Recombinant human growth hormone promotes hematopoietic reconstitution after syngeneic bone marrow transplantation in mice

Recombinant human growth hormone (rhGH) was administered to mice after syngeneic bone marrow transplantation (BMT) to determine its effect on hematopoietic reconstitution. BALB/c mice were given 10 microg intraperitoneal injections of rhGH every other day for a total of 10 injections following syngeneic BMT. Mice that received rhGH exhibited significant increases in total hematopoietic progenitor cell content (colony-forming unit-culture) in both bone marrow and spleen. Erythroid cell progenitor content (burst-forming unit-erythroid) was also significantly increased after rhGH treatment. Analysis of peripheral blood indicated that administration of rhGH resulted in significant increases in the rate of white blood cell and platelet recovery. Granulocyte marker 8C5+ cells were also increased in the bone marrow and spleens of treated mice. Red blood cell, hematocrit, and hemoglobin levels were increased at all time points after rhGH treatment. No significant pathologic effects or weight gain were observed in mice receiving repeated injections of 10 microg rhGH. Thus, rhGH administration after syngeneic BMT promoted multilineage hematopoietic reconstitution and may be of clinical use for accelerating hematopoiesis after autologous BMT.

The correlation of telomerase and IL-10 with leukemia transformation in a mouse model of chronic lymphocytic leukemia (CLL)

Telomerase activity is upregulated in activated and malignant lymphocytes. We studied the correlation of telomerase and IL-10 to leukemia transformation in the NZB mouse model of human chronic lymphocytic leukemia (CLL). Telomerase levels increased from early to late leukemic stages, likewise IL-10 gene expression levels increased with the leukemic progression. The inverse relationship of telomerase and IL-10 levels to the survival of NZB mice was also established. Our data suggested that telomerase and IL-10 were involved in transformation in the murine model of CLL and the detection of telomerase activities might be of value in the prediction of CLL progression.

In vitro evaluation of the efficacy of the capsular tension ring for managing zonular dialysis in cataract surgery

BACKGROUND AND OBJECTIVE

In vitro evaluation of the capsular tension ring for managing zonular dialysis in cataract surgery.

MATERIALS AND METHODS

Pig and cadaver eye models were used in this study. Lens material was removed with phacoemulsification, then the zonules were cut in one quadrant of the meridian to induce capsular bag decentration. Posterior chamber intraocular lenses (PC IOLs) were implanted into the bag with or without the tension rings. The IOL and the tension ring positions were viewed using the Miyaki technique. PC IOLs were also implanted into isolated capsular bags with or without tension rings, and bag configuration was examined.

RESULTS

The IOL decentration was observed when the IOLs were implanted into the eyes without zonular support in one quadrant of the meridian. No IOL decentration was observed when the tension ring and the IOL were implanted together. When only the IOLs were inserted into the isolated bags they became oval, whereas the circular bags were preserved when both the IOL and the tension ring were placed in-the-bag.

CONCLUSION

The authors' in vitro model demonstrated that the capsular tension ring maintained the circular contour of the capsular bag and IOL centration in the eyes with broken zonules. The results suggest that capsular tension rings may provide an alternative means to manage zonular dialysis during phacoemulsification and PC IOL implantation.

High prevalence of antibodies to human herpesvirus 8 in relatives of patients with classic Kaposi's sarcoma from Sardinia

A survey for antibodies to a recombinant small viral capsid antigen (sVCA) of human herpesvirus type 8 (HHV-8) was conducted in Sardinia, one of the world's highest incidence areas for classic Kaposi's sarcoma (KS). Prevalence of antibodies to HHV-8 sVCA was greatest in patients with KS (95%), followed by family members (39%) and a Sardinian control population age- and sex-matched to the relatives (11%). Within families, prevalence of antibodies was about equal among spouses, children, and siblings of KS patients, a finding that raises the possibilities of intrafamilial person-to-person or vertical transmission. Antibodies were detected 2-3 times more frequently in males than in females. The data show that prevalence of antibodies to HHV-8 sVCA correlates with the distribution of classic KS in a high- incidence area. Clustering of seroprevalence within some families suggests the presence of familial risk factors for active HHV-8 infection.

[The predominant expression of Th2 type cytokines in human tumor cells]

OBJECTIVE

To observe the expression of Th1 versus Th2 type cytokines in human tumor cells.

METHODS

The gene expression of Th1/Th2 cytokines in human tumor cells was detected by RT-PCR and RNA dot hybridization using IL-2 and IFN gamma as Th1 type cytokine genes, IL-4, IL-10 and IL-13 as Th2 type cytokine genes.

RESULTS

There were predominant expressions of Th2 type cytokines in 20 different human tumor cell lines including 11 solid tumor and 9 hematogenous tumor cells.

CONCLUSION

Predominant expression of Th2 type cytokines by tumor cells may be related to the evasion of tumor cells from immune surveillance.

Serologic association of human herpesvirus eight with posttransplant Kaposi's sarcoma in Saudi Arabia

BACKGROUND

This study investigates the association between human herpesvirus eight (HHV8) and Kaposi's sarcoma (KS), the most common cancer occurring in renal transplant recipients in Saudi Arabia.

METHODS

A cross-sectional study of seroreactivity to HHV8 antigens in posttransplant KS patients from a tertiary care hospital in Riyadh, Saudi Arabia, and in control subjects without KS was conducted. Seroreactivity rates were determined using immunoblotting assays to detect antibodies to two lytic cycle HHV8 antigens: p40, an antigen found in infected cells, and sVCA, an HHV8-encoded small viral capsid antigen expressed in Escherichia coli.

RESULTS

Antibodies to HHV8 p40 and sVCA were present in a significantly higher proportion of renal transplant patients with KS (13 of 14 patients) compared to renal transplant patients without KS (5 of 18; P<0.001) and compared to other control individuals (6 of 44; P<0.001). HHV8 seroreactivity was more common among patients with renal failure (28%) than among other control groups (7%).

CONCLUSIONS

The serologic results provide evidence of a strong association between HHV8 and posttransplant KS in Saudi Arabia.

Isolation and Fractional Characterization of Ball-Milled and Enzyme Lignins from Oil Palm Trunk

Ball-milled and enzyme lignins were isolated from the trunks of oil palms and subsequently studied. The lignins were fractionated into pure milled lignin (PML), pure enzyme lignin (PEL), lignin rich enzyme lignin (LREL), hemicellulose rich milled lignin (HRML), and solubilized lignin obtained during enzyme treatment (SLET) fractions by a two-step precipitation method. The chemical and structural composition of the five lignin preparations was determined by using UV, GPC, FT-IR, (13)C NMR spectroscopy and nitrobenzene oxidation. Pure milled lignin and pure enzyme lignin fractions were found to contain rather low amounts of neutral sugars, 2.2-3.1%. The lignin fractions contained a high proportion of noncondensed syringyl units with small amounts of noncondensed guaiacyl and p-hydroxyphenyl units. Trace amounts of p-coumaric and ferulic acids were also found to be associated with lignin in the oil palm trunk cell walls.

[SERS and electrochemistry studies on the inhibition of thiourea and phenyl-thiourea on iron]

An iron electrode was obtained by depositing a thin layer of iron on active silver electrode with overpotential deposition method. The E - I curve and SERS spectra of thiourea (TU) and phenyl-thiourea (PTU) adsorbed on the iron electrode surface were studied by means of electrochemistry and SERS spectroscopy. The results showed that both TU and PTU can be adsorbed on the iron electrode surface and the inhibition of PTU is better than TU in 0.1mol/L KCl solution. The adsorption mode of TU and PTU is similar in the interaction of S atom and iron surface. The cause of better inhibition effect of PTU lies in that the PTU can be more easily adsorbed on iron electrode because of more negative charge in its S atom and benzene ring in PTU is arranged away from the iron surface to form a rather compact adsorption layer due to steric hindrance.

[Changes of PDGF-alpha and beta receptor gene expression in hypoxic rat pulmonary vessels]

OBJECTIVE

To reveal the role of platelet-derived growth factor-alpha and beta receptor in hypoxic pulmonary vascular remodeling. We investigated the changes of PDGF-alpha and beta receptor gene expression under hypoxic condition.

METHODS

Hypoxic pulmonary hypertension rats model was reproduced by normobaric hypoxia. Changes of pulmonary PDGF-alpha and beta mRNA were examined by in situ hybridization.

RESULTS

The PDGF-alpha receptor mRNA of the hypoxia group (3 days) declined to 86% compared with that of the control group, and shooting up to 217% of control at day 7, then sustained at 224% until day 14. (all P < 0.001). PDGF-beta receptor mRNA markedly increased at day 3 after hypoxia and maintained this increasing tendency consistently. Its top was 164% at day 14 (P < 0.001). The growth inhibitor, heparin had alleviated the increases of both rat pulmonary arterial pressure and PDGF receptor gene expression.

CONCLUSION

Hypoxia led to the increase of PDGF-alpha and beta receptor gene expression in pulmonary vascular endothelial and smooth muscle cells, and might be involved in hypoxic pulmonary vascular remodeling.

The locus of Epstein-Barr virus terminal repeat processing is bound with enhanced affinity by Sp1 and Sp3

EBV DNA contains G-rich, repeat regions that are involved in rearrangement and recombination events including terminal repeat (TR) processing and the EBNA-2 deletion in the EBV strain P3HR-1. Cellular proteins, called terminal or tandem repeat binding proteins (TRBPs), recognize sequences at the junctions of these recombination events. In this study, using antibody supershift assays and expression of recombinant proteins, we show that Sp1 and Sp3 are the sequence-specific components of TRBP and that Ku is the nonspecific binding component. Sp1 binds other recombinogenic regions of EBV DNA, but Sp3 does not bind to the large internal repeat. The sequence GGGGTGGGG, a low affinity site for Sp1 and Sp3, is the minimal binding site within terminal repeat binding site 1 (TRBS1). However, 3' flanking sequences in the sequence GGGGTGGGGCATGGGG augment binding of Sp1 and Sp3 so that their affinity of binding is increased approximately twofold relative to a classical high-affinity Sp1 site. EBV lytic cycle induction does not alter the abundance or binding activity of any of the three identified components of TRBP. Sp1 and Sp3 may act in trans to promote EBV terminal repeat processing and possibly other viral and cellular recombination events.

Sp1 binds to the precise locus of end processing within the terminal repeats of Epstein-Barr virus DNA

Interconversion between the linear genome of Epstein-Barr virus (EBV) present in virions and intracellular circular EBV DNA is a novel DNA recombination process. A previously characterized DNA binding activity called terminal repeat or tandem repeat binding protein (TRBP) was found to recognize several G-rich recombinogenic sequences in the EBV genome and in cellular DNA. TRBP was also found to be an autoantigen recognized by sera from certain patients with undifferentiated connective-tissue disorders. Here the transcription factor Sp1 has been identified as a component of TRBP and has been shown to be an autoantigen. Sp1 bound to recombination junctions of EBV DNA, such as those in the terminal repeats and in the large internal repeats, as well as to recombinogenic regions of cellular DNA, such as variable-number tandem repeats and switch regions of the immunoglobulin genes. We defined the ends of the linear EBV genome present in virions and showed that Sp1 binds to the sequence (GGGGTGGGGCATGGG) within EBV terminal repeats at the precise locus of interconversion of linear and circular viral DNA. Sp1 may be involved in DNA recombination.

Temporal trends and factors associated with survival after Pneumocystis carinii pneumonia in California, 1983-1992

The authors investigated quarterly trends in survival after the diagnosis of Pneumocystis carinii pneumonia for 19,607 patients in California in the decade from January 1, 1983, through December 31, 1992. Subjects included all cases for whom P. carinii pneumonia was the initial (and only) acquired immunodeficiency syndrome (AIDS)-defining diagnosis as reported to the California human immunodeficiency virus/AIDS surveillance registry. There was a period of rapidly improving survival from approximately June 1986 until April 1988, coincident with the widespread introduction of antiretroviral therapy (zidovudine) and the institution of P. carinii pneumonia prophylaxis (with cotrimoxazole and pentamidine). There was no evidence, however, of meaningful improvements in survival for these patients after that period. The association of several covariates (risk transmission group, gender, race/ethnicity, certainty of P. carinii pneumonia diagnosis, age, region of residence, availability of CD4 count, and level of CD4 count) were also studied both by proportional hazards regression and by recursive partitioning (i.e., tree-based) survival analysis. The availability of a CD4 count (regardless of its level) was the single factor most strongly associated with survival (median survival 36 months among those with and 14 months among those without reported CD4 counts, p < 0.05). Data from this large, population-based surveillance registry of AIDS in California suggest that, despite earlier improvements in survival after the diagnosis of P. carinii pneumonia, the long-term survival of these patients remains poor (39% alive 2 years after diagnosis) and that no improvement in survival has occurred since 1988.

The transcriptional activator Sp1, a novel autoantigen

OBJECTIVE

To identify one nuclear autoantigenic protein within a complex of DNA binding proteins that bind to GC-rich sequences in Epstein-Barr virus and cellular DNA, and to describe the clinical characteristics of patients whose sera contained autoantibodies to this novel autoantigen.

METHODS

Antibodies to autoantigen Sp1 were initially measured by an electrophoretic mobility shift assay to detect DNA binding proteins. Nuclear extracts and purified Sp1 protein were used in these assays. Recognition of the autoantigen by autoimmune sera was confirmed by immunoprecipitation and immunoblotting.

RESULTS

The autoantigen was identified as Sp1. Anti-Sp1 was detected in sera from 8 (3%) of 230 patients. These sera contained antinuclear antibodies, but lacked antibodies to double-stranded DNA or to several extractable nuclear antigens. The patients whose sera contained antibodies to Sp1 were white women with fatigue, arthritis, Raynaud's phenomenon, malar rash, and photosensitivity.

CONCLUSION

Sp1 is the first described example of an RNA polymerase II transcription activator as an autoantigen. The presence of Sp1 autoantibodies is associated with undifferentiated connective tissue disease.

[Clinical study of the relationship between the lateral recesses and the nerve roots]

To explicate the relationship and the clinical signification between the normal or narrow lateral recesses and the nerve roots, we measured the diameter of the entrans zone of the lateral recess, the interval between the upper articular processes and the interval between the nerve root and ab line on 50 normal cases, 43 narrow cases and 32 stenosis cases with VIDS image analysis system. The results showed that the nerve root was in the center side of the ab line in the normal station, with the degrees of the degeneration and cohesion ncreasing, the nerve root was in the lateral recess side of the ab line, and was compressed by the lateral recess. The authors considered that the real clinical signification of the entrance zone of the lateral recess was danger to the nerve root, but the deciding factors were the degrees of the degeneration and cohesion of the upper articular processes. The pathological conditions that resulted in the stenosis of the lateral recess and dangered the nerve root such as disc, flavum ligament and posterior port of the fibra ring were discussed in the article.

Detection of hepatitis C by RT-PCR in formalin-fixed paraffin-embedded tissue from liver transplant patients

The histopathologic alterations of hepatitis C virus (HCV) infection of the liver overlap with those of other diseases, making interpretation of liver biopsy specimens in some cases insufficient to render a diagnosis. Although HCV infection can be confirmed by detection of circulating anti-HCV antibodies, immunocompromised liver transplant recipients are often unable to mount an immunologic response to the virus, resulting in false-negative serologic testing. We describe the comparison of reverse transcription-polymerase chain reaction (RT-PCR) with histopathology, serology, and immunohistochemistry for the diagnosis of HCV. Sixty-three formalin-fixed, paraffin-embedded tissue samples (40 needle biopsy specimens and 23 native liver resection specimens) from 35 transplant patients were analyzed by use of a novel method of RNA extraction followed by nested PCR for HCV as well as albumin mRNA as an internal control. HCV was detected by RT-PCR in 50 of 51 (98%) paraffin sections of liver from transplant patients with circulating anti-HCV antibodies, 15 of which lacked characteristic histologic features of HCV infection. Overall, there were no false-negative results in 36 needle biopsy specimens from patients with hepatitis C infection, but three negative results were seen in end-stage cirrhotic native livers resected from HCV-infected patients. No false-positive test results were seen among 21 negative controls (10 liver samples from immunocompetent patients with abnormalities unrelated to hepatitis C and 11 liver biopsies from immunocompetent patients without histologic evidence of liver disease). In comparison, immunohistochemistry using antibody TORDJI-22 was positive for HCV in only 15 of 32 (47%) needle biopsies positive by RT-PCR. Our results indicate that RT-PCR is a more sensitive and specific method of detecting hepatitis C in routinely processed paraffin sections of formalin-fixed liver biopsy specimens than histopathologic examination or immunohistochemistry.

Management of zonular dialysis in phacoemulsification and IOL implantation using the capsular tension ring

BACKGROUND AND OBJECTIVES

Cataract surgery with zonular dialysis remains a challenge for surgeons performing phacoemulsification and posterior chamber intraocular lens implantation. In this article, the authors report the results of cataract surgery with zonular dialysis that was managed with the capsular tension ring.

PATIENTS AND METHODS

Of the 14 cataract surgery cases with loose or broken zonules managed with capsular tension rings that were retrospectively reviewed, 5 selected cases are presented in this article.

RESULTS

The authors found that the capsular tension ring helps to avoid capsular collapse and vitreous presentation during surgery and maintains the circular contour of the capsular bag, allowing the intraocular lens to easily be placed into the bag. There was no observable decentration of the intraocular lens after surgery.

CONCLUSION

The capsular tension ring may provide an alternative means to manage zonular dialysis during phacoemulsification and posterior chamber intraocular lens implantation.

Identification, expression, and immunogenicity of Kaposi's sarcoma-associated herpesvirus-encoded small viral capsid antigen

We describe a recombinant antigen for use in serologic tests for antibodies to Kaposi's sarcoma (KS)-associated herpesvirus (KSHV). The cDNA for a small viral capsid antigen (sVCA) was identified by immunoscreening of a library prepared from the BC-1 body cavity lymphoma cell line induced into KSHV lytic gene expression by sodium butyrate. The cDNA specified a 170-amino-acid peptide with homology to small viral capsid proteins encoded by the BFRF3 gene of Epstein-Barr virus and the ORF65 gene of herpesvirus saimiri. KSHV sVCA was expressed from a 0.85-kb mRNA present late in lytic KSHV replication in BC-1 cells. This transcript was sensitive to phosphonoacetic acid and phosphonoformic acid, inhibitors of herpesvirus DNA replication. KSHV sVCA expressed in mammalian cells or Escherichia coli or translated in vitro was recognized as an antigen by antisera from KS patients. Rabbit antisera raised to KSHV sVCA expressed in E. coli detected a 22-kDa protein in KSHV-infected human B cells. Overexpressed KSHV sVCA purified from E. coli and used as an antigen in immunoblot screening assay did not cross-react with EBV BFRF3. Antibodies to sVCA were present in 89% of 47 human immunodeficiency virus (HIV)-positive patients with KS, in 20% of 54 HIV-positive patients without KS, but in none of 122 other patients including children born to HIV-seropositive mothers and patients with hemophilia, autoimmune disease, or nasopharyngeal carcinoma. Low-titer antibody was detected in three sera from 28 healthy subjects. Antibodies to recombinant sVCA correlate with KS in high-risk populations. Recombinant sVCA can be used to examine the seroepidemiology of infection with KSHV in the general population.

Effects of Topical Ketorolac and Diclofenac on Normal Corneal Sensation

BACKGROUND

A randomized, double-masked study was conducted to investigate the effects of 0.5% ketorolac tromethamine (Acular) and 0.1% diclofenac sodium (Voltaren) on normal human corneal sensation.

METHODS

Thirty normal volunteers were divided into two groups, (1) two-drop group, and (2) multiple-drop group. In the two-drop group, 15 volunteers randomly received two drops of 0.5% ketorolac tromethamine on one eye and two drops of 0.1% diclofenac sodium on the fellow eye. A masked investigator measured corneal sensation with the Cochet-Bonnet esthesiometer before applying the drops, and at 15, 30, and 60 minutes after using the eye drops. In the multiple-drop group, another 15 volunteers were randomly administered one drop of 0.5% ketorolac tromethamine or 0.1% diclofenac sodium in each eye, and the procedure was repeated every 5 minutes for 20 minutes. Corneal sensation was measured before, and 0, 15, 30 and 60 minutes after applying the drops.

RESULTS

In the two-drop group, neither of the eye drops had any effect on corneal sensation when only two drops were applied. In the multiple-drop group, corneal sensation was significantly reduced after multiple drops (p < 0.05) and was subsequently effective for at least 1 hour.

CONCLUSION

Both 0.5% ketorolac and 0.1% diclofenac can significantly decrease corneal sensation in normal eyes when multiple drops are used.

[Study on relationship between personality traits and social life abilities in children]

Author surveyed 330 pupils and their parents by using Eysenck Pensonality Questionnaire (E. P. Q) and Infants-Junior Middle School Students' Social-Life Abilities Scale, to explore the relationship between personality and Social-life abilities in children. Result show there was no relationship between social-Life abilities and degrees of psychoticism, neuroticism and lie in children. It was closely related between social-life abilities and personality of children. The children with low social-life abilities are mostly introverted. The children with high social-life abilities, especially in communication, are mostly extroverted. Children over 10 year-old with high locomotion are mostly extroverted (P < 0.05). As results of the study, parents and pediatric nurses should assist the personality of children to be developed toward extroversion tendencies.

Excimer laser photorefractive keratectomy for residual myopia after radial keratotomy

OBJECTIVE

To evaluate the surgical outcome of excimer laser photorefractive keratectomy (PRK) for undercorrected myopia after radial keratotomy (RK).

DESIGN

Case series.

SETTING

Gimbel Eye Centre, Calgary.

PATIENTS

Thirty-one patients (37 eyes) who underwent excimer laser PRK for residual myopia after RK and were followed for at least 12 months.

OUTCOME MEASURES

Spherical equivalent refraction, uncorrected and best corrected Snellen visual acuity, attempted and achieved correction, and corneal haze.

RESULTS

The mean refraction before PRK was -3.11 (standard deviation [SD] 1.48) dioptres and 12 months after PRK, -1.18 D (SD 1.48 D) (p < 0.0001). Twelve months after PRK 24 eyes (64.9%) had an uncorrected visual acuity of 20/40 or better. Five eyes lost one line of best corrected acuity, and one eye lost more than two lines. At 12 months 28 eyes (75.7%) had no corneal haze or trace haze, 8 (21.6%) had mild haze, and 1 (2.7%) had marked haze.

CONCLUSIONS

Our results indicate that excimer laser PRK has the potential to manage undercorrection of myopia after RK. The issues of refractive predictability, loss of best corrected visual acuity and corneal haze require further study.

The effect of timing of ondansetron administration in outpatients undergoing otolaryngologic surgery

A randomized, double-blind, placebo-controlled study was designed to compare the relative efficacy of prophylactic ondansetron, 4 mg intravenously (IV), when administered before induction of anesthesia or at the end of surgery to an outpatient population at high risk of developing postoperative nausea and vomiting (PONV). Patients undergoing otolaryngologic surgery were randomly assigned to one of three different treatment groups: Group 1 (placebo) received saline 5 mL prior to induction of anesthesia and again at the end of surgery; Group II received ondansetron 4 mg in 5 mL prior to induction of anesthesia and saline 5 mL at the end of surgery; and Group III received saline 5 mL prior to induction of anesthesia and ondansetron 4 mg at the end of surgery. All patients received the same general anesthetic technique. A standardized regimen of rescue antiemetics was administered in the recovery room to patients with > or = 2 emetic episodes or at the patients request for persistent nausea. Episodes of nausea and vomiting, as well as the need for rescue antiemetics, were recorded for 24 h after the operation. The incidences of nausea and emesis in the recovery room after prophylactic ondansetron, 4 mg IV, administered either before induction (68% and 20%, respectively) or at the end of surgery (60% and 4%, respectively) were not significantly decreased compared to the placebo control group (80% and 12%, respectively). However, when ondansetron was administered at the end of the operation, it significantly reduced the need for rescue antiemetics in the recovery room (36% vs 64% in the control group). The postanesthesia care unit and hospital discharge times were similar in all three study groups. One patients in Group II and one patient in Group III were hospitalized because of intractable symptoms related to PONV. After discharge from the ambulatory surgery unit, the incidence of nausea, vomiting, and the need for rescue antiemetic drugs were similar in all three treatment groups. In conclusion, ondansetron (4 mg IV) was more effective in reducing the need for rescue antiemetics in the recovery room when administered at the end versus prior to the start of otolaryngologic surgery. Therefore, when ondansetron is used for antiemetic prophylaxis in outpatients undergoing otolaryngologic procedures, it should be administered at the end of the operation rather than prior to induction of anesthesia.

Selective switch between latency and lytic replication of Kaposi's sarcoma herpesvirus and Epstein-Barr virus in dually infected body cavity lymphoma cells

The BC-1 cell line, derived from a body cavity-based, B-cell lymphoma, is dually infected with Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV). In these studies, the relationships between these two gammaherpesviruses and BC-1 cells were characterized and compared. Single-cell cloning experiments suggested that all BC-1 cells contain both genomes. In more than 98% of cells, both viruses were latent. The two viruses could be differentially induced into their lytic cycles by chemicals. EBV was activated into DNA replication and late-gene expression by the phorbol ester tetradecanoyl phorbol acetate (TPA). KSHV was induced into DNA replication and late-gene expression by n-butyrate. Amplification of both EBV and KSHV DNAs was inhibited by phosphonoacetic acid. Induction of the KSHV lytic cycle by n-butyrate was accompanied by the disappearance of host-cell beta-actin mRNA. Induction of EBV by TPA was not accompanied by such an effect on host-cell gene expression. Induction of the KSHV lytic cycle by n-butyrate was associated with the expression of several novel polypeptides. Recognition of one of these, p40, served as the basis of development of an assay for antibodies to KSHV in the sera of infected patients. BC-1 cells released infectious EBV; however, there was no evidence for the release of encapsidated KSHV genomes by BC-1 cells, even though n-butyrate-treated cells contained numerous intranuclear nucleocapsids. The differential inducibility of these two herpesviruses in the same cell line points to the importance of viral factors in the switch from latency to lytic cycle.

gp120, a human immunodeficiency virus-1 coat protein, augments excitotoxic hippocampal injury in perinatal rats

Recent data suggest that gp120, a human immunodeficiency virus-1 (HIV-1) coat glycoprotein that is secreted by HIV-infected cells, is neurotoxic, and that this toxicity is mediated, at least in part, by activation of N-methyl-D-aspartate-type excitatory amino acid receptors. To test this hypothesis in vivo, we examined the neurotoxicity of gp120 injected intrahippocampally, alone or co-injected with the selective excitatory amino acid agonist N-methyl-D-aspartate, in seven-day-old rats. Severity of injury in the lesioned hippocampus was assessed five days later, using three outcome measures: histopathology, hippocampal atrophy (derived from regional cross-sectional area measurements) and loss of [3H]glutamate receptor binding (based on in vitro autoradiography assays). To confirm that any observed effects were attributable to gp120 bioactivity, each group of experiments included controls that received equal amounts of heat-treated gp120. Gp120 (200 ng) elicited minimal focal pyramidal cell loss immediately adjacent to the injection track; there was no hippocampal atrophy or loss of [3H]glutamate binding. Co-injection of 50 ng gp120 with N-methyl-D-aspartate (5 nmol, threshold excitotoxic dose) increased the severity of hippocampal injury; hippocampal atrophy was greater in animals that received injections of 5 nmol N-methyl-D-aspartate in combination with 50 ng gp120 than in those that received either N-methyl-D-aspartate alone (5 nmol) or 5 nmol N-methyl-D-aspartate+50 ng heat-treated gp120 (mean+/-S.E.M. percentage reduction in injected hippocampal volume vs contralateral: N-methyl-D-aspartate, -19+/-3; N-methyl-D-aspartate+gp120, -26.8+/-2.1; N-methyl-D-aspartate+heat-treated gp120, -14.0+/-2.2; P<0.001, ANOVA). Treatment with the competitive N-methyl-D-aspartate antagonist 3-((RS)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (20mg/kg) markedly reduced the severity of injury elicited by the combination of gp120 with N-methyl-D-aspartate. These data support the hypothesis that locally secreted gp120 could exert neurotoxic effects, mediated by N-methyl-D-aspartate receptor activation, in vivo in the immature brain.

Effect of commercial dilating agents on laser flare-cell measurements

OBJECTIVE

To compare the effect of tropicamide alone and tropicamide-phenylephrine on anterior chamber flare and cell measurements obtained with a laser flare-cell meter.

DESIGN

Prospective study.

SETTING

Gimbel Eye Centre, Calgary.

SUBJECTS

Twenty white subjects (10 with blue irides and 10 with brown irides) aged 24 to 45 (mean 30.2) years without any known systemic or ocular disease.

INTERVENTIONS

Laser flare-cell measurements were obtained 30 minutes after pupillary dilation with 1% tropicamide in one eye and a combination drop of 0.8% tropicamide and 5% phenylephrine in the other eye. The average of five readings was taken for each eye.

OUTCOME MEASURES

Flare and cell measurements.

RESULTS

There was no statistically significant difference in flare photon count or cell count between the eyes dilated with tropicamide and those dilated with tropicamide-phenylephrine. In addition, iris colour was not found to have a significant effect on flare and cell measurements.

CONCLUSIONS

Our results suggest that pupillary dilation for laser flare-cell measurements can be done with either mydriatic agent in healthy white subjects of any eye colour without significant effects on the measurements. Further study is needed to determine whether the same is true in older subjects.

Differential production of interleukin-6 and its close relation to liver metastasis in clones from murine P815 mastocytoma

Interleukin-6 (IL-6)-producing abilities of plastic-adherent and plastic-non-adherent P815 clones were investigated in connection with the liver metastasis. Most adherent clones produced IL-6 at high level (over 10 ng/10(5) cells per 48 h), and they coincided with highly liver-metastatic clones. The remaining adherent and all the non-adherent clones tested produced IL-6 at low level (under 1.5 ng/10(5) cells), and they coincided with the low or non-liver-metastatic clones. The IL-6 production was greatly enhanced by IL-1 alpha, but not by IL-6, tumor necrosis factor-alpha or interferon-gamma.

Two 21-kilodalton components of the Epstein-Barr virus capsid antigen complex and their relationship to ZEBRA-associated protein p21 (ZAP21)

The viral capsid antigen complex of Epstein-Barr virus (EBV), an important serodiagnostic marker of infection with the virus, consists of at least four components, with molecular masses of 150, 110, 40, and 21 kDa. Here we show that the 21-kDa component of the viral capsid antigen consists of products of two EBV genes, BFRF3 and BLRF2. Both products were expressed from late transcripts, were recognized by human antisera, and were present in virions. The BFRF3 product, but not that of BLRF2, fulfilled the definition of ZEBRA-associated protein p21 (ZAP21). In cells in which EBV was lytically replicating, BFRF3 protein was coimmunoprecipitated together with ZEBRA by a rabbit antiserum directed against amino acids 197 to 245 of BZLF1. In EBV-negative cells cotransfected with BZLF1 and BFRF3 expression vectors, BFRF3 was also coimmunoprecipitated with this antiserum. Although this antiserum could not detect BFRF3 on an immunoblot, it was able to immunoprecipitate BFRF3 in the absence of ZEBRA expression. The rabbit antiserum to amino acids 197 to 245 of BZLF1 was found to detect the same epitope at the carboxy end of BFRF3 as was recognized by rabbit antiserum to BFRF3 itself. Thus, coimmunoprecipitation of BFRF3 p21 with ZEBRA appeared to be due to cross-reactivity of the immunoprecipitating antiserum rather than to direct association of ZEBRA and BFRF3 p21.

Polyadenylylated nuclear RNA encoded by Kaposi sarcoma-associated herpesvirus

A newly recognized gamma herpesvirus known as Kaposi sarcoma-associated herpesvirus (KSHV) or human herpesvirus 8 (HHV8) is present in Kaposi sarcomas and body-cavity-based lymphomas. Here we identify a novel abundant 1.2-kb RNA, polyadenylated nuclear RNA (PAN RNA), encoded by the virus. The majority of cDNAs produced from poly(A)-selected RNA isolated from a human body cavity lymphoma cell line 48 hr after butyrate induction of KSHV lytic replication represented PAN RNA. Within PAN RNA were two 9 and 16 nt stretches with 89% and 94% identity to U1 RNA. A third stretch of 14 nt was 93% complementary to U1. The 5' upstream region of PAN RNA contained both proximal and distal sequence elements characteristic of regulatory regions of U snRNAs, whereas the 3' end was polyadenylylated. PAN RNA was transcribed by RNA polymerase II, lacked a trimethylguanosine cap, and did not associate with polyribosomes. PAN RNA formed a speckled pattern in the nucleus typical of U snRNAs and colocalized with Sm protein. Therefore, PAN represents a new type of RNA, possessing features of both U snRNA and mRNA.

[Effect of 764-3 and ligustrazine on collagen content of extrapulmonary arteries during chronic hypoxia]

OBJECTIVE

Effect of two antifibrotic Chinese drugs, 764-3 and ligustrazine, on collagen content in chronic hypoxic pulmonary hypertensive extrapulmonary arterial wall were examined.

METHODS

Since collagen contains more than 10% hydroxyproline by weight and in other proteins there are almost no hydroxyproline, collagen content was expressed as micrograms of hydroxyproline. Hydroxyproline was determined by calorimetric method after oxidized by chloramine T.

RESULTS

Both 764-3 and ligustrazine significantly inhibited the increase of pulmonary arterial pressure and elevation of hydroxyproline content in extrapulmonary arterial wall during chronic hypoxia.

CONCLUSIONS

764-3 and ligustrazine may be two hopeful therapeutic drugs for chronic hypoxic pulmonary hypertension.

In vivo CTL immunity can be elicited by in vitro reconstituted MHC/peptide complex

The use of peptides as a vaccine is a potentially powerful immunization strategy. We explored the possibility of inducing an efficient cytotoxic T lymphocyte (CTL) mediated immune response in mice, using in vitro reconstituted major histocompatibility complex (MHC) class I/peptide complexes as the immunogen. Recombinant derived H-2Kb and beta 2-microglobulin (beta 2m) were properly folded into an MHC class I complex using the vesicular stomatitis virus (VSV)-8mer from the natural nucleocapsid proteinN52-59 (RGYVYQGL), an immunodominant Kb epitope in C57BL/6 (B6) mice. After immunizing mice with the H-2Kb class I/VSV peptide complex and a subsequent in vitro stimulation with the VSV peptide alone, a specific CTL response was demonstrated. The method was also applicable to other peptides, for example, the Sendai virus (SV) peptideN324-332 (FAPGNYPAL). The CTL response was mediated by CD3+/CD8+ T cells and was shown to be allele specific, as only peptide loaded target cells expressing the H-2Kb allele could be recognized. It is of interest that extremely small amounts of injected MHC class I/peptide complex (i.e. 500 pg) could generate a measurable CTL response. The MHC class I/peptide complex had to be intact and properly folded to elicit an immune response, suggesting that the complex protected the peptide for internalization by antigen presenting cells (APCs) or for delivering to the proper site for peptide exchange on the cell surface of APCs. The described immunizing method can be routinely used to prime a CTL response by employing in vitro folded MHC class I/peptide complexes, without the use of adjuvants. It appears to be efficient, sensitive and specific. By using the recombinant protein system, unlimited amounts of MHC class I/peptide complex can be produced for immunization. Moreover, this protocol permits different in vitro combinations of allelic MHC class I molecules and peptide variants.

[Three-dimensional recons-truction of lumbar-sacral canal and its contents: experimental study]

In order to suit the needs of studies in spinal column surgery on three-dimensional spatial structure and morphology of lumbar-sacral canal and the nervous tissue within it, an experimental model was applied by the authors using lumbosacral specimens from two fresh young adult cadavers. Successive 2mm thick CTM screening was carried out from L3 to S2 vertebral bodies with an interval of 1mm. The serial two-dimensional CT photographical pictures so obtained were inputted into a computer and the three-dimensional images were reconstructed through a VIDAS image analysis system. The experimental results indicated that the three-dimensional images of reconstructed vertebral canal and the nervous tissue within it were lifelike. These images could not only reveal their three-dimensional structure and morphology, but also be cut and composed together at any direction and section by turning and transpositioning along X, Y and Z axes. The authors hold that the visual effect expressed by three-dimensional images reconstructed from two-dimensional pictures can play important role in stereomorphologic, biomechanical, and other studies in fields of anatomy, image analysis, and clinical medicine.

Antibodies to butyrate-inducible antigens of Kaposi's sarcoma-associated herpesvirus in patients with HIV-1 infection

BACKGROUND

The recent identification in patients with Kaposi's sarcoma of DNA sequences with homology to gammaherpesviruses has led to the hypothesis that a newly identified virus, Kaposi's sarcoma-associated herpeslike virus (KSHV), has a role in the pathogenesis of Kaposi's sarcoma. We developed serologic markers for KSHV infection.

METHODS

KSHV antigens were prepared from a cell line (BC-1) that contains the genomes of both KSHV and the Epstein-Barr virus (EBV). We used immunoblot and immunofluorescence assays to examine serum samples from 102 patients with human immunodeficiency virus type 1 (HIV-1) infection for antibodies to KSHV-associated proteins and to distinguish these antibodies from antibodies to EBV antigens. A positive serologic response was defined by the recognition of an antigenic polypeptide, p40, in n-butyrate-treated BC-1 cells and by the absence of p40 recognition in untreated BC-1 cells or EBV-infected, KSHV-negative cells. The detection by the immunofluorescence assay of 10 to 20 times more antigen-positive cells in n-butyrate-treated BC-1 cells than in untreated cells was considered a positive response.

RESULTS

Antibodies to the p40 antigen expressed by chemically treated BC-1 cells were identified in 32 of 48 HIV-1-infected patients with Kaposi's sarcoma (67 percent), as compared with only 7 of 54 HIV-1-infected patients without Kaposi's sarcoma (13 percent). These results were confirmed by an immunofluorescence assay. The positive predictive value of the serologic tests for Kaposi's sarcoma was 82 percent, and the negative predictive value 75 percent.

CONCLUSIONS

The presence of antibodies to a KSHV antigenic peptide correlates with the presence of Kaposi's sarcoma in a high-risk population and provides further evidence of an etiologic role for KSHV.

Effect of pharmacological dilation and constriction of pupil on corneal topography

A prospective study was undertaken to investigate the effect of pharmacological pupillary dilation and constriction on corneal topography. Corneal topography was performed using the EyeSys system on 28 normal subjects before and after pupil dilation, constriction, and then with the pupil intact (no medication). Our results show that both flattening and steepening of the corneal curvature were found in all three examination periods. The numbers of corneas with flattening and steepening in each examination period were compared and found not to be statistically different. Mean change of corneal flattening was compared with mean change of corneal steepening in each examination period and again no significant difference was found. These results indicate that the slight changes in corneal power and radius following pharmacological pupillary dilation or constriction may be due to either the inability to repeat by the subjects, or error by observers or instrument.

The relationship between adherence and liver metastatic ability in murine mastocytoma cell line

P815 murine mastocytoma cells were separated to plastic-adherent and -nonadherent cell populations by repetitive in vitro selections. Their abilities of experimental and spontaneous metastases were investigated in the syngeneic DBA/2 mice. While the plastic-adherent populations were found to be liver-metastatic, the plastic-nonadherent populations were liver-nonmetastatic. The inability of plastic-nonadherent P815 cells to metastasize to the liver did not mean that these cells were not tumorigeneic because they could metastasize to tissues and/or organs other than the liver. Hence it could be looked as inability for liver specific metastasis resulted from, or related to, the loss of plastic adhesiveness. By limiting dilution of plastic-adherent and -nonadherent P815 cells, two series of well comparable P815 clones were established: (1) plastic-adherent, liver-metastatic clone and (2) plastic-nonadherent, liver-nonmetastatic one. Since these two series of P815 clone are originated from a common parent line, they might be valuable in the study of the molecular mechanisms of liver specific metastasis and of the relations between liver metastasis and cell adhesiveness.

Anterior chamber fluid cultures following phacoemulsification and posterior chamber lens implantation

BACKGROUND AND OBJECTIVE

A randomized, prospective study was undertaken to evaluate the incidence of positive cultures in the anterior chamber following cataract surgery when using intracameral gentamicin compared with no antibiotic.

PATIENTS AND METHODS

A total of 97 patients were enrolled-- 48 receiving gentamicin in the irrigating solution and 49 receiving no intracameral antibiotics (control group). Each cataract extraction was accomplished by phacoemulsification followed by intraocular lens implantation. At the end of surgery, o.1 ml of anterior chamber fluid from each case was collected and cultured.

RESULTS

All cultures were negative in the group receiving gentamicin. However, one positive culture occurred in the control group. There was no significant difference in the positive culture rate between the two groups (P = .52).

CONCLUSION

This study suggests that cataract extraction with phacoemulsification and intraocular lens implantation has greatly reduced the incidence of bacterial contamination of anterior chamber fluid, with or without the use of intracameral antibiotic.

Hypoxic-ischemic brain injury induces an acute microglial reaction in perinatal rats

Activated microglia may contribute to the progression of neuronal injury after a wide range of CNS insults. In this study, we used two complementary methods to evaluate acute changes in the morphology and regional distribution of microglia induced by a focal hypoxic-ischemic insult in 7-d-old (P7) rats. To elicit injury, P7 rats underwent right carotid ligation followed by 3 h of 8% O2 exposure; rats were killed 10 min to 5 d later (n > or = 3/group). A histochemical assay using Griffonia simplicifolia B4-isolectin enabled detection of both resting and activated microglia in tissue sections; vascular cells were also reactive. Activated microglia were also identified immunocytochemically using a macrophage-specific MAb, ED-1. In normal P7-12 brain, lectin, and ED-1 immunoreactive-activated microglia were concentrated in white matter; lectin-positive resting, ramified microglia were also detected throughout the gray and white matter. Subtle morphologic evidence of microglial activation was noted 10 min posthypoxia-ischemia in the lesioned right cerebral hemisphere; activated microglia began to accumulate within the next 4 h. Accumulation of lectin-positive activated microglia peaked at 2-4 d posthypoxia-ischemia. ED-1 immunoreactive-microglia were first noted 4 h after hypoxic-ischemic injury in the lesioned right hemisphere, and there was a corresponding increase in accumulation over the first 48 h posthypoxia-ischemia. In the left hemisphere, contralateral to the ligation, no increase in activated microglia were detected with either method. In brain sections where no neuronal injury was evident, activated microglia did not accumulate. These data demonstrate that perinatal hypoxic-ischemic brain injury induced rapid accumulation of activated microglia in hypoxic-ischemic forebrain.

Evidence that the antigen receptors of cytotoxic T lymphocytes interact with a common recognition pattern on the H-2Kb molecule

Recognition of class I MHC antigens involves interaction between TCRs of cytotoxic T lymphocytes (CTL) and the two alpha helices of MHC molecules. Using a combined panel of H-2Kb mutants selected by either a CTL clone or MAbs, we have shown evidence that the TCRs of 59 Kb-specific CTL clones shared a common binding pattern on the H-2Kb molecule. Mutations of amino acid residues at the C-terminal regions, but not the N-terminal regions, of the alpha helices abrogated the recognition by the majority of the clones. The data suggests that TCRs predominantly recognize the class I MHC molecule with an orientation that is parallel to the beta-pleated strands and diagonal to the alpha helices.

Effects of wound architecture and suture technique on postoperative astigmatism

BACKGROUND AND OBJECTIVE

A prospective randomized investigation was performed to evaluate the effects of wound architecture and suture techniques on postoperative astigmatism after phacoemulsification and intraocular lens implantation.

PATIENTS AND METHODS

Two hundred eyes with preexisting with-the-rule astigmatism were randomized into four groups: (1) sutureless scleral tunnel frown incision, (2) scleral tunnel frown incision with a horizontal suture, (3) scleral tunnel frown incision with both a horizontal and a running suture, and (4) posterior limbal acute beveled cataract incision with a running suture. All the incisions were placed in the vertical steep meridian.

RESULTS

Data were analyzed from 128 cases with 1-year follow-up. The results revealed that at the 2-month postoperative visit, preexisting astigmatism was significantly reduced in group 1 (P = .029) and significantly increased in groups 3 (P = .020) and 4 (P = .005). There was no significant change in group 2 (P = .06). By the 1-year postoperative visit, there was no significant difference in astigmatism from preoperative levels for all four groups. Vector analysis revealed no significant difference in the mean surgically induced cylinder at 1 year in all four groups. The number of eyes with induced against-the-rule astigmatism, however, was significantly higher than the number of eyes with induced with-the-rule astigmatism in all four groups (P <.01).

CONCLUSION

The authors found that sutured wounds placed in the vertical steep meridian may initially increase with-the-rule astigmatism, whereas nonsutured wounds placed in the vertical steep meridian may initially reduce with-the-rule astigmatism. By 1 year, however, a mean flattening of the vertical steep meridian was observed in the three groups with sutures as well as in the group without sutures.

Sex determination by polymerase chain reaction on mummies discovered at Taklamakan desert in 1912

Sex determination was performed by the polymerase chain reaction (PCR) on eight adult mummies and one child mummy which were discovered at Taklamakan desert in 1912 and now belong to the Lüshun Museum in China. Archaeologically, these mummies were humans living in the seventh century, that is, more than 1300 years ago. Putative sex determination was performed based on external morphology for six of the eight adults, but it was impossible for the other two adults and one child mummy due to marked destruction on the external morphology. Hair, muscle and skin samples were then collected from each adult mummy, and skin and rib samples from the child mummy. Forty PCR cycles were performed as follows: denaturation at 94 degrees C for 40 s, annealing at 55 degrees C for 30 s and extension at 72 degrees C for 1 min. The primer and PCR reaction mixture were prepared according to the report by Witt and Erickson (M. Witt and R. P. Erikson, A rapid method for detection of Y-chromosomal DNA from dried blood specimens by the polymerase chain reaction. Hum. Genet., 82 (1989) 271-274)). Two different pairs of primer were used. One was X1, X2 (X1: 5'-AATCATCAAATGGAGATTTG-3'; X2: 5'-GTTCAGCTCTGTGAGTGAAA-3') to flanking the 170 bp fragment of the alphoid repeats on the human X chromosome, and the other was Y11, Y22 (Y11: 5'-ATGATAGAAACGGAAATATG-3'; Y22: 5'-AGTAGAATGCAAAGGGCTC-3') to flanking the 130 bp fragment of the alphoid repeats on the human Y chromosome. Extracted DNA solutions from mummy samples was purified using a spin column (T. Yoshii, K. Tamura, T. Taniguchi, K. Akiyama and I. Ishiyama, Water-soluble eumelanin as a PCR-inhibitor and a simple method for its removal. Jpn. J. Legal Med., 47 (1993) 323-329 (in Japanese with English abstract) for removing PCR-inhibitors, and bovine serum albumin (BSA) was employed to inhibit the remaining impurities even after the purification with the column. In six adult cases where the putative sex was determined from external morphology, the sex in five cases was consistent with that by PCR using hair, muscle, and skin samples, but the other one was inconsistent. In two adult cases where sex estimation was externally impossible, the sex was determined to be male because both X-specific and Y-specific bands were clearly detected. The child mummy was definitely male. This study shows that the sex determination was possible by the PCR method even with very ancient human samples > 1300 years old, that spin column was useful for removing impurities in the DNA solution from ancient human samples and that the BSA of optimum concentration suppressed the action of the PCR-inhibitory factors.

[The study of growth factors in human colostrum]

OBJECTIVE

To characterize and identify the growth factors in human colostrum and to evaluate the importance of breast-feeding.

METHODS

The activity of growth factors in human colostrum was determined by technique of 3H-TdR incorporation into cultured NIH-3T3 cells. The acid growth factor (CAGF) and basic growth factor (CBGF) were purified from human colostrum by a sequence of chromatography. The study of stability and SDS-PAGE was applied to identify the CAGF and CBGF.

RESULTS

0.5% (v/v) of human colostrum and 3.0% (v/v) of bovine serum had the same activity in stimulating DNA synthesis. The specific activity of human colostrum in stimulating DNA synthesis was 20 times greater than that of bovine serum. The activity of growth factors in human colostrum was higher than that in human milk or bovine colostrum, and only human colostrum contained two different kinds of growth factors--CAGF and CBGF.

CONCLUSIONS

Human colostrum contains two kinds of growth factors. CAGF is epidermal growth factor like (EGF-like) growth factor and the CBGF is platelet differentiation growth factor like (PDGF-like) growth factor. The effects of human colostrum on promoting baby growth and development is stronger than that of human milk and bovine colostrum.

[Increased expression of platelet-derived growth factor beta receptor gene in hypoxic rat lungs]

The changes of platelet-derived growth factor (PDGF) beta receptor gene expression in hypoxic rats lungs was examined. Northern blots analysis revealed that normal lungs expression PDGF-beta receptor mRNA, with the longer of hypoxia the level of the mRNA increased rapidly. It reached a maximum at day 4, and was 1.34 fold as compared with the control (P < 0.05). Immunohistochemistry investigation showed that PDGF-beta receptor mainly distributed on smooth muscle cells and endothelial cells of middle and small arterial trees in rat lung. With hypoxia, the distribution of PDGF-beta receptors did not change, but it was more intense and reached a maximum at day 7, and was 2.40 fold as compared with the control (P < 0.05). The results suggested that increased expression of PDGF receptor gene may play a role in hypoxic pulmonary vascular remodeling.

The role of self peptides in the allogeneic cross-reactivity of CTLs

This study presents data relevant to understanding the molecular and structural basis for the cross-reactivity of many CTLs on multiple MHC targets. Five anti-H-2Kb alloreactive CTL clones derived from B6.C-H-2bm1 (bm1), B6.C-H-2bm8 (bm8), and B6.C-H-2bm11 (bm11) mice and a Sendai virus-specific H-2Kb-restricted CTL clone were studied. Self peptides extracted from Kb molecules were fractionated by HPLC and tested for their ability to be recognized on RMA/s (H-2b) cells by those clones. For each alloreactive clone, a single dominant peptide peak was found to sensitize target cells. In addition to recognizing peptides presented by the Kb molecule, the five alloreactive clones and the one Sendai virus-specific clone all showed cross-reactivities on a panel of Kbm mutant cells in a peptide-dependent manner. Two CTL clones, one alloreactive and one virus specific, cross-recognized Kbm targets by each responding to a unique self peptide in the context of the mutant MHC molecules. Our data underscore the prevalent idea that TCR-alpha beta have an inherent structural capability to react with several peptide/MHC structural patterns other than the original peptide/MHC pattern that might have been used to select that TCR. The high incidence of cross-reactivity seems to reflect a feature of the mechanism of positive selection in the thymus and the need for T cells in the repertoire to have an expanded capability for responding to a wide variety of foreign Ags.

The role of self peptides in the allogeneic cross-reactivity of CTLs

This study presents data relevant to understanding the molecular and structural basis for the cross-reactivity of many CTLs on multiple MHC targets. Five anti-H-2Kb alloreactive CTL clones derived from B6.C-H-2bm1 (bm1), B6.C-H-2bm8 (bm8), and B6.C-H-2bm11 (bm11) mice and a Sendai virus-specific H-2Kb-restricted CTL clone were studied. Self peptides extracted from Kb molecules were fractionated by HPLC and tested for their ability to be recognized on RMA/s (H-2b) cells by those clones. For each alloreactive clone, a single dominant peptide peak was found to sensitize target cells. In addition to recognizing peptides presented by the Kb molecule, the five alloreactive clones and the one Sendai virus-specific clone all showed cross-reactivities on a panel of Kbm mutant cells in a peptide-dependent manner. Two CTL clones, one alloreactive and one virus specific, cross-recognized Kbm targets by each responding to a unique self peptide in the context of the mutant MHC molecules. Our data underscore the prevalent idea that TCR-alpha beta have an inherent structural capability to react with several peptide/MHC structural patterns other than the original peptide/MHC pattern that might have been used to select that TCR. The high incidence of cross-reactivity seems to reflect a feature of the mechanism of positive selection in the thymus and the need for T cells in the repertoire to have an expanded capability for responding to a wide variety of foreign Ags.

Expression of a multidrug resistance gene in human rheumatoid synovium

The objective of this study was to assess the expression of a multidrug resistance (MDR) phenotype, implicated in the cellular resistance of tumor to chemotherapy, in rheumatoid synovial membrane. Synovial membrane from 16 rheumatoid (RA) patients was studied. Six patients with osteoarthritis constituted the control group. The cell membrane expression of the glycoprotein Pgp 170, encoded by the MDR 1 gene, was determined by an immunoperoxidase technique using two different monoclonal antibodies (JSB 1, C 219). The polymerase chain reaction (PCR) methods were used in parallel to detect the presence of the MDR 1 gene mRNA in the synovial cells. Pgp 170 was expressed on the cell membrane of five RA patients and MDR 1 cellular transcription was detected in one other RA patient. We did not observe any association between synovial glycoprotein expression and age, disease activity, and a specific treatment with a long-acting drug. However, MDR protein expression was associated with the successive treatment with more than three disease-modifying antirheumatic drugs (DMARDs). We concluded that the synovial membrane expresses a glycoprotein recognized by the antibodies JSB 1 and C 219. The absence of concomitant MDR 1 transcription suggests the expression of an atypical MDR phenotype in the synovial membrane, distinct from the Pgp 170 encoded by the MDR 1 gene. The implications of the MDR phenotype and the resistance of RA to DMARDs is further discussed.

Transmissible retrovirus in Epstein-Barr virus-producer B95-8 cells

Epstein-Barr virus (EBV) released from the B95-8 marmoset cell line has served as a prototype for biologic and biochemical studies of EBV. Here we identify and characterize a retrovirus carried by many cultures of B95-8 cells. The experiments were stimulated by the isolation of a cDNA clone from B95-8 cells in which sequences from the EBV large internal repeat were linked to gag sequences similar to those of squirrel monkey retrovirus, human isolate, SMRV-H. However, among 413 amino acids predicted from the nucleotide sequence of the gag region of the B95-8 SMRV isolate there were 48 amino acid changes that distinguished this virus from SMRV-H originally isolated from a human lymphoid cell line by Oda et al. (1988, Virology 167, 468-476). Nucleic acid and antibody probes were developed for the B95-8 isolate of SMRV. Using such probes, we found that SMRV-B95-8 was readily transmissible, independent of EBV, as an infectious virus to human B and T cell lines. SMRV-B95-8 was highly fusogenic in the presence or absence of EBV. The ultrastructural appearance of the B95-8 retrovirus was characteristic of a type D retrovirus. Cells dually infected with EBV and SMRV-B95-8 did not demonstrate increased levels of lytic EB viral replication. SMRV-B95-8 did not by itself cause lymphocyte immortalization or enhance immortalization by EBV. Thus SMRV-B95-8 does not contribute to the major biologic properties of the B95-8 strain of EBV.