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Biomedical subjects

S Nelson

Publications and source records attributed to S Nelson.

At least 37 records · Page 2Linked to original sources
PubMed2001

Oral jaw behaviors in TMD and bruxism: a comparison study by severity of bruxism.

The purpose of this study was to document the prevalence of oral jaw behaviors concomitant to bruxism in TMD+bruxing behavior patients and in nonbruxer controls. Clinical examination, questionnaires, and specific criteria to allocate patients to mild, moderate, and severe groups of TMD and bruxers were used. The sample consisted of 274 TMD+bruxing behavior patients and 52 control non-bruxing behavior groups evaluated at the Center for the Study of TMD. The mean age of the TMD+bruxing behavior group was about 33.11 years old (range 16.66, SD = 11.52) as compared to 34.90 years old (range 17-67, SD = 14.26) in the control group. Oral jaw behaviors were assessed in the mild, moderate, and severe TMD+bruxing groups, and in the corresponding control group. It was found that the prevalence of oral jaw behaviors was higher in the TMD+bruxing behavior group as compared to the control. Hence, concomitant oral jaw behaviors predominated in bruxers and increased with its severity. The data reinforce the need to assess TMD patients in terms of the presence of bruxism, its severity, and concomitant oral jaw habits. Such approach will enable the clinician to have better understanding about the role of these behaviors in TMD. Epidemiological data was also provided regarding jutting the jaw forward (a rarely-described oral jaw habit) in a relatively large sample of TMD+bruxing patients, suggesting a more clinical intervention in children and adolescents. This study is the first to document the prevalence of specific oral jaw habits in a relatively large sample of TMD+bruxing behavior classified by degree of severity. Results suggest that TMD+bruxing patients may present many other additional oral jaw habits which may concur to increase masticatory muscle activity thus leading to TMD signs and symptoms. Factors responsible for the increased frequency of oral jaw habits with the severity of bruxism behavior remain unknown and therefore further studies are needed.

Adolescent↗
PubMed2001

Intimate partner violence, dependence symptoms and social consequences from drinking among white, black and Hispanic couples in the United States.

This study estimates the association of intimate partner violence (IPV) and alcohol-dependence symptoms, social consequences from drinking, and drug use among white, black, and Hispanic couples. A probability sample of 555 white, 358 black, and 527 Hispanic couples in the U.S. household population was interviewed in 1995. The response rate was 85%. Bivariate analysis indicates that most problem status variables are associated with increased rates of male-to-female (MFPV) and female-to-male (FMPV) partner violence. Logistic regression analyses showed that predictors of MFPV and FMPV vary by ethnicity.

Adult↗
PubMed2001

Keratinocyte growth factor attenuates hydrostatic pulmonary edema in an isolated, perfused rat lung model.

Hydrostatic pulmonary edema is a common complication of congestive heart failure, resulting in substantial morbidity and mortality. Keratinocyte growth factor (KGF) is a mitogen for type II alveolar epithelial and microvascular cells. We utilized the isolated perfused rat lung model to produce hydrostatic pulmonary edema by varying the left atrial and pulmonary capillary pressure. Pretreatment with KGF attenuated hydrostatic edema formation. This was demonstrated by lower wet-to-dry lung weight ratios, histological evidence of less alveolar edema formation, and reduced alveolar accumulation of intravascularly administered FITC-labeled large-molecular-weight dextran in rats pretreated with KGF. Thus KGF attenuates injury in this ex vivo model of hydrostatic pulmonary edema via mechanisms that prevent increases in alveolar-capillary permeability.

Animals↗
PubMed2001

Interleukin-17 and lung host defense against Klebsiella pneumoniae infection.

Bacterial pneumonia remains an important cause of morbidity and mortality worldwide, especially in immune-compromised patients. Cytokines and chemokines are critical molecules expressed in response to invading pathogens and are necessary for normal lung bacterial host defenses. Here we show that interleukin (IL)-17, a novel cytokine produced largely by CD4+ T cells, is produced in a compartmentalized fashion in the lung after challenge with Klebsiella pneumoniae. Moreover, overexpression of IL-17 in the pulmonary compartment using a recombinant adenovirus encoding murine IL-17 (AdIL-17) resulted in the local induction of tumor necrosis factor-alpha, IL-1beta, macrophage inflammatory protein-2, and granulocyte colony-stimulating factor (G-CSF); augmented polymorphonuclear leukocyte recruitment; and enhanced bacterial clearance and survival after challenge with K. pneumoniae. However, simultaneous treatment with AdIL-17 provided no survival benefit after intranasal K. pneumoniae challenge. These data show that IL-17 may have a role in priming for enhanced chemokine and G-CSF production in the context of lung infection and that optimally timed gene therapy with IL-17 may augment host defense against bacterial pneumonia.

Animals↗
PubMed2001

Filgrastim in patients with pneumonia and severe sepsis or septic shock.

STUDY OBJECTIVES: Evaluate the safety of filgrastim (recombinant methionyl human granulocyte colony-stimulating factor) administration, combined with standard therapy, in patients with pneumonia and either septic shock or severe sepsis who were receiving mechanical ventilation. DESIGN: Multicenter, double-blind, randomized, placebo-controlled study. SETTING: ICU, multicenter. PATIENTS: Eighteen patients with pneumonia and hypotension, or in the absence of shock, two or more end-organ dysfunctions, were enrolled and treated. Baseline acute physiology and chronic health evaluation II scores and median age for the filgrastim (n = 12) and placebo (n = 6) groups were 25.0 and 49.5 years and 31.5 and 56.5 years, respectively. INTERVENTION: Filgrastim (300 microg) or placebo was administered IV daily for up to 5 days. MEASUREMENTS AND RESULTS: Study end points included safety; biological response, including endogenous cytokine levels, endotoxin levels, and neutrophil counts; and mortality. Cytokine and endotoxin levels were highly variable in both groups. By day 29, 3 of 12 filgrastim-treated patients and 4 of 6 placebo-treated patients had died. There were no differences in types and occurrences of adverse events, including ARDS, or in outcome between the two groups. Three of four placebo-treated patients had persistent bacterial growth on bronchoscopy repeated after 48 h compared with 2 of 10 filgrastim-treated patients. CONCLUSION: Filgrastim appeared to be well tolerated in this population of patients with pneumonia and severe sepsis or septic shock. Larger studies to determine the benefit of filgrastim in patients with pneumonia and sepsis or organ dysfunction are warranted.

Adult↗
PubMed2001

Novel nonantibiotic therapies for pneumonia: cytokines and host defense.

Effective host defense against bacterial infection is dependent on the activation and recruitment of phagocytic cells. The initiation, maintenance, and resolution of this inflammatory response in the setting of bacterial pneumonia is dependent on the expression of cytokines. As the complexities of the host-pathogen interaction are further dissected and unraveled, immunologic manipulation of cytokine expression will likely become an important adjuvant therapy in the treatment of serious lung infections.

Animals↗
PubMed2001

Inhibition of hematopoietic progenitor cell proliferation by ethanol in human immunodeficiency virus type 1 tat-expressing transgenic mice.

BACKGROUND: A number of hematological abnormalities are associated with both human immunodeficiency virus type 1 (HIV-1) infection and alcohol abuse. There is little information on how alcohol abuse might further influence the survival and growth of hematopoietic progenitors in HIV-infected individuals in the presence of immune system abnormalities and anti-HIV drugs. Because there is evidence that viral transactivator Tat itself can induce hematopoietic suppression, in this study we examined the role of ethanol as a cofactor in transgenic mice that expressed HIV-1 Tat protein. METHODS: Tat transgenic mice and nontransgenic littermates were given ethanol (20% v/v) and the anti-HIV drug 3'-azido-3'-deoxythymidine (AZT; 1 mg/ml) in drinking water. Immunosuppression in mice was induced by weekly intraperitoneal injections of anti-CD4 antibody. Hematopoiesis was examined by erythroid colony forming unit (CFU-E) and granulocyte/macrophage colony-forming unit (CFU-GM) assays of the bone marrow progenitor cells. RESULTS: Administration of ethanol for 7 weeks resulted in a 50% decrease in the proliferative capacity of CFU-E- and CFU-GM-derived progenitors from transgenic mice compared with that of ethanol-treated nontransgenic controls. Similar decreases also were observed in transgenic mice treated with AZT or a combination of AZT and ethanol. Furthermore, ethanol and AZT were significantly more toxic to the granulopoietic progenitors (40-50% inhibition) than to the erythropoietic progenitors (10-20% inhibition) in Tat transgenic mice. Although a 10 day exposure of Tat transgenic and nontransgenic mice to a combination of ethanol and AZT had no suppressive effect on the erythropoietic and granulopoietic progenitor cells, there was a marked decrease (40-60%) in CFU-GM in mice made immunodeficient by CD4+ T-lymphocyte depletion. The ethanol-treated Tat transgenic mice but not the nontransgenic litter-mates also showed a significant decrease (25%) in CFU-GM. CONCLUSION: Our in vivo study strongly suggests that ethanol ingestion in HIV-1-infected individuals, particularly those on antiretroviral drugs, might increase bone marrow toxicity and contribute to HIV-1-associated hematopoietic impairment.

Animals↗
PubMed2001

Implications for dental education of a dental school-initiated practice research network.

The Case Western Reserve University (CWRU) School of Dentistry has organized a research network of 210 general dentists in northern Ohio. Seventeen of these dentists have volunteered to serve on a steering committee, for the purpose of generating research questions and helping with network organization. To enable the practitioners to investigate questions of interest in their practices, faculty in the CWRU schools of Dentistry and Medicine provide consultation to network dentists, as needed, with regard to research design, implementation, and analysis. In turn, the network serves as a resource for the dental school, facilitating faculty development, encouraging the development of new research programs, and providing an opportunity for students throughout the university to become involved in dental practice research. To date, faculty members have initiated studies of dental practice that include a survey of dentists' attitudes toward tobacco, a weekly return caries study, and a direct observation study of general dental practice. The network provides a research "laboratory" for the dental school, enabling clinical faculty to participate in research concerning dental practice. It has also stimulated a major re-examination of several curriculum elements in the school.

Adult↗
PubMed2000

A randomized controlled trial of filgrastim for the treatment of hospitalized patients with multilobar pneumonia.

This study assessed the safety and efficacy of filgrastim (r-metHuG-CSF [recombinant human methionine granulocyte colony-stimulating factor]), when combined with intravenous (IV) antibiotics, in the treatment of hospitalized adult patients with multilobar community-acquired pneumonia (CAP). Four hundred eighty patients were randomized to receive placebo (n=243) or filgrastim 300 microg/day (n=237), in addition to standard therapy. Treatment with study drug was continued for 10 days, until the peak white blood cell (WBC) count reached 75x109/L, until discharge from the hospital, until death, or until IV antibiotics were discontinued. Study-related observations continued through day 29. Filgrastim increased WBC counts (baseline median, 13.3x109/L; median peak, 43. 8x109/L). The 2 treatment groups were not statistically different with respect to the study end points; however, there was a trend toward reduction of mortality in patients with pneumococcal bacteremia. Although further studies will be required to validate this observation, filgrastim was safe and well tolerated when administered to patients with multilobar CAP.

Adult↗
PubMed2000

Cloning and characterization of a Na+-driven anion exchanger (NDAE1). A new bicarbonate transporter.

Regulation of intra- and extracellular ion activities (e.g. H(+), Cl(-), Na(+)) is key to normal function of the central nervous system, digestive tract, respiratory tract, and urinary system. With our cloning of an electrogenic Na(+)/HCO(3)(-) cotransporter (NBC), we found that NBC and the anion exchangers form a bicarbonate transporter superfamily. Functionally three other HCO(3)(-) transporters are known: a neutral Na(+)/ HCO(3)(-) cotransporter, a K(+)/ HCO(3)(-) cotransporter, and a Na(+)-dependent Cl(-)-HCO(3)(-) exchanger. We report the cloning and characterization of a Na(+)-coupled Cl(-)-HCO(3)(-) exchanger and a physiologically unique bicarbonate transporter superfamily member. This Drosophila cDNA encodes a 1030-amino acid membrane protein with both sequence homology and predicted topology similar to the anion exchangers and NBCs. The mRNA is expressed throughout Drosophila development and is prominent in the central nervous system. When expressed in Xenopus oocytes, this membrane protein mediates the transport of Cl(-), Na(+), H(+), and HCO(3)(-) but does not require HCO(3)(-). Transport is blocked by the stilbene 4,4'-diisothiocyanodihydrostilbene- 2, 2'-disulfonates and may not be strictly electroneutral. Our functional data suggest this Na(+) driven anion exchanger (NDAE1) is responsible for the Na(+)-dependent Cl(-)-HCO(3)(-) exchange activity characterized in neurons, kidney, and fibroblasts. NDAE1 may be generally important for fly development, because disruption of this gene is apparently lethal to the Drosophila larva.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed2000

Immune modulation in the treatment of respiratory infection.

The limitations of currently available treatment for severe respiratory infection are demonstrated by the relatively fixed mortality associated with these infections despite advances in nutrition, vaccines, antibiotics, and critical care. This might be due in part to the changing spectrum of pathogens and development of drug resistance. Cytokines are potent molecules that function as growth factors and orchestrate both innate and adaptive immune responses. Several of these factors have entered the clinical arena to support or augment the immune response. Moreover, the use of cytokines has recently been expanded to patients without an overtly defective immune system but who have either significant infection or infection with drug resistant organisms. The use of cytokines as adjuvants in the treatment of respiratory infections is reviewed.

Adjuvants, Immunologic↗
PubMed2000

Requirement of endogenous stem cell factor and granulocyte-colony-stimulating factor for IL-17-mediated granulopoiesis.

IL-17 is a novel, CD4+ T cell-restricted cytokine. In vivo, it stimulates hematopoiesis and causes neutrophilia consisting of mature granulocytes. In this study, we show that IL-17-mediated granulopoiesis requires G-CSF release and the presence or induction of the transmembrane form of stem cell factor (SCF) for optimal granulopoiesis. However, IL-17 also protects mice from G-CSF neutralization-induced neutropenia. G-CSF neutralization completely reversed IL-17-induced BM progenitor expansion, whereas splenic CFU-GM/CFU-granulocyte-erythrocyte-megakaryocyte-monocyte was only reduced by 50% in both Sl/Sld and littermate control mice. Thus, there remained a significant SCF/G-CSF-independent effect of IL-17 on splenic granulopoiesis, resulting in a preservation of mature circulating granulocytes. IL-17 is a cytokine that potentially interconnects lymphocytic and myeloid host defense and may have potential for therapeutic development.

3T3 Cells↗
PubMed2000

A phase I trial of solubilized DR2:MBP84-102 (AG284) in multiple sclerosis.

OBJECTIVE: To assess the safety, tolerability, and biologic and clinical activity of a solubilized complex comprised of human leukocyte antigen-DR2 with myelin basic protein84-102 (AG284)in patients with secondary progressive MS. BACKGROUND: Soluble species-specific major histocompatibility complex myelin basic protein91-103 complexes ameliorate disease in a dose-dependent manner when administered to SJL/J mice with chronic relapsing experimental allergic encephalomyelitis. Preincubation with AG284 reduces the proliferative response of a DR2-restricted, myelin basic protein84-102-reactive T cell clone, derived from a MS patient, to myelin basic protein84-102 in the presence of autologous antigen-presenting cells. METHODS: Thirty-three patients with secondary progressive MS were randomly assigned to receive three alternate day IV doses of AG284 or placebo in a double-masked dose escalation study. The primary outcome was safety and tolerability. Secondary outcomes included a comparison of pre- and post-treatment gadolinium-enhanced brain MRI activity, Kurtzke Expanded Disability Status Scale, and Nine Hole Peg Test scores. RESULTS: The frequency of adverse events was similar in the AG284 and placebo recipients. No significant treatment effect was detected by Expanded Disability Status Scale, Nine Hole Peg Test, or number of new gadolinium-enhancing MRI lesions. CONCLUSIONS: AG284 as administered during this study was safe and well tolerated. Further studies are warranted to determine the biologic activity and clinical efficacy of this potential treatment for MS.

Adult↗
PubMed2000

Orthotopic human lung carcinoma xenografts in BALB/c mice immunosuppressed with anti-CD4 monoclonal antibodies and chronic alcohol consumption.

BACKGROUND: The role of the immune system in the surveillance of the body for cancer cells is well established. Human tumor cells do not survive in mice with intact immune systems, but they propagate in athymic nude mice. Presumably, the lack of a thymus gland and consequent loss of T lymphocytes results in a seriously compromised immune system without adequate cell-mediated immunity and tumor surveillance. In patients infected with the human immunodeficiency virus (HIV), a progressive loss of cell-mediated immunity is associated with the development of malignancies and opportunistic infections. This effect may be exacerbated in patients who chronically consume alcohol. METHODS: Normal and alcoholic BALB/c mice were treated with a monoclonal antibody to deplete CD4(+) lymphocytes before orthotopic implantation of human lung adenocarcinoma xenografts. Tumor volume and weight were measured and compared between groups. RESULTS: The authors' data show that a single treatment of anti-CD4 antibody causes almost complete depletion of CD4(+) lymphocytes and permits the formation of large intrapulmonary human nonsmall lung carcinoma xenografts in 100% of treated mice. All control animals injected with heat-denatured antibody failed to produce tumors. Chronic alcohol consumption by CD4-depleted mice resulted in larger tumors, compared with mice that did not receive ethanol in their diet (P = 0.05). CONCLUSIONS: Depletion of CD4(+) lymphocytes allows for the orthotopic growth of human lung adenocarcinoma xenografts in BALB/c mice. Furthermore, the consumption of alcohol reduces the ability of the impaired immune system to reject tumors.

Adenocarcinoma↗
PubMed2000

Very selective suppression pulses for clinical MRSI studies of brain and prostate cancer.

Focal three-dimensional magnetic resonance spectroscopic imaging (3D MRSI) methods based on conventional point resolved spectroscopy (PRESS) localization are compromised by the geometric restrictions in volume prescription and by chemical shift registration errors. Outer volume saturation (OVS) pulses have been applied to address the geometric limits, but conventional OVS pulses do little to overcome chemical shift registration error, are not particularly selective, and often leave substantial signals that can degrade the spectra of interest. In this paper, an optimized sequence of quadratic phase pulses is introduced to provide very selective spatial suppression with improved B1 and T1 insensitivity. This method was then validated in volunteer studies and in clinical 3D MRSI exams of brain tumors and prostate cancer.

Brain Neoplasms↗
PubMed2000

Inhibition of TNF-alpha processing and TACE-mediated ectodomain shedding by ethanol.

Alcohol (EtOH) is a well-documented immunosuppressant. Acute EtOH-induced immunosuppression is partially due to suppression of tumor necrosis factor alpha (TNF-alpha) secretion. We investigated the mechanism of acute EtOH-induced TNF-alpha suppression in two monocytic cell lines, Mono Mac 6 and DRM. EtOH inhibited TNF-alpha secretion in a dose-dependent manner. However, TNF-alpha transcription was not affected by EtOH. Enzyme-linked immunosorbent assay and confocal microscopy showed that EtOH treatment increased cell-associated TNF-alpha. Ectodomain shedding of TNF-alpha from the cell surface is mediated by TNF-alpha converting enzyme (TACE). In contrast with TNF-alpha, EtOH did not inhibit interleukin-8 (IL-8) secretion, which does not require shedding. Furthermore, TNF p75 receptor shedding, a biomarker for TACE activity, was inhibited by EtOH in both cell lines. EtOH also inhibited TNF p75 receptor shedding in TACE-reconstituted fibroblasts, suggesting that EtOH inhibits the shedding process. These data show that acute EtOH exposure can posttranscriptionally suppress TNF-alpha production, resulting in specific defects in immune defense.

ADAM Proteins↗