Plasma membrane Ca2+ ATPase 1 (PMCA1) but not PMCA4 is critical for B-cell development and Ca2+ homeostasis in mice

The amplitude and duration of Ca²⁺ signaling is crucial for B-cell development and self-tolerance; however, the mechanisms for terminating Ca²⁺ signals in B cells have not been determined. In lymphocytes, plasma membrane Ca²⁺ ATPase (PMCA) isoforms 1 and 4 (PMCA1 and PMCA4, aka ATP2B1 and ATP2B4) are the main candidates for expelling Ca²⁺ from the cell through the plasma membrane. We report here that Pmca4 (Atp2b4) KO mice had normal B-cell development, while mice with a conditional KO of Pmca1 (Atp2b1) had greatly reduced numbers of B cells, particularly splenic follicular B cells, marginal zone B cells, and peritoneal B-1a cells. Mouse and naïve human B cells showed only PMCA1 expression and no PMCA4 by western blot, in contrast to T cells, which did express PMCA4. Calcium handling was normal in Pmca4^−/− B cells, but Pmca1 KO B cells had elevated basal levels of Ca²⁺, elevated levels in ER stores, and reduced Ca²⁺ clearance. These findings show that the PMCA1 isoform alone is required to ensure normal B-cell Ca²⁺ signaling and development, which may have implications for therapeutic targeting of PMCAs and Ca²⁺ in B cells.     

One-stage breast reduction and nipple-areolar reconstruction

The authors present an easily designed and accomplished technique of one-stage reduction mammaplasty and nipple-areolar reconstruction for patients with large or medium-size breasts and for patients missing the nipple-areolar complex. The technique has low inherent risks, and the symmetry of the breast is maintained to the maximum. In addition to the cosmetic improvement, using this technique benefits the patient further by avoiding postoperative corrections or adjustments.     

Three-axis ellipsoidal fitting of videokeratoscopic height data after penetrating keratoplasty

PURPOSE: After penetrating keratoplasty corneal topography tends to be irregular and the fitting of spectacle glasses or contact lenses may be difficult. The purpose of this study was to demonstrate a mathematical method for approximation of discrete corneal topography height data with an ellipsoid for better appreciation of the clinical outcome after PK. PATIENTS AND METHODS: In 50 eyes (30 keratoconus, 20 Fuchs' dystrophy) penetrating keratoplasty was performed using nonmechanical trephination with the excimer laser 193 nm. Main outcome measures were objective corneal astigmatism (regular keratometry, corneal topography (TMS-1)), subjective refraction and best-corrected visual acuity (VA) in a fixed postoperative gate 3 and 12 month postoperatively and after suture removal. An approximation algorithm was applied for fitting a general ellipsoidal surface (not rotationally symmetric) to raw corneal topography height data. A set of parameters (meridional power, axis and asphericity) were calculated. The root mean square error (RMS) was determined between raw topography power data and the ellipsoidal model surface within an apical distance of 3 mm. The cylinder of subjective refraction was correlated with the keratometric readings, the Simulated Keratometry (SimK) of the topography system and the respective parameters of the model surface. RESULTS: The amount of the SimK cylinder yielded higher values than keratometry and the ellipsoidal fit; subjective refraction yielded the lowest value at each follow-up interval. The ellipsoidal fit showed the best correlation to the refractive cylinder at all follow-up stages (p = 0.04 at 3, p = 0.01 at 12 months and p = 0.002 after suture removal). The axis of the best ellipsoidal fit showed a significant correlation with the axis of the refractive cylinder at all follow-up intervals (p = 0.02 at 3 months, p = 0.01 before suture removal and p = 0.002 after suture removal). The axis of the keratometric cylinder showed a mild correlation at all follow-up examinations (p = 0.05 at 3 months, p = 0.02 before suture removal and p = 0.04 after suture). The cylinder of the topographic modeling system, however, showed a significant correlation with the refractive cylinder axis only after suture removal (p = 0.04). The paracentral corneal power of SimK (45.9D at 3 months, 44.4D at 12 months and 43.0D after suture removal) exceeded the respective values of conventional keratometry (43.1D at 3 months, 42.9D at 12 months and 41.7D after suture removal) and the ellipsoidal fit (43.3D at 3 months, 43.0D at 12 months and 41.8D after suture removal). The corneal asphericity from the ellipsoidal fit reached an approximately spherical shape in radial direction (A = 1.0) in the initial time period after penetrating keratoplasty, remained stable before suture removal and decreased significantly (p = 0.02) to a final value of A = 0.86 indicating a (normal) prolate shape of the cornea. The approximation error between the raw corneal topography height data and the best ellipsoidal fit model surface was nearly unchanged before suture removal (1.8 +/- 0.7 microm at 3 months and 1.9 +/- 1.1 microm at 12 months, p = 0.30) and decreased significantly to the examination after suture removal (0.9 +/- 0.5 microm, p = 0.01). CONCLUSIONS: The approximation of corneal topography height data with an ellipsoidal model surface renders reconstruction of clinically relevant corneal topography parameters including corneal asphericity. Even in markedly irregular corneal surfaces, such as after PK, the correlation of amount/axis of refractive cylinder with the model surface parameters is more accurate than with respective SimK values of corneal topography analysis.     

Ocular Manifestation of Mucopolysaccharidosis I-S (Scheie's Syndrome)

BACKGROUND: Bilateral stromal corneal opacifications are a differential diagnostical challenge to identify associated systemic diseases. CASE-REPORT: A 47-year old civil engineer (height 167 cm) with bilateral stromal corneal clouding presented with visual loss for the last 27 years: VA 20/100 OD and 20/50 OS (following penetrating keratoplasty OS). The cornea showed milky-whitish, cloudy, diffuse stromal deposits without a separate lipoid arc. The posterior segment showed tapetoretinal degeneration. Scotopic ERG was decreased. A suspicious stiffness of interphalangeal joints on both hands was observed. There was an aortic and mitral insufficiency grade I. Serum levels of LDL, HDL and triglycerides were normal. The biomicroscopical diagnosis of Scheie's syndrome (mucopolysaccharidosis I-S) was confirmed by a deficiency of alpha-L-iduronidase in leukocytes (0.02 nmol/min/mg protein, normal range: 0.3 - 1.5). CONCLUSION: The differential diagnosis of bilateral corneal stromal opacification includes in addition to the mucopolysaccharidoses HDL-deficiency diseases (LCAT deficiency, Tangier disease, Fish eye disease), Schnyder's crystalline stromal dystrophy, cystinosis, gout and mucolipidoses. MPS I-S may easily be detected by alpha-L-iduronidase deficiency in leukocytes and increased mucopolysaccharides in the urine. Furthermore, patients with MPS I-S need general medical care because of cardiovascular abnormalities, joint stiffness and myopathies.     

Superficial corneal effects of experimental nonmechanical penetrating keratoplasty using a Q-switched Er:YAG laser

PURPOSE: To assess thermal effects of Q-switched Er:YAG laser trephination to corneal epithelium and superficial stroma using different mask types and materials for experimental penetrating keratoplasty. METHODS: Laser trephination was performed in 20 freshly-enucleated porcine eyes (repetition rate 5 Hz, pulse energy 65 mJ, spot size 0.7 mm). We used flat, open-metal and ceramic masks for donor and recipient trephination placed directly onto the corneal surface. Main outcome measures as assessed by light microscopy after PAS staining of 8-microm paraffin sections included: extension of tissue thermal damage at the cut edge in the superficial and basal epithelial layers, the basement membrane and subepithelial stroma, and depth and width of epithelial/stromal involvement in the area of the donor mask contact. RESULTS: The thermal damage in the superficial epithelium was more pronounced in donor (mean extension 61.6 +/- 15.6 microm) than in recipient (29.4 +/- 24.9 microm, p= 0.05) trephination. In donor trephination, thermal damage zone of the superficial epithelial layer was significantly smaller with ceramic than with metal masks (21.0 +/- 23.0 versus 61.6 +/- 15.6 microm, p= 0.014). In contrast, differences at basal epithelial layer (p= 0.44), basement membrane (p= 0.79), and subepithelial stroma (p= 0.2) were not statistically significant. Superficial donor involvement of the cornea adjacent to the paracentral donor mask contact zone was seen neither with ceramic nor with metal masks. CONCLUSION: Superficial corneal alterations adjacent to the mask-cornea contact zone may be minimized by using the Er:YAG laser in a Q-switched mode. Ceramic masks, in contrast to metal masks, further reduce superficial thermal alterations at the cut edge.     

Risk factors for corneal allograft rejection: intermediate results of a prospective normal-risk keratoplasty study

PURPOSE: To analyze the incidence of and possible risk factors for endothelial corneal allograft rejection in a well-defined population following penetrating normal-risk keratoplasty. METHODS: Since 1996 a longitudinal prospective study has been conducted to analyze the results of normal-risk penetrating keratoplasty. All patients underwent a standardized protocol of follow-up treatment and examinations in our institution. Diagnosis of corneal endothelial rejection was based on slit-lamp biomicroscopy and laser flare photometry. Data were analyzed using a proportional hazard model for censored data (Cox model), and Kaplan-Meier survival curves. The following parameters were analyzed: age, gender, atopic dermatitis, dry eye symptoms of the recipient; surgeon, graft diameter, post-mortem time, storage time and graft preservation method; and duration of postoperative epithelial defects. RESULTS: Between 1996 and May 2001, 397 patients were recruited and followed with a median follow-up of 18 months. Episodes of endothelial graft rejection were observed in 22 patients (5.5%; 18 eyes with acute diffuse episodes and 4 eyes with chronic focal rejection episodes). In addition, 12 eyes (3%) showed isolated small keratic precipitates ("graft rejection suspects"). All but one graft regained clarity after topical and systemic steroid treatment. Most episodes occurred 11-18 months postoperatively. The percentage of grafts without any episode of endothelial allograft rejection was 95% after 12 months, 89% after 18 months, and 86.5% after 24 months. The following factors were associated with graft rejection: atopic dermatitis (P=0.021), clinically manifest tear insufficiency (P=0.007), and short duration of graft storage (P=0.008). No significant correlation was detected for the remainder of the analyzed factors (P>0.05). CONCLUSION: The incidence of episodes of corneal endothelial allograft rejection following normal-risk keratoplasty was 13.5% within the first two postoperative years. However, the frequency of irreversible immunologic graft failure (3 per thousand) was lower than reported in the literature. Patients should be regularly followed up for at least 18 months postoperatively. Patients with underlying atopic dermatitis or dry eyes should receive special ophthalmological care.     

La Crosse encephalitis in Eastern Tennessee: clinical,environmental, and entomological characteristics from a blinded cohort study

A blinded cohort study was conducted in 2000 to better understand the emergence of La Crosse virus infection in eastern Tennessee, with special emphasis on the potential mosquito vector(s). Children with suspected central nervous system infection were enrolled at the time of clinical presentation at a large pediatric referral hospital. Clinical, environmental, and entomological data were collected prior to case confirmation. Sixteen of the 40 children included in the final analysis were confirmed to have La Crosse infection by a fourfold increase in antibody titers between collection of acute- and convalescent-phase sera. Factors significantly associated with La Crosse infection included average number of hours per day spent outdoors (5.9 for La Crosse virus cases vs. 4.0 for noncases, p = 0.049); living in a residence with one or more tree holes within 100 m (relative risk = 3.96 vs. no tree holes within 100 m, p = 0.028); and total burden of Aedes albopictus (number of female and male larvae and adults collected at a site), which was more than three times greater around the residences of La Crosse virus cases versus noncases (p = 0.013). Evidence is accumulating that the newly introduced mosquito species Ae. albopictus may be involved in the emergence of La Crosse virus infection in eastern Tennessee.