[Intraocular epithelial downgrowth - report on 14 cases from 1986 to 2000]. / Intraokulare Epithelimplantation - Bericht über 14 Patienten 1986 - 2000.

BACKGROUND: Diffuse and cystic epithelial downgrowth occur rarely, but they represent a mostly preventable potential cause of blindness as sequels to trauma and surgery. The aim of this study is to report on the etiology and course of disease in patients with histologically verified epithelial downgrowth. PATIENTS AND METHODS: From 1986 until 2000 the ophthalmopathological laboratory of the University Eye Hospital Hamburg-Eppendorf received 13 (4 external) referrals. Ten patients with cystic of diffuse intraocular epithelial downgrowth were treated and 9 eyes were operated on in the Hospital. RESULTS: At presentation 4/10 patients had a visual acuity of < or = 0.1, and 2/10 had no light perception. A cystic epithelial downgrowth was verified histologically in 9/13, and a diffuse form in 4/13 patients. Mucin production was proven histochemically in 1/9 intraocular epithelial downgrowth sections. In one case a spontaneous iris cyst was detected by the immunohistological examinations. Trauma (10/14) and surgery (3/14) were the most frequent causes and were symptomatic on average 17 years after the primary event. A curative surgery was done in 13/14 patients (5 x en bloc excision, 2 x penetrating keratoplasty, 1 x iridectomy, 2 x enucleations, 3 x external) resulting in no recurrences during the follow-up of 4(1/2) years (1 - 12 years). The postoperative visual acuity was ameliorated in 5/9, worsened in 2 patients, and 2 were enucleated. CONCLUSIONS: Epithelial downgrowth is a rare but preventable cause of blindness. The most important prophylaxis is meticulous primary surgery including a sufficient wound closure. The visual outcome depends on the preoperative conditions.

Complete arterial revascularisation in patients older than 70 years.

BACKGROUND: Coronary artery bypass grafting (CABG) using left internal thoracic artery and vein grafts is standard in patients of advanced age. A number of these patients, however, present without suitable vein grafting material and thus require the use of arterial conduits. In order to investigate the safety and efficacy of complete arterial revascularisation, we have compared the perioperative results of patients older than 70 years with conventional CABG and complete arterial revascularisation. PATIENTS AND METHODS: Group I (n = 172) with conventional CABG in 1999 was compared with 152 patients (group II) with complete arterial CABG between 1996 and July 2000. There were no significant differences regarding age, gender, left ventricular ejection fraction or incidence of three-vessel disease or left main stenosis. The proportion of reoperations was significantly higher in group II (16 %) vs. group I (4 %). RESULTS: A mean of 3.7 +/- 0.7 anastomoses (I) versus 4.0 +/- 0.9 (II) were performed per patient (p = n. s.). Mean operating time (I: 210 +/- 46 min; II: 194 +/- 46 min) and bypass time (I: 87 +/- 25 min; II: 78 +/- 29 min) were significantly lower in group II. Ischemic time (I: 46 +/- 22 min; II: 49 +/- 21 min) was not significantly different. The incidence of sternal dehiscence was 2.9 % (I: n = 5) vs. 1.3 % (II: n = 2). Hospital mortality was 4.6 % in group I vs. 3.9 % (II). CONCLUSION: Complete arterial revascularisation is a safe option in patients aged over 70. It remains to be shown whether it may also have advantage in the long term.

Enantioselective oxidative coupling of the titanium enolate of 3-phenylacetyl-2-oxazolidinone.

Enantioselective oxidative coupling of titanium and ytterbium enolates of 1 bound to chiral diol, e.g., TADDOL 6, and bisoxazoline ligands with ferrocenium cation as oxidant affords dimers 2 with moderate to good enantioselectivities. Reaction: see text.

8-N(3)-3'-biotinyl-ATP, a novel monofunctional reagent: differences in the F(1)- and V(1)-ATPases by means of the ATP analogue.

A novel photoaffinity label, 8-N(3)-3'-biotinyl-ATP, has been synthesized. The introduction of an additional biotin residue is advantageous for easy detection of labeled proteins. This could be first tested by reaction with the F(1)-ATPase from the thermophilic bacterium PS3 (TF(1)). UV irradiation of TF(1) in the presence of 8-N(3)-3'-biotinyl-ATP results in a nucleotide-dependent binding of the analogue in the noncatalytic alpha and the catalytic beta subunits of TF(1), demonstrating the suitability of this analogue as a potential photoaffinity label. Reaction with the V(1)-ATPase, however, led to labeling of subunit E, which has been suggested as a structural and functional homologue of the gamma subunit of the F-ATPases. MALDI-TOF mass spectrometry has been used to map the regions of subunit E involved in the binding of 8-N(3)-3'-biotinyl-ATP.

Isolation and characterization of a mouse monoclonal antibody against human corneal endothelial cells.

In vitro cultivation of human corneal endothelial cells (HCEC) is associated with loss of typical cobblestone-like appearance during successive passages. Thus far morphology was the sole criterion for the cell's endothelial nature. Mouse monoclonal antibodies (mabs) to human corneal endothelial cells were raised using standard immunization and hybridoma isolation procedures. The specificity of mabs for human corneal endothelial cells was tested in comparison to other endothelial cell types, to fibroblasts, corneal keratocytes and to human retinal pigmented epithelial cells. In addition immunofluorescence or immunoperoxidase staining was performed with frozen tissue sections of human corneas and with various other human tissues. The mab 9.3.E reacts with cultured human corneal endothelial cells, but not with cultured human fibroblasts and human keratocytes. In frozen sections selective positivity of corneal endothelium in contrast to negativity of the other corneal cell types was confirmed. In investigated extraocular tissues positivity was observed in smooth muscle cells including related cells (i.e. Ito and mesangial cells) and in Schwann's cells and adipocytes, but apparently not in vascular endothelial cells. The mab is human-specific and binds to a protein with a molecular weight of 130 kDa mainly accumulating along cell membranes. A mouse monoclonal antibody against human corneal endothelial cells was established in vitro and was shown to be capable of differentiating corneal endothelial cells from other corneal cell types, especially from corneal keratocytes. It is, however, not cornea-specific, but also reacts with certain extraocular cell types.

Photoaffinity labeling and photoaffinity cross-linking of phosphofructokinase-1 from Saccharomyces cerevisiae by 8-azidoadeninenucleotides.

Phosphofructokinase-1 from Saccharomyces cerevisiae is composed of four alpha- and four beta-subunits, each of them carrying catalytic and regulatory bindings sites for MgATP. In this paper, various photoaffinity labels, such as 8-azidoadenosine 5'-triphosphate, 8-azido-1,N6-ethenoadenosine 5'-triphosphate, and 8-N3-3'(2')-O-biotinyl-8-azidoadenosine 5'-triphosphate have been used to study their interaction with the enzyme in the dark and during irradiation. All nucleotidetriphosphates function as phosphate donor forming fructose 1,6-bisphosphate from fructose 6-phosphate. However, the kinetic analysis revealed distinctly differences between them. Photolabeling causes a decrease in enzyme activity to a similar extent, and ATP acts as competitive effector to inactivation. Three bifunctional diazidodiadeninedinucleotides (8-diN3AP4A, monoepsilon-8-diN3AP4A, and diepsilon-8-diN3AP4A) were applied for studying the spatial arrangement of the nucleotide binding sites. No cross-linking of the subunits was obtained by irradiation of the enzyme with 8-diN3AP4A. Photolabeling with diepsilon-8-diN3AP4A resulted in the formation of two alpha-beta cross-links with different mobilities in the SDS-polyacrylamide gel electrophoresis, while monoepsilon-8-diN3AP4A yielded only one alpha-beta cross-link. Because an interfacial location of the catalytic sites between two subunits is less likely, we suggest that the formation of cross-linked subunits may be the result of specific interactions of the bifunctional photolabels with regulatory sites at the interface of both subunits.

In human and rat lung membranes [35S]GTPgammaS binding is a tool for pharmacological characterization of G protein-coupled dinucleotide receptors.

The P2Y receptor family is activated by extracellular nucleotides such as ATP and UTP. P2Y receptors regulate physiological functions in numerous cell types. In lung, the P2Y2 receptor subtype plays a role in controlling Cl- and fluid transport. Besides ATP or UTP, also diadenosine tetraphosphate (Ap4A), a stable nucleotide, seems to be of physiological importance. In membrane preparations from human and rat lung we applied several diadenosine polyphosphates to investigate whether they act as agonists for G protein-coupled receptors. We assessed this by determining the stimulation of [35S]GTPgammaS binding. Stimulation of [35S]GTPgammaS binding to G proteins has already been successfully applied to elucidate agonist binding to various G protein-coupled receptors. Ap(n)A (n = 2 to 6) enhanced [35S]GTPgammaS binding similarly in human and rat lung membranes, an indication of the existence of G protein-coupled receptor binding sites specific for diadenosine polyphosphates. Moreover, in both human and rat lung membranes comparable pharmacological properties were found for a diadenosine polyphosphate ([3H]Ap4A) binding site. The affinity for Ap2A, Ap3A, Ap4A, Ap5A, and Ap6A was also comparable. 8-Diazido-Ap4A and ATP were less potent, whereas the pyrimidine nucleotide UTP showed hardly any affinity. Thus, we present evidence that different diadenosine polyphosphates bind to a common G protein-coupled receptor binding site in membranes derived either from human or rat lung.

[Removal of a cochlea implant with chronic granulation labyrinthitis and foreign body reaction]. / Explantation eines Cochlea-Implantats bei chronisch granulierender Labyrinthitis mit Fremdkörperreaktion.

BACKGROUND: Cochlea Implantation is an accepted treatment for children and adults with profound sensorineural deafness. In rare cases postoperative complications may occur so that removal of the implant is unavoidable. CASE REPORT: In a particular case we present and discuss the case of a 69-year-old patient. CONCLUSION: After removal of a cochlear implant, the electronic array is frequently left in the cochlea as a temporary replacement. This is a common practice, but whether it is advisable should be verified according to the specific intraoperative situation.

Cloning sulfur assimilation genes of Brassica juncea L.: cadmium differentially affects the expression of a putative low-affinity sulfate transporter and isoforms of ATP sulfurylase and APS reductase.

The heavy-metal accumulator Brassica juncea L. is a high-biomass crop able to extract heavy-metal ions from the soil, a substantial part being translocated from root to shoot. Previous work has shown that Cd accumulation is accompanied by massive formation of phytochelatins (PCs). Rapid de novo synthesis of PCs in roots and leaves requires an increased synthesis of the tripeptide glutathione (GSH), which in turn depends on increased sulfur assimilation. Therefore. we have cloned cDNAs for three enzymes involved in sulfur assimilation, i.e. a putative low-affinity sulfate transporter (LAST) and two isoforms each for ATP sulfurylase (ATPS) and APS reductase (APSR). As degradation of glucosinolates might provide an additional sulfur source under stress, we also cloned a myrosinase (MYR). RNA blot analysis of transcript amounts indicated that upon Cd exposure (25 microM) the expression of ATPS and APSR in roots and leaves of 6-week-old Brassica juncea plants was strongly increased, whereas the expression of MYR was unaffected. LAST transcripts were significantly reduced in the root but remained unchanged in the leaves. Concomitant with Cd induction of ATPS and APSR mRNAs, cysteine concentrations in roots and leaves increased by 81% and 25%, respectively, whereas GSH concentrations decreased in roots and leaves by 39% and 48%, respectively. In agreement with our previous report on Cd induction of gamma-glutamylcysteine synthetase in B. juncea, the results indicate coordinate changes of expression for several sulfur assimilation enzymes in response to an increased demand for cysteine during PC synthesis.

cDNA cloning and expression analysis of genes encoding GSH synthesis in roots of the heavy-metal accumulator Brassica juncea L.: evidence for Cd-induction of a putative mitochondrial gamma-glutamylcysteine synthetase isoform.

In roots of Brassica juncea L. cadmium (Cd) exposure (25 microM) induces a massive formation of phytochelatins (PCs), which is accompanied by an only moderate decrease (-20%) of the putative PC precursor glutathione (GSH). As PC formation in roots could be the result of local GSH de novo synthesis and/or depend on GSH import from the shoot, we have analyzed the expression of the enzymes involved in GSH synthesis in the root, namely OAS(thiol)lyase (OAS-TL; catalysing the last step in Cys biosynthesis), gamma-glutamylcysteine synthetase (gamma-ECS), and glutathione synthetase (GSHS). cDNA clones were isolated from a cDNA library prepared from heavy metal exposed roots. Protein sequences from cDNA clones encoding OAS-TL, gamma-ECS, and GSHS, all exhibited putative mitochondrial targeting sequences, however, for OAS-TL also two putative cytosolic isoforms were isolated. Furthermore, we have cloned several metallothionein cDNAs of the MT2 group. Northern blot analysis with coding region probes revealed that in roots of Cd-exposed plants transcript amounts for OAS-TL and GSHS were only moderately increased, whereas gamma-ECS mRNA showed a stronger increase. Expression analysis with 3'-UTR probes indicated that among the putative mitochondrial OAS-TL, gamma-ECS and GSHS isoforms only gamma-ECS was up-regulated in response to Cd exposure. Conversely, transcripts for MT2 appeared to be slightly reduced. The results indicate that in roots Cd-induced PC synthesis correlates with a moderate increase of expression of genes involved in GSH synthesis, the change for gamma-ECS being most pronounced.

The low-affinity ATP binding site of the Escherichia coli SecA dimer is localized at the subunit interface.

The homodimeric SecA protein is the ATP-dependent force generator in the Escherichia coli precursor protein translocation cascade. SecA contains two essential nucleotide binding sites (NBSs), i.e., NBS1 and NBS2 that bind ATP with high and low affinity, respectively. The photoactivatable bifunctional cross-linking agent 3'-arylazido-8-azidoadenosine 5'-triphosphate (diN3ATP) was used to investigate the spatial arrangement of the nucleotide binding sites of SecA. DiN3ATP is an authentic ATP analogue as it supports SecA-dependent precursor protein translocation and translocation ATPase. UV-induced photo-cross-linking of the diN3ATP-bound SecA results in the formation of stable dimeric species of SecA. D209N SecA, a mutant unable to bind nucleotides at NBS1, was also photo-cross-linked by diN3ATP, whereas no cross-linking occurred with the NBS2 mutant R509K SecA. We concluded that the low-affinity NBS2, which is located in the carboxyl-terminal half of SecA, is the site of crosslinking and that NBS2 binds nucleotides at or near the subunit interface of the SecA dimer.

Infarct size measurement by triphenyltetrazolium chloride staining versus in vivo injection of propidium iodide.

Infarct size delineation by triphenyltetrazolium chloride (TTC) staining is dependent on sufficient reperfusion. We therefore evaluated the possibility of using propidium iodide (PI), a reagent conventionally used in flow cytometry to fluorescently stain dead cells, for infarct size analysis after short periods of reperfusion. Forty-five rabbits were subjected to either 15 min, 2 h or 4.5 h of coronary artery occlusion without reperfusion, or to 15 min, 30 min and 2 h of coronary artery occlusion followed by 30 min, 1 h and 3 h of reperfusion. Fifteen min before terminating the experiment, PI was injected into the left atrium. Patent blue violet was used to delineate the area at risk. Following incubation in TTC, the area at risk was excised and cross sections obtained for microscopical infarct size quantification by PI fluorescence. PI fluorescence was absent after permanent occlusion and in control areas. Infarct sizes measured by TTC staining were significantly smaller after 1 h of reperfusion as compared to 3 h of reperfusion (30 min occlusion: 1+/-1 v 34+/-9%; P<0.05; 2 h occlusion: 9+/-6 v 47+/-8%; P<0.01). In contrast, infarct sizes determined by PI fluorescence reached values comparable to those measured by TTC staining or conventional histology after longer times of reperfusion already after 30 min of reperfusion (30 min occlusion: 35+/-16.5%; 2 h of occlusion: 61+/-8%). Therefore, after short times of reperfusion infarct size measurement by PI fluorescence is more reliable than by TTC staining.

Biotransformation of linoleic acid with the Candida tropicalis M25 mutant.

Linoleic acid was transformed by mutant Candida tropicalis M25 and transformations were studied in batch and fed-batch cultures. Cofermentations with palmitic acid as inducer of the fatty acid degradation pathway were performed. Besides the (Z),(Z)-octadeca-6,9-dienedioic acid, (Z),(Z)-3-hydroxyoctadeca-9,12-dienedioic acid and (Z),(Z)-3-hydroxytetradeca-5,8-dienedioic acid were obtained as the main fermentation products. The maximum concentrations of (Z),(Z)-octadeca-6,9-dienedioic acid and (Z),(Z)-3-hydroxyoctadeca-9,12-dienedioic acid reached values of 6.4 g/l and 6.9 g/l respectively. The structures of the products were characterized by chemical and spectroscopic methods. The configuration of the double bonds was not changed during bioconversion. As only one regioisomer of the hydroxylated fatty acid was detected, the hydroxylation is site-specific.

In seedlings of the heavy metal accumulator Brassica juncea Cu2+ differentially affects transcript amounts for gamma-glutamylcysteine synthetase (gamma-ECS) and metallothionein (MT2).

Glutathione (GSH) is the precursor of the phytochelatins (PC), which in plants and fungi are involved in heavy metal sequestration. The regulatory enzyme gamma-glutamylcysteine synthetase (gamma-ECS) catalyzes the first step in GSH biosynthesis. For the heavy metal accumulator Brassica juncea L. a partial gamma-ECS cDNA was cloned by RT-PCR. Treatment of suspension-cultured dark grown seedlings with micromolar concentrations of CuSO4 resulted in a strong increase of gamma-ECS mRNA in roots and shoots, concomitant with an increase of GSH and phytochelatins. A significant up-regulation of gamma-ECS mRNA was observed at 25 microM CuSO4 (shoot growth: -11%), whereas maximum up-regulation was obtained at 100 microM CuSO4 (shoot growth: -60%). Unexpectedly, metallothionein 2 (MT2) mRNA was decreased in response to the CuSO4 treatments. CdSO4 at a concentration of 50 microM caused a 72% reduction in shoot growth without affecting the amounts of gamma-ECS- and MT2 mRNAs. ZnSO4 at a concentration of 500 microM did not reduce growth but induced transient increases of gamma-ECS- and MT2 mRNAs. The implications of the results with respect to differential regulation of gamma-ECS and MT2 during heavy metal exposure are discussed.

Influence of the terminal complement-complex on reperfusion injury, no-reflow and arrhythmias: a comparison between C6-competent and C6-deficient rabbits.

OBJECTIVE: The complement system has been suggested to play a role in reperfusion injury which may result from an enhanced destruction of myocardial tissue or from an impairment of reflow. We investigated the influence of the C5b-9 complement complex on infarct size, reflow and arrhythmogenesis. METHODS: Twenty-eight C6-competent rabbits and 18 rabbits with congenital C6 deficiency were subjected to either 30 min or 2 h of coronary artery occlusion followed by reperfusion. C6 deficiency was confirmed by the complement titration test and immunohistology. The triphenyl tetrazolium chloride method was used to delineate infarct size. Reflow into infarcted areas was evaluated histologically after an in vivo injection of propidium iodide which served as an early fluorescence microscopic marker of damaged myocardium subjected to reflow. Continuous ECG monitoring allowed the recording of arrhythmias. RESULTS: After 30 min of coronary artery occlusion infarct size was significantly smaller in C6-deficient rabbits (5.0 +/- 2% of the risk region) as compared to C6-competent rabbits (28.4 +/- 8.5%, P = 0.0371). The extent of reflow into damaged myocardium was nearly the same in both animal groups at this time (38 +/- 9 vs. 39 +/- 7% of the risk region). After 2 h of coronary artery occlusion, infarct size was not different between both animal groups, but the extent of reflow into damaged myocardium was significantly smaller in C6-competent rabbits than in C6-deficient rabbits (25 +/- 4 vs. 40 +/- 4%; P = 0.0185). Two of the 18 C6-deficient rabbits had ventricular arrhythmias (Lown II-IV), none of which was fatal. Eleven of the 28 C6-competent animals had major ventricular arrhythmias which were fatal in 6 rabbits. CONCLUSIONS: These results suggest that the lytic C5b-9 complement complex leads to reperfusion injury in the early phase (30 min) of ischaemia, resulting in a larger infarct. After 2 h of ischaemia, complement activation enhances the no-reflow phenomenon but does not affect infarct size. Finally, the C6 status seems to influence the susceptibility to ventricular arrhythmias after coronary artery occlusion, independent of reperfusion.

[Disseminated lipogranulomatosis (Farber disease) with hydrops fetalis]. / Disseminierte Lipogranulomatose (M. Farber) mit Hydrops fetalis.

We report on a female preterm infant of 29 weeks' gestation with severe hydrops fetalis who died 3 days post natum as a result of disseminated intravascular coagulation. Autopsy findings included anasarca, bilateral pleural effusions, ascites and hepatosplenomegaly as well as multiple, up to pinhead sized, white granulomas on the surface of liver, spleen and lungs. Microscopy revealed storage macrophages of the reticuloendothelial system, especially in liver, spleen and bone marrow, the lymphatic organs, the salivary glands, the thyroid gland and the suprarenal medulla. Cerebrum, heart, kidneys, intestines and placenta were not afflicted. Atrophy of the lymphatic compartments in the spleen, lymph nodes and thymus, as well as disorder of the liver texture, are presumably a secondary result. The diagnosis of Farber's disease was established biochemically by the demonstration of ceramide depositions in the spleen, and in fibroblast cultures in situ by the accumulation of ceramide released from loaded radioactive glucosylceramide. Ultrastructurally, corresponding storage lysosomes were found in macrophages. To our knowledge this is the first account of Farber's disease in a preterm infant with hydrops fetalis.

Photoaffinity labeling and photoaffinity crosslinking of enzymes.

Photoaffinity labeling is a special type of chemical modification, where the label is activated by the action of light. This article presents the general principles and limitations of this technique, its application to the study of Micrococcus luteus ATPase and the use of photoaffinity crosslinking to probe the structure of this enzyme.

Photoaffinity labeling and photoaffinity crosslinking of enzymes

Photoaffinity labeling is a special type of chemical modification, where the label is activated by the action of light. This article presents the general principles and limitations of this technique, its application to the study of Micrococcus luteus ATPase and the use of photoaffinity crosslinking to probe the structure of this enzyme