Genotype replacement of the human parainfluenza virus type 2 in Croatia between 2011 and 2017 - the role of neutralising antibodies.

Previously we reported on the HPIV2 genotype distribution in Croatia 2011-2014. Here we expand this period up to 2017 and confirm that G1a genotype has replaced G3 genotype from the period 2011-2014. Our hypothesis was that the G1a-to-G3 genotype replacement is an antibody-driven event. A cross-neutralisation with anti-HPIV2 sera specific for either G1a or G3 genotype revealed the presence of genotype-specific antigenic determinants. By the profound, in silico analyses three potential B cell epitopic regions were identified in the hemagglutinin neuraminidase (regions 314-361 and 474-490) and fusion protein (region 440-484). The region identified in the fusion protein does not show any unique site between the G1a and G3 isolates, five differentially glycosylated sites in the G1a and G3 genotype isolates were identified in epitopic regions of hemagglutinin neuraminidase. All positively selected codons were found to be located either in the region 314-316 or in the region 474-490 what indicates a strong positive selection in this region and reveals that these regions are susceptible to evolutionary pressure possibly caused by antibodies what gives a strong verification to our hypothesis that neutralising antibodies are a key determinant in the inherently complex adaptive evolution of HPIV2 in the region.

Factors influencing preclinical in vivo evaluation of mumps vaccine strain immunogenicity.

Immunogenicity testing in animals is a necessary preclinical assay for demonstration of vaccine efficacy the results of which are often the basis for the decision whether to proceed or withdraw the further development of the novel vaccine candidate. However, in vivo assays are rarely, if at all, optimized and validated. Here we clearly demonstrate the importance of in vivo assay (mumps virus immunogenicity testing in guinea pigs) optimization for gaining reliable results and the suitability of Fractional factorial design of experiments (DoE) for such a purpose. By the use of DoE with resolution IV (2IV((4-1))) we clearly revealed that the parameters significantly increasing assay sensitivity were interval between animal immunizations followed by the body weight of experimental animals. The quantity (0 versus 2%) of the stabilizer (fetal bovine serum, FBS) in the sample was shown as non-influencing parameter in DoE setup. However, the separate experiment investigating only the FBS influence, and performed under other parameters optimally set, showed that FBS also influences the results of immunogenicity assay. Such finding indicated that (a) factors with strong influence on the measured outcome can hide the effects of parameters with modest/low influence and (b) the matrix of mumps virus samples to be compared for immunogenicity must be identical for reliable virus immunogenicity comparison. Finally the 3 mumps vaccine strains widely used for decades in the licensed vaccines were for the first time compared in an animal model, and results obtained were in line with their reported immunogenicity in human population supporting the predictive power of the optimized in vivo assay.

Antigenic differences between vaccine and circulating wild-type mumps viruses decreases neutralization capacity of vaccine-induced antibodies.

A recent resurgence of mumps in doubly vaccinated cohorts has been observed, identifying genotype G as the current predominant genotype. In this study, the neutralization efficacy of guinea pig sera immunized with three vaccine viruses: L-Zagreb, Urabe AM9 and JL5, was tested against seven mumps viruses: three vaccine strains and four wild-type strains (two of genotype G, one of genotype C, one of genotype D) isolated during 1998-2011. All sera neutralized all viruses although at different levels. The neutralization efficiency of sera decreases several fold by temporal order of virus isolation. Therefore, we concluded that gradual evolution of mumps viruses, rather than belonging to a certain genotype, results in an antigenic divergence from the vaccine strains that decrease the neutralization capacity of vaccine-induced antibodies. Moreover, the amino-acid sequence alignment revealed three new potentially relevant regions for escape from neutralization, i.e. 113-130, 375-403 and 440-443.

Inventory management.

A critical aspect of blood transfusion is the timely provision of high quality blood products. This task remains a significant challenge for many blood services and blood systems reflecting the difficulty of balancing the recruitment of sufficient donors, the optimal utilization of the donor's gift, the increasing safety related restrictions on blood donation, a growing menu of specialized blood products and an ever-growing imperative to increase the efficiency of blood product provision from a cost perspective. As our industry now faces questions about our standard practices including whether or not the age of blood has a negative impact on recipients, it is timely to take a look at our collective inventory management practices. This International Forum represents an effort to get a snap shot of inventory management practices around the world, and to understand the range of different products provided for patients. In addition to sharing current inventory management practices, this Forum is intended to foster an exchange of ideas around where we see our field moving with respect to various issues including specialty products, new technologies, and reducing recipient risk from blood transfusion products.

Dose dependent effects of standardized nose-horned viper (Vipera ammodytes ammodytes) venom on parameters of cardiac function in isolated rat heart.

Direct, dose dependent effects of the nose-horned vipers (Vipera ammodytes ammodytes) venom on various parameters of cardiac action in isolated rat hearts were examined. Biochemical (protein content, SDS polyacrylamide gel electrophoresis) and biological (minimum haemorrhagic and necrotizing dose and lethal dose (LD(50))) characterization of the venom was performed before testing. The hearts were infused with venom doses of 30, 90 and 150 microg/mL for 10 min followed by 30 min of wash out period. Left ventricular pressure, coronary flow, heart rate, atrioventricular conduction, myocardial oxygen consumption, incidence and duration of arrhythmias were measured and relative cardiac efficiency was calculated. Cardiac CPK, LDH, AST and troponin I were measured as biochemical markers of myocardial damage. The venom caused dose dependent electrophysiological instability and depression of contractility and coronary flow. Effects on the heart rate were biphasic; transient increase followed by significant slowing of the frequency. Relative cardiac efficiency decreased as oxygen consumption remained high relative to the heart rate-contractility product, indicating purposeless expenditure of oxygen and energy. Effects by the dose of 30 microg/mL were highly reversible while the dose of 90 mug/mL caused damages that were mostly irreversible. The dose of 150 mug/mL induced irreversible asystolic cardiac arrest.

The variability of Vipera ammodytes ammodytes venoms from Croatia--biochemical properties and biological activity.

Vipera ammodytes ammodytes venom has been used for many years in Croatia for immunization of horses and production of specific therapeutic anti-venoms. The neutralizing effectiveness of anti-venoms is directly dependent on the properties of the snake venom used for immunization. Therefore, appropriate characterization of the whole venom is necessary prior to use in the immunization procedure. In the course of such analyses, the variability in biochemical properties and biological activity was observed in venoms collected from snakes originating from different parts of Croatia. The venom pools also differed with respect to time of snake collection (1992-2003). Analyses of three samples of whole venom pools were carried out revealing differences in lethal activity (LD50), minimum haemorrhagic dose (MHD), minimum necrotizing dose (MND), phospholipase A2 activity and in anticomplementary activity. SDS-PAGE electrophoretic patterns were similar, but not identical, for all tested venom pools with respect to the number of protein bands detected, but intensity of particular components differed. Preliminary immunogenicity testing in terms of determination of specific antibodies revealed similar immunogenicity and high cross-reactivity for three samples tested.

Intronic polymorphism of tryptophan hydroxylase and serotonin transporter: indication for combined effect in predisposition to suicide.

Indices of disturbed serotonergic neurotransmission are the most robust biological findings in suicide. Tryptophan hydroxylase (TPH) and 5-hydroxytryptamine transporter (5HTt) are the main regulators of 5HT signaling. Owing to the assumed functionality of intronic polymorphisms of TPH (218AC) and 5HTt (VNTR-2) genes, we investigated frequencies of concurrence of the TPH and 5HTt genotypes containing "lower activity" alleles (CC and 1010, respectively), in 192 suicide victims and 377 controls. Significant differences in frequencies of 5HTt and TPH genotype combinations were found between suicide victims and control subjects (p = 0.0156), with a clear dose-effect of the suspected ("lower activity") genotypes (p = 0.0046). Concurrent presence of the two, allegedly transcriptionally less active, variants of these genes seems to be in some kind of relation to the increased susceptibility to suicide.

Variations of ochratoxin A concentration in the blood of healthy populations in some Croatian cities.

The nephrotoxic mycotoxin ochratoxin A (OTA), a common contaminant of cereals, has been implicated in the etiology of endemic nephropathy. It was also frequently found in low concentrations in blood of healthy populations in countries where endemic nephropathy is not known. However, data on regional and seasonal differences in the frequency and concentration of OTA in human blood are scarce. In June, September and December 1997, and March 1998, about 50 human blood samples were collected randomly from blood donors for blood banks in the Coatian cities of Osijek, Rijeka, Split, VaraZdin and Zagreb. OTA was measured in the total of 983 samples using an HPLC technique with fluorescent detection. The daily intake of OTA was estimated from the mean concentration found in different cities and at different times of year. Samples containing OTA above the detection limit (0.2 ng/ml of plasma) were found in populations from all Croatian cities at all collecting periods. The highest frequency (59%) of samples containing OTA above the detection limit and the highest mean concentration (0.39 ng/ml) were found in June. Both the frequency and the mean concentration were lowest in all samples in December (36% and 0.19 ng OTA/ml, respectively). Osijek was the city with the highest frequency of OTA-positive samples (81%) and the highest mean OTA concentration (0.56 ng/ml). The total mean concentration of OTA in blood of healthy population in Croatia is lower (0.30 ng/ ml) than the mean concentration in European countries as a whole (0.90 ng/ml). The estimated daily intake, calculated from the mean concentration in all blood samples, is 0.40 ng OTA/kg body weight, which is much lower than that proposed by World Health Organization as the tolerable daily intake (16.0 ng/kg body weight). Healthy populations of Croatia are exposed to low, but seasonally and regionally variable amounts of OTA.

Acute pancreatitis in the Zabok General Hospital.

Acute pancreatitis is an acute disease of the pancreas due to the organ autodigestion. The disease is still burdened with numerous complications and quite frequently with lethal outcome, in spite of the sophisticated diagnostic and therapeutic methods currently available. The disease has a benign course in a majority of patients (80%), however, in the remaining 20% it assumes a malignant course with the development of massive necroses of the pancreatic and peripancreatic tissues, infection, hemorrhage, and endogenous intoxication with lesions of the lungs, kidneys, heart and liver. The biliary tract disease plays the major role in the etiology of acute pancreatitis (80%), followed by alcoholism (10% to 15%). This differs from the experience acquired at the Zabok General Hospital, where an almost identical incidence of biliary and ethylic etiology was recorded. Other, less common causes include post-traumatic, postoperative, infective and hormonal (hyperparathyroidism) etiology. In some cases, the cause of acute pancreatitis remains unknown. The disease shows a female predominance, which results from the higher prevalence of cholelithiasis in women than in men. Anatomically, there are two main forms of acute pancreatitis, interstitial or edematous form, and hemorrhagic necrotizing form. The interstitial or edematous form of acute pancreatitis is characterized by edema (exudation) of the pancreatic interstitium. The hemorrhagic necrotizing form of acute pancreatitis is characterized by autodigestion of a minor or major portion of the pancreas and peripancreatic tissues. The diagnosis of acute pancreatitis may initially pose a considerable problem. Decision on the mode of treatment should primarily be based on the clinical picture and supported by relevant laboratory parameters and other diagnostic procedures (ultrasonography, computed tomography). Conservative therapy is indicated for the edematous form of acute pancreatitis, whereas operative treatment is as a rule used for the necrotizing form of acute pancreatitis. Secondary bacterial contamination of the necrotic foci with the development of septic complications occurs in more than 50% of patients with the necrotizing form of acute pancreatitis, and is an absolute indication for surgical intervention. The modes of treatment used in 57 patients admitted for acute pancreatitis during the 1996-1999 period are described. Cholelithiasis was the cause of acute pancreatitis in 28 (49.1%), and alcoholism in 29 (50.9%) patients. Conservative treatment was used in 41 (72%) patients. Sixteen (28%) patients underwent operative treatment. Explorative laparotomy and drainage were performed in four patients, and explorative laparotomy, necrectomy, sequestrectomy and drainage with two or more drains in 11 patients. Cholecystectomy and T drainage along with necrectomy and drainage were performed in one patient. There were 12 (21%) patients with the most severe form of acute pancreatitis. Nine of these patients were operated on (necrectomy drainage) between day 6 and 10 of the disease. Two of these patients had to be reoperated on within a month, due to necrosis and abscess recurrence. Three of the 12 patients with the severe form of acute pancreatitis received conservative therapy. Fifteen patients were operated on 8-10 weeks after acute pancreatitis had subsided. Pseudocysts developed in three patients. These patients were operated on 6-8 weeks from the onset of disease, with internal drainage via isolated small intestine flexure performed in all of these patients. The mean duration of intensive care unit stay for all patients with acute pancreatitis was 20.6 days. Four of 57 patients hospitalized for acute pancreatitis died. The mortality rate in the group of patients with the severe form of acute pancreatitis (n = 12) was 33%. Complications developed in 50% of operatively treated patients.

[Contribution to the nomenclature of variations of the cystic artery]. / Ein Beitrag zur Nomenklatur der Variationen der Arteria cystica.

INTRODUCTION: Safe procedures for laparoscopic cholecystectomy demand good knowledge of the anatomy of the terminal part of the cystic artery and its variations, and also precise dissection in and around the hepatobiliary triangle. METHOD: Good laparoscopic visualisation enables recognition of the variation of the cystic artery. Our observations are based on 1000 cholecystectomies. RESULTS: We have described and named variations of the terminal part of the cystic artery. Group I comprises the five variations of the cystic artery within the hepatobiliary triangle: (a) "normal" position; (b) frontal cystic artery; (c) backside; (d) multiple; (e) short cystic artery that arises from an aberrant right hepatic artery. Group II consists of variations of the cystic artery that approach--the gallbladder beyond the hepatobiliary triangle: (a) "low-lying"; (b) transhepatic; (c) "recurrent" cystic artery. CONCLUSION: Our classification is simple and easy to memorize and will considerably facilitate safe laparoscopic cholecystectomy.

Dynamics of serum hepatitis C virus load and quasispecies complexity during antiviral therapy in patients with chronic hepatitis C.

BACKGROUND: Hepatitis C virus (HCV) infection is a dynamic process during which viral genetic variants continuously develop as a result of the virus adaptation to the host's immune system. The level of viremia and the complexity of the hypervariable region 1 (HVR 1) quasispecies of hepatitis C virus during antiviral therapy reflect the dynamic balance between the viral and host components in response to therapy. OBJECTIVE: The aim of the study was to evaluate the dynamics of HCV viremia and the complexity of the HVR 1 quasispecies during the induction phase of a triple combination therapy regimen in nonresponders to earlier anti-HCV treatment. STUDY DESIGN: Ten patients with chronic hepatitis C undergoing antiviral combination therapy with interferon-alpha, ribavirin, and amantadine were studied. The serum HCV RNA level was monitored by a quantitative RT-PCR assay up to 3 months after start of treatment. The HVR 1 quasispecies complexity was analysed by an "in house" nested RT-PCR mediated single-strand conformation polymorphism (SSCP) assay. RESULTS: Baseline serum HCV RNA levels ranged from 1.94x10(6) to 5.53x10(6) copies/ml. In all patients, HCV subtype 1b was found. At the start of therapy, the SSCP assay revealed a high complexity pattern (at least six SSCP bands) in all patients. None of the patients responded within 4 weeks of treatment, however, the serum HCV RNA level decreased by one to two logs in eight patients. At week 4 after start of treatment, there was a decrease of SSCP bands in five patients. In four patients, SSCP bands remained unchanged and in one patient SSCP bands increased. At month 3 after start of treatment, serum HCV RNA was not detectable in one patient. CONCLUSION: Because of the low number of patients involved in this study, prediction of therapeutical success based on the quasispecies complexity was not possible. Larger studies are urgently needed.

Gastrointestinal pseudo-obstruction: report of a patient with postoperative pseudo-obstruction.

Postoperative pseudo-obstruction is a rare state of protracted gastrointestinal paresis that may progress to paralysis without the presence of obstructive lesions. Pseudo-obstruction is usually, but not exclusively, associated with an abdominal operative procedure (laparotomy), however, it may occasionally occur following extra-abdominal operations. As differentiated from the usual, 'physiologic'postoperative paresis, pseudo-obstruction persists for more than 7 days. The pathogenesis of postoperative pseudo-obstruction is complex and as yet partially unknown. Whereas the 'physiologic' postoperative gastrointestinal paresis includes short-term functional cholinergic depression of the visceral organs, in pseudo-obstruction focal lesions in the region of Auerbach's plexus, manifesting as visceral neuromyopathy, are involved. That is why the 'physiologic' postoperative paresis never transforms into paralytic ileus, while in pseudo-obstruction such a risk is potentially involved. The treatment for pseudo-obstruction is as a rule conservative. Surgical treatment (cecostomy) is rarely required. Colonoscopic decompresive suction is usually enough to eliminate the risk of colon rupture due to extensive distention by fast growing meteorism. A patient with postoperative pseudo-obstruction is presented.

Hypervariable region 1 of hepatitis C virus genome and response to interferon therapy.

The relationship between the complexity of the hypervariable region 1 (HVR1) quasispecies of hepatitis C virus (HCV) and responsiveness to interferon-alpha (IFN) therapy was studied in patients with chronic hepatitis C. Twelve HCV-RNA-positive patients were treated daily with high dose IFN and ribavirin for 4 weeks, and then with IFN 3 MIU (Million International Units) TIW (three times per week) and ribavirin for 6 months. The HVR1 quasispecies complexity was analyzed by nested polymerase chain reaction-mediated single-strand conformation polymorphism (SSCP). The baseline HCV-RNA levels in the study group ranged from 10(6) to 10(7) copies/ml. All patients exhibited HCV genotype 1 b. Initial SSCP analysis revealed four (33.3%) patients with a low complexity pattern (SSCP bands < or =4) and eight (66.6%) patients with high complexity pattern (SSCP bands >4). After 4 weeks of IFN therapy, one patient became HCV negative, and among those remaining positive, the HCV-RNA levels decreased by 2 to 3 logs and the number of SSCP decreased by 2 to 3 bands per sample. After 6 months of IFN therapy, five (41.7%) patients became HCV-RNA-negative. Seven (58.3%) patients did not respond to IFN therapy with sustained viral load from 10(3) to 10(5) copies/ml, and high complexity SSCP patterns. Our data support the HVR quasispecies complexity to be an independent predictive factor for IFN responsiveness in patients infected with HCV.

Decreasing risk of viral transfusion-transmitted diseases in Croatia.

AIM: To assess the risk of viral transfusion-transmitted infections in Croatia. METHODS: The following parameters were analyzed: frequency of blood donations repeatedly reactive for HBsAg and anti-HCV (1993-1999); blood donations confirmed positive for HBsAg and anti-HCV (1997-1999), anti-HIV1/2, and syphilis reactivity (1993-1999); number of registered patients with hepatitis B and C; transfusion-associated hepatitis B and hepatitis C; and frequency of HBV, HCV and HIV markers in patients with congenital bleeding disorders (1993-1998). RESULTS: The frequency of repeatedly reactive HBsAg and anti HCV markers and confirmed positive HBsAg, anti-HCV, and syphilis markers in donors blood decreased during the study, whereas the frequency of anti-HIV1/2 positivity did not change. The frequency of confirmed positive donors in 1999 was 0.068% for HBsAg, 0.035% for anti HCV, 0.002% for anti HIV1/2, and 0.0056% for syphilis. The number of patients with hepatitis B, hepatitis C, and transfusion-associated hepatitis B and C steadily decreased during the 1993-1998 period. The number of transfusion-associated hepatitis patients leveled off in 1997. From the beginning of the follow-up of AIDS patients in 1987, only 7 (2%) of hemophiliacs have been HIV-infected, all before 1990 and due to non-inactivated coagulation factor concentrates. There were no cases of transfusion-associated HIV2 infection in patients with congenital bleeding disorders or transfusion-associated HIV1 infection through transfusion of labile blood components. CONCLUSION: The safety of transfusion therapy in Croatia has improved, and the present risks of viral transfusion transmitted diseases are very low.

Physiological characteristics of platelet/circulatory serotonin: study on a large human population.

The aim of this work was the study of platelet/circulatory serotonin (5-hydroxytryptamine, 5-HT), specifically alternative ways of its measurement and main physiological characteristics. The study was performed on a large human population (N=500) of blood donors of both sexes over the course of a longer time period (17 months). Owing to the heterogeneity in measurement of circulatory serotonin encountered in the literature, three ways of expression were comparatively studied: per unit number of platelets, per unit mass of platelet protein and per unit volume of whole blood. Results demonstrated unimodal distribution of individual frequencies of platelet/circulatory serotonin in the human population with the mean values of 579+/-169 ng 5-HT/10(9) platelets; 332+/-89.9 ng 5-HT/mg protein and 130+/-42.3 ng 5-HT/ml blood (mean+/-S.D.). A progressive decrease of serotonin level with age (18-65 years) was demonstrated, reaching statistical significance between the extreme age groups. No significant differences in the serotonin level between the sexes were observed. No seasonal oscillations in platelet/circulatory serotonin were found. Platelet serotonin demonstrated intra-individual stability over time. Finally, regarding the methodology of measurement, our results demonstrated a good correlation among the above-mentioned ways of expression of platelet/circulatory serotonin. This indicates the possibility of intercomparison of the literature reports expressing this physiological parameter either as 5-HT concentration in platelets or as 5-HT level in the circulation.

Posttraumatic stress disorder and platelet serotonin measures.

The role of serotonin (5HT) in the pathophysiology of posttraumatic stress disorder (PTSD) has been suggested by the overlap in clinical symptoms between PTSD and psychiatric conditions in which a serotonin dysfunction is implicated, as well as by the therapeutic efficiency of 5HT-related drugs (antidepressants, selective serotonin reuptake inhibitors and monoamine oxidase inhibitors) in alleviating symptoms in PTSD. In the present study, the blood platelet, which has been proposed as a peripheral model for the central serotonergic neurons, has been used to search for alterations in 5HT mechanisms in PTSD. Platelet serotonin level and kinetics of serotonin transporter and monoamine oxidase (MAO-B) were assessed in 63 combat-related PTSD patients and 43 sex and age-matched control subjects. A significant reduction in maximal velocity of platelet MAO-B (approx. 30%), with no changes in the enzyme affinity was observed in our patient sample. Conversely, no alterations in kinetic parameters (V(max), K(m)) of platelet serotonin transporter, as well as in platelet 5HT level, were found in the PTSD group.

Laparoscopic visualization of the cystic artery anatomy.

Uncontrolled bleeding from the cystic artery and its branches is a serious problem that may increase the risk of intraoperative lesions to vital vascular and biliary structures. On laparoscopic visualization anatomic relations are seen differently than during conventional surgery, so proper knowledge of the hepatobiliary triangle anatomic structures under the conditions of laparoscopic visualization is required. We present an original classification of the anatomic variations of the cystic artery into two main groups based on our experience with 200 laparoscopic cholecystectomies, with due consideration of the known anatomicotopographic relations. Group I designates a cystic artery situated within the hepatobiliary triangle on laparoscopic visualization. This group included three types: (1) normally lying cystic artery, found in 147 (73.5%) patients; (2) most common cystic artery variation, manifesting as its doubling, present in 31 (15.5%) patients; and (3) the cystic artery originating from the aberrant right hepatic artery, observed in 11 (5.5%) patients. Group II designates a cystic artery that could not be found within the hepatobiliary triangle on laparoscopic dissection. This group included two types of variation: (1) cystic artery originating from the gastroduodenal artery, found in nine (4. 5%) patients; and (2) cystic artery originating from the left hepatic artery, recorded in two (1%) patients.

Ochratoxin A in blood of healthy population in Zagreb.

Healthy blood donors from the city of Zagreb were checked for the presence of a nephrotoxic mycotoxin ochratoxin A (OTA) in the plasma. Samples of blood were collected in June, September, and December 1997, and March 1998, totalling 200 or 50 in each round. The concentrations of OTA were measured using high pressure liquid chromatography (HPLC) method (detection limit 0.2 ng OTA/ml of plasma). The frequency of OTA-positive samples (> 0.2 ng/ml of plasma) showed significant seasonal variation (P < 0.001). The frequency of OTA-positive samples was the highest in March (65%) and it gradually decreased towards December (12%). The high frequency of positive samples coincided with seasons favouring growth of moulds and production of toxins. The daily intake of OTA by healthy persons in Zagreb was estimated from the mean concentration of OTA in samples collected during the whole year (0.19 ng OTA/ml plasma). The estimated daily intake was 0.26 ng/kg b.w., that is, substantially below the tolerable daily intake proposed by World Health Organization (16.0 ng/kg b.w.).

Biliary duct reoperations.

Conventional operations for cholelithiasis are rarely associated with postoperative complications. However, when the complications do occur, they are frequently life threatening and require reoperation. These reoperations are associated with a considerably higher risk than primary procedures, and require maximal caution and experience from the surgeon. Reoperations are performed in anatomically altered conditions, and in a patient psychically and physically exhausted and in fear from repeat procedure. Therefore, it is of utmost importance for each primary operation including conventional procedure for cholelithiasis to be carried out at a high professional level, using all technologic achievements available that facilitate and improve the surgeon's work safety. In this way, the need of undesired and hazardous reoperations is minimized. The rate of and indications for reoperation in 530 patients operated on by the conventional procedure for cholelithiasis during the 1994-1999 period are presented.