Introduction of high-sensitivity troponin assays: impact on myocardial infarction incidence and prognosis.

OBJECTIVE: The study objective was to compare the incidence and prognosis of acute myocardial infarction when using high-sensitivity cardiac troponin assays instead of a standard cardiac troponin assay for the diagnosis of acute myocardial infarction. METHODS: In a prospective international multicenter study, we enrolled 1124 consecutive patients presenting with suspected acute myocardial infarction. Final diagnoses were adjudicated by 2 independent cardiologists 2 times using all available clinical information: first using standard cardiac troponin levels and second using high-sensitivity cardiac troponin T levels for adjudication. Patients were followed up for a mean of 19±9 months. RESULTS: The use of high-sensitivity cardiac troponin T instead of standard cardiac troponin resulted in an increase in the incidence of acute myocardial infarction from 18% to 22% (242 vs 198 patients), a relative increase of 22%. Of the 44 additional acute myocardial infarctions, 35 were type 1 acute myocardial infarctions and 9 were type 2 acute myocardial infarctions. This was accompanied by a reciprocal decrease in the incidence of unstable angina (unstable angina, 11% vs 13%). The most pronounced increase was observed in patients adjudicated with cardiac symptoms of origin other than coronary artery disease with cardiomyocyte damage (83 vs 31 patients, relative increase of 268%). Cumulative 30-month mortality rates were 4.8% in patients without acute myocardial infarction, 16.4% in patients with a small acute myocardial infarction detected only by high-sensitivity cardiac troponin T but not standard cardiac troponin, and 23.9% in patients with a moderate/large acute myocardial infarction according to standard cardiac troponin assays and high-sensitivity cardiac troponin T (P<.001). CONCLUSIONS: The introduction of high-sensitivity cardiac troponin assays leads to only a modest increase in the incidence of acute myocardial infarction. The novel sensitive assays identify an additional high-risk group of patients with increased mortality, therefore appropriately classified with acute myocardial infarction (Advantageous Predictors of Acute Coronary Syndromes Evaluation; NCT00470587).

Sulcus implantation of a single-piece foldable acrylic intraocular lens after posterior capsular rupture in cataract surgery.

PURPOSE: To evaluate the safety of a foldable acrylic single-piece intraocular lens (IOL) in cases of complicated cataract surgery and sulcus implantation. The setting was University and private anterior segment surgery practices. METHODS: In this observational case series study, 13 eyes of 13 patients were included after complicated phacoemulsification with extensive posterior capsule rupture with or without vitreous loss. A foldable acrylic single-piece IOL (Rayner Superflex 620H; Rayner Intraocular Lenses Limited, Hove, East Sussex, UK) was implanted in the ciliary sulcus in each eye. Postoperative follow-up included best-corrected visual acuity, anterior segment biomicroscopy, IOL centration and position, intraocular pressure, and fundus biomicroscopy. Optical coherence tomography was performed in 2 subjects. Median follow-up time was 12 months (range 1-21 months). RESULTS: Visual acuity 12 months after surgery was 6/18 and below in 5 eyes (39%), between 6/12 and 6/7.5 in 6 eyes (46%), and 6/6 in 2 eyes (15%). All patients experienced vision improvement. Postoperative complications included corneal edema (2 eyes), Descemet folds (1 eye), intraocular pressure elevations (3 eyes), and pronounced anterior segment inflammation (1 eye). Two eyes had minor pupil contour abnormalities. No significant IOL decentration was observed. CONCLUSIONS: Sulcus implantation of a foldable acrylic single-piece IOL in eyes with complicated cataract surgery maintains the advantages of easy insertion and small incision. Postoperatively, all IOLs were centered, visual results were good, and complications were manageable and not IOL-related.

Modulation of central corneal thickness by various riboflavin eyedrop compositions in porcine corneas.

PURPOSE: To evaluate the modulatory effect of various riboflavin 0.1% and 0.2% compositions on the central corneal thickness (CCT) in fresh porcine corneas. SETTING: Department of Ophthalmology, Johannes Gutenberg University of Mainz, Mainz, Germany. DESIGN: Experimental study. METHODS: The CCT in freshly enucleated porcine globes was measured by ultrasound pachymetry before and after (if applicable) deepithelialization and every 10 minutes thereafter during 120 minutes of eyedrop application. In Groups 1 and 2 (controls), no eyedrops were applied. In Groups 3 and 4, isotonic riboflavin eyedrops were used. In Groups 5 to 9, hypotonic riboflavin eyedrops were given. In Groups 10 and 11, preparations for transepithelial crosslinking were applied. In Groups 2 to 9, deepithelialization was performed. The final CCT in the groups was compared by analysis of variance. RESULTS: One hundred ten freshly enucleated porcine globes were used. The mean final CCT compared with preoperative values was 97% ± 4% (SD) in Group 1, 91% ± 4% in Group 2, 66% ± 5% in Group 3, 151% ± 13% in Group 4, 65% ± 2% in Group 5, 105% ± 3% in Group 6, 120% ± 4% in Group 7, 130% ± 4% in Group 8, 132% ± 4% in Group 9, 114% ± 2% in Group 10, and 114% ± 4% in Group 11. The differences between Group 1 and each of Groups 3, 4, 5, 7, 8, and 9 were statistically significant (P<.05). CONCLUSION: There was considerable variation in the final CCT as a result of varying riboflavin eyedrop compositions. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Ebola virion attachment and entry into human macrophages profoundly effects early cellular gene expression.

Zaire ebolavirus (ZEBOV) infections are associated with high lethality in primates. ZEBOV primarily targets mononuclear phagocytes, which are activated upon infection and secrete mediators believed to trigger initial stages of pathogenesis. The characterization of the responses of target cells to ZEBOV infection may therefore not only further understanding of pathogenesis but also suggest possible points of therapeutic intervention. Gene expression profiles of primary human macrophages exposed to ZEBOV were determined using DNA microarrays and quantitative PCR to gain insight into the cellular response immediately after cell entry. Significant changes in mRNA concentrations encoding for 88 cellular proteins were observed. Most of these proteins have not yet been implicated in ZEBOV infection. Some, however, are inflammatory mediators known to be elevated during the acute phase of disease in the blood of ZEBOV-infected humans. Interestingly, the cellular response occurred within the first hour of Ebola virion exposure, i.e. prior to virus gene expression. This observation supports the hypothesis that virion binding or entry mediated by the spike glycoprotein (GP(1,2)) is the primary stimulus for an initial response. Indeed, ZEBOV virions, LPS, and virus-like particles consisting of only the ZEBOV matrix protein VP40 and GP(1,2) (VLP(VP40-GP)) triggered comparable responses in macrophages, including pro-inflammatory and pro-apoptotic signals. In contrast, VLP(VP40) (particles lacking GP(1,2)) caused an aberrant response. This suggests that GP(1,2) binding to macrophages plays an important role in the immediate cellular response.

Biaxial microincision versus coaxial small-incision cataract surgery in complicated cases.

PURPOSE: To evaluate and compare the results of biaxial microincision and coaxial small-incision surgery in patients with cataract with coexisting exfoliation syndrome, uveitis, anterior or posterior synechias, phacodonesis, or previous intraocular surgery over an 8-week follow-up. SETTING: Department of Ophthalmology, Mainz University, Mainz, Germany. METHODS: Eyes were prospectively assigned (1:1) to have biaxial microincision (<1.5 mm) phacoemulsification or coaxial small-incision (2.8 mm) phacoemulsification using pulsed ultrasound energy (Sovereign WhiteStar) with variable duty cycles followed by implantation of a microincision intraocular lens. Intraoperative and postoperative complications, corrected distance visual acuity (CDVA), laser flare photometry values, effective phacoemulsification time (EPT), and endothelial cell count (ECC) were evaluated. RESULTS: The study enrolled 94 eyes. There were no statistically significant differences between the techniques in intraoperative or postoperative complications. The most frequent postoperative complications were corneal edema surrounding the incision (40%, biaxial group; 35%, coaxial group), pupil distortion (3% versus 7%), and fibrin exudation (3% versus 3%). No other postoperative complications occurred. The median EPT was statistically significantly shorter (1.34 seconds versus 5.4 seconds) and the median phaco power significantly lower (3.3% versus 12.9%) in the biaxial group than in the coaxial group (P<.001). There were no differences between groups in CDVA, laser flare photometry values, or ECC. CONCLUSIONS: The EPT was shorter and the mean phaco power lower with biaxial phacoemulsification, perhaps because of better access of the phaco handpiece for grooving the nucleus with this technique. The 2 techniques were comparable in intraoperative and postoperative complications. FINANCIAL DISCLOSURE: No other author has a financial or proprietary interest in any material or method mentioned.

Optical coherence tomography of macular thickness after biaxial vs coaxial microincision clear corneal cataract surgery.

PURPOSE: To evaluate macular thickness changes after biaxial microincision versus coaxial small incision cataract surgery using optical coherence tomography (OCT). METHODS: This prospective, randomized, marked study comprised 70 patients (70 eyes) undergoing biaxial microincision surgery or conventional coaxial phacoemulsification. Patients were evaluated by Stratus OCT preoperatively and 1 day, 4 weeks, and 8 weeks postoperatively. Best-corrected visual acuity (BCVA), phacoemulsification power, and effective phacoemulsification time (EPT) were evaluated. RESULTS: In the biaxial group, median foveal thickness changed from 160 microm preoperatively to 168 microm 8 weeks postoperatively (p=0.018), while median macular volume increased from 2.43 mm3 to 2.57 mm3 (p<0.001). In the coaxial group, median foveal thickness increased from 164 microm preoperatively to 170 microm 8 weeks postoperatively (p=0.082), while median macular volume changed from 2.45 mm3 to 2.55 mm3 (p<0.001). No significant differences in the intraindividual increase of foveal thickness and macular volume were found between groups at 8 weeks. A statistically significant difference between groups was found in median foveal thickness at day 1 postoperatively (p=0.027). No significant differences between groups in median macular volume were found at day 1 or at 4 and 8 weeks postoperatively. Median phacoemulsification power was 7.1% and EPT 2.4 seconds in the biaxial group versus 10.6% and 3.2 seconds in the coaxial group (p<0.001 and p=0.078). CONCLUSIONS: No clinically relevant differences in foveal thickness or macular volume were observed after biaxial microincision and coaxial small incision clear corneal cataract surgery. The blood-retinal barrier did not seem to be influenced by either procedure.

Contrast sensitivity after implantation of a spherical versus an aspherical intraocular lens in biaxial microincision cataract surgery.

PURPOSE: To determine whether implantation of a microincision intraocular lens (IOL) with a modified anterior surface, designed to compensate for the positive spherical aberration of the cornea in eyes of cataract patients, results in improved pseudophakic quality of vision in pseudophakic eyes after biaxial microincision phacoemulsification. SETTING: Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany. METHODS: In a nonrandomized parallel cohort investigation, the visual performance of 52 eyes of 52 patients unilaterally implanted with the aspherical Acri. Smart 36 A IOL (Acri.Tec) were compared with those of 25 eyes of 25 age-matched patients unilaterally implanted with the spherical Acri. Smart 46 S IOL (Acri.Tec). Eight weeks after surgery, the following parameters were assessed: uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), pupil size under various illumination conditions, high-contrast and low-contrast visual acuities, photopic and mesopic contrast sensitivities, capsulorhexis size, and wavefront aberration of the cornea and eye. The primary clinical endpoint of the comparison was defined as the area under the cycles per degree (cpd) curve of the contrast sensitivity profile. RESULTS: The aspherical IOL group and the spherical IOL group did not differ in baseline characteristics. The median age was 71 years and 68% were women in the aspherical group versus 69 years and 62% women in the spherical group. The preoperative median UCVA was 20/80 in both groups. The UCVA, BCVA, pupil size, and capsulorhexis size were not statistically different between the 2 groups. Furthermore, no clinically relevant or statistically significant between-group differences were observed in the primary clinical endpoint. The median postoperative low mesopic contrast sensitivity without glare was 73 cpd in the aspherical group and 84 cpd in the spherical group (P = .624); a similar tendency was observed under high mesopic conditions (median 80 cpd and 83 cpd, respectively) (P = 1.000). Implantation of both IOL types resulted in a negative spherical aberration Z(4)(0), which was significantly different between the 2 groups (median -0.09 mum aspherical and -0.29 microm aspherical at a pupil size of 4.5 mm) (P<.001). CONCLUSIONS: No clinically relevant postoperative differences in contrast sensitivity were observed between the aspherical microincision IOL and the spherical equivalent model. The development of microincision IOLs, which fit through corneal incisions smaller than 2.0 mm and improve night-driving conditions (eg, reduction of glare), could optimize modern biaxial cataract surgery.

Effect of a closed foldable equator ring on capsular bag shrinkage in cataract surgery.

PURPOSE: To evaluate the effect of a closed foldable equator ring (CFER) versus a conventional capsular tension ring (CTR) on capsular bag shrinkage. SETTING: Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany. METHODS: In this prospective study, 70 eyes of 70 patients were randomized to 2 groups using a 1:1 block scheme. After uneventful cataract surgery, a capsular measuring ring was implanted in all eyes to measure the capsular bag diameter in vivo. In Group 1, a CTR was implanted in the capsular bag. In Group 2, a CFER was inserted. Biometric characteristics such as axial length and the horizontal and vertical corneal radii were measured preoperatively. The capsular bag diameter and capsulorhexis diameter were measured intraoperatively and 2 or 3 days as well as 1 and 3 months postoperatively. RESULTS: There were no statistically significant or clinically relevant between-group differences in covariants such as axial length, vertical and horizontal corneal radii, and capsulorhexis diameter. Eyes with the CTR had slight but statistically significant capsular bag shrinkage from a median of 10.4 to a median of 10.2 mm after 3 months (P<.001). Eyes with the CFER also had slight but statistically significant capsular bag shrinkage from a median of 10.3 to a median of 10.2 mm 3 months postoperatively (P = .021). At baseline, the CTR group had a larger capsular bag diameter, but there were no statistically significant differences between the groups at the 3-month follow-up (P = .669). CONCLUSIONS: No clinically relevant capsular bag shrinkage was observed after implantation of a CFER or a CTR. The expected capsular bag shrinkage was the same in both groups.

Biaxial microincision versus coaxial small-incision clear cornea cataract surgery.

OBJECTIVE: To compare clinical outcomes of biaxial microincision (1.5 mm) and coaxial small-incision (2.75 mm) clear cornea cataract surgery. DESIGN: Randomized controlled clinical trial. PARTICIPANTS: Seventy eyes of 70 patients were examined at a German university eye hospital. INTERVENTION: The 70 patients (70 eyes) were assigned randomly (1:1) to a biaxial or conventional coaxial incision group. Both groups underwent phacoemulsification using pulsed ultrasound energy with variable duty cycles, followed by microincision intraocular lens implantation. MAIN OUTCOME MEASURES: Best-corrected visual acuity (BCVA), astigmatism, laser flare photometry value, effective phacoemulsification time (EPT), and endothelial cell count were evaluated. RESULTS: The treatment groups did not differ in baseline characteristics (median BCVA of 20/40 preoperatively in both groups, P = 0.97). On postoperative day 1, BCVA was better in the biaxial group than in the coaxial group (20/25 vs. 20/33, P = 0.018). Eight weeks after surgery, median BCVAs were 20/20 in the biaxial group and 20/25 in the coaxial group (P = 0.015). Median changes in astigmatism were -0.15 diopters (D) in the biaxial group and -0.31 D in the coaxial group. Neither clinically relevant nor statistically significant differences were found in laser flare photometry values. Effective phacoemulsification time was >3 seconds in only 34% of biaxial procedures, versus 68% of coaxial procedures (P = 0.013). At 8 weeks after surgery, endothelial cell counts were decreased similarly in the biaxial (14.5%) and coaxial (14.1%) groups (P = 0.408). CONCLUSIONS: With the biaxial microincision technique, EPT is shorter and BCVA improves more rapidly, with no difference in astigmatism, laser flare photometry results, or endothelial cell count relative to the coaxial small-incision technique for phacoemulsification.

Epidemiological evaluation of intraoperative antibiosis as a protective agent against endophthalmitis after cataract surgery.

PURPOSE: To evaluate risk factors for endophthalmitis after cataract surgery and to retest recent findings on the protective effect of intraoperative antibiosis and the promoting effect of the clear corneal as compared to sclerocorneal incision. DESIGN: Survey study. PARTICIPANTS: Five hundred thirty-eight ophthalmosurgical centers in Germany. MAIN OUTCOME MEASURE: Responder specific endophthalmitis incidence. RESULTS: A total of 310 (58%) questionnaires were computed resulting in an overall count of 404 356 cataract surgeries and 291 self-reported endophthalmitis cases (crude rate 0.072%). The risk of postoperative endophthalmitis for sclerocorneal versus clear corneal incisions was not significantly reduced (relative risk 0.97, 99% confidence interval 0.69-1.38). The hypothesis of a protective effect of intraocular antibiosis could be confirmed by a significantly decreased risk ratio of 0.69 (99% confidence interval 0.48-0.99) indicating a significant benefit from intraoperative intraocular antibiosis. A similar tendency was observed for an intraoperative periocular antibiosis with a significantly reduced risk ratio of 0.68 (99% confidence interval 0.49-0.96). These risk estimates had been adjusted for the size of the surgical center: a significantly reduced risk ratio of 0.70 (99% confidence interval 0.49-0.98) for postoperative endophthalmitis was observed for local centers. CONCLUSIONS: Whereas this 2001 appraisal of a survey in 1996 could not reproduce the benefit of sclerocorneal incision, the protective effect of intraoperative intraocular antibiotic prophylaxis could be confirmed. However, the results of this survey have to be interpreted with care, since it is not based on individual case information, but rather on aggregate questionnaire data.

Capsular bag shrinkage after implantation of a capsular bending or capsular tension ring.

PURPOSE: To evaluate the influence of a capsular bending ring (CBR) or tension ring (CTR) on capsular bag shrinkage. SETTING: Department of Ophthalmology, Johannes Gutenberg-University, and Department of Medical Biometry, Epidemiology and Informatics, University of Mainz, Mainz, Germany. METHODS: In 92 eyes of 92 patients, a capsular measuring ring (CMR) was implanted after phacoemulsification to measure capsular bag size in vivo. Patients were randomized into 3 groups: The first received a CMR and CBR, the second received a CMR and CTR, and the third received a CMR alone. Measurements were performed preoperatively, intraoperatively, during the first 3 postoperative days, and after 1 and 3 months. Preoperative biometric characteristics such as axial length (AL) and anterior chamber depth were determined. Primary clinical end points were capsular bag size and capsulorhexis diameter measured intraoperatively and by means of slitlamp biomicroscopy and retroillumination photography postoperatively. RESULTS: There were no clinically relevant group differences in AL, anterior chamber depth, or capsulorhexis diameter. Eyes implanted with the CBR showed shrinkage of the capsular bag from 10.6 to 10.4 mm after a median of 3 months (sign test; P = .023); eyes with a CTR showed comparable median capsular bag shrinkage from 10.5 to 10.2 mm (P<.001), whereas eyes without a CTR showed a median shrinkage from 10.5 to 10.0 mm (P<.001). Intraindividual shrinkage was of a similar, although significantly different, order among these groups (median shrinkage 0.15 versus 0.23 and 0.38 mm, respectively; all pairwise Wilcoxon test; P = .050, P = .020, P<.001, respectively). CONCLUSIONS: Capsular shrinkage can be inhibited by a CBR and, to lesser extent, a CTR; the gain in shrinkage prevention is limited when compared with a CMR, however. This conclusion can be drawn only for the specific CBR or CTR and hydrophobic acrylic intraocular lens (IOL) used in this study. Reduction of capsular bag shrinkage after CTR implantation may reduce IOL dislocation and tilt and help to maintain postoperative visual acuity.

Role of Ebola virus secreted glycoproteins and virus-like particles in activation of human macrophages.

Ebola virus, a member of the family Filoviridae, causes one of the most severe forms of viral hemorrhagic fever. In the terminal stages of disease, symptoms progress to hypotension, coagulation disorders, and hemorrhages, and there is prominent involvement of the mononuclear phagocytic and reticuloendothelial systems. Cells of the mononuclear phagocytic system are primary target cells and producers of inflammatory mediators. Ebola virus efficiently produces four soluble glycoproteins during infection: sGP, delta peptide (Delta-peptide), GP(1), and GP(1,2Delta). While the presence of these glycoproteins has been confirmed in blood (sGP) and in vitro systems, it is hypothesized that they are of biological relevance in pathogenesis, particularly target cell activation. To gain insight into their function, we expressed the four soluble glycoproteins in mammalian cells and purified and characterized them. The role of the transmembrane glycoprotein in the context of virus-like particles was also investigated. Primary human macrophages were treated with glycoproteins and virus-like particles and subsequently tested for activation by detection of several critical proinflammatory cytokines (tumor necrosis factor alpha, interleukin-6 [IL-6], and IL-1 beta) and the chemokine IL-8. The presentation of the glycoprotein was determined to be critical since virus-like particles, but not soluble glycoproteins, induced high levels of activation. We propose that the presentation of GP(1,2) in the rigid form such as that observed on the surface of particles is critical for initiating a sufficient signal for the activation of primary target cells. The secreted glycoproteins do not appear to play any role in exogenous activation of these cells during Ebola virus infection.

Monocular versus binocular pupillometry.

PURPOSE: To quantify differences between monocular and binocular pupil size measurement under scotopic and mesopic conditions. SETTING: Department of Ophthalmology, Johannes Gutenberg-University, and Department of Medical Biometry, Epidemiology and Informatics, University of Mainz, Mainz, Germany. METHODS: Computerized dynamic pupillometry (P2000 SA, Procyon Instruments Ltd.) was used at 3 illumination levels: scotopic at 0.03 lux, mesopic low at 0.82 lux, and mesopic high at 6.4 lux. One hundred forty eyes of 70 healthy volunteers without ocular pathology were examined. The subjects were divided into 2 groups. In the first group, the pupil diameter was measured binocularly first. In the second group, monocular measurement was performed first. For statistical analysis, data description was based on medians and quartiles of the respective pupil diameter measurements. Intraindividual significance was based on sign tests, and interindividual comparison were based on 2-sample Wilcoxon tests. RESULTS: In all eyes, statistically significant differences were found in pupil size, with higher values for the monocular measurement under low and high mesopic conditions (P=.000). For scotopic conditions, a trend toward higher values in monocular measurement was observed that approached statistical significance. CONCLUSIONS: Results indicate that binocular measurement may imitate the patient's life conditions more realistically. Therefore, in eyes with a large pupil diameter with the risk for postoperative scotopic phenomena, binocular measurement should be considered before refractive surgery.

Spring constants of capsular tension rings.

PURPOSE: To determine the spring constants of several types of capsular tension rings (CTRs). SETTING: Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany. METHODS: Fourteen models of CTRs provided by 9 companies were tested; all were 11.0 mm in diameter. The CTRs were positioned in a special retainer of a material-testing machine and compressed at a constant speed of 10.0 mm per minute. The distance and force values were recorded, and each CTR model was tested 3 times using a new specimen each time. The resulting measurements were used to calculate a mean spring constant for each CTR model. RESULTS: All tested CTRs showed linear proportionality between force and compression distance. Test results were repeatable and precise. Capsular tension rings of the same model had comparable mechanical properties, and different models had different mean spring constants ranging from 0.8162 to 4.5501 mN/mm. CONCLUSIONS: The spring constant of a CTR is a suitable mechanical characteristic to facilitate the choice of CTR model. A CTR with a low spring constant may be advantageous for the management of zonular dialysis, whereas a CTR with a higher spring constant may reduce capsular bag shrinkage more effectively.

IL-7 regulates basal homeostatic proliferation of antiviral CD4+T cell memory.

Heightened protection from infectious disease as conferred by vaccination or pathogen exposure relies on the effective generation and preservation of specific immunological memory. T cells are irreducibly required for the control of most viral infections, and maintenance of CD8(+)T cell memory is regulated by at least two cytokines, IL-7 and IL-15, which support survival (IL-7, IL-15) and basal homeostatic proliferation (IL-15) of specific CD8(+) memory T cells (T(M)). In contrast, the factors governing the homeostasis of pathogen-specific CD4(+)T(M) remain at present unknown. Here, we used a physiologic in vivo model system for viral infection to delineate homeostatic features and mechanisms of antiviral CD4(+)T(M) preservation in direct juxtaposition to CD8(+)T cell memory. Basal homeostatic proliferation is comparable between specific CD4(+) and CD8(+)T(M) and independent of immunodominant determinants and functional avidities but regulated in a tissue-specific fashion. IL-7, identified as the dominant cytokine, and IL-15, an accessory cytokine, regulate basal homeostatic proliferation and survival of antiviral CD4(+)T(M). Interestingly, a role for these cytokines in regulation of CD4(+)T cell memory is not readily discernible in the generic "memory-phenotype" population, apparently a consequence of its heterogeneous composition. We also describe a prominent, nonredundant role for IL-7 in supporting basal homeostatic proliferation of CD8(+)T(M). We propose that homeostatic control of antiviral CD4(+) and CD8(+) T cell memory is fundamentally similar and characterized by quantitative, rather than qualitative, differences.