Widespread breakdown in masting in European beech due to rising summer temperatures

Climate change effects on tree reproduction are poorly understood, even though the resilience of populations relies on sufficient regeneration to balance increasing rates of mortality. Forest-forming tree species often mast, i.e. reproduce through synchronised year-to-year variation in seed production, which improves pollination and reduces seed predation. Recent observations in European beech show, however, that current climate change can dampen interannual variation and synchrony of seed production and that this masting breakdown drastically reduces the viability of seed crops. Importantly, it is unclear under which conditions masting breakdown occurs and how widespread breakdown is in this pan-European species. Here, we analysed 50 long-term datasets of population-level seed production, sampled across the distribution of European beech, and identified increasing summer temperatures as the general driver of masting breakdown. Specifically, increases in site-specific mean maximum temperatures during June and July were observed across most of the species range, while the interannual variability of population-level seed production (CVp) decreased. The declines in CVp were greatest, where temperatures increased most rapidly. Additionally, the occurrence of crop failures and low seed years has decreased during the last four decades, signalling altered starvation effects of masting on seed predators. Notably, CVp did not vary among sites according to site mean summer temperature. Instead, masting breakdown occurs in response to warming local temperatures (i.e. increasing relative temperatures), such that the risk is not restricted to populations growing in warm average conditions. As lowered CVp can reduce viable seed production despite the overall increase in seed count, our results warn that a covert mechanism is underway that may hinder the regeneration potential of European beech under climate change, with great potential to alter forest functioning and community dynamics.

The low survival rate of European hare leverets in arable farmland: evidence from the predation experiment

The low survival rate of leverets may significantly contribute to steep population declines and slow recovery of European hares (Lepus europaeus). However, the leveret survival rate in farmlands with different landscape structures is poorly understood, and the existing evidence comes mainly from Western Europe. In this study, we explored the survival of leveret hare dummies along linear semi-natural habitats in homogeneous Central European arable farmland during the main part of the European hare reproduction period (March-April) in 2019 and 2020. The survival rate of hare leverets during the 14-day period was only 22.2%, and all predation events were recorded during the first six days of the experiment. Mammalian predators were responsible for 53.1% of predation events, avian predators for 40.8%, and agricultural operations for 6.1%. The red fox (Vulpes vulpes) was the dominant predator in our study area and was the primary cause of leveret dummy mortality (32.7%), but it also had the highest use-intensity and visit frequency of all of the study plots. Predation by avian predators was associated with patches of lower vegetation height and cover (such as plowed fields) and during daylight hours, whereas the opposite was true for mammalian predators. We propose that improving the habitat quality of arable landscapes by increasing the proportion and quality of extensively used non-farmed habitats (e.g., set-asides, wildflower areas, extensive meadows, fallow land, and semi-natural habitats on arable land) providing cover and shelter for leverets could be an effective management measure for reducing predation risk on leverets.

Silvicultural Practices for Diversity Conservation and Invasive Species Suppression in Forest Ecosystems of the Bundala National Park, Sri Lanka

Forest ecosystems in Sri Lanka are under pressure from intensive human activity and climate change. Invasive species are one of the greatest threats to autochthonous species and ecosystems. In Bundala National Park of Sri Lanka, there are efforts to control and limit the spreading of unwanted invasive Prosopis juliflora (Sw.) DC. and Opuntia dillenii (Ker-Gawl.) Haw., which poses a significant risk to natural ecosystem conservation. Nine different treatment variants (four replications) were used to test which management approach provides the control of Prosopis juliflora. This research is based on nine repeated measurements from 2017 to 2021 on 36 permanent research plots (each 625 m2) with 27 observed plant species and a total of 90,651 recorded plant individuals. The results confirmed that the dynamics of species richness, heterogeneity, and evenness showed significant differences between treatments during the five years of dynamics. The lowest species diversity was found in the control variant, followed by treatments based on the hard pruning and thinning of Prosopis juliflora trees. In contrast, strategies emphasizing the complete uprooting of Prosopis juliflora trees, replanting, and support of the natural regeneration of native species showed high species diversity and a high overall number of plant species. Generally, treatments had a significant effect on species diversity and the number of individuals of Prosopis juliflora, while changes in the overall number of plant species were more affected by time and succession. Silvicultural treatments including pruning, uprooting, and thinning have proven to be essential tools for nature conservation across various sites, aimed at enhancing habitat diversity in the face of ongoing climate change.

European forests under global climate change: Review of tree growth processes, crises and management strategies

The ongoing global climate change is challenging all sectors, forestry notwithstanding. On the one hand, forest ecosystems are exposed to and threatened by climate change, but on the other hand, forests can influence the course of climate change by regulating the water regime, air quality, carbon sequestration, and even reduce climate extremes. Therefore, it is crucial to see climate change not only as a risk causing forest disturbances and economic consequences but also as an opportunity for innovative approaches to forest management, conservation, and silviculture based on the results of long-term research. We reviewed 365 studies evaluating the impact of climate change on European forest ecosystems, all published during the last 30 years (1993-2022). The most significant consequences of climate change include more frequent and destructive large-scale forest disturbances (wildfire, windstorm, drought, flood, bark beetle, root rot), and tree species migration. Species distribution shifts and changes in tree growth rate have substantial effects on ecosystem carbon storage. Diameter/volume increment changed from -1 to +99% in Central and Northern Europe, while it decreased from -12 to -49% in Southern Europe across tree species over the last ca. 50 years. However, it is important to sharply focus on the causes of climate change and subsequently, on adaptive strategies, which can successfully include the creation of species-diverse, spatially and age-wise structured stands (decrease drought stress and increase production), prolongation of the regenerative period, or the use of suitable introduced tree species (e.g., Douglas fir, black pine, and Mediterranean oaks). But the desired changes are based on increasing diversity and the mitigation of climate change, and will require significantly higher initial costs for silviculture practices. In conclusion, the scope and complexity of the topic require further comprehensive and long-term studies focusing on international cooperation. We see a critical gap in the transfer of research results into actual forest practice, which will be the key factor influencing afforestation of forest stands and forest growth in the following decades. What our forests will look like for future generations and what the resulting impact of climate change will be on forestry is in the hands of forest managers, depending on supportive forestry research and climate change policy, including adaptive and mitigation strategies.

New agri-environmental measures have a direct effect on wildlife and economy on conventional agricultural land

The objective of this article is to evaluate economic profits along with return on investment and also the impact of newly designed agri-environmental measures (AEM) on the presence of bioindicator species-European hare and roe deer-in comparison to conventionally cultivated agricultural land. The abundance of European hare was, on average, 4.5-6.7 times higher on AEM compared to the standard agricultural regime and 3.5-6.4 times higher in the case of roe deer in 2020 and 2021. From an economic point of view, the highest incomes were found for extensive orchard alleys and standard conventional crops-wheat and rapeseed rotation. The cash flow from extensive orchard was 4.3 times larger and wheat and rapeseed were 3.5 times larger than from the clover grass mixture. Moreover, the lowest value of operational expenses was found in the case of extensive orchard alleys. The payback period ranged from 16.02 years (wheat and rapeseed rotation) to 53.6 years (clover grass mixture). It is crucial not to assess the economic parameters separately but optimize them with sustainable wildlife management and other benefits that provide ecological and efficient directions of AEM for future generations. However, the performed economic analysis highlights the significantly lower incomes of most components of AEM. We see a principal issue of AEMs usage in the lack of strong incentives for farmers to maximize conservation outcomes. Therefore, the AEMs are often placed in locations with presumed low agriculture profit, which is often related to insignificant conservation effects. Thus, the incomparable AEMs profitability compared to conventional agriculture has to be reflected by the agricultural policy at the European Union level and subsidy policy of particular member states.

Evaluation of Spatio-Temporal Patterns of Predation Risk to Forest Grouse Nests in the Central European Mountain Regions

We evaluated the spatiotemporal patterns of predation risk on black grouse nests using artificial nests that were monitored by camera traps in mountain areas with a small extant (Ore Mts.) and already extinct (Jeseníky Mts.) black grouse population. The overall predation rate of artificial nests was 56% and we found significant differences in survival rate courses over time between both study areas (68% Ore Mts. vs. 41%, Jeseníky Mts.). Within the time required for successful egg incubation (25 days), nest survival probability was 0.32 in the Ore Mts. and 0.59 in Jeseníky Mts. The stone marten (Martes foina) was the primary nest predator in both study areas (39% in total), followed by common raven (Corvus corax, 25%) and red fox (Vulpes vulpes, 22%). The proportion of depredated nests did not differ between habitat types (i.e., open forest interior, clearing, forest edge), but we recorded the effect of interaction of study area and habitat. In Ore Mts., the main nest predator was common raven with seven records (37%). The Eurasian jay (Garrulus glandarius) was responsible for most predation attempts in Jeseníky Mts. (five records, i.e., 83%), while in the Ore Mts., most predation attempts were done by red fox (six records, i.e., 38%).

Wild boar deathbed choice in relation to ASF: Are there any differences between positive and negative carcasses?

African swine fever (ASF) is a fatal, infectious disease affecting wild boars and domestic pigs, mostly resulting in their deaths. Previous studies showed that carcasses of infected wild boars pose a serious threat for ASF virus transmission and leaving of dead bodies in the environment enables persistence of the disease in the given affected area. Therefore, the prompt finding and removal of the carcasses is crucial for effective ASF control. This study reveals habitat preferences of ASF-positive wild boars for their deathbeds, which could greatly improve the effectivity in the search for infected carcasses. The vast majority (71%) of carcasses were found in forests (although forests occupy only 26.6% of the high-risk area - Zlin region, Czech Republic), especially in young forest stands; 91.3% of infected wild boar carcasses, which were found in forests, were in stands of up to 40 years of age, where infected individuals search for calm and quiet places. The preference of younger forest stands is significantly higher for infected individuals (p < 0.001). On meadows, infected individuals preferred a higher herb layer (p = 0.002) compared to non-infected individuals. A higher preference of places more distant from roads and forest edges was observed for the infected individuals as well (p < 0.001 in both cases). No differences in deathbed habitat preference were observed between selected sex-age categories. The distance between carcasses and water source was observed to be dependent on current mean temperature. Carcasses were found closer to the water sources at higher mean temperature. Because of the comparable character of the landscape, presented models are applicable across Central Europe and have the potential to greatly facilitate the search for infected carcasses.

Roe deer (Capreolus capreolus) mortality in relation to fodder harvest in agricultural landscape

In the agricultural landscape, thousands of animals are killed yearly as a result of agricultural machinery innovation, mostly because of a higher harvesting speed and wider cutting bars. Harvesting machines besides predation by red fox (Vulpes vulpes L.) on roe deer (Capreolus capreolus L.) in the intensively managed cultural landscape are the most crucial factor in fawn mortality. This article offers an evaluation of the mostly used preventive methods, which aim to drive roe deer does along with their fawns out of fodder meadows prepared for harvest in the Czech Republic. Evaluation of efficiency and effectiveness of the different methods was made based on the questionnaire survey published in a professional hunting journal. The assessment of responses from a survey was followed by a field-based investigation conducted before fodder harvesting. The devices studied for efficiency were acoustic, optical and scent deterrents in comparison to the traditional search method combined with volunteers and hunting dogs. The results show differences in the number of fawns saved per hectare. A significant difference was found only between the optical deterrent method (0.4 fawns saved per hectare) and traditional search method (0.09 fawns saved per hectare). This study found no substantial difference among various deterring devices in terms of their effectiveness in reducing the mortality of roe deer fawns. Thus, it is important to explore the innovative methods in the future that can work most effectively for saving not only deer fawns, but also other game animals in the cultural landscape.

Afforested farmland vs. forestland: Effects of bark stripping by Cervus elaphus and climate on production potential and structure of Picea abies forests

The aim of this study was to evaluate (1) effects of bark stripping and climatic factors on radial growth of Picea abies /L./ Karst., (2) production and structural differences between stands established on the forestland and abandoned farmland (afforested farmland–henceforth, farmland), and (3) interaction among the losses caused by ungulate damages, production, diversity, and soil types. Data acquired from four permanent research plots (PRPs) located on the forestland and eight PRPs on the farmland were used. A number of tree- and stand-level models, stand structural indices, tree-rings, and climate characteristics were analysed to evaluate the hypotheses. The results show significantly higher means of DBH, tree height and basal area on the forestland compared to those on the farmland. There was a larger mean standing stem volume on the forestland (466 m³ ha^–1) compared to farmland (770 m³ ha^–1). Significant difference was observed between the mean DBH and mean stem volume of healthy trees compared to those of the trees with substantial damage (girth damage >1/3 of stem circumference). A greater extent of the girth damage was found on 86% trees on the farmland, while 54% damage on the forestland. About 62% bark-strip damage was further deteriorated by rot infection on the farmland, while on the forestland such an infection was only for 39% trees. The precipitation significantly positively affected the radial growth of trees that were largely affected by ungulate damages on the farmland.

Windbreak Efficiency in Agricultural Landscape of the Central Europe: Multiple Approaches to Wind Erosion Control

Windbreak is one of the key factors for making the agriculture systems successful through reduced wind erosion, improved microclimate, increased biodiversity, and production potentiality of timber and agricultural crops. Even though windbreak occupies only a small part of agricultural landscape, its advantages on the ecological and economical perspective are quite high. This study evaluated the effects of three windbreak types on the wind erosion control in relation to their structural diversities, wind-speed reduction, and optical porosities in the central part of the Czech Republic. Diversity in the windbreak was evaluated based on its species diversity, vertical structure, spatial pattern, and complexities. Wind speed was measured at the different distances on the leeward side of the windbreak and one station placed on the windward side as a control. Windbreak characteristics were described by terrestrial photogrammetry method using the values of optical porosity. The timber volume of the windbreaks with rich biodiversity species ranged from 224 to 443 m³ ha^-1height of the windbreak on the. Results of the windbreak efficiency showed significantly closer relationship between optical porosity and structural indices. The optical porosity significantly correlated with wind-speed reduction, especially in the lower part of the windbreak. A significant dependency of the windbreak efficiency on the tree dominant height was also observed for each windbreak type. The most significant effect on the wind-speed reduction in terms of structural indices had total diversity index and Arten-profile index describing vertical structures, which are recommended together with the optical porosity to evaluate the windbreak efficiency in controlling wind erosion.

Modelling individual tree height to crown base of Norway spruce (Picea abies (L.) Karst.) and European beech (Fagus sylvatica L.)

Height to crown base (HCB) of a tree is an important variable often included as a predictor in various forest models that serve as the fundamental tools for decision-making in forestry. We developed spatially explicit and spatially inexplicit mixed-effects HCB models using measurements from a total 19,404 trees of Norway spruce (Picea abies (L.) Karst.) and European beech (Fagus sylvatica L.) on the permanent sample plots that are located across the Czech Republic. Variables describing site quality, stand density or competition, and species mixing effects were included into the HCB model with use of dominant height (HDOM), basal area of trees larger in diameters than a subject tree (BAL- spatially inexplicit measure) or Hegyi’s competition index (HCI—spatially explicit measure), and basal area proportion of a species of interest (BAPOR), respectively. The parameters describing sample plot-level random effects were included into the HCB model by applying the mixed-effects modelling approach. Among several functional forms evaluated, the logistic function was found most suited to our data. The HCB model for Norway spruce was tested against the data originated from different inventory designs, but model for European beech was tested using partitioned dataset (a part of the main dataset). The variance heteroscedasticity in the residuals was substantially reduced through inclusion of a power variance function into the HCB model. The results showed that spatially explicit model described significantly a larger part of the HCB variations [R²_adj = 0.86 (spruce), 0.85 (beech)] than its spatially inexplicit counterpart [R²_adj = 0.84 (spruce), 0.83 (beech)]. The HCB increased with increasing competitive interactions described by tree-centered competition measure: BAL or HCI, and species mixing effects described by BAPOR. A test of the mixed-effects HCB model with the random effects estimated using at least four trees per sample plot in the validation data confirmed that the model was precise enough for the prediction of HCB for a range of site quality, tree size, stand density, and stand structure. We therefore recommend measuring of HCB on four randomly selected trees of a species of interest on each sample plot for localizing the mixed-effects model and predicting HCB of the remaining trees on the plot. Growth simulations can be made from the data that lack the values for either crown ratio or HCB using the HCB models.

Severe Cryptogenic Multifocal Ulcerous Stenosing Enteritis. A Report of Three Cases and Review of the Literature

Cryptogenic multifocal ulcerous stenosing enteritis (CMUSE) is a rare condition characterised by chronic or relapsing moderate ileous episodes resulting from multiple small intestinal strictures, multiple shallow ulcers of the small bowel and favourable therapeutical effect of glucocorticosteroids. The aim of this paper was to evaluate three cases of CMUSE diagnosed within 10 years at a tertiary gastroenterology centre. Three females (35, 50, 60 years) were presented with colicky pain, repeated moderate ileous episodes and weight loss. Multiple fibrous strictures and ulcers of the small bowel were found. All three patients responded to glucocorticosteroid treatment. Tandem tight jejunal stenoses were dilated endoscopically by means of double balloon enteroscopy. In conclusion, CMUSE should always be considered when chronic moderate ileous episodes and multiple small intestinal strictures and ulcers of uncertain aetiology are found. Double balloon enteroscopy enables precise diagnostic work, possible endoscopic treatment of stenoses, may obviate the need for surgery and prevent excessive small bowel resections.

Inverted Meckel's diverticulum with ectopic pancreatic tissue as a source of severe gastrointestinal bleeding

INTRODUCTION

Meckel's diverticulum is the most common congenital anomaly of the gastrointestinal tract. Authors present a 67-year-old woman treated for iron deficiency anemia for the past 5 years. Suddenly, her disease was presented with painless severe gastrointestinal bleeding (fresh melena). Inverted Meckel's diverticulum with ectopic pancreatic tissue as a source of severe gastrointestinal bleeding was diagnosed by intraoperative enteroscopy.

CONCLUSION

A combination of inversion of Meckel's diverticulum with ectopic pancreatic tissue is extremely rare, particularly in elderly patient. Capsule endoscopy, double balloon enteroscopy, and ultimately intraoperative enteroscopy may be helpful in timely diagnosis.

A modified radiofrequency-assisted approach to right hemihepatectomy

AIMS

To evaluate a modified radiofrequency-assisted approach to right hemihepatectomy.

METHODS

Following a bilateral subcostal incision and intraoperative ultrasonography, the liver was mobilized in the standard manner, and a cholecystectomy was performed. The portal vein was isolated, encircled, and ligated. After demarcating the liver parenchyma, coagulation necrosis was achieved using a radiofrequency-assisted device along the line demarcated for transecting the liver parenchyma. The actual transection of the liver parenchyma and the right portal vein was done using a surgical scalpel along the radiofrequency-coagulated line. The right hepatic vein was coagulated using the radiofrequency sealer or by stitching in the resection plane. The hepatic artery was not dissected and was sealed together with the bile ducts in the resection plane using the radiofrequency instrument. The hepatic vein was not divided.

RESULTS

Between July 2005 and July 2006, a total of 49 liver resections were performed in our unit. Of these, the radiofrequency-assisted technique was used in 33 cases with metastatic disease; 14 of these cases had right hemihepatectomies, including 2 repeat resections. The mean operation time was 180min (range, 120-240min), and the average blood transfusion was 0.14U (range, 0-2U). Postoperatively, there was no morbidity, such as bleeding, infection, or biliary fistula, related to the liver resection technique, and no patients died as a result of surgery. In 8 out of the 14 right hemihepatectomies, a right-sided pleural effusion was observed; 3 of them required evacuation.

CONCLUSION

This paper describes a modified radiofrequency-assisted hemihepatectomy, which allows one to obtain control of the portal blood flow going into the resected part of liver. The modified approach appears to be simple and safe.

[Radiofrequency assisted liver resection in non-cirhotic liver. Initial clinical experience]

AIM OF THE STUDY

To evaluate the radiofrequency assisted liver resection using Habib sealer (RITA Medical System, Inc., Mountain View, CA).

METHODS

The operation time, liver transection time, transfusion units used, and postoperative complications were recorded in a prospective way.

RESULTS

22 liver resections were performed between July 2005 and December 2005, 15 of them were done using radiofrequency technique. Twelve anatomical resections and three non-anatomical resections were performed in total. The mean operation time equalled 155 (120-240) minutes. An average of 0.6 (0-4) transfusion units was used. In 13 of the 15 operations, which represent 86% of the patients, no transfusions were used. Postoperatively, no major bleeding from the resection plane was noted and no biliary fistula was observed.

CONCLUSIONS

Radiofrequncy assisted liver resection is a safe technique with the major benefit of minimal perioperative blood lost.

A rare cause of mediastinal expansion with a massive pleural effusion

The authors present a case of a 53 year old woman, who was admitted to hospital because of an unusual cause of massive pleural effusion. During diagnostic examination the mediastinal propagation of the pancreatic pseudocyst was discovered as a complication of the chronic calcifying pancreatitis. The patient was operated on and the pseudocyst was resolved by Roux-en-Y cystjejunostomy. The diagnostics and treatment of this unusual pancreatic pseudocyst spreading is discussed.

[Amoebic liver abscess--case report]

The authors present a case of a young male, who suffered with extraintestinal form of amoebiasis-amoebic liver abscesses. The patient traveled to India two month before symptoms onset. The diagnosis based on ultrasonography and computed tomography was definetely confirmed by serological examination. Metronidazol treatment was given initially, followed by percutaneous drainage. Open surgical tretment was indicated due to failure of percutaneous treatment. Patient was discharged home in a good condition one month after surgery. At this time patient is doing well eight months after surgery.

[Diagnosis of spontaneous arteriovenous fistula complicating aortoiliac aneurysm using spiral CT. Report of 3 cases]

Acute spontaneous arterio-venous fistula complicating atherosclerotic abdominal aortic aneurysm (AAA) is rare. This life-threatening setting is observed in 1-2% of all AAAs and 2-4% of ruptured of AAAs. The triad of abdominal or lower back pain, pulsatile abdominal mass, and continual abdominal machinery-like bruit is seen only in half of cases. Currently, CT angiography is a noninvasive technique which enables a rapid and exact preoperative diagnosis. The authors describe three cases of aortoiliac aneurysm complicated by an acute arteriovenous fistula which were diagnosed using spiral CT.

[Puncture gastrostomy in oncologic patients]

Puncture gastrostomies--percutaneous endoscopic gastrostomy and radiologically assisted gastrostomy--are minimally invasive methods to ensure an approach for the administration of enteral nutrition. These methods replaced the insertion of tubes during surgery (surgical gastrostomy). Percutaneous endoscopic gastrostomy (PEG) is inserted by means of a gastroscope, usually by the pull method, radiologically assisted gastrostomy (RAG) is implemented after insufflation of the stomach by a thin tube directly across the abdominal wall by the push method. In oncological patients it is preferable to administer enteral nutrition via puncture gastrostomy in case of obstruction of the upper portion of the digestive tract (oral cavity, larynx, pharynx, oesophagus), in deglutition disorders caused by cerebral tumours or in order to improve the nutritional status of patients with tumour cachexia. In the authors group in 1995-2000 a total of 53 puncture gastrostomies were made in 53 patients, 37 men and 16 women, mean age 62 years (32-94 years, incl. 38 PEG and 15 RAG. In 30 patients the reason was obstruction of the upper digestive tract, in 11 patients impaired swallowing associated with a cerebral tumour and in 12 patients the cause was tumourous cachexia. Puncture gastrostomies are well tolerated by the attending staff and patients, in oncology they can be used for administration of enteral nutrition under hospital and domiciary conditions.

[Recurrent adhesive ileus after surgical treatment of ovarian teratoma, malposition of an intrauterine device and dolichosigmoid--case report] ]

A 30-year-old woman was operated for ovarian teratoma and repeatedly for adhesive ileus during 1995-1999. A partial left ovarectomy, extirpation of an intrauterine device (IUD) in malposition (greater omentum) and appendectomy were performed during the first operation. Early adhesive ileus developed on the fourth postoperative day. Adhesectomy was performed in the region of the terminal jejunum. A new adhesive ileus developed after twenty seven months when patient underwent laparoscopy for gynaecological problems with conversion to laparotomy because of greater adhesions intraperitoneally another adhesectomy was performed. During the next eleven months new adhesive obstructions of the bowel developed and a third operation had to be performed incl. resection of the dolichosigmoideum on account of chronic problems during defaecation. A special tube as a intraluminal splint was inserted as prophylaxis of mechanical ileus in the postoperative period. But during next thirteen months subileous conditions and mechanical ileus developed again (up to now). The picture of intraperitoneal conditions was disastrous: almost total fibrotic changes allowed only partial adhesectomy. The passage through bowel is limited and is restricted to dietetic and medicamentous preparations. This case-report demonstrates postoperative adhesions a very old and very serious problem at the beginning of the third millennium.

[Immunologic follow-up of HIV-positive patients. C3, C4 complement components during HIV infection]

Investigations of the authors' patients with HIV infection revealed marked changes in the C3 and C4 components of complement. Of 61 investigated patients with HIV infection only 23 patients (37.7%) had values of the C3 component at the level recorded in controls. Values of the C4 component comparable with the control group were recorded in 24 patients (39.3%). From figures 1 and 2 it apparent that in the investigated group there is a striking hypercomplementaemia of both components, as compared with hypocomplementaemia.

[Immunologic study in HIV-positive patients. Hypergammaglobulinemia in HIV infection]

In all groups of patients--HIV, ARC, AIDS carriers--elevated serum concentration of IgG, IgA, IgM were found. In the group of HIV carriers a significant increase of the serum concentration of IgG at the 5% level was observed and of IgM at the 1% level. In patients with ARC a significant increase of IgG and IgA was found at the 5% level and of IgM at the 1% level. In patients with AIDS significantly raised IgG values at the 5% level were recorded, and of IgA and IgM at the 1% level. In IgA a permanent increase of values occurs in AIDS carriers. In the AIDS stage 86% of the patients have values higher than mean +/- SD of controls. In all three stages of HIV infection a rise of concentrations of circulating immunocomplexes was observed (p < 0.01). The highest levels were recorded in patients with AIDS. In none of the patients the presence of antinuclear antibodies was detected. The authors discuss also possible causes of hypergammaglobulinaemia in HIV infection.

[Immunologic monitoring of HIV-positive patients. T-lymphocytes and their subpopulations in various clinical stages of HIV infection]

The authors evaluate T-lymphocytes and their sub-populations, the immunoregulating index and white cell haemogram in patients in different clinical stages of HIV infection. They discuss the importance of the investigated parameters, in particular the number of CD4+ T-lymphocytes in the peripheral blood stream as a laboratory criterium for the development of the disease. From the paper ensues that evaluation of the number of CD4+ T-lymphocytes in the peripheral blood stream can help to estimate the time of the primary infection and the selection of an optimal time for starting azidothymidine therapy, but alone it does not suffice for establishment of the prognosis of the development of the HIV infection.

[The significance of endoscopic retrograde cholangiopancreatography in the diagnosis of pancreatic injuries in children]

The condition of the main pancreatic duct determines very probably in a decisive way the fate of posttraumatic pancreatic pseudocysts and acute pancreatic injuries. Endoscopic retrograde cholangiopancreatography is the only diagnostic method which makes possible to evaluate the condition of this duct. The authors performed ERCP in three children, in two of them an internal drainage of the pseudocyst was carried out on account of verified ductal rupture. In the third girl, after evidence of an intact main pancreatic duct, conservative therapy was successfully applied. In the discussion the authors summarize data from the literature regarding the use of ERCP in the preoperative diagnosis of posttraumatic pancreatic pseudocysts and acute pancreatic injuries. The authors consider ERCP a method which renders the diagnosis of posttraumatic pancreatic pseudocysts and acute pancreatic injuries more accurate.

[Submicroscopic structure of amniotic fluid cells]

Submicroscopic examination of amniotic fluid cells in the second trimester of pregnancy revealed that the cells are from the morphological aspect a very heterogeneous population, comprising vital and degenerated cells the ultrastructure of which rules out the possibility of cultivation of cells of foetal as well as of maternal origin. As to degenerated cells, the authors identified circular cells with a granular cytoplasm and nucleus originating from the urogenital or digestive tract of the foetus. Furthermore cells with a process and segmented or fragmented pycnotic nucleus derived from granulocytes and macrophages of maternal origin. Also circular cells of the periderm with short microvilli and advanced regressive changes of the nucleus and cytoplasm are degenerated. Among non-vital elements also anuclear completely keratinized cells of the stratum corneum originating from the skin of the maternal abdomen can be included. As to vital elements, the amniotic fluid contains cells of the amniotic ectoderm which are large, have numerous microvilli, a dense margin and a network of filaments in the cytoplasm. They are the most numerous cells. Other vital elements in amniotic fluid include granulocytes and macrophages with a typical ratio of lyzosomes. Both are considered elements of maternal origin. Maternal origin is assumed also in fibroblasts which along with collagen particles may penetrate into the aspirating needle. From the results ensues that the cells in amniotic fluid are not a homogeneous population of unequivocally foetal origin and that a better technique of collection of samples and cultivation must be developed.

[Morphologic changes in the heart atrium in frogs after extinction of current due to suction electrode induced damage]

In biological model experiments in frog heart morphological substrate was observed in current extinction due to damage under suction electrode. After short-term suction discharge monophase recording disappeared without demonstrable myocyte ultrastructure changes by means of reparation ad integrum. Monophase recording spontaneously disappeared in distinct changes of monocyte structure with enlarged spaces in between myofibrils, with breakdown of cristae in mitochondria and with dilatation of tubules and cisternae of the endoplasmic reticulum. This tissue disintegration leads to demarcation and forming of new cellular surfaces on the border with the healthy tissue so that the damaged area turns into a mere electric conductor.

Some immunological characteristics of subjects suffering from frequent herpes simplex virus recrudescences

Some parameters of specific and non-specific immunity were tested in a group of 44 subjects suffering from frequent herpes simplex type 1 (HSV-1) or herpes simplex type 2 (HSV-2) recrudescences. The tests performed included determinations of (i) HSV complement-independent and complement-dependent neutralizing antibodies, (ii) antibodies to glycoprotein C of HSV-1 and glycoprotein G of HSV-2, (iii) antibodies to viral capsid and early antigens of Epstein-Barr virus, (iv) antibodies to tetanus toxoid, (v) serum levels of IgM, IgG, IgA, transferrin, prealbumin and C'3 and C'4 components of complement, (vi) active and total T lymphocytes, (vii) phagocyting activity of polymorphonuclear neutrophils, eosinophils and mononuclear cells, (viii) skin reactivity to tuberculin, toxoplasmin, candidin, tetanus and diphtheria toxoids. In the patients the following deviations from the control groups were noted: (i) Antibody levels to homotypic but not to heterotypic HSV were enhanced, (ii) serum IgM levels were elevated, (iii) percentages and numbers of active and total T lymphocytes were decreased, (iv) phagocyting activity of neutrophils was depressed but that of eosinophils was increased.

[Treatment of pyogenic liver abscesses using percutaneous transparietal drainage]

Authors present their own experience with the method of external transparietal drainage of pyogenic hepatic abscesses. It is both effective and available method with minimum complications if performed in time. Mortality rate is much lower than in surgical drainage. Percutaneous drainage of hepatic abscesses depends on the possibility of their diagnostics by means of ultrasonography or computer tomography and access to special instruments.