Intimate partner violence during pregnancy - Prevalence and associations with women's health: A cross-sectional study

OBJECTIVE

Intimate partner violence (IPV) against women occurs in all settings. Exposure to intimate partner violence, especially during pregnancy, is associated with serious adverse health outcomes and is recognized as a global health issue.

AIM

To describe the prevalence of physical, psychological, and sexual intimate partner violence among pregnant women in Sweden during current pregnancy, and to investigate potential associations between exposure and sociodemographic characteristics and health.

METHODS

Between October and December 2020, a cross-sectional survey study was conducted at 35 midwifery clinics in Stockholm, Sweden.

RESULTS

The questionnaire was answered by 3399 pregnant women. The results showed that 2.1% of the women reported exposure to intimate partner violence during pregnancy, with exposure to psychological violence being most common (1.8%), followed by exposure to physical violence (0.6%) and sexual violence (0.1%). Exposure to intimate partner violence was significantly associated with living situation and depressive symptoms, as well as education, country of birth, and employment status.

CONCLUSION

Exposure to intimate partner violence occurs even during pregnancy and it is crucial to identify pregnant women exposed to intimate partner violence in order to inform clinical practice and to provide adequate support. More research is needed to develop screening instruments to detect violence against pregnant women.

Once and Again: Intergenerational Transmission of Parenting

Introduction

Animal and human studies suggest that individual differences in maternal parenting behaviour are transmitted from one generation to the next.

Objective

This study aimed to examine potential psychosocial mechanisms underlying an intergenerational transmission of conceptualization of parenting, including affect, cognition, and parental support.

Methods

In a subsample of 201 first-time mothers participating in the Maternal Adversity, Vulnerability and Neurodevelopment (MAVAN) project, we assessed maternal childhood rearing experiences, using the Parental Bonding Instrument and the Childhood Trauma Questionnaire. At 6 months postpartum, mothers completed questionnaires on parenting stress, symptoms of depression, internalization of maternal care regulation and current relationship with mother and father.

Results

We found significant direct associations of maltreatment and rearing by the grandmother with parenting stress at 6 months. These associations were mediated through distinct psychosocial pathways: the association of maltreatment on higher parenting stress was fully mediated through more maternal symptoms of depression (z = 2.297; P = 022). The association between sub-optimal rearing provided by the mother and higher parenting stress was mediated through lower internalization of maternal care regulation (z = -2.155; P = 031) and to a lesser degree through more symptoms of depression (z = -1.842; P = 065). Finally, higher quality rearing by the grandfather was indirectly related to lower parenting stress through positive current relationship with the father (z = -2.617; P = 009).

Conclusions

There are distinct pathways by which early experiences manifest in parenting stress. By understanding the structure of dysregulated parenting, clinicians will have practical information to specifically target maternal motivation, social supports, and depressed mood to disrupt maladaptive parenting cognitions and practices.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

High-fat Diet and Physical Exercise Differentially Modulate Adult Neurogenesis in the Mouse Hypothalamus

The hypothalamus has emerged as a novel neurogenic niche in the adult brain during the past decade. However, little is known about its regulation and the role hypothalamic neurogenesis might play in body weight and appetite control. High-fat diet (HFD) has been demonstrated to induce an inflammatory response and to alter neurogenesis in the hypothalamus and functional outcome measures, e.g. body weight. Such modulation poses similarities to what is known from adult hippocampal neurogenesis, which is highly responsive to lifestyle factors, such as nutrition or physical exercise. With the rising question of a principle of neurogenic stimulation by lifestyle in the adult brain as a physiological regulatory mechanism of central and peripheral functions, exercise is interventionally applied in obesity and metabolic syndrome conditions, promoting weight loss and improving glucose tolerance and insulin sensitivity. To investigate the potential pro-neurogenic cellular processes underlying such beneficial peripheral outcomes, we exposed adult female mice to HFD together with physical exercise and evaluated neurogenesis and inflammatory markers in the arcuate nucleus (ArcN) of the hypothalamus. We found that HFD increased neurogenesis, whereas physical exercise stimulated cell proliferation. HFD also increased the amount of microglia, which was counteracted by physical exercise. Physiologically, exercise increased food and fat intake but reduced HFD-induced body weight gain. These findings support the hypothesis that hypothalamic neurogenesis may represent a counter-regulatory mechanism in response to environmental or physiological insults to maintain energy balance.

Diet-dependent alterations of hepatic Scd1 expression are accompanied by differences in promoter methylation

Obesity and alterations of lipid homeostasis are hallmarks of the metabolic syndrome and largely influenced by the dietary conditions of the individual. Although heritability is considered to be a major risk factor, the almost 40 candidate genes identified by genome-wide association studies (GWAS) so far account for only 5-10% of the observed variance in BMI in human subjects. Alternatively, diet-induced changes of epigenetic gene regulation might be involved in disturbed lipid homeostasis and weight development. The aim of this study was to investigate how a high-carbohydrate diet (HCD; 70 kcal% from carbohydrates, 10 kcal% from fat) or a high-fat diet (HFD; 20 kcal% from carbohydrates, 60 kcal% from fat) affects hepatic expression of genes involved in fatty acid metabolism and if these alterations are correlated to changes in promoter methylation. Expression of stearoyl-CoA desaturase 1 (Scd1) was lower in livers from HFD-fed C57BL/6 J mice compared to HCD-fed animals and correlated inversely with the degree of DNA methylation at 2 distinct, adjacent CpG sites in the Scd1 promoter. In contrast, expression of transcription factors peroxisome proliferator activated receptor alpha and gamma (Ppara, Pparg), and sterol regulatory element binding transcription factor 1 (Srebf1) was not affected. The degree of hepatic Scd1 promoter methylation at these CpG sites correlated positively to fat mass and serum leptin levels, whereas serum ghrelin levels were inversely correlated with methylation at both CpG sites. Taken together, hepatic expression of Scd1 is differentially affected by carbohydrate- and lipid content of the diet. These differences in Scd1 expression are associated with altered promoter methylation, indicating that diets affect lipid metabolism in the liver via epigenetic mechanisms.

Genetic variation in oxytocin rs2740210 and early adversity associated with postpartum depression and breastfeeding duration

Mothers vary in duration of breastfeeding. These individual differences are related to a variety of demographic and individual maternal factors including maternal hormones, mood and early experiences. However, little is known about the role of genetic factors. We studied single-nucleotide polymorphisms (SNPs) in the OXT peptide gene (rs2740210; rs4813627) and the OXT receptor gene (OXTR rs237885) in two samples of mothers from the Maternal adversity, Vulnerability and Neurodevelopment study (MAVAN), a multicenter (Hamilton and Montreal, Canada) study following mothers and their children from pregnancy until 7 years of age. Data from the Hamilton site was the primary sample (n = 201) and data from Montreal was the replication sample (n = 151). Breastfeeding duration, maternal mood (measured by the CES-D scale) and early life adversity (measured by the CTQ scale) were established during 12 months postpartum. In our primary sample, polymorphisms in OXT rs2740210, but not the other SNPs, interacted with early life adversity to predict variation in breastfeeding duration (overall F8,125  = 2.361, P = 0.021; interaction effect b = -8.12, t = -2.3, P = 0.023) and depression (overall F8,118  = 5.751, P ≤ 0.001; interaction effect b = 6.06, t = 3.13, P = 0.002). A moderated mediation model showed that higher levels of depression mediated the inverse relation of high levels of early life adversity to breastfeeding duration, but only in women possessing the CC genotype [effect a' = -3.3401, 95% confidence interval (CI) = -7.9466 to -0.0015] of the OXT SNP and not in women with the AA/AC genotype (a' = -1.2942, ns). The latter findings (moderated mediation model) were replicated in our Montreal sample (a' = -0.277, 95% CI = -0.7987 to -0.0348 for CC; a' = -0.1820, ns for AA/AC).

Stimulation of the titre of a sheep serum factor that is related to the sheep complement system

Serum from most sheep subjected to a single jugular bleeding, repeated bleeding or an intraperitoneal injection of yeast and repeated bleeding, showed an increase in the titre of a serum component called serum factor. Serum factor reached a peak titre 2 to 5 days after treatment started. For some sheep, the titre was elevated for a 9- to 12-day period whereas for others the titre dropped markedly on day 7 followed by a rise on day 9. Serum factor reacts with sheep erythrocytes sensitised with rabbit antibody (sheep E-rabbit A). Serum factor can be detected on sheep E-rabbit A using guinea-pig antiserum that reacts with sheep complement (C). Serum factor is inactivated by heating at 56 degrees C for 30 minutes, but is only partially inactivated at 50 degrees C for 30 minutes. The reaction of serum factor with sheep E-rabbit A is inhibited by chelators of Ca++ and/or Mg++. Serum factor appears to be related to the sheep C system. Preliminary results suggest it may he a component of the classical pathway of sheep C, possibly the second component, C2.

Effects of intrapartum oxytocin administration and epidural analgesia on the concentration of plasma oxytocin and prolactin, in response to suckling during the second day postpartum

BACKGROUND

Oxytocin and prolactin stimulate milk ejection and milk production during breastfeeding. The aim of the present study was to make a detailed analysis of maternal release of oxytocin and prolactin in response to breastfeeding during the second day postpartum in mothers who had received oxytocin either intravenously for stimulation of labor or intramuscularly for prevention of postpartum hemorrhage and/or epidural analgesia or those who had received no such treatment in connection with birth.

METHODS

In a descriptive comparative study plasma oxytocin and prolactin concentrations were measured in response to suckling during the second day postpartum in women who had received intravenous intrapartum oxytocin (n = 8), intramuscular postpartum oxytocin (n = 13), or epidural analgesia, either with (n = 14) or without (n = 6) intrapartum oxytocin infusion, and women who received none of these interventions (n = 20). Hormone levels were analyzed by enzyme immunoassay.

RESULTS

All mothers showed a pulsatile oxytocin pattern during the first 10 minutes of breastfeeding. Women who had received epidural analgesia with oxytocin infusion had the lowest endogenous median oxytocin levels. The more oxytocin infusion the mothers had received during labor, the lower their endogenous oxytocin levels were during a breastfeeding during the second day postpartum. A significant rise of prolactin was observed after 20 minutes in all women, but after 10 minutes in mothers having received oxytocin infusion during labor. In all women, oxytocin variability and the rise of prolactin levels between 0 and 20 minutes correlated significantly with median oxytocin and prolactin levels.

CONCLUSION

Oxytocin, released in a pulsatile way, and prolactin were released by breastfeeding during the second day postpartum. Oxytocin infusion decreased endogenous oxytocin levels dose-dependently. Furthermore, oxytocin infusion facilitated the release of prolactin. Epidural analgesia in combination with oxytocin infusion influenced endogenous oxytocin levels negatively.

Short- and long-term decrease of blood pressure in women during breastfeeding

BACKGROUND AND AIMS

The benefits of breastfeeding for infants are well known. Recently data have started to emerge showing that breastfeeding may also induce positive effects in the mother. This study aimed to investigate the pattern of maternal blood pressure before, during, and after a breastfeed 2 days postpartum. Additionally, blood pressure during the following 25-week breastfeeding period was investigated.

METHODS

Sixty-six primiparae with normal deliveries were consecutively recruited. Blood pressure was measured at -5, 10, 30, and 60 minutes in connection with a morning breastfeed. Thirty-three women continued to measure blood pressure before and after breastfeeding for 25 weeks.

RESULTS

Blood pressure fell significantly in response to breastfeeding 2 days after birth. The fall in systolic and diastolic blood pressure amounted to 8.8 (SD = 11.00) and 7.7 (SD = 9.3) mm Hg, respectively. During the 25-week follow-up period a significant fall of basal blood pressure (systolic, df = 3, F = 7.843, p < 0.001; diastolic, df = 3, F = 5.453, p = 0.002) was observed. The total fall in systolic and diastolic blood pressure amounted to a mean of 15 (SD = 10.4) mm Hg and 10 (SD = 9.7) mm Hg, respectively. In addition, blood pressure fell significantly in response to individual breastfeeding sessions during the entire observation period.

CONCLUSIONS

In conclusion, both systolic and diastolic blood pressures fall during a breastfeeding session, and pre-breastfeeding blood pressure decreases during at least the first 6 months of a breastfeeding period in a homelike environment. This study lends further support to the health-promoting effects of breastfeeding.

Newborn skin temperature two days postpartum during breastfeeding related to different labour ward practices

AIM

To investigate (1) the skin temperature pattern in newborns two days after birth in connection to breastfeeding and to examine (2) if the administration of epidural analgesia (EDA) and oxytocin (OT) infusion during labour influences this parameter at this point of time.

METHOD

Forty-seven mother-infant pairs were included in the study: nine mothers had received OT stimulation during labour (OT group), 20 mothers had received an EDA and OT during labour (EDA group), while 18 mothers had received neither EDA nor OT stimulation during labour (control group). A skin temperature electrode was attached between the newborn's shoulder blades. The newborn was placed skin-to-skin on the mother's chest and covered with a blanket. The temperature was recorded immediately after the newborn was put on the mother's chest and at 5, 10, 20 and 30 min.

RESULTS

The temperature measured when the newborns were put skin-to-skin on their mothers' chest was significantly higher in the infants of the EDA group (35.07 degrees C) when compared to the control group (34.19 degrees C, p=0.025). Skin temperature increased significantly (p=0.001) during the entire experimental period in the infants belonging to the control group. The same response was observed in infants whose mothers received OT intravenously during labour (p=0.008). No such rise was observed in infants whose mothers were given an EDA during labour.

CONCLUSION

The results show that the skin temperature in newborns rises when newborns are put skin-to-skin to breastfeed two days postpartum. This effect on temperature may be hampered by medical interventions during labour such as EDA.

Neuroprotection from glutamate toxicity with ultra-low dose glutamate

The protective effects of ultra-low doses (ULD) of glutamate against glutamate toxicity was studied in primary rat spinal, cortical and cerebellar neurons. Neurons were exposed to four subtoxic, ultra-low concentrations of glutamate (10(-18) M, 10(-20)M, 10(-22) M and 10(-30) M) for 72 h and then subsequently challenged with toxic concentrations (25 microM) of glutamate. Neuron viability was consistently 10% higher in spinal and cortical neurons pre-exposed to glutamate concentrations of 10(-18) M and 10(-22) M, and in cerebellar neurons pre-exposed to 10(-20) M and 10(-30) M. Using laser scanning confocal microscopy and the fluorescent calcium probe fluo-3, we found no alterations in intracellular calcium dynamics in the protected cells. This protective effect is consistent with a growing body of evidence for tolerance induced by low-dose toxin exposure but is the first time that such tolerance has been demonstrated with ultra-low glutamate exposure. Our data show that pre-exposure of neuronal cells to ULD glutamate can protect against subsequent exposure to toxic levels of glutamate.

Issues in the use of complementary/alternative medical therapies for low back pain

Unfortunately, current conventional medical treatments for low back pain are not managing the problem effectively. Standard approaches to treatment, particularly surgery, may even be exacerbating the problem and causing additional pain and suffering. In this context, it is understandable that LBP patients often go outside of the conventional medical system seeking other treatment options. Conventional medical physicians who treat low back pain patients, therefore, need to become more aware of the fact that their patients may be using complementary/alternative medical therapies.

Alternative medicine instruction in medical schools and family practice residency programs

BACKGROUND AND OBJECTIVES

The use of medical therapies outside of mainstream Western medicine, referred to as complementary medicine or alternative medicine (CAM), is rapidly increasing in the United States. Despite evidence of physician interest and willingness to refer to CAM providers, there is currently little information regarding medical education in these practices. This survey assessed the frequency and nature of alternative medicine instruction in US medical schools and family practice residency programs.

METHODS

Society of Teachers of Family Medicine staff mailed a 16-question survey to all US medical school family medicine department chairs and non-university-based family practice residency program directors about existing instruction in alternative medicine, planned instruction, and educational programs under consideration.

RESULTS

The overall response rate was 77.9% (364/467), with 29.7% (108/364) of all respondents currently teaching, 6.0% (22/364) starting to teach, and 6.3% (23/364) considering teaching some form of alternative medicine. CAM instruction is most common in the Northeast and Rocky Mountain regions. The instruction is predominantly elective (72.2%). Instructional content and methodologies vary widely.

CONCLUSIONS

Alternative medicine has begun to establish a presence in US medical schools and family practice residency programs. Offerings in this diverse subject vary widely in content and format.

How should we research unconventional therapies? A panel report from the Conference on Complementary and Alternative Medicine Research Methodology, National Institutes of Health

Research in unconventional medicine requires a number of different questions to build up a "mosaic" of evidence. Choice of research design depends on the question being asked and is independent of the therapy under investigation. Despite the doubts of some practitioners, randomized trials are of value for determining certain questions in alternative medicine.

Supravital staining of eosinophils

Live eosinophils when mixed with Acridine Orange solution and viewed microscopically using u.v. light show very intense colours of their granules (yellow, orange and red) and green nuclear staining. Their active movement, translocation of granules and degranulation can be observed in vitro. Using this method, live eosinophils can be easily differentiated and enumerated.

Drug-abbreviated infections and development of immunity against Trichostrongylus colubriformis in sheep

A protective immune response without liveweight loss can be induced in sheep against T. colubriformis but results depend on the anthelmintic used and duration of immunizing infections. More than 90% protection was achieved in sheep immunized by three 15- or 7-day oxfendazole abbreviated infections or three 21-day nonabbreviated infections. Only 41% protection was induced by 3-day oxfendazole abbreviated infections. Significantly higher worm burden and faecal egg counts were present after challenge in sheep immunized by 7-day levamizole abbreviated infections compared to 7-day oxfendazole abbreviated infection. Liveweight gains of sheep immunized by 15- and 7-day abbreviated infections were not significantly different than non infected controls. Liveweight loss seemed to be associated with high activity of mucus peroxidase and high numbers of eosinophils in the intestinal lumen. High parasite numbers seemed to be associated with low activity of alkaline phosphatase in mucus. Mucus peroxidase, arylsulphatase, larval migration inhibition of mucus, mucus or serum antibody against L3 excretory/secretory antigen or somatic L3, L4 and adult antigen were not associated with protection.

Immune responsiveness of Romney sheep selected for resistance or susceptibility to gastrointestinal nematodes: field studies

Long-term selection of sheep for resistance to parasite infections may be jeopardized if animals do not retain their normal ability to respond to non-parasite antigens. Therefore the antibody responses to ovalbumin (OVA) and human red blood cells (HRBC), and kinetics of peripheral blood lymphocyte phenotypes were examined in mature grazing sheep, genetically resistant or susceptible to gastrointestinal nematodes. In both lines the HRBC antibody response peaked 2 weeks after the primary injection, 1 week after the second injection and 3 weeks after the second OVA injection. The antibody titres of the resistant line sheep decreased sooner after both primary and secondary injections. The resistant line sheep had higher percentages of CD5+ and CD4+ cells than the susceptible sheep. Two injections of OVA and HRBC did not result in significant alterations in percentages of CD5+, CD4+, CD8+ and CD45R+ lymphocytes in either line. In both lines, the control groups showed a steady increase of 0.29% per week in percentages of T19+ (gamma delta) T cells which was significantly higher than in the antigen injected sheep.

Patent infections of Ascaris suum in pigs: effect of previous exposure to multiple, high doses of eggs and various treatment regimes

Fifty-four crossbred, 4-week-old pigs divided into nine equal groups were used to test whether multiple inoculations with high numbers of A. suum eggs with or without anthelmintic would result in patent infections. All pigs exposed to multiple prechallenge inoculations of 500, 1000, 2000, 5000, 10,000 and 20,000 and challenged orally 2 weeks later with 10,000 eggs harboured adult worms. When prechallenge infections were removed by pyrantel tartrate treatment the animals were more susceptible to challenge than controls not previously exposed to infections. The same drug used from 2 days before until 10 days after the last prechallenge infection eliminated that effect. Pigs subjected to the same multiple egg dosing regimen but given feed containing fenbendazole immediately before, during and for 10 days after multiple dosing developed significantly more adult intestinal worms after challenge than any other group. These worms were, however, significantly shorter than those that developed in any group of pigs. Adult worms from all these groups produced eggs that after embryonation were infective to mice.

Effect of age on homovanillic and 4-hydroxy-3-methoxymandelic acid levels in plasma

The plasma levels of homovanillic and 4-hydroxy-3-methoxymandelic acids have been determined in 524 normal subjects ranging from birth to 49 years of age using a mass fragmentographic method. The mean concentration of homovanillic acid in plasma declines exponentially from the age of 1 day (X = 2342.0 nmol/l, 426.6 ng/ml) to adulthood (X = 60 nmol/l, 10.9 ng/ml). 4-Hydroxy-3-methoxymandelic acid behaves in a similar although not so extreme manner (392 nmol/l, 77.6 ng/ml-50 nmol/l, 10 ng/ml).

Variations in sheep serum conglutinating and haemolytic activity for sheep erythrocytes sensitized by rabbit antibody

Based on conglutinating and haemolytic reactions with sheep erythrocytes (E) sensitized by rabbit antibody (A), three types of sheep sera were encountered. Type 1 sera do not conglutinate or haemolyse sheep E-rabbit A. Type 2 sera failed to conglutinate or haemolytically active. Type 3 sera have both activities. Serum from one type 1 sheep still failed to conglutinate 5 days after venepuncture but was not haemolytically active (i.e., type 2). Some sheep that initially had type 2 sera had, five days after an intraperitoneal injection of yeast cells, sera with conglutinating activity (type 3 sera). Type 1, 2 and 3 sera all had haemolytic activity with human E-sheep A indicator cells. Pooled type 3 sera have the highest conglutinating titres with sheep E-rabbit A after 10 min incubation at 39 degrees C. At this stage, the haemolytic titres were very low. From 10 min, the conglutinating titres decreased whereas the haemolytic titres gradually increased until 80 min. Optimal conglutinating activity required less rabbit A to sensitize sheep E than did haemolytic activity.

Inhibitory activity of heated ewe serum for ewe and ram serum complement

In the presence of an indicator antigen-antibody complex, the complement (C) activity in ewe and ram serum was reduced or abolished by addition of ewe serum that had been heated at 56 degrees C for 10 minutes. Pre-incubation of heated ewe serum at 39 degrees C for 30 minutes with the C source prior to addition of the indicator system or addition at the same time caused similar reductions in C activity. Results from the haemolytic, conglutinating and haemagglutinating activities studied indicate that the ewe serum inhibitor(s) reacts with activated classical or alternative activating pathway components and/or the third component of C (C3). The presence of a potent C inhibitor(s) in ewe serum probably accounts for the low sheep C titres with some assay systems. As the heated ewe serum did not appear to activate ewe or ram C per se, it is more appropriate to regard it as 'inhibitory' rather than 'anticomplementary'.

Conglutination and haemolysis of unsensitized human erythrocytes by bovine serum complement

Unsensitized human erythrocytes (E) were haemolyzed by bovine serum to a titre of 1:16-1:32. In the single dilution beyond the haemolytic endpoint, the cells were conglutinated. In dilutions in which haemolysis occurred, cells were conglutinated before being lyzed. With no or minimal haemolysis, conglutination to 1:32-1:64 occurred in tests using insulin-absorbed serum, serum heated at 50 degrees C for 30 min and in tests incubated at 4 degrees C for 30 min. In two-stage tests, EDTA and Mg2+-EGTA prevented bovine C sensitization of human E for conglutination by bovine serum heated at 56 degrees C for 30 min. EDTA prevented haemolysis, but haemolysis to 1:16-1:32 occurred with serum dilutions containing Mg2+-EGTA. Haemolytic activity was restored to serum heated at 50 degrees C by a factor B-containing fraction. Conglutination and haemolysis were blocked by heating serum at 56 degrees C for 30 min and were reduced to low titres by absorbing serum with zymosan. These results strongly suggest that the conglutination reaction involved the classical activation pathway whereas the haemolytic reaction involved the alternative activation pathway. Thus, with dilutions of untreated or treated bovine serum, two C-dependent reactions and the pathways involved can be demonstrated by using unsensitized human E as an indicator system.

Alternative pathway activation of complement in fetal lamb serum by Trichostrongylus vitrinus larvae

Fetal lamb serum (FLS) complement activated by incubation with Trichostrongylus vitrinus larvae was deposited on the larval surface and its presence was demonstrated by leucocyte and erythrocyte adherence reactions and by analysis of antisera from guinea-pig immunized with the larvae. The complement activation proceeded in the apparent absence of antibody and in the presence of ethylene glycol tetracetic acid (EGTA) or Mg++-EGTA but not ethylenediamine tetracetic acid (EDTA). FLS heated to 50 degrees C for 30 min was inactive, but activity was restored by addition of FLS factor B alone or factor B plus Mg++-EGTA. FLS treated with zymosan or inulin was inactive. These results suggest that this non-immune activation of sheep complement by T. vitrinus takes place via the alternative pathway.

Haemolysis of human erythrocytes heavily sensitized with sheep amboceptor by sheep complement chelated with EGTA or Mg2+-EGTA

Human erythrocytes sensitized with an agglutinating dose of either sheep anti-human erythrocyte antiserum, IgM, slow or fast gamma-globulin antibody are haemolysed by foetal lamb or sheep serum complement (C) in the presence of ethyleneglycoltetraacetic acid (EGTA) or Mg2+-EGTA but not ethylenediaminetetraacetic acid (EDTA) or triethylenetetraminehexaacetic acid (TTHA). Dialysis of the C source against phosphate buffered saline rendered it inactive, but addition of Mg2+ or Mg2+-EGTA restored haemolytic activity. Haemolysis of sensitized erythrocytes took place more rapidly in buffer containing Ca2+ and Mg2+ than in EGTA or Mg2+-EGTA. Heating the C source at 50 degrees C for 30 min or 56 degree C for 3 min abolished haemolytic activity. In the presence of EGTA or Mg2+-EGTA, haemolytic activity was restored to 50 degrees C-heated serum by a CM-cellulose fraction that contained sheep factor B. These results show that sheep C, in the presence of EGTA or Mg2+-EGTA will haemolyse human erythrocytes heavily sensitized with sheep amboceptor. The alternative pathway of sheep C is thought to be involved.

[Reduction in cardiotoxicity of ionic contrast media used in coronary angiography by added calcium--Clinical study (author's transl)]

In 16 patients with CAD, hemodynamic and electrophysiologic side effects were examined following selective coronary artery injections with Urografin 76%, a commonly used ionic contrast medium. A Millar transducer tipped catheter was placed in the left ventricle for continuous pressure recording also during injections. The unmodified contrast medium decreases peak left ventricular pressure (-22 +/- 8%) and dp/dt max (-27 +/- 13%) markedly at injection. With added calcium (22.5 mEq/l) this cardiodepressive reaction becomes diminished to -15 +/- 7% and -13 +/- 8% respectively with high significance (p < 0.001). This positive effect is even more marked using higher volumes of contrast material for injection. In contrast to animal experiments, calcium did not completely compensate the negative inotropic reaction even in higher concentration (33.75 mEq/l). The marked sinus slowing (-29 +/- 14%)--observed in patients and not influenced by the calcium addition--has an additional effect in the sense of a "negative frequency-inotropism" and is responsible for the residual cardiodepressive reaction. An influence on electrophysiologic side reactions can also be observed with added calcium but only in injections with higher volumes of contrast medium. QT-elongation, T-wave changes are reduced significantly. We did not see any unfavorable reactions caused by added calcium. The cardiodepressive side effects on the contractile force by commonly used ionic contrast media can be reduced by adding calcium in the above-mentioned concentration. This may be helpful when studying high risk patients and using high injection volumes.