Hypereosinophilic Syndrome with Endomyocarditis: Identification by Next-Generation Sequencing of the JAK2-V617F Mutation

Hypereosinophilic syndrome requires a peripheral absolute eosinophil count of ≥1.5 × 109 /L with clinical manifestations attributable to peripheral or tissue hypereosinophilia. Clinical manifestations can vary greatly, with the majority of patients relatively asymptomatic and the eosinophilia detected incidentally. However, in a minority of hypereosinophilia cases, they may present with severe lifethreatening organ dysfunction affecting skin, lung, heart, gastrointestinal tract, and nervous system. A case of hypereosinophilia with potentially life-threatening cardiovascular involvement is discussed. Initial laboratory investigations showed an elevated white blood cell count with 60% eosinophils. An endomyocardial biopsy revealed eosinophilic endomyocarditis with granuloma, rare giant cells, and no vasculitis, microorganisms, or malignancy. Her presentation met the criteria for either hypereosinophilic syndrome or eosinophilic granulomatosis with polyangitis. Molecular genetic analysis was negative for myelodysplastic syndrome panel/ Platelet Derived Growth Factor Receptor Beta (PDGFRB) (5q32)/Fibroblast Growth Factor Receptor 1 (FGFR1) Fluorescence In Situ Hybridization (FISH), Feline McDonough Sarcoma-related Tyrosine Kinase 3 (FLT3) Internal Tandem Duplication (ITD) mutation, Calregulin (CALR) exon 9 mutation, and T-cell gene rearrangement/polymerase chain reaction. Bone marrow biopsy revealed a mildly hypocellular marrow with multilineage hematopoiesis,+ megakaryocyte dysplasia, and focal eosinophilia. No excess blasts, no monotypic B-cell population, and no discrete pan T-cell aberrancies were found. Bone marrow cytogenetic studies showed a normal signal pattern for myeloproliferative neoplasms panel/Sec1 Family Domain Containing 2 (SCFD2)-Ligand of Numb Protein-X (LNX)-Platelet-derived Growth Factor Receptor Alpha (PDGFRA) fluorescence in situ hybridization with a normal karyotype of 46 XX. Next-generation sequencing, however, was positive for the JAK2-V617F mutation, a rare molecular abnormality in hypereosinophilic syndrome. The prevalence ranges from approximately 0% to 4%. The JAK2 point mutation leads to aberrant tyrosine phosphorylation and increased cytokine activation. The case demonstrates the complexity and challenging nature of advanced diagnostic opportunities in hypereosinophilia and the potential use, in select subsets, of targeted treatments such as tyrosine kinase inhibitors.

Female-to-male sex pheromones of low volatility in the Asian elephant,Elephas maximus

In their natural ecosystems, the sexes of Asian elephants,Elephas maximus, live separately. For several weeks prior to ovulation, the urine and cervical mucus of female Asian elephants contain extractable chemical agents of low volatility that elicit a high frequency of flehmen responses from bull elephants as an integral part of mating. Subsequent to flehmen responses, male sexual arousal occurs and, if the female is available, mating results. During the course of our project to determine the agent(s) and describe the responses associated with female to male sexual communication, we have identified an unusual compound. This compound, apparently the sole component of the active fraction, was identified by mass, proton nuclear magnetic resonance, ultraviolet/visible, and infrared spectrometries as indolo-[2,1-b] quinazoline-6,12-dione (tryptanthrine). Exhaustive and repetitive bioassays established that pure authentic (synthetic) tryptanthrine was not the compound responsible for the bioresponse. Rather a coeluting minor component, also of low volatility, elicited the male bioresponse.

Influence of Practice Schedule on Testing Schema Theory Predictions in Adults

Since the publication of Schmidt's (1975) schema theory of motor learning, numerous studies have assessed the variability of practice hypothesis. Of these, only research using children as subjects has provided consistent results. Findings from adult studies have been equivocal. Two experiments were conducted to assess the possibility that the schedule of variable practice during acquisition may be a clue to this equivocality, since only experiments (using adults as subjects) that have provide random variability of practice conditions have consistently supported the tenets of schema theory. Using a two movement rapid timing task, subjects learned to control their actions under one (constant) or four (variable) parameters, with variable practice conducted under either a blocked or a randomized schedule. Results for variable error and absolute constant error showed that random-variable practice provided strong support for the schema theory prediction, whereas blocked-variable practice provided only relatively weak support. Two contrasting implications of these results are discussed with respect to support versus non-support for Schmidt' schema theory.

The acute effects of synthetic intravenous Delta9-tetrahydrocannabinol on psychosis, mood and cognitive functioning

BACKGROUND

Recent work suggests that heavy use of cannabis is associated with an increased risk of schizophrenia-like psychosis. However, there is a dearth of experimental studies of the effects of the constituents of cannabis, such as Delta9-tetrahydrocannabinol (THC). In a study of intravenous (i.v.) synthetic THC in healthy humans, we aimed to study the relationship of the psychotic symptoms induced by THC to the consequent anxiety and neuropsychological impairment.

METHOD

Twenty-two healthy adult males aged 28+/-6 years (mean+/-s.d.) participated in experimental sessions in which i.v. THC (2.5 mg) was administered under double-blind, placebo-controlled conditions. Self-rated and investigator-rated measurements of mood and psychosis [the University of Wales Institute of Science and Technology Mood Adjective Checklist (UMACL), the Positive and Negative Syndrome Scale (PANSS) and the Community Assessment of Psychic Experiences (CAPE)] were made at baseline and at 30, 80 and 120 min post-injection. Participants also completed a series of neuropsychological tests [the Rey Auditory Verbal Learning Task (RAVLT), Digit Span, Verbal Fluency and the Baddeley Reasoning Task] within 45 min of injection.

RESULTS

THC-induced positive psychotic symptoms, and participant- and investigator-rated measurements of these were highly correlated. Participants showed an increase in anxiety ratings but there was no relationship between either self- or investigator-rated positive psychotic symptoms and anxiety. THC also impaired neuropsychological performance but once again there was no relationship between THC-induced positive psychotic symptoms and deficits in working memory/executive function.

CONCLUSIONS

These findings confirm that THC can induce a transient, acute psychotic reaction in psychiatrically well individuals. The extent of the psychotic reaction was not related to the degree of anxiety or cognitive impairment.

Antigen expression of frozen platelets

Platelet antigens of platelet samples from 36 donors, frozen for different intervals, were evaluated by the platelet suspension immunofluorescence test (PSIFT). A, B, PLA1(HPA-1a) and various HLA antigens were tested by their corresponding antisera. The antigen could be detected in almost all the samples after one month of freezing. After 3 and 6 months, the platelet antigens could only be detected in 29.2% and 3.7% of the samples, respectively. There was no difference in decay of antigen expression among A, B, PLA1 and HLA antigens. When compared with the freshly prepared platelets, frozen platelets presented stronger antigen expression after 2 to 4 weeks of storage. This may suggest that the frozen platelets could be used for platelet crossmatching procedures without loss of their antigenicity within one month.

The effect of acidified glucose nutrient solution on preservation of platelet concentrate

The preservation effect of a new platelet solution--acidified glucose nutrient solution (AGN)--was tested by adding AGN to pooled platelet rich plasma (PRP) prior to preparation of platelet concentrates (PC). Each PRP unit was prepared from a unit of whole blood and four PRP of the same blood group were pooled in 400 ml volume PVC bags. Equal aliquots of each pooled PRP were made prior to preparation of PC. AGN was added to one aliquot and nothing was added to the control aliquot. Equal volume and concentration PC were then prepared and the PC were further aliquoted for storage at 22 degrees C. After five days, the parameters of platelet count, pH, aggregability and hypotonic shock response (HSR) for PC preserved in AGN plasma were better than those of the controls preserved in normal ACD plasma. The aggregability and HSR of AGN platelet concentrates recovered to baseline after two h of incubation with fresh plasma. The results of electron microscopy show that platelets preserved in AGN have less changes in morphology. The results of our work suggest that the preservation effect of AGN on PC is similar to the effect of using second generation containers or preparation of platelets from thrombocytapheresis.

Protein identification using a quadrupole ion trap mass spectrometer and SEQUEST database matching

A procedure is described for rapid, sensitive protein identification utilizing liquid chromatography--tandem mass spectrometry. The analysis is performed on mixtures of peptides obtained by enzyme digestion. The SEQUEST computer program is used to match the sequence information in the spectra to a database of known protein sequences.

Validation of high-performance liquid chromatographic-mass spectrometric method for the analysis of lidocaine in human plasma

A sensitive and simple liquid chromatography-tandem mass spectrometry method is developed and validated for the determination of lidocaine in human plasma. Bupivacaine is used as an internal standard, and the plasma extraction is performed by a simple liquid-liquid extraction. The limit of quantitation (LOQ) is 0.5 ng/mL with a signal-to-noise ratio greater than 5. The calibration curve is linear from 0.5 to 250 ng/mL with an r2 greater than 0.99. The coefficients of variation for within- and between-assay imprecision, including LOQ, are < or = 13% and < or = 8%, respectively. The percentage of inaccuracy for within- and between-assay, including LOQ, are < or = 9% and < or = 5%, respectively. The absolute recovery of lidocaine and bupivacaine are greater than 84% and 82%, respectively. The higher sensitivity and accuracy of this method allow the measurement of low concentrations of lidocaine in plasma from a clinical study of topically applied lidocaine in healthy subjects.

Encoding specificity: a reply to Croker (1981)

Crocker's (1981) comment on the Lee and Hirota (1980) paper essentially raises two issues. First, objection is made to the applicability of the encoding specificity principle to the resuits found in our study. Second, on a more general level, Crocker questions the heuristic value of utilizing theoretical issues in non-motor domains to guide scientific experimentation in the study of motor behavior. In this reply I posit that Crocker's reservations about encoding specificity are based upon improper theoretical and methodological considerations. Regarding the more philosophical issue however, I argue that Crocker's view may be counterproductive to progress in the area of memory research.

The relative proportions of sirolimus metabolites in blood using HPLC with mass-spectrometric detection

Measurement of sirolimus in blood as a guide to dose adjustment is an accepted practice. To date, most data have resulted from the use of a chromatographic technique. With the imminent introduction of an immunoassay into this field, there is a need to know whether metabolites that could interfere with the performance of this assay, causing a bias compared with measurements made by a chromatographic assay, vary over a period of time or with changes in concomitant immunosuppressive therapy. This preliminary study measured several sirolimus metabolites in blood samples from a variety of clinical settings, using high-performance liquid chromatography with tandem mass-spectrometric detection. Two metabolites known to cross-react in one immunoassay system, single hydroxylation products and 41-O-demethyl rapamycin, were found to constitute the bulk of the metabolic products. They were also found to form a remarkably stable proportion of all metabolites measured, both with respect to the time since transplantation and the concomitant use of cyclosporine or tacrolimus. It is concluded that the analytical bias due to cross-reactivity with metabolites, inherent in this immunoassay, should be consistent across a wide spectrum of patients receiving the drug.

Therapeutic monitoring of sirolimus: its contribution to optimal prescription

It is now common practice to measure immunosuppressive drugs in blood as a guide to therapy. The immunosuppressive drug sirolimus, recently approved for use following kidney transplantation, was developed in the context of this clinical approach. Throughout the early clinical studies, validated analytical techniques based on chromatographic techniques were used to measure the drug. After a brief period in which an immunoassay was available, routine measurements are again being performed by chromatographic assays. In this article the use of blood concentration measurements in the assessment of the early and pivotal clinical trials of the drug is documented. Then, the rationale for the routine monitoring of the drug in clinical practice, a regulatory requirement in some countries, is set out. It is concluded that the development of this compound has benefited from experience gained during the pharmacokinetic assessment of other immunosuppressive drugs. The pharmacokinetic data accumulated on sirolimus have been a key element in formulating guidelines on dosing with this drug, both when used in combination with cyclosporine and when used after cyclosporine withdrawal.

The association of HLA -A, -B, and -DRB1 genotypes with Graves' disease in Taiwanese people

Graves' disease has been associated with different human leukocyte antigen (HLA) genes in different races. To evaluate the association of HLA type in Taiwanese with Graves' disease, the HLA-A, -B, and -DRB1 alleles in a total of 236 Taiwanese adults with Graves' disease and 533 racially matched normal control subjects were examined using the PCR-SSOP (sequence specific oligonucleotide probe) technique. The prevalence of HLA-A*0207, -B*2704, -B*4601, and -DRB1*0901 among patients with Graves' disease was found to be increased, with odds ratios (OR) of 2.21, 3.82, 1.76 and 1.62, respectively. However, after correction for multiple comparisons, the relative risk of HLA-A*0207 susceptibility to Graves' disease remained statistically significant and the haplotype HLA-A*3303 -B*5801 -DRB1*0301 had a significantly protective effect. None of the other 2- or 3-locus haplotypes showed any significantly increased risk. Although HLA-DRB1*1405 showed an increased relative risk in patients with GO (Graves' opthalmopathy) (OR 4.61) when compared with patients without GO, the relative risk after adjusting for the number of comparisons was not significant. Taiwanese patients with Graves' disease have HLA-associated susceptibility genes which are similar to those found in Chinese patients in Hong Kong and Singapore. However, the finding in this study of a higher frequency of HLA-A*0207 in Taiwanese with Graves' disease has not been documented in any other ethnic group.

Low frequency of HLA-B*2706 in Taiwanese patients with ankylosing spondylitis

The presence of HLA-B27 in patients affected with ankylosing spondylitis (AS) was well established prior to the advent of DNA typing of various genes within the major histocompatibility complex (MHC) in humans. However, molecular typing of the MHC genes revealed that B27 comprises a motley assortment of alleles, some of which are strongly positively associated with the disease and some of which are negatively associated with the disease. B*2706 was reported to have a negative association with AS in the Thai population and in Chinese Singaporeans. We report here our finding of an absence of B*2706 in 184 Taiwanese AS patients.

Biochemical and genetic analyses of the U5, U6, and U4/U6 x U5 small nuclear ribonucleoproteins from Saccharomyces cerevisiae

We have purified the yeast U5 and U6 pre-mRNA splicing small nuclear ribonucleoproteins (snRNPs) by affinity chromatography and analyzed the associated polypeptides by mass spectrometry. The yeast U5 snRNP is composed of the two variants of U5 snRNA, six U5-specific proteins and the 7 proteins of the canonical Sm core. The U6 snRNP is composed of the U6 snRNA, Prp24, and the 7 Sm-Like (LSM) proteins. Surprisingly, the yeast DEAD-box helicase-like protein Prp28 is stably associated with the U5 snRNP, yet is absent from the purified U4/U6 x U5 snRNP. A novel yeast U5 and four novel yeast U4/U6 x U5 snRNP polypeptides were characterized by genetic and biochemical means to demonstrate their involvement in the pre-mRNA splicing reaction. We also show that, unlike the human tri-snRNP, the yeast tri-snRNP dissociated upon addition of ATP or dATP.

HLA-DRB1 antigens in Taiwanese patients with juvenile-onset systemic lupus erythematosus

OBJECTIVE

This study was done to investigate the frequency of HLA-DRB1 antigens in juvenile-onset systemic lupus erythematosus (SLE) in the Taiwanese population.

PATIENTS AND METHODS

Thirty-four Taiwanese patients with juvenile onset SLE and 200 unrelated healthy controls were studied. HLA-DRB1 typing was performed with polymerase chain reaction (PCR) and the sequence-specific oligonucleotide probe (SSO) typing method.

RESULT

Among the 14 investigated DRB1 alleles, the frequency of HLA-DRB1*1602 was higher in juvenile onset SLE patients than the controls (15.15% vs 4.50%, odds ratio 3.66, 95% confidence interval 1.15-11.68, Pc = 0.04). Although there were differences in the frequencies of DRB1*0301, DRB1*0803, and DRB1*1501 between patients and controls, the associations were statistically insignificant.

CONCLUSION

The frequency of HLA-DRB1*1602 was significantly higher in patients with juvenile onset SLE than in healthy controls. This finding differs from those in the previous studies in Caucasian and Japanese adult onset SLE patients.

Prevention of allograft heart valve failure in a rat model

OBJECTIVE

Allograft heart valves are commonly used in cardiac surgery. Despite mounting evidence that these valves are immunogenic, leading to premature failure, current clinical practice does not attempt to minimize or control such a response. The objective of this study was to evaluate immune modulatory approaches to ameliorate allograft valve failure in a rat model.

METHOD

Aortic valve grafts were implanted infrarenally into Lewis rat recipients (n = 32). There were 4 transplant groups: syngeneic grafts (Lewis to Lewis), untreated allografts (Brown Norway to Lewis), allograft recipients treated with cyclosporine (INN: ciclosporin) (10 mg/kg per day for 7 or 28 days), and allograft recipients treated with anti-alpha4 integrin and anti-beta2 integrin monoclonal antibodies for 7 days. At 7 and 28 days the valves were examined for structural integrity and cellular infiltration.

RESULTS

Both cyclosporine and anti-alpha4/beta2 integrin treatment resulted in significant reduction in leaflet infiltration by macrophages (ED1(+)), T cells (CD3(+)), and CD8(+) T cells at 7 days with preservation of structural integrity when compared with control allografts. Twenty-eight days after implantation, daily treatment with cyclosporine preserved leaflet structural integrity and inhibited cellular infiltration. However, a short course of cyclosporine (7 days) failed to prevent destruction of the valves at 28 days.

CONCLUSIONS

Immune modulatory approaches aimed at T-cell activation or trafficking decrease leaflet cellular infiltration and prevent allograft valve structural failure. However, short-course therapy does not appear to be sufficient and must be maintained to allow long-term preservation of leaflet structural integrity (28 days).

Oral exposure to alloantigen generates intragraft CD8+ regulatory cells

We have previously reported that oral administration of allogeneic rat spleen cells before kidney allotransplantation significantly prolongs graft survival. This prolongation was alloantigen specific and was associated with a decrease in graft-infiltrating cells (GIC) and an increase in transcription of IL-4 mRNA in the GIC. In this study increased splenic mixed lymphocyte responses from animals orally exposed to alloantigen before kidney transplantation suggested that the kidney allograft prolongation was not due to a masking of allorecognition, but to an immunomodulation of the immune response. We have assessed GIC T cell subsets on day 5 post-transplant and found decreased numbers of CD4(+) T cells in fed animals compared with controls, but there was no change in CD8(+) T cell numbers. The CD8(+) GIC from fed animals transcribed substantial levels of perforin, granzyme, and Fas ligand mRNA, indicating the presence of active CTL. Direct CTL assays showed that the GIC from fed recipients exhibited higher allo-CTL activity than GIC from control unfed recipients. In addition, the CD8(+) GIC exhibited high levels of IL-4 mRNA, suggesting Tc2-type regulatory cells. Prolonged graft survival in the face of active CTL and Tc2 cells suggests the presence of a CD8(+) regulatory cell population in the allograft. To confirm this, cell transfer experiments were performed. Prolongation of graft survival was transferred from rats orally exposed to alloantigen to naive animals by transfer of CD8(+) GIC. This is the first report that oral exposure to alloantigen prolongs kidney allograft survival by the generation of intragraft CD8(+) regulatory cells.

Interaction of 11-cis-retinol dehydrogenase with the chromophore of retinal g protein-coupled receptor opsin

Vertebrate opsins in both photoreceptors and the retinal pigment epithelium (RPE) have fundamental roles in the visual process. The visual pigments in photoreceptors are bound to 11-cis-retinal and are responsible for the initiation of visual excitation. Retinochrome-like opsins in the RPE are bound to all-trans-retinal and play an important role in chromophore metabolism. The retinal G protein-coupled receptor (RGR) of the RPE and Müller cells is an abundant opsin that generates 11-cis-retinal by stereospecific photoisomerization of its bound all-trans-retinal chromophore. We have analyzed a 32-kDa protein (p32) that co-purifies with bovine RGR from RPE microsomes. The co-purified p32 was identified by mass spectrometric analysis as 11-cis-retinol dehydrogenase (cRDH), and enzymatic assays have confirmed the isolation of an active cRDH. The co-purified cRDH showed marked substrate preference to 11-cis-retinal and preferred NADH rather than NADPH as the cofactor in reduction reactions. cRDH did not react with endogenous all-trans-retinal bound to RGR but reacted specifically with 11-cis-retinal that was generated by photoisomerization after irradiation of RGR. The reduction of 11-cis-retinal to 11-cis-retinol by cRDH enhanced the net photoisomerization of all-trans-retinal bound to RGR. These results indicate that cRDH is involved in the processing of 11-cis-retinal after irradiation of RGR opsin and suggest that cRDH has a novel role in the visual cycle.

Introducing samples directly into electrospray ionization mass spectrometers using microscale capillary liquid chromatography

This unit describes the design and operation of a microscale electrospray (ES) interface suitable for the on-line liquid chromatography (LC) separation and mass spectrometry (MS) analysis of mixtures of peptides and proteins. The interface utilizes an ES needle packed with reversed-phase support. Such a design has the advantage of minimizing any void volume between the end of the column and point of electrospray ionization, thus maintaining the integrity of the LC separation and maximizing sensitivity. Here, protocols are presented for construction of an integrated LC column ES needle in-house, packing the ES needle, and mounting and using the microscale ES LC/MS interface assembly. Various options for low-flow solvent delivery systems are also discussed.

MoWeD, a computer program to rapidly deconvolute low resolution electrospray liquid chromatography/mass spectrometry runs to determine component molecular weights

A computer program is described that can rapidly process low-resolution electrospray liquid chromatography/mass spectrometry (LC/MS) for peptides and proteins and assign molecular weights for observed components. The program first analyzes individual scans using a deconvolution algorithm similar to that previously described by Zhang and Marshall. Results for the entire run are then sorted by mass and those values found in adjacent scans are grouped together. The list of found components can also be compared to a user defined list of target molecular weight values making it easy to compare the results from different analyses. The program also has the capability to process a rolling average of scans that improves the performance when analyzing high molecular weight components. Other program features facilitate closer examination of selected spectra or regions of the chromatogram to check the MoWeD mass assignments. The utility of the program was demonstrated by the analysis of LC/MS data derived from a complex mixture of proteins derived from a bacterial whole cell lysate that had previously been analyzed manually. The MoWeD analysis was 30 times faster and provided a more comprehensive list of the components present.

MUC4 (sialomucin complex) expression in salivary gland tumors and squamous cell carcinoma of the upper aerodigestive tract

OBJECTIVES

This study investigates MUC4 expression in normal squamous epithelia and squamous cell carcinoma (SCC) of the upper aerodigestive tract (UADT), and in salivary gland neoplasms.

STUDY DESIGN

MUC4 antigens in tumor and adjacent normal tissue are localized by immunocytochemical studies. Fresh frozen tissues from surgical resection specimens are further analyzed by Western blot.

RESULTS

MUC4 is identified by immunocytochemical staining throughout the normal UADT mucosa, in 34 of 40 primary UADT SCC, and in 11 of 12 metastatic cervical lymph nodes. A trend toward decreased MUC4 staining in moderately and poorly differentiated tumors is noted. Immunoblots show MUC4 in 4 of 5 SCC analyzed. Immunocytochemical staining of MUC4 in 13 major and minor salivary gland neoplasms reveal variable staining of normal and neoplastic tissue. MUC4 is demonstrated in immunoblots of normal parotid tissue and in the single parotid malignancy analyzed, but is not demonstrated in one minor salivary gland malignancy. These findings characterize normal UADT mucosal and salivary MUC4 expression, and MUC4 expression in SCC of the UADT and in salivary gland tumors.

SIGNIFICANCE

Correlation of MUC4 expression with clinical outcomes may establish MUC4 as a potential molecular prognostic marker for these tumors.

The dendritic cell cytoskeleton is critical for the formation of the immunological synapse

The binding of a T cell to an APC results in T cell actin cytoskeletal rearrangement leading to the formation of an immunological synapse. The APC cytoskeleton has been thought to play a passive role in this process. In this study, we demonstrate that dendritic cells (DC), unlike other APC, actively polarize their actin cytoskeleton during interaction with T cells. DC cytoskeletal rearrangement was critical for both the clustering and the activation of resting T cells. This study provides compelling evidence that the APC cytoskeleton plays an active role in the immunological synapse and may explain the unique ability of DC to activate resting T cells.

Fascin is involved in the antigen presentation activity of mature dendritic cells

Maturation of dendritic cells (DC) is critical to their development into potent APCs. Upon maturation, DC up-regulate the expression of MHC class II as well as costimulatory and adhesion molecules, all of which are important in Ag presentation. In addition, they undergo structural changes characterized by the expression of numerous long dendrites. Fascin is an actin-bundling protein that has been reported to be important for the development of dendrites. In this study, we evaluated fascin expression and function during DC maturation into potent APC. In vitro, treatment of bone marrow-derived DC (BM-DC) with GM-CSF resulted in increased levels of fascin expression. This increase correlated directly with an increase in MHC class II and B7-2 expression. Fascin expression was decreased by the addition of TGF-ss and increased by the addition TNF-alpha to the culture. These cytokines suppress or enhance DC maturation, respectively. Increased levels of fascin expression were found to correlate with increased APC activity in a one-way MLR. Specific inhibition of fascin expression, using antisense oligonucleotides, markedly reduced this APC allostimulatory activity. These data demonstrate that fascin expression correlates with DC maturation into APC, and it plays a significant role in the ability of DC to function as APC. This observation is the first evidence linking fascin-mediated dendrite formation with the APC activity of DC.

Cryopreservation of rat aortic valves results in increased structural failure

BACKGROUND

The cause of valve allograft failure is most likely multifactorial and may include mechanical, immunological, and other factors. Cryopreservation of these valves is often used to extend storage times. However, there has been considerable confusion as to the effects of cryopreservation on valve durability. Our objective was to determine the effects of cryopreservation on histopathological changes in rat aortic valve grafts.

METHODS AND RESULTS

Syngeneic rat aortic valve grafts (Lewis to Lewis; n=24) and allogeneic rat aortic valve grafts (Brown Norway to Lewis; n=24) were implanted infrarenally, either fresh or after cryopreservation. At 7, 14, and 28 days, the valves were explanted, and histological and immunohistochemical examinations were performed in a blinded fashion. Fresh syngeneic graft leaflets retained their normal structure for the 28-day period of observation. Cryopreserved syngeneic grafts showed retrovalvar thrombus formation, with leaflet destruction at 7, 14, and 28 days. Fresh allogeneic graft leaflets showed significant leaflet thickening and progressive destruction at 14 and 28 days. Cryopreserved allogeneic grafts had evidence of retrovalvar thrombus formation with leaflet destruction at 7, 14, and 28 days. Cryopreserved syngeneic grafts resulted in significant infiltration of mononuclear (ED1(+)) cells not seen with fresh syngeneic grafts but similar to fresh allogeneic grafts. All allogeneic grafts resulted in significant infiltration of T-lymphocytes (CD3(+), CD8(+), CD43(+)).

CONCLUSIONS

Cryopreservation appears to predispose syngeneic and allogeneic rat aortic valve leaflets to accelerated injury and destruction. This mode of failure resembles that of fresh allogeneic valve grafts.

Modulation of B-cell proliferative response by a soluble extract of Nippostrongylus brasiliensis

We and others have previously shown that nematodes or nematode products can stimulate or inhibit the generation of lymphocyte responses, suggesting that nematodes exert diverse effects on the developing immune responses of their host. In this study we examined the immunomodulatory effect of a soluble extract of Nippostrongylus brasiliensis (adult worm homogenate [AWH]) on B-cell responsiveness. We found that the extract inhibited the proliferation of B cells to lipopolysaccharide (LPS) stimulation in a dose-dependent manner. This effect was specific to B cells, since the extract did not inhibit T-cell proliferation to concanavalin A or anti-CD3 stimulation. The data presented here confirm that the extract is not toxic to B cells. We present evidence that the active factor is proteinaceous in nature and that the inhibitory activity is restricted to the adult stage of Nb. The extract does not appear to interfere with early activation events since it can be added up to 48 h after LPS stimulation, and it inhibited responses to phorbol myristate acetate and ionomycin. Furthermore, the proliferation of B cells to other activators was also inhibited by AWH. This observation shows that the inhibitory activity of AWH is not restricted to LPS-mediated B-cell proliferation. We present evidence that, in the absence of accessory cells, the inhibitory effect of the extract was ablated. This observation shows that the activity of AWH is not mediated directly on B cells but is mediated via the production of negative signals from accessory cells (macrophages), which affect a downstream pathway required by all B-cell activators tested. These effects on B-cell and accessory cell function are likely to have a significant effect on the outcome of infections experienced concurrently.

Aortic valve graft implantation in rats: a new functional model

BACKGROUND

Allograft heart valves used in cardiac surgery often fail at an unacceptable rate. Immune mechanisms contribute to this failure, but adequate and functional small-animal valve models to characterize this phenomenon are lacking. The objective of this study was to create native aortic valve insufficiency in recipient rats to provide for a functional abdominal aortic valve graft implant.

METHODS

Lewis recipient rats underwent single-leaflet injury of their native aortic valve through a right carotid catheter injury. Animals were allowed to recover for 28 days, at which time a Lewis aortic valve graft was implanted infrarenally. Echocardiography with color flow Doppler scanning was performed before aortic injury, 1 week after aortic injury, and after abdominal implantation of a valve graft in animals with native aortic insufficiency.

RESULTS

After aortic valve injury, all animals had moderate-to-severe aortic insufficiency with a significant increase in diastolic and systolic left ventricular dimensions. Color flow Doppler scanning revealed diastolic aortic flow reversal from the aortic valve extending to the infrarenal abdominal aorta. Aortic valve grafts were then implanted infrarenally in animals with created aortic valve insufficiency and resulted in 100% patency and preservation of leaflets at 4 weeks after implantation. Leaflet motion of the abdominal graft was visualized by means of M-mode echocardiography.

CONCLUSION

Compensated native aortic insufficiency results in aortic diastolic flow reversal distal to the infrarenal aorta, thus allowing normal motion of the infrarenal allograft leaflets. This functional model will provide an opportunity to investigate the role of immunologic valve injury in the failure of valve allografts.

T lymphocytes mediate leaflet destruction and allograft aortic valve failure in rats

BACKGROUND

Allograft heart valves are commonly used in cardiac surgery but ultimately fail. This situation is most acute in children. This study addresses the role of T cell-mediated immune damage in allograft valve failure.

METHODS

Syngeneic (Lewis to Lewis) or allogeneic (Brown Norway to Lewis) aortic valve grafts were implanted infrarenally into Lewis rat recipients (n = 24). Allogeneic valve grafts were also implanted into T cell-deficient rats (nude; n = 12). At 7, 14, and 28 days the valves were explanted and examined for structural integrity and cellular infiltration.

RESULTS

Syngeneic grafts maintained normal leaflet structure with little leaflet immune infiltration. Allografts showed leaflet infiltration (7 days), significant leaflet thickening, progressively decreased cellularity (14 days), and leaflet destruction (28 days). Infiltrates contained CD43+, CD3+, and CD8+ cells. Allografts in T cell-deficient rats showed none of the above changes and maintained normal structural integrity.

CONCLUSIONS

Allograft heart valves in the rat model undergo T cell-mediated immune rejection, resulting in structural failure.

Extract of Nippostrongylus brasiliensis stimulates polyclonal type-2 immunoglobulin response by inducing De novo class switch

Infection with the nematode parasite Nippostrongylus brasiliensis induces a pronounced type-2 T-cell response that is associated with marked polyclonal immunoglobulin E (IgE) and IgG1 production in mice. To examine the differential roles of the infection and products produced by nematodes, we investigated a soluble extract of N. brasiliensis for the ability to mediate this type-2 response. We found that the extract induced a marked increase in IgE and IgG1 levels, similar to that induced by the infection. The extract did not affect the level of IgG2a in serum, showing that the effect was specific to IgE and IgG1 (type-2-associated immunoglobulin) rather than inducing a nonspecific increase in all immunoglobulin isotypes. This response was also associated with increased interleukin-4 production in vitro. These results confirm that the extract, like infection, is a strong inducer of polyclonal type-2 responses and a reliable model for investigating the regulation of nematode-induced responses. The extract induced the production of IgG1 when added to in vitro cultures of lipopolysaccharide-stimulated B cells. This provides evidence for the induction of class switch. It did not induce upregulation of IgG1 in naive (unstimulated) B cells or expand B cells in in vitro cultures. Analysis of DNA from the spleens of mice treated with the extract by digestion-circularization PCR demonstrated a marked increase in the occurrence of gamma1 switch region gene recombination in the cells in vivo. These results provide strong evidence that soluble worm products are able to mediate the marked polyclonal gamma1/epsilon response and that infection is not required to mediate this response. Furthermore, these data provide evidence that the soluble nematode extract induces this effect by causing de novo class switch of B cells and not by an expansion of IgG1 B cells or an increase in antibody production by IgG1 plasma cells.

An expert virtual instrument approach to the automated, data dependent MS/MS and LC/MS/MS analysis of proteins

Mass spectrometry has become an indispensable analytical tool for studies related to the structure and function of peptides and proteins. The variety of analytical methods, the range of instrument capabilities, and the complexity of the data obtained make it difficult for most laboratories to acquire the necessary expertise to make optimal use of their instrumentation.We describe an expert system approach to automating specific types of analyses in a way that makes it easier to transfer the capability to do specific experiments to other laboratories. Central to the approach is the creation of a computer program (ie, a virtual instrument) that controls the operation of physical components, analyzes incoming data, automatically adjusts instrument parameters to achieve the goal of the analysis, and reports the results. By interacting with the mass spectrometer through the computer operating system, it is possible to add useful functions to the system without altering any of the manufacturer-controlled data system software. The usefulness of this approach is illustrated by the automation of experiments to confirm the sequences of synthetic peptides and perform LC/MS/MS peak parking experiments and real-time database searches.

CD8+ T lymphocytes mediate destruction of the vascular media in a model of chronic rejection

Allograft arteriosclerosis is an important characteristic of chronic graft rejection. In allograft arteriosclerosis there is a striking loss of medial smooth muscle cells (SMCs) before the development of a concentric intimal proliferative response. In this study we evaluated the role of CD8+ T lymphocytes in this medial SMC loss. Brown Norway aortic segments were transplanted into Lewis animals for 60 days (long allo-exposure) or 20 days (short allo-exposure). After 20 days allogeneic exposure aortic segments were transplanted back into syngeneic (Brown Norway) animals for 40 days. Experimental animals were treated with mAb to CD8. Apoptosis was measured by terminal dUTP nick-end labeling at 20 days and morphometry analyzed at 60 days to evaluate medial and intimal changes. Anti-CD8 treatment significantly lowered CD8+ T cell counts in peripheral blood, reduced medial SMC apoptosis at 20 days, and increased medial SMC counts at 60 days. Both short- and long-allogeneic exposure groups confirmed these findings and demonstrated that medial SMC loss is proportional to the length of allogeneic exposure. Antibody depletion of CD8+ T cells results in reduced medial SMC apoptosis and better medial SMC preservation. This supports the hypothesis that medial SMC loss occurs by apoptotic death and is driven by CD8+ T lymphocytes.

Prolongation of allograft survival by Nippostrongylus brasiliensis is associated with decreased allospecific cytotoxic T lymphocyte activity and development of T cytotoxic cell type 2 cells

BACKGROUND

We have demonstrated that infection with Nippostrongylus brasiliensis (Nb), which induces strong type 2 responses, prolongs kidney allograft survival in rats. Here, we confirm that this effect is not species-specific and address immune modulation in allospecific T-cell responses mediated by nematode infection.

METHODS

C57BL/6 mice were injected with Nb or phosphate-buffered saline. Four days later, mice were transplanted with BALB/c hearts and graft survival was assessed. In other experiments, Nb-infected mice were immunized with BALB/c spleen cells and allospecific T-cell responses were determined in vitro.

RESULTS

In this study, we show that Nb prolongs cardiac allograft survival in mice. Further, spleen T cells from Nb-infected, allo-immunized mice exhibit reduced allospecific cytotoxic T-lymphocyte activity. In contrast, allospecific proliferation of T cells in the mixed lymphocyte reaction was not reduced by Nb, ruling out immunosuppression as the mechanism of Nb-induced allograft survival. Nb infection induced IL-4 and IL-6 and inhibited IFN-gamma production by T cells in response to allo-antigen. Furthermore, anti-IL-4 treatment reduced allospecific T-cell proliferation from Nb-infected but not control mice, indicating that type 2 allospecific T cells develop in the presence of Nb. We also double-stained T cells for CD8 and IL-4 and showed that Nb induces an 8-fold increase in Tc2 cell numbers.

CONCLUSIONS

These results are consistent with a hypothesis that Nb mediates prolongation of allograft survival through induction of type 2 immunity, including the development of regulatory Tc2 cells, and subsequent inhibition of allospecific cytotoxic T-lymphocyte activity.

Method for screening peptide fragment ion mass spectra prior to database searching

A methodology is described for screening fragment ion spectra of peptides prior to database searching for protein identification. A software routine written in the Perl programming language was used to analyze data from previous Sequest database searches and develop a set of statistical descriptors that could be used to identify spectra not likely to yield useful results in a database search. A second Perl program used an evolutionary algorithm to optimize the criteria for each statistical descriptor and generate a formula for determining spectral quality. This formula was used by a third Perl program to screen data sets from four independent liquid chromatography tandem mass spectrometry runs. On the average, use of the screening program reduced the time required for a database search by 1/2 with little loss of useful information from the database search results.

Effects of aging on automatic and effortful processes in bimanual coordination

Two experiments are reported that compared younger and older adults on their performance of two bimanual temporal coordination tasks at varying movement speeds. In many cases, older adults performed as well as younger adults at all speeds of an in-phase coordination pattern and at slow speeds of an anti-phase pattern for both coordination accuracy and stability. Age differences tended to emerge most prominently at high speeds for the anti-phase pattern. These findings are consistent with the aging literature regarding automatic and effortful processing distinctions, suggesting that relative age differences become magnified when effortful resources are required for motor performance.

A micromachined chip-based electrospray source for mass spectrometry

A micromachining process is described for fabricating a mass spectrometry electrospray source on a silicon chip. The process utilizes polymer (parylene) layers to form a system of chambers, filters, channels, and hollow needle structures (electrospray emitters) that extend more than a millimeter beyond the edge of the silicon substrate. The use of photoresist as the sacrificial layer facilitates the creation of long channels. Access to the channel structures on the chip is through a port etched through the silicon substrate that also serves as a sample reservoir. A reusable chip holder consisting of two plastic plates and an elastomer gasket provides the means to mount the chip in front of the mass spectrometer inlet and make electrical and gas connections. The electrospray emitters have tapered tips with 5 microns x 10 microns rectangular openings. The shape of the tip can be varied depending on the shape of the mask used to protect the parylene structures during the final plasma etch. The parylene emitters are physically robust and require only a high electric field to achieve stable electrospray operation over a period of a few hours. Direct comparisons with conventional glass or fused silica emitters indicated very similar performance with respect to signal strength and stability, spectral quality, and endurance. The automated MS/MS analysis of a mixture of tryptic peptides was no more difficult and yielded nearly identical results as the analysis of the same sample using a conventional nanospray device. This work demonstrates that an efficient electrospray interface to mass spectrometry can be integrated with other on-chip structures and mass-produced using a batch process.

Oligosaccharide profiling: the facile detection of mono-, di- and oligosaccharides by electrospray orthogonal time-of-flight mass spectrometry using 3-aminophenylboronic acid derivatization

Monosaccharides, disaccharides and larger carbohydrates can be derivatized using 3-aminophenylboronic acid (3-APBA). This procedure is carried out at low pH (2.7-3.0) and allows the use of positive ion mode electrospray orthogonal time-of-flight mass spectrometry (ES-OTOFMS) to analyze the resulting boronate complexes. A carbohydrate profile map of a complex carbohydrate mixture, honey, was prepared which displayed superior sensitivity when compared with lithium ion cationization. Complexes formed using simple mono- and disaccharides show that facile in situ derivatization leads to an equilibrium mixture; which is reproducible for a specific set of electrospray conditions. D-Glucose could be detected at 5 microM concentration using the standard instrument spray interface. Lower detection levels of approximately 500 nM could be achieved using a nanospray device. The 3-APBA complexes are observed on instruments employing a low temperature interface (140-150 degrees C) which allows formation of the boronate species while still promoting efficient desolvation of the ions. The spectral identification of 3-APBA complexed carbohydrates in complex mixtures is facilitated by the easily observed 1 mass unit separated peak pair bearing the 1:4 ratio resulting from the natural isotopic abundance of (10)B and (11)B.

Nematode infection enhances survival of activated T cells by modulating accessory cell function

The type of immune response generated following exposure to Ag depends on a variety of factors, including the nature of the Ag, the type of adjuvant used, the site of antigenic entry, and the immune status of the host. We have previously shown that infection of rodents with Nippostrongylus brasiliensis (Nb) shifts the development of type 1 allo-specific responses toward type 2 immunity, suggesting nematode modulation of T cell activation. In this report we explore the immunomodulatory effects of Nb on T cell activation. We found that spleen cells from Nb-infected mice exhibited dramatically increased proliferation in response to Con A and anti-CD3. This hyperproliferation could be transferred in vitro to naive splenocytes by coculture with mitomycin C-treated cells from Nb-infected animals. The transfer was mediated by non-T accessory cells and supernatants derived from Con A-activated non-T cells, suggesting the involvement of a soluble factor secreted by accessory cells. The accessory cells secreted high levels of IL-6, and anti-IL-6 treatment abrogated the supernatant-induced hyperproliferation, thus confirming that IL-6 was mediating the effect. Further, spleen cells from Nb-infected mice were more resistant to activation-induced cell death (AICD) following mitogenic stimulation. Reduced AICD was also transferable and IL-6 dependent. Thus, the hyperproliferation was in part due to enhanced activated T cell survival. These phenomena mediated by accessory cells may contribute to the powerful polyclonal activation of type 2 immunity caused by nematode infection.

Heterogeneity of HLA-DR2 haplotypes in Caucasoid Americans, African Americans, Chinese Americans, Native Americans and Xiamen Chinese

HLA-DR, -DQ specificities were determined by PCR amplification with SSOP in 4560 individuals: Caucasoid Americans (CA), African Americans (AA), Chinese Americans (ChA), Native Americans (NA) and Xiamen Chinese (XC). DR2 subtypes were compared amongst the five ethnic populations. The DRB1*1501-DRB5*0101 haplotype was found to be the most frequent in all populations except African Americans, in which DRB1*1503-DRB5*0101 was the predominant haplotype, accounting for 65% of DR2 subtypes. In contrast to Caucasoid Americans, the DRB1*1602 is strongly associated with the DRB5*0101 allele in Chinese populations. The presence of DRB5*0203 and DRB1*1602-DRB5*0101 haplotypes in Chinese populations, especially in Xiamen Chinese, suggests that various DR2 haplotypes may be generated via multiple gene conversion events together with point mutations and reciprocal recombination. The strong DR and DQ associations are found in DRB1*1501/DQB1*0602 (66.22%) for CA, DRB1*1503/DQB1*0602 (56.58%) for AA, DRB1*1501/DQB1*0602 (30.20%) and DRB1*1602/DQB1*0502 (15.76%) for ChA, DRB1* 1501/DQB1*0602 (41.55%) and DRB1*1602/DQB1*0301 (40.25%) for NA, and DRB1*1501/DQB1*0602 (30.26%) and DRB1*1602/DQB1*0502 (25.81%) for XC.

COOH-terminally extended secretins are potent stimulants of pancreatic secretion

Posttranslational processing of preprosecretin generates several COOH-terminally extended forms of secretin and alpha-carboxyl amidated secretin. We used synthetic canine secretin analogs with COOH-terminal -amide, -Gly, or -Gly-Lys-Arg to examine the effects of COOH-terminal extensions of secretin on bioactivity and detection in RIA. Synthetic products were purified by reverse-phase and ion-exchange HPLC and characterized by reverse-phase isocratic HPLC and amino acid, sequence, and mass spectral analyses. Secretin and secretin-Gly were noted to coelute during reverse-phase HPLC. In RIA using eight different antisera raised against amidated secretin, COOH-terminally extended secretins had little or no cross-reactivity. Bioactivity was assessed by measuring pancreatic responses in anesthetized rats. Amidated canine and porcine secretins were equipotent. Secretin-Gly and secretin-Gly-Lys-Arg had potencies of 81 +/- 9% (P > 0.05) and 176 +/- 13% (P < 0.01), respectively, compared with amidated secretin, and the response to secretin-Gly-Lys-Arg lasted significantly longer. These data demonstrate that 1) amidated secretin and secretin-Gly are not separable under some chromatographic conditions, 2) current RIA may not detect bioactive COOH-terminally extended forms of secretin in tissue extracts or blood, and 3) the secretin receptor mediating stimulation of pancreatic secretion recognizes both amidated and COOH-terminally extended secretins.

Marrow donor registry and bone marrow transplantation from unrelated donors in Taiwan: initial experience of the Tzu Chi Taiwan Marrow Donor Registry (TCTMDR)

To evaluate the outcomes of unrelated bone marrow transplantation facilitated by TCTMDR, we focused on 48 marrow transplants performed in Taiwan during the period May 1994 to June 1997. Follow-up of these 48 cases was made up to 30 May 1998. The average length of follow-up was 328 days (range 7-1385 days). All the donor/recipient pairs were HLA-A, B and DR matched and were divided into two risk groups based on diagnosis and stage of disease. There were 24 standard risk and 24 high risk patients. Engraftment occurred in 40 patients (83.3%). Acute and chronic GVHD was observed in 80% of evaluable patients and accounts for 41% of deaths. The second leading cause of death was infection, accounting for 35% of deaths. The overall probability of survival for the 48 patients after BMT over 2 years was 33.3% (95% CI 19.67-46.32%). The probability of survival for standard risk and high risk groups was 54% and 8%, respectively. In multivariate analysis, patients who were younger, in the standard risk group, or with a shorter search interval showed a higher survival probability.

Distribution of HLA gene and haplotype frequencies in Taiwan: a comparative study among Min-nan, Hakka, Aborigines and Mainland Chinese

A total of 8,497 blood samples were typed for HLA-A, B, DR and DQ. Of these, 7,137 Min-nan, 714 Hakka, 535 Mainland Chinese (152 from North China, 211 from Middle China, and 172 from South China) and 111 Aborigines were randomly selected from Tzu Chi Taiwan Marrow Donor Registry (TCTMDR). Differences in HLA gene and antigen frequencies have been observed between various ethnic groups of the Chinese population in Taiwan. The phylogenic tree shows Taiwan Aborigines and Javanese cluster together; Min-nan shares a common cluster with Hakka, Southern Hans and Thai; and Northern Hans shares a cluster with Middle Hans. The separation between Northern/Middle and Southern Chinese Hans support the idea that Northern and Southern Chinese have different genetic background. Aborigines appeared to be quite distinct in the distribution of a majority of the class I and class II antigens. High frequency of HLA-A24 (60.4%) and relatively restricted HLA polymorphisms are noted in Aborigines. The HLA haplotypes with high frequency in Aborigines included A24-B60-DRB1*04, A24-B60-DRB1*14, A24-B48-DRB1*04, and A24-B48-DRB1*14, which are different from the other ethnic groups. Although the phylogenic tree separates Aborigines and Han Chinese populations, 4 out of 20 most common HLA-A, -B, and -DR haplotypes presented in both Aborigines and Han Chinese may reflect an ancient common origin or intermixture between early settlers of Han Chinese and Taiwan Aborigines. The results in this study are essentially a summary of the observed gene/haplotype frequencies and differences among various ethnic groups in Taiwan.

Liquid chromatography/microspray mass spectrometry for bacterial investigations

Cellular proteins (biomarkers) specific to any individual microorganism, determined by the direct mass spectral analysis of the corresponding intact cellular suspension, can be applied for the rapid and specific identification of the organisms present in unknown samples. The components of the bacterial suspensions, after a rapid separation over a C18 reversed-phase microcapillary column, were directly subjected to on-line electrospray ionization followed by analysis using an ion trap tandem mass spectrometer. This approach is equally effective for gram-positive as well as gram-negative bacteria but has a distinct advantage over our earlier reported method involving matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). During electrospray ionitation mass spectrometry (ESI-MS), liquid samples can be directly analyzed and there is the potential for developing tandem mass spectral methods for more specific identification of the individual organisms present in crude bacterial mixtures. The total analysis time leading to unambiguous bacterial identification in samples was less than 10 minutes and the results were quite reproducible. Miniaturization of the instrumentation along with total automation of this simple process could have immense impact on field operations. Routine, rapid, cost-effective field monitoring of environmental samples, agricultural products, samples from food processing, industrial sites and health institutions for suspected bacterial contamination could be a reality in the near future. Potential utility in biological, medical, bioprocessing, pharmaceutical, and other industrial research is also enormous.

On the dynamics of motor learning research

In this paper I have attempted to conceptualize the dynamical pattern view of learning (Zanone & Kelso, 1992, 1994, 1997) in terms of some historical similarities to the dynamic pattern perspective, unique contributions, and potential problems to be addressed in future research and theory. For researchers interested in motor learning issues, all three of these points can be viewed only as positive advances to the field of study.

A microscale electrospray interface incorporating a monolithic, poly(styrene-divinylbenzene) support for on-line liquid chromatography/tandem mass spectrometry analysis of peptides and proteins

A methodology is described for creating a monolithic chromatography support within a pulled fused-silica electrospray needle. The monolith was formed from a mixture of styrene, divinylbenzene, 1-dodecanol, and toluene using 2,2'-azobis(isobutyronitrile) as the catalyst. The mixture was loaded into 150-micron-i.d. fused-silica capillary tubing with a pulled 5-10-micron needle tip at one end. Polymerization at 65 degrees C followed by removal of the porogen material yielded a stable, porous, monolithic support which had excellent properties for the separation and on-line, electrospray, mass spectrometry analysis of peptides and proteins. The performance of the monolith-filled electrospray needles was compared with similar needles filled with commercial C18 silica and polymeric particulate supports. Separation efficiencies for both protein and peptide mixtures were generally equal to or better than the particulate supports at comparable pressures and flow rates. The ion chromatograms derived from the on-line MS analysis were remarkably free from chemical background signals that often complicate the LC/MS analysis of femtomole amounts of sample. Good sequence coverage was obtained by LC/MS/MS analysis of the peptide mixture obtained from a protein isolated by silver-stained gel electrophoresis. The capability of the monolith to do peak parking experiments was demonstrated by the characterization of an immunoreactive HPLC fraction. The simple fabrication method, chromatographic performance, and robust nature of these microscale integrated column electrospray sources make them ideally suited for high-sensitivity tandem LC/MS analyses.

Adhesion of tumoricidal eosinophils to MCA-38 colon adenocarcinoma cells involves protein tyrosine kinase activation and is diminished by elevated cyclic AMP in the effector cell

Although eosinophils have been implicated in immune responses to certain types of tumors, the mechanisms of anti-tumor activity by eosinophils are poorly understood. We show here that mouse eosinophils kill allogeneic MCA-38 colon adenocarcinoma cells in the absence of specific anti-body. Eosinophil adhesion to MCA-38 monolayers occurred within 15 min and plateaued at 90 min. Although mouse eosinophils express alphaL (CD11a), alphaM (CD11b), and alpha4 (CD49d) integrin chains, blocking antibody studies revealed that these molecules are not involved in eosinophil binding to MCA-38 cells. Adhesion was also fibronectin-independent. Binding was inhibited when eosinophils, but not MCA-38 cells, were pretreated with methyl 2,5-dihydroxycinnamate (MDHC), a selective inhibitor of protein tyrosine kinases, or 8-Br-cAMP-Na, a cell-permeable cyclic AMP analogue. Adhesion was unaffected by calphostin C, a specific inhibitor of protein kinase C, and wortmannin, a selective inhibitor of phosphatidylinositol 3-kinases.

Prolongation of survival of primary renal allografts by feeding of donor spleen cells

We have found that feeding Brown Norway (BN) rat spleen cells to Lewis rats prior to transplanting BN kidneys prolongs allograft survival (mean: 8.8 days in unfed rats, 21 days in the BN cell-fed rats; longest survival: 11 days without allo-feeding vs. 37 days with feeding). We have also found that feeding BN cells both before and after transplantation further extends survival (mean: 38 days; longest survival: 105 days). We also examined the cells infiltrating the grafts during the early stages of the allograft response (day 5). Using flow cytometry, we found a significant decrease in the number of leukocytes infiltrating the transplanted kidneys of fed animals. This decrease was mainly due to a drop in the number of infiltrating T cells. We also found that cytokine mRNA production by the graft-infiltrating lymphocytes, assessed by reverse transcription polymerase chain reaction, showed a significant increase in interleukin-4 and transforming-growth factor-beta mRNA in the graft-infiltrating lymphocytes of fed animals compared with the controls.