An enantioselective three-step synthesis of the GABA uptake inhibitor (S)-(+)-homo-β-proline was developed. The basis for the synthesis was the enantioselective CuI-catalyzed cyclopropanation of ...N-Boc-pyrrole, a substrate that persistently has proved to be challenging in such transformations. The cyclopropanation can be performed on a 150 mmol scale, and the two subsequent steps (i.e., hydrogenation and in situ cyclopropane-opening/double-deprotection) toward the target molecule proceed smoothly in quantitative yield without loss of enantiopurity.
Interplay between proteins, nucleic acids, carbohydrates and/or lipids is involved in almost every process in life on earth. As a consequence, a wide range of diseases results from abnormal ...interactions of such biomolecules. The main motivation of foldamer science is the development of scaffolds that are capable of adopting defined structures, mimicking parts of biological protagonists in their function. Among the most fundamental interactions in living beings are those between proteins, the so called protein–protein interactions (PPIs). Therefore, peptidic foldamers bear the promise to be an important tool for the inhibition of PPIs, as they are structurally most similar to the original proteins. The great number of possible permutations given by the combination of proteinogenic α-amino acid residues along with β-amino acids opens the door for a larger pool of accessible structures with potential applications. Despite the increasing amount of new secondary structure motifs, only few examples for tertiary and quaternary structure design, as well as inhibition of PPIs, have been realized so far. In this review, we summarize the current knowledge and recent progress made in the field of α/β-peptide foldamers beginning from secondary structure design up to highly sophisticated biological applications, such as protein surface recognition and inhibition of HIV cell entry.
The development of constrained peptides for inhibition of protein-protein interactions is an emerging strategy in chemical biology and drug discovery. This manuscript introduces a versatile, rapid ...and reversible approach to constrain peptides in a bioactive helical conformation using BID and RNase S peptides as models. Dibromomaleimide is used to constrain BID and RNase S peptide sequence variants bearing cysteine (Cys) or homocysteine (
Cys) amino acids spaced at
and
+ 4 positions by double substitution. The constraint can be readily removed by displacement of the maleimide using excess thiol. This new constraining methodology results in enhanced α-helical conformation (BID and RNase S peptide) as demonstrated by circular dichroism and molecular dynamics simulations, resistance to proteolysis (BID) as demonstrated by trypsin proteolysis experiments and retained or enhanced potency of inhibition for Bcl-2 family protein-protein interactions (BID), or greater capability to restore the hydrolytic activity of the RNAse S protein (RNase S peptide). Finally, use of a dibromomaleimide functionalized with an alkyne permits further divergent functionalization through alkyne-azide cycloaddition chemistry on the constrained peptide with fluorescein, oligoethylene glycol or biotin groups to facilitate biophysical and cellular analyses. Hence this methodology may extend the scope and accessibility of peptide stapling.
Purpose
Psychosocial health (PH) and quality of life (QoL) are important health outcomes. We compared PH and QoL of adolescents conceived with intrazytoplasmatic sperm injection (ICSI) and of ...naturally conceived controls. The impact of disclosure of ICSI-conception on QoL and PH was quantified.
Methods
The cross-sectional sample consisted of 545 ICSI-conceived adolescents and 427 unmatched singleton controls aged 14–18 years. Adolescents reported PH with the ‘Strengths and Difficulties Questionnaire’ (low values indicating high PH), and QoL with the KINDL questionnaire (high values indicating high QoL). Because of clustering of multiples within families, adjusted linear regressions with generalized estimating equations were used to compare ICSI- and naturally conceived adolescents. Missing values were treated by multiple imputation. Minimal importance was defined as half a standard deviation.
Results
Both ICSI and control adolescents had high PH (low mean ‘total difficulties’ score: 9 of 40) and high QoL (mean ‘total KINDL’ score: 75 of 100). Differences were generally in favour of the ICSI group. Significant differences occurred for ‘impact of behavioural problems’ (
p
= 0.033), the ‘total KINDL’ score (
p
= 0.021) and the dimensions ‘physical wellbeing’ (
p
= 0.031) and ‘school’ (
p
= 0.005), but all differences were far below minimal importance. About 80% of ICSI adolescents were informed about their mode of conception. PH and QoL were slightly higher in informed adolescents; behavioural difficulties (‘total behavioural problems’ and ‘conduct problems’) were significantly lower (
p
= 0.013 and
p
= 0.003), behavioural strengths (‘prosocial behaviour’) and ‘physical QoL’ significantly higher (
p
= 0.004 and
p
= 0.018), but differences remained clearly below minimal importance.
Conclusions
Our results are reassuring for parents using ICSI and their children. Speaking openly about an ICSI conception in the family may be beneficial.
Nonsyndromic cleft palate only (nsCPO) is a facial malformation that has a livebirth prevalence of 1 in 2,500. Research suggests that the etiology of nsCPO is multifactorial, with a clear genetic ...component. To date, genome-wide association studies have identified only 1 conclusive common variant for nsCPO, that is, a missense variant in the gene grainyhead-like-3 (GRHL3). Thus, the underlying genetic causes of nsCPO remain largely unknown. The present study aimed at identifying rare variants that might contribute to nsCPO risk, via whole-exome sequencing (WES), in multiply affected Central European nsCPO pedigrees. WES was performed in 2 affected first-degree relatives from each family. Variants shared between both individuals were analyzed for their potential deleterious nature and a low frequency in the general population. Genes carrying promising variants were annotated for 1) reported associations with facial development, 2) multiple occurrence of variants, and 3) expression in mouse embryonic palatal shelves. This strategy resulted in the identification of a set of 26 candidate genes that were resequenced in 132 independent nsCPO cases and 623 independent controls of 2 different ethnicities, using molecular inversion probes. No rare loss-of-function mutation was identified in either WES or resequencing step. However, we identified 2 or more missense variants predicted to be deleterious in each of 3 genes (ACACB, PTPRS, MIB1) in individuals from independent families. In addition, the analyses identified a novel variant in GRHL3 in 1 patient and a variant in CREBBP in 2 siblings. Both genes underlie different syndromic forms of CPO. A plausible hypothesis is that the apparently nonsyndromic clefts in these 3 patients might represent hypomorphic forms of the respective syndromes. In summary, the present study identified rare variants that might contribute to nsCPO risk and suggests candidate genes for further investigation.
The combination of single-cell transcriptomics with mitochondrial DNA variant detection can be used to establish lineage relationships in primary human cells, but current methods are not scalable to ...interrogate complex tissues. Here, we combine common 3' single-cell RNA-sequencing protocols with mitochondrial transcriptome enrichment to increase coverage by more than 50-fold, enabling high-confidence mutation detection. The method successfully identifies skewed immune-cell expansions in primary human clonal hematopoiesis.
Although transvaginal ultrasound-guided oocyte retrievals (OR) are performed routinely worldwide, there is very little systematic data about its complications. METHODS: We performed a prospective ...cohort study following the perioperative and post-operative complications of over 1058 ORs. Additionally, we assessed the pain experienced during the OR. RESULTS: A total of 1166 OR were performed during the study period, of which 1058 (90.7%) ORs were included prospectively. Incomplete data meant that the remaining 9.3% were excluded. No complications were caused by sedation or general anaesthesia. Vaginal bleeding was observed in 2.8% of procedures, without any cases of intra-abdominal bleeding. An injury of pelvic structures (a ureteral lesion) occurred in one case. No case of pelvic infection, but one case of unexplained fever, was observed. A severe ovarian hyperstimulation syndrome (OHSS) occurred in 2.7% of cases. Although most patients tolerated the OR well, 3% of patients experienced severe to very severe pain after the OR and 2% of patients were still suffering from severe pain 2 days after the procedure. The pain level increased with the number of oocytes retrieved. About 0.7% of patients required hospitalization for pain treatment. CONCLUSIONS: Patients can be reassured that overall OR is a safe procedure. However, patients have to be counselled about the minor risks of the OR. The literature on complications is reviewed in the article.
Abstract
STUDY QUESTION
Are there any differences in the pubertal development and reproductive hormone status during adolescence between singletons following ICSI therapy or spontaneous conception ...(SC)?
SUMMARY ANSWER
Pubertal development and reproductive hormone levels are largely similar between ICSI and SC adolescents, except for a tendency towards lower inhibin B levels as well as significantly higher estradiol levels and a lower testosterone-to-estradiol-ratio in male adolescents.
WHAT IS KNOWN ALREADY
Previous data are scarce and partly inconclusive regarding pubertal development in female ICSI adolescents as well as demonstrating a tendency towards lower inhibin B serum levels in male ICSI offspring.
STUDY DESIGN, SIZE, DURATION
Prospective controlled study including 274 singleton ICSI-conceived adolescents (141 girls, 133 boys) followed up for the third time, and 273 SC controls (142 girls, 131 boys) from seven German registration offices (Aachen, Eichstätt, Erfurt, Lübeck, Hamburg, Heidelberg and Schwerin).
PARTICIPANTS/MATERIALS, SETTING, METHODS
Pubertal development assessed by Tanner staging (breast, genital and pubic hair development), age at menarche and reproductive hormone levels were analyzed in ICSI and SC adolescents at the mean age of 16.5 years. Differences were analyzed by multinomial regression (Tanner stages) or t test and linear regression for hormonal assessments.
MAIN RESULTS AND THE ROLE OF CHANCE
Both female and male ICSI and SC adolescents showed adequate pubertal maturation according to their age, and the mean age at menarche (at 12.7 versus 12.8 years) was similar. Tanner stages as well did not display any relevant or significant differences between the groups. Reproductive hormone levels in female adolescents not using hormonal contraception were largely similar before and after adjustment for several factors such as preterm birth, Tanner stages, BMI or physical activity. In male ICSI adolescents, a tendency towards lower inhibin B (−14.8 pg/ml, 95% CI: −34.2 to 4.6 pg/ml), significantly higher estradiol (2.6 ng/l, 95% CI: 0.0 to 5.2 ng/l) and a significantly lower testosterone-to estradiol ratio (−0.047, 95% CI: −0.089 to −0.004) was found.
LIMITATIONS, REASONS FOR CAUTION
The all-over response rate and the willingness to participate in the blood test and medical examination were very low in the control group. Participating control families may have greater health awareness, and selection bias cannot be ruled out. Hormonal data in the females were measured irrespective of the cycle day and restricted to those not using hormonal contraception. Some parameters from the questionnaire data such as usage of hormonal contraception might suffer from reporting bias. As this is an observational study, we can draw only limited causal conclusions from the findings.
WIDER IMPLICATIONS OF THE FINDINGS
Differences in male reproductive hormones may indicate altered testicular function. However, at this time possible consequences for later reproductive success are unknown.
STUDY FUNDING/COMPETING INTEREST(S)
DFG research grant KA 1643/4-1. The authors declare no conflict of interest.
Summary Since approval by the U.S. Food and Drug Administration (FDA) in December 2002, teriparatide (recombinant 1-34 PTH; Forteo®) has been safely used by more than 430,000 patients. Prior to FDA ...approval, however, there was concern that teriparatide might increase the risk for patients to develop osteosarcoma, as almost 45% of the rats treated with this drug at the highest-tested dose level developed this aggressive form of bone cancer. Balancing the proven benefits of teriparatide shown by clinical trials with the theoretical risk for teriparatide-induced human osteosarcoma, the FDA mandated both a ‘black-box' warning of this potential side-effect and a company-sponsored postmarketing surveillance program. As a participating institute of that surveillance program, we report upon the second person with potential teriparatide-induced osteosarcoma, in this case, complicated by a history of pelvic radiation. Introduction Given the theoretic risk of the drug teriparatide and the known risk of radiation in inducing osteosarcoma, we raise the issue of whether teriparatide magnified the risk of radiation-induced osteosarcoma in our patient and try to determine which factor played the predominant role in the development of his disease. Methods We analyzed preclinical rat data, human clinical experience with teriparatide, and our patient's clinical history to assess the human risk of teriparatide and radiation exposure. Results After the first case of suspected osteosarcoma was reported in December 2005, we encountered a second possible teriparatide-induced osteosarcoma less than a year later. Review of the preclinical animal data would suggest that teriparatide is safe for human use when used as recommended by the manufacturer. Given the location of the sarcoma within the field of radiation and the limited exposure to teriparatide before diagnosis, it is unlikely that teriparatide played the predominant role in the emergence of this patient's osteosarcoma. We cannot, however, exclude the possibility that teriparatide magnified the carcinogenic effect of radiation therapy to induce the osteosarcoma. Conclusion Of more than 430,000 persons who have received teriparatide for treatment of severe osteoporosis, we report the second patient to develop osteosarcoma. Although teriparatide reduces osteoporosis-related fractures in select patient populations, important contraindications, such as prior radiation exposure, should be considered before use.
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