Retreatment with HBV siRNA Results in Additional Reduction in HBV Antigenemia and Immune Stimulation in the AAV-HBV Mouse Model

BACKGROUND AND AIMS

Treatment with siRNAs that target HBV has demonstrated robust declines in HBV antigens. This effect is also observed in the AAV-HBV mouse model, which was used to investigate if two cycles of GalNAc-HBV-siRNA treatment could induce deeper declines in HBsAg levels or prevent rebound, and to provide insights into the liver immune microenvironment.

METHODS

C57Bl/6 mice were transduced with one of two different titers of AAV-HBV for 28 days, resulting in stable levels of HBsAg of about 103 or 105 IU/mL. Mice were treated for 12 weeks (four doses q3wk) per cycle with 3 mg/kg of siRNA-targeting HBV or an irrelevant sequence either once (single treatment) or twice (retreatment) with an 8-week treatment pause in between. Blood was collected to evaluate viral parameters. Nine weeks after the last treatment, liver samples were collected to perform phenotyping, bulk RNA-sequencing, and immunohistochemistry.

RESULTS

Independent of HBsAg baseline levels, treatment with HBV-siRNA induced a rapid decline in HBsAg levels, which then plateaued before gradually rebounding 12 weeks after treatment stopped. A second cycle of HBV-siRNA treatment induced a further decline in HBsAg levels in serum and the liver, reaching undetectable levels and preventing rebound when baseline levels were 103 IU/mL. This was accompanied with a significant increase in inflammatory macrophages in the liver and significant upregulation of regulatory T-cells and T-cells expressing immune checkpoint receptors.

CONCLUSIONS

Retreatment induced an additional decline in HBsAg levels, reaching undetectable levels when baseline HBsAg levels were 3log10 or less. This correlated with T-cell activation and upregulation of Trem2.

Sustained Liver HBsAg Loss and Clonal T- and B-Cell Expansion upon Therapeutic DNA Vaccination Require Low HBsAg Levels

BACKGROUND

Suppression of HBV DNA, inhibition of HBV surface (HBsAg) production and therapeutic vaccination to reverse HBV-specific T-cell exhaustion in chronic HBV patients are likely required to achieve a functional cure. In the AAV-HBV mouse model, therapeutic vaccination can be effective in clearing HBV when HBsAg levels are low. Using a single-cell approach, we investigated the liver immune environment with different levels of HBsAg and sustained HBsAg loss through treatment with a GalNAc-HBV-siRNA followed by therapeutic vaccination.

METHODS

AAV-HBV-transduced C57BL/6 mice were treated with GalNAc-HBV-siRNA to lower HBsAg levels and then vaccinated using a DNA vaccine. We used single-cell RNA and V(D)J sequencing to understand liver immune microenvironment changes.

RESULTS

GalNAc-HBV-siRNA, followed by therapeutic vaccination, achieved sustained HBsAg loss in all mice. This was accompanied by CD4 follicular helper T-cell induction, polyclonal activation of CD8 T cells and clonal expansion of plasma cells that were responsible for antibody production.

CONCLUSIONS

This study provides novel insights into liver immune changes at the single-cell level, highlighting the correlation between induced reduction of HBsAg levels and clonal expansion of CD4, CD8 T cells and plasma cells in the liver upon HBV siRNA and subsequent therapeutic vaccination.

Acute inhibition of transient receptor potential vanilloid-type 4 cation channel halts cytoskeletal dynamism in microglia

Microglia, the resident macrophages of the central nervous system, are highly motile cells that support brain development, provision neuronal signaling, and protect brain cells against damage. Proper microglial functioning requires constant cell movement and morphological changes. Interestingly, the transient receptor potential vanilloid 4 (TRPV4) channel, a calcium-permeable channel, is involved in hypoosmotic morphological changes of retinal microglia and regulates temperature-dependent movement of microglial cells both in vitro and in vivo. Despite the broad functions of TRPV4 and the recent findings stating a role for TRPV4 in microglial movement, little is known about how TRPV4 modulates cytoskeletal remodeling to promote changes of microglial motility. Here we show that acute inhibition of TRPV4, but not its constitutive absence in the Trpv4 KO cells, affects the morphology and motility of microglia in vitro. Using high-end confocal imaging techniques, we show a decrease in actin-rich filopodia and tubulin dynamics upon acute inhibition of TRPV4 in vitro. Furthermore, using acute brain slices we demonstrate that Trpv4 knockout microglia display lower ramification complexity, slower process extension speed and consequently smaller surveyed area. We conclude that TRPV4 inhibition triggers a shift in cytoskeleton remodeling of microglia influencing their migration and morphology.

A web-based survey of reproductive awareness and choices in women with endometriosis

OBJECTIVE

Our aim was to study fertility issues, attitudes towards reproductive techniques and fertility preservation options in women of reproductive age with endometriosis.

STUDY DESIGN

In 2018 we conducted a web-based survey on fertility issues in women aged 18-40 years with endometriosis. Participants were recruited via advertisements on social media and local endometriosis support groups. Participants completed a self-developed online questionnaire evaluating the following dimensions: sociodemographic, medical data, parental project, knowledge and attitudes toward endometriosis and fertility, means used to access information, and reproductive choices.

RESULTS

The majority of women (96 %) worried about the impact of endometriosis on their fertility. Approximately half of them (52 %) reported having received sufficient information concerning the effect of endometriosis on fertility from their doctor, whereas 31 % had discussed fertility issues with their doctor but desired further information. In contrast, only a minority (27 %) of women considered themselves well-informed on fertility preservation options. Information given by specialists on endometriosis and reproduction was considered most useful. Information mediated through patient support groups was also highly rated, whereas information given by the general gynecologist was less highly rated. The majority of women would consider assisted reproductive techniques (74 %) or adoption (70 %) in case of infertility. Interestingly, 72 % of women would undergo oocyte vitrification for fertility preservation, whereas only 37 % would resort to oocyte donation.

CONCLUSION

This is the first survey to address the topic of fertility issues from the patient's perspective in women with endometriosis. The vast majority of women attach great importance to a discussion about fertility possibilities and only a minority of women consider themselves well-informed. Our results highlight the importance of addressing the issue of fertility in women with endometriosis. Special attention should be given to information and counselling about fertility preservation options since most women consider their knowledge on the topic insufficient. Knowledge and attitudes to counsel endometriosis patients on fertility issues and fertility preservation options should be included in the training curricula of gynecologists. Adequate information on reproductive aging, risk factors for infertility, and reproductive choices, including oocyte vitrification, should be incorporated into follow-up visits for endometriosis patients.

Raw material variability of an active pharmaceutical ingredient and its relevance for processability in secondary continuous pharmaceutical manufacturing

Active Pharmaceutical Ingredients (API) raw material variability is not always thoroughly considered during pharmaceutical process development, mainly due to low quantities of drug substance available. However, synthesis, crystallization routes and production sites evolve during product development and product life cycle leading to changes in physical material attributes which can potentially affect their processability. Recent literature highlights the need for a global approach to understand the link between material synthesis, material variability, process and product quality. The study described in this article aims at explaining the raw material variability of an API using extensive material characterization on a restricted number of representative batches using multivariate data analysis. It is part of a larger investigation trying to link the API drug substance manufacturing process, the resulting physical API raw material attributes and the drug product continuous manufacturing process. Eight API batches produced using different synthetic routes, crystallization, drying, delumping processes and processing equipment were characterized, extensively. Seventeen properties from seven characterization techniques were retained for further analysis using Principal Component Analysis (PCA). Three principal components (PCs) were sufficient to explain 92.9% of the API raw material variability. The first PC was related to crystal length, agglomerate size and fraction, flowability and electrostatic charging. The second PC was driven by the span of the particle size distribution and the agglomerates strength. The third PC was related to surface energy. Additionally, the PCA allowed to summarize the API batch-to-batch variability in only three PCs which can be used in future drug product development studies to quantitatively evaluate the impact of the API raw material variability upon the drug product process. The approach described in this article could be applied to any other compound which is prone to batch-to-batch variability.

Interventions to Improve the Oral Health of People with Dementia or Cognitive Impairment: A Review of the Literature

OBJECTIVE

Oral diseases and conditions are prevalent among older people with dementia and cognitive impairment. While many interventions have been advocated for use in this population, evidence for their effectiveness is unclear. Our objective was to review systematically the content and effectiveness of interventions and implementation strategies used to improve or maintain the oral health of people with dementia or cognitive impairment.

METHODS

Original studies published in English at any time until January 2015 were identified through electronic searches of the Medline, Embase, CINAHL, Scopus and Cochrane databases and hand searches of eligible studies and relevant reviews. Two investigators independently abstracted study characteristics and assessed the methodological quality of eligible studies. Results were presented as a narrative review because significant heterogeneity among included studies precluded a meta-analysis.

RESULTS

The 18 included studies varied considerably in terms of size, scope and focus. Only two studies were identified that had been designed specifically for and examined exclusively in people with dementia or cognitive impairment. All studies were in residential care; none was population-based. While several studies reported positive effects, a number of methodological weaknesses were identified and the overall quality of included studies was poor. The specific outcomes targeted varied across studies but most studies focused almost exclusively on proximal clinical oral health outcomes such as levels of dental or denture plaque. Attempts to measure intervention integrity were limited and there was usually little or no effort to evaluate intervention effects over a sustained period.

CONCLUSION

There is a lack of high quality evidence to support the effectiveness of oral health interventions and implementation strategies for older people with dementia or cognitive impairment. More rigorous, large scale research is needed in this area. Recommendations are provided to improve the overall quality of evaluation in this area. Emphasis must be placed on developing evidence-based, achievable and sustainable oral health strategies if the needs of people with dementia and cognitive impairment are to be met into the future.

[How much do patients know about the possible physical consequences of their eating disorder?]

BACKGROUND

A lack of knowledge about the physical consequences of an eating disorder can be a sign that the patient either denies that there is a problem or minimises the problem; this can result in the patient being reluctant or unwilling to be treated.

AIM

To find out how much patients know about the possible physical consequences of (or the risks involved in) their eating disorder and to check whether they know considerably more after some psycho-education.

METHOD

Sixty-six female patients completed a questionnaire shortly after being admitted to a specialised eating-disorder unit and 44 patients completed the same questionnaire after about a month. In the intervening period patients received some psycho-education about the possible physical consequences of eating disorders. The psycho-education took the form of an interactive group session and a brochure of information.

RESULTS

In general, the patients' knowledge about possible consequences of their illness was reasonably satisfactory (on average, 14 out of 20 questions were correct), although a considerable number of patients answered 11 questions with 'I don't know'. In the second round there was a considerable decrease in the number of 'I don't know' answers, showing that after a month patients' knowledge had improved (17 out of 20 patients now gave positive answers); the answers were independent of the type of eating disorder. One question in particular elicited the largest number of uncertain or incorrect answers, even in the second round; the question was: Can a woman who has never menstruated become pregnant?'

CONCLUSION

It is advisable to assess, in a systematic way, whether patients have adequate knowledge about the physical consequences of an eating disorder. Gaps in patients' knowledge or misunderstandings can then serve as a starting point for a specific type of psycho-education.

[Pathological hoarding by children and adolescents]

BACKGROUND

There is a dearth of knowledge and understanding concerning hoarding by children and adolescents. Psychiatrists need to know more about the phenomenon of hoarding since it can be a marker of psychopathology and it sometimes is symptomatic of a psychiatric disorder.

AIM

To review hoarding from an epidemiological and psychopathological perspective and to discuss it in relation to the developmental aspect of the first object acquisition: the transitional object.

METHOD

We conducted a literature search in PubMed, Medline, PsycINFO and the Cochranedatabase using primarily the search term ‘hoarding', but also in combination with the terms: primates, child, adolescent, psych*, klepto*, transitional object, obsessive-compulsive disorder, collecting and attachment.

RESULTS

Both animals and humans engage frequently in collecting and hoarding. Up to 60% of normally functioning children and adolescents are involved in collecting. A strong emotional attachment to possessions may be a response to an attachment problem. Hoarding combined with psychopathology is seen in persons of all ages but the prevalence rates for children and adults are unknown.

CONCLUSION

Hoarding is a worrisome type of behaviour which must be regarded as an indication of serious comorbid psychopathology. It can occur either as a symptom of an existing disorder or as a separate disorder. Finally we recommend that hoarding be included in the diagnostic criteria of the dsm and icd.

Sexual and psychological functioning in women after pelvic surgery for gynaecological cancer

Pelvic surgery for gynecological cancer can affect sexuality through a number of anatomical, physiological and psychological mechanisms. We aimed to examine the prevalence of sexual dysfunction and psychological functioning in women who underwent pelvic surgery for gynecological cancer. Fifty women who underwent pelvic surgery for vulvar, cervical or endometrial cancer in a gynecological oncology unit completed questionnaires evaluating marital satisfaction (DAS), depression (BDI-II) and sexual functioning (SSFS and an in-house Specific Sexual Problems Questionnaire). Medical records were used to obtain disease-specific data. The control group consisted of 39 healthy age-matched control women attending an outpatient screening clinic. Significantly more women with gynaecological cancer than controls reported sexual problems (83 vs 20%), including decreased desire (76 vs 14%) and impaired vaginal lubrication (42 vs 9%). Pelvic surgery was specifically related to changed intensity of orgasm (43%), reduced vaginal sensitivity (38%), vaginal elasticity (30%), superficial dyspareunia (27%), vaginal narrowing (26%) and shortening (22%). Although no significant differences were found between either group for depression (17% vs 13%) or total quality of the partner relationship, women with a history of gynecological cancer reported significant lower marital cohesion. These results indicate that although the psychological adjustment of women who underwent pelvic surgery seems to be satisfactory, they seem to be at risk for sexual dysfunctions.

Is wheezing associated with decreased sleep quality in Sri Lankan children? A questionnaire study

AIM

To investigate the association between wheezing and impaired sleep in Sri Lankan children, aged 6-12 years; and, to report the prevalence of asthma-related symptoms in these subjects.

METHODS

The International Study of Asthma and Allergies in Childhood questionnaire and a separate sleep questionnaire were completed.

RESULTS

Of 800 originally distributed questionnaires, 652 were analyzed. Wheezing was present in 89 children (14%). Within this group, 66% reported wheezing in the last 12 months. Wheezing children had a significantly higher presence of snoring, restless sleep, nocturnal awakenings and daytime tiredness. Wheezing was found to be independently associated with restless sleep (odds ratio (OR) = 2.4). There was no association between wheezing and difficulties falling asleep, nocturnal awakenings, apneas, and daytime sleepiness and tiredness. After adjusting for possible confounders, the following significant associations were present: snoring and apneas (OR = 1.6), chronic rhinitis and apneas (OR = 1.6), snoring and restless sleep (OR = 3.2), chronic rhinitis and restless sleep (OR = 2.1), and hayfever and daytime tiredness (OR = 4.3). Wheezing was related to an increased risk of snoring (OR = 2.8) and subjects with chronic rhinitis had also an increased risk of snoring (OR = 1.7), adjusting for possible confounders.

CONCLUSION

The sleep of wheezing children was impaired compared with their non-wheezing peers, resulting in an increased prevalence of daytime tiredness. Upper airway symptoms, such as chronic rhinitis or hayfever, should be carefully considered in these children, as they might be responsible for these sleep problems.

Animal evidence for the transgenerational development of diabetes mellitus

The mammalian fetus develops inside the uterus of its mother and is completely dependent on the nutrients supplied by its mother. Disturbances in the maternal metabolism that alter this nutrient supply from mother to fetus can induce structural and functional adaptations during fetal development, with lasting consequences for growth and metabolism of the offspring throughout life. This effect has been investigated, by several research groups, in different experimental models where the maternal metabolism during pregnancy was experimentally manipulated (maternal diabetes and maternal malnutrition) and the effect on the offspring was investigated. The altered maternal/fetal metabolism appears to be associated with a diabetogenic effect in the adult offspring, including gestational diabetes. This diabetic pregnancy in the offspring again induces a diabetogenic effect into the next generation, via adaptations during fetal development. These experimental data in laboratory animals are confirmed by epidemiological studies on infants of mothers suffering from diabetes or malnutrition during pregnancy. It can be concluded that fetal development in an abnormal intra-uterine milieu can induce alterations in the fetal metabolism, with lasting consequences for the glucose tolerance of the offspring in adult life. The most marked effect is the development of gestational diabetes, thereby transmitting the diabetogenic tendency to the next generation again. The concept of fetal origin of adult diabetes therefore is of major significance for public health in the immediate and the far future.

Intra-uterine transmission of disease

Fetal development is dependent on maternal supply of fuels and building blocks. Disturbed maternal metabolism or inappropriate maternal nutrition confronts the fetus with an unfavourable intra-uterine milieu. Structural and functional adaptations occur during development and maturation of organs. Consequences of these fetal alterations persist postnatally and may result in metabolic alterations throughout life. Gestational diabetes can occur in these offspring and transmit the effect to the next generation. These alterations in fetal development can be associated with fetal macrosomia (maternal diabetes) or fetal growth-restriction (maternal/fetal malnutrition). The relation between birth weight and later metabolic disease therefore is U-shaped. Adult metabolic condition is thus to a considerable extent programmed in utero, fetal and neonatal weight being symptoms of disturbed fetal development. This concept of intra-uterine programming of disease is illustrated with a review of epidemiological human studies and experimental animal studies.

Fetal growth restriction and consequences for the offspring in animal models

OBJECTIVE

In the present review we discuss rat models in which intra-uterine growth restriction is obtained through pharmacological (streptozotocin), dietary (global food restriction, low protein diet), or surgical (uterine artery ligation) manipulation of the maternal animal.

METHODS

A MEDLINE search was performed on rat models of intrauterine growth restriction (IUGR), ie, streptozotocin, food restriction, low protein diet, or uterine artery ligation and pregnancy and fetal programming, long-term effects or adult offspring.

RESULTS

We address the impact of the different maternal conditions for the fetal and neonatal development. The rat models we concentrate on were all associated with fetal hypoinsulinemia and intrauterine growth restriction. Both fetus and neonate adapt to the altered perinatal environment. Some of these adaptations may predispose the offspring to the development of insulin resistance, cardiovascular disease, obesity, and even overt diabetes in later life.

CONCLUSION

The adaptations of the fetal metabolism to the altered intrauterine environment have consequences for the offspring, persisting into adulthood and into the next generation.

Lifetime consequences of abnormal fetal pancreatic development

There is ample evidence that an adverse intrauterine environment has harmful consequences for health in later life. Maternal diabetes and experimentally induced hyperglycaemia result in asymmetric overgrowth, which is associated with an increased insulin secretion and hyperplasia of the insulin-producing B-cells in the fetuses. In adult life, a reduced insulin secretion is found. In contrast, intrauterine growth restriction is associated with low insulin secretion and a delayed development of the insulin-producing B-cells. These perinatal alterations may induce a deficient adaptation of the endocrine pancreas and insulin resistance in later life. Intrauterine growth restriction in human pregnancy is mainly due to a reduced uteroplacental blood flow or to maternal undernutrition or malnutrition. However, intrauterine growth restriction can be present in severe diabetes complicated by vasculopathy and nephropathy. In animal models, intrauterine growth retardation can be obtained through pharmacological (streptozotocin), dietary (semi-starvation, low protein diet) or surgical (intrauterine artery ligation) manipulation of the maternal animal. The endocrine pancreas and more specifically the insulin-producing B-cells play an important role in the adaptation to an adverse intrauterine milieu and the consequences in later life. The long-term consequences of an unfavourable intrauterine environment are of major importance worldwide. Concerted efforts are needed to explore how these long-term effects can be prevented. This review will consist of two parts. In the first part, we discuss the long-term consequences in relation to the development of the fetal endocrine pancreas and fetal growth in the human; in the second part, we focus on animal models with disturbed fetal and pancreatic development and the consequences for later life.

Low taurine, gamma-aminobutyric acid and carnosine levels in plasma of diabetic pregnant rats: consequences for the offspring

Gestational diabetes compromises fetal development and induces a diabetogenic effect in the offspring, including the development of gestational diabetes and the transmission of the effect to the next generation. Changes are not limited to glucose and insulin metabolism, and appear to be modulated by alterations at the hypothalamo-hypophyseal axis. In the present work, serum concentrations are given for the non-protein amino-acids taurine and gamma-aminobutyric acid (GABA), both neurotransmitters essential for normal brain development, and for the endogenous neuroprotector carnosine, a known anti-oxydans. Taurine levels are significantly below normal values in mildly diabetic mothers, in their fetal and adult offspring, virgin and pregnant, and in the fetuses of these pregnant offspring. GABA and carnosine levels are at the limit of detection in the diabetic mothers and their offspring at every stage. It is concluded that the low taurine, GABA and carnosine levels in diabetic mothers and their fetuses might compromise the normal structural and functional development of the fetal brain. When adult, these offspring present a deficiency of the circulating levels of these neurotransmitters involved in the hypothalamo-hypophyseal regulation of insulin secretion. This might contribute to the development of impaired glucose tolerance and gestational diabetes, thereby transmitting the effect to the next generation.

Pancreatic islet transplantation in diabetic pregnant rats prevents acquired malformation of the ventromedial hypothalamic nucleus in their offspring

Exposure to a diabetic intrauterine environment leads to diabetogenic disturbances throughout later life in rats. This is accompanied by a fetally acquired dysplasia of the ventromedial hypothalamic nucleus (VMN) which is decisively involved in the regulation of metabolism. We investigated whether malformation of the VMN is preventable by normalization of gestational hyperglycaemia. Correction of hyperglycaemia in pregnant streptozotocin-diabetic rats was achieved by pancreatic islet transplantation. The number of neurons in the VMN was significantly reduced in adult offspring of non-treated, sham-transplanted mother rats (P<0.05), but did not differ between offspring of islet-transplanted mother rats and offspring of control mothers. In conclusion, prevention of VMN malformation in offspring of islet-transplanted diabetic mothers might be co-responsible for normalization of their glucose homeostasis during life.

Long-term consequences for offspring of diabetes during pregnancy

There is evidence that the diabetic intra-uterine environment has consequences for later life. Maternal diabetes mainly results in asymmetric macrosomia. This macrosomia is associated with an increased insulin secretion and overstimulation of the insulin producing B-cells during fetal life. In later life, a reduced insulin secretion is found. Intra-uterine growth restriction is present in severe maternal diabetes associated with vasculopathy. Intra-uterine growth restriction is associated with low insulin secretion and reduced development of the insulin receptors. In later life, these alterations can induce insulin resistance. The long-term consequences of an abnormal intra-uterine environment are of primary importance world-wide. Concentrated efforts are needed to explore how these long-term effects can be prevented.

PROLACTIN-deficiency in adult offspring of diabetic mothers

Maternal diabetes induces fetal alterations, resulting in lasting consequences for the glucose tolerance of the offspring over several generations. In our experimental rat model, circulating prolactin, oestradiol, progesterone and corticosterone levels, known to influence insulin secretion and action, are determined in plasma of female adult offspring of mildly and severely diabetic mothers. Prolactin and progesterone levels are equally low in both groups as compared to controls, stressing the involvement of the CNS in the transgeneration effect; oestradiol and corticosterone levels are normal. No correlation is found between these hormonal alterations and the known differences in glucose tolerance.

Fetal growth and consequences for later life

There is evidence that an abnormal intrauterine environment has consequences for later life. Intrauterine growth retardation is associated with low insulin secretion during fetal life and probably a reduced development of insulin receptors. In later life these alterations can induce insulin resistance. Macrosomia is associated with an increased insulin secretion during fetal life and exhaustion of the insulin producing B cells. In later life a reduced insulin secretion is found. The working mechanisms have been explored in experimental studies. Normalisation of the diabetic intrauterine milieu can prevent consequences in later life. There are also indications that vascular changes in later life can be reduced by anti-oxidantia. In the human intrauterine growth retardation is related in later life with insulin resistance, vascular diseases and preeclampsia; macrosomia is related with gestational diabetes and breastcarcinoma.

Fetal growth and long-term consequences in animal models of growth retardation

Perturbations of the maternal environment involve an abnormal intrauterine milieu for the developing fetus. The altered fuel supply (depends on substrate availability, placental transport of nutrients and uteroplacental blood flow) from mother to fetus induces alterations in the development of the fetal endocrine pancreas and adaptations of the fetal metabolism to the altered intrauterine environment, resulting in intrauterine growth retardation. The alterations induced by maternal diabetes or maternal malnutrition (protein-calorie or protein deprivation) have consequences for the offspring, persisting into adulthood and into the next generation.

Ultrastructural evaluation of B-cell recruitment in virgin and pregnant offspring of diabetic mothers

Adult offspring of diabetic rat mothers display a disturbed glucose tolerance and gestational diabetes. The amount of endocrine pancreas and of B-cells is largely sufficient in these non-pregnant and pregnant youngsters. The present work aims a morphometric evaluation of B-cell activity in adult youngsters from control, mildly and severely diabetic mothers, in basal condition and in their adaptation to pregnancy. B-cells are divided, on basis of the ultrastructural morphology of their organelles, in dark non-activated B-cells and pale activated B-cells. These data are related to the concepts of functional B-cell heterogeneity and dose-dependent recruitment of pancreatic B-cells on stimulation. The recruitment of B-cells in each of the groups is evaluated from the proportion pale/dark B-cells. In control animals this is about 50/50, in both experimental groups there is a marked predominance of pale B-cells. During normal pregnancy, a shift occurs towards a majority of pale B-cells. In the offspring of diabetic mothers, the ratio does not further change during gestation. It can be concluded that the disturbance in B-cell stimulation and the development of gestational diabetes in offspring of diabetic mothers is associated with a maximal recruitment of the B-cells already in basal non-pregnant condition.

The endocrine pancreas in virgin and pregnant offspring of diabetic pregnant rats

Diabetes of the mother during pregnancy induces structural and functional adaptations in the fetal endocrine pancreas. We have previously shown in our experimental rat model, that the impact of this abnormal intra-uterine milieu leads, in the adult offspring, to a disturbance of the glucose homeostasis and to the development of gestational diabetes. The aim of the present work is to investigate wether these functional differences can be explained by structural differences at the level of the endocrine pancreas. Therefore the size and the structure of the endocrine pancreas, as well as the contribution of the insulin-, glucagon-, somatostatin- and PP-cells, were investigated morphometrically in the adult youngsters of mildly and of severely diabetic mothers, since both display a disturbed glucose tolerance but with divergent characteristics. Also the adaptation of their endocrine pancreas to pregnancy was measured and compared to that of a control pregnancy. In the offspring of mildly diabetic mothers, the size of the endocrine pancreas and the distribution of the islets of Langerhans are normal. Also the doubling of the endocrine mass during pregnancy is similar to controls. The high proportion of A-cells, especially in relation to a normal B-cell mass and the low amount of PP-cells, might play a role in the impairment of the insulin response in these animals and in the development of gestational diabetes. In the offspring of severely diabetic mothers a clear hypertrophy of the endocrine pancreas is noted, which is mainly due to the presence of numerous small islets and which does not increase further during pregnancy. In these animals, the size of the endocrine pancreas and of the B-cell mass have reached 'pregnant' values without pregnancy, which coincides with an exaggerated insulin output and peripheral insulin resistance, as during normal pregnancy. No further increase in islet mass is seen during pregnancy, which is associated with gestational diabetes.

The endocrine pancreas in nonimmune hydrops fetalis

OBJECTIVE

Our purpose was to compare the endocrine pancreas of hydropic infants of immune and nonimmune origin.

STUDY DESIGN

A quantitative morphologic study was performed on the pancreas in 10 infants with immune and nonimmune hydrops. The volume density of the endocrine pancreas in the gland was calculated, as was the numerical density of the endocrine cells in the islets. The percentage of the different cell types was measured on immunohistochemical stained slides. Ten normal infants were used as controls.

RESULTS

An increased amount of endocrine tissue and an increased total number of islet cells of immune and nonimmune origin is present in hydropic infants. However, an increased proportion of the insulin-producing B cells is not present.

CONCLUSIONS

The endocrine pancreas in hydrops fetalis of immune and nonimmune origin is equal, excluding hemolysis as the stimulating factor for equilibrated islet overgrowth. Metabolic stimuli, as seen in infants of diabetic mothers, are probably not involved, because they preferentially stimulate the insulin-producing B cells.

In vivo glucose utilization by individual tissues in virgin and pregnant offspring of severely diabetic rats

Adult offspring of diabetic rats or SDF rats are characterized by insulin resistance in the liver and extrahepatic tissues; this insulin resistance does not worsen during pregnancy. In this study, we determined the glucose metabolic index in tissues of anesthetized virgin and pregnant control and SDF rats in basal conditions and during a euglycemic hyperinsulinemic clamp. Tissues comprised insulin-sensitive tissues (five skeletal muscles, diaphragm, and periovarian white adipose tissue) and control tissues (duodenum and cerebrum). In addition, this study measured the GMI of placenta and fetuses. In basal conditions, SDF rats showed a slight decrease (9-29%) in the GMI of skeletal muscles compared with control rats; it was not altered by pregnancy in any of the tissues. During physiological hyperinsulinemia, virgin SDF rats exhibited a 25-70% decrease in the GMI of skeletal muscles compared with control rats; this decrease was not observed in diaphragm, or in adipose tissue in which the GMI was found to be increased. During pregnancy, SDF rats did not show an additional drop in the GMI of skeletal muscles, whereas the GMI of both skeletal muscles and adipose tissue was clearly diminished (25-60%) in control rats. The GMI of skeletal muscles was therefore comparable in pregnant control rats and SDF rats. The placental, but not fetal, GMI was increased by 24% during hyperinsulinemia in control rats; the placental and fetal GMIs, in basal and hyperinsulinemic conditions, were similar in control rats and SDF rats. In conclusion, skeletal muscles, but not white adipose tissue, are involved in the peripheral insulin resistance of the SDF rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Islet transplantation in diabetic pregnant rats normalizes glucose homeostasis in their offspring

Diabetes of the mother during pregnancy induces alterations in the fetus, resulting in impaired glucose homeostasis in the offspring. In youngsters of severely diabetic mothers, during glucose infusion, hyperinsulinemia is associated with hyperresponsiveness of the beta-cells and insulin resistance. In order to normalize maternal metabolism, isolated islets from neonatal rats were transplanted into the vena porta of severely hyperglycemic (Streptozotocin) rats at day 15 of gestation. Strict glycemic control of the mothers was achieved throughout further gestation and lactation. In the adult offspring of these transplanted rats insulin levels during glucose infusion were significantly lower than in the offspring of sham-transplanted diabetic mothers and were not different from controls. The work confirms that the diabetic state of the mother during late gestation (the period of development of the endocrine pancreas and of the insulin-receptor system) is the inducing factor for the abnormal glucose homeostasis in the offspring, and normalisation of the hyperglycemia eliminates these long-term consequences.

Absence of pregnancy-induced alterations in tissue insulin sensitivity in the offspring of diabetic rats

We have previously demonstrated insulin resistance in the liver and peripheral tissues of the adult offspring of rats made diabetic with streptozotocin (SDF rats). In this study, a euglycaemic hyperinsulinaemic clamp was used to test the hypothesis that insulin resistance is further aggravated during pregnancy in SDF rats. Normal pregnancy was accompanied by a decrease in the sensitivity of the liver and peripheral tissues to insulin, with a normal responsiveness to insulin. In SDF rats no further decrease in the sensitivity of peripheral tissues to insulin occurred during pregnancy when compared with non-pregnant rats, and the dose-response curves of the glucose metabolic clearance rate during hyperinsulinaemia were similar in pregnant control and pregnant SDF rats. There was, however, a modest decrease in the sensitivity of the liver to insulin during pregnancy in SDF rats. The normal increase in plasma insulin levels during pregnancy was blunted in SDF rats: this resulted in increased glucose levels in maternal and fetal rats and increased fetal insulin concentrations, features compatible with mild 'gestation diabetes'. In conclusion, gestational diabetes develops in pregnant SDF rats, although there is no further deterioration in peripheral insulin resistance.

Metabolic alterations in adulthood after intrauterine development in mothers with mild diabetes

We studied the long-term effects of maternal diabetes mellitus on the offspring of experimentally induced diabetic Wistar rats. When stressed by an intravenous glucose load, the adult female offspring had impaired glucose tolerance and developed gestational diabetes mellitus when pregnant. Our results show that even mild diabetes mellitus induces an abnormal intrauterine milieu that causes morphological and functional changes in fetal development with consequences for later life.

Morphometric evaluation of B-cell function during glucose infusion in control and hyperresponsive rats

According to their general appearance, the ultrastructural morphology of their organelles and their functional status, B cells can be divided into dark, unresponsive B cells with condensed mitochondria and narrow RER-cisternae, and pale activated B cells with orthodox mitochondria and distended RER. In control rats, during a three hour glucose infusion experiment, there is a shift from a majority of dark B cells to a majority of pale B cells, and a decrease in the proportion of dark and mixed islets in favour of the pale islets. No degranulation however (dark and light granules) occurs. In adult youngsters of severely diabetic mothers, known to be hyperresponsive to glucose stimulation, a more important mass of pale activated B cells is present in basal conditions, and is not augmented by stimulation. Dark and mixed islets are scarce in these animals and some degranulation occurs. The data illustrate that in control and in hyperresponsive rats, the B cells manage very well, to meet the increasing demand of insulin without any signs of exhaustion or damage. The data confirm in vivo, and at the morphological level, the concepts of functional heterogeneity and of dose-dependent recruitment of pancreatic B cells. Moreover functional heterogeneity of islets is suggested.

The effects of maternal diabetes on the offspring

Diabetes in pregnancy has an influence on the development of the fetus. There are strong indications that the intrauterine diabetic milieu has long-lasting consequences. In the rat, mild diabetes during pregnancy induces decreased insulin secretion in later life, whereas severe diabetes is responsible for insulin resistance. In the human, data are available showing a long-term consequence in the offspring of type I diabetes and gestational diabetes mellitus.