022] Open
Abstract
The role of two central residues (K68, E69) of the fourth hypervariable loop of the Valpha domain (HV4alpha) in antigen recognition by an MHC class II-restricted T cell receptor (TCR) has been analyzed. The TCR recognizes the NH2-terminal peptide of myelin basic protein (Ac1-11, acetylated at NH2 terminus) associated with the class II MHC molecule I-Au. Lysine 68 (K68) and glutamic acid 69 (E69) of HV4alpha have been mutated both individually and simultaneously to alanine (K68A, E69A). The responsiveness of transfectants bearing wild-type and mutated TCRs to Ac1-11-I-Au complexes has been analyzed in the presence and absence of expression of the coreceptor CD4. The data demonstrate that in the absence of CD4 expression, K68 plays a central role in antigen responsiveness. In contrast, the effect of mutating E69 to alanine is less marked. CD4 coexpression can partially compensate for the loss of activity of the K68A mutant transfectants, resulting in responses that, relative to those of the wild-type transfectants, are highly sensitive to anti-CD4 antibody blockade. The observations support models of T cell activation in which both the affinity of the TCR for cognate ligand and the involvement of coreceptors determine the outcome of the T cell-antigen-presenting cell interaction.
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Borvak J, Richardson J, Medesan C, Antohe F, Radu C, Simionescu M, Ghetie V, Ward ES. Functional expression of the MHC class I-related receptor, FcRn, in endothelial cells of mice. Int Immunol 1998; 10:1289-98. [PMID: 9786428 DOI: 10.1093/intimm/10.9.1289] [Citation(s) in RCA: 208] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Our recent data indicate that the MHC class I-related receptor, FcRn, plays a role in regulating serum IgG levels, in addition to its known role in transferring IgG from mother to young. In the current study, the distribution of FcRn in adult mice has been investigated using several approaches. First, tissue distribution of anti-FcRn F(ab')2, murine IgG1 and recombinant, IgG1-derived Fc-hinge fragments has been analyzed, and these FcRn binding proteins localize predominantly in skin and muscle with lesser amounts in liver and adipose tissue. Second, histochemical analyses of muscle and liver with anti-FcRn F(ab')2 indicate that FcRn is expressed in the endothelium of small arterioles and capillaries, but not in larger vessels such as the central vein and portal vasculature. Third, immunoprecipitation and immunofluorescence studies of cultured murine endothelial cells show that functional FcRn is expressed in these cells, and is located within vesicular structures in the cytosol and not on the membrane. Taken together the data demonstrate that FcRn is expressed in functionally active form in endothelial cells, indicating that these cells are a possible site at which serum IgG homeostasis is maintained.
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Ghetie V, Popov S, Borvak J, Radu C, Matesoi D, Medesan C, Ober RJ, Ward ES. Increasing the serum persistence of an IgG fragment by random mutagenesis. Nat Biotechnol 1997; 15:637-40. [PMID: 9219265 DOI: 10.1038/nbt0797-637] [Citation(s) in RCA: 180] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The major histocompatibility complex (MHC) class I-related receptor FcRn is involved in regulating serum gammaglobulin (IgG) levels in mice. With the aim of increasing the serum half-life of a recombinant murine Fc gamma 1 fragment, the affinity for binding to FcRn at pH 6.0 has been increased by random mutagenesis of Thr252, Thr254, and Thr256 followed by selection using bacteriophage display. These residues were chosen as they are in proximity to the FcRn-IgG (Fc) interaction site. Two mutants with higher affinity (due to lower off-rates) than the wild-type Fc have been isolated and analyzed in pharmacokinetic studies in mice. The mutant with the highest affinity has a significantly longer serum half-life than the wild type fragment, despite its lower off-rate from FcRn at pH 7.4. The results provide support for the involvement of FcRn in the homeostasis of serum IgGs in mice. The indications that a homologous FcRn regulates IgG levels in humans suggest that this approach has implications for increasing the serum persistence of therapeutic antibodies.
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Medesan C, Matesoi D, Radu C, Ghetie V, Ward ES. Delineation of the amino acid residues involved in transcytosis and catabolism of mouse IgG1. THE JOURNAL OF IMMUNOLOGY 1997. [DOI: 10.4049/jimmunol.158.5.2211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
The MHC class I-related receptor, FcRn, is involved in both the transcytosis of serum gamma-globulins (IgGs) and in regulating their serum persistence. The interaction site of FcRn on the Fc region of rodent IgG has been mapped to residues at the CH2-CH3 domain interface using site-directed mutagenesis and x-ray crystallographic analyses. In the current study, the role of individual residues (H310, H433, and N434) at this interface in mediating the Fc-FcRn interaction has been investigated using recombinant, mutated Fc hinge fragments derived from mouse IgG1. In addition, two highly conserved Fc histidines (H435 and H436) have been mutated to alanine, and the resulting mutated Fc hinge fragments were analyzed in both transcytosis and pharmacokinetic studies in mice and in competition binding assays using recombinant, soluble FcRn. The analyses indicate that mutation of H310, H435, and, to a lesser extent, H436 to alanine results in reduced activity of the Fc hinge fragments in both in vivo and in vitro assays. Thus, in addition to the previously defined role of 1253 in the FcRn-IgG interaction, these histidines play a key role in mediating the functions conducted by this Fc receptor. The effects of these mutations on binding of Fc hinge fragments to staphylococcal protein A have also been analyzed and demonstrate a partial, but not complete, overlap of the FcRn and staphylococcal protein A interaction sites on mouse IgG1.
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Medesan C, Matesoi D, Radu C, Ghetie V, Ward ES. Delineation of the amino acid residues involved in transcytosis and catabolism of mouse IgG1. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1997; 158:2211-7. [PMID: 9036967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The MHC class I-related receptor, FcRn, is involved in both the transcytosis of serum gamma-globulins (IgGs) and in regulating their serum persistence. The interaction site of FcRn on the Fc region of rodent IgG has been mapped to residues at the CH2-CH3 domain interface using site-directed mutagenesis and x-ray crystallographic analyses. In the current study, the role of individual residues (H310, H433, and N434) at this interface in mediating the Fc-FcRn interaction has been investigated using recombinant, mutated Fc hinge fragments derived from mouse IgG1. In addition, two highly conserved Fc histidines (H435 and H436) have been mutated to alanine, and the resulting mutated Fc hinge fragments were analyzed in both transcytosis and pharmacokinetic studies in mice and in competition binding assays using recombinant, soluble FcRn. The analyses indicate that mutation of H310, H435, and, to a lesser extent, H436 to alanine results in reduced activity of the Fc hinge fragments in both in vivo and in vitro assays. Thus, in addition to the previously defined role of 1253 in the FcRn-IgG interaction, these histidines play a key role in mediating the functions conducted by this Fc receptor. The effects of these mutations on binding of Fc hinge fragments to staphylococcal protein A have also been analyzed and demonstrate a partial, but not complete, overlap of the FcRn and staphylococcal protein A interaction sites on mouse IgG1.
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Medesan C, Radu C, Kim JK, Ghetie V, Ward ES. Localization of the site of the IgG molecule that regulates maternofetal transmission in mice. Eur J Immunol 1996; 26:2533-6. [PMID: 8898970 DOI: 10.1002/eji.1830261038] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Site-directed mutagenesis of a recombinant Fc hinge fragment has recently been used to localize the site of the mouse IgG1 (mIgG1) molecule that is involved in the intestinal transfer of recombinant Fc hinge fragments in neonatal mice. This site encompasses Ile-253, His-310, Gln-311, His-433 and Asn-434, localized at the CH2-CH3 domain interface and overlapping with the staphylococcal protein A-binding and catabolic sites. In the present study, the effect of these mutations on the maternofetal transfer of Fc hinge fragments has been studied. Experiments to analyze transfer of radiolabeled Fc hinge fragments from the circulation of 15-18 day pregnant mice to fetuses in utero demonstrate that the mutations affect the maternofetal transmission in a way that correlates closely with the effects of the mutations on intestinal transfer and catabolism. The studies indicate that the neonatal Fc receptor, FcRn, is involved in transcytosis across both yolk sac and neonatal intestine in addition to the regulation of IgG catabolism.
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Voiculescu CL, Bălăşoiu M, Turculeanu A, Radu C, Avramescu C, Radu E. Different patterns of some systemic immunological cell markers in HIV only, and HIV/hepatitis C-infected children. PEDIATRIC AIDS AND HIV INFECTION 1996; 7:31-6. [PMID: 11361470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
In three groups of children, aged 4-6 years (i.e., human immunodeficiency virus [HIV]-negative controls, HIV-seropositive, and dually HIV/hepatitis C virus (HCV)-seropositive), two types of immunological investigations in blood cells were performed: (a) numerical assays, consisting of flow cytometric measurement of different lymphocyte sets or subsets, as follows: CD3+, CD19+, CD4+, CD16+/CD56+; (b) functional assays, consisting of interleukin-1 (IL-1) levels as well as natural killer (NK)-cell dependent cytotoxicity, in CD14+, or CD16+/CD56+ sorted cells, respectively. Results revealed, in addition to the classic markers (i.e., lower numbers of CD4+ cells and a decreased CD4+/CD8+ ratio in both infected groups of subjects) other findings, as follows: increased numbers of CD8+ cells in dually infected children, accompanied by a lower CD4+/CD8+ ratio, as compared to HIV-infected alone; diminished numbers of CD16+/CD56+ cells in both groups of infected patients were correlated with a lower NK-cell cytotoxicity rate; a reduced capacity for IL-1 synthesis of sorted macrophages both in HIV-only and in HIV/HCV-seropositive subjects, but significantly more marked in dually infected children. The importance of the present data in the immune monitoring of AIDS disease in a pediatric population is discussed.
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