[Twenty years of experience with bariatric surgery in a general hospital]. / Entwicklung der Adipositaschirurgie am Krankenhaus der Maximalversorgung: Uber 20 Jahre Behandlungserfahrung.

BACKGROUND: Bariatric surgery has been performed since 1983 at the Bad Cannstatt Hospital near Stuttgart, Germany. The aim of this study was to investigate the development of bariatric surgery during the past 25 years. METHODS: Data were collected retrospectively. The parameters were number of surgical procedures, hospital stay, and postoperative complications. RESULTS: In the 25-year period 1,041 primary bariatric operations were performed. Open horizontal bypass and open vertical banded gastroplasty were performed initially. Starting in 2003 there was a change to laparoscopic procedures (gastric banding and Roux-en-Y bypass). The mean hospital stays were 14.7+/-5.1 days for open procedures and 6.7+/-4.2 days for laparoscopic methods, with 30-day mortalities of 0.8% and 0.0% and short-term complications at 16.9% and 7.8%, respectively. CONCLUSIONS: Perioperative complications and hospital stay were reduced by performing laparoscopic bariatric surgery. Our study emphasizes the advantages of the laparoscopic procedures which are standard at our hospital and fit in with the remaining operations in a department of visceral surgery.

[Ultrasonic scissors. New vs resterilized instruments]. / Ultraschallscheren. Neue vs. resterilisierte Einmalinstrumente.

BACKGROUND: The aim of this study was to compare reliability in handling and function of resterilized and single-use disposable ultrasonic scissors. METHODS: In a prospective randomized study, the surgeon blindly tested new and resterilized ultrasonographic scissors. The parameters were force of activation, cutting effect, coagulation effect, error messages, and disturbing generator noise. RESULTS: Fifty-one new and 49 resterilized instruments in 94 operations were evaluated. The differences in force of activation, cutting effect, and coagulation were not significant. Error messages and disturbing noises were rare in both groups. Six new instruments and two resterilized instruments had to be exchanged because of problems during surgery. CONCLUSION: This study demonstrates comparable reliability in function and handling of resterilized and new ultrasonic scissors. The use of resterilized instruments leads to distinctly reduced costs and could contribute to efficiency in laparoscopic surgery.

Ultrasound scissors: new single-use instruments vs. resterilised single-use instruments - a prospective randomised study.

BACKGROUND: The aim of this study was to compare reliability in handling and function of resterilised and single-use disposable ultrasonic scissors. METHODS: In a prospective randomized study, the surgeon blindly tested new and resterilised ultrasonic scissors. The parameters were force of activation, cutting effect, coagulation effect, error messages and disturbing generator noise. RESULTS: 51 new and 49 resterilised instruments in 94 operations were evaluated. The differences in force of activation, cutting effect and coagulation were not significant. Error messages and disturbing noises were rare in both groups. 6 new instruments and 2 resterilised instruments had to be exchanged because of problems during surgery. CONCLUSION: This study demonstrates comparable reliability in function and handling of resterilised and new ultrasonic scissors. The use of resterilised instruments leads to distinctly reduced costs and could contribute to efficiency in laparoscopic surgery.

Retinal degeneration in the rd mouse in the absence of c-fos.

PURPOSE: Apoptosis is the final common death pathway of photoreceptors in light-induced retinal degeneration and in several animal models for retinal dystrophy. To date, little is known about gene regulation of apoptosis in the retina. The expression of the immediate early gene c-fos is upregulated concomitant with apoptosis in light-induced photoreceptor degeneration and in the rd mouse, an animal model for inherited retinal degeneration. In a recent study it was shown that c-Fos is essential for light-induced apoptosis of photoreceptors in vivo. To determine whether c-Fos is also involved in the apoptotic pathway of inherited retinal degeneration, rd/rd, c-fos -/- double-mutant mice have been generated. METHODS: Double-mutant mice (rd/rd, c-fos -/-) were crossbred from c-fos+/- mice and rd/rd mice. Their genotype was determined by polymerase chain reaction analysis of genomic DNA. Wild-type control mice and homozygous rd mice were killed at 2-day intervals from postnatal day (P)9 through P21. Double-mutant mice were killed at postnatal days P9, P11, P13, P15, and P21. To determine levels of apoptosis in the retina, eyes were enucleated and processed for light microscopy and in situ nick-end labeling. Total retinal DNA was extracted from isolated retinas for DNA fragmentation analysis. RESULTS: Morphologic, histochemical, and biochemical analyses showed that the time course of apoptosis and the outcome of photoreceptor degeneration in rd/rd, c-fos-/- double-mutant mice was indistinguishable from that in rd mice carrying functional c-fos. CONCLUSIONS: These data suggest that in contrast to its role in light-induced photoreceptor degeneration, c-Fos is not essential for apoptosis in the rd mouse.

[HPETE, an arachidonic acid metabolite, induces apoptosis in rat retina in vitro]. / HPETE, ein Arachidonsäure-Metabolit, induziert Apoptose in der Rattennetzhaut in vitro.

BACKGROUND: Apoptosis is a gene-regulated mode of cell death which gains increasing importance in retinal pathologies such as retinitis pigmentosa, retinal detachment and proliferative vitreoretinopathy. A better understanding of the regulation of apoptosis could imply the means to reduce photoreceptor cell death and thereby provide therapeutic strategies to influence the time course of retinal diseases. Previous studies in our laboratory demonstrated that light induces apoptosis in the rat retina in vivo as a function of light dose. In several cell systems, oxidative stress including oxygenated metabolites of arachidonic acid (AA) was found to evoke apoptosis. We have observed a light-elicited release of AA and the subsequent formation of its metabolites in the rat retina. Therefore, AA and its metabolites appeared to be suitable candidates for the induction of apoptosis during light exposure. MATERIALS AND METHODS: Isolated rat retinas were incubated for 60, 120 and 180 min, respectively, with and without the addition of 30 mumol 5S-hydroperoxyeicosatetraenoic acid (5-HPETE). Retinas were then processed for light- and electron microscopy and examined for the morphological signs of apoptosis. The rate of apoptosis in the outer nuclear layer was assessed quantitatively. RESULTS: 5S-HPETE induces apoptosis of photoreceptors in the rat retina in vitro. Quantitative analysis revealed a significant increase in the rate of apoptosis of 5S-HPETE-treated retinas when compared to untreated controls. CONCLUSION: Arachidonic acid metabolites released upon light exposure may represent messenger candidates for apoptosis in the retina.

Light-induced apoptosis: differential timing in the retina and pigment epithelium.

Apoptosis is a genetically regulated form of cell death. Individual cells show condensed nuclear chromatin and cytoplasm, and biochemical analysis reveals fragmentation of the DNA. Ensuing cellular components, apoptotic bodies, are removed by macrophages or neighboring cells. Genes involved in the regulation of apoptosis as well as stimuli and signal transduction systems, are only beginning to be understood in the retina. Therefore, we developed a new in vivo model system for the investigation of events leading to apoptosis in the retina and the pigment epithelium. We induced apoptosis in retinal photoreceptors and the pigment epithelium of albino rats by exposure to 3000 lux of diffuse, cool white fluorescent light for short time periods of up to 120 minutes. Animals were killed at different time intervals during and after light exposure. The eyes were enucleated and the lower central retina was processed for light- and electron microscopy. DNA fragmentation was analysed in situ by TdT-mediated dUTP nick-end labeling (TUNEL) or by gel electrophoresis of total retinal DNA. We observed that the timing of apoptosis in the photoreceptors and pigment epithelium was remarkably different, the pigment epithelium showing a distinct delay of several hours before the onset of apoptosis. In photoreceptors, apoptosis was induced within 90 minutes of light exposure, with the morphological appearance of apoptosis preceding the fragmentation of DNA. In the pigment epithelium, the morphological appearance of apoptosis and DNA fragmentation were coincident. Different regulative mechanisms may lead to apoptotic cell death in the retinal photoreceptors and pigment epithelium. This in vivo model system will allow measurement of dose-responses, a potential spectral dependence and the molecular background of apoptotic mechanisms in the retina.

The absence of c-fos prevents light-induced apoptotic cell death of photoreceptors in retinal degeneration in vivo.

Apoptotic cell death in the retina was recently demonstrated in animal models of the hereditary human retinal dystrophy known as retinitis pigmentosa. Although recent evidence indicates that the proto-oncogene c-fos is a mediator of apoptosis, its precise role is unclear. In fact, under some conditions, c-fos may even protect against apoptotic cell death. In the retina, c-fos is physiologically expressed in a diurnal manner and is inducible by light. We previously observed a light-elicited, dose-dependent apoptotic response in rat photoreceptors. To determine whether c-fos is involved in the light-induced apoptotic pathway we have used control mice and mice lacking c-fos. We found that following dark adaptation and two hours of light exposure both groups of animals exhibited only a few apoptotic cells. However, at 12 and 24 additional hours after light exposure, apoptosis increased dramatically in controls but was virtually absent in those mice lacking c-fos. Therefore, c-fos is essential for light-induced apoptosis of photoreceptors. Notably, c-fos is continuously upregulated concomitant with apoptotic photoreceptor death in our system and in animal models of retinitis pigmentosa (Agarwal, N. et al., Invest. Ophthalmol. Vis.Sci. Suppl. 36, S638 and Rich, K.A. et al., Invest. Ophthalmol. Vis. Sci. Suppl. 35, 1833). Inhibition of c-fos expression might therefore represent a novel therapeutic strategy to retard the time course of retinal dystrophies and light-induced retinal degeneration.

Lipofuscin in the retina: quantitative assay for an unprecedented autofluorescent compound (pyridinium bis-retinoid, A2-E) of ocular age pigment.

The pyridinium bis-retinoid, A2-E, has been discovered as one of the major autofluorescent components of retinal pigment epithelial lipofuscin. Due to its chemical characteristics, A2-E may contribute to cellular and molecular changes leading to age-related macular degeneration. Because A2-E is the first lipofuscin component that has been identified, purified, and its structure analysed, it represents an important marker molecule for studying lipofuscin formation under various conditions. In order to investigate the role of A2-E in ageing processes of the retinal pigment epithelium, we developed an HPLC assay for this compound using single wavelength UV-absorbance detection with continuous light emission. Standard A2-E was synthetized and purified by sequential TLC. In our assay, A2-E can be detected in amounts lower than 10 pmol. The assay has been applied to quantitative determination of A2-E amounts in albino rat eyes of different age groups. Our results demonstrate that there is a marked increase of A2-E levels in older animals. The method described is the first to allow quantification of this unusual retinoid from small amounts of biological samples.

Light damage in the rat retina: glial fibrillary acidic protein accumulates in Müller cells in correlation with photoreceptor damage.

Low intensity diffuse white fluorescent light (1,000 lx for 2 h) exclusively induced photoreceptor damage in the inferior retina of albino rats; the temporal retina showed extensive damage, whereas the nasal retina revealed threshold lesions prior to recovery. To expand our morphological data, further experiments were undertaken to determine if glial fibrillary acidic protein (GFAP) expression was associated with the regions of photoreceptor damage. To follow the time course of GFAP expression, immunoblot analysis was carried out on retinal homogenates of dark-adapted (control) rats and light-exposed rats returned to cyclic light for 0 h, 1, 2, 3 and 6 days. A significant twofold increase in GFAP immunoreactivity over controls was observed in the retinas of light-exposed rats returned to cyclic light for 6 days. Using an indirect immunohistochemical method, retinal sections of the control and light-exposed rats allowed to recover for 6 days were stained for GFAP. GFAP immunoreactivity was localised to the astrocytes and Müller cells. Moreover, GFAP staining in Müller cells in the retinas of control animals was uniformly restricted to rare end-feet. In contrast, a gradient of GFAP immunoreactivity was observed in experimental rats, rising from the superior retina to the inferior temporal quadrant; the GFAP staining in the inferior nasal quadrant was intermediate. Thus, GFAP immunoreactivity was proportional to photoreceptor damage. Interestingly, no GFAP induction could be demonstrated in the pineal glands of light-exposed rats.

Effect of dietary fish oil on acute light-induced photoreceptor damage in the rat retina.

PURPOSE: Previous studies have shown that ingestion of fish oil (FO) containing a high proportion of n-3 polyunsaturated fatty acids increases the susceptibility of cellular membranes to oxidative damage in various tissues. In the retina, lipid peroxidation is thought to be a major mechanism contributing to light-induced lesions. Therefore, we investigated the effect of FO on acute light-induced photoreceptor damage. METHODS: For 2 months, weanling rats were fed diets containing either soybean oil (SOY) or FO as main lipid component. RESULTS: Rats fed FO had significantly higher levels of eicosapentaenoic acid (EPA, 20:5n-3) and higher ratios of EPA to arachidonic acid (AA, 20:4n-6) in retinal phospholipids and diacylglycerols than rats fed SOY. The levels of docosahexaenoic acid (DHA, 22:6n-3) were similar in both dietary groups. The susceptibility to lipid peroxidation was enhanced in the isolated retina of FO-fed rats as shown by higher levels of thiobarbituric acid reactive substances after incubation of retinal membranes with Fe2+/ascorbate. The retinal content of alpha-tocopherol was similar in SOY- and FO-fed animals. Light damage consisting of acute rod outer segment (ROS) disruptions was induced by exposing dark-adapted animals to 600 to 700 lux (230 to 260 microW/cm2) of white fluorescent light for 30 minutes. Damage was quantitated using a computerized multifunctional image analysis of retinal thin sections. Although structural alterations of the ROS were present in both groups, FO-fed rats showed less damage at the base of the ROS. This occurred in spite of higher rhodopsin levels in FO-fed rats. There was no effect of diet on retinal morphology in dark-adapted rats. CONCLUSION: These results indicate that FO does not enhance the susceptibility to acute ROS disk disruptions in the rat retina. Our study further suggests that FO exerts a partial protective effect that may be related to changes in the formation of lipid mediators derived from EPA and AA in retinal phospholipids.

Light and lithium effects in the rat retina: modification by the PAF antagonist BN 52021.

We tested the effect of an antagonist of platelet-activating factor (PAF), BN 52021, on both acute light-induced and light plus lithium-induced rod outer segment (ROS) lesions. Rats were fed lithium carbonate (2.6 g/kg chow) for 3 weeks. Half of the lithium-treated rats received BN 52021 (25 mg/kg) via gastric intubation prior to light exposure. Control and treated rats were exposed to 400-450 lux (measured at the eye level of the rats) of diffuse, white fluorescent light for 30 min, followed by 2 h of darkness and then decapitated. The eyes were removed and prepared for light and electron microscopic observation. The structural alterations of ROS were quantified from electron micrographs using a multifunctional computer image-analysis system. Our data show a significant reduction of ROS lesions by BN 52021, and this is most pronounced in light plus lithium-treated rats. Furthermore, in confirmation of previous studies, chronic lithium treatment significantly augmented light-elicited phagosome numbers, and BN 52021 reduced this effect. Our findings thus suggest that light and lithium may act via PAF responses in the rat retina.

Disk-shedding in the rat retina: lithium dampens the circadian rhythm but potentiates the light response.

Disk-shedding in the rat retina undergoes a circadian rhythm. Chronic lithium treatment significantly dampens the rhythm in constant darkness, but does not alter the timing or amplitude of the peak in a light-dark cycle. Lithium potentiates light-elicited disk-shedding with a maximal effect at the end of the subjective light phase, when light alone evokes only a moderate response. Although serum lithium levels show a diurnal variation, retinal lithium concentration remains high throughout 24 h. Thus lithium induces alterations in retinal rhythms as well as in photoreceptor metabolism.

Ultrahistochemical localization of adenylate cyclase activity in the electric organ of Torpedo marmorata.

The lead pyrophosphate precipitation technique was used to visualize adenylate cyclase activity with the electron microscope in unfixed electric organ and synaptosomes of Torpedo marmorata, with special attention to presynaptic membranes. Specificity of the deposition of reaction product was ensured by using 5'-adenylyl imidodiphosphate as substrate and 5'-guanylyl imidodiphosphate and sodium fluoride as activators. Under suitable conditions a reaction product was deposited on the Schwann cell, on presynaptic vesicles, on the inner side of membranes of cisternae and on glycogen granules of the presynaptic region of the endplate. In some cases, a precipitate was also found on postsynaptic membranes of the synaptic cleft and on mitochondria. In isolated synaptosomes localization of the reaction product was identical with that of minced tissue. However, most strikingly, on presynaptic membranes no precipitate was ever found, neither in pieces of electric organ nor in isolated synaptosomes. Furthermore, the extended membrane system of the postsynaptic region of the electroplax remained always free of lead pyrophosphate precipitate.

Incorporation of small unilamellar liposomes loaded with horseradish peroxidase into isolated nerve endings from electric organ of Torpedo marmorata.

A population of small unilamellar liposomes loaded with horseradish peroxidase, an electron dense marker, was prepared by passing the lipid-protein-detergent micelles through Sephadex G-50. By electron microscopy it was shown that these artificial lipid vesicles were incorporated into the cytoplasm of isolated pure cholinergic nerve endings from the electric organ of Torpedo marmorata. This liposome carrier system may be useful in manipulating the internal parameters involved in presynaptic processes in the electric organ.

Electron microscopic localization of choline acetyl transferase activity in the electric organ of Torpedo marmorata.

The light microscopic method for demonstration of choline acetyltransferase (CAT) activity based on the formation of a lead mercaptide of free SH-acetyl Coenzyme A was adapted for electron microscopy. In samples of electric organ of Torpedo marmorata CAT activity was found to be restricted to synaptic vesicles and cysternae. The precipitate formed was mostly fine grained and distributed more or less evenly throughout the vesicles. Generally, the reaction product seemed not to adhere to the inner side of the vesicle membrane. CAT activity was found only in the presynaptic region of the synapse, neither the synaptic cleft nor the postsynaptic region reacted positively. CAT activity was found also within synaptic vesicles in nerve endings prepared from electric organ. Samples of Torpedo brain reacted positively too. Complete suppression of CAT activity with inhibitors, judged on the basis of lead mercaptide deposited, was rather difficult to achieve. From a group of 10 presumed enzyme inhibitors, only 2 compounds reacted satisfactorily, namely trans-1,2-dihydro-2-imino-4-(1-naphthylvinyl)-1-pyridine-ethanol hydrobromide and 5,5-dithio-bis-(2-nitrobenzoic acid) (3,3'-6). On the whole, the results obtained show the viability of the method used and furthermore it offers also some new insight into the turnover of acetylcholine, since it may be deduced from the results that under certain circumstances acetylcholine may be synthesized in synaptic vesicles.

Morphometric analyses of the electric organ of Torpedo: the influence of different fixative modes on the vesicle diameter.

The influences of various fixatives on the vesicle size of the electric organ of Torpedo marmorate were investigated. Thin section and freeze etched preparations were examined under the electron microscope. In thin section increased vesicle diameters were observed compared with the freeze etched preparations. The same experiments in different torpedo fish led to significantly different vesicle sizes observed. Variations of the molarity, the pH and osmolarities result in particularly high differences in vesicle diameters. Using Karnovsky's method (1965) and a fixative consisting of 2.5% glutaraldehyde in 0.2 M cacodylate buffer, pH 7.2, results in vesicle sizes comparable to those reported by other authors. Results obtained from freeze etched preparations are not comparable in general with results from thin section experiments with the same fixative.

Total body water content in normal and grossly obese women.

Total body water content was estimated for 27 normal and 27 obese women by an isotope dilution technique using tritiated water. The mean total body water content expressed in absolute amounts was significantly raised in the obese group (P less than 0-001), but was significantly lower (P less than 0-001) when the values were expressed as a percentage of body weight. Significant correlations were found between weight and total body water content (P less than 0-001 and P less than 0-05) for the normal and obese subjects respectively. Separate regression equations based on height and weight were calculated for the normal and obese subjects, and good agreement was found in most instances between the measured and calculated total body water contents. The overweight women, with two exceptions, had total body water values in the expected range, which indicated that they were accumulating fat, not water. Although excess water was found in 2 women, this contributed only about 50% to their overweight.