[Vitreoretinal surgery in complicated retinal detachment in children and adolescents]

BACKGROUND

The purpose of this study was to evaluate anatomical and functional results of vitreoretinal silicone oil surgery for complicated retinal detachments due to trauma and myopia in children and juveniles.

METHODS

We retrospectively reviewed the records of children and juveniles up to 17 years of age who had undergone vitreoretinal surgery with silicone oil instillation for the above causes between 1990 and 1997. A total of 30 eyes of 29 patients were operated on, 24 because of trauma and the remaining 6 because of retinal detachment in high myopia. There was a mean postoperative follow-up period of 1.7 years. Silicone oil could be removed from 18 of the 30 eyes after a mean of 4.7 months. The median number of vitrectomies performed per eye was two (range one to five).

RESULTS

In 21 of 30 eyes (70%) the retina could be reattached after one or more surgeries. Silicone oil was removed from 16 of these 21 eyes (53%) which was defined as anatomical success. Visual acuity increased (14 eyes, 48.3%) or remained unchanged (9 eyes, 31%) in 23 of 29 eyes (79.3%). Visual acuity decreased in 6 of 29 eyes (20.7%) despite surgery. Two eyes (6.7%) had to be enucleated due to bulbar phthisis. Seventeen eyes reached a postoperative visual acuity of at least counting fingers. In one child functional tests could not be performed due to young age.

CONCLUSION

Vitreoretinal surgery with silicone oil endotamponade has become a standard procedure in treating complicated retinal pathologies in children and juveniles. In very young patients it is thought that silicone oil instillation has advantages over gas endotamponade since it is very difficult for children to keep the proper face-down positioning after the procedure. The retinal reattachment rate is encouraging. In the majority of cases visual acuity greater than or equal to counting fingers and thus orienting vision was reached postoperatively. In few cases even reading vision was regained.

T-cell apoptosis in situ in experimental autoimmune encephalomyelitis following methylprednisolone pulse therapy

The apoptosis-inducing effects of i.v. methylprednisolone were investigated as a possible method of controlling inflammation in the CNS in adoptive transfer-experimental autoimmune encephalomyelitis (AT-EAE) in Lewis rats. Two pulses of methylprednisolone were given at the peak of mild and of severe disease. T-cell apoptosis was assessed on spinal cord cross-sections by morphology and TUNEL staining. Concentrations of methylprednisolone were measured in serum, CSF and spinal cord tissue by high-pressure liquid chromatography (HPLC). In severe EAE, 10 mg/kg methylprednisolone increased T-cell apoptosis significantly and T-cell infiltration was marginally decreased. A maximal dose of 50 mg/kg methylprednisolone was superior in both respects and, in contrast to 10 mg/kg methylprednisolone, was also effective in mild EAE. A dose of 1 mg/kg methylprednisolone did not produce notable changes compared with controls treated with phosphate-buffered saline. Serum, CSF and spinal cord concentrations of methylprednisolone measured by HPLC 2 h after a single i.v. injection of 10 or 50 mg/kg methylprednisolone revealed significantly higher methylprednisolone concentrations in severe EAE compared with mild disease. With 50 mg/kg methylprednisolone, we obtained serum and CSF concentrations in the region of 10(-5) M methylprednisolone. We also studied the expression of bcl-2, a typical anti-apoptotic regulatory protein, in T cells, and found no change after methylprednisolone treatment compared with controls. Methylprednisolone did not induce apoptosis of oligodendrocytes, which would have been an unwanted side effect in CNS cells. This study provides evidence that methylprednisolone dose-dependently augments T-cell apoptosisin situ in AT-EAE. Our results may have implications for the use of glucocorticosteroids at very high doses in the treatment of inflammatory disorders of the CNS, such as multiple sclerosis, or of other target organs.

Sustained reduction of exercise perfusion defect extent and severity with isosorbide mononitrate (Imdur) as demonstrated by means of technetium 99m sestamibi

BACKGROUND

The impact of long-acting nitrates on the extent and severity of stress-induced myocardial ischemia is not well described, especially after long-term treatment.

METHODS

Forty patients with chronic stable angina and reversible ischemia on an exercise stress myocardial perfusion single photon emission computed tomography (ex-SPECT) were prospectively studied in a 6-week period. At baseline, rest thallium-201/exercise stress technetium 99m sestamibi SPECT was performed, followed by treatment with extended-release isosorbide 5-mononitrate (5-ISMN, Imdur). Follow-up ex-SPECT was performed 5 days and 6 weeks after the initiation of therapy with extended-release 5-ISMN. The exercise treadmill testing (ETT) protocol and exercise duration of the follow-up studies were the same as that of the baseline ETT. Defect extent and severity were analyzed both by means of an automated quantitative method, with CEqual software, and visually, with a 20-segment scoring system (which was also used to derive a summed stress score [SSS]).

RESULTS

In the 6-week study period, significant reductions occurred in both the extent and the severity of exercise-induced ischemia by means of quantitative SPECT (13.8% [P<.0003] and 12.7% [P<.0003], respectively). There was no significant change in these variables between stages 2 (day 5) and 3 (6 weeks), indicating no development of tolerance to the nitrate effect. Similar reductions were noted by means of the visual analysis (SSS reduction of 13.0% [P<.002]) in the entire study period.

CONCLUSIONS

Patients with chronic-stable-angina treated with a long-acting nitrate demonstrate improvement in myocardial perfusion defect extent and severity in an extended period by means of both visual and quantitative analysis of sequential exercise testing to the same rate-pressure product end point.

Effects of extremely low frequency electromagnetic field (EMF) on collagen type I mRNA expression and extracellular matrix synthesis of human osteoblastic cells

Human osteoblastic cells were grown in a three-dimensional (3-D) cell culture model and used to test the effects of a 20 Hz sinusoidal electromagnetic field (EMF; 6 mT and 113 mV/cm max) on collagen type I mRNA expression and extracellular matrix formation in comparison with the effects of growth factors. The cells were isolated from trabecular bone of a healthy individual (HO-197) and from a patient presenting with myositis ossificans (MO-192) and grown in a collagenous sponge-like substrate. Maximal enhancement of collagen type I expression after EMF treatment was 3.7-fold in HO-197 cells and 5.4-fold in MO-192 cells. Similar enhancement was found after transforming growth factor-beta (TGF-beta) and insulin-like growth factor-I (IGF-I) treatment. Combined treatment of the cells with EMF and the two growth factors TGF-beta and IGF-I did not act synergistically. MO-192 cells produced an osteoblast-characteristic extracellular matrix containing collagen type I, alkaline phosphatase, and osteocalcin, together with collagen type III, TP-1, and TP-3, two epitopes of an osteoblastic differentiation marker. The data suggest that the effects of EMFs on osteoblastic differentiation are comparable to those of TGF-beta and IGF-I. We conclude that EMF effects in the treatment of skeletal disorders and in orthopedic adjuvant therapy are mediated via enhancement of collagen type I mRNA expression, which may lead to extensive extracellular matrix synthesis.

FACKEL is a sterol C-14 reductase required for organized cell division and expansion in Arabidopsis embryogenesis

In flowering plants, the developing embryo consists of growing populations of cells whose fates are determined in a position-dependent manner to form the adult organism. Mutations in the FACKEL (FK) gene affect body organization of the Arabidopsis seedling. We report that FK is required for cell division and expansion and is involved in proper organization of the embryo. We isolated FK by positional cloning. Expression analysis in embryos revealed that FK mRNA becomes localized to meristematic zones. FK encodes a predicted integral membrane protein related to the vertebrate lamin B receptor and sterol reductases across species, including yeast sterol C-14 reductase ERG24. We provide functional evidence that FK encodes a sterol C-14 reductase by complementation of erg24. GC/MS analysis confirmed that fk mutations lead to accumulation of intermediates in the biosynthetic pathway preceding the C-14 reductase step. Although fk represents a sterol biosynthetic mutant, the phenotype was not rescued by feeding with brassinosteroids (BRs), the only plant sterol signaling molecules known so far. We propose that synthesis of sterol signals in addition to BRs is important in mediating regulated cell growth and organization during embryonic development. Our results indicate a novel role for sterols in the embryogenesis of plants.

FACKEL is a sterol C-14 reductase required for organized cell division and expansion in Arabidopsis embryogenesis

In flowering plants, the developing embryo consists of growing populations of cells whose fates are determined in a position-dependent manner to form the adult organism. Mutations in the FACKEL (FK) gene affect body organization of the Arabidopsis seedling. We report that FK is required for cell division and expansion and is involved in proper organization of the embryo. We isolated FK by positional cloning. Expression analysis in embryos revealed that FK mRNA becomes localized to meristematic zones. FK encodes a predicted integral membrane protein related to the vertebrate lamin B receptor and sterol reductases across species, including yeast sterol C-14 reductase ERG24. We provide functional evidence that FK encodes a sterol C-14 reductase by complementation of erg24. GC/MS analysis confirmed that fk mutations lead to accumulation of intermediates in the biosynthetic pathway preceding the C-14 reductase step. Although fk represents a sterol biosynthetic mutant, the phenotype was not rescued by feeding with brassinosteroids (BRs), the only plant sterol signaling molecules known so far. We propose that synthesis of sterol signals in addition to BRs is important in mediating regulated cell growth and organization during embryonic development. Our results indicate a novel role for sterols in the embryogenesis of plants.

FACKEL is a sterol C-14 reductase required for organized cell division and expansion in Arabidopsis embryogenesis

In flowering plants, the developing embryo consists of growing populations of cells whose fates are determined in a position-dependent manner to form the adult organism. Mutations in the FACKEL (FK) gene affect body organization of the Arabidopsis seedling. We report that FK is required for cell division and expansion and is involved in proper organization of the embryo. We isolated FK by positional cloning. Expression analysis in embryos revealed that FK mRNA becomes localized to meristematic zones. FK encodes a predicted integral membrane protein related to the vertebrate lamin B receptor and sterol reductases across species, including yeast sterol C-14 reductase ERG24. We provide functional evidence that FK encodes a sterol C-14 reductase by complementation of erg24. GC/MS analysis confirmed that fk mutations lead to accumulation of intermediates in the biosynthetic pathway preceding the C-14 reductase step. Although fk represents a sterol biosynthetic mutant, the phenotype was not rescued by feeding with brassinosteroids (BRs), the only plant sterol signaling molecules known so far. We propose that synthesis of sterol signals in addition to BRs is important in mediating regulated cell growth and organization during embryonic development. Our results indicate a novel role for sterols in the embryogenesis of plants.

[Abdominal catastrophes and limb arterial occlusions caused by acute aortic dissection. Experiences of a longitudinal population-based study of 28 years]

The authors pursue longitudinal studies since 1972 on a defined population of 106,000 relating to several questions of the aortic dissection. Till now, in 90 patients 93 cases of the aortic dissection were found. In seven patients, the aortic dissection was complicated with the clinical and pathological symptoms of surgical diseases. The vascular complications of the aortic dissection caused obstruction of coecomesenteric arteries with severe ischemic signs in four patients, obstruction of iliac arteries in two patients and the left sublavian artery in one another. In an additional patient with a chronic recurrent pancreatitis, the acute aortic dissection as an acute exacerbation of chronic pancreatitis was considered. It makes known in a short report of cases the clinicopathological features of vascular complications of the thoracoabdominal aortic dissections. Their pathomechanisms as well as the possibilities of their diagnosis and treatment are reviewing in detail.

Secondary products in mycorrhizal roots of tobacco and tomato

Colonization of the roots of various tobacco species and cultivars (Nicotiana glauca Grah., N. longiflora Cav., N. rustica L., N. tabacum L., N. tabacum L. cv. Samsun NN, N. sanderae hort. Sander ex Wats.) as well as tomato plants (Lycopersicon esculentum L. cv. Moneymaker) by the arbuscular mycorrhizal fungus Glomus intraradices Schenck and Smith resulted in the accumulation of several glycosylated C13 cyclohexenone derivatives. Eight derivatives were isolated from the mycorrhizal roots by preparative high performance liquid chromatography (HPLC) and spectroscopically identified (MS and NMR) as mono-, di- and triglucosides of 6-(9-hydroxybutyl)-1,1,5-trimethyl-4-cyclohexen-3-one and monoglucosides of 6-(9-hydroxybutyl)-1,5-dimethyl-4-cyclohexen-3-one-1-carboxylic acid and 6-(9-hydroxybutyl)-1,1-dimethyl-4-cyclohexen-3-one-5-carboxylic acid. In contrast to the induced cyclohexenone derivatives, accumulation of the coumarins scopoletin and its glucoside (scopolin) in roots of N. glauca Grah. and N. tabacum L. cv. Samsun NN, was markedly suppressed.

Betalains from Christmas cactus

The presence of 14 betalain pigments have been detected by their characteristic spectral properties in flower petals of Christmas cactus (Schlumbergera x buckleyi). Along with the known vulgaxanthin I, betalamic acid, betanin and phyllocactin (6'-O-malonylbetanin), the structure of a new phyllocactin-derived betacyanin was elucidated by various spectroscopic techniques and carbohydrate analyses as betanidin 5-O-(2'-O-beta-D-apiofuranosyl-6'-O-malonyl)-beta-D-glucopyranosid e. Among the more complex betacyanins occurring in trace amounts, the presence of a new diacylated betacyanin ¿betanidin 5-O-[(5"-O-E-feruloyl)-2'-O-beta-D- apiofuranosyl-6'-O-malonyl)]-beta-D-glucopyranoside¿ has been ascertained. Furthermore, the accumulation of betalains during flower development and their pattern in different organs of the flower has been examined.

Regulation of Fas and FasL expression on rat Schwann cells

Although the PNS belongs to the immune privileged sites, it can become a target of immune attacks by invading T cells, causing inflammation and destruction. Yet the PNS also has a protective potential by eliminating the inflammatory cells via apoptosis. In analogy with other immune-protected sites, participation of the apoptosis-inducing Fas/FasL molecules could play an important role. To assess the possible involvement of the Fas/FasL system in T-cell apoptosis in the PNS of the rat, we characterized Fas and FasL expression on neonatal rat Schwann cells (SC) in vitro. Cells were stimulated in vitro with interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), or a combination of both. We observed upregulation of FasL expression under the influence of IFN-gamma, while adding TNF-alpha alone to the culture medium had no effect. IFN-gamma and TNF-alpha acted synergistically, leading to an increased FasL expression that reached its maximum 70 h after cytokine exposure, as shown by FACS analysis, SDS-PAGE, and Western blot. Fas expression on untreated SC showed fluctuating levels, while addition of IFN-gamma and TNF-alpha suppressed Fas expression completely. These findings are in accord with recently published results showing Fas and FasL expression on malignant human cells, derived from brain tumors and upregulation of FasL on astrocytes after exposure to IFN-gamma and TNF-alpha. Furthermore, FasL-expressing SC could be revealed by immunostaining of sciatic nerve from Lewis rats suffering from experimental autoimmune neuritis (EAN). We suggest that Fas/FasL expression on SC may contribute to the elimination of invading autoreactive T cells in the PNS in concert with other immune defense mechanisms.

Transient N-acetylgalactosaminylation of mannosyl phosphate side chain in Paramecium primaurelia glycosylphosphatidylinositols

The surface antigens of the free-living protozoan Paramecium primaurelia belong to the family of glycosylphosphatidylinositol (GPtdIns)-anchored proteins. Using a cell-free system prepared from P. primaurelia, we have described the structure and biosynthetic pathway for GPtdIns glycolipids. The core glycans of the polar glycolipids are modified by a mannosyl phosphate side chain. The data suggest that the mannosyl phosphate side chain is added onto the core glycan in two steps. The first step involves the phosphorylation of the GPtdIns trimannosyl conserved core glycan via an ATP-dependent kinase, prior to the addition of the mannose linked to the phosphate group. We show that dolichol phosphate mannose is the donor of all mannose residues including the mannose linked to phosphate. Furthermore, we were able to identify in vitro a hydrophilic intermediate containing an additional N-acetylgalactosamine linked to the mannosyl phosphate side chain. The addition of this purified hydrophilic radiolabelled intermediate into the cell-free system leads to a loss of the GalNAc residue and its conversion to the penultimate intermediate having only mannosyl phosphate as a side chain. Together the data indicate that the GalNAc-containing intermediate is a transitional intermediate. We suggest that the GalNAc-containing intermediate is essential for biosynthesis and maturation of GPtdIns precursors. It is hypothesized that this oligosaccharide processing in the course of GPtdIns biosynthesis is required for the translocation of GPtdIns from the cytoplasmic side of the endoplasmic reticulum to the luminal side.

Pigment epithelium defects after submacular surgery for choroidal neovascularization: first results

It was the aim of this study to compare postoperative pigment epithelium defects after submacular surgery for well-defined choroidal neovascularization (CNV) with preoperative fluorescein angiogram (FAG), indocyanine green angiogram (ICG), and intraoperative findings of the excised neovacularization. Surgical removal of the CNV was videotaped. By means of a gauge the absolute size of an anatomic structure was determined which was visible on video, FAG, and ICG as well. Postoperatively another FAG was performed to further examine the funduscopically visible pigment epithelium defect. By comparison with the above-mentioned anatomic structure it was thus possible to determine the exact size of CNV and pigment epithelium defect. The extent of the pigment epithelium defect as determined on postoperative FAG after submacular surgery surpasses the size of CNV as measured in FAG, ICG, and anatomical preparation.

Epidemiology and clinicopathology of aortic dissection

STUDY OBJECTIVES

To determine the incidence and mortality as well as to analyze the clinical and pathologic changes of aortic dissection.

DESIGN AND SETTING

A population-based longitudinal study over 27 years on a study population of 106,500, including 66 hospitalized and 18 nonhospitalized consecutively observed patients.

MEASURES

Analysis of data from the medical, surgical, and autopsy records of patients with aortic dissection.

RESULTS

Altogether, 86 cases of aortic dissection were found in 84 patients, corresponding to a 2.9/100,000/yr incidence. Sixty-six of the 84 patients (79%) were admitted to the hospital, and 18 patients (21%) died before admission. Their ages ranged from 36 to 97 years, with a mean of 65. 7 years. The male/female ratio was 1.55 to 1. A total of 22.7% of the hospitalized patients died within the first 6 h, 33.3% within 12 h, 50% within 24 h, and 68.2% within the first 2 days after admission. Six patients were operated on, with a perioperative mortality of two of six patients and a 5-year survival of two of six patients. All patients who were not operated on died. Pain was the most frequent initial symptom. Every patient had some kind of cardiovascular and respiratory sign. Neurologic symptoms occurred in 28 of 66 patients (42%). Five patients presented with clinical pictures of acute abdomen and two with acute renal failure. Trunk arteries were affected in 33 of the 80 autopsied cases (41%), and rupture of aorta was seen in 69 cases (86%). In five cases, spontaneous healing of dissection was also found. The ratio of proximal/distal dissections was 5.1 to 1. All 18 prehospital cases were acute. Fifty-nine cases (89.4%) were acute at admission, and 7 cases (10.6%) were chronic dissections. Hypertension and advanced age were the major predisposing factors.

CONCLUSION

Aortic dissection was the initial clinical impression in only 13 of the 84 patients (15%). Thus, 85% of the patients did not receive immediate appropriate medical treatment. For this reason, these late-recognized and/or unrecognized cases may be regarded as an untreated or symptomatically treated group, whose course may resemble the natural course of aortic dissection.

Plasmapheresis combined with continuous venovenous hemofiltration in surgical patients with sepsis

OBJECTIVE

To examine the effect of continuous venovenous hemofiltration (CVVHF) combined with plasmapheresis (TPE) in critically ill surgical patients after treatment of the septic focus.

DESIGN

Observational pilot study.

SETTING

University teaching hospital intensive care unit.

INTERVENTIONS

TPE and CVVHF were administered 24 h after surgical and/or interventional treatment of septic focus. Arterial blood pressure, cardiac output, and systemic vascular resistance values were monitored. We examined the effect of the combined extracorporeal detoxification on outcome related to age, morbidity, organic failure rate, and initial APACHE II score.

MEASUREMENTS AND RESULTS

Forty-three patients with sepsis were treated; 19 received TPE in combination with CVVHF, and 24 did not receive extracorporeal therapy. Overall mortality was 44.2%. In the therapy group mortality was lower (42.1 vs. 45.8%), but the primary organic failure rate was higher. The relationship between mortality and age was similar in the two groups. There was also no difference between the groups in the course of scores on APACHE II, multiple-organ failure, and sepsis severity. Only patients with an initial APACHE II score of 21-25 had a significant reduction in mortality after combined extracorporeal detoxification. Mortality of 17% in TPE/CVVHF patients with single- (pulmonary) and double-organ failure (renal/pulmonary) was significantly lower (P < 0.0001) than in untreated patients.

CONCLUSIONS

Reduction in mortality in single- and double-organ failure was as high as 28% in septic patients with combined extracorporeal detoxification. A prospective randomized trial in sepsis and double-organ failure should be projected.

[Intraoperative electromyographic recurrent laryngeal nerve identification as a routine measure]

In recent years, two methods of intraoperative monitoring of the laryngeal nerve have mostly been used: evoked electromyographic responses via endscopically applied needle electrodes inserted into the adducting laryngeal muscles, and non-invasive electrodes like special tubes with integrated electrodes or separately insertable electrodes like the postcricoid electrode or disposable electrodes attached to the tube, as used in this study. The incidence of recurrent nerve paresis or paralysis during the IRM period was 1/174 nerves (0.6%). The advantage of the IRM is the quick and certain identification of the nerve; intraoperative monitoring cannot replace a proper surgical technique. We conclude that the IRM, using a laryngeal surface electrode attached to the tube, is a safe and reliable method.

Chalconoids from Fissistigma bracteolatum

Phytochemical studies on the leaves of Fissistigma bracteolatum yielded besides the two known compounds 2-hydroxy-3,4,6-trimethoxychalcone (1) and 5,7,8-trimethoxyflav-3-ene (2), five new chalconoids 2-hydroxy-3,4,6-trimethoxychalcene (3), 2-hydroxy-3,4,6-trimethoxydihydrochalcone (4), 2'-hydroxy-3',4',6'-trimethoxydihydrochalcone (5), 2'-hydroxy-3',4',6'-trimethoxy-beta'-methoxychalcane (6) and 2'-hydroxy-3',4',6'-trimethoxy-beta'-ethoxychalcane (7). The structures of these compounds were determined by mass and NMR spectroscopic methods.

Vascular structure and microcirculation of experimental pancreatic carcinoma in rats

OBJECTIVE

To study angiogenesis and microcirculation in experimental pancreatic carcinoma.

DESIGN

Open experimental study.

SETTING

2 University hospitals, Germany and USA.

ANIMALS

16 male Lewis rats.

INTERVENTIONS

Induction of a duct-like pancreatic cancer in the pancreas and peritoneum by interposition of fragments of tumour between 2 inert transparent polymethylmethacrylate plates.

MAIN OUTCOME MEASURES

Microcirculation in the tumour and interaction between leucocytes, tumour, and endothelium investigated by intravital microscopy.

RESULTS

The density of vessels in the carcinoma was significantly less than in normal pancreatic tissue (p = 0.0004). The vasculature of the tumour was characterised by a lack of differentiation in architecture of vessels, formation of sinusoidal and lacunar vessels and sudden changes in diameter of vessels. Red blood cell velocity differed among tumour vessels, but mean values were similar to those of normal exocrine pancreas. The mixed lymphocyte culture test indicated that the cell line DSL6A was immunogenic. However, high-affinity leucocyte-endothelium-interaction was significantly reduced in the tumour's microcirculation after both orthotopic and heterotopic implantation (p = 0.002). Rates of apoptosis were suppressed in heterotopic tumours compared with orthotopic ones. Tumour growth was faster in heterotopic tumours.

CONCLUSIONS

Experimental duct-like pancreatic carcinoma can be differentiated from normal pancreas by: chaotic arrangement of vessels with loss of differentiation of architecture and heterogeneous distribution; the formation of sinusoidal or lacunar vessels; lower vascular density with similar erythrocyte velocity; increase in mean diameter of vessels; reduced leucocyte-endothelium interaction despite confirmed immunogeneity independent of wall shear rates. The site of implantation influences apoptosis and growth rates.

Endothelin-1 induces interleukin-6 release via activation of the transcription factor NF-kappaB in human vascular smooth muscle cells

The potent vasoconstrictor peptide endothelin-1 (ET-1) has been implicated in the pathophysiology of atherosclerosis and its complications. Since inflammation of the vessel wall is a hallmark of atherosclerosis, the purpose of the present study was to investigate the influence of ET-1 on cytokine production in human vascular smooth muscle cells (SMC) as a marker of inflammatory cell activation. ET-1 (100 pM - 1 microM) stimulated interleukin-6 (IL-6) secretion from human vascular SMC in a concentration-dependent manner. The ET-A-receptor antagonist BQ-123 (10 microM), but not the ET-B-receptor antagonist BQ-788, inhibited IL-6 release. ET-1 also transiently increased IL-6 mRNA compatible with regulation of IL-6 release at the pretranslational level. Electrophoretic mobility shift assays demonstrated time- and concentration-dependent activation of the proinflammatory transcription factor nuclear factor-kappaB (NF-kappaB) in ET-1-stimulated human vascular SMC. A decoy oligodeoxynucleotide bearing the NF-kappaB binding site inhibited ET-1-stimulated IL-6 release to a great extent suggesting that this transcription factor plays a key role for cytokine production elicited by ET-1. Moreover, the antioxidant pyrrolidine dithiocarbamate (10 microM) inhibited ET-1-induced IL-6 release indicating involvement of reactive oxygen species in ET-1 signaling. ET-1-stimulated IL-6 secretion was also suppressed by diphenylene iodonium (40 microM), an inhibitor of flavon-containing enzymes such as NADH/NADPH oxidase. The results demonstrate the ability of ET-1 to induce an inflammatory response in human vascular SMC. These observations may contribute to a better understanding of the role of ET-1 in inflammatory activation of the vessel wall during atherogenesis.

Spectroscopy of individual light-harvesting 2 complexes of Rhodopseudomonas acidophila: diagonal disorder, intercomplex heterogeneity, spectral diffusion, and energy transfer in the B800 band

This paper reports a detailed spectroscopic study of the B800 absorption band of individual light-harvesting 2 (LH2) complexes of the photosynthetic purple bacterium Rhodopseudomonas acidophila at 1. 2 K. By applying single-molecule detection techniques to this system, details and properties can be revealed that remain obscured in conventional ensemble experiments. For instance, from fluorescence-excitation spectra of the individual complexes a more direct measure of the diagonal disorder could be obtained. Further spectral diffusion phenomena and homogeneous linewidths of individual bacteriochlorophyll a (BChl a) molecules are observed, revealing valuable information on excited-state dynamics. This work demonstrates that it is possible to obtain detailed spectral information on individual pigment-protein complexes, providing direct insight into their electronic structure and into the mechanisms underlying the highly efficient energy transfer processes in these systems.

Metabolic transformation of the brassinosteroid 24-epi-castasterone by the cockroach Periplaneta americana

After feeding of 24-epi-castasterone to the cockroach Periplaneta americana an organ-specific epimerization of the brassinosteroid to 2,24-diepi-castasterone could be detected in female insects. The metabolite being observed only in the ovaries and not in the testes of the insect was identified by GC/MS in comparison with a synthesized authentic sample. Contrary, 24-epi-brassinolide is not metabolized in the sexual organs of Periplaneta americana. This is the first evidence of a metabolic transformation of a brassinosteroid in insects.

Removal of UroLume endoprosthesis: experience of the North American Study Group for detrusor-sphincter dyssynergia application

PURPOSE

We present the experience of the North American UroLume Multicenter Study Group with removal of the UroLume endoprosthesis.

MATERIALS AND METHODS

A total of 160 neurologically impaired patients were enrolled in the North American UroLume Multicenter Study Group for detrusor external sphincter dyssynergia application. Analysis was performed in 2 groups of patients in which the device was removed during insertion and after implantation, respectively.

RESULTS

Device retrieval was required during insertion in 21 patients (13%) mainly due to misplacement or migration in 17. Extraction was done with minimal complications and in all but 2 cases subsequent UroLume implantation was successful. Of 158 men with the device in place 31 (19.6%) required removal. In 34 procedures 44 devices were removed, mainly due to migration. Time from implantation to removal ranged from 4 days to 66 months (mean 22 months). The UroLume was removed en bloc in 20 cases and in parts or wire by wire in 19. The majority of patients had no or minimal complications after extraction. Only 2 patients had serious temporary complications, including bleeding and urethral injury, with no lasting consequences. No malignancy developed as a result of UroLume insertion.

CONCLUSIONS

While there is a potential for urethral injury and bleeding, UroLume endoprosthesis removal is largely a simple procedure with minimal complications and consequences.