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J Pappas

Publications and source records attributed to J Pappas.

At least 19 recordsLinked to original sources
PubMed2002

Biexponential T2 relaxation time analysis of the brain: correlation with magnetization transfer ratio.

RATIONALE AND OBJECTIVES: To measure T2 relaxation times of normal white and gray matter using a novel CPMG sequence and investigate if any correlation exists between magnetization transfer ratio (MTR) and T2 relaxation-related parameters. MATERIALS AND METHODS: Seventeen normal volunteers participated on this study. A single-slice 32-echo sequence was used to calculate the T2 relaxation time of frontal and occipital white matter and cortical gray matter. T2 relaxation analysis included monoexponential and biexponential fitting whereas an F test was used to determine if biexponential fitting was statistically more accurate than monoexponential fitting. Short and long T2 constants were calculated as well as the signal fractions of each pool. MTR calculations were based on a three-dimensional gradient echo (3D FFE) proton density weighted sequence with and without an on-resonance composite prepulse. MTR and T2 relaxation times were calculated and linear regression analysis was applied. RESULTS: Biexponential fitting was more accurate comparing with monoexponential fitting in all WM and GM regions (F > 2.47, P < 0.01). Mean values of short T2 constant for frontal white matter (fWM), occipital white matter (oWM) and gray matter (GM) were 8.10, 9.36, and 22.23 milliseconds, respectively, whereas the mean values of long T2 constant were 85.1, 93.02, and 118.72 milliseconds, respectively. Mean restricted water percentages (RWP)-corresponding to the signal fraction of the protons with short T2-for the fWM, oWM, and GM were 22.01%, 23.36%, and 18.7%. Mean free water percentages (FWP)-corresponding to the signal fraction of the protons with long T2-for the fWM, oWM and GM were 77.99%, 76.64%, and 81.3%. Mean MTR values for fWM, oWM and GM were 68.4%, 68.2%, and 61.3%, respectively. No significant correlation was found in fWM and oWM between MTR and RWP, short and long T2 components while a moderate correlation existed in GM between MTR and RWP (r = 0.57; P = 0.02), MTR and short T2 component (r = -0.69; P = 0.004) and MTR and long T2 component (r = -0.62; P = 0.012). CONCLUSIONS: Two proton pools with different T2 decay characteristics can be separated in normal gray and white matter when using a multiecho sequence with short echo spacing. MTR and T2 relaxation times were significantly correlated in gray matter and the combination of both types of measurements may be helpful in studying myelin related disorders.

Adult↗
PubMed2001

Tumor necrosis factor-alpha, interleukin-6, and nitric oxide in sterile ascitic fluid and serum from patients with cirrhosis who subsequently develop ascitic fluid infection.

Ascitic fluid infection probably results from repeated episodes of bacteremia and seeding of ascitic fluid. The outcome of these episodes of colonization is probably a function of serum and ascitic fluid defense mechanisms and the virulence of the organism. Patients who develop spontaneous bacterial peritonitis may have serum and ascitic fluid characteristics that are different from those who do not develop infection. We prospectively collected serum and ascitic fluid specimens at the time of admission from patients with sterile cirrhotic ascites, and tested these specimens for interleukin-6, tumor necrosis factor-alpha, and nitric oxide and compared these results as well as other characteristics of patients who did not develop infection to those who did. An elevated baseline serum tumor necrosis factor-alpha as well as an increased proportion of polymorphonuclear leukocytes in sterile ascitic fluid from patients who subsequently developed infection probably represent a subclinical activation of defense mechanisms from prior silent colonizations with bacteria.

Adult↗
PubMed2001

Composite effects of group drumming music therapy on modulation of neuroendocrine-immune parameters in normal subjects.

CONTEXT: Drum circles have been part of healing rituals in many cultures throughout the world since antiquity. Although drum circles are gaining increased interest as a complementary therapeutic strategy in the traditional medical arena, limited scientific data documenting biological benefits associated with percussion activities exist. OBJECTIVE: To determine the role of group-drumming music therapy as a composite activity with potential for alteration of stress-related hormones and enhancement of specific immunologic measures associated with natural killer cell activity and cell-mediated immunity. DESIGN: A single trial experimental intervention with control groups. SETTING: The Mind-Body Wellness Center, an outpatient medical facility in Meadville, Pa. PARTICIPANTS: A total of 111 age- and sex-matched volunteer subjects (55 men and 56 women, with a mean age of 30.4 years) were recruited. INTERVENTION: Six preliminary supervised groups were studied using various control and experimental paradigms designed to separate drumming components for the ultimate determination of a single experimental model, including 2 control groups (resting and listening) as well as 4 group-drumming experimental models (basic, impact, shamanic, and composite). The composite drumming group using a music therapy protocol was selected based on preliminary statistical analysis, which demonstrated immune modulation in a direction opposite to that expected with the classical stress response. The final experimental design included the original composite drumming group plus 50 additional age- and sex-matched volunteer subjects who were randomly assigned to participate in group drumming or control sessions. MAIN OUTCOME MEASURES: Pre- and postintervention measurements of plasma cortisol, plasma dehydroepiandrosterone, plasma dehydroepiandrosterone-to-cortisol ratio, natural killer cell activity, lymphokine-activated killer cell activity, plasma interleukin-2, plasma interferon-gamma, the Beck Anxiety Inventory, and the Beck Depression Inventory II. RESULTS: Group drumming resulted in increased dehydroepiandrosterone-to-cortisol ratios, increased natural killer cell activity, and increased lymphokine-activated killer cell activity without alteration in plasma interleukin 2 or interferon-gamma, or in the Beck Anxiety Inventory and the Beck Depression Inventory II. CONCLUSIONS: Drumming is a complex composite intervention with the potential to modulate specific neuroendocrine and neuroimmune parameters in a direction opposite to that expected with the classic stress response.

Adult↗
PubMed1998

Differential expression of Met/hepatocyte growth factor receptor in subtypes of non-small cell lung cancers.

Hepatocyte growth factor (HGF)/scatter factor (SF) is a multifunctional factor that stimulates epithelial cell motility, invasion and morphogenesis. Its receptor is a transmembrane tyrosine kinase encoded by the Met proto-oncogene. Several studies have suggested a possible role for HGF/Met in tumor development and progression. To investigate the potential roles of Met in human lung cancer biology, we have studied the mRNA and protein expression of Met in normal lung tissue, primary non-small cell lung carcinoma (NSCLC), and NSCLC cell lines. The results indicated a differential pattern of Met expression among various subtypes of NSCLC. The majority of squamous cell carcinoma (SQCC), either in vivo or in vitro, expressed Met mRNA and its protein product at levels much lower than or similar to normal lung tissue or bronchial epithelium. Moreover, SQCC characteristically over-expressed a variant Met mRNA which corresponds to a 5' partially deleted transcript produced by alternative splicing. In contrast, the expression of Met mRNA and its protein product in adenocarcinoma (ADC) and large cell undifferentiated carcinoma were more heterogeneous. Overexpression was demonstrated in approximately 35% and 20% of these subtypes of NSCLC, respectively. Among ADC, intermediate to high levels of Met immunoreactivity correlated with greater degree of tumor differentiation. Furthermore, an accentuation of Met immunoreactivity was often noted in cancer cells at the advancing edge of tumors. These findings support a role for Met in lung cancer cell invasion and differentiation in vivo, but its expression and functions may be modified by the differentiation phenotype of the tumor cells.

Adenocarcinoma↗
PubMed1998

Implementation and evaluation of Nursing Interventions Classification and Nursing Outcomes Classification in a patient education plan.

Nursing Interventions Classification (NIC) and Nursing Outcomes Classification (NOC) are recognized examples of standardized nursing languages used to describe the contribution nursing makes to patient care. Columbus Regional Hospital nursing leadership recognized the need to use standardized nursing interventions and nursing-sensitive patient outcomes to describe the unique contribution nursing makes to patient education. In collaboration with the University of Iowa, NIC/NOC languages were implemented in the development of a patient education plan for a clinical pathway population.

Critical Pathways↗
PubMed1998

Amplification of T-cell receptor alpha- and beta-chain transcripts from mouse spleen lymphocytes by the nonpalindromic adaptor-polymerase chain reaction.

We employed the nonpalindromic adaptor-PCR (NPA-PCR) method to amplify T-cell receptor (TCR) alpha- and beta-chain transcripts from the spleen of normal SJL mice. The NPA-PCR method has been specifically designed for the amplification of transcripts with variable or unknown 5' ends, such as TCRs and immunoglobulins (Ig). This method has certain distinct advantages over existing two-sided PCR methods for the amplification of TCR transcripts. Two NPA-PCR amplifications are sufficient to amplify all the TCR transcripts (one for the alpha-chain and another one for the beta-chain). Amplification of TCR transcripts by classical two-sided PCR requires a minimum of 45 amplification reactions for the murine TCR (20 for the V alpha families and 25 for the V beta families), using 45 different V-family-specific amplification primers. cDNA was synthesized from spleen RNA, using oligonucleotides complementary to sequences of either the murine TCR C alpha or C beta regions. The NotI restriction site was conjugated to these primers and therefore, a NotI restriction site was incorporated at the 3' end of the cDNA. A double-stranded nonpalindromic adaptor (EcoRI-XmnI strand and XmnI G strand, which are complementary to each other) was ligated onto both ends of the double-stranded cDNA. The adaptor was removed from the 3' end by NotI nuclease digestion whereas the adaptor was retained at the 5' end. Two rounds of PCR amplification were carried out. In the first, the EcoRI-XmnI adaptor was used as 5' end amplification primer; an antisense C region primer, designated mC alpha 2 or mC beta 2 (for the alpha- and beta-chain, respectively), was used as 3' amplification primer. In the second round of PCR amplification the same 5' end primer and a 3' end antisense primer, designated mC alpha 1 or mC beta 1, were used. These mC alpha 1 and mC beta 1 primers are located 5' to the mC alpha 2/mC beta 2 primers that were used for the first amplification. The amplified transcripts were cloned. Colonies were screened using a 32P-labeled probe, either C alpha or C beta, located 5' to those used for the last amplification and many positive clones were isolated and sequenced. All clones were unique when compared to each other, as anticipated for polyclonal T-cell populations. Comparison of the sequences obtained to those in the GENBANK/EMBL database revealed that they were typical of mouse alpha- or beta-chain TCR. With the exception of two beta-chain TCR transcripts, all the sequences shown here (36 alpha-chain and 20 beta-beta chain) have not been previously reported to the GENBANK/EMBL database.

Amino Acid Sequence↗
PubMed1998

A software architecture to support a large-scale, multi-tier clinical information system.

A robust software architecture is necessary to support a large-scale multi-tier clinical information system. This paper describes our mechanism for enterprise distribution of applications and support files, the consolidation of data-access functions and system utilities stored on the data access tier, and an application framework which implements a coherent clinical computing environment. The software architecture and systems described in this paper have been robust through pilot testing of our applications at Massachusetts General Hospital.

Computer Security↗
PubMed1997

Cholera toxin triggers apoptosis in human lung cancer cell lines.

Cholera toxin (ChT) inhibits signals generated by multiple growth factors in human lung cancer cells, resulting in cell growth inhibition. We now report that ChT triggers apoptosis as shown by DNA fragmentation and activation of caspases cleaving poly(ADP-ribose) polymerase and lamin B. Apoptosis induced by ChT in a small cell lung cancer cell line is not affected by manipulations of intracellular cAMP through preincubation with isobutylmethylxanthine but can be modestly increased through inhibition of protein kinase C with chelerythrine. Thus, apoptosis is actively suppressed in lung cancer cells by a ChT-sensitive-growth regulatory pathway, and these observations may have significant implications in the development of novel strategies for lung cancer treatment.

1-Methyl-3-isobutylxanthine↗
PubMed1997

MR cholangiopancreatography at 0.5 T with a 3D inversion recovery turbo-spin-echo sequence.

The objective of this study was to assess the diagnostic value of magnetic resonance cholangiopancreatography (MRCP) at 0.5 T. The MRCP technique was performed in 28 patients with symptomatology referrable to the biliary system. A three-dimensional (3D) inversion recovery turbo-spin-echo (TSE) sequence was used to create 3D reconstructions of the bile ducts. Dilation of the biliary tree or pancreatic duct in 23 patients due to tumor, calculi, or strictures was depicted with excellent contrast resolution. The approximate level of obstruction and all calculi were accurately predicted by MRCP. In another 3 patients no cause was found for the biliary dilatation. In the last 2 cases no abnormalities were found by either MRCP or endoscopic retrograde cholangiopancreatography (ERCP). The MRCP technique at 0.5 T is an accurate method for the assessment of pathology of the biliary tree.

Biliary Tract Diseases↗
PubMed1997

Infarction of the corpus callosum: computed tomography and magnetic resonance imaging.

OBJECTIVE: To describe the computed tomography (CT) and magnetic resonance (MR) features of corpus callosum (CC) infarctions. METHODS: We reviewed retrospectively 352 consecutive cranial CT and MR scans showing cerebral infarcts. Involvement of the CC was identified in 28 patients. RESULTS: Infarctions of the CC were diffuse (n = 3) or focal (n = 25). The former were seen in the setting of diffuse cerebral ischemia secondary to cardiopulmonary arrest or status epilepticus. The latter were divided into those affecting predominantly the genu, body or splenium. The most common location of the insult was the splenium (n = 13), followed by the body (n = 6) and genu (n = 3). In the remaining three patients combined genu/body infarctions were seen. CONCLUSION: Infarction of the CC may be more common than previously thought and is most often the result of cerebral embolism. MR is better suited than CT for the detection of vascular lesions of the CC.

Adult↗
PubMed1997

Acquired CD40-ligand deficiency in chronic lymphocytic leukemia.

Patients with B-cell chronic lymphocytic leukemia (CLL) acquire an immunodeficiency with many characteristics similar to those of persons with inherited defects in the gene encoding the CD40-ligand (CD154). We found that the blood and splenic CD4+ T cells of patients with CLL failed to express surface CD154 after CD3 ligation. However, using an enzyme-linked immunosorbent assay (ELISA)-based quantitative competitive polymerase chain reaction (PCR), we noted that CD3 ligation could induce such T cells to express CD154 messenger RNA at levels similar to that of CD3-activated T cells from normal donors. Moreover, addition of increasing numbers of CLL B cells to activated normal donor T cells rapidly resulted in progressively greater down-modulation of CD154. Such down-modulation of CD154 could be blocked by addition of CD40 monoclonal antibody to cultures in vitro. We propose that leukemia cell-mediated down-modulation of CD154 on activated T cells accounts for some of the acquired immune defects of patients with CLL.

Base Sequence↗
PubMed1996

Growth factor expression and effects of amrinone in monocrotaline-induced pulmonary hypertension in rats.

Platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) have been implicated in myointimal proliferative arteriopathy, a lesion seen in monocrotaline-induced pulmonary hypertension (MIPH). The purpose of this study was to examine the expression of PDGF and bFGF in the lungs of rats given monocrotaline and to examine the effects of amrinone on the hearts and lungs of these rats. Twenty-four 26-day-old rats were randomized to receive either monocrotaline (approximately 3.6 mg/kg/d) or no monocrotaline and concomitantly to receive either amrinone (100 mg/kg/d) or no amrinone for 21 days. Lungs were examined for immunohistochemical evidence of PDGF and bFGF, and hearts were examined for effects of pulmonary hypertension and amrinone. Immunohistochemical staining of lungs showed no evidence of PDGF except in bronchioles. bFGF staining was similar between groups (no monocrotaline 25%, monocrotaline 27%, monocrotaline and amrinone 22%), and the staining was confined to the arterial walls. Rats given monocrotaline showed significantly greater right ventricular (RV) weight (0.13 +/- 0.02 g versus 0.23 +/- 0.04 g [mean +/- SD], P < 0.001), right ventricular/left ventricular (RV/LV) weight ratio (0.29 +/- 0.06 versus 0.59 +/- 0.1, P < 0.001), and lung/body weight ratio (0.006 +/- 0.001 versus 0.01 +/- 0.003, P < 0.05) than controls. Rats given monocrotaline and amrinone were not significantly different from rats given only monocrotaline with regard to RV weight, RV/LV weight ratio, or lung/body weight ratio. We conclude that the vasculopathy seen in MIPH is not associated with the presence of PDGF or bFGF, suggesting that other growth factors may mediate this process. The course of MIPH is not altered by amrinone.

Amrinone↗
PubMed1996

Bone marrow lesions: evaluation with fat-suppression turbo spin echo MR imaging at 0.5 T.

The purpose of this study was the assessment of the diagnostic value of fat-suppression T2-weighted images for a variety of bone marrow lesions. We performed 40 studies of the axial or appendicular skeleton in 33 patients (age range 4-80 years) with neoplastic, inflammatory or traumatic lesions with a 0.5 T system (Gyroscan T5, Philips Medical Systems, Best, The Netherlands). Fat-suppression T2-weighted images [turbo spin echo (TSE) with spectral presaturation with inversion recovery (SPIR)] were obtained in addition to the routine T1-weighted SE and T2-weighted TSE sequences. Fat-suppression TSE T2-weighted images were better than standard TSE T2-weighted images in 25 studies. In 11 of them demonstration and characterization of the lesions (known from T1-weighted images) was possible only after fat suppression. In the other 14 patients demonstration of the full extent of the lesion especially to the nearby soft tissues was possible only after fat suppression. In 13 studies no advantage was conferred by SPIR, whereas in two instances T2-weighted images were better. Fat-suppression T2-weighted images are diagnostically useful in a variety of lesions of the musculoskeletal system, but their limitations should be known.

Adolescent↗
PubMed1996

Acute subarachnoid haemorrhage: detection with magnetic resonance imaging.

The purpose of this study was the evaluation of fluid attenuated turbo inversion recovery (FLAT TIRE) MR pulse sequence for detecting acute subarachnoid hemorrhage (SAH). Seven patients with SAH were studied within 6 days of ictus. Six of them underwent both CT and MRI and one MRI only. Pulse sequences included T1 spin echo (SE), PD and T2 turbo spin echo (TSE) and FLAT TIRE (TR/TI/TE = 6500/1800/140-180). All studies were performed on a 0.5 T system (Gyroscan T5, Philips Medical Systems). Simulated acute SAH was also studied with MRI. The FLAT TIRE sequence was better than the SE and TSE in all seven cases and better than CT in two cases. In two cases MRI was equivalent to CT, and in another two MRI underestimated the extent of SAH. The simulated acute SAH could be detected easily with the FLAT TIRE sequence, with difficulty on the T1 weighted images and not at all on the PD/T2 weighted images. The specific FLAT TIRE sequence used seems promising for the detection of acute SAH.

Acute Disease↗
PubMed1995

The third component of Xenopus complement: cDNA cloning, structural and functional analysis, and evidence for an alternate C3 transcript.

Although the third component of complement has been purified from two amphibian species, Xenopus laevis and the axolotl, only limited information is available about its primary structure in these species. We now present (a) 95% of the cDNA sequence encoding C3 from a Xenopus laevis/Xenopus gilli (Xenopus LG) hybrid (b) an analysis of the C3 convertase and factor I cleavage sites in Xenopus C3, and (c) evidence for an alternative form of C3. The Xenopus LG sequence has a 57% nucleotide and 52% amino acid sequence identity to human C3 and contains one potential N-glycosylation site in the beta-chain. The deduced amino acid sequence showed that the C3 convertase and factor I cleavage sites (Arg-Ser) are conserved in Xenopus C3 and protein sequencing of Xenopus C3 fragments fixed on zymosan during complement activation demonstrated that Xenopus C3 is indeed cleaved by C3 convertase and factor I at these sites. Our screening of a liver cDNA library identified an unusual C3 clone with a deletion of 2502 bp, suggesting the presence of a novel C3 transcript in Xenopus LG liver. The presence of this C3 transcript was confirmed by reverse transcription polymerase chain reaction using Xenopus LG liver mRNA and specific oligonucleotide probes. This transcript encoded a putative 102-kDa protein comprising the beta-chain of C3, together with the first 59 residues and the last 103 residues of the alpha-chain; it would therefore lack many of the ligand binding sites found in the intact alpha-chain. However, the molecule may be an analog of a truncated C3 molecule that is found in the serum of allergic dermatitis patients and acts as an inhibitor of eosinophil cytotoxicity and neutrophil adherence.

Amino Acid Sequence↗
PubMed1994

Intraarticular "pilon" fracture of the tibia.

Classification and treatment options for the management of tibial pilon fractures are reviewed. For comminuted and/or displaced fractures that require open reduction and internal fixation, a detailed description of the surgical technique, including indirect reduction techniques, is provided. Thirty-four pilon fractures (32 patients) treated during a period of five years (1984-1989) were reviewed. All were high-energy injuries (15 patients with multiple trauma) with Rüedi-Allgöwer Type II in 26 and Type III in eight. Eighteen (56%) were open fractures. Six fractures were treated with external fixation and the remaining 28 with open reduction and internal fixation. The patient follow-up examination period averaged 16.2 months (range, six to 38 months). Thirty (88%) fractures had united by 16 weeks (two delayed unions, one below knee amputation, and one plate breakage). In the 26 Type II fractures, functional grading found 17 excellent (65%) and six (23%) poor results. In the eight Type III fractures, there were four (50%) excellent and three (37%) poor results. Complications included one superficial pin-tract infection and two deep wound infections, both in Grade II open fractures.

Adult↗