[Impact of luteal phase support by human chorionic gonadotropin (hCG) in intrauterine inseminations]

OBJECTIVES

The objective of our study is to evaluate the impact of luteal phase support by hCG in intrauterine inseminations preceded by ovarian gonadotropin stimulation.

METHODS

A retrospective study was conducted at the CHU of Nice between March 1, 2016 and October 31, 2017. During this period, 300 intrauterine inseminations were included in data analysis. Ovarian stimulation was performed by gonadotropins and a GnRH antagonist was added, if needed. Following a modification of standard operative procedure in the department, patients who performed an intrauterine insemination from December 1, 2016 received luteal phase support with two injections of hCG 1500 IU, performed at three days of interval. Pregnancy and ovarian hyperstimulation syndrome were the primary and secondary study endpoints, respectively.

RESULTS

Out of 300 inseminations included in the analysis, 144 were performed with luteal phase support and 156 without support. No statistically significant difference in pregnancy rate was observed between these two groups (19.4% of pregnancy in the luteal phase support group and 15.38% in the group without luteal phase support, P=0.353). No ovarian hyperstimulation syndrome occurred over the course of the study.

CONCLUSION

Our study shows a slight improvement of pregnancy rate in the group subjected to luteal phase support by hCG after intrauterine insemination, but the benefit was not significant. A randomised prospective study based on a large cohort could help to assess the effect of luteal phase support during intrauterine inseminations.

Feasibility of a tapering opioids prescription program for trauma patients at high risk of chronic consumption (TOPP-trauma): protocol for a pilot randomized controlled trial

BACKGROUND

Opioid use disorder (OUD) and deaths related to the chronic use of opioids have increased significantly over the last two decades. Chronic consumption of opioids has been documented in many patients with traumatic injuries. Preliminary research findings have shown that interventions using cognitive-behavioral strategies were a promising adjunct in decreasing the burden associated with opioid consumption. Accordingly, the Tapering Opioids Prescription Program in Trauma (TOPP-Trauma) was developed.

PURPOSE

To assess the feasibility of the TOPP-Trauma intervention and its research methods; and explore the potential efficacy of TOPP-Trauma in reducing opioid consumption.

METHODS

A 2-arm pilot randomized controlled trial (RCT) will be conducted in patients presenting a high risk for chronic opioid consumption. Fifty participants at high risk for chronic consumption of opioid will receive either TOPP-Trauma or an educational pamphlet. The feasibility assessment of TOPP-Trauma will be based on the ability to provide its components as initially planned. Several parameters will be evaluated to determine the feasibility of the research methods, including the adequacy of the sampling pool, the dropout rate, and the ease of data collection. The morphine equivalent dose (MED) per day between both groups will be measured at 6 and 12 weeks. Pain intensity and pain interference with activities will also be evaluated at the same time points.

DISCUSSION

This study will provide evidence on the feasibility of a preventive program aimed at reducing chronic opioid use in high risk trauma patients. Information will also be gathered on the methods that should be used to test the efficacy of such programs.

TRIAL REGISTRATION

International Standard Randomized Controlled Trial Number (ISRCTN): 40263056. Registered 26 May 2018.

[Barriers to the use of emergency contraception in a population consulting for an abortion]

OBJECTIVES

In France, one pregnancy out of three is unplanned. Half of those pregnancies lead to abortion. However, the use of emergency contraception is far from systematic. It is therefore relevant to question the reasons and factors linked to the low rate of use of emergency contraception.

METHODS

A retrospective observational study was conducted in the orthogenic service of the University hospital Center of Nice, over a six weeks period. Patients were consulting in the context of voluntary termination of pregnancy and were subjected to a questionnaire during a semi-structured interview. The collected data were: age, degree of education, profession, size of their home town municipality, legal status, obstetrical history, contraception used at the time of unplanned pregnancy, emergency contraception background and justification for not using an emergency contraception.

RESULTS

A total of one hundred and five questionnaires were studied. The absence of emergency contraception was due to an underestimation of the risk of pregnancy in 81% of cases. Among characteristic variables of the studied population, none was related to the non-use of emergency contraception.

CONCLUSIONS

Independently of the patient profile, underestimation of the risk of pregnancy is the main cause of non-use of emergency contraception. It seems crucial to inform women with childbearing age and their families about their fertility and the basic mechanisms of fertility in order to reduce the number of unplanned pregnancies in France.

[Introduction of a bar coding pharmacy stock replenishment system in a prehospital emergency medical unit: economical impact]

OBJECTIVE

To assess economical impact after introduction of a bar coding pharmacy stock replenishment system in a prehospital emergency medical unit.

STUDY DESIGN

Observational before and after study.

METHODS

A computer system using specific software and bare-code technology was introduced in the pre hospital emergency medical unit (Smur). Overall activity and costs related to pharmacy were recorded annually during two periods: the first 2 years period before computer system introduction and the second one during the 4 years following this system installation.

RESULTS

The overall clinical activity increased by 10% between the two periods whereas pharmacy related costs continuously decreased after the start of pharmacy management computer system use. Pharmacy stock management was easier after introduction of the new stock replenishment system. The mean pharmacy related cost of one patient management was 13 Euros before and 9 Euros after the introduction of the system. The overall cost savings during the studied period was calculated to reach 134,000 Euros.

CONCLUSION

The introduction of a specific pharmacy management computer system allowed to do important costs savings in a prehospital emergency medical unit.

Pharmacokinetic (PK) and tolerance profiles of oral tegafur/uracil (UFT) given as three versus two daily intakes

12013

Background: This phase II randomized bioequivalence cross-over study compared the tolerance and PK profiles of oral UFT (tegafur-uracil) given as 3 daily intakes (tid, usual schedule) to that obtained with 2 daily intakes (bid). Methods: Twenty-one metastatic colorectal cancer patients were enrolled (16 men, 5 women ; mean age 64, extremes 42–79 ; ECOG PS ≤ 1). Tegafur-uracil (300 mg/m2/d) and leucovorin (90 mg/d) were given for 2 consecutive four-week cycles separated by one rest week. Patients were randomized for receiving 1st cycle either tid (arm A, 12 patients) or bid (arm B, 9 patients). For each schedule, PK was evaluated at steady state, over 24 h. Plasma concentrations of tegafur, uracil and fluorouracil (FU) were analyzed by HPLC. Results: Analysis of tolerance (digestive toxicity mainly, OMS grade) showed a tendency (p = 0.08) for a greater toxicity with the bid schedule (29% grade 2, 14% grade 3) relative to tid (24% grade 2 only). Although daily doses were similar, FU and uracil AUC0–24h were respectively 1.8 and 2.0-fold higher for bid as compared to tid (95% CI were 1.5–2.1 and 1.6–2.6, respectively, p < 0.0001). For tegafur, the 1.2-fold difference was of borderline significance (p = 0.057). The greater the FU AUC0–24h, the higher the toxicity intensity (p = 0.044). Analysis of systemic exposure with respect to daily time revealed that FU (p < 0.01) and uracil (p < 0.03) AUC corresponding to the morning intake were significantly higher than those corresponding to the afternoon or evening intakes, with AUC ratio as high as 1.6 for FU and 2.9 for uracil. Such a circadian influence was not observed for tegafur. Conclusions: To reach bioequivalence, bid tegafur-uracil administration will require lower doses than those given tid. The circadian variability observed for FU and uracil PK concords with that previously reported for dihydropyrimidine deshydrogenase activity.

No significant financial relationships to disclose.

Gemcitabine (G) given as a prolonged infusion in patients (pts) with advanced solid tumors: A phase I study with intra-pt dose escalation (DE) and pharmacokinetic (PK) / pharmacodynamic (PD) analysis

12029

Background: Optimizing drug delivery based on pharmacokinetic data is an important research issue. Previous studies have demonstrated a pharmacological advantage for infusions of G with a fixed dose rate to maximize cellular accumulation of G active metabolite (GTP), despite high interindividual PK variability. Methods: To develop a PK-guided G dosing schedule, we conducted an intra-pt G DE trial to determine: (1) maximum tolerated dose level (MTD) and dose-limiting toxicity (DLT), (2) plasma G and peripheral mononuclear cell GTP post-infusion levels. G was administered over 150 min on day 1, 8 and 15, q4w. The initial dose level (DL) was 1000 mg/m2, escalated by 250 mg/m2 every cycle (cy) if no limiting toxicity occurred. Results: From 09/2003, 30 pts entered the study. Pts’ characteristics: 16 men/14 women; median age 66 years (49–81); tumor type: pancreas (10 pts), lung (7 pts), others (13 pts); prior chemotherapy (15 pts). A total of 109 cy were given (median: 3 cy/pt). Tolerance: Number of pts/DL: DL1 = 7 pts, DL2 = 5 pts, DL3 = 11 pts, DL4 = 5 pts, DL5 = 2 pts. Main reasons for stopping DE were: disease progression/early death (15 pts), DLT (4 pts), investigator’s decision (8 pts). DLT were: haematological (1 pt), asthenia (2 pts) and infection (1 pt). Most common grade (gr) 1–2/3–4 toxicities (% cy) included: nausea/vomiting (38%/2%), asthenia (56%/11%), neutropenia (29%/27%) and thrombocytopenia (42%/1%). Activity: 26 pts are evaluable (radiological assessment every 3 cycles) showing 5 partial response (2 unconfirmed), 7 stabilization and 14 progression. Conclusions: The main reason for DE failure was early progression, stressing the importance of an early individual dose adjustment. PK and PK/PD correlation analyses are ongoing to confirm our hypothesis.

No significant financial relationships to disclose.

[Childhood cancer incidence and survival rates in the Rhône-Alpes regional paediatric registry 1987-1999]

Cancer is rare in children, and pediatric malignancies represent only 1% of all cancers.

OBJECTIVES

The cure rate is high and increasing, and ongoing data collection is therefore warranted.

MATERIALS AND METHODS

Here we report the incidence and survival rates of childhood cancers between 1987 and 1999 in the Rhône-Alpes region of France.

RESULTS

A total of 1945 cases were recorded during the study period, with an average of 149.6 new cases per year. The approximate incidence rate was 134.1/10(6) per year and the age-standardized incidence rate was 139.2/10(6) per year. The histological distribution and 5-year survival rates were respectively 30.2 and 73% for leukemia, 12.3 and 91.6% for lymphoma, 24.7 and 60.1% for CNS tumors, 9.1 and 71.1% for neuroblastoma, 2.5 and 94.1% for retinoblastoma, 5.8% and 89.9% for renal tumors, 1 and 75% for liver tumors, 6.1 and 60.9% for bone tumors, 4.1 and 58.6% for soft-tissue tumors, 1.1 and 71% for germ cell tumors, and 2.4 and 85.1% for carcinomas.

CONCLUSION

The overall survival rate was 75%. Long-term treatment complications warrant further studies of children who survive into adulthood.

[Gastric trichobezoar in an adolescent presenting with anemia: ultrasound and MRI findings]

Trichobezoars are rare and composed of ingested hair or fibers. Diagnosis is usually made by plain radiographs and barium meal. The usefulness of computed tomography has been reported in the preoperative period. In the pediatric population the authors propose, based on a recent case report, a non invasive and non irradiating protocol using sonography and T1W and T2W MR imaging.

Rapid upregulation of telomerase activity in human leukemia HL-60 cells treated with clinical doses of the DNA-damaging drug etoposide

The enzyme telomerase is implicated in cellular resistance to apoptosis, but the mechanism for this resistance remains to be elucidated. The ability of telomerase to synthesize new DNA at telomeres suggests that this enzyme might function in the repair of double-stranded DNA breaks. To distinguish the effects of double-stranded DNA break damage and apoptosis on human telomerase activity, we treated the HL-60 human hematopoietic cancer cell line with clinical doses of the chemotherapeutic drug etoposide (0.5 to 5 microM), which allowed us to distinguish between events associated with DNA damage-induced cell cycle arrest, and events associated with apoptosis. Large (three- to seven-fold) upregulation of telomerase activity occurred soon after etoposide treatment (3 h) in S/G2/M-arresting populations; this upregulation was abolished at onset of apoptotic cell death. No upregulation of telomerase activity was observed in cells treated with a larger dose of etoposide (5 microM) that caused cells to undergo rapid apoptosis without intervening cell cycle arrests. These observations are consistent with a possible role for telomerase upregulation during the DNA damage response.

Inherited disorders of IL-12- and IFNgamma-mediated immunity: a molecular genetics update

In the last 6 years, considerable advances have been made in the molecular analysis of a rare clinical syndrome: Mendelian susceptibility to mycobacterial disease (MSMD). Infection with poorly virulent environmental non-tuberculous mycobacteria (NTM) or vaccination with bacillus Calmette-Guerin (BCG) may cause disseminating and even fatal disease in individuals suffering from this syndrome. Mutations in five genes (IFNGR1, IFNGR2, STAT1, IL12B and IL12RB1) have been shown to be responsible for MSMD and further allelic heterogeneity accounts for the existence of nine distinct inherited disorders. All of these disorders are caused by impaired IFNgamma-mediated immunity. These results have important medical and biological implications. In this report, we update the disease-causing mutations reported in the literature.

Mycobacterial diseases in primary immunodeficiencies

Primary immunodeficiency diseases comprise over 100 conditions, each associated with a variety of viral, bacterial, fungal and protozoan infections. M. tuberculosis and less virulent mycobacteria, such as bacille Calmette-Guérin vaccines and environmental non-tuberculous mycobacteria, may cause severe disease in patients with primary immunodeficiency diseases. However, no previous review has dealt with the issue of which primary immunodeficiency diseases predispose affected individuals to mycobacterial disease. This information is very useful, not only increasing our understanding of human immunity to mycobacteria, but also for the diagnostic investigation of patients with mycobacteriosis. We review here the medical literature on cases of mycobacterial disease in patients with primary immunodeficiency diseases.

[T-cell-depleted HLA non-identical bone marrow transplantation in the child: prevention of graft-versus-host reaction by administration of donor T lymphocytes alloreactive against the recipient]

The success of HSCT from HLA partially disparate donors depends on the development of new strategies able to efficiently prevent GVHD and to protect patients from infections and relapse. Using an immunotoxin (IT) directed against the alpha-chain (p55) of the human IL-2r (RFT5-SMPT-dgA), we have previously shown that it is possible to kill mature T cells activated towards a specific HLA complex by a one-way MLR. We designed a clinical trial assessing the effect of infusing increasing doses of T lymphocytes in the setting of children recipients of non HLA genetically identical HSCT. Thirteen patients have been enrolled from September 1998 to April 2000 and fourteen HSCT have been realized in 13 patients (pts). Donors were MUD in 3 cases and familial HLA partially disparate in the remaining cases. Allodepleted donor T cells were injected between day +14 and day +30 provided that ATG was undetectable in the serum and blood PMN counts was > 500/microliter. The mean age of these patients was 17 months (range 1 to 42). Diagnosis included immune deficient and malignant hemopathies. Three patients received 1 x 10(5) allodepleted T cell/kg, 7 patients received 4 x 10(5)/kg and 4 patients received 6 x 10(5)/kg allodepleted T cells. Full inhibition of MLR was achieved in 12 out of 14 cases. In two cases, a residual T cell reactivity to the recipient was observed (4 to 5%) and patients developed grade II aGVHD. aGVHD occurred in 4 out of 11 grafted patients (all grade II). No chronic GVHD has developed, so far. Three patients died from severe VOD or PHT at day +34, day 51 and day +166, while one infected patient by VZV, CMV and EBV before HSCT died 6 months after transplantation from meningoencephalitis and another patient died from relapse at day +291. The patient for which there was no engraftment died at day +48 from staphylococcus infection. Overall survival is 54%, with a median follow up of 8 months; the mean time to reach a blood lymphocyte count > 500 was 41 days, to reach a CD3 count > 300 microliters 63 days (20-111), CD4 > 200 microliters 97 days and positive mitogen-induced proliferation 90 days. In three patients, a tetanus-toxoid positive proliferation was detected before immunization. From this intermediate analysis, we conclude that 1) specific allodepletion is an effective approach to prevent aGVHD in a haploincompatible setting, 2) data on immunological reconstitution suggest that infused T cells do survive and expand. A higher number of patients must be enrolled to determine the optimal number of T cells to infuse.

Role of clathrin in the regulated secretory pathway of pancreaticβ-cells

The role of clathrin in the sorting of proinsulin to secretory granules,the formation of immature granules and their subsequent maturation is not known. To this end, primary rat pancreatic β-cells were infected with a recombinant adenovirus co-expressing the Hub fragment, a dominant-negative peptide of the clathrin heavy chain and enhanced green fluorescent protein(EGFP as a marker of infected cells). A population of cells expressing the highest levels of EGFP (and thus Hub) was obtained using a fluorescence-activated cell sorter (FACS). Control cells were infected with an adenovirus expressing EGFP alone. By immunofluorescence, control cells showed intense staining for both clathrin light chain and proinsulin in a perinuclear region. In cells expressing high levels of Hub, the clathrin light-chain signal was faint and diffuse in keeping with its displacement from membranes. There was, however, no detectable effect of Hub expression on proinsulin staining or disposition within the cell. Proinsulin sorting and conversion,and the fate (release and/or degradation) of insulin and C-peptide, was studied by pulse-chase and quantitative reverse phase HPLC. In both Hub-expressing and control cells, &gt;99% of all newly synthesized proinsulin was sorted to the regulated pathway and there was no effect of Hub on proinsulin conversion to insulin. In presence of Hub there was, however, a significant increase in the percentage of C-peptide truncated to des-(27-31)-C-peptide at early times of chase as well as more extensive degradation of C-peptide thereafter. It is concluded that clathrin is not implicated in the sorting or processing of proinsulin or in regulated exocytosis of secretory granules. These results confirm a role for clathrin in the removal of proteases from maturing granules, thus explaining the increased truncation and degradation of C-peptide in cells expressing Hub.

Impairment of mycobacterial but not viral immunity by a germline human STAT1 mutation

Interferons (IFN) alpha/beta and gamma induce the formation of two transcriptional activators: gamma-activating factor (GAF) and interferon-stimulated gamma factor 3 (ISGF3). We report a natural heterozygous germline STAT1 mutation associated with susceptibility to mycobacterial but not viral disease. This mutation causes a loss of GAF and ISGF3 activation but is dominant for one cellular phenotype and recessive for the other. It impairs the nuclear accumulation of GAF but not of ISGF3 in heterozygous cells stimulated by IFNs. Thus, the antimycobacterial, but not the antiviral, effects of human IFNs are principally mediated by GAF.

Recurrent Mycobacterium avium osteomyelitis associated with a novel dominant interferon gamma receptor mutation

Mycobacterium avium causes infections in immunocompromised individuals. Recurrent infection with this organism has been associated with a deletion at the 818 residue of the interferon-gamma receptor (IFN-gammaR). This mutation produces a truncated receptor without an intracytoplasmic tail, resulting in diminished signaling. We describe a substitution at the 832 residue of the IFN-gammaR causing a similar truncated receptor in a 7-year-old girl with recurrent M avium osteomyelitis.

High levels of interferon gamma in the plasma of children with complete interferon gamma receptor deficiency

We have found that children with complete interferon gamma (IFNgamma) receptor deficiency, unlike patients with other genetic defects predisposing them to mycobacterial diseases, have very high levels of IFNgamma in their plasma. This unexpected observation provides a simple and accurate diagnostic method for complete IFNgamma receptor deficiency in children with clinical disease caused by bacille Calmette-Guérin vaccines or environmental nontuberculous mycobacteria.

Polypyrimidine track-binding protein binding downstream of caspase-2 alternative exon 9 represses its inclusion

We have been using the caspase-2 pre-mRNA as a model system to study the importance of alternative splicing in the regulation of programmed cell death. Inclusion or skipping of a cassette-type exon in the 3' portion of this pre-mRNA leads to the production of isoforms with antagonistic activity in apoptosis. We previously identified a negative regulatory element (In100) located in the intron downstream of alternative exon 9. The upstream portion of this element harbors a decoy 3' acceptor site that engages in nonproductive commitment complex interactions with the 5' splice site of exon 9. This in turn confers a competitive advantage to the exon-skipping splicing pattern. Further characterization of the In100 element reveals a second, functionally distinct, domain located downstream from the decoy 3' acceptor site. This downstream domain harbors several polypyrimidine track-binding protein (PTB)-binding sites. We show that PTB binding to these sites correlates with the negative effect on exon 9 inclusion. Finally, we show that both domains of the In100 element can function independently to repress exon 9 inclusion, although PTB binding in the vicinity of the decoy 3' splice site can modulate its activity. Our results thus reveal a complex composite element that regulates caspase-2 exon 9 alternative splicing through a novel mechanism.

The N-terminal leucine-rich regions in Slit are sufficient to repel olfactory bulb axons and subventricular zone neurons

The Slit proteins are a new family of secreted guidance cues involved in axon guidance and neuronal migration. Each mammalian Slit protein contains >1400 amino acid residues, with four leucine-rich regions (LRRs), nine epidermal growth factor repeats, a laminin G domain, and a C-terminal cysteine-rich domain. A receptor for Slit is the transmembrane protein Roundabout (Robo), whose extracellular part contains five Ig domains and three fibronectin type III repeats. We report here that the LRRs in Slit are sufficient for binding to the Ig domains of Robo. Mutant forms of Slit containing only the LRRs function as chemorepellents for axons projecting from the olfactory bulb both in vitro and in the telencephalon. The LRRs can repel neurons migrating from the anterior subventricular zone (SVZa) to the olfactory bulb in brain slices isolated from neonatal rodents. However, the LRRs do not show repulsive effects on the SVZa neurons migrating in collagen gels. Our results indicate that the same LRRs are sufficient for guiding both axon projection and neuronal migration and suggest that the other regions in the Slit proteins may be involved in regulating the diffusion and distribution of the Slit proteins. The fact that the same domains are involved in guiding axon projection and neuronal migration further strengthens the idea of a conserved guidance mechanism for these important processes.

Caspase-2 pre-mRNA alternative splicing: Identification of an intronic element containing a decoy 3' acceptor site

We have established a model system using the caspase-2 pre-mRNA and initiated a study on the role of alternative splicing in regulation of programmed cell death. A caspase-2 minigene construct has been made that can be alternatively spliced in transfected cells and in nuclear extracts. Using this system, we have identified a 100-nt region in downstream intron 9 that inhibits the inclusion of the 61-bp alternative exon. This element (In100) can facilitate exon skipping in the context of competing 3' or 5' splice sites, but not in single-intron splicing units. The In100 element is also active in certain heterologous pre-mRNAs, although in a highly context-dependent manner. Interestingly, we found that In100 contains a sequence that highly resembles a bona fide 3' splice site. We provide evidence that this sequence acts as a "decoy" acceptor site that engages in U2 snRNP-dependent but nonproductive splicing complexes with the 5' splice site of exon 9, hence conferring competitive advantage to the exon-skipping splicing event (E8-E10). These results reveal a mechanism of action for a negative intronic regulatory element and uncover a role for U2 snRNP in the regulation of alternative splicing.

Human interferon-gamma-mediated immunity is a genetically controlled continuous trait that determines the outcome of mycobacterial invasion

Individuals with inherited disorders of interferon gamma (IFN-gamma)-mediated immunity appear to be specifically vulnerable to mycobacterial infections. The severity of clinical features of affected individuals differs between cases. Some patients die of mycobacterial infection in early childhood, whereas others have long asymptomatic periods in childhood and as adults. This rare syndrome also shows high allelic and non-allelic genetic heterogeneity. Mutations in IL12B, encoding the interleukin (IL)-12 p40 subunit, and in IL12RB1, encoding the beta1 chain of the IL-12 receptor, result in impaired IFN-gamma production. Mutations in IFNGR1 and IFNGR2, encoding the two IFN-gamma receptor chains, and mutations in STAT1, encoding an essential signaling component, result in impaired cellular responses to IFN gamma. Different types of mutation define two types of complete and two types of partial IFNgammaR1 deficiency. Complete and partial IFNgammaR2 deficiency have also been described. We herein compare the genotypes, cellular phenotypes, and clinical phenotypes of healthy individuals and patients with the seven known genetic disorders impairing cellular responses to IFN-gamma. Patients with defective IFN-gamma production were not considered in this study. The mutations and clinical features of patients with IFNgammaR1, IFNgammaR2, and STAT-1 deficiency are reviewed. Selected cell lines from each of the eight groups were tested for their response to IFN-gamma. We find that individuals may be classified into four broad groups based on genotype, cellular phenotype, and clinical phenotype (normal individuals and patients with mild, intermediate, or severe disease). This correlation suggests that IFN-gamma-mediated cell activation is a genetically controlled quantitative trait and that it determines the outcome of mycobacterial invasion in man.

Synthesis and in vitro opioid activity profiles of DALDA analogues

The tetrapeptide DALDA (H-Tyr-D-Arg-Phe-Lys-NH2) is a polar and selective mu agonist showing poor penetration of the placental and blood-brain barriers. In an effort to enhance the potency of DALDA, analogues containing 2',6'-dimethyltyrosine (Dmt), N,2',6'-trimethyltyrosine (Tmt), 2'-methyltyrosine (Mmt) or 2'-hydroxy,6'-methyltyrosine (Hmt) in place of Tyr1, or Orn or alpha,gamma-diaminobutyric acid (A2bu) in place of Lys4, were synthesized. All compounds displayed high mu receptor selectivity in the rat and guinea pig brain membrane binding assays and most of them were more potent mu agonists than DALDA in the mu receptor-representative guinea pig ileum assay, with [Dmt1]DALDA showing the highest potency. Because of its extraordinary mu agonist potency, high mu selectivity, polar character (charge of 3 + ) and metabolic stability, [Dmt1]DALDA has potential for use in obstetrical or peripheral analgesia.

Mutations in RAB27A cause Griscelli syndrome associated with haemophagocytic syndrome

Griscelli syndrome (GS, MIM 214450), a rare, autosomal recessive disorder, results in pigmentary dilution of the skin and the hair, the presence of large clumps of pigment in hair shafts and an accumulation of melanosomes in melanocytes. Most patients also develop an uncontrolled T-lymphocyte and macrophage activation syndrome (known as haemophagocytic syndrome, HS), leading to death in the absence of bone-marrow transplantation. In contrast, early in life some GS patients show a severe neurological impairment without apparent immune abnormalities. We previously mapped the GS locus to chromosome 15q21 and found a mutation in a gene (MYO5A) encoding a molecular motor in two patients. Further linkage analysis suggested a second gene associated with GS was in the same chromosomal region. Homozygosity mapping in additional families narrowed the candidate region to a 3.1-cM interval between D15S1003 and D15S962. We detected mutations in RAB27A, which lies within this interval, in 16 patients with GS. Unlike MYO5A, the GTP-binding protein RAB27A appears to be involved in the control of the immune system, as all patients with RAB27A mutations, but none with the MYO5A mutation, developed HS. In addition, RAB27A-deficient T cells exhibited reduced cytotoxicity and cytolytic granule exocytosis, whereas MYO5A-defective T cells did not. RAB27A appears to be a key effector of cytotoxic granule exocytosis, a pathway essential for immune homeostasis.

Heterogeneous nuclear ribonucleoprotein A1 and UP1 protect mammalian telomeric repeats and modulate telomere replication in vitro

The heterogeneous nuclear ribonucleoprotein A1 protein and a shortened derivative (UP1) promote telomere elongation in mammalian cells. To gain insights into the function of A1/UP1 in telomere biogenesis, we have investigated the binding properties of recombinant A1/UP1 and derivatives to single-stranded DNA oligonucleotides. Our results indicate that UP1 prefers to bind to DNA carrying single-stranded telomeric extensions at the 3' terminus. The RNA recognition motif 1 is sufficient for strong and specific binding to oligomers carrying vertebrate telomeric repeats. We find that the binding of A1/UP1 protects telomeric sequences against degradation by endo- and exonucleases. Moreover, A1/UP1 binding prevents extension by telomerase and terminal deoxynucleotidyltransferase and inhibits rNTP-dependent DNA synthesis in vitro. These observations are consistent with the hypothesis that A1/UP1 is a telomere end-binding protein that plays a role in the maintenance of long 3' overhangs.

In a novel form of IFN-gamma receptor 1 deficiency, cell surface receptors fail to bind IFN-gamma

Complete IFN-gamma receptor ligand-binding chain (IFNgammaR1) deficiency is a life-threatening autosomal recessive immune disorder. Affected children invariably die of mycobacterial infection, unless bone marrow transplantation is undertaken. Pathogenic IFNGR1 mutations identified to date include nonsense and splice mutations and frameshift deletions and insertions. All result in a premature stop codon upstream from the segment encoding the transmembrane domain, precluding cell surface expression of the receptors. We report herein two sporadic and two familial cases of a novel form of complete IFNgammaR1 deficiency in which normal numbers of receptors are detected at the cell surface. Two in-frame deletions and two missense IFNGR1 mutations were identified in the segment encoding the extracellular ligand-binding domain of the receptor. Eight independent IFNgammaR1-specific mAb's, including seven blocking antibodies, gave recognition patterns that differed between patients, suggesting that different epitopes were altered by the mutations. No specific binding of (125)I-IFN-gamma to cells was observed in any patient, however, and the cells failed to respond to IFN-gamma. The mutations therefore cause complete IFNgammaR1 deficiency by disrupting the IFN-gamma-binding site without affecting surface expression. The detection of surface IFNgammaR1 molecules by specific antibodies, including blocking antibodies, does not exclude a diagnosis of complete IFNgammaR1 deficiency.

Quantitation and characterization of phospholipids in pharmaceutical formulations by liquid chromatography-mass spectrometry

A simple and fast method for phospholipid analysis was developed using high-performance liquid chromatography-mass spectrometry with an atmospheric pressure ionization interface. Separation of the phospholipid molecular species was achieved using a linear gradient of a mixture of chloroform-10 mM ammonium acetate-methanol (30:5:65) on a silica column. Optimization of the mass spectrometer conditions has allowed the method to separate and detect the phospholipids mainly as protonated molecular species. In comparison to existing LC-MS methods, improvement in the total analysis time and sensitivity were achieved. Separation of all major phospholipid molecular classes was achieved in less than 6 min. Marked improvement was observed in the linearity of the response of the phospholipids studied providing a linear response over three orders of magnitude. Data supporting the validation of this method for the characterization of major phospholipids molecular species are also presented.

Partial interferon-gamma receptor signaling chain deficiency in a patient with bacille Calmette-Guérin and Mycobacterium abscessus infection

Complete deficiency of either of the two human interferon (IFN)-gamma receptor components, the ligand-binding IFN-gammaR1 chain and the signaling IFN-gammaR2 chain, is invariably associated with early-onset infection caused by bacille Calmette-Guérin vaccines and/or environmental nontuberculous mycobacteria, poor granuloma formation, and a fatal outcome in childhood. Partial IFN-gammaR1 deficiency is associated with a milder histopathologic and clinical phenotype. Cells from a 20-year-old healthy person with a history of curable infections due to bacille Calmette-Guérin and Mycobacterium abscessus and mature granulomas in childhood were investigated. There was a homozygous nucleotide substitution in IFNGR2, causing an amino acid substitution in the extracellular region of the encoded receptor. Cell surface IFN-gammaR2 were detected by flow cytometry. Cellular responses to IFN-gamma were impaired but not abolished. Transfection with the wild-type IFNGR2 gene restored full responsiveness to IFN-gamma. This is the first demonstration of partial IFN-gammaR2 deficiency in humans.

Directional guidance of neuronal migration in the olfactory system by the protein Slit

Although cell migration is crucial for neural development, molecular mechanisms guiding neuronal migration have remained unclear. Here we report that the secreted protein Slit repels neuronal precursors migrating from the anterior subventricular zone in the telencephalon to the olfactory bulb. Our results provide a direct demonstration of a molecular cue whose concentration gradient guides the direction of migrating neurons. They also support a common guidance mechanism for axon projection and neuronal migration and suggest that Slit may provide a molecular tool with potential therapeutic applications in controlling and directing cell migration.

IL-12 and IFN-gamma in host defense against mycobacteria and salmonella in mice and men

The development of gene-knockout mice and the identification of gene-deficient humans have improved our understanding of the role of IL-12 and IFN-gamma in host defense. Comparison of experimental and natural infections has shown that animals and humans genetically deficient in immunity mediated by IL-12 or IFN-gamma are highly susceptible to mycobacteria and salmonella. Impaired secretion of, or response to, IFN-gamma is the common pathogenic mechanism that accounts for impaired granuloma formation and uncontrolled growth of bacteria within macrophages. The axis formed between IL-12 and IFN-gamma is essential for protective immunity against mycobacteria and salmonella in mice and men.

A human IFNGR1 small deletion hotspot associated with dominant susceptibility to mycobacterial infection

The immunogenetic basis of severe infections caused by bacille Calmette-Guérin vaccine and environmental mycobacteria in humans remains largely unknown. We describe 18 patients from several generations of 12 unrelated families who were heterozygous for 1 to 5 overlapping IFNGR1 frameshift small deletions and a wild-type IFNGR1 allele. There were 12 independent mutation events at a single mutation site, defining a small deletion hotspot. Neighbouring sequence analysis favours a small deletion model of slipped mispairing events during replication. The mutant alleles encode cell-surface IFNgamma receptors that lack the intra-cytoplasmic domain, which, through a combination of impaired recycling, abrogated signalling and normal binding to IFNgamma exert a dominant-negative effect. We thus report a hotspot for human IFNGR1 small deletions that confer dominant susceptibility to infections caused by poorly virulent mycobacteria.

Vertebrate slit, a secreted ligand for the transmembrane protein roundabout, is a repellent for olfactory bulb axons

The olfactory bulb plays a central role in olfactory information processing through its connections with both peripheral and cortical structures. Axons projecting from the olfactory bulb to the telencephalon are guided by a repulsive activity in the septum. The molecular nature of the repellent is not known. We report here the isolation of vertebrate homologs of the Drosophila slit gene and show that Slit protein binds to the transmembrane protein Roundabout (Robo). Slit is expressed in the septum whereas Robo is expressed in the olfactory bulb. Functionally, Slit acts as a chemorepellent for olfactory bulb axons. These results establish a ligand-receptor relationship between two molecules important for neural development, suggest a role for Slit in olfactory bulb axon guidance, and reveal the existence of a new family of axon guidance molecules.

Telomere elongation by hnRNP A1 and a derivative that interacts with telomeric repeats and telomerase

Telomeric DNA of mammalian chromosomes consists of several kilobase-pairs of tandemly repeated sequences with a terminal 3' overhang in single-stranded form. Maintaining the integrity of these repeats is essential for cell survival; telomere attrition is associated with chromosome instability and cell senescence, whereas stabilization of telomere length correlates with the immortalization of somatic cells. Telomere elongation is carried out by telomerase, an RNA-dependent DNA polymerase which adds single-stranded TAGGGT repeats to the 3' ends of chromosomes. While proteins that associate with single-stranded telomeric repeats can influence tract lengths in yeast, equivalent factors have not yet been identified in vertebrates. Here, it is shown that the heterogeneous nuclear ribonucleoprotein A1 participates in telomere biogenesis. A mouse cell line deficient in A1 expression harbours telomeres that are shorter than those of a related cell line expressing normal levels of A1. Restoring A1 expression in A1-deficient cells increases telomere length. Telomere elongation is also observed upon introduction of exogenous UP1, the amino-terminal fragment of A1. While both A1 and UP1 bind to vertebrate single-stranded telomeric repeats directly and with specificity in vitro, only UP1 can recover telomerase activity from a cell lysate. These findings establish A1/UP1 as the first single-stranded DNA binding protein involved in mammalian telomere biogenesis and suggest possible mechanisms by which UP1 may modulate telomere length.

Human recombinant IL-4 decreases the emergence of non-specific cytolytic cells and favours the appearance of memory cells (CD4+CD45RO+) in the IL-2-driven development of cytotoxic T lymphocytes against autologous ovarian tumour cells

As IL-4 and IL-6 have also been reported to promote the development of T lymphocytes such as IL-2, we investigated their role in the development of specific cytotoxic T lymphocytes (CTL) against autologous ovarian tumours in mixed lymphocyte tumour cultures (MLTC). Peripheral blood lymphocytes (PBL) from five ovarian carcinoma (OC) patients were incubated with autologous OC cells at a PBL:OC cell ratio of 20:1 in IL-2 alone (50 U/ml for the first week and 200 U/ml thereafter) or with IL-4 (100 U/ml) and/or IL-6 (5 U/ml). Neither IL-4 nor IL-6 improved lymphocyte proliferation consistently. In contrast, IL-4 reduced significantly the development of LAK activity as assayed against Daudi cell line, and decreased modestly the emergence of natural killer (NK) activity as assayed against K562. This property was not shared by IL-6. The prevention of the development of non-specific cytolytic activity (LAK and NK activities) was much stronger when the MLTC was started with IL-4 in the absence of IL-2 during the first week in culture. A concomitant drop in NKH-1 expression (CD56) was observed. By inhibiting the emergence of non-specific cytotoxicity, IL-4 provided better evidence of the specific cytolytic activity directed at ovarian cells. In parallel, a significant increase in the generation of memory cells (CD4+CD45RO+) was observed with IL-4. In conclusion, in this model, IL-4 added before IL-2 decreases significantly the emergence of non-specific cytotoxic cells, and promotes the generation of memory cells. These properties may be of interest in the design of strategies aimed at obtaining tumour-specific cells for investigational and immunotherapeutic purposes.