T cell interleukin-17 induces stromal cells to produce proinflammatory and hematopoietic cytokines

Analysis of the cDNA encoding murine interleukin (IL) 17 (cytotoxic T lymphocyte associated antigen 8) predicted a secreted protein sharing 57% amino acid identity with the protein predicted from ORF13, an open reading frame of Herpesvirus saimiri. Here we report on the cloning of human IL-17 (hIL-17), the human counterpart of murine IL-17. hIL-17 is a glycoprotein of 155 amino acids secreted as an homodimer by activated memory CD4+ T cells. Although devoid of direct effects on cells of hematopoietic origin, hIL-17 and the product of its viral counterpart, ORF13, stimulate epithelial, endothelial, and fibroblastic cells to secrete cytokines such as IL-6, IL-8, and granulocyte-colony-stimulating factor, as well as prostaglandin E2. Furthermore, when cultured in the presence of hIL-17, fibroblasts could sustain the proliferation of CD34+ hematopoietic progenitors and their preferential maturation into neutrophils. These observations suggest that hIL-17 may constitute (a) an early initiator of the T cell-dependent inflammmatory reaction; and (b) an element of the cytokine network that bridges the immune system to hematopoiesis.

Interleukin 10 is a potent growth and differentiation factor for activated human B lymphocytes

Interleukin 10 (IL-10), originally identified as a TH2 helper T-cell product able to inhibit cytokine production by TH1 cells, is highly homologous to BCRF1 (viral IL-10), an open reading frame in the Epstein-Barr virus genome. Here, we show that human and viral IL-10 stimulate DNA replication of B lymphocytes activated either via their antigen receptor or via their CD40 antigen. IL-4 and IL-10 display additive effects and induce a strong increase in the number of viable cells. Moreover, IL-10 induces activated B cells to secrete large amounts of IgG, IgA, and IgM, and the combination of IL-10 and IL-4 results in the secretion of the four immunoglobulin isotypes. Thus, IL-10 may play an important role in the amplification of humoral responses.

Coronary angioplasty with or without stent implantation for acute myocardial infarction. Stent Primary Angioplasty in Myocardial Infarction Study Group

BACKGROUND

Coronary-stent implantation is frequently performed for treatment of acute myocardial infarction. However, few studies have compared stent implantation with primary angioplasty alone.

METHODS

We designed a multicenter study to compare primary angioplasty with angioplasty accompanied by implantation of a heparin-coated Palmaz-Schatz stent. Patients with acute myocardial infarction underwent emergency catheterization and angioplasty. Those with vessels suitable for stenting were randomly assigned to undergo angioplasty with stenting (452 patients) or angioplasty alone (448 patients).

RESULTS

The mean (+/-SD) minimal luminal diameter was larger after stenting than after angioplasty alone (2.56+/-0.44 mm vs. 2.12+/-0.45 mm, P<0.001), although fewer patients assigned to stenting had grade 3 blood flow (according to the classification of the Thrombolysis in Myocardial Infarction trial) (89.4 percent, vs. 92.7 percent in the angioplasty group; P=0.10). After six months, fewer patients in the stent group than in the angioplasty group had angina (11.3 percent vs. 16.9 percent, P=0.02) or needed target-vessel revascularization because of ischemia (7.7 percent vs. 17.0 percent, P<0.001). In addition, the combined primary end point of death, reinfarction, disabling stroke, or target-vessel revascularization because of ischemia occurred in fewer patients in the stent group than in the angioplasty group (12.6 percent vs. 20.1 percent, P<0.01). The decrease in the combined end point was due entirely to the decreased need for target-vessel revascularization. The six-month mortality rates were 4.2 percent in the stent group and 2.7 percent in the angioplasty group (P=0.27). Angiographic follow-up at 6.5 months demonstrated a lower incidence of restenosis in the stent group than in the angioplasty group (20.3 percent vs. 33.5 percent, P<0.001).

CONCLUSIONS

In patients with acute myocardial infarction, routine implantation of a stent has clinical benefits beyond those of primary coronary angioplasty alone.

Insights into the evolution of Yersinia pestis through whole-genome comparison with Yersinia pseudotuberculosis

Yersinia pestis, the causative agent of plague, is a highly uniform clone that diverged recently from the enteric pathogen Yersinia pseudotuberculosis. Despite their close genetic relationship, they differ radically in their pathogenicity and transmission. Here, we report the complete genomic sequence of Y. pseudotuberculosis IP32953 and its use for detailed genome comparisons with available Y. pestis sequences. Analyses of identified differences across a panel of Yersinia isolates from around the world reveal 32 Y. pestis chromosomal genes that, together with the two Y. pestis-specific plasmids, to our knowledge, represent the only new genetic material in Y. pestis acquired since the the divergence from Y. pseudotuberculosis. In contrast, 149 other pseudogenes (doubling the previous estimate) and 317 genes absent from Y. pestis were detected, indicating that as many as 13% of Y. pseudotuberculosis genes no longer function in Y. pestis. Extensive insertion sequence-mediated genome rearrangements and reductive evolution through massive gene loss, resulting in elimination and modification of preexisting gene expression pathways, appear to be more important than acquisition of genes in the evolution of Y. pestis. These results provide a sobering example of how a highly virulent epidemic clone can suddenly emerge from a less virulent, closely related progenitor.

Randomised comparison of implantation of heparin-coated stents with balloon angioplasty in selected patients with coronary artery disease (Benestent II)

BACKGROUND

The multicentre, randomised Benestent-II study investigated a strategy of implantation of a heparin-coated Palmar-Schatz stent plus antiplatelet drugs compared with the use of balloon angioplasty in selected patients with stable or stabilised unstable angina, with one or more de-novo lesions, less than 18 mm long, in vessels of diameter 3 mm or more.

METHODS

827 patients were randomly assigned stent implantation (414 patients) or standard balloon angioplasty (413 patients). The primary clinical endpoint was event-free survival at 6 months, including death, myocardial infarction, and the need for revascularisation. The secondary endpoints were the restenosis rate at 6 months and the cost-effectiveness at 12 months. There was also one-to-one subrandomisation to either clinical and angiographic follow-up or clinical follow-up alone. Analyses were by intention to treat.

FINDINGS

Four patients (one stent group, three angioplasty group) were excluded from analysis since no lesion was found. At 6 months, a primary clinical endpoint had occurred in 53 (12.8%) of 413 patients in the stent group and 79 (19.3%) of 410 in the angioplasty group (p=0.013). This significant difference in clinical outcome was maintained at 12 months. In the subgroup assigned angiographic follow-up, the mean minimum lumen diameter was greater in the stent group than in the balloon-angioplasty group, (1.89 [SD 0.65] vs 1.66 [0.57] mm, p=0.0002), which corresponds to restenosis rates (diameter stenosis > or =50%) of 16% and 31% (p=0.0008). In the group assigned clinical follow-up alone, event-free survival rate at 12 months was higher in the stent group than the balloon-angioplasty group (0.89 vs 0.79, p=0.004) at a cost of an additional 2085 Dutch guilders (US$1020) per patient.

INTERPRETATION

Over 12-month follow-up, a strategy of elective stenting with heparin-coated stents is more effective but also more costly than balloon angioplasty.

Long-term human B cell lines dependent on interleukin-4 and antibody to CD40

CD40 is a 45- to 50-kilodalton transmembrane glycoprotein expressed on B lymphocytes, epithelial cells, and some carcinoma cell lines. Human resting B lymphocytes entered a state of sustained proliferation when incubated with both the mouse fibroblastic Ltk- cell line that had been transfected with the human Fc receptor (Fc gamma RII/CDw32) and monoclonal antibodies to CD40. In combination with interleukin-4, factor-dependent long-term normal human B cell lines were generated that were consistently negative for Epstein-Barr viral infection. Thus, cross-linking of CD40 is likely to represent an important phenomenon in the clonal expansion of B cells.

Normal flow (TIMI-3) before mechanical reperfusion therapy is an independent determinant of survival in acute myocardial infarction: analysis from the primary angioplasty in myocardial infarction trials

BACKGROUND

Whereas survival after lytic therapy for myocardial infarction is strongly dependent on early administration, it is unknown whether the otherwise excellent outcomes in patients undergoing primary PTCA for acute myocardial infarction, in whom TIMI-3 flow rates of >90% may be achieved, can be further improved by early reperfusion.

METHODS AND RESULTS

Among 2507 patients enrolled in 4 PAMI trials undergoing primary PTCA, spontaneous reperfusion (TIMI-3 flow) was present in 16% at initial angiography. Compared with patients without TIMI-3 flow, those with TIMI-3 flow before PTCA had greater left ventricular ejection fraction (57+/-10% versus 53+/-11%, P=0.003) and were less likely to present in heart failure (7.0% versus 11.6%, P=0.009). Patients with initial TIMI-3 flow had significantly lower in-hospital rates of mortality, new-onset heart failure, and hypotension and had a shorter hospital stay. Cumulative 6-month mortality was 0.5% in patients with initial TIMI-3 flow, 2.8% with TIMI-2 flow, and 4.4% with initial TIMI-0/1 flow (P=0.009). By multivariate analysis, TIMI-3 flow before PTCA was an independent determinant of survival (odds ratio 2.1, P=0.04), even when corrected for by postprocedural TIMI-3 flow.

CONCLUSIONS

Patients undergoing primary PTCA in whom TIMI-3 flow is present before angioplasty present with greater clinical and angiographic evidence of myocardial salvage, are less likely to develop complications related to left ventricular failure, and have improved early and late survival. These data warrant prospective randomized trials of pharmacological strategies to promote early reperfusion before definitive mechanical intervention in acute myocardial infarction.

Fas ligation induces apoptosis of CD40-activated human B lymphocytes

Since CD40/CD40 ligand (CD40Lig) interactions are essential in vivo for the generation of germinal center B cells that express Fas (Apo-1/CD95), we explored whether CD40 engagement may modulate Fas expression and function on human B lymphocytes. Resting tonsil B cells, isolated by density gradient centrifugation, express either absent or low levels of Fas. They could be induced to promptly express Fas after ligation of their CD40, however, using either a recombinant human CD40Lig or a cross-linked anti-CD40 mAb. In contrast, engagement of the B cell antigen receptor by immobilized anti-kappa and -lambda antibodies did not turn on Fas expression. Addition of anti-Fas mAb CH11 inhibited the later phases of CD40-induced B cell growth as a result of apoptotic cell death. Furthermore, Fas ligation inhibited proliferation and Ig secretion of CD40-activated B cells in response to recombinant cytokines such as interleukin (IL)-2, IL-4, and IL-10, as well as a cytokine-rich supernatant of phytohemagglutinin-activated T cells, indicating that none of those B cell tropic factors were able to prevent the Fas-induced death. Taken together, the present results show that engagement of CD40 antigen on B cells induces Fas expression and sensitizes them to Fas-mediated apoptosis. The delayed functional response to Fas ligation after CD40 activation may represent a way to limit the size of a specific B cell clone that is generated during T-B cell interactions.

Cytokine-induced proliferation and immunoglobulin production of human B lymphocytes triggered through their CD40 antigen

Human resting B lymphocytes enter a state of sustained proliferation when incubated with both mouse fibroblastic L cells stably expressing Fc gamma RII/CDw32 and anti-CD40 antibodies. We have explored the effects of 11 recombinant human cytokines (CKs) on induced cell proliferation and immunoglobulin (Ig) production. Interleukin 4 (IL-4) was the only CK able to enhance anti-CD40-induced B cell multiplication as measured by enumeration of viable cells, and interferon gamma (IFN-gamma) further stimulated this induced proliferation. IL-4 enhanced the production of IgM and IgG by B cells and induced them to produce IgE. Combinations of IL-4 and IL-2 resulted in the production of large amounts of IgM and IgA. Interestingly, IFN-gamma did not inhibit the production of IgE by cells stimulated with anti-CD40 and IL-4. None of the tested CK combinations resulted in the production of large quantities of IgG. Therefore, this new culture system represents a unique model to study isotype regulation in highly purified human B lymphocytes, in addition to allowing the generation of long-term factor-dependent human B cell lines.

Heparin-coated Palmaz-Schatz stents in human coronary arteries. Early outcome of the Benestent-II Pilot Study

BACKGROUND

The purpose of the Benestent-II Pilot Study was to evaluate the safety of delaying and eliminating anticoagulant therapy in patients receiving a heparin-coated stent in conjunction with antiplatelet drugs.

METHODS AND RESULTS

The study consisted of three initial phases (I, II, III) during which resumption of heparin therapy after sheath removal was progressively deferred by 6, 12, and 36 hours. In phase IV, coumadin and heparin were replaced by 250 mg ticlopidine and 100 mg aspirin. Of the 207 patients with stable angina pectoris and a de novo lesion in whom heparin-coated stent implantation was attempted, implantation was successful in 202 patients (98%). Stent thrombosis did not occur during all four phases, and the overall clinical success rate at discharge was 99%. Bleeding complications requiring blood transfusion or surgery fell from 7.9% in phase I to 5.9%, 4%, and 0% in the three following phases. Hospital stay was 7.4, 6.1, 7.2, and 3.1 days for the consecutive phases. The restenosis rate for the combined four phases was 13% (15% in phase I, 20% in phase II, 11% in phase III, and 6% in phase IV). The overall rate of reintervention for the four phases was 8.9%. At 6 months, 84%, 75%, 94%, and 92% of the patients of phases I to IV, respectively, were event free. For the four phases, the event-free rate was 86%, which compares favorably with the rate observed in the Benestent-I study (80%; relative risk, 0.68 [0.45 to 1.04]).

CONCLUSIONS

The implantation of stents coated with polyamine and end-point-attached heparin in stable patients with one significant de novo coronary lesion is well tolerated, is associated with no (sub)acute stent thrombosis, and results in a favorable event-free survival after 6 months.

Puromycin-based purification of rat brain capillary endothelial cell cultures. Effect on the expression of blood-brain barrier-specific properties

One of the main difficulties with primary rat brain endothelial cell (RBEC) cultures is obtaining pure cultures. The variation in purity limits the achievement of in vitro models of the rat blood-brain barrier. As P-glycoprotein expression is known to be much higher in RBECs than in any contaminating cells, we have tested the effect of five P-glycoprotein substrates (vincristine, vinblastine, colchicine, puromycin and doxorubicin) on RBEC cultures, assuming that RBECs would resist the treatment with these toxic compounds whereas contaminating cells would not. Treatment with either 4 microg/mL puromycin for the first 2 days of culture or 3 microg/mL puromycin for the first 3 days showed the best results without causing toxicity to the cells. Transendothelial electrical resistance was significantly increased in cell monolayers treated with puromycin compared with untreated cell monolayers. When cocultured with astrocytes in the presence of cAMP, the puromycin-treated RBEC monolayer showed a highly reduced permeability to sodium fluorescein (down to 0.75 x 10(-6) cm/s) and a high electrical resistance (up to 500 Omega x cm(2)). In conclusion, this method of RBEC purification will allow the production of in vitro models of the rat blood-brain barrier for cellular and molecular biology studies as well as pharmacological investigations.

Clinical characteristics and outcome of patients with early (<2 h), intermediate (2-4 h) and late (>4 h) presentation treated by primary coronary angioplasty or thrombolytic therapy for acute myocardial infarction

AIMS

We examined the clinical characteristics and outcome of patients with early (<2 h), intermediate (2-4 h) and late (>4 h) presentation treated by primary angioplasty or thrombolytic therapy for acute myocardial infarction.

METHODS AND RESULTS

We studied 2635 patients enrolled in 10 randomized trials of primary angioplasty (n=1302) vs thrombolytic therapy (n=1333) in acute myocardial infarction, and baseline characteristics of the two groups were comparable. Increase in presentation delay is associated with older age, female gender, diabetes and an increased heart rate. We classified the patients according to the time delay from symptom onset to presentation into three categories: early presentation (<2 h), intermediate presentation (2-4 h), and late presentation (>or=4 h). At 30 days the combined rate of death, non-fatal reinfarction and stroke in patients presenting early was 5.8% in the angioplasty group vs 12.5% in the thrombolysis group, in patients with intermediate presentation, 8.6% vs 14.2%, respectively, and in patients presenting late 7.7% vs 19.4%, respectively. With increasing time from symptom onset to presentation, all major adverse cardiac event rates show a trend to a larger increase in the thrombolysis group compared to the angioplasty group, both at 30 days and at 6 months after the acute event.

CONCLUSIONS

Major adverse cardiac event rates are lower after angioplasty compared to thrombolysis, irrespective of time to presentation. With increasing time to presentation major adverse cardiac event rates increase after thrombolysis but appear to remain relatively stable after angioplasty.

Use of immunocytochemistry of progesterone and estrogen receptors for endometrial dating

Endometrial progesterone and estrogen receptors were studied by immunocytochemistry using monoclonal antibodies during the menstrual cycle in normal women. We initially compared immunocytochemical staining of progesterone and estradiol receptors on endometrial fragments obtained by either aspiration or endometrial biopsy and found that immunocytochemistry could be performed easily on tissue obtained in either way. The immunocytochemical studies showed that the concentration and distribution of receptors changed markedly during the normal menstrual cycle. These changes were distributed in three characteristic phases. During phase I, corresponding to the midfollicular period (days 7-8), a small proportion (25%) of stromal and glandular cells stained positively for the progesterone receptor, whereas estrogen receptor staining was more intense and more frequent (50% of cells). Phase II, which included both the late follicular and early luteal periods (days 9-19), was characterized by a marked staining of progesterone receptors in the majority of glandular cells (75%) and somewhat less abundant and less frequent staining in stromal cells (50%). Estrogen receptor staining was present in about half of the glandular and stromal cells. Phase III, the mid- and late luteal period (days 21-27), was characterized by the disappearance of estrogen and progesterone receptor staining in glandular cells, although faint staining for both receptors was found in stromal cells. These variations in progesterone receptor staining are potentially useful for determining the effect of progesterone on endometrial maturation.

Horizontal gene transfer of the Escherichia coli pap and prs pili operons as a mechanism for the development of tissue-specific adhesive properties

Escherichia coli strains bind to Gal alpha 1-4Gal-containing glycolipids via P pili-associated G-adhesins. Three functional classes of adhesins with different binding specificities are encoded by conserved G-alleles. We suggest that the Class I papG-allele of strain J96 is a novel acquisition possibly introduced via horizontal gene transfer into one of the two P pili gene clusters carried by this strain. Closely related strains in the ECOR collection of natural E. coli isolates carry either a Class II or a Class III G-adhesin. Data indicate that genetic exchanges involving either entire pap or prs gene clusters or individual pap/prs genes have occurred. We propose that the retention and spread of pap/prs DNA among E. coli is the result of selection pressure exerted by mammalian intestinal isoreceptors.

The transient receptor potential channel antagonist SKF96365 is a potent blocker of low-voltage-activated T-type calcium channels

BACKGROUND AND PURPOSE

SKF96365 (SKF), originally identified as a blocker of receptor-mediated calcium entry, is widely used diagnostically, as a blocker of transient receptor potential canonical type (TRPC) channels. While SKF has been used as a tool to define the functional roles of TRPC channels in various cell and tissue types, there are notable overlapping physiological and pathophysiological associations between TRPC channels and low-voltage-activated (LVA) T-type calcium channels. The activity of SKF against T-type Ca channels has not been previously explored, and here we systematically investigated the effects of SKF on recombinant and native voltage-gated Ca channel-mediated currents.

EXPERIMENTAL APPROACH

Effects of SKF on recombinant Ca channels were studied under whole-cell patch clamp conditions after expression in HEK293 cells. The effect of SKF on cerebellar Purkinje cells (PCs) expressing native T-type Ca channels was also assessed.

KEY RESULTS

SKF blocked recombinant Ca channels, representative of each of the three main molecular genetic classes (Ca(V)1, Ca(V)2 and Ca(V)3) at concentrations typically utilized to assay TRPC function (10 microM). Particularly, human Ca(V)3.1 T-type Ca channels were more potently inhibited by SKF (IC(50) approximately 560 nM) in our experiments than previously reported for similarly expressed TRPC channels. SKF also inhibited native Ca(V)3.1 T-type currents in a rat cerebellar PC slice preparation.

CONCLUSIONS AND IMPLICATIONS

SKF was a potent blocker of LVA T-type Ca channels. We suggest caution in the interpretation of results using SKF alone as a diagnostic agent for TRPC activity in native tissues.

An integrated metric physical map of human chromosome 19

A metric physical map of human chromosome 19 has been generated. The foundation of the map is sets of overlapping cosmids (contigs) generated by automated fingerprinting spanning over 95% of the euchromatin, about 50 megabases (Mb). Distances between selected cosmid clones were estimated using fluorescence in situ hybridization in sperm pronuclei, providing both order and distance between contigs. An average inter-marker separation of 230 kb has been obtained across the non-centromeric portion of the chromosome. Various types of larger insert clones were used to span gaps between contigs. Currently, the map consists of 51 'islands' containing multiple clone types, whose size, order and relative distance are known. Over 450 genes, genetic markers, sequence tagged sites (STSs), anonymous cDNAs, and other markers have been localized. In addition, EcoRI restriction maps have been generated for > 41 Mb (approximately 83%) of the chromosome.

Structural organization of virulence-associated plasmids of Yersinia pestis

The complete nucleotide sequence and gene organization of the three virulence plasmids from Yersinia pestis KIM5 were determined. Plasmid pPCP1 (9,610 bp) has a GC content of 45.3% and encodes two previously known virulence factors, an associated protein, and a single copy of IS100. Plasmid pCD1 (70,504 bp) has a GC content of 44.8%. It is known to encode a number of essential virulence determinants, regulatory functions, and a multiprotein secretory system comprising the low-calcium response stimulation that is shared with the other two Yersinia species pathogenic for humans (Y. pseudotuberculosis and Y. enterocolitica). A new pseudogene, which occurs as an intact gene in the Y. enterocolitica and Y. pseudotuberculosis-derived analogues, was found in pCD1. It corresponds to that encoding the lipoprotein YlpA. Several intact and partial insertion sequences and/or transposons were also found in pCD1, as well as six putative structural genes with high homology to proteins of unknown function in other yersiniae. The sequences of the genes involved in the replication of pCD1 are highly homologous to those of the cognate plasmids in Y. pseudotuberculosis and Y. enterocolitica, but their localization within the plasmid differs markedly from those of the latter. Plasmid pMT1 (100,984 bp) has a GC content of 50.2%. It possesses two copies of IS100, which are located 25 kb apart and in opposite orientations. Adjacent to one of these IS100 inserts is a partial copy of IS285. A single copy of an IS200-like element (recently named IS1541) was also located in pMT1. In addition to 5 previously described genes, such as murine toxin, capsule antigen, capsule anchoring protein, etc., 30 homologues to genes of several bacterial species were found in this plasmid, and another 44 open reading frames without homology to any known or hypothetical protein in the databases were predicted.

Searching for autolysin functions. Characterization of a pneumococcal mutant deleted in the lytA gene

The first mutant of Streptococcus pneumoniae showing a complete deletion in the lytA gene coding for the N-acetylmuramyl-L-alanine amidase has been isolated and characterized. This amidase was previously the only autolysin detected in this species. This mutant shows a normal growth rate and can be transformed using either chromosomal or plasmid DNA. The most remarkable biological consequences of the absence of the amidase are the formation of small chains (six to eight cells) and the absence of lysis in the stationary phase of growth. In addition, this mutant exhibits a tolerant response against the beta-lactam antibiotics.

Textural modification of processing tomatoes

Knowledge of the textural properties of processing tomatoes is crucial to ensuing product acceptability; measurement, control, and optimization of these properties through judicious selection of varieties and control of unit operations results in products that the consumer prefers. It is important to first define the terms texture, rheology, consistency, and viscosity prior to discussing principles of their measurement. The textural properties of processing tomatoes may be measured using both sensory and objective tests, and the latter may be either destructive or nondestructive in nature. The unique anatomy of tomato fruit (peel, pericarp, columella, and locules) in part dictates the method of texture measurement. Numerous factors, including variety, maturity, genetic modification, cultural particles, and environmental conditions, processing conditions, and calcium addition affect the textural integrity of tomatoes. Textural properties of raw tomatoes and most processed tomato products are reviewed in this article.

Angiographic and clinical characteristics associated with increased in-hospital mortality in elderly patients with acute myocardial infarction undergoing percutaneous intervention (a pooled analysis of the primary angioplasty in myocardial infarction trials)

Advanced age is associated with increased mortality in acute myocardial infarction (AMI) but the mechanism remains unclear. We performed a pooled analysis of 3,032 patients from the Primary Angioplasty in Myocardial Infarction (PAMI)-2, Stent-PAMI, and PAMI-No Surgery On Site trials to determine which clinical, hemodynamic, and angiographic characteristics in the elderly were associated with in-hospital death. There were 452 patients aged >/=75 years and 2,580 patients aged <75 years. Older patients had a lower number of risk factors for coronary artery disease but more comorbidities. Acute catheterization demonstrated more 3-vessel disease, higher left ventricular (LV) end-diastolic pressure, lower LV ejection fraction, and higher initial rates of Thrombolysis In Myocardial Infarction (TIMI) trial 2 or 3 flow. Elderly patients were equally likely to undergo percutaneous intervention but had a lower procedural success rate and lower rates of final TIMI 3 flow, and older patients were more likely to have post-AMI complications. In-hospital mortality was 10.2% and 1.8%, respectively (p = 0.001). Cardiac and noncardiac mortality was higher in elderly patients, and no significant differences in causes of death were identified. Multivariate analysis revealed that the strongest predictors of death were age >/=75 years, lower LV ejection fraction, lower final TIMI flow, higher Killip class, need for an intra-aortic balloon pump (IABP), and post-AMI stroke/transient ischemic attack, or significant arrhythmia. Despite avoiding thrombolysis, elderly patients remain at increased risk of bleeding, stroke, and other post-AMI complications, and death. Cardiac risk factor analysis and acute catheterization offer prognostic information but do not completely explain the mechanism of increased in-hospital mortality in the elderly.

Nitrogen control in Salmonella: regulation by the glnR and glnF gene products

The product of the glnR gene is required for nitrogen regulation of the synthesis of glutamine synthesis (Gln synthetase) [L-glutamate:ammonia ligase (ADP-forming), EC 6.3.1.2] and two periplasmic transport proteins that are subject to nitrogen control in Salmonella. Strains with mutations to loss of function of the glnR product [e.g., a strain with a Tn10 insertion or one with an ICR-induced (frameshift) mutation in glnR] have about 3% as much Gln synthetase as a fully derepressed wild-type strain and are unable to increase synthesis of this enzyme or periplasmic transport proteins in response to nitrogen limitation. The structural gene for Gln synthetase, glnA, and those for the periplasmic transport proteins are unlinked on the chromosome; thus, glnR appears to encode a diffusible positive regulatory element. Consistent with this, the mutant glnR allele is recessive to the wild-type allele with regard to expression of glnA (synthesis of Gln synthetase). Although glnR is closely linked to glnA, strains with mutations to complete loss of function of the glnR product can be distinguished from glnA strains by their ability to produce detectable Gln synthetase and to grow in the absence of glutamine. To demonstrate unequivocally that glnR is distinct from glnA, we have purified and characterized Gln synthetase from a strain with a Tn10 insertion in glnR. Because the properties of Gln synthetase from the insertion mutant, most importantly the carboxyl-terminal sequence of amino acids, are the same as those of synthetase from wild type, the Tn10 insertion cannot be in glnA (if it were, the carboxyl terminus of Gln synthetase would have to be altered); therefore we conclude that the Tn10 insertion is in a regulatory gene, glnR, which is distinct from glnA. A model for the function of the glnR product together with the previously defined glnF product in mediating nitrogen control is discussed.

Immunocytochemical demonstration of estrogen and progesterone receptors in muscle cells of uterine arteries in rabbits and humans

Modifications of uterine blood flow are implicated in many important aspects of reproductive physiology and in several of their pathological disorders. These modifications are hormonally regulated but remain poorly understood, and various complex mechanisms have been proposed. The aim of this study was to investigate the presence and some characteristics of estrogen receptors (ER) and progesterone receptors (PR) in uterine blood vessels. Using monoclonal antibodies and immunocytochemistry we observed the presence of ER and PR in muscle cells (tunica media) of uterine arteries of rabbits and women. ER or PR immunoreactivity was not detected in the endothelium of uterine arteries nor in uterine capillaries or veins. Staining for both receptors was also present in arterial walls from the fallopian tube (isthmus and ampulla) and vagina but not in arteries of nonreproductive tissues (intestinal, renal, hepatic, femoral, and pulmonary arteries, aorta). PR immuno-staining was increased by estrogen in all cell types of the rabbit uterus, but the doses necessary to provoke an intense nuclear staining in uterine arteries were higher than those required for observing strong labeling in glandular, stromal, or myometrial cells. These results suggest that, contrary to many hypotheses previously put forward, sex steroid hormones may regulate uterine blood flow through a direct effect on uterine arterial walls.

Aligning tumor mutational burden (TMB) quantification across diagnostic platforms: phase II of the Friends of Cancer Research TMB Harmonization Project

BACKGROUND

Tumor mutational burden (TMB) measurements aid in identifying patients who are likely to benefit from immunotherapy; however, there is empirical variability across panel assays and factors contributing to this variability have not been comprehensively investigated. Identifying sources of variability can help facilitate comparability across different panel assays, which may aid in broader adoption of panel assays and development of clinical applications.

MATERIALS AND METHODS

Twenty-nine tumor samples and 10 human-derived cell lines were processed and distributed to 16 laboratories; each used their own bioinformatics pipelines to calculate TMB and compare to whole exome results. Additionally, theoretical positive percent agreement (PPA) and negative percent agreement (NPA) of TMB were estimated. The impact of filtering pathogenic and germline variants on TMB estimates was assessed. Calibration curves specific to each panel assay were developed to facilitate translation of panel TMB values to whole exome sequencing (WES) TMB values.

RESULTS

Panel sizes >667 Kb are necessary to maintain adequate PPA and NPA for calling TMB high versus TMB low across the range of cut-offs used in practice. Failure to filter out pathogenic variants when estimating panel TMB resulted in overestimating TMB relative to WES for all assays. Filtering out potential germline variants at >0% population minor allele frequency resulted in the strongest correlation to WES TMB. Application of a calibration approach derived from The Cancer Genome Atlas data, tailored to each panel assay, reduced the spread of panel TMB values around the WES TMB as reflected in lower root mean squared error (RMSE) for 26/29 (90%) of the clinical samples.

CONCLUSIONS

Estimation of TMB varies across different panels, with panel size, gene content, and bioinformatics pipelines contributing to empirical variability. Statistical calibration can achieve more consistent results across panels and allows for comparison of TMB values across various panel assays. To promote reproducibility and comparability across assays, a software tool was developed and made publicly available.

Importance of time to reperfusion on outcomes with primary coronary angioplasty for acute myocardial infarction (results from the Stent Primary Angioplasty in Myocardial Infarction Trial)

The mortality benefit of thrombolytic therapy for acute myocardial infarction (AMI) is strongly dependent on time to treatment. Recent observations suggest that time to treatment may be less important with primary percutaneous transluminal coronary angioplasty (PTCA). Patients with AMI of <12 hours duration, without cardiogenic shock, who were treated with primary PTCA from the Stent PAMI Trial (n = 1,232) were evaluated to assess the effect of time to reperfusion on outcomes. Thrombolysis In Myocardial Infarction grade 3 flow was achieved in a high proportion of patients regardless of time to treatment. Improvement in ejection fraction from baseline to 6 months was substantial with reperfusion at <2 hours but was modest and relatively independent of time to reperfusion after 2 hours (<2 hours, 12.3% vs > or =2 hours, 4.2%, p = 0.004). There were no differences in 1- or 6-month mortality by time to reperfusion (6-month mortality: <2 hours [5.5%], 2 to <4 hours [4.6%], 4 to <6 hours [4.5%], >6 hours [4.2%], p = 0.97). There were also no differences in other clinical outcomes by time to reperfusion, except that reinfarction and infarct artery reocclusion at 6 months were more frequent with later reperfusion. The lack of correlation between time to treatment and mortality in patients without cardiogenic shock suggests that the survival benefit of primary PTCA may be related principally to factors other than myocardial salvage. These data may also have implications regarding the triage of patients with AMI for primary PTCA.