Niche-specificity and the variable fraction of the Pectobacterium pan-genome.

We compare genome sequences of three closely related soft-rot pathogens that vary in host range and geographical distribution to identify genetic differences that could account for lifestyle differences. The isolates compared, Pectobacterium atrosepticum SCRI1043, P. carotovorum WPP14, and P. brasiliensis 1692, represent diverse lineages of the genus. P. carotovorum and P. brasiliensis genome contigs, generated by 454 pyrosequencing ordered by reference to the previously published complete circular chromosome of P. atrosepticum genome and each other, account for 96% of the predicted genome size. Orthologous proteins encoded by P. carotovorum and P. brasiliensis are approximately 95% identical to each other and 92% identical to P. atrosepticum. Multiple alignment using Mauve identified a core genome of 3.9 Mb conserved among these Pectobacterium spp. Each core genome is interrupted at many points by species-specific insertions or deletions (indels) that account for approximately 0.9 to 1.1 Mb. We demonstrate that the presence of a hrpK-like type III secretion system-dependent effector protein in P. carotovorum and P. brasiliensis and its absence from P. atrosepticum is insufficient to explain variability in their response to infection in a plant. Additional genes that vary among these species include those encoding peptide toxin production, enzyme production, secretion proteins, and antibiotic production, as well as differences in more general aspects of gene regulation and metabolism that may be relevant to pathogenicity.

Reduced intraocular pressure after phacoemulsification and posterior chamber intraocular lens implantation.

PURPOSE: To ascertain whether phacoemulsification with posterior chamber intraocular lens (IOL) implantation causes long-term reduction in intraocular pressure (IOP). SETTING: Private practice, Kempten, Germany. METHODS: Intraocular pressure was measured in both eyes of 120 consecutive patients who were unilaterally phakic after phacoemulsification a mean of 17 months +/- 17 (SD) previously. Mean age of the 36 men and 84 women was 76 +/- 10 years. Data were analyzed using binomial distribution and the Wilcoxon signed-rank test. RESULTS: The median ratio of IOP in the pseudophakic eye to IOP in the phakic eye was 0.83. The IOP was lower in the pseudophakic eye in 96 patients (80%). The median IOP was 12 mm Hg in the pseudophakic eyes and 14 mm Hg in the phakic eyes (P < .001). As measured by the interquartile range, IOP distribution was more centered in the pseudophakic than in the phakic eyes (3 versus 4). The IOP in the pseudophakic eyes remained lower to the last measurement, 5 years postoperatively, and appeared to be independent of patient age. Lower IOP in the pseudophakic eye was consistently present in patients with higher IOP in the phakic eye (16 to 22 mm Hg). CONCLUSION: Phacoemulsification with posterior chamber IOL implantation reduced IOP in most but not all patients with a preoperative IOP of 22 mm Hg or less. This reduction was maintained over several years, with the cause yet to be established. Lower IOP may decrease the risk of subsequent glaucomatous nerve damage in these patients.

Epiretinal membranes after extracapsular cataract surgery(1).

PURPOSE: To determine whether uneventful extracapsular cataract extraction (ECCE) with posterior chamber intraocular lens (PC IOL) implantation induces epiretinal membranes (ERMs). SETTING: Private practice, with statistical evaluation at a university department in Germany. METHODS: This prospective study comprised 296 consecutive patients (332 eyes) who had uneventful ECCE with PC IOL implantation for senile cataract. Eyes were examined within 2 weeks preoperatively and 2 weeks and 6, 9, and 12 months postoperatively. The macula was examined with a 78.0 diopter Volk lens. The main outcome measure was the presence of ERM. The membranes were classified as present when cellophane macular reflex (CMR) or macular pucker (MP) was observed. RESULTS: The median age of the patients was 78 years (range 50 to 97 years). At baseline, ERM was present in 49 of 332 eyes (14.8%), 40 (12.1%) with CMR and 9 (2.7%) with MP. Six months postoperatively, ERM was present in 84 of 332 eyes (25.3%), 72 (21.7%) with CMR and 12 (3.6%) with MP. The difference between the baseline and 6 month incidence was significant (P <.001). All new cases of ERM were of the CMR type. One year after surgery, ERM was present in 54 of 198 eyes (27.3%), 47 (23.7%) with CMR and 7 (3.5%) with MP. The ERMs rarely influenced visual acuity; however, 6 of 12 eyes (50.0%) with MP and 13 of 72 (18.1%) with CMR had metamorphopsia. CONCLUSIONS: The prevalence of ERM increased by 71.4% during the first 6 months after uneventful ECCE with PC IOL implantation. Thereafter, the prevalence remained about the same. Newly formed ERMs were probably induced by the uneventful surgery. Although new-onset membranes usually do not preclude good visual acuity, they can cause metamorphopsia postoperatively.

[Lowering intraocular pressure by phacoemulsification and posterior chamber lens implantation]. / Senkung des intraokularen Drucks durch Phakoemulsifikation und Hinterkammerlinsenimplantation.

It is suspected that PE+PCL will often lower IOP. IOP was measured by Goldmann applanation tonometry in 50 consecutive patients (12 males and 38 females) who were unliterally pseudophacic (28 right and 22 left eyes n.s.). They had an intact posterior capsule and were not suffering from glaucoma. Mean age was 76 +/- 10 years. Time intervals since cataract surgery ranged from 2 to 68 months (mean 15 +/- 17 months). Seventy-four percent (99% confidence interval: 61% < P < 87%) of the patients showed lower IOP (less than 90% of reference value) in the pseudophacic eye. Median IOP in pseudophacic eye was 12 mmHg vs 14 mmHg in phacic control eyes (P < 0.01). These results are in accordance with the hypothesis that PE+PCL usually leads to a long-term reduction in IOP.

[How reproducible and stable is intraocular pressure reduction after extracapsular cataract extraction?]. / Wie reproduzierbar und stabil ist die Augendrucksenkung nach extrakapsulärer Kataraktextraktion?

BACKGROUND: Extracapsular cataract extraction with implantation of a posterior chamber lens (ECCE+PCL) lowers intraocular pressure (IOP) in most eyes. However it is believed that this effect vanishes with time. PATIENTS AND METHODS: We measured IOP by Goldmann applanation tonometry in both eyes of 100 consecutive patients who were either bilaterally phakic, unilaterally pseudophakic or bilaterally pseudophakic. The posterior capsule was intact in all pseudophakic eyes and none of the eyes suffered from glaucoma. RESULTS: Median IOP was 12 mmHg for pseudophakic and 14 mm Hg for phacic eyes (p < 0.0001). The median ratio of IOPpseudophakic/IOPphakic (0.82) in unilaterally pseudophakics was significantly lower than the median ratio of IOP1. pseudophakic eye/IOP2. pseudophakic eye (1.02) in bilaterally pseudophakics (p < 0.0001). The ratio in bilaterally pseudophakic subjects was independent of the time passed since ECCE+PCL. The distribution of the ratio of IOPs was similar for the group of bilaterally pseudophakics and bilaterally phakics. CONCLUSION: We conclude that the amount of lowering of IOP induced by ECCE+PCL is characteristic for each patient. It is well reproducible, when the second eye is operated. The lowering of IOP does not fade with time but is stable. Possibly ECCE+PCL lowers the risk to develop glaucomatous optic nerve damage permanently.

Long-term elevation of intraocular pressure after neodymium: YAG laser posterior capsulotomy.

Uncomplicated extracapsular cataract extraction (EC) followed by posterior chamber lens implantation (PCL) has been shown to cause long-term lowering of intraocular pressure (IOP) in most patients. Since it has been suggested that Neodymium: YAG (Nd:YAG) laser capsulotomy can provoke persistent glaucoma, we examined the hypothesis that Nd:YAG laser capsulotomy may lead to a permanent elevation of IOP. In a case-control study, we compared two groups of 75 normotensive patients, who were unilaterally pseudophakic after phacoemulsification (PE) + PCL. Patients in group 1 had undergone Nd:YAG capsulotomy at least 2 months prior to this study, while in group 2 the posterior capsule was intact. Both groups were selected at random. Prior to surgery, none of the patients had suffered from glaucoma. Goldmann applanation tonometry was performed in both eyes of each patient and from that the ratio of IOP(pseudophakic)/IOP(phakic) was calculated. The distribution of this ratio for the two groups was compared using the Wilcoxon signed-rank test. There were 52 female and 23 male patients in group 1 versus 56 female and 19 male patients in group 2. Their mean ages were 75 + or -11 (group 1) and 75 + or - 9 years (group 2). The mean interval after PE + PCL was 48 + or - 29 months for patients with Nd:YAG capsulotomy and 16 + or - 17 months for patients with intact posterior capsule. Since the Nd:YAG capsulotomy, 28 + or - 23 months had elapsed on average. The median ratio of IOP (pseudophakic)/IOP(phakic) was higher in the Nd:YAG capsulotomy group than in the group of patients with an intact posterior capsule (1.00 vs. 0.80; p < 0.0001). There was almost no percentile, for which the distribution curve of group 1 intersected the curve of group 2. The median IOP in pseudophakic eyes was 14 mm Hg in group 1 and 12 mm Hg in group 2 (p<0.0001). These results are in accordance with the hypothesis that Nd:YAG capsulotomy will raise IOP permanently in most patients. Therefore Nd:YAG capsulotomy may harbor the risk of glaucomatous optic nerve damage in the long run. Long-term follow-up seems advisable in order to prevent possible glaucoma damage.

[Perioperative prevalence of epiretinal membranes in eyes with senile cataract]. / Perioperative Prävalenz von epiretinalen Membranen bei Augen mit seniler Katarakt.

BACKGROUND: Results from epidemiologic studies suggest that cataract extraction is a risk-factor for the formation of epiretinal membranes (EM). PATIENTS AND METHODS: 250 consecutive eyes which underwent uneventful phakoemulsification with implantation of a posterior chamber intraocular lens were examined within two weeks prior and an two weeks after surgery for the presence of epiretinal membranes. Cellophane macular reflex (CMR) was distinguished from macular pucker (MP). RESULTS: We found an increase in the prevalence of epiretinal membranes from preoperatively 12/250 (4.8%) to post-operatively 33/250 (13.2%). The prevalence of CMR increased from 8/250 (3.2%) to 27/250 (10.8%). The prevalence of MP remained almost the same 4/250 (1.6%) prior and 6/250 (2.4%) after surgery. CONCLUSIONS: Increased prevalence of epiretinal membranes following cataract extraction observed in epidemiological studies can be explained by easier detection of such membranes in pseudophakic eyes where the observer gets a clear view of the fundus. Therefore it is questionable whether uneventful extracapsular cataract extraction can induce the formation of epiretinal membranes.

Lipid composition of human aqueous humor.

The lipid composition of human aqueous humor was determined in ten samples from patients undergoing cataract surgery. The mean concentration was 16.4 mg/dl for total lipids, 2.5 for phospholipids, 1.1 for free fatty acids, 1.7 for unesterified cholesterol 2.0 for triglycerides, and 9.0 mg/dl for cholesterol esters, respectively. The presence of lipids in aqueous humor suggests that lipids are transported through the human aqueous humor.

Identification of metabolic risk factors for posterior subcapsular cataract.

To determine the possible role of glucose and lipid metabolism in the formation of cataract in elderly people we studied 463 patients undergoing cataract extraction. Of 188 males, 35 (19%) had posterior subcapsular cataract (group 1), 27 (14%) had cortical cataract (group 2), and 24 (13%) had nuclear cataract (group 3). Of 275 females, 27 (10%) belonged to group 1, 44 (16%) to group 2, and 33 (12%) to group 3. Patients in group 1 were significantly younger than those of group 2 and 3. In addition, patients in group 1 had higher concentrations of fasting serum triglycerides than patients of group 2 or 3. No difference in mean concentrations of serum cholesterol was observed between the different groups. However, fasting plasma glucose concentrations were higher in group 1 patients than in those of group 2 or 3. Patients in group 1 had a higher 'Broca index' than those in group 2 or 3, with the exception of males in group 3. These results suggest that the association of hypertriglyceridemia, hyperglycemia and obesity favors the formation of a specific morphologic type of lens opacity, posterior subcapsular cataract, occurring at an early age. They imply the possibility of effective modes of preventive therapy for a subgroup of patients with 'senile' cataract.

Increased prevalence of apolipoprotein E2 in patients with retinitis pigmentosa.

Apolipoprotein E isoforms were determined in 139 unrelated patients with retinitis pigmentosa (RP). When compared to prevalence rates for the general population in Germany, an increased prevalence was observed for phenotypes E2/E2: 10.1 vs. 1.0% (p less than 0.001), E2/E3: 19.4 vs. 12.0% (p less than 0.05), and E2/E4: 5.8 vs. 1.5% (n.s.), while the prevalence appeared to be reduced for phenotypes E3/E3: 48.9 vs. 59.8% (n.s.) E3/E4: 13.7 vs. 22.9% (p less than 0.05), and E4/E4: 2.2 vs. 2.8% (n.s.). These findings suggest that genetically determined abnormalities of plasma lipoprotein metabolism may be associated with some forms of RP.

Lipoprotein abnormalities in primary biliary cirrhosis. Association with hepatic lipase inhibition as well as altered cholesterol esterification.

The nature and etiology of plasma lipoprotein abnormalities in patients with varying stages of primary biliary cirrhosis (PBC) were assessed. Two distinct lipoprotein patterns were observed. In patients with early and intermediate histologic stages of PBC, mild elevations of very low density lipoproteins and low density lipoproteins (LDLs), and marked increases in high density lipoproteins (HDLs) were often noted (group 1). In contrast, patients with advanced disease had marked elevations in LDLs with the presence of lipoprotein-X, and a significant decrease in HDLs (group 2). The lipoprotein pattern in group 1 was characterized by a normal ratio of free cholesterol to total cholesterol, whereas in group 2, this ratio was elevated. In plasma from group 1 patients only spherical micelles were observed on electron microscopy, whereas in plasma from group 2 patients bilayered disks could be seen in LDLs and HDLs. The increase in HDLs observed in group 1 subjects was associated with elevations in HDL2, whereas in group 2 subjects only very low amounts of HDL3 were observed on analytic ultracentrifugation. Mean plasma apolipoprotein B and C-II concentrations were increased in both groups; but apolipoprotein A-I and AII values were divergent, with group 1 subjects having elevated values,and group 2 subjects having decreases values. Mean postheparin hepatic lipase activity was decreased in both groups of patients with PBC due to the presence of an inhibitor in PBC plasma, while altered cholesterol esterification was only observed in group 2. These data indicate that hepatic lipase inhibition may play an important role in the pathogenesis of the lipoprotein abnormalities seen in early and intermediate PBC, and these abnormalities are then further modified by altered cholesterol esterification in advanced disease.