Human T-cell lymphotropic virus (HTLV)-related endogenous sequence, HRES-1, encodes a 28-kDa protein: a possible autoantigen for HTLV-I gag-reactive autoantibodies

The presence of a human T-cell lymphotropic virus (HTLV)-related endogenous sequence, HRES-1, in the human genome has been documented. The HRES-1 genomic locus is transcriptionally active and contains open reading frames. Antibodies 232 and 233, specific for synthetic peptides pep14-24 and pep117-127, corresponding to two nonoverlapping HTLV-related regions in the longer open reading frame of HRES-1, recognize an identical 28-kDa protein in H9 human T cells. Thus, HRES-1 is a human endogenous retroviral sequence capable of protein expression. HRES-1/p28 is localized to the cytoplasm and nuclear bodies. While HTLV-I-specific antibodies react with HRES-1 peptides, antibody 233 cross-reacts with HTLV-I gag p24 protein. Three consecutive highly charged amino acid residues, Arg-Arg-Glu, present in both HRES-1 pep117-127 and HTLV-I gag p24 are likely to be the core of cross-reactive epitopes. The prevalence of antibodies to HRES-1 peptides pep14-24 and pep117-127 was determined in 65 normal blood donors and 146 patients with immunological disorders. Sera of patients with multiple sclerosis (19 out of 65, 29%), progressive systemic sclerosis (4 out of 17, 23%), systemic lupus erythematosus (4 out of 19, 21%), and Sjogren syndrome (2 out of 19, 10%) contained significantly higher HRES-1 peptide binding activity than sera of normal donors. Sera of patients with AIDS showed no specific binding to HRES-1 peptides. Nine of 30 HRES-1-seropositive patients showed immunoreactivity to HTLV-I gag p24. The data indicate that HRES-1/p28 may serve as an autoantigen eliciting autoantibodies cross-reactive with HTLV-I gag antigens.

Antibody reactivity with HBLV (HHV-6) in U.S. populations

500 sera representing healthy blood donors and a random representation of the U.S. population collected 10 years ago were screened by ELISA for antibody reactivity with purified, disrupted HBLV virions. In each group, the ELISA results were normally distributed with no evidence of bimodality. All sera were subsequently retested after preincubation of each with well-characterized preparations of disrupted HSB-2 cells or HBLV-infected HSB-2 cells. Sera showing significant levels of HBLV-specific neutralization (50% or more) were found in Minneapolis, Kansas City, and in a random population survey (81, 88 and 97% of donors, respectively). Mean ELISA test values were the same for all groups and for males and females within the same group. Sera from these normal donors reacted preferentially with viral antigens of 120 and 58 kDa by Western blot. In a hospital-based prevalence study, frequent IgM and IgG seroconversions were apparent among infants less than 1 year old, and mean ELISA test values reached the adult level before school age. Antigen preparations used in blocking experiments showed no competitive cross-reactivity with antisera against EBV, CMV, HSV, VZV, HIV, or adenovirus type 2 at levels which reduced antibody binding to HBLV by more than 90%. Antibody cross-reactivities towards HBLV and other human herpesviruses were assessed by cross-correlation of viral antibody titers against all of the viruses and by cross-absorptions of antisera against the other viruses with HBLV. In these experiments no antibody cross-reactivity between HBLV and other human herpesviruses were detected. The significance of these findings with respect to health/disease status is presently unknown. Further seroepidemiologic studies of quantitative levels of HBLV antibody reactivity to measure the age of primary infection and progressive changes in healthy and selected disease populations are needed to determine the risk of disease associated with HBLV infection.

Physical activity is related to lower levels of pain, fatigue and depression in individuals with spinal-cord injury: a correlational study

STUDY DESIGN

This was a prospective cross-sectional study for people with chronic spinal cord injury (SCI).

OBJECTIVES

To (1) evaluate the intensity level and nature of physical activity in community-dwelling individuals living with SCI, and (2) explore the relation between descriptive individual variables (for example, lesion level), secondary complications and participation in physical activity.

SETTING

Urban community setting.

METHODS

A total of 49 subjects with SCI who used a manual wheelchair for primary mode of mobility (mean years since injury, 11.8; mean age, 43.7 years; 67% paraplegia) completed the physical activity recall assessment for people with SCI (PARA-SCI).

RESULTS

Approximately 50% of reported physical activity among individuals with SCI is due to activities of daily living. The amount of physical activity was not related to lesion level, age, body mass index or waistline size. Greater heavy-intensity activity was related to lower levels of pain and fatigue and higher levels of self-efficacy, whereas higher amounts of mild-intensity activity and total activity were related to less depressive symptoms.

CONCLUSIONS

Activities of daily living are a large component for physical activity among individuals with SCI. It appears that greater physical activity is associated with less secondary complications (pain, fatigue and depression) in individuals with SCI.

Electrodeposited Defect Chemistry Superlattices

Nanometer-scale layered structures based on thallium(III) oxide were electrodeposited in a beaker at room temperature by pulsing the applied potential during deposition. The conducting metal oxide samples were superlattices, with layers as thin as 6.7 nanometers. The defect chemistry was a function of the applied overpotential: High overpotentials favored oxygen vacancies, whereas low overpotentials favored cation interstitials. The transition from one defect chemistry to another in this nonequilibrium process occurred in the same potential range (100 to 120 millivolts) in which the rate of the back electron transfer reaction became significant. The epitaxial structures have the high carrier density and low electronic dimensionality of high transition temperature superconductors.

Functional characterization of human NTRK2 mutations identified in patients with severe early-onset obesity

OBJECTIVE

The neurotrophin receptor TrkB has been implicated in the regulation of energy homeostasis in rodents. We have previously identified four rare missense mutations in the gene encoding TrkB, NTRK2, in 198 severely obese children with developmental delay. We have now undertaken a more detailed analysis of the in vitro functional consequences of the mutations identified: I98V, P660L, T821A and Y722C.

DESIGN

Wild-type and mutant TrkB receptor constructs were stably transfected into PC12 cells and the signaling responses to the endogenous ligand, brain-derived neurotrophic factor (BDNF), were examined by Western blotting of cell lysates. In the case of Y722C, PC12 cells stably expressing this mutant were studied for their ability to respond to BDNF by promoting neurite outgrowth and cell survival.

RESULTS

Further functional characterization of the previously reported Y722C TrkB mutation reveals impaired activation of mitogen-activated protein kinase, phospholipase C-gamma and Akt, as well as reduced BDNF-induced neurite outgrowth and cell survival in stably transfected PC12 cell lines. However, the signaling properties of I98V, P660L and T821A were all indistinguishable from wild type.

CONCLUSION

We provide further evidence for the impairment in signaling by Y722C and show that as well as a loss of signaling, this mutation affects the ability of TrkB to promote neurite outgrowth in response to BDNF. Thus, impaired hypothalamic neurogenesis may contribute to the severe hyperphagia and obesity seen in the individual harboring the Y722C variant. The other three rare TrkB variants do not show reduced autophosphorylation or impaired downstream signaling in vitro and, as yet, it is unclear whether these variants contribute to obesity in these patients.

Scanning Tunneling Microscopy of Electrodeposited Ceramic Superlattices

Cleaved cross sections of nanometer-scale ceramic superlattices fabricated from materials of the lead-thallium-oxygen system were imaged in the scanning tunneling microscope (STM). The apparent height differences between the layers were attributed to composition-dependent variations in local electrical properties. For a typical superlattice, the measured modulation wavelength was 10.6 nanometers by STM and 10.8 nanometers by x-ray diffraction. The apparent height profile for potentiostatically deposited superlattices was more square than that for galvanostatically deposited samples. These results suggest that the composition follows the applied potential more closely than it follows the applied current. The x-ray diffraction pattern of a superlattice produced under potential control had satellites out to the fourth order around the (420) Bragg reflection.

Effects of adenosine dialdehyde treatment on in vitro and in vivo stable protein methylation in HeLa cells

Adenosine dialdehyde (AdOx) is an indirect methyltransferase inhibitor broadly used in cell culture to accumulate methyl-accepting proteins in hypomethylated states for in vitro protein methylation analyses. In this study we included a translation inhibitor, cycloheximide, in the AdOx treatment of HeLa cells. The methyl-accepting proteins disappeared in the double treatment, indicating that they were most likely newly synthesized in the AdOx incubation period. AdOx treatment could also be used in combination with in vivo methylation, another technique frequently used to study protein methylation. AdOx treatment prior to in vivo methylation accumulated methyl-accepting proteins for the labeling reaction. The continued presence of AdOx in the in vivo labeling period decreased the methylation of the majority of in vivo methyl-accepting polypeptides. The level and pattern of the in vivo methylated polypeptides did not change after a 12-h chase, supporting the notion that the methylated polypeptide as well as the methyl groups on the modified polypeptides are stable. On the other hand, methylarginine-specific antibodies detected limited but consistent reduction of the methylarginine-containing proteins in AdOx-treated samples compared to the untreated ones. Thus, AdOx treatment probably only blocked a small fraction of stable protein methylation. Overall, it is likely that base-stable methylation are formed soon after the synthesis of the polypeptide and remain stable after the modification.

Phosphorylation of coat protein by protein kinase CK2 regulates cell-to-cell movement of Bamboo mosaic virus through modulating RNA binding

In this study, we investigated the fine regulation of cell-to-cell movement of Bamboo mosaic virus (BaMV). We report that the coat protein (CP) of BaMV is phosphorylated in planta at position serine 241 (S241), in a process involving Nicotiana benthamiana casein kinase 2α (NbCK2α). BaMV CP and NbCK2α colocalize at the plasmodesmata, suggesting that phosphorylation of BaMV may be involved in its movement. S241 was mutated to examine the effects of temporal and spatial dysregulation of phosphorylation on i) the interactions between CP and viral RNA and ii) the regulation of cell-to-cell movement. Replacement of S241 with alanine did not affect RNA binding affinity but moderately impaired cell-to-cell movement. A negative charge at position 241 reduced the ability of CP to bind RNA and severely interfered with cell-to-cell movement. Deletion of residues 240 to 242 increased the affinity of CP to viral RNA and dramatically impaired cell-to-cell movement. A threonine at position 241 changed the binding preference of CP toward genomic RNA and inhibited cell-to-cell movement. Together, these results reveal a fine regulatory mechanism for the cell-to-cell movement of BaMV, which involves the modulation of RNA binding affinity through appropriate phosphorylation of CP by NbCK2α.

Proteomic analysis of methylarginine-containing proteins in HeLa cells by two-dimensional gel electrophoresis and immunoblotting with a methylarginine-specific antibody

Protein arginine methylation is found in many nucleic acid binding proteins affecting numerous cellular functions. In this study we identified methylarginine-containing proteins in HeLa cell extracts by two-dimensional electrophoresis and immunoblotting with a methylarginine-specific antibody. Protein spots with matched protein stain and blotting signals were analyzed by mass spectrometry. The identities of 12 protein spots as 11 different proteins were suggested. Known methylarginine-containing proteins such as hnRNP A2/B1, hnRNP A1, hnRNP G and FUS were identified, indicating the feasibility of our approach. However, four highly abundant metabolic enzymes that might co-electrophorese with methylarginine-containing proteins were also identified. Other nucleic acid binding proteins hnRNP M, hnRNP I and NonO protein were identified. Recombinant hnRNP M and a peptide with the RGG sequence in hnRNP M could be further methylated in vitro. The immunoblotting results of immunoprecipitated hnRNP I and NonO protein are consistent with arginine methylation in both proteins. In this study we identified methylarginine-containing proteins in HeLa cells through proteomic approaches and the method is fast and robust for further applications.

Role of right hepatic lobectomy in the treatment of isolated right-sided hepatolithiasis

BACKGROUND

The role of right hepatic lobectomy is evaluated in the treatment of selected patients with isolated right-sided hepatolithiasis.

METHODS

During the past 7 years right hepatic lobectomy was performed in five patients who had isolated right-sided hepatolithiasis. The rationale and indications of this procedure are discussed. The efficacy of preoperative evaluations, the operative findings, and the operative results are analyzed.

RESULTS

All the patients were female with a mean age of 49.2 years (range, 33 to 63 years). The main symptoms were upper abdominal pain (n = 5), fever (n = 4), and jaundice (n = 2). The mean operative time was 166.4 minutes, and the mean blood loss was 880 ml. The complete stone clearance rate was 100%. No operative deaths occurred. Right subphrenic abscess with reactive pleural effusion developed in two patients. Echo-guided percutaneous drainage was applied to one patient, and no surgical intervention was needed. The mean follow-up period from the treatment was 13.4 months (range, 6 to 18 months). During the follow-up period no stone recurrence was found.

CONCLUSIONS

Right hepatic lobectomy is indicated in patients who have localized right-sided hepatolithiasis with irreversible biliary stricture involving the right hepatic duct, an atrophied right lobe of the liver, multiple cholangitic abscesses, or possible presence of cholangiocarcinoma. Preoperative evaluations, including cholangiography, abdominal ultrasonography, and computed tomography, are important for the accurate selection of patients and successful treatment.

A simple, secure and universal pancreaticojejunostomy following pancreaticoduodenectomy

Although the operative mortality of pancreaticoduodenal resection has decreased recently, the operative morbidity resulting from a leaking pancreatic anastomosis remains high. We described our experience in 50 consecutive cases with a simple, secure end to side pancreaticojejunostomy. We used a paediatric nasogastric tube in the pancreatic remnant duct as a temporary external pancreatic drain. There were 29 men and 21 women ranging from 12 to 84 years with a median age of 61 years. Forty-two patients underwent a standard Whipple procedure and eight a pylorus preserving pancreaticoduodenectomy. Average operating time was 270 minutes with a range of 170 to 480 minutes. The pancreaticojejunostomy could be constructed in a mean of 8 minutes. Intraoperative blood loss ranged from 150 to 3500 mL with a mean of 910 mL. Twenty-five patients (50%) received no blood transfusion. The consistency of the pancreatic remnant was hard in 12 patients (24%) and normal in 38 patients (76%). The pancreatic duct was dilated (> 4 mm) in 15 patients (30%). There was no operative mortality and only three (6.0%) minor leaks from the pancreatic anastomosis which healed spontaneously. It was difficult to determine if the leaks were related to the consistency of the pancreatic remnant, the size of the pancreatic duct, the amount of intraoperative blood loss, operating time, sex of the patient or experience of the surgeon, as there were only three leaks. We concluded that our technique for pancreaticojejunal anastomosis following pancreaticoduodenectomy was safe and applicable to, standard Whipple or pylorus preserving pancreaticoduodenectomy, small or dilated pancreatic ducts, normal or fibrotic pancreas.

Two key arginine residues in the coat protein of Bamboo mosaic virus differentially affect the accumulation of viral genomic and subgenomic RNAs

The interactions between viral RNAs and coat proteins (CPs) are critical for the efficient completion of infection cycles of RNA viruses. However, the specificity of the interactions between CPs and genomic or subgenomic RNAs remains poorly understood. In this study, Bamboo mosaic virus (BaMV) was used to analyse such interactions. Using reversible formaldehyde cross-linking and mass spectrometry, two regions in CP, each containing a basic amino acid (R99 and R227, respectively), were identified to bind directly to the 5' untranslated region of BaMV genomic RNA. Analyses of the alanine mutations of R99 and R227 revealed that the secondary structures of CP were not affected significantly, whereas the accumulation of BaMV genomic, but not subgenomic, RNA was severely decreased at 24 h post-inoculation in the inoculated protoplasts. In the absence of CP, the accumulation levels of genomic and subgenomic RNAs were decreased to 1.1%-1.5% and 33%-40% of that of the wild-type (wt), respectively, in inoculated leaves at 5 days post-inoculation (dpi). In contrast, in the presence of mutant CPs, the genomic RNAs remained about 1% of that of wt, whereas the subgenomic RNAs accumulated to at least 87%, suggesting that CP might increase the accumulation of subgenomic RNAs. The mutations also restricted viral movement and virion formation in Nicotiana benthamiana leaves at 5 dpi. These results demonstrate that R99 and R227 of CP play crucial roles in the accumulation, movement and virion formation of BaMV RNAs, and indicate that genomic and subgenomic RNAs interact differently with BaMV CP.

Factors related to primary bilateral spontaneous pneumothorax

OBJECTIVES

We studied the risk factors associated with primary bilateral spontaneous pneumothorax.

METHODS

From January 2001 to December 2002, 102 patients with primary spontaneous pneumothorax were reviewed and divided into two groups. Group A patients had primary spontaneous bilateral pneumothorax (PSBP; simultaneous or nonsimultaneous). Group B included patients with a primary spontaneous pneumothorax (PSP). We compared age, smoking habits, body weight, height, body mass index (BMI), and radiological findings between groups.

RESULTS

Twenty-four patients developed PSBP (24 %). The male-to-female ratio was 22 : 2 in group A and 73 : 5 in group B ( P = 0.106). Eleven group A patients (46 %) and 34 group B patients (44 %) were smokers ( P = 0.037). The mean BMI was 18.39 +/- 2.45 kg/m (2) in group A and 19.70 +/- 2.00 kg/m (2) in group B ( P = 0.009). High-resolution computed tomography revealed bilateral lung blebs or bullae in 63 % of group A patients and in 53 % of group B patients ( P = 0.724).

CONCLUSION

PSBP was significantly more frequent in patients with a lower BMI and among smokers. These patients require extended hospitalization and vigilant treatment.

Prophylactic internal iliac artery ligation at cesarean hysterectomy

One hundred and eight preplanned cesarean hysterectomies have been evaluated in an effort to determine that advisability of prophylactic bilateral hypogastric artery ligation when there is anticipated heavy bleeding associated with surgery. The data indicates that prophylactic bilateral internal iliac artery ligation is of questionable value in reducing operative bleeding, which can be controlled by more conventional means. However, when used therapeutically, it may be a lifesaving operation. Familiarity with the procedure is necessary for all those performing operative obstetrics and gynecology.

Spin-label studies of membrane-associated denatured hemoglobin in normal and sickle cells

A maleimide spin label (N-(1-oxyl-2,2,5,5-tetramethylpyrrolidinyl)-maleimide) was reacted with oxyhemoglobin-free cell stromata of normal and sickle cells. The EPR spectrum of spin-labeled red cell membranes showed that the spin labels are attached to at least two different binding sites. There was a major signal, A, which characterized a strongly immobilized environment and a minor signal, B, which characterized a weakly immobilized environment. Quantitative EPR measurements using equal amounts of Hb AA and Hb SS red blood cells demonstrated that Hb SS red cell membranes had an approximately four times higher EPR signal intensity than Hb AA red cell membranes ((7.98 +/- 1.14 . 10(5) and (2.2 +/- 1.2) . 10(5) spin labels/cell, respectively). Moreover, the ratio of signal intensities A and B are different in these cells. Comparative spectrophotometric studies of membrane-associated denatured hemoglobins of Hb AA and Hb SS red cell membranes suggested that the EPR signal A is derived from spin labels attached to membrane-associated denatured hemoglobin, while signal B is mainly from spin labels attached to membranes. The combination of EPR spectrum of Hb AA membranes pretreated with N-ethylmaleimide and that of spin-labeled precipitated hemoglobin further strengthened this conclusion.

Differential expression of Hox A5 in human colon cancer cell differentiation: a quantitative study using real-time RT-PCR

Fifteen different homeobox genes were identified from normal colon mucosa, untreated COLO 205 and herbimycin A treated COLO 205 cells in a degenerate primer RT-PCR screen. Several of the homeobox genes, including Cdx-1, Cdx-2, Pdx-1 and Hox A5, showed a trend toward differential expression in normal colon mucosa, and undifferentiated COLO 205 cells. Hox A5 was recently shown to suppress growth and induce p53-dependent apoptosis. To determine if Hox A5 was differentially expressed in differentiation of colon epithelial cells, we quantified Hox A5 expression by real-time quantitative RT-PCR. Expression of Hox A5 was 5.3- and 4.8-fold higher in normal colon mucosa compared to COLO 205 and HT-29 cells, respectively, suggesting that Hox A5 expression was higher in differentiated compared to undifferentiated colon epithelial cells. To avoid the complexity of tissue specimens and the influence of individual variation in Hox A5 expression, the effect of differentiation on Hox A5 expression was studied in COLO 205 cells treated with herbimycin A. The quantitative study showed that Hox A5 expression was increased when COLO 205 cells were induced to differentiate. The expression of Hox A5 was about 2-fold higher in the cells treated for 48 h compared to the untreated poorly-differentiated cells. The present study shows that Hox A5 may be involved in intestinal cell differentiation, in addition to its role in apoptosis.

Characterization of protein arginine methyltransferases in porcine brain

Protein arginine methylation is a posttranslational modification involved in various cellular functions including cell signaling, protein subcellular localization and transcriptional regulation. We analyze the protein arginine methyltransferases (PRMTs) that catalyze the formation of methylarginines in porcine brain. We fractionated the brain extracts and determined the PRMT activities as well as the distribution of different PRMT proteins in subcellular fractions of porcine brain. The majority of the type I methyltransferase activities that catalyze the formation of asymmetric dimethylarginines was in the cytosolic S3 fraction. High specific activity of the methyltransferase was detected in the S4 fraction (high-salt stripping of the ultracentrifugation precipitant P3 fraction), indicating that part of the PRMT was peripherally associated with membrane and ribosomal fractions. The amount and distribution of PRMT1 are consistent with the catalytic activity. The elution patterns from gel filtration and anion exchange chromatography also indicate that the type I activity in S3 and S4 are mostly from PRMT1. Our results suggest that part of the type I arginine methyltransferases in brains, mainly PRMT1, are sequestered in an inactive form as they associated with membranes or large subcellular complexes. Our biochemical analyses confirmed the complex distribution of different PRMTs and implicate their regulation and catalytic activities in brain.