Biofluid Aspects of Embryo Transfer

Embryo transfer (ET) is the last stage of extracorporal fertilization during which the embryo is placed in the uterine cavity with a medium-filled catheter 2–3 days after in vitro fertilization. While fertilization in the laboratory occurs at very high rates (>:90%), the overall success of the procedure (i.e., take home baby) is still very low (<25%) and assumed to be mainly due to implantation failure. A computational model was developed to simulate ET within the uterine cavity by a fluid-filled catheter inserted into a two-dimensional channel with oscillating walls. The results showed that the speed at which the embryos are injected from the catheter dominates the procedure and controls the velocity of their transport within the uterine cavity. ET at excessively high injection speeds may lead to ectopic pregnancies, while uterine peristalsis affects transverse dispersion only during injection at low injection speeds. The presence of the catheter within the uterus does not affect flow patterns downstream of its tip. The potential risks to implantation failure due to mechanical factors involved in the ET processes are discussed. © 2003 Biomedical Engineering Society. PAC2003: 8719-j, 8710+e     

Factors influencing backache following epidural analgesia in labour

262 obstetric patients received epidural analgesia during labour or for delivery. 6-8 weeks post partum they received a postal questionnaire. No association was found between backache and maternal age, height, weight, parity or mode of delivery, operator or difficulty with epidural insertion. However, in women who had had epidural analgesia, post-partum backache was associated with shorter labours. Difficult epidural insertions were more common in short women.     

OXGR1 is a candidate disease gene for human calcium oxalate nephrolithiasis

PurposeNephrolithiasis (NL) affects 1 in 11 individuals worldwide, leading to significant patient morbidity. NL is associated with nephrocalcinosis (NC), a risk factor for chronic kidney disease. Causative genetic variants are detected in 11% to 28% of NL and/or NC, suggesting that additional NL/NC-associated genetic loci await discovery. Therefore, we employed genomic approaches to discover novel genetic forms of NL/NC.MethodsExome sequencing and directed sequencing of the OXGR1 locus were performed in a worldwide NL/NC cohort. Putatively deleterious, rare OXGR1 variants were functionally characterized.ResultsExome sequencing revealed a heterozygous OXGR1 missense variant (c.371T>G, p.L124R) cosegregating with calcium oxalate NL and/or NC disease in an autosomal dominant inheritance pattern within a multigenerational family with 5 affected individuals. OXGR1 encodes 2-oxoglutarate (α-ketoglutarate [AKG]) receptor 1 in the distal nephron. In response to its ligand AKG, OXGR1 stimulates the chloride-bicarbonate exchanger, pendrin, which also regulates transepithelial calcium transport in cortical connecting tubules. Strong amino acid conservation in orthologs and paralogs, severe in silico prediction scores, and extreme rarity in exome population databases suggested that the variant was deleterious. Interrogation of the OXGR1 locus in 1107 additional NL/NC families identified 5 additional deleterious dominant variants in 5 families with calcium oxalate NL/NC. Rare, potentially deleterious OXGR1 variants were enriched in patients with NL/NC compared with Exome Aggregation Consortium controls (χ² = 7.117, P = .0076). Wild-type OXGR1-expressing Xenopus oocytes exhibited AKG-responsive Ca²⁺ uptake. Of 5 NL/NC-associated missense variants, 5 revealed impaired AKG-dependent Ca²⁺ uptake, demonstrating loss of function.ConclusionRare, dominant loss-of-function OXGR1 variants are associated with recurrent calcium oxalate NL/NC disease.     

Comprehensive genetic screening for vascular Ehlers–Danlos syndrome through an amplification-based next-generation sequencing system

Vascular Ehlers–Danlos syndrome (vEDS) is a hereditary connective tissue disorder (HCTD) characterized by arterial dissection/aneurysm/rupture, sigmoid colon rupture, or uterine rupture. Diagnosis is confirmed by detecting heterozygous variants in COL3A1. This is the largest Asian case series and the first to apply an amplification-based next-generation sequencing through custom panels of causative genes for HCTDs, including a specific method of evaluating copy number variations. Among 429 patients with suspected HCTDs analyzed, 101 were suspected to have vEDS, and 33 of them (32.4%) were found to have COL3A1 variants. Two patients with a clinical diagnosis of Loeys–Dietz syndrome and/or familial thoracic aortic aneurysm and dissection were also found to have COL3A1 variants. Twenty cases (57.1%) had missense variants leading to glycine (Gly) substitutions in the triple helical domain, one (2.9%) had a missense variant leading to non-Gly substitution in this domain, eight (22.9%) had splice site alterations, three (8.6%) had nonsense variants, two (5.7%) had in-frame deletions, and one (2.9%) had a multi-exon deletion, including two deceased patients analyzed with formalin-fixed and paraffin-embedded samples. This is a clinically useful system to detect a wide spectrum of variants from various types of samples.     

Intracerebral haemorrhages in surfactant treated neonates with severe respiratory distress syndrome: age at diagnosis,severity and risk factors

Within a randomized European multicentre trial the time of onset, severity and progression of intracerebral haemorrhages (ICH) were investigated prospectively by serial cranial ultrasonography in 343 ventilated infants with severe respiratory distress syndrome (RDS) following instillation of single or multiple doses of a natural porcine surfactant (Curosurf). In 148/343 infants (43%) ICH was diagnosed (grade I or II: 22%, grade III or IV: 21%). In 26 cases (8%) ICH was present on the ultrasound scan prior to surfactant instillation at a median age of 6h. Incidence and severity of ICH was similar after single- or multiple-dose surfactant treatment. Using a logistic regression model the following risk factors predictive of ICH were defined: low birth weight, allocation to certain hospitals, vaginal delivery, Apgar score6, rectal temperature on admission 36°C, primary anaemia, acidosis prior to treatment, RDS grade IV in pre-treatment chest films and poor response to surfactant treatmentOur study provides supportive evidence that multiple doses of Curosurf do not increase the risk for ICH as compared to single-dose administration.A preliminary report of this work was presented at 8th International Workshop on Surfactant Replacement, Oslo, Norway, May 21 1993. The study was supported by grants of the German government (BMFT 93 607 27) and the German Research Council (Deutsche Forschungsgemeinschaft He 2072: 1–2). The surfactant used in the trial was prepared ang tested in Stockholm with the skilful technical assistance of Elin Arvesen, Bim Linderholm. Eva Lundberg, Gunhild Nilsson and Petru Popa (supported by the Swedish Medical Research Council (Project No. 3351) and Oscar II:s Jubileumsfond)Dedicated to the memory of Edgar (Eddi) Laufkötter, one of the most active trial collaborators, who died under tragic circumstances on April 10, 1994.     

Detection of herpes simplex virus DNA in maternal breast milk by in situ hybridization with tyramide signal amplification

In this study we investigated the prevalence of herpes simplex virus 1 (HSV-1) and 2 (HSV-2) in maternal breast milk using the technique of in situ hybridization combined with the sensitive detection system of tyramide signal amplification. Breast milk samples were collected from both breasts of 34 puerperals 4-5 days after delivery. HSV DNA was detected in 16 out of 34 examined breast milk specimens. HSV DNA was found in the milk of both breasts in 10 cases (62.5%), in that of left breast in 4 cases (25%) and in the milk of only the right breast in 2 cases (12.5%). HSV DNA was localized in the nuclei of mononuclear cells and to a lesser degree in the nuclei of epithelial cells. The number of HSV infected cells ranged from a few cells per sample to 20% of cells (mean value 9%, median value 5%). According to HSV typing, we found both HSV-1 and HSV-2 in 11 out of 16 positive cases and HSV-2 only in 5 cases. In conclusion, our findings indicate that HSV-1 and HSV-2 are shed into breast milk in a significant proportion of puerperals and breast-feeding may be an important route for the transmission of these viruses to infants.     

Breast cancer angiogenesis — new approaches to therapy via antiangiogenesis,hypoxic activated drugs,and vascular targeting

Summary Several groups have shown that quantitation of tumor angiogenesis by counting blood vessels in primary breast cancer gives an independent assessment of prognosis. Poor prognosis is associated with high blood vessel counts. We have shown that the rate of cell division in endothelial cells is much higher in breast tumours than in normal breast. Breast cancer cell lines and primary human breast tumours express a wide range of vascular growth factors, including VEGF, placenta growth factor, pleiotrophin, TGF1, acidic and basic FGF, and platelet-derived endothelial cell growth factor. Inhibiting angiogenesis by blocking vascular growth factors would be difficult with highly specific agents, but drugs with a broader spectrum of antagonism may be effective. We have developed several suramin analogues which are less toxic than suraminin vivo but more potent in inhibiting angiogenesis, and these have been developed for Phase I. A combination of anti-angiogenesis agents with drugs activated by hypoxia may also be useful, because anti-angiogenesis alone may not kill cells, whereas activation of hypoxic drugs could synergize.New endpoints may be necessary because inhibition of new blood vessel formation may not cause tumour regression. Thus, the endpoint of stable disease and biochemical assessment of inhibition of angiogenesis may be much more important in therapeutic studies and for drug development in the future. The prognostic importance of angiogenesis suggests that this should be a major new therapeutic target.Presented at the symposium "New Approaches in the Therapy of Breast Cancer", Georgetown University Medical Center, Washington DC, October 1994, generously supported by an education grant from Bristol-Myers Squibb.     

Cimetidine — antacid combination as premedication for elective Caesarean section

The effect of premedication with an oral antacid (magnesium trisilicate), oral cimetidine or a combination of both was studied in 80 patients undergoing elective Caesarean section. Twenty patients served as untreated controls. Seventy per cent of the patients were in the high risk range for acid aspiration Pneumonitis (pH < 2.5 plus gastric coment volume > 25 ml). Antacid therapy was effective in raising pH but the gastric volume remained high in 50 per cent of the patients. Cimetidine was effective in decreasing gastric volume and raising pH but the pH was still <2.5 in two patients. None of the patients given the cimetidine-antacid combination were in the high risk range for acid aspiration Pneumonitis. The combination of an oral dose of Cimetidine 400 mg, three to four hours before the operation followed by 20 ml of magnesium trisilicate one hour preoperatively proved to be the most efficacious regimen for prophylaxsis against Mendelson’s syndrome in elective Caesarean section. Recent reports have suggested that non-particulate antacids (e.g., sodium citrate) may be preferable to particulate antacids such as magnesium trisilicate.     

LONG-TERM ASSESSMENT OF EXTRADURAL ANALGESIA FOR THE RELIEF OF PAIN IN LABOUR. II: SENSE OF "DEPRIVATION" AFTER EXTRADURAL ANALGESIA IN LABOUR: RELEVANT OR NOT?

Ninety-nine mothers who received extradural analgesia, and 95who received conventional methods of analgesia for the reliefof pain in labour, were interviewed at 18–24 months followingdelivery. An increase of about 2% in the proportion of mothersexperiencing a sense of "deprivation" in the long term in comparisonwith the findings recorded immediately after delivery was noted.This was not accompanied by the need to seek psychiatric treatment