High density carbon fiber arrays for chronic electrophysiology, fast scan cyclic voltammetry, and correlative anatomy

OBJECTIVE

Multimodal measurements at the neuronal level allow for detailed insight into local circuit function. However, most behavioral studies focus on one or two modalities and are generally limited by the available technology.

APPROACH

Here, we show a combined approach of electrophysiology recordings, chemical sensing, and histological localization of the electrode tips within tissue. The key enabling technology is the underlying use of carbon fiber electrodes, which are small, electrically conductive, and sensitive to dopamine. The carbon fibers were functionalized by coating with Parylene C, a thin insulator with a high dielectric constant, coupled with selective re-exposure of the carbon surface using laser ablation.

MAIN RESULTS

We demonstrate the use of this technology by implanting 16 channel arrays in the rat nucleus accumbens. Chronic electrophysiology and dopamine signals were detected 1 month post implant. Additionally, electrodes were left in the tissue, sliced in place during histology, and showed minimal tissue damage.

SIGNIFICANCE

Our results validate our new technology and methods, which will enable a more comprehensive circuit level understanding of the brain.

Eurecon: Equidistant uniform rigid-body ensemble constructor

Conformational ensembles comprise one of the fundamental concepts in statistical bioinformatics and appear in a variety of applications, e.g. molecular docking, virtual screening, searching for pharmacophores, etc. High-throughput applications require billions of conformations to be considered, thus, one often uses the rigid-body representation of molecules or its fragments to cope with the computational cost. Of particular interest is generation of the near-native conformational ensembles, which consist of conformations structurally close to the biologically relevant ones. One possible way to compose such ensembles is to control the root mean square deviation (RMSD) between the original and the generated conformations. To the best of our knowledge there is no computational approach that guarantees that all the generated conformations have the desired RMSD with respect to the reference structure. In this study we presented a fast algorithm for the construction of rigid-body conformational ensembles, which possess two main properties: (i) each generated conformation has a fixed RMSD with respect to the original conformation, (ii) generated conformations are distributed uniformly over the sphere of axes corresponding to the rigid-body motions. The algorithm is very efficient, it does not require any standard RMSD computation between the conformations and has the O(N + M) complexity to generate the required rigid-body transforms, where N is the number of atoms in the system, and M is the size of the conformational ensemble. Eurecon is applicable to an arbitrary atomic system, thus, it could be used for molecular systems of various size and type. We demonstrated Eurecon application by generating near-native conformational ensembles for a ligand placed inside a binding site, a protein dimer embedded into a membrane, and a ribosomal complex. We implemented the developed algorithm in C++ and called it Eurecon, which stands for Equidistant Uniform Rigid-body Ensemble CONstructor. A user-friendly interface allows to define the desired RMSD value, the relative amplitudes for rotation and translation motions by means of the partition parameter, and the set of axes corresponding to the rigid-body motions. Eurecon is available as the SAMSON Element (https://samson-connect.net).

Rapid induction of dopamine sensitization in the nucleus accumbens shell induced by a single injection of cocaine

Repeated intermittent exposure to cocaine results in the neurochemical sensitization of dopamine (DA) transmission within the nucleus accumbens (NAc). Indeed, the excitability of DA neurons in the ventral tegmental area (VTA) is enhanced within hours of initial psychostimulant exposure. However, it is not known if this is accompanied by a comparably rapid change in the ability of cocaine to increase extracellular DA concentrations in the ventral striatum. To address this question we used fast-scan cyclic voltammetry (FSCV) in awake-behaving rats to measure DA responses in the NAc shell following an initial intravenous cocaine injection, and then again 2-h later. Both injections quickly elevated DA levels in the NAc shell, but the second cocaine infusion produced a greater effect than the first, indicating sensitization. This suggests that a single injection of cocaine induces sensitization-related plasticity very rapidly within the mesolimbic DA system.

The sensory features of a food cue influence its ability to act as an incentive stimulus and evoke dopamine release in the nucleus accumbens core

The sensory properties of a reward-paired cue (a conditioned stimulus; CS) may impact the motivational value attributed to the cue, and in turn influence the form of the conditioned response (CR) that develops. A cue with multiple sensory qualities, such as a moving lever-CS, may activate numerous neural pathways that process auditory and visual information, resulting in CRs that vary both within and between individuals. For example, CRs include approach to the lever-CS itself (rats that “sign-track”; ST), approach to the location of reward delivery (rats that “goal-track”; GT), or an “intermediate” combination of these behaviors. We found that the multimodal sensory features of the lever-CS were important to the development and expression of sign-tracking. When the lever-CS was covered, and thus could only be heard moving, STs not only continued to approach the lever location but also started to approach the food cup during the CS period. While still predictive of reward, the auditory component of the lever-CS was a much weaker conditioned reinforcer than the visible lever-CS. This plasticity in behavioral responding observed in STs closely resembled behaviors normally seen in rats classified as “intermediates.” Furthermore, the ability of both the lever-CS and the reward-delivery to evoke dopamine release in the nucleus accumbens was also altered by covering the lever—dopamine signaling in STs resembled neurotransmission observed in rats that normally only GT. These data suggest that while the visible lever-CS was attractive, wanted, and had incentive value for STs, when presented in isolation, the auditory component of the cue was simply predictive of reward, lacking incentive salience. Therefore, the specific sensory features of cues may differentially contribute to responding and ensure behavioral flexibility.

Microvascular reconstruction after resection of soft tissue sarcoma of the leg

Background

Limb-sparing surgery and satisfactory functional outcome is the goal of extremity soft tissue sarcoma (STS) surgery. Tissue defects after tumour excision are often extensive, and microvascular reconstruction is frequently required.

Methods

Seventy-three patients with STS of the leg requiring microvascular reconstruction were treated between 1985 and 2006. Radiotherapy was delivered if the microscopic surgical margin was less than 2·5 cm.

Results

Mean follow-up was 65·9 months. Seventy-five free flaps were performed, with a success rate of 95 per cent. One patient died within a month of surgery. Five-year local recurrence-free survival was 82 per cent, metastasis-free survival 59 per cent, disease-free survival 56 per cent and disease-specific overall survival 70 per cent. Fifty-five (75 per cent) of the 73 patients were able to walk normally or had only minor walking impairment.

Conclusion

Without microvascular reconstruction, amputation would have been necessary in most patients. Microvascular reconstruction is safe and reliable in lower extremity STS reconstruction.

[Questionnaire study of general practitioners regarding experience and attitude to opioid substitution therapy]

General practitioners (GPs) in their surgeries and substitution treatment centres are the major providers of opioid maintenance treatment in a number of European countries. Although in the Czech Republic any GP has been allowed to prescribe buprenorphine (Subutex) since 2001, the opioid substitution treatment provided by primary care professionals has not been the subject of research to date.

OBJECTIVE

To collect and analyze data on GPs' experience gained with opioid maintenance treatment in the Czech Reupblic, their attitudes and needs.

METHOD

A structured questionnaire was distributed via the Bulletin of the Association of General Practitioners and district Association representatives. The validity of study results may be affected by a low respondence rate (10%) with 398 questionnaires only returned by mail.

RESULTS

Twenty-eight (7%) GPs reported to have gained experience with buprenorphine which was most frequently prescribed in the regions with the highest prevalence of heroin users, i.e. in Prague and the Ustí nad Labem region (27% and 12%, respectively). Other regions, including wes- tern and southern Bohemia with relatively high prevalence of heroin users, showed lower buprenorphine prescription rates (0-6%). Most buprenorphine prescribers (78%) rated their experience as positive or highly positive. Availability and effectiveness were seen as the main pros of the substitution treatment. One third of the GPs who have not prescribed opioid maintenance treatment yet are considering doing so in the future. Greater awareness of drug abuse issues and availability of methodical guidance and consulting in opioid substitution treatment are going to become the most relevant factors in the future. Possible reportability of data on opioid maintenance treatment to a central registry does not seem to be a major obstacle to implementing the substitution treatment in the GPs' surgeries. Decision makers should take advantage of the GPs' potential to promote the opioid maintenance treatment in the Czech Republic.

[Recommendations for the treatment of tobacco dependence]

This first Czech version of guidelines formulated by the working group of mentioned medical associations is based on current literature and international guidelines. They are aimed mainly on clinical medicine and on incorporation of this treatment into the health care system according to WHO recommendations. They should serve to the treatment of tobacco dependence at any level: during any contact with the smoking patient (short intervention), in specialised centres or for the health care providers or health system itself.

[Comprehensive care of drug addiction during a 5-year period at the methadone center in Prague]

Methadone maintenance program in General Faculty Hospital in Prague has been in operation for five years since August 1997. During this period a broad spectrum of complex care was supported to opioid drug addicts. Not only substitution of methadone or buprenorphine but also psychiatric, social and health care was guaranteed. The goal of this article is the information about our experience achieved during the five-year existence of the methadone maintenance program.

[Partial resection of the spleen in the treatment of benign and traumatic lesions]

It has been thought that the spleen is an organ without important functions, until recently. That is, why splenectomy has been the procedure of choice in a treatment of splenic diseases. Even now, when we know the functional [figure: see text] importance of the spleen, splenectomy is performed frequently, regardless of its complications. The need of spleen functions salvage, favours partial resection of the spleen as competitive in a treatment of its traumatic and benign lesions. Improvement in diagnostic procedures, surgical techniques, transfusiology and postoperative treatment, will promote it as a treatment of choice. The authors of this study have experience with 17 partial resections of the spleen for traumatic, 11 for benign lesions of the spleen, and one ectopic spleen with hypersplenism, without mortality and with insignificant complications.

[Partial resection of the spleen and spleno-renal shunt in the treatment of portal hypertension with splenomegaly and hypersplenism]

Some of serious hepatic diseases with cirrhosis may be complicated by portal hypertension, splenomegaly and hypersplenism. Splenomegaly inhibits regenerative processes of the liver, and also intensifies sequestration of the cellular components of blood up to hypersplenism. Cytopenia caused by hypersplenism is aggravated by negative hepatic influence on bone marrow activity-hemathopoesis, and also by recurrent bleeding from oesophageal varices, and from the other site of gastrointestinal tract. This circle of pathologic conditions may be interrupted only by liver transplantation, until which patients are jeopardized by acute bleeding and chronic anemia. Partial resection of the spleen and splenorenal shunt may correct portal hypertension and hypersplenism, prevent gastrointestinal bleeding, and alleviate hepatic regenerative processes inhibition. In this study, 51 patients with partial resection of the spleen and splenorenal shunt, were analyzed.

Primary soft tissue sarcoma and its local recurrence: genetic changes studied by comparative genomic hybridization

The aims of this study were to compare genetic aberrations in primary soft-tissue sarcomas and their local recurrences and to evaluate the genetic changes occurring during tumor progression. A primary soft-tissue sarcoma and its subsequent local recurrence were analyzed in 20 tumor pairs by comparative genomic hybridization. The samples were obtained before application of radio- or chemotherapy. Copy number aberrations were detected in 50% of the primary tumors and in 70% of the local recurrences. In primary tumors, the mean number of changes was 2.45 (range, 0 to 11) whereas in local recurrences, it was 5.05 (range, 0 to 17). The mean increase of changes from primary tumor to local recurrence was 2.6 per tumor pair (P =.02). Gains predominated over losses in both primary tumors and their local recurrences. The number of high-level amplifications was twofold in local recurrences. The most frequent gain affected 5p14-p15.1 (10% of primary tumors, 25% of local recurrences) and the most frequent loss, 9p (9p21-pter in 5% of primary tumors; 9p22-pter in 30% of local recurrences). In conclusion, our results show an increase in the number of genetic changes in local recurrences, due to tumor progression. Loss at 9p and gains at 5p and 20q were more frequent in local recurrences, and high-level amplification of 18p11.3 was not detected in any of the primary tumors. Although all these alterations were not specific to local recurrences, they may represent changes important during tumor progression.

Ethanol and oxidative stress

This article represents the proceedings of a workshop at the 2000 ISBRA Meeting in Yokohama, Japan. The chair was Albert Y. Sun. The presentations were (1) Ethanol-inducible cytochrome P-4502E1 in alcoholic liver disease, by Magnus Ingelman-Sundberg and Etienne Neve; (2) Regulation of NF-kappaB by ethanol, by H. Matsumoto, Y. Nishitani, Y. Minowa, and Y. Fukui; (3) Chronic ethanol consumption increases concentration of oxidized proteins in rat liver, by Shannon M. Bailey, Vinood B. Patel, and Carol C. Cunningham; (4) Antiphospholipids antibodies and oxidized modified low-density lipoprotein in chronic alcoholic patients, by Tomas Zima, Lenka Fialova, Ludmila Mikulikova, Ptr Popov, Ivan Malbohan, Marta Janebova, and Karel Nespor; and (5) Amelioration of ethanol-induced damage by polyphenols, by Albert Y. Sun and Grace Y. Sun.

Oxidative stress, metabolism of ethanol and alcohol-related diseases

Alcohol-induced oxidative stress is linked to the metabolism of ethanol. Three metabolic pathways of ethanol have been described in the human body so far. They involve the following enzymes: alcohol dehydrogenase, microsomal ethanol oxidation system (MEOS) and catalase. Each of these pathways could produce free radicals which affect the antioxidant system. Ethanol per se, hyperlactacidemia and elevated NADH increase xanthine oxidase activity, which results in the production of superoxide. Lipid peroxidation and superoxide production correlate with the amount of cytochrome P450 2E1. MEOS aggravates the oxidative stress directly as well as indirectly by impairing the defense systems. Hydroxyethyl radicals are probably involved in the alkylation of hepatic proteins. Nitric oxide (NO) is one of the key factors contributing to the vessel wall homeostasis, an important mediator of the vascular tone and neuronal transduction, and has cytotoxic effects. Stable metabolites--nitrites and nitrates--were increased in alcoholics (34.3 +/- 2.6 vs. 22.7 +/- 1.2 micromol/l, p < 0.001). High NO concentration could be discussed for its excitotoxicity and may be linked to cytotoxicity in neurons, glia and myelin. Formation of NO has been linked to an increased preference for and tolerance to alcohol in recent studies. Increased NO biosynthesis also via inducible NO synthase (NOS, chronic stimulation) may contribute to platelet and endothelial dysfunctions. Comparison of chronically ethanol-fed rats and controls demonstrates that exposure to ethanol causes a decrease in NADPH diaphorase activity (neuronal NOS) in neurons and fibers of the cerebellar cortex and superior colliculus (stratum griseum superficiale and intermedium) in rats. These changes in the highly organized structure contribute to the motor disturbances, which are associated with alcohol abuse. Antiphospholipid antibodies (APA) in alcoholic patients seem to reflect membrane lesions, impairment of immunological reactivity, liver disease progression, and they correlate significantly with the disease severity. The low-density lipoprotein (LDL) oxidation is supposed to be one of the most important pathogenic mechanisms of atherogenesis, and antibodies against oxidized LDL (oxLDL) are some kind of epiphenomenon of this process. We studied IgG oxLDL and four APA (anticardiolipin, antiphosphatidylserine, antiphosphatidylethanolamine and antiphosphatidylcholine antibodies). The IgG oxLDL (406.4 +/- 52.5 vs. 499.9 +/- 52.5 mU/ml) was not affected in alcoholic patients, but oxLDL was higher (71.6 +/- 4.1 vs. 44.2 +/- 2.7 micromol/l, p < 0.001). The prevalence of studied APA in alcoholics with mildly affected liver function was higher than in controls, but not significantly. On the contrary, changes of autoantibodies to IgG oxLDL revealed a wide range of IgG oxLDL titers in a healthy population. These parameters do not appear to be very promising for the evaluation of the risk of atherosclerosis. Free radicals increase the oxidative modification of LDL. This is one of the most important mechanisms, which increases cardiovascular risk in chronic alcoholic patients. Important enzymatic antioxidant systems - superoxide dismutase and glutathione peroxidase - are decreased in alcoholics. We did not find any changes of serum retinol and tocopherol concentrations in alcoholics, and blood and plasma selenium and copper levels were unchanged as well. Only the zinc concentration was decreased in plasma. It could be related to the impairment of the immune system in alcoholics. Measurement of these parameters in blood compartments does not seem to indicate a possible organ, e.g. liver deficiency.

Soft tissue sarcomas of the lower extremity: surgical treatment and outcome

AIMS

The aims of this retrospective follow-up study were to evaluate the justification for limb-saving multi-disciplinary treatment of soft tissue sarcomas (STS) and to report the results achieved by our treatment protocol. Local control was studied, with emphasis on tumour depth, operation margin and need for post-operative radiotherapy.

METHODS

We examined 130 patients with STS in the lower limb referred to the multi-disciplinary group of Helsinki University Central Hospital. For the survival analysis 106 patients with local disease remained. The goal of treatment was to preserve a functional limb. Wide excision was attempted. If the margin was less than 2.5 cm, post-operative radiotherapy (RT) was delivered to all except 20 patients.

RESULTS

Ninety-two per cent of the patients were treated by limb salvage. The success rate of free flaps was 16 out of 18. The 5-year disease-specific overall survival was 76%, metastasis-free survival 72% and local control 79%. Prognostic factors for local recurrence were extracompartmental site and large size; for development of metastases high grade, extracompartmental site and large size; for decreased disease-specific overall survival high grade, large size and advanced age. Local control of intramuscular tumours (n=6) was 100%, subcutaneous tumours (n=38) 94% and tumours penetrating the deep or muscle fascia and those locating extracompartmentally (n=62) 67%.

CONCLUSIONS

Limb salvage in patients with STS is possible with an acceptable outcome by selective combination of treatment modalities. Modern plastic surgical methods with free tissue transfers are successful and often needed. Subcutaneous and intramuscular tumours have good local control. The outcome is poorest for tumours penetrating the deep or muscle fascia and for those located extracompartmentally, and patients with such tumours might be a target for adjuvant therapy. Treatment should be coordinated by multidisciplinary teams.

Antibodies against phospholipids and oxidized LDL in alcoholic patients

Antiphospholipid antibodies (APA) are a generic term describing antibodies that recognize various phospholipids. Hepatocyte damage is a cardinal event in the course of alcoholic liver injury and autoantibodies against phospholipids could play an important role in this process. APA in alcoholic patients seem to reflect membrane lesions, impairment of immunological reactivity, liver disease progression and they correlate significantly with disease severity. LDL oxidation is supposed to be one of the most important pathogenic mechanisms of atherosclerosis and antibodies against oxidized low-density lipoprotein (oxLDL) are some kind of an epiphenomenon of this process. The scope of our study was to determine some autoantibodies (IgG-oxLDL and antiphospholipid antibodies) and their possible changes in alcoholic patients. We studied IgG-oxLDL and four APA - anticardiolipin antibodies (ACA), antiphosphatidylserine antibodies (APSA) antiphosphatidylethanolamine antibodies (APE) and antiphosphatidylcholine antibodies (APCA) in 35 alcoholic patients with mildly affected liver function at the beginning of the abuse treatment. The control group consisted of 60 healthy blood donors. In the studied group, we obtained positive results concerning total ACA in 17.1 % of alcoholic patients (8.3 % in the control group), 11.4 % IgG-ACA (6.7 %), 8.6 % IgM-ACA (3.3 %), 14.3 % total APE (6.7 %), 14.3 % total APCA (8.3 %) and 20 % total APSA (8.3 % in the control group). The IgG-oxLDL (406.4+/-52.5 vs 499.9+/-52.5 mU/ml) was not affected in alcoholic patients. We conclude that the autoantibodies against oxLDL are present in sera of alcoholics and healthy blood donors. Based on our results which revealed a wide range of IgG-oxLDL titres in the healthy population, this parameter does not appear to be very promising for the evaluation of the risk of atherosclerosis. Alcoholics with only mild affection of liver functions did not exhibit a significantly higher prevalence of all studied antiphospholipid antibodies (ACA, APSA, APE, APCA) which could lead to membrane lesions in these patients.

Karyotype study of Rana camerani and comparisons with the other 26-chromosome European brown frog species (Amphibia, Anura)

The results of a detailed morphological and morphometrical chromosome analysis of Rana camerani (2n = 26) are described. It was established that the karyotype of this species consisted of three homologous pairs of large metacentrics, two homologous pairs of large submetacentrics, three homologous pairs of small metacentrics, two homologous pairs of small submetacentrics, and three homologous pairs of small subtelocentrics. Morphologically discernible sex chromosomes were not found. The similarity and peculiarities in the R. camerani karyotype and those of R. temporaria, R. dalmatina and R. graeca are discussed. This comparative karyotype analysis has suggested the possibility for developing a general chromosomal formula, by means of which these 26-chromosome species could be characterized.

[Stimulants and addiction]

Stimulants (methamphetamine) produced illegally in domestic laboratories play today - key role on the drug scene in the Czech Republic. In the past, however, a similar place was held by some preparations used (though to a limited extent) lege artis. At present we can observe an increased interest in stimulants in both spheres-on the mentioned drug scene as well as in medicine. The article deals in particular with the second sphere, i.e. the problem of the addictive character of stimulants prescribed by physicians.

[Blood autotransfusion in head and neck surgery]

Autotransfusion as a method of blood compensation after multilative surgical operation in cases of malignant neoplasm of the maxillofacial region, was introduced in our clinical practice in 1989, and up to now we have performed it in a group of 23 patients. It has been known that an autotransfusion depends on the patients' general health situation, hemoglobin level, hematocrit and iron concentration in serum. We exfused at least three days before operation 450 ml of blood from each patient. The blood was taken into plastic bags and kept in the refrigerator at the temperature of +4 degrees C. The decrease of serum iron concentration was approximately 54.26% in all tested patients that demanded the substitution therapy with iron together with vitamin C before and after surgery. There was neither prolongation of postoperative treatment nor complications associated with this method of post-operative blood loss compensation. Based on obtained results we could conclude that the best method of inter- and postoperative blood compensation was autotransfusion, taking care about factors which could limit the possibilities of its applications.

Long-term treatment with different calcium- and calmodulin-antagonists induces changes in rat brain alpha-adrenoceptors

1. The binding characteristics (Bmax and Kd) of the alpha-adrenoceptor radioligand [3H] WB4101 in crude membrane fraction (fraction P2) from cerebral cortex were studied after 13-day oral treatment of male Wistar rats with the Ca(2+)-antagonists nifedipine (20 mg/kg), verapamil (50 mg/kg), flunarizine (10 mg/kg) and with the calmodulin-antagonist trifluoperazine (TFP) (3 mg/kg). 2. A significant reduction of the binding sites (Bmax) for [3H] WB4101 was established after the three Ca(2+)-antagonists as well as after TFP treatment. 3. Different changes in the affinity constant (Kd) of brain adrenoceptors were observed depending on the type of the Ca2+ or CaM-antagonist used: nifedipine did not change the Kd value, verapamil and TFP decreased whereas flunarizine increased the Kd value. 4. Relationships between Ca ions and alpha-adrenoceptor functions are suggested.

Changes in benzodiazepine receptors of rat brain after long-term treatment with the Ca(2+)-antagonists nifedipine, verapamil, flunarizine and with the calmodulin antagonist trifluoperazine

1. The binding of [3H]flunitrazepam to benzodiazepine receptors in the cerebral cortex and hippocampus (membrane fraction P2) was studied after 13-day oral treatment of male Wistar rats with the Ca(2+)-antagonists nifedipine (20 mg/kg), verapamil (50 mg/kg), flunarizine (10 mg/kg) and with the calmodulin (CaM)-antagonist trifluoperazine (TFP) (3 mg/kg). 2. The changes in the binding characteristics of the benzodiazepine receptors in the frontal cortex were studied in vitro after the addition of nifedipine (10(-6) and 10(-5) M) and verapamil (10(-6) and 10(-5) M). 3. A significant decrease of the binding capacity (Bmax) of [3H]flunitrazepam was established after in vivo treatment with the three Ca(2+)-antagonists as well as after TFP, the decrease being much more pronounced in the hippocampus. 4. Changes in the affinity values (Kd) of [3H]flunitrazepam binding were found in neither of the groups. 5. No data for a direct interaction of nifedipine and verapamil with the brain benzodiazepine receptors were obtained in in vitro experiments.

Cisapride and cimetidine in the treatment of erosive esophagitis

The efficacy of cisapride, as compared with cimetidine, in the treatment of erosive esophagitis was studied in a double-blind trial. One hundred and twenty-nine patients were assigned to one of four dosage schedules: cisapride 10 mg b.i.d. (20 mg group) or q.i.d. (40 mg group), or cimetidine 400 mg b.i.d. (800 mg group) or q.i.d. (1600 mg group). Treatment lasted 8 to 12 weeks. The degree of esophagitis and the severity of diurnal and nocturnal heartburn and regurgitation were significantly (p less than 0.01) reduced in the four treatment groups. Endoscopy did not show any significant differences among the four groups, although cisapride tended to be more effective in moderate to severe esophagitis, in which cases mucosal healing (i.e. absence of erosions and ulcers) was observed in 69%, 64%, 55% and 55% of the patients treated with cisapride 40 mg, cisapride 20 mg, cimetidine 1600 mg and cimetidine 800 mg. Improvement in reflux symptoms in the two cisapride groups was not significantly different from that in the cimetidine 1600 mg group, but was better (p less than 0.05) than that in the cimetidine 800 mg patients. The severity score for all reflux symptoms had decreased by 79%, 74% (cisapride 40 mg and 20 mg), 69% and 57% (cimetidine 1600 mg and 800 mg) by the end of treatment. These results show that cisapride is at least as effective as acid-suppressing therapy in patients with reflux esophagitis, and is therefore a valuable alternative to it.

Protective effect of rioprostil on indomethacin-induced lesions of gastric and duodenal mucosa in healthy volunteers

The protective effect of rioprostil against gastroduodenal mucosal lesions induced by indomethacin is investigated in a double-blind controlled trial on 36 healthy adult volunteers, divided into three groups. All the volunteers are treated with indomethacin, 50 mg t.d.s. during a period of 5 days. The first group is treated with placebo, the second with rioprostil, 300 micrograms, and the third with rioprostil, 600 micrograms. Endoscopies are performed before and after treatment. Blood samples for high performance liquid chromatography determination of indomethacin plasma concentrations are taken on the 6th day, before the last dose of indomethacin is administered, and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12 and 24 h after the last dose of indomethacin. It is found that in both doses rioprostil exerts a protective effect against indomethacin-induced lesions, reducing the appearance rate of erosions from 67% to 17% statistically significant in the 600 micrograms group. The bioavailability of indomethacin in the three groups does not differ significantly.

[Reflux esophagitis (clinical and endoscopic studies)]

The results from the esophagoscopies of patients with esophagitis are reported. The diagnosis esophagitis was made in 238 patients (17.5%) out of the 1389 esophagoscopies performed. Esophagitis incidence is presented according to age groups. With the involvement of the distal third of esophagus proved to be 189 patients (71.0%). The incidence of reflux-esophagitis was studied in some diseases of stomach and duodenum. Reflux-esophagitis is more frequently found in patients with resected stomach, duodenal and gastric ulcers, than in patients with atrophic and superficial gastritis. The clinical symptoms, the characteristic endoscopic and histologic changes in esophageal mucosa were studied in a group of 56 patients with reflux-esophagitis. Esophagoscopy with intentional biopsy is the most valuable method for the diagnosis, precision of the stage and dynamics of reflux-esophagitis.