Jason M. Mwenda

POTENTIAL INVOLVEMENT OF THE IMMUNE SYSTEM IN THE DEVELOPMENT OF ENDOMETRIOSIS

This article presents an overview of immunological factors and their role in the development of endometriosis, with emphasis on inflammatory cytokines, growth and adhesion factors. Although retrograde menstruation is a common phenomenon among women of reproductive age, not all women who have retrograde menstruation develop endometriosis. The development of endometriosis is hypothesised to be a complex process, which may be facilitated by several factors, including the quantity and quality of endometrial cells in peritoneal fluid (PF), increased inflammatory activity in PF, increased endometrial-peritoneal adhesion and angiogenesis, reduced immune surveillance and clearance of endometrial cells, and increased production of autoantibodies against endometrial cells. Potential biomarkers like cytokines and autoantibodies upregulated during development of endometriosis may be useful in the development of a non-surgical diagnostic tool. Although endometriosis can be treated using hormonal suppression, there is need for non-hormonal drugs, which can inhibit the development of endometriosis and alleviate pain or infertility without inhibition of ovulation. New molecules that modulate immune function in endometriosis should be the targets for future research.

Burden and epidemiology of rotavirus diarrhea in selected African countries: preliminary results from the African rotavirus surveillance network.

Severe rotavirus diarrhea in children <5 years of age is a major public health problem; however, limited regional and country specific data on rotavirus disease burden are available from sub-Saharan Africa. In June 2006, the World Health Organization Regional Office for Africa initiated rotavirus surveillance in selected African countries. With use of standardized methodology developed by the World Health Organization, children <5 years of age who were hospitalized with severe diarrhea were enrolled, and stool specimens were collected for detection of rotavirus strains with use of a commercial enzyme immunoassay. Rotavirus strains were further characterized for G and P types with use of a reverse-transcriptase polymerase chain reaction. From June 2006 through December 2008, rotavirus surveillance was established at 14 sites in 11 African countries. Of 5461 stool samples collected from children enrolled in 8 countries with 1 or 2 complete years of data, 2200 (40%) were positive for rotavirus. Ninety percent of all rotavirus hospitalizations occurred among children aged 3-12 months. Predominant types included G1P[8] (21%), G2P[4] (7%), and P [8] (29%); however, unusual types were also detected, including G8P[6] (5%), G8P[8] (1%), G12P[6] (1%), and G12P[6] (1%). A high percentage of mixed rotavirus infections was also detected. These preliminary results indicate that rotavirus is a major cause of severe diarrheal disease in African children.

Recombinant Human TNFRSF1A (r-hTBP1) Inhibits the Development of Endometriosis in Baboons: A Prospective, Randomized, Placebo- and Drug-Controlled Study

Abstract Endometriosis is associated with chronic inflammation, including an increased macrophage activity with increased secretion of cytokines, such as tumor necrosis factor (TNF) or TNF superfamily member 2, previously known as TNFα. In the present study, we tested the hypothesis that recombinant human TNFRSF1A (r-hTBP1) can inhibit the development of endometriotic lesions in the baboon, an established model for the study of endometriosis. Endometriosis was induced using intrapelvic injection of menstrual endometrium in 20 baboons with a normal pelvis. In the first part of the study, 14 baboons were randomly assigned to subcutaneous treatment with r-hTBP1, placebo, or GnRH antagonist (positive control). In the second part of the study, menstrual endometrium from 6 baboons was randomly incubated with either PBS or r-hTBP1 before intrapelvic seeding. Video laparoscopy was performed 25 days later to document the number, surface area, and estimated volume of endometriotic lesions and adhesions; to calculate the revised American Fertility Society (rAFS) score and stage; and to confirm the histological presence of endometriosis. In the first part, baboons treated with r-hTBP1 or with Antide (Bachem) had a lower endometriosis rAFS score, a lower surface area and estimated volume of peritoneal endometriotic lesions, and a lower histological confirmation rate compared with controls. Because of less adnexal and cul-de-sac adhesions, the number of baboons with endometriosis of stage II, III, or IV was lower among baboons treated with r-hTBP1 or Antide than among controls. In the second part, the surface area of endometriotic lesions was lower, and less severe endometriosis was observed in r-hTBP1-treated baboons. No hypoestrogenic effects were observed in baboons treated with r-hTBP1. In conclusion, r-hTBP1 can effectively inhibit the development of endometriosis without hypoestrogenic effects in baboons.

Uterus transplantation in the baboon: methodology and long-term function after auto-transplantation

BACKGROUND Techniques for uterus transplantation (UTx) have been developed in rodent/domestic animals towards future clinical introduction of UTx to treat uterine factor infertility. The aim of this study was to extend the UTx research into a non-human primate species by developing surgical techniques for uterus retrieval and transplantation in the baboon. METHODS Female baboons (n = 15) underwent surgery, with the initial five animals used for studies of pelvic vascular anatomy. Retrieval surgery included isolation of the ovarian veins and the uterine arteries together with the anterior branches of the internal iliacs. The utero-tubal-ovarian specimen was removed, flushed and kept ex vivo for 2 h when the two arterial ends and two venous ends were anastomosed side-to-side to construct one arterial and one venous end. These were, at auto-transplantation, anastomosed end-to-side to the external iliacs and the animals (n = 10) were evaluated concerning cyclicity and later by laparoscopy/laparotomy. RESULTS The total duration of organ retrieval, backtable preparation and transplantation was around 6 h with an overall ischaemic time of the specimen of about 3 h. One animal died due to cardiomyopathy. Five out of the nine surviving animals resumed cyclicity, as a sign of re-established ovarian function. Only two out of these five animals exhibited resumed menstruation, indicating re-established ovarian and uterine function. Laparoscopy confirmed normal-sized uteri in these two animals. CONCLUSIONS This study demonstrates the feasibility of UTx by vascular anastomosis in a non-human primate species. The low success rate demonstrates the complexity involved in UTx surgery and the need for further methodological developments.

Cyclospora papionis, Cryptosporidium hominis, and Human-Pathogenic Enterocytozoon bieneusi in Captive Baboons in Kenya

ABSTRACT Cyclospora papionis, Cryptosporidium hominis, and Enterocytozoon bieneusi were detected in 42 (17.9%), 6 (2.6%), and 29 (12.3%) of 235 newly captured baboons in Kenya, respectively. Most C. hominis subtypes and E. bieneusi genotypes found have been detected in humans in the area, suggesting that cross-species transmission of cryptosporidiosis and microsporidiosis is possible.

Future directions in endometriosis research

Endometriosis is an important gynecological disease, pathologically defined by the ectopic presence of both endometrial glands and stroma, and clinically associated with pelvic pain and infertility. Our current knowledge of the pathogenesis, pathophysiology of related infertility, and spontaneous evolution is still limited, although endometriosis has been described for many years. Future research in endometriosis needs to focus on pathogenesis studies in the baboon model and on the early interactions between endometrial and peritoneal cells in the pelvic cavity at the time of menstruation. Proteomic and genomic approaches are needed to detect potential differences between eutopic endometrium and myometrium in women with and without endometriosis. Immunomodulatory drugs inhibiting endometriosis-associated pelvic inflammation may offer new medical treatment for endometriosis in the future.

The detection of enteric viruses in selected urban and rural river water and sewage in Kenya, with special reference to rotaviruses

Aim:  To determine the occurrence of eight human enteric viruses in surface water and sewage samples from different geographical areas in Kenya.

The Baboon as a Research Model for the Study of Endometrial Biology, Uterine Receptivity and Embryo Implantation

The process of embryo implantation includes attachment of the embryo to the endometrium and penetration through the epithelial layer, decidualization of the basement membrane, invasion of the uterine stroma and access to blood supply. This implantation process is very different in humans when compared to pigs, cattle or rodents. The process of invasion in humans where the embryo gets embedded in decidual tissue and in spiral arteries is more aggressive, but otherwise similar to the process of implantation and invasion in non-human primates such as rhesus monkeys and baboons. For ethical reasons, it is unacceptable to study directly the process of embryo implantation in women, and to this day, this remains one of the ‘black boxes’ of reproductive science. Indeed for many clinicians practicing reproductive medicine, in fertility centers, the most difficult question and of concern asked by patients is: ‘Why do my healthy appearing embryos not implant: is there a problem with my endometrium or uterus?’ The olive baboon (Papio anubis anubis) is an excellent animal model for reproductive research. In contrast with smaller non-human primates like rhesus monkeys or cynomolgus monkeys, it is possible in baboons to use transcervical uterine probes (curettes, catheters and hysteroscopic equipment) to perform endometrial biopsy, embryo flushing or transfer and hysteroscopy in a non-invasive way. This can be done easily in multiparous baboons during menstruation, but may be more difficult at the end of the follicular phase (maximal perineal swelling impedes vaginal/cervical access) or during the luteal phase (narrow cervix), in nulliparous baboons and in animals with abnormal internal genitals. In this paper we present an overview regarding the potential of the baboon model to study in vivo uterine receptivity and embryo implantation using invasive and non-invasive approaches.

Uterus transplantation in a non-human primate: long-term follow-up after autologous transplantation

BACKGROUND Uterus transplantation (UTx) may provide the first available treatment for women affected by uterine infertility. The present study aimed to further develop a surgical technique for autologous UTx in a non-human primate species and to assess long-term function. METHODS Female baboons (n= 16) underwent autologous transplantation of the uterus with the Fallopian tubes and ovaries, performed with a previously published surgical technique (n= 6, Group 1) or using a modified technique (n= 10; Group 2). The uterine arteries were dissected to the proximal end of the anterior branch (Group 1) or the entire (Group 2) internal iliac artery, and the ovarian veins were dissected to the crossing over the ureter (Group 1) or further cranially to include greater lengths and patches of the cava/renal vein (Group 2). Back-table preparation created common venous and arterial ends with arterial anastomosis either end-to-side to the left external iliac artery (Group 1) or end-to-end to the left internal iliac artery (Group 2). RESULTS Overall short-time survival of the animals was 88% (66% in Group 1 and 100% in Group 2). Of all the operated animals, 75% (66% in Group 1 and 80% in Group 2) resumed ovarian cyclicity. Regular menstruation after UTx was demonstrated only in Group 2 (60%). Menstruating animals (n= 6) were each exposed to timed mating for ≥5 menstrual cycles, but pregnancy did not occur. Adhesions and tubal blockage were seen in post-mortem analysis. CONCLUSIONS The modified UTx model of Group 2 is a safe procedure and shows resumed long-term uterine function in a majority of the animals, although pregnancy could not be demonstrated.

Role of cytokines in the endometrial-peritoneal cross-talk and development of endometriosis.

A clear picture of the dynamic relationship between the endometrium and peritoneum is emerging as both tissues may participate in the spontaneous development of endometriosis. Various adhesion molecules, pro-inflammatory cytokines and chemoattractants cytokines have emerged as central coordinators of endometrial-peritoneal interactions. The peritoneal microenvironment which consists of the peritoneal fluid, normal peritoneum and peritoneal endometriotic lesions may play an active role in the pathogenesis of endometriosis, by harbouring most inflammatory responses that are triggered by the presence of endometrial cells, leading to recruitment of activated macrophages and leukocytes locally. Menstrual endometrium has the ability to bond and invade the peritoneal tissue. In baboons intrapelvic injection of menstrual endometrium permits the study of early endometrial-peritoneal interaction in an in vivo culture microenvironment and can lead to important insight in the early development of endometriotic lesions. In this review, we discuss the roles of the endometrial-peritoneal interactions, not only in disease development but also in the broader process of aetiopathogenesis.