European Resuscitation Council COVID-19 guidelines executive summary

Coronavirus disease 2019 (COVID-19) has had a substantial impact on the incidence of cardiac arrest and survival. The challenge is to find the correct balance between the risk to the rescuer when undertaking cardiopulmonary resuscitation (CPR) on a person with possible COVID-19 and the risk to that person if CPR is delayed. These guidelines focus specifically on patients with suspected or confirmed COVID-19. The guidelines include the delivery of basic and advanced life support in adults and children and recommendations for delivering training during the pandemic. Where uncertainty exists treatment should be informed by a dynamic risk assessment which may consider current COVID-19 prevalence, the person’s presentation (e.g. history of COVID-19 contact, COVID-19 symptoms), likelihood that treatment will be effective, availability of personal protective equipment (PPE) and personal risks for those providing treatment. These guidelines will be subject to evolving knowledge and experience of COVID-19. As countries are at different stages of the pandemic, there may some international variation in practice.

Immunological and biochemical markers in preeclampsia

A basic precondition for the development of preeclampsia is the presence of placental trophoblast cells in the maternal blood circulation. On the other hand, while trophoblast cells are present in the blood of all pregnant women, preeclampsia occurs in only 2-5% of them. Evidently, other factors play a crucial role. The aim of this study was to compare a set of selected immunological factors (anti-cardiolipin autoantibodies, trophoblast-induced cell-mediated immunity, C3 and C4 complement components) and biochemical factors (serum immunoglobulins IgA, IgG, IgM) among three groups of women with uncomplicated pregnancy, gestational hypertension, or preeclampsia. Blood samples were taken 2-12h before delivery. In the preeclampsia group, there was a significantly higher number of women positive for anti-cardiolipin autoantibodies, trophoblast-induced cell-mediated immunity was elevated, serum IgG was elevated and C4 complement component was reduced. We conclude that both elevated autoimmune reactivity and the higher immune reactivity to trophoblast may contribute to the onset of preeclampsia.

[New therapeutic approach of keratoconus with intracorneal ring segments aided by femtosecond laser (Tecnolas Perfect Vision): indications, operating technique and results]

OBJECTIVE

To assess the results of intracorneal ring segment implantation assisted by the Tecnolas Perfect Vision(®) femtosecond laser (Heidelberg, Germany).

SETTINGS

Retrospective observational study.

METHODS

The patients were operated on with the Tecnolas Perfect Vision(®) femtosecond laser. The following parameters were evaluated before and after surgery: uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), corneal topography, wavefront analysis, and central corneal thickness. The Wilcoxon test was used for statistical analysis.

RESULTS

Seventeen eyes of 15 patients were included. The mean follow-up was 6.9±0.71 months. Significant improvement of UCVA and BCVA was observed in 82.35% (P=0.027) and 94.12% (P=0.003) of the eyes, respectively. The subjective refraction showed a significant decrease of the sphere from -10.29±5.54 to -6.5±5.03D (P=0.002). The subjective cylinder significantly decreased from 5.43±3.20 to 3.69±2.30D (P=0.026). The SAI also decreased significantly (P=0.011).

CONCLUSION

Femtosecond-assisted intracorneal ring segment implantation is an effective treatment for corneal ectasia. Further studies are needed to improve surgical parameters and outcomes.

[Mechanisms influencing implantation of the embryo--the last-years' news]

OBJECTIVE

To summarize recent knowledge concerning mechanisms which influence the implantation of embryo.

DESIGN

Literature-based overview.

SETTING

Institute for the Care of Mother and Child, Prague. SUBJECT OF THE STUDY: Factors influencing implantation of embryo in the uterus elicit increased interest due to study of unexplained failures of embryotransfer following the successful in vitro fertilization. Our article points to recent information about physiology and pathology of mechanisms controlling implantation, namely the factors of immunity (antibodies, cells, cytokines and other mediators) whose exact regulation on the feto-maternal interface is a crucial precondition of successful implantation. Also the genetics of early embryo, as well as the possibilities of modern endoscopic techniques offer new insight onto mechanisms of implantation. Recommendations for diagnostics and treatment of implantation failure are given in the end of the article.

[Immunologically conditioned fertility disorders in men--experience of the immunobiological department of the Institute for Maternal and Child Care]

OBJECTIVE

To provide an overview of the results obtained from the more than ten-year systematic monitoring of the contribution of immunopathological mechanisms to the ethiopathogenesis of fertility disorders in men.

DESIGN

A summarising retrospective study.

SETTING

Mother and Child Care Institute, Prague.

METHODS

The data source is a selected group of a total of 3,800 couples, who were examined in the Immunobiological Department (ID) of the Mother and Child Care Institute (MCCI) in Prague- -Podolí for fertility disorders in the past. From among the laboratory quantities, the following ones were systematically monitored: a) sperm parameters; b) cell-mediated immunity against spermatozoa; c) the presence of anti-spermatozoa auto-antibodies attached to spermatozoa; d) in a part of the clinical group, the serum concentrations of FSH, testosterone, SHBG and the free androgen index (FAI) were monitored.

RESULTS

After selection was made according to defined criteria, the group comprised of a total of 1,680 men, of whom 49.4% were normozoospermic and 50.6% suffered from some form of seminal pathology. Increased cell-mediated immunity against spermatozoa was identified in 10.2% of fertile men, in 18.5% of normozoospermic men and in 66.3% of azoospermic men. In asthenozoospermic and teratozoospermic men, the increased cell-mediated immunity against spermatozoa was identified in 48.3% and 53.1% of them, respectively. The auto-antibodies attached to spermatozoa were identified in 3 out of every 42 fertile men (7%), while in asthenozoospermic men, it was a total of 21% (IgA antibodies) and 22% (IgG antibodies). As concerns the concentration of free androgens (FAI) in the serum, there was no difference among the individual subgroups of men. In oligoasthenozoospermic men, FSH was significantly higher on the average in comparison with normospermic men.

CONCLUSION

The significantly higher incidence of increased cell-mediated immunity against spermatozoa in men with a pathological spermiogram in comparison with the control group (fertile men and normozoospermic men) indicates that cell-mediated immunity participates in the pathogenesis of seminal pathologies.

[Immunopathological and histopathological aspects of ectopic implantation with possible effect on fertility disorders]

OBJECTIVE

To evaluate leucocytic infiltration of fetomaternal interface in ectopic pregnancy and to evaluate the changes in cell immunity against trophoblast (AT-CMI) in women with extrauterine pregnancy (GEU) in their medical history. To assess the effect of these factors on possible fertility disorders in a woman.

DESIGN

A retrospective study.

SETTING

Mother and Child Care Institute, Prague.

METHODS

In most of the patients, we addressed GEU through laparoscopy. The tube was extirpated in toto and immediately fixed in Baker's solution. Thereafter, it was prepared in a dissection microscope and then processed in a standard way. In order to identify the intensity of AT-CMI, we used the leucocyte migration inhibition test. The cytotrophoblastic cell line JAR was used as an antigen. The degree of inhibition of the migration was monitored by means of a computer image analyser. Inhibition of migration below 75% was rated as favourable.

RESULTS

We monitored the presence of inflammatory infiltrate in the place of implantation and correlated the findings with the hCG levels and the presence of the foetal ovum or its part in the tube. In 28 patients (23.5%) of the total number of 119 patients in the group, we observed an inflammatory infiltrate in the place of implantation. In these patients, the hCG levels were lower and in 17 of them (60.7%) we did not prove the presence of a foetal ovum or its parts. In women with GEU in their medical history, the AT-CMI positivity was established in 61.1% of the women 1 year after surgery, in 56.8% of the women 1-3 years after surgery and in 41.2% of the women 3 years after surgery.

CONCLUSION

Ectopic pregnancy involves a pathological fetomaternal interface. The leucocytic infiltrate in the area of implantation may be of secondary character and may cause gradual destruction of the ectopically positioned product of conception. The results of our study indicate a possible participation of the increased AT-CMI in the destruction of the ectopically located trophoblast. Persisting anti-trophoblast immunity may influence the occurrence and course of further gravidities.

Markers of inflammation in preeclampsia

Advanced oxidation protein products (AOPP) represent terminal products of proteins exposure to free radicals. The aim of this study was to estimate the serum AOPP levels in preeclamptic patients together with ultrasensitive C-reactive protein and anticardiolipin antibodies (ACA) IgG and IgM. 21 women in the third trimester of pregnancy were included in the study--10 women with preeclampsia and 11 women with normal outcome of pregnancy. AOPP levels in preeclampsia were higher than those in normal pregnant women in the third trimester, but not statistically significantly. The comparison with AOPP levels in non-pregnant women has shown a significant increase (P<0.0001). CRP in preeclampsia was significantly increased in comparison with third trimester levels in normal pregnancy (P<0.001) as well as with non-pregnant women (P<0.0001). In preeclampsia, the ACA IgG levels were even significantly lower than in normal pregnant women in the same gestation age, but significantly higher than in non-pregnant women (P<0.001). No difference was found in ACA IgM in preeclampsia and normal third trimester pregnancy and non-pregnant women. A statistically significant negative correlation was found between AOPP and ACA IgG (r= - 0.708, P<0.05). The results indicate enhanced oxidative and inflammatory reaction of maternal organism to pregnancy, which is more pronounced in preeclampsia than in uncomplicated pregnancy.

[Role of sperm antibodies and cellular autoimmunity to sperm in the pathogenesis of male infertility]

OBJECTIVE

To test the hypothesis of relationship between sperm pathology and elevated humoral and/or cell-mediated antisperm autoimmunity in male partners from infertile couples.

DESIGN

Analytic study.

SETTING

Department of Immunobiology, Institute for the Care of Mother and Child, Prague.

METHODS

Sperm samples were evaluated according to WHO rules. Sperm-bound antisperm autoantibodies (ASA) were determined by SpermMar Test (FertiPro N. V., Sint-Martens-Latem, Belgium). For evaluation of cell-mediated antisperm autoimmunity (CMAA) the authors used their own modification of migration-inhibition test (Dimitrov et al., J. Immunol. Methods 154: 147, 1992).

RESULTS

The pool of men was divided into groups according to the result of sperm examination: normozoospermia (740 men), asthenozoospermia (244), teratozoospermia (191), oligoasthenozoospermia levis (61), oligoasthenozoospermia gravis (29), oligoteratozoospermia (82), and azoospermia (54). Subgroup of fertile men (32) consisted of normozoospermic men--fathers of child younger than 3 years. Percentage of sperm-bound ASA-positive samples was significantly higher in asthenozoospermia in comparison with normozoospermia in both IgA (20.8% versus 10.6%) and IgG classes (13.8% vs 6.8%). Positivity of CMAA was significantly more frequent in group of asthenozoospermic (52%) than in normozoospermic (28.5%) and fertile (12.5%) men.

CONCLUSION

Antisperm autoimmunity, namely its cell-mediated form, appears to play a significant role in impairment of spermiogenesis. Sperm-bound autoantibodies were found more frequently in asthenozoospermia, but also in some men with normozoospermia they may impair fertility.

Autoimmune antiovarian antibodies and their impact on the success of an IVF/ET program

In previous papers, we referred to studies of the influence of antiovarian autoantibodies on menstrual cycle disorders in adolescent girls. We examined autoantibodies against ooplasma, zona pellucida, membrana granulosa, theca folliculi interna, and lutein cells. In infertile women in the IVF/ET program, we studied the positivity of antiovarian antibodies and cytokines, namely, TNF-alpha and IL-1 beta, in follicular fluid correlated with the following subgroups, characterized by the outcome of in vitro fertilization, as follows: G, pregnant; F, fertilized; N, nonfertilized; and O, no oocyte gained. The presence of autoantibodies corresponds to the success or failure of the IVF/ET program. Our results support the hypothesis that antiovarian autoantibodies play an important role in both the endocrine and the reproductive function of the human ovary and that it can influence them negatively.

[Use of human sperm protein monoclonal antibodies in the diagnosis of sperm pathology and selection of a suitable assisted reproduction method for fertilization]

OBJECTIVE

Use of monoclonal antibodies against sperm proteins in human medicine.

DESIGN

Experimental and clinical studies.

SETTING

Dep. Biology and Biochemistry of Fertilization, Institute of Molecular Genetics, Prague, Laboratory IVF, Iscare IVF, Prague, Dep. of Immunobiology, Institute for the Care of Mother and Child, Prague.

METHODS

Monoclonal antibodies against human sperm intra-acrosomal and cell surface proteins were used for quantitative analysis of these proteins by the immunofluorescence test in samples of human sperm of good and poor qualities.

RESULTS

The detection of intra-acrosomal proteins was decreased and, on the other hand, detection of surface proteins was the same or higher in pathological spermatozoa.

CONCLUSIONS

Monoclonal antibodies can be used for diagnostics of sperm pathology (quantitative detection of proteins) and for evaluation of the physiological state of sperm cells (state of acrosome before or after acrosome reaction). Finally, monoclonal antibodies could be useful for selection of a suitable method of fertilization (IUI, standard IVF, ICSI) in the laboratories of assisted reproduction.

Surfactant-deficient respiratory distress after elective delivery at 'term'

Babies of 37-41 wk gestation are, by international convention, said to be born at 'term', but some still develop respiratory distress. It is not clear how mature a baby has to be to be free of risk of primary surfactant deficiency. An area-based retrospective study of all the 179,701 babies of 34 or more weeks' gestation born alive in a defined area of the north of England in 1988-92 identified 149 babies with features of respiratory distress typical of surfactant deficiency severe enough to be managed with ventilatory support and with no evidence of aspiration or intrapartum infection. Gestation was carefully cross-validated against antenatal information, including at least one ultrasound assessment in the first half of pregnancy. Thirty-six of these babies were born at or after 37 wk gestation. Only 4 of the 35 delivered at 37-38 wk went into spontaneous labour. Seven became ill enough to be candidates for ECMO and two died. A review of all neonatal deaths in the study area between 1981 and 1995 identified four similar deaths in 1981-87 and two in 1993-95. Babies who are not premature, using the internationally agreed definition, can show signs of potentially lethal pulmonary immaturity at birth, especially if subjected to pre-labour Caesarean delivery. Those born at 37-38 wk are 120 times more likely to receive ventilatory support for surfactant deficiency than those born at 39-41 wk. Elective delivery should only be undertaken before 39 wk gestation for good medical reasons.

[Practical results of monitoring pregnancy in women with systemic lupus erythematosus]

BACKGROUND

The authors dealt with the urgent problem under what conditions it is possible to achieve in a woman with systemic lupus erythematosus (SLE) or another collagenosis, or secondary antiphospholipid syndrome (APS) a favourable outcome of pregnancy and the delivery of a healthy infant.

METHODS AND RESULTS

The investigation comprised 23 women incl. 20 with SLE, two with the mixed form of a diffuse connective tissue disease (MCTD) and one with Sjögren's syndrome of the primary type. From the total number of 20 pregnancies six were consulted in advance with a doctor (group I-s-called planned pregnancies) and all terminated by a successful delivery. Of 11 pregnancies which were not consulted with a doctor in advance (group II-so-called unplanned pregnancies) 9 were terminated in term, however, only 5 with a successful delivery (55.5%), two women are still pregnant. Exacerbation of the basic disease during pregnancy was recorded only once and did not lead to discontinuation of the pregnancy.

CONCLUSIONS

The authors provide evidence that desired pregnancy of informed women suffering from SLE or another collagenosis when assisted by a specialized medical team can lead to a successful delivery of an infant.

Correlation of asthenozoospermia with increased antisperm cell-mediated immunity in men from infertile couples

To investigate whether cell-mediated immunity (CMI) against sperm and/or antisperm circulating antibodies are associated with poor semen quality, a leukocyte migration inhibition factor (LMIF) assay and an enzyme-linked immunosorbent assay (ELISA) were performed in groups of men from infertile couples, men from fertile couples and sperm donors. Twenty-five of 102 men (25%) revealed positive CMI against sperm and 10 (10%) had positive antisperm antibody titers in their sera. Fifteen of 28 asthenozoospermic men (53%) from infertile couples revealed positive antisperm CMI. The incidence of antisperm CMI was significantly increased (P < 0.05) in the infertile men with asthenozoospermia compared with the men from the other two groups (men from fertile couples and sperm donors). No significant differences between migration indices were seen when such a comparison was done for oligoasthenoterato- and teratozoospermics. The results indicate that increased antisperm CMI is associated with asthenozoospermia in a significant number of men from infertile couples. The importance of these findings is discussed.

Immunological properties of heterozygous nu/+ mice: changes in antibody response and inducibility of tolerance to protein antigens

Heterozygous nu/+ mice are not fully identical in their immunological properties with the mice of wild +/+ genotype. A colony of nu/nu, nu/+ and +/+ mice from the same breeding nucleus was established and their immune reactivity to human serum albumin, inducibility of adult immune tolerance to hen egg lysozyme (HEL), sensitivity of their lymphoid cells to stimulation by mitogens and ratio of CD3, CD4 and CD8 positive cell populations was studied. Both the numbers of antibody-forming cells in regional lymph nodes and the antibody titres in sera of nu/+ mice were highly variable, between undetectable values of nu/nu and high values of +/+ homozygotes. Intravenous pretreatment with soluble HEL, leading in +/+ mice to a deep hyporeactivity to subsequent immunization with the same antigen, did not decrease the response of nu/+ mice significantly. These results indicate that the immunological alteration of nu/+ mice is not only quantitative and that T cell subpopulations might be differentially modified by the presence of nu allele. The finding of decreased CD4:CD8 ratio in nu/+ mice also supports this idea.

IL-2 influences the balance between immunity and unresponsiveness in the picryl (TNP) contact sensitivity system by blocking the development or action of an Lyt-2+, I-J+ T suppressor cell

Mice injected with antigen (picrylated spleen cells) intravenously fail to develop contact sensitivity. However, contact sensitivity occurs if these mice are injected with IL-2. This effect of IL-2 was reproduced in vitro by taking spleen cells 2 days after injecting antigen intravenously and culturing them with either 150 u/ml recombinant IL-2 for 2 days or by pulsing with 600-1200 u/ml IL-2 at 4 degrees C for 1 hr. After 2 days in culture these antigen-exposed cells transfer contact sensitivity to naive recipients in a 24-hr experiment. However, the ability of antigen-exposed cells, pulsed with IL-2, to transfer contact sensitivity is abolished when they are incubated with unpulsed antigen-exposed cells and as few as 1/16 of their number have a significant effect. This phenomenon is specific, as normal cell or cells from mice injected with oxazolonated cells intravenously have no effect. The suppressor cells were Thy-1+, Lyt-1-, 2+, I-J+ T cells. It was concluded that IL-2 prevents the development/action of antigen-specific T suppressor cells.

Generation of lymphokine-activated killer cells does not require DNA synthesis

We studied the role of DNA synthesis in the induction of lymphokine-activated killer (LAK) cells by recombinant interleukin-2 (IL-2) and the dependence of this phenomenon on DNA synthesis. Doses of gamma-irradiation (1000-5000 rads) that profoundly reduced DNA synthesis in human peripheral blood mononuclear leucocytes (PBL) also effectively suppressed the development of cytotoxic activity in the absence of IL-2. However, the same doses of irradiation affected the induction of LAK activity by IL-2 to a much lesser extent. Blocking the formation of deoxyribonucleotides by hydroxyurea, which resulted in a complete inhibition of DNA synthesis in PBL or purified T lymphocytes, had virtually no effect on the generation of LAK cells. These results indicate that the expression of LAK activity is not dependent on DNA synthesis.

Specific unresponsiveness to sheep red blood cells visualized by levamisole in athymic nude mice

The administration of levamisole at the time of and 2 days after challenge with 10(8) SRBC significantly increased the direct anti-SRBC PFC response of nude mice. Pretreatment of nude mice of BALB/c and C 57 B1/10Sn strains with 10(9) or 10(8) SRBC injected 14 and 7 days before challenge suppressed the increase of the immune response. Pretreatment with 10(7) SRBC did not induce this inhibition. Administration of levamisole at the time of pretreatment with SRBC did not prevent the induction of inhibition. It is suggested that B cell exhaustion is the cause of the observed unresponsiveness.

Immunological unresponsiveness to HSA in chickens

HSA injected into chickens after hatching induces suppression of anti-HSA antibody formation. Unresponsive chickens react by producing the anti-HSA antibodies earlier and more intensively after BSA challenge than after challenge with HSA. This effect cannot be ascribed to T cells, because they were found to play no substantial role in the unresponsiveness to HSA. Neither was active suppression, which could account for the depressed antibody production, detected. B cell inactivation seems to be the major mechanism involved in this unresponsiveness. However, some additional mechanism must prevent B cells of unresponsive chickens from producing anti-HSA antibodies after HSA challenge, although they are able to form them after immunization with BSA. We suggest that cellular interactions, either between B cells of different specificities or between B cells and macrophages, are responsible for this differential reactivity.

Inhibitory effects of 5-azapyrimidine nucleosides on cellular immunity

The effect of 5-azacytidine (5-AzCR) and 5-aza-deoxycytidine (5-AzCdR) on the survival of skin grafts in mice and rats, the action of these drugs on regional GVH reaction, as well as the formation of haemopoietic colonies (CFU-5) in the spleen were studied. Both drugs prolonged the life span of skin grafts when administered 24 hr before transplantation, or on the 4th post-transplantation day. However, they were little effective when injected 24 hr after skin grafting, or after induction of the regional GVHR. Following intraperitoneal administration, they inhibited CFU-5 formation. Two-hour incubation in vitro of cells with 5-AzCR significantly reduced their GVH reactivity and capacity to form CFU-5; 5-AzCdR under the same conditions was ineffective.

Effect of 5-aza-2'-deoxycytidine on antibody formation and DNA synthesis in rat spleen

5-Aza-2'-deoxycytidine which is preferentially taken up by the lymphatic tissue and is incorporated into DNA strongly affects the ability of the immune system to synthesize IgG antibodies against sheep red blood cells without affecting IgM antibody formation. A single dose of the drug results in a prolonged inhibition persisting 14 days after the secondary immunization. The inhibitory effect is dose-dependent and is maximal when 5-aza-2'-deoxycytidine is given 2 days after sheep erythrocytes. The drug affects the utilization of thymidine for the synthesis of DNA in the spleen; under certain conditions the enhancement of the rate of DNA synthesis in the spleen has been observed.

Insulin effect upon the "in vitro" glucose uptake by the white rat thymus during the age - and hydrocortisone - induced thymus involution

Insulin at a physiological concentration (10(-3) IU/ml incubation medium) did not modify the glucose uptake by the thymuses of young rats, but increased significantly the glucose uptake by the involuted thymuses of older animals. Insulin at the same concentration enhanced the glucose uptake of the thymuses which underwent an accidental hydrocortisone-induced involution. Parallely, the effect of insulin on insulin dependent peripheral tissues (diaphragm and epididymal fat pad) was followed. In the presence of cystine (4.13 mumole/ml) in the incubation medium increased the glucose consumption by the thymus of young rats. This fact is discussed on the basis of the -S-S bond-protecting effect of cystine against the distroying effect of free -SH groups released from the thymus into the incubation medium.

Age-dependent rapid antiinsulin effect of hydrocortisone hemisuccinate during insulin induced hypoglycemia in white rat

The effect of hydrocortisone hemisuccinate upon the intravenous insulin-induced hypoglycemia in various age-groups of white rats was studied. Insulin was injected intravenously in a dose of 10-(2) units per 100 g b.w. in the same age-groups of animals in a basal state, and 2 days later, 15 minutes after the i.p. administration of hydrocortisone hemisuccinate (0.5 mg/100 g b.w.). It has been estabished, that hydrocortisone hemisuccinate had a rapid anti-insulin effect, which is quantitatively different in dependence on the age of animals.