The value of "diaphragmatic relaxing incision" for the durability of the crural repair in patients with paraesophageal hernia: a double blind randomized clinical trial

Background

Surgical repair of paraesophageal hernias (PEHs) is burdened with high recurrence rates, and hitherto various techniques explored to enforce the traditional crural repair have not been successful. The hiatal reconstruction in PEH is exposed to significant tension, which may be minimized by adding a diaphragmatic relaxing incision to enhance the durability of the crural repair.

Patients and methods

All individuals undergoing elective laparoscopic repair of a large PEH, irrespective of age, were considered eligible. PEHs were classified into types II-IV. The preoperative work-up program included multidetector computed tomography and symptom assessment questionnaires, which will be repeated during the postoperative follow-up. Patients were randomly divided into a control group with crural repair alone and an intervention group with the addition of a left-sided diaphragmatic relaxing incision at the edge of the upper pole of the spleen. The diaphragmatic defect was then covered by a synthetic mesh.

Results

The primary endpoint of this trial was the rate of anatomical PEH recurrence at 1 year. Secondary endpoints included symptomatic gastroesophageal reflux disease, dysphagia, odynophagia, gas bloat, regurgitation, chest pain, abdominal pain, nausea, vomiting, postprandial pain, cardiovascular and pulmonary symptoms, and patient satisfaction in the immediate postoperative course (3 months) and at 1 year. Postoperative complications, morbidity, and disease burden were recorded for each patient. This was a double-blind study, meaning that the operation report was filed in a locked archive to keep the patient, staff, and clinical assessors blinded to the study group allocation. Blinding must not be broken during the follow-up unless required by any emergencies in the clinical management of the patient. Likewise, the patients must not be informed about the details of the operation.

Trial Registration

ClinicalTrials.gov, identification number NCT04179578.

The effects of gasotransmitters inhibition on biochemical and haematological parameters and oxidative stress in propofol-anaesthetized Wistar male rats

This study aimed to investigate the effects of propofol through evaluating its interaction with nitric oxide (NO), hydrogen sulfide (H2S), and carbon monoxide (CO). Wistar male rats were divided in 4 groups: (1) bolus injection of propofol (1% 10 mg/mL, 100 mg/kg bw, i.p.); (2) Nω-nitro-l-arginine methyl ester (L-NAME; NO synthase inhibitor, 60 mg/kg bw, i.p.) + bolus injection of propofol (1% 10 mg/mL, 100 mg/kg bw, i.p.); (3) DL-propargylglycine (DL-PAG; H2S synthase inhibitor, 50 mg/kg bw, i.p.) + bolus injection of propofol (1% 10 mg/mL, 100 mg/kg bw, i.p.); (4) zinc protoporphyrin IX (ZnPPIX; CO synthase inhibitor, 50 μmol/kg bw, i.p.) + bolus injection of propofol (1% 10 mg/mL, 100 mg/kg bw, i.p.). Increased levels of albumins, low-density lipoproteins, alkaline phosphatase, amylase, high-sensitivity Troponin T, and fibrinogen were found in L-NAME + propofol group. Platelet crit, platelet count, total cholesterol, and high-density lipoproteins were elevated in ZnPPIX + propofol group. Hydrogen peroxide was increased in all groups treated with gasotransmitters inhibitors. Reduced glutathione was reduced in all groups, superoxide dismutase activity only in L-NAME + propofol. The effect of propofol on various biochemical, haematological, and oxidative stress markers may be at least in part mediated through interaction with 3 estimated gasotransmitters.

Inhibition of gasotransmitters production and calcium influx affect cardiodynamic variables and cardiac oxidative stress in propofol-anesthetized male Wistar rats

It has been assumed that the cardioprotective effects of propofol are due to its non-anesthetic pleiotropic cardiac and vasodilator effects, in which gasotransmitters (NO, H2S, and CO) as well as calcium influx could be involved. The study on isolated rat heart was performed using 4 experimental groups (n = 7 in each): (1) bolus injection of propofol (100 mg/kg body mass, i.p.); (2) L-NAME (NO synthase inhibitor, 60 mg/kg body mass, i.p.) + propofol; (3) DL-PAG (H2S synthase inhibitor, 50 mg/kg body mass, i.p.) + propofol; (4) ZnPPIX (CO synthase inhibitor, 50 μmol/kg body mass, i.p.) + propofol. Before and after the verapamil (3 μmol/L) administration, cardiodynamic parameters were recorded (dp/dtmax, dp/dtmin, systolic left ventricular pressure, diastolic left ventricular pressure, heart rate, coronary flow), as well as coronary and cardiac oxidative stress parameters. The results showed significant increases of diastolic left ventricular pressure following NO and CO inhibition, but also increases of coronary flow following H2S and CO inhibition. Following verapamil administration, significant decreases of dp/dtmax were noted after NO and CO inhibition, then increase of diastolic left ventricular pressure following CO inhibition, and increase of coronary flow following NO, H2S, or CO inhibition. Oxidative stress markers were increased but catalase activity was significantly decreased in cardiac tissue. Gasotransmitters and calcium influx are involved in pleiotropic cardiovascular effects of propofol in male Wistar rats.

The muscular expression of RAS in patients with achalasia

INTRODUCTION

Angiotensin II (AngII) elicits smooth muscle contractions via activation of AngII type 1 receptor (AT1R) in the intestinal wall and in sphincter regions in several species. Achalasia is a rare swallowing disorder and is characterized by a loss of the wave-like contraction that forces food through the oesophagus and a failure of the lower oesophageal sphincter to relax during swallowing.

AIMS AND METHODS

The present study was undertaken to elucidate expression and distribution of a local renin-angiotensin system (RAS) in the muscular layer of distal normal human oesophagus as well as in patients with achalasia using western blot analysis, immunohistochemistry and polymerase chain reaction (PCR).

RESULTS

AT1R, together with enzyme renin and cathepsin D expression were decreased in patients with achalasia. In contrast, the mast cells chymase, cathepsin G, neprilysin and the receptor for angiotensin 1-7 peptides, the MAS receptor, were increased in patients with achalasia.

CONCLUSION

The results showed the existence of a local RAS in human oesophageal muscular layer. The enzymes responsible for AngII production are different and there has been a shift in receptor physiology from AT1R to MAS receptor in patients with achalasia. These changes in the RAS might play a significant role in the physiological motor control for patients with achalasia.

Balkan Endemic Nephropathy Risk Associates to the hs1.2 Ig Enhancer Polymorphism

Balkan Endemic Nephropathy (BEN) is a kidney degenerative disease with a high incidence in the valleys of the Danube and tributary rivers. Many studies describe it as a multifactorial disease. Environmental as well immuno-inflammatory and genetic cofactors have been suggested to trigger the onset of the disease. Recently, high levels of C-reactive protein were demonstrated in BEN patients. We performed this study to evaluate the possible correlation of BEN with the polymorphism of the Ig heavy chain 3'Regulatory Region enhancer hsl.2 that is related to changes of consensus for trans activators binding within the DNA sequence and probably consequently autoimmune and inflammatory diseases. Therefore, we studied three cohorts: 1) 111 control subjects, 2) 95 BEN patients in dialysis therapy and 3) 133 components of a large family “J” in the same geographical area. The allelic frequencies of hsl.2 of BEN patients and family “J” components had similar decrease frequency of allele *1 and increase of allele *2 in respect to the controls. This trend suggests the association of allele *1 as a protective and allele *2 as a risk component for the disease. The presence of a consensus sequence for NF-Kb in the allele *2 may link the polymorphism to the inflammatory activity of BEN. This study supports the presence of an inflammatory pathway in BEN through the involvement of polymorphic enhancer hsl.2 influencing differently binding complexes and consequently the 3D structure of 3' Regulatory Region of IgH. Our work is the first study that clearly links BEN to a gene involved in the regulation of immune response.

Evaluation of the response to treatment in patients with idiopathic achalasia by the timed barium esophagogram: results from a randomized clinical trial

To choose which treatment would be most effective for the individual patient with newly diagnosed achalasia is difficult for the tending physician. A diagnostic tool that would allow prediction of the symptomatic and functional response after treatment for achalasia is therefore needed. The timed barium esophagogram (TBE) is a method that allows objective assessment of esophageal emptying, but the value of TBE in the clinical management of achalasia remains to be clarified. The aim of this study was first, to assess the ability of TBE to predict symptoms and treatment failure during post-treatment follow-up. Second, to determine whether esophageal emptying as assessed by TBE differs after treatment with pneumatic dilatation or laparoscopic myotomy. Fifty-one patients with newly diagnosed achalasia were prospectively randomized to pneumatic dilatation (n = 26) or laparoscopic myotomy (n = 25). Evaluation with TBE was performed before (n = 46) and after treatment (n = 43). The median interval between treatment and post-treatment TBE was 6 months, and the median follow-up time after the post-treatment TBE was 18 months. Following therapeutic intervention, TBE parameters did not differ significantly between treatment groups. However, significant correlations were found between the height of the barium column at 1 min and the symptom scores at the end of follow up for 'dysphagia for liquids' (P < 0.05, rho = 0.47), 'chest pain' (P < 0.05, rho = 0.42), and the 'Watson dysphagia score' (P < 0.05, rho = 0.46). Patients with less than 50% improvement in this TBE-parameter (height at 1 min) post-treatment had a 40% risk of treatment failure during follow-up. In summary, pneumatic balloon dilatation and laparoscopic myotomy similarly affected esophageal function as assessed by TBE-emptying. Lack of improvement in barium-column height post-treatment was associated with an increased risk of treatment failure which should motivate close surveillance in order to detect symptomatic recurrence at an early stage.

Pneumatic dilatation or laparoscopic cardiomyotomy in the management of newly diagnosed idiopathic achalasia. Results of a randomized controlled trial

BACKGROUND

The most effective therapeutic strategy in newly diagnosed achalasia is yet to be established. Therefore we designed a study in which pneumatic dilatation was compared to laparoscopic cardiomyotomy to which was added a partial posterior fundoplication.

PATIENTS AND RESULTS

A series of 51 patients (24 males, mean age 44 years) were randomly allocated to the therapeutic modalities (dilatation = 26, surgery = 25). All patients were followed for at least 12 months, and during that period the pneumatic dilatations strategy had significantly more treatment failures (P = 0.04). Only minor differences emerged between the study groups when symptoms, dysphagia scorings, and quality-of-life assessments were evaluated 12 months after initiation of therapy.

CONCLUSIONS

Laparoscopic myotomy was found to be superior to an endoscopic balloon dilatation strategy in the treatment of achalasia when studied during the first 12 months after treatment.

Health economic evaluation of therapeutic strategies in patients with idiopathic achalasia: results of a randomized trial comparing pneumatic dilatation with laparoscopic cardiomyotomy

BACKGROUND

We have prospectively collected information concerning the costs incurred during the management of patients allocated to either forceful dilatation or to an immediate laparoscopic operation because of newly diagnosed achalasia.

METHODS

Fifty-one patients with newly diagnosed achalasia were randomized to either pneumatic dilatation to a diameter of 30-40 mm or to a laparoscopic myotomy to which was added a posterior partial fundoplication. Follow-ups were scheduled at 1, 3, 6, and 12 months after inclusion. At each follow-up visit a study nurse interviewed the patients regarding symptoms and their quality of life (QoL) and a health economic questionnaire was completed. In the latter questionnaire, patients were asked to report the presence and character of contacts with the healthcare system since the last visit.

RESULTS

In the dilatation group six patients (23%), including the patient who was operated on because of perforation, were classified as failures during the first 12 months of follow-up compared to one (4%) in the myotomy group (p = 0.047). Five of those classified as failures in the dilatation group subsequently had a surgical myotomy and the sixth patient was treated with repeated dilatations. The patient classified as failure in the myotomy group was treated with endoscopic dilatation. The initial treatment cost and the total costs were significantly higher for laparoscopic myotomy compared to a pneumatic dilatation-based strategy (p = 0.0002 and p = 0.0019, respectively). When the total costs were subdivided into the different resources used, we found that the single largest cost item for pneumatic dilatation was that for hospital stay and that for laparoscopic myotomy was the actual operative treatment (operating room time). The cost-effectiveness analysis, relating to the actual treatment failures, revealed that the cost to avoid one treatment failure (incremental cost-effectiveness ratio) amounted to 9239 euros.

CONCLUSION

The current prospective, controlled clinical trial shows that despite a higher level of clinical efficacy of laparoscopic myotomy to prevent treatment failure in newly diagnosed achalasia, the cost effectiveness of pneumatic dilatation is superior, at least when a reasonable time horizon is applied.

Characteristics of timed barium esophagogram in newly diagnosed idiopathic achalasia: clinical and manometric correlates

PURPOSE

To describe timed barium esophagogram (TBE) characteristics in patients with newly diagnosed idiopathic achalasia, and to correlate these with clinical and manometric variables.

MATERIAL AND METHODS

Forty-six consecutive patients with newly diagnosed achalasia were examined with TBE. Esophageal emptying was assessed using the height, area, and volume of the barium column. Subjective evaluation was performed according to a standardized protocol in all patients. Objective diagnostic evaluation included manometry.

RESULTS

At the 1-min time point after contrast ingestion, the static parameters median height, maximum, and mean width of the barium column were 16.0, 4.4, and 3.3 cm, respectively. Emptying, expressed as volume of barium, showed significant inverse correlation with the resting and the maximal relaxing pressure of the lower esophageal sphincter (LES) (R = -0.34 and R = -0.54, respectively). There was also an inverse correlation between emptied volume at TBE and the duration of symptoms (R = -0.36), and between barium column width and postprandial chest pain (R = -0.44).

CONCLUSION

All patients with newly diagnosed achalasia presented with delayed emptying of barium the esophagus at TBE. The estimated emptied volume of barium (related to the ingested volume) correlated inversely with the basal tone and the relaxation pressure of the LES. Including estimation of the volume of emptied barium at TBE resulted in closer correlation with manometric values of LES tone than using the parameters traditionally recorded.

Timed barium esophagogram in the assessment of patients with achalasia: reproducibility and observer variation

SUMMARY. The timed barium esophagogram (TBE) is a further development of the barium swallow, introducing functional and dynamic dimensions to the assessment. The purpose of our study was to assess the day to day variability of TBE parameters when scored in healthy subjects, in untreated and in previously treated patients with confirmed diagnoses of achalasia and to assess the intra- and interobserver agreement. After fasting, the subjects drank 250 mL of low-density barium sulfate suspension. Radiographs of the esophagus were exposed at 1, 2 and 5 min after the start of the barium ingestion. The heights and widths of the barium column and changes in these parameters over time (esophageal emptying) were assessed. Each subject was re-tested after a median time interval of 8 days. Healthy individuals emptied their esophagi effectively and promptly with no significant amount of contrast remaining in the lumen after 2 min. In the achalasia patients all TBE variables differed profoundly compared to the controls. There was an excellent intra- and interobserver agreement for all measured variables. The reproducibility of the static TBE variables from day-to-day was good, but not so for the functional assessment of esophageal emptying, having a correlation coefficient of only 0.50. The usefulness of TBE as a clinical and research tool in achalasia patients requires further evaluation.

MRI combined with MR cholangiopancreatography versus helical CT in the evaluation of patients with suspected periampullary tumors: a prospective comparative study

PURPOSE

To establish the diagnostic accuracy of MRI including MR cholangiopancreatography (MRCP) compared with helical CT in the differentiation of malignant and benign lesions in the periampullary region.

MATERIAL AND METHODS

Fifty-one patients (27 M, 24 F, mean age 66 years, range 39-86 years) with obstructive jaundice and sonographic evidence of intra- and extrahepatic bile duct dilatation (n=31) or suspicion of periampullary tumor, based on previously performed ultrasound and/or CT examination (n=20), were studied. MRI with MRCP and helical CT were reviewed blindly under standardized conditions. Lesion status (differentiation of malignant versus benign) was rated on a 5-point diagnostic confidence scale. Reference standards for comparison were findings at surgery or laparoscopy and/ or the clinical outcome. The predictive value of imaging findings was determined with multivariate logistic regression analysis.

RESULTS

The areas under the receiver operating characteristic curve were 0.96 for MRI with MRCP and 0.81 for CT (P <0.05). Multivariate analysis of eight imaging variables at MRI indicated that a stricture with malignant characteristics at MRCP was the best predictor of malignancy.

CONCLUSION

MRI with MRCP was significantly more accurate than CT in differentiating between malignant and benign lesions in patients with suspected periampullary tumors, mainly due to the information obtained on the MRCP images of the biliary and pancreatic duct anatomy.

MRI combined with MR cholangiopancreatography versus helical CT in the evaluation of patients with suspected periampullary tumors: a prospective comparative study

PURPOSE

To establish the diagnostic accuracy of MRI including MR cholangiopancreatography (MRCP) compared with helical CT in the differentiation of malignant and benign lesions in the periampullary region.

MATERIAL AND METHODS

Fifty-one patients (27 M, 24 F, mean age 66 years, range 39-86 years) with obstructive jaundice and sonographic evidence of intra- and extrahepatic bile duct dilatation (n=31) or suspicion of periampullary tumor, based on previously performed ultrasound and/or CT examination (n=20), were studied. MRI with MRCP and helical CT were reviewed blindly under standardized conditions. Lesion status (differentiation of malignant versus benign) was rated on a 5-point diagnostic confidence scale. Reference standards for comparison were findings at surgery or laparoscopy and/ or the clinical outcome. The predictive value of imaging findings was determined with multivariate logistic regression analysis.

RESULTS

The areas under the receiver operating characteristic curve were 0.96 for MRI with MRCP and 0.81 for CT (P <0.05). Multivariate analysis of eight imaging variables at MRI indicated that a stricture with malignant characteristics at MRCP was the best predictor of malignancy.

CONCLUSION

MRI with MRCP was significantly more accurate than CT in differentiating between malignant and benign lesions in patients with suspected periampullary tumors, mainly due to the information obtained on the MRCP images of the biliary and pancreatic duct anatomy.

Analyses of bronchial bulky DNA adduct levels and CYP2C9, GSTP1 and NQO1 genotypes in a Hungarian study population with pulmonary diseases

Carcinogen-DNA adducts may represent an intermediate end-point in the carcinogenic cascade and may reflect exposure to chemical carcinogens, as well as susceptibility and, ultimately, cancer risk. Interindividual variability in activity of enzymes involved in the metabolism of polycyclic aromatic hydrocarbons to mutagenic diol epoxides may predict adduct levels and, indirectly, lung cancer risk. Using 32P-postlabeling methods, the levels of bulky DNA adducts were determined in macroscopically normal bronchial tissues obtained from resected lobes of 143 Hungarian patients with lung malignancy and other pulmonary conditions. DNA from normal tissue was also evaluated for polymorphisms in cytochrome P450 2C9 (CYP2C9) at two sites, codons 144 (Arg/Cys) and 359 (Ile/Leu), for glutathione S-transferase P1 (GSTP1) at codon 105 and for NAD(P)H:quinone oxidoreductase (NQO1) at codon 187 (Pro/Ser). Using the Mann-Whitney U-test and analysis of variance, levels of adducts were evaluated in relation to variant genotypes, separately for smokers and non-smokers. As previously reported, bulky DNA adduct levels in smokers (n = 104) were estimated to be 54% higher than in non-smokers (n = 39) (8.6 +/- 4.2 versus 5.6 +/- 3.3 per 10(8) nucleotides, respectively, P < 0.01). Adduct levels were 16-29% higher in individuals with the homozygous Ile359/Ile359 CYP2C9 allele than in those heterozygous for the variant allele (Ile359/Leu359) [8.8 +/- 4.3 (n = 84) versus 7.6 +/- 3.5 (n = 20) for smokers and 5.8 +/- 3.5 (n = 32) versus 4.5 +/- 1.3 (n = 7) for non-smokers], although differences were not statistically significant. There were no clear differences in adduct levels in relation to genotypes of NQO1 or GSTP1. Although numbers of patients in this study are large in relation to many studies of carcinogen-DNA adducts, it is still possible that significant differences were not noted for polymorphisms in xenobiotic metabolizing enzymes due to relatively small numbers in stratified data.

Smoking-associated bulky DNA adducts in bronchial tissue related to CYP1A1 MspI and GSTM1 genotypes in lung patients

Relationships between smoking status and levels of bulky DNA adducts were investigated in bronchial tissue of lung patients in relation to their GSTM1 and CYP1A1 MspI genotypes. A total of 150 Hungarian patients undergoing pulmonary surgery were included in the study, 124 with lung malignancies and 26 with non-malignant lung conditions. There were significant relationships between smoking status and bulky DNA adduct levels, as determined by 32P-post-labelling analysis, in macroscopically normal bronchial tissues. There was a highly significant difference in the adduct levels of a combined group consisting of current smokers and short-term ex-smokers (< or = 1 year abstinence) compared with life-time non-smokers and long-term ex-smokers (> 1 year abstinence) (P = 0.0001). The apparent half-life was estimated to be 1.7 years for bulky DNA adducts in the bronchial tissue from ex-smokers. There were no statistically significant correlations between (i) daily cigarette dose and DNA adduct levels in current smokers, (ii) DNA adduct level and histological type of lung cancer, or (iii) GSTM1 and CYP1A1 MspI genotypes and DNA adduct levels after adjustment for either smoking status or malignancy. By multiple logistic regression analysis, smoking and GSTM1 null genotype were found to be risk factors for squamous cell carcinoma. However, bulky DNA adduct levels in bronchial tissue did not appear to be a statistically-significant risk factor for the major histological types of lung cancer.

Multimodality treatment of esophageal disruptions

The treatment of esophageal disruptions has changed since 1981. The value of a more selective assessment in six spontaneous ruptures and 30 mostly intrathoracic (83.4%) esophageal perforations is evaluated in this study. Based on the previous state of the esophagus, the time factor, and type and site of the disruption, reinforced primary repair (by diaphragmatic, muscular, pleural flap, or fundoplication), transhiatal closure, resection, intubation, suture combined with myotomy and fundoplication, esophageal diversion, and transhiatal mediastinal drainage were employed. The overall 30-day hospital mortality was 19.4%. Although these operations were mostly used in late (24 h to 7 months) perforations and ruptures, none of the patients with reinforced repair by autogenous diaphragmatic, muscular, or pleural flaps or fundoplication had fatal outcome for breakdown of the closure. Only patients with renal, cardiac, or multiorgan failure as a consequence of sepsis due to time elapsed before hospital admission died. The key to improve the prognosis of this life-threatening emergency is the more appropriate selection of the primary employed procedure.

Transdiaphragmatic cyst-jejunostomy with Roux-en-Y loop for an exclusively mediastinal pancreatic pseudocyst

In a patient presenting with a roentgenographic retrocardiac density, left pleural effusion and distal oesophageal displacement, echocardiography confirmed presence of a pseudocyst in the posterior mediastinum. Pancreatic origin was suspected. Left thoracolaparotomy revealed the large (900 ml), exclusively mediastinal pseudocyst, surrounding the aorta and adherent to the diaphragm, with high amylase content. Decompression was achieved with a retrocolic and gastric Roux-en-Y loop by transdiaphragmatic cystojejunostomy.

Smoking-related increase in O6-alkylguanine-DNA alkyltransferase activity in human lung tissue

O6-Alkylguanine-DNA alkyltransferase (AGAT) activity was determined in macroscopically normal peripheral lung tissues from 122 patients undergoing lung surgery. AGAT activity of smokers was 1.4-fold higher than that of lifetime non-smokers (P = 0.030). Less than one year of abstinence from smoking did not cause a significant decrease in AGAT activity in former smokers, however, longer abstinence resulted in a decrease in AGAT activity to the level detected in lifetime non-smokers. There was no significant difference between levels of AGAT activity in lung cancer and noncancer patients. The results demonstrate that the level of AGAT activity in human peripheral lung tissue is influenced by smoking habits but does not have a diagnostic correlation to lung cancer.

[Minimally invasive thoracic surgical procedures. Experience with standard video-thoracoscopic and mini-thoracotomy methods]

Experiences based on 75 minimal invasive intrathoracic procedures performed during a one and half--year--period are reported. The standard video thoracoscopic and mini-thoracotomy methods are compared. The possible indications are discussed, and the authors' opinion about the role of these methods in pulmonary resections is presented. They call attention to the consideration of the limits and possibilities of this new technique.

[Possibilities and limitations of minimally invasive methods in thoracic surgery]

First experiences with minimal invasive thoracic surgery are presented. Between November 1991 and September 1992 37 intrathoracic operations--3 lobectomies among them--have been performed by their modified method. A special surgical thoracoscope was inserted through a 6-7 cm-s incision into the thorax. This instrument provides a direct view with excellent distal illumination and it also can be applied by video-thoracoscopic system. It is emphasized that their method needs further development. It's practical value and result depend on the appropriate consideration of possibilities and limits, and on careful selection of the patients.

Determination of smoking-related DNA adducts in lung-cancer and non-cancer patients

Aromatic DNA adduct levels were determined in macroscopically normal bronchial tissues from 98 patients undergoing pulmonary surgery. The mean DNA adduct level for the 45 current smokers was significantly higher than that of the 16 life-time non-smokers. There was a weak association between adduct levels and daily cigarette consumption above 10 cigarettes per day. DNA adduct levels in the 37 former smokers suggested an exponential form of adduct elimination with a rapid initial and a slower later phase after cessation of smoking. There was no quantitative association between bronchial DNA adduct levels and lung cancer.

[Surgical management of mediastinal tumors based on experience with 1000 cases]

One thousand operated mediastinal tumours are analysed. Their characteristic features are discussed and some uncommon manifestations are presented. It is emphasized that in most cases (80-90%) the traditional simple X-ray methods can give a sufficient information for the diagnosis. On the other hand, vascular lesions, cervicomediastinal goiters, dumbbell neurinomas, lymphatic diseases and esophageal lesions should be detected carefully by especial diagnostic methods before surgery because of the different operative tactics and consequences. The diagnosis of the mediastinal neoplasm indicates surgery due to their compressive behaviour.

[Reoperation in thoracic outlet syndrome]

Questions of surgical treatment are dealt with shortly when analyzing reoperations in cases of thoracic outlet syndrome. Transaxillary first rib resection is considered as a favourable solution. Authors believe that in the overwhelming majority of recurrences it is the lack of resection or insufficient resection of the first rib that can be considered as responsible for it. By the way of conclusion the importance of medical gymnastics and physiotherapy to be started in the early postoperative period is pointed out.

Influence of cigarette smoking on the levels of DNA adducts in human bronchial epithelium and white blood cells

The presence of carcinogen-DNA adducts in human tissues is evidence of exposure to carcinogens and may be an indicator of cancer risk. DNA was isolated from non-tumorous bronchial tissue of 37 cigarette smokers, 8 former smokers and 8 non-smokers and analyzed for the presence of aromatic and/or hydrophobic DNA adducts in the 32P-post-labelling assay. Adducts were detected as bands of radioactive material when 5'-32P-labelled deoxyribonucleoside 3',5'-bisphosphates were chromatographed on polyethyleneimine-cellulose tlc plates, and the patterns indicated the formation of adducts by a large number of compounds. Adduct levels detected in DNA from non-smokers, former smokers and current smokers were 3.45 +/- 1.62, 3.93 +/- 1.92 and 5.53 +/- 2.13 adducts/10(8) nucleotides, respectively. The differences in adduct levels between smokers and former and non-smokers were statistically significant (p less than 0.01); and among the smokers, significant correlations were found between adduct levels and both daily cigarette consumption and total cigarette consumption (daily consumption X number of years smoked). DNA was also isolated from the peripheral-blood leukocytes of 31 heavy smokers (greater than 20 cigarettes/day) and 20 non-smokers and analyzed by 32P-post-labelling. Adduct levels in the smokers' samples were not significantly different from levels in the non-smokers' samples (2.53 +/- 1.31 and 2.12 +/- 1.44 adducts/10(8) nucleotides, respectively). Thus, evidence for carcinogen exposure was found in human bronchial epithelium, a target tissue for tobacco-induced tumour formation, but not in peripheral-blood cells, indicating possible limitations in the use of the latter as a surrogate, non-target tissue source of DNA for monitoring human exposure to inhaled carcinogens.

Reasons behind surgical failures in thoracic outlet syndrome

Possible reasons for surgical failures in TOS were investigated. The importance of accurate clinical diagnosis is pointed out and differential diagnostic problems are reported. Transaxillary first-rib resection is recommended, supplemented by further intervention, if necessary. The term "surgical failure" is explained, ways of avoiding intraoperative complications detailed and the importance of complex post-operative treatment emphasized.