Current Pharmaceutical Design - Volume 11, Issue 6, 2005

Since cervical incompetence was introduced in the English literature in 1678, our understanding and obstetric management of this clinical entity, have changed tremendously over the years. This review shows the historical perspective of the development of cervical incompetence as a distinct clinical entity and an all or nothing phenomenon to cervical incompetence as part of a spectrum leading to preterm delivery, which can express differently in subsequent pregnancies. These changes in our understanding imply consequences for the obstetric management of cervical incompetence. This review focuses on the obstetric management of women considered to be at high risk of preterm delivery due to cervical incompetence, by transvaginal ultrasonographic follow-up of cervical length and transvaginal cervical cerclage.

Preeclampsia still ranks as one of obstetrics major problems. Clinicians typically encounter preeclampsia as maternal disease with variable degrees of fetal involvement. More and more the unique immunogenetic maternalpaternal relationship is appreciated, and as such also the specific ‘genetic conflict’ that is characteristic of haemochorial placentation. From that perspective preeclampsia can also been seen as a disease of an individual couple with primarily maternal and fetal manifestations. Factors that are unique to a specific couple would include the length and type of sexual relationship, the maternal (decidual natural killer cells) acceptation of the invading cytotrophoblast (paternal HLA-C), and seminal levels of transforming growth factor-β and probably other cytokines. The magnitude of the maternal response would be determined by factors including a maternal set of genes determining her characteristic inflammatory responsiveness, age, quality of her endothelium, obesity / insulin resistance and probably a whole series of susceptibility genes amongst which the thrombophilias received a lot of attention in recent years.

New knowledge of placental development and function suggests that several common complications of pregnancy could share a similar origin. It is suggested that impaired placental development in early pregnancy may lead to placental oxidative stress and subsequently to the maternal syndromes such as recurrent early pregnancy loss and preeclampsia. Oxidative stress has been most extensively investigated in pre-eclampsia, resulting in hundreds of publications and many reviews. In general the literature points to the presence of placental and maternal oxidative stress. However, conformity amongst the relevant data is not absolute, most probably the result of the diversity of biomarkers investigated and the methods employed to assess oxidative stress, which generally depend on the assessment of end products of oxidative stress. Recently, new techniques have been developed that use different approaches based on the “real-time” measurement of oxidative stress by the redox status of thiols or the assessment of superoxide generation, whereas the role of Phase I/Phase II biotransformation pathways in oxidative stress was recognised. This review focuses on this biotransformation system, the thiol redox status and the involvement of these systems in oxidative stress associated with reproduction and pregnancy disorders, with the emphasis being laid on the syndrome of pre-eclampsia.

Preeclampsia, intrauterine growth restriction and placental abruption greatly contribute to maternal and fetal morbidity and mortality. Thrombophilia is an inherited or acquired condition that predisposes individuals to venous and/or arterial thrombosis. Recently, three important inherited thrombophilias have been discovered. An inherited mutation in the gene coding for coagulation factor V (factor V Leiden), and a mutation in prothrombin that is associated with higher plasma levels of prothrombin. Both mutations result in an increased susceptibility to develop venous thrombosis. Hyperhomocysteinemia, which is associated with mutations in the gene for methylenetetrahydrofolate reductase, is a risk factor for venous and arterial thrombosis. The presence of antiphospholipid antibodies, an acquired thrombophilic condition, is associated with venous and arterial thrombosis. The term placental vasculopathy, is used to describe pathological placental changes that have been associated with preeclampsia, intrauterine growth restriction, placental abruption and fetal loss. The known thrombotic nature of the placental vasculopathy and the increased thrombotic risk with the presence of thrombophilias suggest, a cause-and-effect relationship between inherited and acquired thrombophilias and a number of severe obstetric complications. Testing patients with these complications for thrombophilias may have therapeutic implications for future pregnancies.

Hypertension is the most common medical disorder during pregnancy [1]. Approximately 70 percent of women diagnosed with hypertension during pregnancy will have gestational hypertension-preeclampsia. The term gestational hypertension-preeclampsia is used to describe a wide spectrum of patients who may have only mild elevation in blood pressure to those with severe hypertension with various organ dysfunctions (acute gestational hypertension, preeclampsia, eclampsia, and the syndrome of hemolysis, elevated liver enzymes, and low platelets (HELLP syndrome). The exact incidence of gestational hypertension-preeclampsia in the United States is unknown. Estimates range from 6% to 8% of all pregnancies [1]. The treatment of hypertensive disorders in pregnancy requires careful assessment of the maternal and fetal conditions. Therapeutic decisions must take into account fetal age, maternal symptoms, tests of fetal well-being, as well as maternal status, in order to ensure the best overall outcome. Treatment of mild gestational hypertension with antihypertensive medications has not been shown to improve outcome, however, in cases of severe disease treatment has been shown to be beneficial. The purpose of this review is to discuss the different treatment modalities used in the hypertensive disorders of pregnancy. Management strategies will not be discussed.

Early postpartum hemorrhage remains a significant cause of maternal morbidity and mortality. Postpartum hemorrhage is most commonly due to uterine atony and often responds to medical treatments such as administration of uterotonic drugs, alone or in combination with uterine massage or bimanual compression. As the incidence of cesarean section continues to rise, the problem of placenta previa and accreta is likely to become more common. For first-line management of postpartum hemorrhage adequate blood and fluid replacement is mandatory. In recent years new therapeutic measures to control the bleeding have gained attention. Although, these newer therapies focus on avoiding the need for emergency hysterectomy and preservation of reproductive function, reports of subsequent pregnancies are still scarce. Established management options are shortly reviewed and novel medical and surgical treatments are more extensively discussed.

Helicobacter pylori is one of the most common pathogenic bacterial infections, colonising an estimated half of all humans. It is associated with the development of serious gastroduodenal disease - including peptic ulcers, gastric lymphoma and acute chronic gastritis. Current recommended regimes are not wholly effective and patient compliance, side-effects and bacterial resistance can be problematic. Drug delivery to the site of residence in the gastric mucosa may improve efficacy of the current and emerging treatments. Gastric retentive delivery systems potentially allow increased penetration of the mucus layer and therefore increased drug concentration at the site of action. Proposed gastric retentive systems for the enhancement of local drug delivery include floating systems, expandable or swellable systems and bioadhesive systems. Generally, problems with these formulations are lack of specificity, limited to mucus turnover or failure to persist in the stomach. Gastric mucoadhesive systems are hailed as a promising technology to address this issue, penetrating the mucus layer and prolonging activity at the mucus-epithelial interface. This review appraises gastroretentive delivery strategies specifically with regard to their application as a delivery system to target Helicobacter. As drug-resistant strains emerge, the development of a vaccine to eradicate and prevent reinfection is an attractive proposition. Proposed prophylactic and therapeutic vaccines have been delivered using a number of mucosal routes using viral and non-viral vectors. The delivery form, inclusion of adjuvants, and delivery regime will influence the immune response generated.

Acute intoxication due to alcohol consumption has been known to elicit reversible skeletal and cardiac muscle dysfunction, or “alcoholic myopathy and cardiomyopathy”. Sometimes, irreversible muscle damage can be induced after heavy alcohol drinking. Many researchers have proposed that acetaldehyde, the major oxidised product of alcohol, may be a primary factor underlying alcohol-induced muscle dysfunction. Because acetaldehyde is rapidly metabolised to acetate by aldehyde dehydrogenase (ALDH) mainly in the liver, blood concentration of acetaldehyde is maintained at a low level even after heavy alcohol intoxication. In alcoholics, blood acetaldehyde level is relatively high, probably due to hepatic inhibition of ALDH activity. Several mM of acetaldehyde have been used for studies of cardiac muscle contraction, the intracellular calcium transient, and the L-type calcium channel. In skeletal muscle, the calcium release channel/ryanodine receptor activity has been reported to be inhibited by exposure to 1 mM acetaldehyde. However, these observations were made using potentially lethal concentrations of acetaldehyde, so the hypothesis that acetaldehyde plays a crucial role on alcoholic myopathy is questionable. In this review, we will summarise the effect of alcohol and its major oxidised product, acetaldehyde, on skeletal and heart muscles and propose a toxic contribution of clinical concentrations of acetaldehyde to alcoholic myopathy. In addition, this review will include briefly the effect of acetaldehyde on diabetic cardiomyopathy.

Vaccines delivered through mucosal surfaces are increasingly studied because of their properties to effectively induce mucosal immune responses, are cheap, easily administrable and suitable for mass vaccinations. The prospects of development of edible and intranasally administered (perhaps through nose drops or spray) vaccines are inciting a lot of interest and generating many studies. One major obstacle is to be able to induce systemic as well as mucosal responses to mucosal vaccines. Apart from immunizing with live viruses, this has proven to be a challenge and one way to overcome it is by using adjuvants. It is well established that toxins with little or no capacity to activate adenylate cyclase and thus lacking toxicity (CT or mutant Echerichia Coli labile toxin) improve performance of mucosal vaccines. Synthetic oligodeoxynucleotides containing immunostimulatory CpG motifs (CpG) have synergistic action with other adjuvants, such as alum and CT when delivered mucosally. There are several other important candidates for use as mucosal adjuvants. The proinflammatory cytokines IL-1α, IL-12, and IL-18 can replace CT as a mucosal adjuvant for antibody induction and induce an increase of mucosal CTL's. IL-15 also has the potential to increase antigen-specific CTL activity when used as an adjuvant while IL-5 and IL-6 were shown to be able to markedly increase IgA reactivity to co-expressed heterologous antigen. Chemokines such as MCP-1 could also be used as potential adjuvant for mucosally administered DNA vaccines as it significantly increases mucosal IgA secretion and CTL responses.