Synthesis of S-linked glycosyl amino acids in aqueous solution with unprotected carbohydrates

[figure: see text] The cyclic sulfamidate 5 was synthesized in 60% overall yield from L-serine benzyl ester. Compound 5 reacted cleanly with the sodium thiolate salt of a variety of unprotected 1-thio sugars in aqueous buffer to afford the corresponding S-linked amino acid glycoconjugates in good yields after hydrolysis of the N-sulfates.

Accuracy of the preoperative diagnosis in 100 emergency laparoscopies performed due to acute abdomen in nonpregnant women

STUDY OBJECTIVE

To assess the validity of preoperative diagnosis in the emergency room in relation to the surgical diagnosis at laparoscopy.

DESIGN

Retrospective study (Canadian Task Force classification II-2).

SETTING

University-affiliated hospital.

PATIENTS

One hundred consecutive nonpregnant women who underwent emergency laparoscopy for acute abdomen between 1997 and 1999. Intervention. Emergency diagnostic laparoscopy.

MEASUREMENTS AND MAIN RESULTS

The preoperative diagnosis was confirmed by laparoscopy in 29 (44%) of 66 cases of ovarian torsion, 9 (82%) of 11 cases of ovarian cyst, and 12 (80%) of 15 cases of bleeding corpus luteum. Unsuspected diagnoses among nonconfirmed cases were ovarian cysts (24), adhesions (5), bleeding corpus luteum (3), degenerative myomas (3), pelvic inflammatory disease (2), and appendicitis (1). The preoperative diagnosis was confirmed by emergency laparoscopy in 56% of all patients. Diagnoses most likely to be predicted accurately were ovarian cysts and bleeding corpora lutea. Ovarian torsion was most difficult to diagnose preoperatively, as it was not confirmed during laparoscopy in over half patients. Ovarian cysts and adhesions were the most common unsuspected findings.

CONCLUSION

Patients and surgeons alike should be aware of difficulty making accurate preoperative diagnoses of acute gynecologic pathologies in the emergency room. (J Am Assoc Gynecol Laparosc 8(1):92-94, 2001)

A randomized prospective comparative study of general versus epidural anesthesia for transcervical hysteroscopic endometrial resection

OBJECTIVE

This study was undertaken to compare general versus epidural anesthesia during hysteroscopic endometrial resection for dysfunctional uterine bleeding.

STUDY DESIGN

In a prospective comparative study, 24 women with abnormal uterine bleeding that was unresponsive to conservative medical management were randomly assigned to undergo hysteroscopic endometrial resection with either general or epidural anesthesia.

RESULTS

The durations of the endometrial resection procedure were similar for women who had general and epidural anesthesia (28.3 +/- 4.2 minutes vs 27.5 +/- 5.4 minutes, respectively). However, there was a statistically significantly lower absorption of distention fluid in women who underwent the procedure with general rather than epidural anesthesia (380.8 +/- 158.2 mL vs 648.3 +/- 157.1 mL, respectively; P < .0005).

CONCLUSION

A significantly lower amount of glycine distention fluid was absorbed during endometrial resection in women who underwent the procedure with general rather than epidural anesthesia.

Expression of a down-regulated target, SSeCKS, reverses v-Jun-induced transformation of 10T1/2 murine fibroblasts

Line 10T1/2 mouse fibroblast overexpressing the v-Jun oncoprotein were morphologically altered, grew into multilayered foci in culture and formed colonies when suspended in agar. The growth rate of the v-Jun-transformed 10T1/2 cells was not changed significantly from that of the untransformed parental cells, but the saturation density of the transformed cultures exceeded that of normal controls by a factor of 2. mRNA extracted from v-Jun-transformed 10T1/2 cells was analysed for differential gene expression with DNA micro-array technology. One of the targets downregulated by v-Jun was identified as SSeCKS (Src-suppressed C kinase substrate). Re-expression of SSeCKS in v-Jun-transformed fibroblasts reversed the transformed phenotype of the cells. Their ability to form foci was reduced to background levels, the number and size of agar colonies was lowered by a factor of 10 and the saturation density was significantly diminished. However, expression of SSeCKS had little effect on the morphology of v-Jun-transformed 10T1/2 cells. These data suggest that the SSeCKS protein has growth-attenuating properties. Down-regulation of SSeCKS may be essential for Jun-induced transformation.

Macrophage colony stimulating factor (M-CSF) within cord blood sera may be partially responsible for the reduced proliferation of cord blood T cells

We show that there are differences in the soluble factors in cord blood (CB) and adult serum and that these differences play a role in T cell function. Thus, the mitogen and alloantigen-specific proliferative response of adult T cells was enhanced with increasing concentrations of adult serum and CB serum, but to a lesser extent with CB serum. In addition, proliferation of T cells induced by stimulation through the T cell receptor alone (via CD3 stimulation), could be enhanced with adult but not CB serum. However, CB serum enhanced the IL-2-specific proliferative response of pure T cells whereas adult serum did not. To determine whether there was an anti-inflammatory cytokine within CB serum which could induce these results, we assayed our serum samples for anti-inflammatory cytokines. IL-13 could not be detected in any serum sample, whereas IL-10 could be detected in adult but not CB serum (P < 0.002). However, there was a significant difference in the levels of macrophage colony stimulating factor (M-CSF) detected in adult and CB serum samples (P < 0.01). M-CSF was detected in 6/7 CB serum samples (mean +/- SD was 3.8 +/- 2.3 ng/ml) and 0/5 adult serum samples. Furthermore, anti-M-CSF antibody restored the reduced allo-response of T cells incubated in CB serum. Thus, M-CSF may act as a suppressor factor in CB serum. Whether this is sufficient to explain the lack of an allo-response by the foetus to the mother, or the reduced graft-versus-host disease when CB is used instead of bone marrow in stem cell transplantation, is yet to be determined.

Naive T cells from cord blood have the capacity to make Types 1 and 2 cytokines

We wanted to determine whether naive T cells could make the Types 1, 2 and 0 defining cytokines Interleukin (IL)-4 and Interferon (IFN)gamma. We show that stimulation of naive T cells (CD3+ CD45RA+) derived from cord blood by phorbol ester (phorbol-12-myristate-13-acetate: PMA) plus lonomycin induced detection of Types 1, 2 and 0 cells. Conversely, when we stimulated the naive T cells through the T cell receptor (with anti-CD3 monoclonal antibody alone) there was no detection of IFNgamma or IL-4 producing cells. Stimulation with PMA and CD3 induced detection of only Type 2 cells. This unexpected finding shows that there is a high frequency of Type 2 cells within the naive T cell population, contrary to previously published reports. The highest percentage of Type 2 naive cells (10.5%) was obtained with 50 ng/ml PMA plus 50 microg/ml anti-CD3. Thus, we have shown that naive T cells derived from cord blood have the capacity to make both Types 1 and 2 cytokines and the frequency of cells producing these cytokines can be greater than 20%, depending on the stimulus used.

Abnormalities of the fetal central veins and umbilico-portal system: prenatal ultrasonographic diagnosis and proposed classification

OBJECTIVES

Anomalies of the fetal venous system are poorly documented and their pathogenesis is not well understood. The present study was undertaken to review the spectrum of fetal central veins and umbilico-portal system anomalies, and to propose a classification system.

METHODS

A 7-year restrospective survey was conducted.

RESULTS

Nineteen fetuses showed abnormal connection between central veins and the fetal heart. Three fetuses showed abnormal connections of the cardinal veins, two of which had interruption of the inferior vena cava, and one had isolated persistent left superior vena cava. Anomalies of pulmonary veins were seen in four fetuses: in two with asplenia syndrome, a vertical confluent pulmonary artery was observed. In a further two cases total anomalous pulmonary venous connections were found. Abnormalities of the umbilical vein (UV) were seen in 10 cases; seven had persistent right UV, and three had a spectrum of anomalies: One had abnormal connections of the UV to the left iliac vein associated with agenesis of the ductus venosus (DV) and hydrops fetalis. One case showed in utero occlusion of the DV by echogenic foci that resulted in a persistent left proximal UV and porto-systemic shunt. One case had obliteration of the DV secondary to in utero fetal hepatic fibrosis. Abnormalities of the vitelline veins or portal system were demonstrated in two cases. One had a left porto-systemic shunt which resolved spontaneously at 3 months of age, and one had secondary partial occlusion of the left portal system with liver echogenicities and direct communication of the UV with the right atrium. None of the 19 cases had an abnormal karyotype or evidence of in utero infection.

CONCLUSIONS

Detection of various fetal vein anomalies in utero is feasible. The anomalies vary according to embryologic precursors or etiology. Two major mechanisms seem to be involved in the genesis of fetal vein anomalies: in most cases primary maldevelopment of the venous system occurs, while in the minority secondary anomalies from possible thromboembolic events or systemic disease may play a role.

Blood money

Foetal blood contains cells that can regenerate all the cellular elements of blood and the immune system (stem cells). This blood can be obtained from the placenta without any harm to mother or baby and is currently used as a successful alternative to bone marrow for paediatric transplantation. Recently, it has been suggested that this blood can be put in storage and used (if needed) for the child that the blood originally came from. This has prompted a commercial interest, leading to both financial and ethical concerns.

Management of women with polycystic ovary syndrome who experienced premature luteinization during clomiphene citrate treatment

OBJECTIVE

To determine the preferred treatment modality in patients with PCOS who experienced premature luteinization during CC treatment.

DESIGN

Prospective randomized study.

SETTING

Tertiary medical center.

PATIENTS

Twenty-two infertile women with PCOS demonstrating premature luteinization during at least two consecutive CC cycles.

INTERVENTIONS

Randomized induction of ovulation either with FSH alone or with GnRH agonist combined with FSH for a single treatment cycle.

MAIN OUTCOME MEASURES

Premature luteinization was defined as serum progesterone >1.5 ng/mL before hCG administration.

RESULTS

Premature luteinization occurred in eight of the 10 patients (80%) in group A and in two of the 12 patients in group B (16.6%). This result corresponds to the higher mean (+/-SD) progesterone level present in group A patients as compared to those in group B (2.0 +/- 1.2 ng/mL vs. 1.2 +/- 0.6 ng/mL, P=0.03). No pregnancies were achieved in group A, whereas the pregnancy rate per cycle observed in group B was 33.3% (4/12). On the day of hCG administration, the maximum mean (+/-SD) estradiol level was significantly lower (P<0.0001) in group A (210.6 +/- 37.9 pg/mL) than in group B (600.3 +/- 253.8 pg/mL). The treatment duration and the number of FSH ampules used did not differ between the groups.

CONCLUSIONS

Pituitary desensitization with GnRH analog in combination with FSH is superior to FSH-only treatment in PCOS patients who demonstrate premature luteinization during CC treatment.

Synthesis and characterization of an anomeric sulfur analogue of CMP-sialic acid

alpha-2,3-Sialyltransferase catalyzes the transfer of sialic acid from CMP-sialic acid (1) to a lactose acceptor. An analogue of 1 was synthesized in which the anomeric oxygen atom was replaced with a sulfur atom (1S). The key step in the synthesis of 1S was a tetrazole-promoted coupling of a cytidine-5'-phosphoramidite with a glycosyl thiol of a protected sialic acid. Compounds 1 and 1S were characterized for their activity in a sialyl transfer assay. The rate of solvolysis in aqueous buffer of analogue 1S was 50-fold slower than that of 1. Analogue 1S was found to be substrate for alpha-2,3-sialyltransferase. The K(m) of 1S was just 3-fold higher than that of 1, while the k(cat) of 1S was 2 orders of magnitude lower compared to 1.

Drug therapy for hyperthyroidism in pregnancy: safety issues for mother and fetus

Hyperthyroidism (thyrotoxicosis) in pregnancy and the child bearing years is usually attributable to Graves' disease. This is an autoimmune condition in which thyroid-stimulating immunoglobulins (TSI) cause hyperthyroidism. As a rule, pregnancy complicates the management of hyperthyroidism, rather than vice versa. However, patients who remain thyrotoxic during pregnancy are at increased risk of maternal and fetal complications, particularly miscarriage and stillbirth. Therefore, bodyweight loss, eye signs and a bruit over the thyroid gland in a pregnant woman warrant thyroid investigation. Investigations should include measurement of serum free thyroid hormone levels [free thyroxine (T4) and free triiodothyronine (T3)] rather than total T4 and T3 levels, because total T4 and T3 levels may be raised in euthyroid pregnancies due to the presence of increased levels of thyroxine binding globulin (TBG). By 20 weeks' gestational age, the fetal thyroid is fully responsive to TSI and to antithyroid drugs. Maternal T4 and T3 and thyrotropin pass across the placenta in small and decreasing amounts as gestation progresses, but thyrotropin releasing hormone, TSI, antithyroid drugs, iodides and beta-blockers are readily transferred to the fetus from the mother. Hyperthyroidism is usually treated throughout pregnancy with an antithyroid drug, preferably propylthiouracil. The smallest dose which controls the disease is given with careful monitoring of free T4 and T3 levels to minimise the risk of fetal hypothyroidism and goitre. Bilateral subtotal thyroidectomy may be an option for a small number of patients with hyperthyroidism in pregnancy.

Can cord blood cells support the cytokine storm in GvHD?

Cord blood has a high number of proliferating hematopoietic progenitors and is therefore used as an alternative source of hematopoietic cells for allogeneic transplantation. In addition there is a wider availability of cord blood and a lower cost of procurement compared to bone marrow. However one of the most interesting immunological benefits of a cord blood transplant that has been proposed is the low severity of Graft versus Host Disease (GvHD). This review aims to address some of the immunological reasons why this may be the case by assessing the role of cord blood cytokines in the cytokine storm of GvHD.

Treatment of rheumatoid arthritis with a DR4/1 peptide

OBJECTIVE

To determine the safety and potential clinical efficacy of primary and booster injections of a DR4/1 peptide in patients with active rheumatoid arthritis (RA) despite methotrexate therapy. METHODS. Subjects with active RA were enrolled in a randomized, placebo controlled, double blind, dose-escalating clinical trial of synthetic DR4/1 peptide containing the shared epitope. The primary injection of the DR4/1 peptide in alum adjuvant was administered at one of 3 doses, 1.3, 4.0, and 13 mg, followed by up to 3 or 4 booster injections every 6 or 8 weeks at the same dose. The primary outcomes were the occurrence of adverse effects and changes in measures of immune function. Clinical efficacy was assessed using the American College of Rheumatology 20% criteria for clinical improvement.

RESULTS

Fifty-three patients were entered into the trial, including 44 who completed the study. In the absence of any observations of a dose response to the DR4/1 peptide injections, the 3 dosage groups were combined for subsequent analysis into 3 groups: patients receiving DR4/1 peptide injections every 6 weeks, patients receiving DR4/1 peptide injections every 8 weeks, and a placebo group. At all doses and each dosing interval the primary and booster injections of synthetic DR4/1 peptide were well tolerated and did not produce any significant changes in lymphocyte counts or evidence of generalized immunosuppression. Analysis of clinical efficacy showed that the 6 week group had trends toward improvement in disease measures.

CONCLUSION

Primary and booster injections of the DR4/1 peptide containing the shared epitope were safe and did not broadly suppress immune function.

Anti-cardiolipin antibodies in fetal blood and amniotic fluid derived from patients with the anti-phospholipid syndrome

The aim of this study was to investigate whether, in patients with antiphospholipid syndrome, anticardiolipin antibodies pass from mother to offspring sera and amniotic fluid. Eleven patients with antiphospholipid syndrome (study group) and 11 healthy controls, matched by maternal and gestational age (control group) were prospectively examined for the presence of anticardiolipin antibodies in the cord blood during labour, and amniotic fluid during vaginal or Caesarean delivery. Three neonates (27.3%) in the study group had anticardiolipin antibodies in the cord blood, while none had them in the control group. Anticardiolipin antibodies were detected in the amniotic fluid in six (54.5%) of the study group pregnancies, compared with none in the control group. No adverse neonatal outcome was noted except for significantly lower (P < 0.0006) mean birth weight in the study group. Anticardiolipin antibodies can pass the placenta and be detected in fetal cord blood and amniotic fluid. This finding might be used in the future for the assessment of pregnancies with antiphospholipid syndrome.

Microemulsion formulation of cyclosporin (Sandimmun Neoral) vs Sandimmun: comparative safety, tolerability and efficacy in severe active rheumatoid arthritis. On behalf of the OLR 302 Study Group

OBJECTIVE

To compare the safety, tolerability and efficacy of the new oral microemulsion formulation of cyclosporin A (CyA; Sandimmun Neoral) and the original CyA formulation (Sandimmun), in patients with severe active rheumatoid arthritis (RA), over a 12-month period.

METHODS

In this double-blind, multicentre study, patients were randomized to treatment with Neoral or Sandimmun, starting with 2.5 mg/kg/day, with dose adjustments after 4 weeks. Primary efficacy criteria included patients' assessment of disease activity. Pharmacokinetic and safety assessments were performed at regular intervals.

RESULTS

Compared with Sandimmun, Neoral showed a consistent trend towards greater clinical efficacy from week 12 onwards, including a significant difference in patients' assessment of disease activity at the study end-points. A significantly lower increase in dose from baseline was observed with Neoral at week 24. Pharmacokinetic assessments at week 24 showed increased absorption and decreased variability with Neoral. No differences in safety were found between treatment groups.

CONCLUSION

These observations indicate that Neoral is as safe and at least as effective as Sandimmun and have important implications for patient management given the increasing role for CyA in the treatment of severe, active RA.

Preferred treatment of infertile women older than 37 years of age who demonstrate premature luteinization in the first evaluation cycle

OBJECTIVE

To evaluate the efficacy of various treatments in abolishing premature luteinization in infertile women over 37 years old who are undergoing ovulation induction.

DESIGN

Prospective, nonrandomized study.

SETTING

Tertiary care medical clinic.

PATIENT(S)

Seventeen infertile women >37 years old in whom premature luteinization was detected during their evaluation (pretreatment) cycle.

INTERVENTION(S)

The patients underwent three consecutive treatment cycles with clomiphene citrate (group A), hMG (group B), and a GnRH agonist plus hMG (group C).

MAIN OUTCOME MEASURE(S)

Premature luteinization, defined as a progesterone/E2 ratio of >1 on the day of hCG administration.

RESULT(S)

Fifteen (88%) of the 17 patients in group A and 13 (76%) of the 17 patients in group B demonstrated premature luteinization. In contrast, only 1 (6%) of the 17 patients in group C had a progesterone/E2 ratio of >1 on the day of hCG administration. The mean (+/-SD) E2 level on the day of hCG administration was significantly higher in group C (1.236 +/- 772.7 pg/mL) than in group A (214.02 +/- 104.46 pg/mL) or group B (412.5 +/- 337 pg/mL).

CONCLUSION(S)

Pituitary desensitization with a GnRH agonist in conjunction with hMG may be of benefit for older infertile women who demonstrate early luteinization in their first evaluation cycle.

Cord blood serum does not increase lymphocyte responses in comparison to adult serum

To date, over 1000 cord blood (CB) transplants have been reported from different centers worldwide and it is generally agreed that CB represents an encouraging alternative to bone marrow (BM) transplantation. There are a variety of reasons for this, however, possibly the two most controversial aspects are (a) whether there is less graft versus host disease (GVHD) with CB compared to BM transplantation, and (b) whether we can use more HLA mismatches with CB transplantation. The major theory regarding the reduced immunological response of CB lymphocytes is that CB T and NK cells are naive and, therefore, not primed for activation. However, the naive phenomena that has been noted in vitro may be bypassed in vivo by unforeseen factors. We show evidence that there are differences in the soluble factors present in CB and adult serum and that these differences play a role in T cell function. Thus, adult serum will enhance both mitogen and IL-2 specific T cell growth whereas CB serum has no effect, suggesting that there is an activation/growth factor present in adult sera, which is absent in CB sera. This work could enable us to identify the molecular mechanisms which are associated with a lower GVHD in CB compared to BM transplanted individuals.

The frequency of Th2 type cells increases with time on peritoneal dialysis in patients with diabetic nephropathy

We have analysed the frequency of cytokine-producing T cells in different dialysis groups (haemodialysis; HD and peritoneal dialysis; PD) over time. Although we saw no difference in type 1 cytokine production (IL-2 and IFN-gamma) in either dialysis group, there was a clear increase in the percentage of T cells spontaneously producing the type 02 cytokines in the PD group (IL-4, r = 0.558, P < 0.05; IL-10, r = 0.527, p < 0.05). Our patient group was carefully selected to include patients with an ongoing autoimmune disease, insulin dependent diabetes mellitus (IDDM) (DN group) and chronic glomerulonephritis (GN), which are common reasons of end stage renal failure. As expected there was no increase in the spontaneous production of either IL-4 or IL-10 in either disease group with patients undergoing HD treatment. However, there was a clear correlation with the frequency of T cells producing IL-4 (r = 0.755, P < 0.05) and IL-10 (r = 0.725, P < 0.05) and time on dialysis in the PD patients with DN, but not those with GN. Much work has suggested that the pathogenesis of IDDM is associated with a Th1 dominated response. We show here that this response is skewed towards a Th2 response after long term treatment with PD. This work demonstrates that the immunological effects of different dialysis modalities on patients with different diseases vary. This may go some way to explain why certain patient groups have more complications with different dialysis modalities.

Laparoscopic detorsion allows sparing of the twisted ischemic adnexa

STUDY OBJECTIVE

To determine the safety and outcome of laparoscopic detorsion in the management of the twisted ischemic, hemorrhagic adnexa.

DESIGN

Retrospective chart review and prospective follow-up (Canadian Task Force classification II-2).

SETTING

University-affiliated hospital.

PATIENTS

Fifty-eight women with twisted black-bluish ischemic adnexa encountered at laparoscopy.

INTERVENTION

Laparoscopic detorsion with adnexal sparing.

MEASUREMENTS AND MAIN RESULTS

All patients had a benign immediate postoperative course. Transient temperature elevation occurred in seven women (12.1%). No signs of pelvic or systemic thromboembolism were detected in any patient. Long-term follow-up included transvaginal ultrasound, which revealed follicular development in the previously twisted adnexa in 54 women; normal macroscopic appearance at incidental subsequent surgery in 9; and in vitro fertilization with retrieval of oocytes from the previously twisted side in 4.

CONCLUSION

Laparoscopic detorsion of the twisted ischemic, hemorrhagic adnexa is a safe procedure with minimal postoperative morbidity and a potential for the ovary to recuperate fully with preservation of normal function. Laparoscopic adnexa-sparing procedures should be performed in place of traditional salpingo-oophorectomy in women with this disorder who desire future fertility. (J Am Assoc Gynecol Laparosc 6(2):139-143, 1999)

Soluble CD8 stabilizes the HLA class I molecule by promoting beta2M exchange: analysis in real-time

Human soluble CD8 (sCD8) is secreted by activated CD8+/- cytotoxic T lymphocytes (CTLs). The immunological role of sCD8 is poorly defined, however. We have studied the influence of sCD8 on HLA class I interactions by real-time analysis. Using an optical biosensor we demonstrated that the binding of sCD8 to HLA-A2 promotes exchange of beta2-microglobulin (beta2m) in order to stabilize the complex. Kinetic analysis showed that sCD8 significantly increased the affinity (K(A)) of HLA-A2 for immobilized human beta2m; from 1.14 +/- 0.04 x 10(9) M(-1) in its absence, to 2.18 +/- 0.21 x 10(9) M(-1) following preincubation with sCD8. This suggests that the sCD8:HLA class I complex is unlikely to be degraded at the cell surface. Even in the presence of exogenous peptide (HLA-A2 specific or nonspecific), sCD8 has a stabilizing influence on the HLA class I molecule. These findings point to an immunosuppressive role for sCD8, because the binding of sCD8 to HLA class I would block the binding site for CTL-bound CD8 and, therefore, interfere with T cell activation and proliferation. This may have particular significance in pathological situations where elevated levels of sCD8 are found in extracellular fluids, and sCD8 may provide an alternative approach for immunosuppressive therapy.

Enhancing the representation of rural areas in the National Medical Expenditure Survey

This study examines the issues associated with enhancing the representation of rural areas in the National Medical Expenditure Survey (NMES). It reviews alternative definitions of rural areas and describes the classification schemes considered for future cycles of the NMES. A review of the NMES sample representation in rural areas and an examination of the analytical capabilities and limitations of the current design for deriving health care estimates of the rural population is provided. The options presented in this article would extend the analytical capacity of the NMES to permit estimates of rural areas of the national classified by census region, by gradations of rural classification, and for individuals residing in rural frontier counties.

Analysis of the cytokine production by cord and adult blood

To date, over 400 human umbilical cord blood cord blood (CB) transplants have been reported from different centres world-wide and it is generally agreed that CB represents an encouraging alternative to bone marrow (BM) transplantation. There are a variety of reasons for this which include the wider availability and easier access of CB compared to BM. In addition it has been suggested that there is a reduced graft-versus-host-disease (GvHD) with CB compared to BM transplantation. The explanations for this implied benefit are numerous, but research into this area is only just beginning. Nevertheless, it is clear that both T cells and natural killer (NK) cells have reduced function when isolated from CB compared to adult and both these cell types have been implicated in GvHD pathogenesis. How and why the function is reduced is yet to be determined. Many laboratories have tried to answer these questions and the majority have done this by comparing the function of lymphocytes obtained from adult blood with those compared with CB. Since cytokine production by a cell is an indication of the cells function it is important to determine the differences between adult and CB with respect to production of these soluble factors. Here, we have reviewed the current research regarding these CB and adult cell comparisons with an emphasise on cytokine production. Our aim is to obtain a clearer understanding of the mechanisms which may be involved in causing a reduced GvHD in CB compared to BM transplantation.

The influence of host factors and immunogenetics on lymphocyte responses to Hepagene vaccination

We have shown that both demographic and immunogenetic factors are involved in the immune responses of Hepagene vaccinated individuals who were persistent nonresponders to 'S' containing hepatitis B vaccines. The HLA-DRB1 0701; DQB1 0202 genotype was found to be associated with a decline of anti-HBs antibodies (anti-HBs) and were frequent in those individuals who remained nonresponders following booster vaccination. Contrary to previously published 'S' vaccination data, Hepagene stimulated T-cell responses showed a lack of correlation with the humoral responses. Limiting dilution analysis demonstrated that the cellular immune response is associated with the kinetics of exposure to Hepagene rather than magnitude of the anti-HBs response. It remains that despite the inclusion of the pre-S proteins 74% nonresponder vaccinated individuals failed to produce > 100 IU/l of anti-HBs. However, these were persistent nonresponders and it was therefore encouraging that two doses of Hepagene did seroconvert (> 10 IU/L) 61% of this difficult group.

Heterodimers of the SnoN and Ski oncoproteins form preferentially over homodimers and are more potent transforming agents

sno is a member of the ski oncogene family and shares ski 's ability to transform avian fibroblasts and induce muscle differentiation. Ski and SnoN are transcription factors that form both homodimers and heterodimers. They recognize a specific DNA binding site (GTCTAGAC) through which they repress transcription. Efficient homodimerization of Ski, mediated by a bipartite C-terminal domain consisting of five tandem repeats (TR) and a leucine zipper (LZ), correlates with efficient DNA binding and cellular transformation. The present study assesses the role of SnoN homodimerization and SnoN:Ski heterodimerization in the activities of these proteins. Unlike Ski, efficient homodimerization by SnoN is shown to require an upstream region of the protein in addition to the TR/LZ domain. Deletion of the TR/LZ from SnoN decreases its activity in transcriptional repression and cellular transformation. When co-expressed in vitro, c-Ski and SnoN preferentially form heterodimers. In vivo, they form heterodimers that bind the GTCTAGAC element. Tethered Ski:Sno hetero-dimers that lack TR/LZ domains are more active than either their monomeric counterparts, tethered Ski:Ski homodimers or full-length SnoN and c-Ski. This work demonstrates, for the first time, the differences between dimer formation by Ski and SnoN and underscores the importance of dimerization in their activity.

Human leukocyte antigens influence the immune response to a pre-S/S hepatitis B vaccine

In this study we investigated the effects of a single pre-S/S (Hepagene) revaccination in a large population of multiple 'S' vaccinated anti-HBs antibody nonresponder individuals (< 3 IU/l). We investigate the influence of vaccine dose (5, 10, 20 and 40 micrograms/ml), number of previous 'S' containing vaccinations and the individuals HLA genotype on both B- and T-cell responses. We show that 76% of persistently nonresponder individuals produce anti-HBs antibody (> 3 IU/l) following a single revaccination with Hepagene. This anti-HBs antibody response was dose dependent. The group that received 5 micrograms/ml of Hepagene vaccine produced significantly less anti-HBs antibody than those receiving 10, 20 and 40 micrograms/ml doses (p < 0.05 in all cases). Individuals homozygous for HLA-DRB1*0701; DQB1*0202 failed to produce > 100 IU/l of anti-HBs antibody, whereas, heterozygous individuals required > 10 micrograms/ml Hepagene vaccine. The T-cell responses to Hepagene were exclusive of the dose and magnitude of anti-HBs antibody responses. There was a trend towards increased stimulation indices in those individuals who received repeated 'S' containing vaccines. We have clearly shown that the immune response to Hepagene is influenced by the HLA genotype of the individual. However, further investigation is required to determine the specific role of these molecules in hepatitis B vaccine nonresponse. Hepagene is a registered trademark of Hedeva Pharma Ltd.

Effect of renal dialysis therapy modality on T cell cytokine production

INTRODUCTION

Dialysis has been associated with acute changes in the complement activation status, granulocyte markers, macrophage function, T cell activation and the release of pro-inflammatory cytokines. The most common analysis of cytokine production in patients on dialysis has focused on the changes in monokines (particularly IL-1 and TNF alpha), however it is becoming clear that T cell cytokines play a major role in the impaired lymphocyte function of dialysis patients.

METHODS

To assess the effect of dialysis modality on T cell function we analysed the ability of T cells within peripheral blood mononuclear cell populations (PBMC) to produce cytokines after mitogen (phorbol-12-myristate-13-acetate; PMA and lonomycin; I) stimulation in patients on peritoneal dialysis (PD) compared to low flux haemodialysis (HD) and normal individuals (controls).

RESULTS

In control PBMC, PMA + I stimulation significantly increased the percentage of CD3+ cells expressing IL-2, IFN gamma, TNF alpha, IL-4 and IL-10, as expected. However, although mitogen stimulation significantly enhanced the percentage of the classical Th1 cytokines (IL-2, IFN gamma and TNF alpha) in the low flux HD PBMC, it had no effect on CD3+ IL-2 or CD3+ TNF alpha producing cells in the PD group. In contrast, the percentage of T cells producing Th2 cytokines (IL-4 and IL-10) could not be consistently enhanced by mitogen in either dialysis group.

CONCLUSIONS

We suggest that PD alters the ability of T cells to produce cytokines, possibly by causing an 'exhaustion' of the Th1 cells, thereby preventing cells to produce cytokine on ex vivo stimulation. Furthermore, since T cells from both low flux HD and PD groups could not be induced to produce Th2 cytokines we suggest that uraemia or dialysis per se inhibits T cells from producing Th2 cytokines.

A domain necessary for the transforming activity of SnoN is required for specific DNA binding, transcriptional repression and interaction with TAF(II)110

sno is a member of the ski oncogene family and shares ski's ability to transform avian fibroblasts and induce muscle differentiation. Ski and Sno are nuclear proteins that form homodimers and heterodimers. Ski activates transcription of cellular and viral enhancers and we have identified a DNA binding site (GTCTAGAC) through which it represses transcription. In this work, we show that SnoN binds this site and represses transcription of reporters with this binding site as an upstream element. Using fusions with the Gal4-DNA binding domain in a heterologous reporter assay, we identify a tripartite repression domain in SnoN. A 107 amino acid stretch of the SnoN repression domain, that contains two of the subdomains, is closely related to the minimal region of Ski required for transformation. The third subdomain is unique to SnoN. By analysing deletions involving each of the subdomains, we show that subdomains II and III are also required for DNA binding and cellular transformation. We provide evidence for a quenching mechanism of transcriptional repression by which subdomain II binds to TAF(II)110.

Hepatitis B third-generation vaccines: improved response and conventional vaccine non-response--evidence for genetic basis in humans

The lack of response to hepatitis B vaccination remains a problem for those individuals directly at risk of hepatitis B infection, particularly those who work in the health care industry. The factors associated with non-response to hepatitis B vaccination have been investigated in 86 non-responder health care workers who had received multiple 'S' vaccinations without sustained production of anti-HBs. This group received a recently developed hepatitis B vaccine, Hepagene, which included proteins derived from the envelope region of HBV, not present in currently licensed vaccines. The pre-S1 and pre-S2 proteins were included in Hepagene in order to circumvent anti-HBs non-responsiveness which had previously been demonstrated in the inbred mouse model. The inclusion of these additional proteins in Hepagene enabled some seroconverion, from non-responder to responder; however, a proportion of the vaccinees remained non-responders and the reasons for this have been investigated here, with reference to HLA alleles and the demographic predisposition. Here the mechanisms that underlie hepatitis B vaccine non-response have considered the distribution of HLA alleles, age, sex, height and weight in addition to the T-cell responses to Hepagene derived antigens.

Progression of labor in twin versus singleton gestations

OBJECTIVE

The aim of this study was to investigate whether labor curves of twin gestations differ from those of singleton gestations.

STUDY DESIGN

Among 1821 twin deliveries at our institution (1984-1996), we found 69 nulliparous and 94 multiparous women who were delivered at term (>/=37 weeks) of a vertex twin A with a birth weight of >/=2500 g. We excluded women who had any of the following: induction of labor, oxytocin augmentation, cervical dilatation >6 cm on admission, tocolysis during the previous 14 days, height <150 cm, hypertension, and diabetes. Women with singleton gestations (n = 163) who met the same exclusion criteria were matched for parity and maternal age (+/-3 years). Stage 1 of labor was defined as the interval between 4 and 10 cm cervical dilatation. Kaplan-Meier survival analysis was used for comparison between the groups.

RESULTS

The study and control groups were similar in mean maternal height; however, women with twins were significantly heavier than were those with singletons (79.3 +/- 11.2 kg vs 73.2 +/- 10.8 kg, P <.001), had a higher frequency of epidural anesthesia (82% vs 62%), and had a significantly lower birth weight of the presenting fetus (2779.1 +/- 242.5 g vs 3301.4 +/- 429.2 g, P <.001). The cervical effacements and vertex stations on admission were similar in the 2 groups. On admission the cervical dilatation of women delivered of twins was smaller than that of the control group. Twin gestations had a significantly shorter first stage of labor than did their matched singleton control gestations (3.0 +/- 1.5 hours vs 4.0 +/- 2. 6 hours, P <.0001). This difference was apparent only in nulliparous women. No statistical difference was noted in the mean length of the second stage of labor (0.8 +/- 0.5 hour for twins and 0.7 +/- 0.6 hour for singletons).

CONCLUSION

Twin gestations have a significantly shorter first stage of labor than do singleton gestations. This difference may be the result of the birth weight of the presenting twin being lower than that of its singleton counterpart or to differences in uterine contractility in twin and singleton gestations. Different labor curves should be considered for managing twin deliveries.

Real-time analysis of cell surface HLA class I interactions

Characterisation of the kinetics of assembly and dissociation of the HLA class I heterotrimeric complex provides valuable insights into the relative contributions of each element to complex stability. However, to date there has been no real-time binding analysis on whole cells. Here we have developed an optical biosensor model to investigate the binding of class I HLA complexes on whole cells to human beta 2-microglobulin (beta 2m) and the effects of different HLA-specific peptides on this binding. We immobilised beta 2m on an IAsys biosensor surface and established conditions to analyse the binding of this to HLA-A2 expressing cells (T2 cells). Using 721.221 cells as an HLA negative control we showed that HLA-A2 binding was optimal using a) a carboxymethylated dextran surface and b) no growth factors or supplements in the culture medium at the binding event. Using these conditions we verified specificity of binding by inhibition of the reaction with free beta 2m and determined the dissociation rate constant for T2 cell binding to beta 2m (0.03 s-1). In addition, we demonstrated the ability of different HLA specific peptides to modulate cellular HLA-A2 binding to beta 2m. This is the first time that interactions of cell surface HLA class I molecules has been investigated using real-time analysis. Furthermore, our peptide analysis has shown that this model can be used to characterise peptide specific HLA-binding responses on the whole cell surface in real-time.

Mild ventriculomegaly detected in utero with ultrasound: clinical associations and implications for schizophrenia

The most consistent structural abnormality of the brain associated with schizophrenia is that of mild enlargement of the lateral cerebral ventricles. Mild ventriculomegaly (MVM) of the fetal brain detected in utero with ultrasound is associated with developmental delays similar to those described in children at high risk of schizophrenia. Fetal mild ventriculomegaly may be a marker for increased risk of schizophrenia and other neurodevelopmental abnormalities. Given the association between schizophrenia and obstetrical complications, pre- and perinatal complications and pregnancy outcomes were retrospectively reviewed in 51 pregnancies in which the fetus exhibited mild ventriculomegaly on routine ultrasonography and 49 control pregnancies. Mothers of children with MVM were older than controls and had shorter gestations. There were no significant between-group differences in numbers of pregnancy complications or pregnancy outcomes as reflected in gestational age at birth, birthweight, or Apgar scores. Children with isolated mild ventriculomegaly tended to be male. This study indicates that isolated mild ventriculomegaly detected in utero is not associated with pregnancy complications and suggests that isolated mild ventriculomegaly of the fetus is genetically determined or caused by environmental events not routinely considered pregnancy complications.

A quantitative study of the flexibility contributed to RNA structures by nicks and single-stranded gaps

Disulfide crosslinking via thiol-disulfide interchange was applied to quantitate the relative flexibility contributed by nicks and single-stranded gaps in an RNA structure. An RNA duplex comprised of three strands was constructed containing the disulfide crosslink precursors 1 and 2 at opposite ends of the duplex on opposite strands. The third strand was of varying length to yield a nick or single-stranded gaps of 1, 2, or 3 nt. Crosslinking rates Indicated relative flexibilities of the resulting two-helix junctions. Crosslinking in the nicked duplex occurred two orders of magnitude slower than in a duplex containing a 3-nt gap. Rates of crosslinking in duplexes with 3-and 2-nt gaps showed only modest dependence on the gap sequence. Many natural RNAs, including ribozymes, contain two-helix junctions related to the model system described here. The data suggest that two-helix junctions containing a nick in one strand will retain substantial rigidity, whereas one or more single-stranded nucleotides at a two-helix junction allow significant flexibility.

The immunological properties of cord blood: overview of current research presented at the 2nd EUROCORD workshop

It is generally agreed that cord blood (CB) transplantation represents an encouraging alternative to bone marrow (BM) transplantation. There are a variety of reasons for this, the two most controversial being (1) whether there is less graft-versus-host disease with CB compared to BM transplantation and (2) whether we can use more HLA mismatches with CB transplantation? If these are true then CB may generate a lower 'immunological response' compared to transplantation with adult cells. Why this may be is unknown, however, recently there has been much work which compared the immunological function of CB and adult monocytes. Here, we highlight the major contributions from 'The Immunological Properties of CB' session at the 2nd EUROCORD workshop which tried to determine why the immunological response in CB may be lower than that of the adult.

Foetal lymphocytes are more sensitive to freezing than adult lymphocytes within a mononuclear cell environment

Previous studies have reported reduced natural killer (NK) cell activity in cord blood (CB) compared to adult blood mononuclear cell populations. We suggest that foetal NK cells have the capacity to kill, but this is suppressed in vitro. This hypothesis is strengthened by our observation that CB mononuclear cell populations had their NK activity restored by freeze/thawing, whereas adult PBMC had a reduced killing ability on freeze/thawing. Thus, either NK cells are activated to kill by the freeze/thawing or there is an NK cell suppressor factor in CB which is lost through freeze/thawing. This report shows clear differences between NK cells within the adult periphery and CB, and may help toward a better understanding of events occurring in vitro.

The influence of exogenous peptide on beta2-microglobulin exchange in the HLA complex: analysis in real-time

We used an optical biosensor to determine the relative binding affinity of peptides to purified HLA class I molecules. In this assay we monitor beta2-microglobulin (beta2m) exchange within the HLA-A2 molecule, whereby native beta2m in the complex is replaced by beta2m immobilized at the surface of the biosensor. Quantitative kinetic measurements permit us to obtain association rate (kass), dissociation rate (kdiss) and affinity constants (KA) for the beta2m exchange reaction, alone, (control) and in the presence of exogenous peptide. We tested a panel of six peptides which had been designed and synthesized with an HLA-A2 binding motif, and had also been tested by the T2-cell binding assay, along with control peptides. The biosensor results demonstrate that exogenous peptide influences the dynamics of beta2m exchange in a sequence-specific manner. Five of six peptides increased the association rate, decreased the dissociation rate, and significantly increased the affinity (KA=1. 55-1.88x10(9) M-1) of HLA-A2 for immobilized beta2m compared with the control (KA =1.14+/-0.04x10(9)M-1), demonstrating stabilization of the complex. One peptide was unable to stabilize the complex, as also shown in the T2 binding assay. However, analysis of peptide sequences demonstrated that the HLA-A2 secondary motif as well as primary motif residues are required for HLA-A2 stabilization. Further experiments demonstrated that beta2m exchange alone cannot stabilize the HLA class I complex at the cell surface until a peptide of sufficient binding affinity is bound. Hence kinetics equal to or below the control values in our biosensor assay probably represent an unstable complex in vivo. Unlike other methods described for the analysis of peptide stabilization, this approach is significantly faster, provides full kinetic analysis, and is simpler, since it requires no labeling of peptides. Furthermore, this may have important implications in the assessment of peptide vaccines.

Immunological and functional differences between cord and peripheral blood

It is generally agreed that cord blood (CB) transplantation represents an encouraging alternative to bone marrow (BM) transplantation. There are a variety of reasons for this, the two most controversial being (1) whether there is less graft-versus-host disease (GVHD) with CB compared to BM transplantation; and (2) whether we can use more HLA mismatches with CB transplantation? If these are true then CB may generate a lower 'immunological response' compared to transplantation with adult cells. Why this may be is unknown, however recently there has been much work which compared the immunological function of CB and adult monocytes. This work may begin to explain some of the differences we see with different transplants. The most common explanation for reduced CB cell function is that it is naive since, compared to adult mononuclear cell populations, there are (a) higher levels of CD4+ CD45RA+ cells; (b) lower antigen and mitogen specific T cell proliferation; (c) lower cytokine production on stimulation; and (d) a more polyclonal T cell receptor repertoire compared to adult blood. However, lymphocyte naiveté may not be the only answer since it is possible these naive phenomena, noted in vitro are bypassed in vivo. We have evidence that there are differences in the soluble factors secreted into the serum which altered the function of cord and adult lymphocytes. We have analysed the effect of heat-inactivated sera on the function of T cell proliferation by looking at the mitogen and cytokine-specific proliferative responses. Using adult peripheral blood mononuclear cells we show that adult sera will enhance the proliferative responses whereas CB sera has no effect. These results suggest that there is a factor within mature serum which is absent in foetal serum. This factor is, in part, responsible for the proliferation of T cells and its absence could explain the reduced proliferative responses of CB compared to adult T cells. Furthermore, it may shed some light on preliminary observations that CB transplantation gives rise to a low incidence of GVHD.

Fetal natural killer cell function is suppressed

Previous studies have reported reduced natural killer (NK) cell activity in cord blood (CB) compared with adult blood mononuclear cell populations. Using a non-radioactive killing assay, we have verified these findings suggesting that either the fetal NK cell function is suppressed or that these cells are functionally immature. We have shown that CB NK cells are functional, since activating them with cytokines known to activate adult NK cells [interleukin-2 (IL-2), IL-12 and IL-15] increased activation. However, resting the cells, which enhanced adult NK cell activity (P < 0.01), had no effect on fetal NK cells (P = 0.2). These results suggested that fetal NK cells have the capacity to kill, but this is suppressed in vitro. This hypothesis was strengthened by our observation that eight of nine CB mononuclear cell populations had their NK activity restored by freeze-thawing, whereas four of five adult peripheral blood mononuclear cells had a reduced killing ability on freeze-thawing. Freeze-thawing removes a population of cells that suppresses CB NK cell function. To determine which was the case we performed extensive phenotypic analysis of the CB populations pre- and post-freezing and found that the percentage of the CD3- CD56+ population within CB increased significantly (P < 0.0005 by paired t-test) with freezing, whereas freeze-thawing had no effect on this population within a normal adult peripheral blood mononuclear cell population. Our data suggest that within CB there is a population of cells, as yet undefined, which may be inhibiting NK cell function. This report therefore shows clear differences between NK cells within the adult periphery and in CB, and may lead to a better understanding of events occurring in vivo.

High affinity dimerization by Ski involves parallel pairing of a novel bipartite alpha-helical domain

c-Ski protein possesses a C-terminal dimerization domain that was deleted during the generation of v-ski, and has been implicated in the increased potency of c-ski in cellular transformation compared with the viral gene. The domain is predicted to consist of an extended alpha-helical segment made up of two motifs: a tandem repeat (TR) consisting of five imperfect repeats of 25 residues each and a leucine zipper (LZ) consisting of six heptad repeats. We have examined the structure and dimerization of TR or LZ individually or the entire TR-LZ domain. Using a quenched chemical cross-linking method, we show that the TR dimerizes with moderate efficiency (Kd = 4 x 10(-6) M), whereas LZ dimerizes poorly (Kd > 2 x 10(-5) M). However, the entire TR-LZ domain dimerizes efficiently (Kd = 2 x 10(-8) M), showing a cooperative effect of the two motifs. CD analyses indicate that all three proteins contain predominantly alpha-helices. Limited proteolysis of the TR-LZ dimer indicates that the two helical motifs are linked by a small loop. Interchain disulfide bond formation indicates that both the LZ and TR helices are oriented in parallel. We propose a model for the dimer interface in the TR region consisting of discontinuous clusters of hydrophobic residues forming "leucine buttons."

Urinary assays for desmosine and hydroxylysylpyridinoline in the detection of cirrhosis

BACKGROUND/AIMS

Non-invasive markers of liver fibrosis have great potential for both the diagnosis and therapy of liver disease and cirrhosis. The aim of this study was to evaluate the potential of urinary amino acids desmosine (DES) and isodesmosine (IDES) derived from the breakdown of elastin and hydroxylysylpyridinoline (HP) and lysylpyridinoline (LP) derived from fibrillar collagen in diagnosing chronic liver disease.

METHODS

We studied 48 patients with chronic liver disease who had varying degrees of liver fibrosis, graded 0-6 using a modified Knodell score, and 20 control subjects without liver disease. Urinary DES (microg/g creatinine) and HP (nmol/mmol creatinine) were measured by an isotope dilution, high performance liquid chromatography method. For liver disease patients, aminoterminal propeptide of type III procollagen (PIIINP) and alanine aminotransferase were determined. The urine and serum markers were correlated to degree of fibrosis and inflammation on liver biopsies. Differences between groups were analyzed by ANOVA and multiple linear regression was applied to determine independence of variables. Sensitivity, specificity and receiver operating curves were derived for each marker.

RESULTS

In the 17 patients with liver fibrosis score of 5-6, mean urinary DES, IDES, HP and LP were all significantly greater than in the control group (p<0.05). Urinary DES and IDES correlated best with fibrosis score, r=0.61 for both markers. The correlation coefficient between serum PIIINP and fibrosis score was 0.47. Urinary DES and HP each had an overall diagnostic accuracy of 77% for fibrosis. Combining markers improved accuracy to over 80%. No correlation was seen between the urinary markers and inflammation scores.

CONCLUSIONS

Urinary DES and HP are potentially useful clinical markers for liver fibrosis, especially when used in combination or in association with PIIINP.

Induction of labor with use of a Foley catheter and extraamniotic corticosteroids

OBJECTIVE

Our purpose was to examine the hypothesis that corticosteroids, when administered extraamniotically, can enhance the labor process and reduce the induction-to-delivery interval.

STUDY DESIGN

A double-blind, randomized study was conducted on 98 women with a gestational age of 36 to 42 weeks, an unfavorable cervix, and medical indications for delivery, who were assigned to receive either 20 mg of dexamethasone in saline solution (study group, n = 50) or saline solution only (control group, n = 48) administered extraamniotically through an intracervical inflated Foley balloon catheter. The net effect of steroids was assessed with use of multivariant logistic regression analysis.

RESULTS

The mean time intervals between induction of labor to the active phase and between induction of labor to delivery were significantly shorter in the study group compared with those of the control group (7.8 +/- 3.1 hours vs 9.9 +/- 3.9 hours, p < 0.03, 11.9 +/- 3.0 hours vs 14.5 +/- 4.8 hours, p < 0.01, respectively). Those not receiving steroids were at a 3.2 higher risk of having a longer time interval of induction to delivery (95% confidence interval 1.1 to 9.5). The general success rate in achieving vaginal delivery was, however, similar between the groups.

CONCLUSIONS

Induction of labor with use of an intracervical Foley balloon catheter and extraamniotic corticosteroids reduces the time interval from induction of labor to delivery. This may indicate a possible role for corticosteroids in the parturition process.

New birth weight nomograms for twin gestation on the basis of accurate gestational age

OBJECTIVE

Our purpose was to establish new nomograms for the birth weight of twins on the basis of accurate methods to validate gestational age.

STUDY DESIGN

The medical records of 1632 consecutive twin gestations delivered between 1984 and 1996 were reviewed. Only pregnancies induced by ovulation induction techniques or that were measured ultrasonographically for crown-rump length during the first trimester were included. Excluded were those whose fetuses (one or both) were stillborn, or if the mother smoked, had a significant chronic illness, or was prescribed any regular medications. The study comprised 520 twin pregnancies at 28 to 41 gestational weeks at delivery.

RESULTS

The median and 10th and 90th percentile birth weight curves were calculated for the studied twins and plotted against previously reported singleton nomograms. Fetuses of twin pregnancies were found to be growth restricted in comparison with previously reported singletons throughout the third trimester. This trend became more evident after the thirty-fourth to thirty-sixth weeks.

CONCLUSIONS

We recommend these novel birth weight nomograms for clinical use in the management of twin pregnancies.

DNA binding and transcriptional activation by the Ski oncoprotein mediated by interaction with NFI

The Ski oncoprotein has been found to bind non-specifically to DNA in association with unindentified nuclear factors. In addition, Ski has been shown to activate transcription of muscle-specific and viral promoters/enhancers. The present study was undertaken to identify Ski's DNA binding and transcriptional activation partners by identifying specific DNA binding sites. We used nuclear extracts from a v-Ski-transduced mouse L-cell line and selected Ski-bound sequences from a pool of degenerate oligonucleotides with anti-Ski monoclonal antibodies. Two sequences were identified by this technique. The first (TGGC/ANNNNNT/GCCAA) is the previously identified binding site of the nuclear factor I (NFI) family of transcription factors. The second (TCCCNNGGGA) is the binding site of Olf-1/EBF. By electophoretic mobility shift assays we find that Ski is a component of one or more NFI complexes but we fail to detect Ski in Olf-1/EBF complexes. We show that Ski binds NFI proteins and activates transcription of NFI reporters, but only in the presence of NFI. We also find that homodimerization of Ski is essential for co-activation with NFI. However, the C-terminal dimerization domain of c-Ski, which is missing in v-Ski, can be substituted by the leucine zipper domain of GCN4.

In utero ultrasonographic diagnosis of an aberrant umbilical vein associated with fetal hepatic hyperechogenicity

Intra-hepatic abnormalities of the fetal umbilical venous system are poorly documented and clinically not well understood. A case of routine ultrasound examination at 23 weeks' gestation demonstrating foci of hepatic hyperechogenicity and cardiomegaly is presented. Colour Doppler detected absence of flow in the ductus venosus and markedly increased blood flow through an aberrant channel connecting the umbilical vein with the right atrium. The pregnancy was terminated and anomalous venous drainage of the umbilical vein into an enlarged hepatic vein was found, as well as hepatic congestion and focal hepatic necrosis and calcifications. Incidental findings of fetal hepatic hyperechogenicities require colour Doppler investigation of the intra- and extra-hepatic venous systems. We propose that a thrombo-embolic mechanism may be involved in the pathogenesis of these lesions.

Interleukin-10 rescues T cells from apoptotic cell death: association with an upregulation of Bcl-2

We demonstrate that interleukin-10 (IL-10) can inhibit T-cell apoptosis. T cells, within a PBMC (peripheral blood mononuclear cell) population, were stimulated via the T-cell receptor and grown in the presence of IL-2. These cells had less apoptosis when in the continuous presence of IL-10, compared with cells grown in the absence of IL-10. Conversely, when stimulated and grown in the presence of neutralizing antibody of IL-10, there was an increase in T-cell apoptosis. The in vitro rescue from apoptotic cell death of other lymphoid cells, such as germinal centre B cells, has been shown by others to involve a Bcl-2 pathway. We therefore investigated whether IL-10 might affect the Bcl-2 expression on cultured T cells. By Western blotting we demonstrated that continuous exposure of IL-10 to T cells (within a PBMC population) enhanced the expression of Bcl-2. Furthermore, T cells protected from apoptotic cell death by IL-10 were indistinguishable from viable untreated cells in their ability to proliferate to either immobilized anti-CD3 or IL-2. Thus, we have shown that continuous culture of T cells in the presence of IL-10 will inhibit T-cell apoptosis because of, at least in part, the upregulation of Bcl-2, and this is associated with a normal proliferative function.