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Biomedical subjects

B Rizk

Publications and source records attributed to B Rizk.

At least 37 records · Page 2Linked to original sources
PubMed1991

Ultrasonic transvaginal aspiration of endometriotic cysts: an optional line of treatment in selected cases of endometriosis.

Transvaginal ultrasonically guided aspiration of pelvic endometriotic cysts was performed on 21 patients with recurrent endometriosis after previous surgical treatment. Their main complaint was pelvic pain and infertility. Further conservative surgery was considered a contraindication. The symptoms improved markedly following aspiration. During a 12 month follow-up, reaccumulation occurred in only six cases (28.5%) and the improvement in symptoms persisted in the majority of cases. The technique is simple, safe and effective in the treatment of selected cases of endometriosis.

Adult↗
PubMed1991

Modern management of ovarian hyperstimulation syndrome.

The number of women receiving ovulation induction has markedly increased with the advent of medically assisted reproduction. Consequently, ovarian hyperstimulation syndrome (OHSS) has become a frequent clinical problem. It is a potentially life-threatening situation. In its severe forms it is complicated by haemoconcentration, hypovolaemia, hypotension, acute renal insufficiency and thromboembolism. The pathophysiology of OHSS is poorly understood. The occurrence of OHSS correlates well with the level of oestradiol, the number of follicles, and administration of human chorionic gonadotrophin (HCG). The risk is increased in polycystic ovarian disease. The aim of this paper is to review critically the published literature on prediction, prevention and modern management of OHSS. Complete prevention of OHSS is not possible although several methods are used to predict and reduce its occurrence. Endocrine profile and ultrasonic follicular monitoring are the mainstays of prediction. The presence of a large number of small and intermediate size follicles at sonography is a risk factor. Withholding HCG, continuation of gonadotrophin-releasing hormone analogues and cryopreservation of embryos are optional courses of action for prevention. Mild OHSS is usually self-limiting and requires no active therapy. Moderate and severe cases are treated by correction of fluid and electrolyte imbalance, and by prevention of thromboembolism. The use of surgery is limited to cases of torsion or rupture of ovarian cysts, or the presence of concomitant ectopic pregnancy. Aspiration of the ascitic fluid, preferably by the transvaginal route, is recommended in cases with severe ascites.

Ascitic Fluid↗
PubMed1991

Perinatal outcome and congenital malformations in in-vitro fertilization babies from the Bourn-Hallam group.

The perinatal outcome and congenital malformations in children born between 1978 and 1987 in Great Britain after in-vitro fertilization (IVF) at Bourn Hall Clinic and the Hallam Medical Centre are presented. The average maternal age was 34.2 years. Multiple births were frequent, constituting 23% of all deliveries; 19% were twins and 4% triplets. There were no quadruplet or higher order multiple births during that period. Twenty-five per cent of all deliveries were preterm. The mean birth weight was 2793 g and was strongly related to multiplicity of pregnancy and gestational age. Overall, 32% of babies had a low birthweight (less than 2500 g) with 6% having a very low birthweight (less than 1500 g). The overall stillbirth and infant mortality rates were two to three times higher than those of infants born after natural conception in England and Wales; this is attributed to the high incidence of multiple births. The stillbirth rates were 5.07, 20.8 and 24.7 per thousand total births in singletons, twins and triplets respectively. The corresponding figures for perinatal mortality were 13.5, 38.2 and 37 per thousand. Overall, 2.5% of the babies had one or more major congenital malformations diagnosed within one week of life. This was within the range of expected values in the United Kingdom and there was no significant increase in any specific malformation.

Adult↗
PubMed1990

Rare ectopic pregnancies after in-vitro fertilization: one unilateral twin and four bilateral tubal pregnancies.

Between 1985 and 1989, one unilateral twin and four bilateral tubal pregnancies were encountered among 124 extrauterine pregnancies and 1648 intrauterine pregnancies following in-vitro fertilization and embryo transfer. The two factors associated with this high incidence of single and multiple extrauterine pregnancies were tubal damage and multiple embryo transfer. Embryos at different stages of development appear to have the capacity to implant ectopically. Despite advances in diagnostic capabilities, ectopic pregnancy remains a major cause of maternal mortality. Early diagnosis prior to rupture must be made if mortality and morbidity are to be abolished. The use of transvaginal sonography has improved the diagnosis of ectopic pregnancy and should be routinely used in all pregnancies following assisted conception. The identification of an intrauterine pregnancy should not be sufficient to rule out the possibility of an extrauterine pregnancy or even bilateral tubal pregnancies.

Adult↗
PubMed1990

Ovarian cyst aspiration and the outcome of in vitro fertilization.

This study was designed to ascertain whether any benefit would be derived from aspirating ovarian cysts identified before ovarian stimulation in patients undergoing in vitro fertilization. Thirty-seven patients who had ovarian cysts were categorized into two groups: group A (n = 14) with baseline ovarian cysts and group B (n = 23) with ovarian cysts that developed during pituitary suppression with the gonadotropin-releasing hormone analog. Each group was prospectively randomized into two subgroups depending on whether the ovarian cysts were aspirated or not. In group A, there was a significantly greater number of follicles and oocytes in the ovaries in which cysts were aspirated. However, there was no significant difference in the total number of follicles, oocytes retrieved and fertilized, or in the final outcome. In group B, there was no significant difference in folliculogenesis between the aspirated and nonaspirated subgroups. These observations suggest that the presence of a baseline ovarian cyst may reduce folliculogenesis but do not support routine cyst aspiration if the patient has two functional ovaries.

Adult↗
PubMedDate not supplied

Absence of flow in ovarian vein by time-of-flight magnetic resonance angiography without evidence of thrombosis.

A case of absent flow in the left ovarian vein was diagnosed on time-of-flight (TOF) magnetic resonance angiography (MRA) while investigating for pelvic vein thrombosis in a 53-year-old female. This appearance should not be misdiagnosed as a sign of ovarian vein occlusion or thrombosis. Magnetic resonance imaging (MRI) is a sensitive noninvasive imaging modality in such a clinical setting. Familiarity with the potential pitfalls of different MRA techniques is essential for correct diagnosis. A review of different MRA techniques in evaluation of pelvic venous thrombosis is presented.

Diagnosis, Differential↗
PubMedDate not supplied

Reproductive risks of cocaine.

Cocaine use during pregnancy in the USA has increased dramatically in the past decade, and has resulted in an associated increase in a variety of maternal and perinatal complications. However, a number of confounding factors make it difficult to determine the direct impact of perinatal cocaine use on maternal and fetal outcome. Many substance-abusing women use multiple drugs while pregnant, receive inadequate prenatal care and are predisposed to other health problems that impact on perinatal outcome. As a result of the rapid clearance of cocaine and limitations of available screening methods, the identification of individual users can be difficult. Furthermore, the determination of accurate prevalence rates of cocaine use during pregnancy has been frustrated by sampling bias. Cocaine has profound systemic and cardiovascular effects in both the mother and the fetus, and as a result a number of complications (i.e. fetal malformations, preterm labour, placental abruption) have been attributed to perinatal cocaine exposure. In addition, maternal cocaine use has been associated with a number of neonatal abnormalities, including cardiopulmonary effects, somatic changes and neurobehavioural sequelae. It is estimated that US $500 million dollars in additional health expenditure resulted from increased neonatal hospital costs and longer lengths of stay for cocaine-exposed neonates. This article reviews the reproductive risks associated with prenatal cocaine use. The pharmacology and physiology of cocaine in relation to pregnancy is discussed, and the impact of this substance on the growth and development of the fetus and infant is reviewed.

Abnormalities, Drug-Induced↗
PubMedDate not supplied

The role of vascular endothelial growth factor and interleukins in the pathogenesis of severe ovarian hyperstimulation syndrome.

Ovarian hyperstimulation syndrome (OHSS) is a dramatic complication of ovulation induction. In its most severe form, OHSS is characterized by massive cystic enlargement of the ovaries associated with third space fluid shift, resulting in the formation of ascites and pleural effusion. Ascites developes because of increased peritoneal capillary permeability. In this study we examined the role of vascular endothelial growth factor (VEGF) and interleukins in the pathogenesis of increased capillary permeability. VEGF is a member of the family of heparin binding proteins that act directly on endothelial cells to induce proliferation and angiogenesis. VEGF mRNA and protein are expressed by human ovarian granulosa and theca cells late in follicular development and subsequent to ovulation by granulosa and theca cells. Therefore, VEGF is ideally positioned to provoke the increased permeability of theca blood vessels that occurs shortly before ovulation. Hybridization studies in the rat and primate ovary have demonstrated VEGF mRNA expression predominantly after the luteinizing hormone (LH) surge known to be essential for OHSS. The gonadotrophin-releasing hormone antagonist results in a decreased mRNA expression, implying such expression is dependent on LH. The expression of VEGF mRNA has been recently shown to be enhanced by human chorionic gonadotrophin (HCG) in a dose- and time-dependent fashion. These studies confirm the timely association between VEGF and HCG that has been clinically known for many years to be integral in the development of OHSS. VEGF concentrations in serum, peritoneal fluid and follicular fluid of patients at risk for OHSS have been shown to be significantly related to the development of the syndrome. Furthermore, the kinetics of VEGF in the plasma of patients who actually develop severe OHSS are closely correlated with the clinical course of the syndrome and with certain biological characteristics of OHSS and of capillary leakage, such as leukocytosis and increased hematocrit. Studies on ascitic fluid from patients with sever OHSS have proved that VEGF is the major capillary permeability agent. Incubation with VEGF antiserum decreased the vascular permeability activity by 70%. Interleukin-2 (IL-2) is the first of a series of lymphocytotrophic hormones to be recognized as pivotal for the regulation of immune response. However, hard data to confirm its central role in the pathogenesis of OHSS are still lacking, despite the fact that some preliminary studies suggest a positive association between the pooled follicular fluid IL-2 concentration and the development of OHSS. IL-6 is a mediator of the acute phase response to injury, a systemic reaction characterized by leukocytosis, increased vascular permeability and increased synthesis of acute phase proteins by the liver. Significantly higher serum and ascites IL-6 concentrations were seen in OHSS patients. The immunohistochemical localization pattern suggested that IL-6 is LH or HCG dependent. However, the use of IL-6 as a predictor for the occurrence of OHSS has not been successful. The kinetics of IL-6 in patients with severe OHSS are correlated with the clinical symptoms and the biochemical parameters known to be associated with the severity of the syndrome, suggesting a possible role for IL-6. Further molecular biology studies similar to those performed on VEGF are needed to confirm if this interleukin is central in the cascade of events. IL-8 is a chemoattractant, activating cytokine and a potent angiogenic agent. The peritoneal fluid levels is increased in patients with severe OHSS; its concentration in peritoneal fluid is increased inpatients with severe OHSS. The place of this interleukin in the cascade of events is as yet undetermined and further studies are needed. In conclusion, molecular biology and clinical studies strongly suggest that VEGF is the principal mediator by which HCG might increase capillary permeability in OHSS.

Animals↗
PubMedDate not supplied

Human sperm bioassay has potential in evaluating the quality of cumulus-oocyte complexes.

Human sperm bioassay is routinely used as a quality control check for the culture media. This is one of the three bioassays chosen by the College of American Pathologists (CAP) for interlaboratory proficiency testing to assess the standards of in vitro fertilization (IVF) and andrology laboratories. This study utilized sperm bioassay to assess the quality of cumulus-oocyte complexes (COCs) retrieved in IVF procedures COCs, harvested from the female partner of IVF couples, undergoing identical ovarian stimulation protocols, were individually inseminated with the sperm of the corresponding male partner. Sperm motility in sperm-COC cocultures were compared. Cocultures were established by inseminating the 103 COCs, retrieved from 18 IVF couples with 1 x 10(5) to 2 x 10(5) sperm of the corresponding male partners of the couples. In all 18 cases, the sperm were prepared identically using the Percoll wash method. The cocultures were maintained for 48 h but the oocytes were removed immediately after the fertilization check (approximately 16 h). The motility of sperm in the cocultures and in the insemination stocks were noted and 17 of 18 sperm stocks used for insemination had similar high preinsemination motility (90.2 +/- 5.0%). At 48 h the sperm motility had significantly decreased in the cocultures compared to the insemination stocks; 52.7 +/- 19.9% versus 67.2 +/- 10.4%. There was no difference in the motility among the small, medium, and large COCs (56.4 +/- 24.6%, 52.5 +/- 17.9%, and 50.8 +/- 20.9%, respectively). In 45% of IVF cases, the motility in cocultures varied widely, falling below as well as above that of their corresponding insemination stocks. Furthermore, the sperm motility varied among the cocultures in both pregnant and nonpregnant patients but the extent of variation appears to be greater in the latter. The inter-COC coculture sperm motility variation most likely is due to the differences in the quality of cumulus-oocyte complexes.

Adult↗
PubMedDate not supplied

Fractions of Percoll eliminated sperm: increased sperm yield in percoll wash.

Sperm preparation by Percoll is one of the most widely used techniques, but it has the disadvantage of producing a low final yield of motile sperm. This study compared the quality of Percoll-eliminated sperm with that of Percoll recovered sperm to determine if the profile of the Percoll preparation could be improved. Semen specimens were fractionated by discontinuous Percoll gradient column. This resulted in 4 sperm fractions: sperm retained in the semen (SRS), sperm clumped at the interface of 40 and 80% Percoll (SCI), sperm scattered in the column (SSC), and sperm-forming pellet, called Percoll-recovered sperm (PRS). The sperm fractions were evaluated for count, motility, viability, vitality, and morphology. The SRS exhibited the lowest motility, viability, and vitality (40, 68, and 64%, respectively), which were significantly different from those of SCI, SSC, and PRS. The motility, viability, and vitality differences between SSC and PRS did not reach a statistically significant level. Good motility (grades a and b) was found in SSC (73%) when compared with that of PRS (82%). The lower part of SSC and PRS exhibited identical sperm morphology. The Percoll sperm recovery was 18%, but if SSC is combined with PRS, the total recovery becomes 40%. These data suggest that the SSC fraction, particularly the lower part, which maintains the physical contact with the PRS, can be pooled together to increase the final sperm yield without compromising the quality of the sperm to be used for insemination.

Cell Survival↗
PubMedDate not supplied

Assessment of the relationship of sperm morphology with seminal and other clinical conditions of semen donors.

The occurrence of abnormal forms of spermatozoa in human semen is quite common. According to WHO, semen is considered normal even if it contains 50% morphologically abnormal spermatozoa. This study assessed whether the sperm morphology maintains any relation with the relevant clinical conditions of the semen donor. One hundred samples representing normal and different types of male factor etiologies underwent semen and morphological analysis. Clinical information such as race, age, weight, profession, medication, medical history, and smoking habit of the semen contributors were recorded. The influence of seminal and clinical features on sperm morphology was evaluated with multiple regression analysis. Head abnormalities were more common than tail abnormalities. Acrosomal defects and coiled tails were the most prevalent head and tail abnormalities, respectively. Regression analysis failed to confirm any strong association between sperm morphology and other seminal parameters. Accessory gland-related seminal parameters such as viscosity, volume, pH, and liquefaction showed the least association with the morphological variability. Sperm morphology also showed poor correlation with race, age, weight, smoking habit, and work environment.

Acrosome↗
PubMedDate not supplied

Assessment of the quality of frozen serum by spectrophotometric analysis and sperm bioassay.

Serum is an integral part of media used for in vitro fertilization (IVF) and andrology work. Previous studies showed that the IVF results could benefit if sera were screened for deleterious effects before use. Such screening is impractical when fresh sera are used but may be feasible if the serum is frozen prior to use. This study assessed the impact of freezing on the quality of serum. A total of 158 serum samples, prepared in a university-based andrology-IVF center, were included in the study. The frozen sera were thawed in batches to be used in a series of laboratory experiments. Serum quality was evaluated by spectrophotometric analysis and sperm bioassay under several defined conditions: fresh, frozen, pre- and postfiltration, pre- and postcentrifugation, and the patients' fertility condition. Although all sera were filtered through 0.22-micron filter, more than 10% frozen sera required 0.4- or a combination of 0.8- and 0.4-micron filters before they could be passed through the 0.22-micron filter. Frozen sera that were directly filtrable with a 0.22-micron filter lost 13% turbidity upon filtration. The turbidity of the frozen sera were higher compared to fresh ones as revealed by optical density (OD) and relative light scattering (RLS) spectrophotometry. The freeze/storage-induced spectrophotometric changes did not correlate with the storage time. The centrifugation caused precipitation of sera components. The rate of precipitation of the serum components correlated with the duration of freezing. Spectrophotometric analysis and sperm bioassay did not differentiate the sera of pregnancy-positive and pregnancy-negative subjects. The sperm bioassay failed to detect any biological impact of freezing-induced spectrophotometric changes in the sera, suggesting that the freezing-induced changes did not significantly diminish the serum's capability of supplementing the culture media.

Blood↗