Risk Prediction Models of Natural Menopause Onset: A Systematic Review

CONTEXT

Predicting the onset of menopause is important for family planning and to ensure prompt intervention in women at risk of developing menopause-related diseases.

OBJECTIVE

We aimed to summarize risk prediction models of natural menopause onset and their performance.

METHODS

Five bibliographic databases were searched up to March 2022. We included prospective studies on perimenopausal women or women in menopausal transition that reported either a univariable or multivariable model for risk prediction of natural menopause onset. Two authors independently extracted data according to the CHARMS (critical appraisal and data extraction for systematic reviews of prediction modelling studies) checklist. Risk of bias was assessed using a prediction model risk of bias assessment tool (PROBAST).

RESULTS

Of 8132 references identified, we included 14 articles based on 8 unique studies comprising 9588 women (mainly Caucasian) and 3289 natural menopause events. All included studies used onset of natural menopause (ONM) as outcome, while 4 studies also predicted early ONM. Overall, there were 180 risk prediction models investigated, with age, anti-Müllerian hormone, and follicle-stimulating hormone being the most investigated predictors. Estimated C-statistic for the prediction models ranged from 0.62 to 0.95. Although all studies were rated at high risk of bias mainly due to the methodological concerns related to the statistical analysis, their applicability was satisfactory.

CONCLUSION

Predictive performance and generalizability of current prediction models on ONM is limited given that these models were generated from studies at high risk of bias and from specific populations/ethnicities. Although in certain settings such models may be useful, efforts to improve their performance are needed as use becomes more widespread.

Protein expression of KIT, BRAF, GNA11, GNAQ and RASSF1 in feline diffuse iris melanomas

Feline iris melanoma, the most common feline intraocular tumour, has a reported metastatic rate of 19-63%. However, there is a lack of knowledge about its molecular biology. Previous studies have reported that feline iris melanomas do not harbour mutations comparable to common mutations found in their human counterpart. Nevertheless, there are differences in the gene expression patterns. The aim of this study was to investigate the protein expression of B-RAF oncogene serine/threonine kinase (BRAF), G protein subunit alpha q (GNAQ) and 11 (GNA11), KIT proto-oncogene receptor tyrosine kinase (KIT), and Ras association family member 1 (RASSF1) in feline iris melanomas. Fifty-seven formalin-fixed paraffin embedded (FFPE) iris melanomas and 25 FFPE eyes without ocular abnormalities were stained with antibodies against the respective proteins using immunofluorescence. Averaged pixel intensities/μm² and percentage of stained area from total tissue area were measured and the results were compared. Compared to the control group, iris melanomas showed overexpression of BRAF, GNAQ, GNA11 and KIT. The higher expression of BRAF, GNAQ, GNA11 and KIT in feline iris melanomas suggest that these proteins may play a key role in the development of feline iris melanomas and KIT may present a possible target for future therapies in cats with feline iris melanomas.

Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

Evaluation of SmartFlare probe applicability for verification of RNAs in early equine conceptuses, equine dermal fibroblast cells and trophoblastic vesicles

Live cell RNA imaging has become an important tool for studying RNA localisation, dynamics and regulation in cultured cells. Limited information is available using these methods in more complex biological systems, such as conceptuses at different developmental stages. So far most of the approaches rely on microinjection of synthetic constructs into oocytes during or before fertilisation. Recently, a new generation of RNA-specific probes has been developed, the so named SmartFlare probes (Merck Millipore). These consist of a central 15-nm gold particle with target-specific DNAs immobilised on its surface. Because of their central gold particle, SmartFlare probes are detectable by transmission electron microscopy. The aim of the present study was to investigate the uptake and distribution of SmartFlare probes in equine conceptuses at developmental stages suitable for embryo transfer (Days 6-10), equine trophoblast vesicles and equine dermal fibroblast cell cultures, and to determine whether differences among these cell types and structures exist. Probe uptake was followed by transmission electron microscopy and fluorescence microscopy. Although the embryonic zona pellucida did not reduce uptake of the probe, the acellular capsule fully inhibited probe internalisation. Nanogold particles were taken up by endocytosis by all cell types examined in a similar manner with regard to time and intracellular migration. They were processed in endosomal compartments and accumulated within lysosomal structures after longer incubation times. In conclusion, the SmartFlare probe is applicable in equine conceptuses, but its use is limited to the developmental stages before the formation of the embryonic capsule.

Strukturverfeinerungen an den Cobalt(II)hexammin-Komplexen [Co(NH3)6](BF4)2 und [Co(NH3)6](PF6)2/ Structure Refinements of the Cobalt(II)hexammine Complexes [Co(NH3)6](BF4)2 and [Co(NH3)6](PF6)2

Using single crystal X-ray data of the compounds [Co(NH3)6](BF4)2 (a = 1129.8(1) pm) and [Co(NH3)6](PF6)2 (a = 1195.9(1) pm) the anti-K2PtCl6 structure, space group Fm3m , was confirmed for both complexes (R ≈ 0.05). Fourier methods revealed essential disorder for the BF4 - anion only, the fluorine atoms of which remain concentrated, however, within the octants of the subcell opposite to the cobalt atoms. No indication of H bridging is found in the IR spectra. The Co-N bond lengths of 218.3(2) and 218.7(10) pm, resp.. in the cobalt(II)hexammine group are unusual long in both compounds.

Sedation of children during measurement of CSF opening pressure: lack of standardisation in German children with pseudotumor cerebri

BACKGROUND

Diagnosis of pseudotumor cerebri (PTC) requires proper documentation of raised CSF opening-pressure. In childhood results may not be reliable due to insufficient sedation/analgesia or drug effects. We aimed to evaluate the current practice regarding pain and stress management in children undergoing lumbar puncture (LP) for pressure measurement.

METHODS

A one-year survey was conducted involving 368 German paediatric departments. All children with newly diagnosed PTC should be reported. Details analyzed here included: age, sex, CSF opening pressure and type of procedural sedation and analgesia (PSA) during LP.

RESULTS

61 patients were analyzed, aged 6 months to 17 years. 29 patients (47%) did not receive any kind of PSA. In children receiving PSA the following regimens were used: Ketamine; Midazolam; Ketamine + Midazolam; Midazolam + Piritramide; Propofol; Profofol + Midazolam; general anaesthesia.

CONCLUSION

Pain and stress management in children undergoing LP for CSF opening pressure measurement is often insufficient. Pain, stress and the variability of PSA regimen may be confounders of pressure measurement. In order to prevent false diagnoses of PTC and to obtain comparable results at different centers, a general consensus on PSA in children undergoing LP for CSF opening pressure measurements is required.

Fluorescence correlation spectroscopy reveals fast optical excitation-driven intramolecular dynamics of yellow fluorescent proteins

Fast excitation-driven fluctuations in the fluorescence emission of yellow-shifted green fluorescent protein mutants T203Y and T203F, with S65G/S72A, are discovered in the 10(-6)-10(-3)-s time range, by using fluorescence correlation spectroscopy at 10(-8) M. This intensity-dependent flickering is conspicuous at high pH, with rate constants independent of pH and viscosity with a minor temperature effect. The mean flicker rate increases linearly with excitation intensity for at least three decades, but the mean dark fraction of the molecules undergoing these dynamics is independent of illumination intensity over approximately 6 x 10(2) to 5 x 10(6) W/cm(2). These results suggest that optical excitation establishes an equilibration between two molecular states of different spectroscopic properties that are coupled only via the excited state as a gateway. This reversible excitation-driven transition has a quantum efficiency of approximately 10(-3). Dynamics of external protonation, reversibly quenching the fluorescence, are also observed at low pH in the 10- to 100-microseconds time range. The independence of these two bright-dark flicker processes implies the existence of at least two separate dark states of these green fluorescent protein mutants. Time-resolved fluorescence measurements reveal a single exponential decay of the excited state population with 3.8-ns lifetime, after 500-nm excitation, that is pH independent. Our fluorescence correlation spectroscopy results are discussed in terms of recent theoretical studies that invoke isomerization of the chromophore as a nonradiative channel of the excited state relaxation.

Optical methods for exploring dynamics of single copies of green fluorescent protein

Single copies of four different phenolate ion mutants of the green fluorescent protein (GFP) exhibit a complex blinking and fluctuating behavior, a phenomenon that is hidden in measurements on large ensembles. Both total internal reflection microscopy and scanning confocal microscopy can be used to study the blinking dynamics, and autocorrelation analysis yields histograms of the correlation times for many individual molecules. While the total internal reflection method can follow several single molecules simultaneously, the confocal method offers higher time resolution at the expense of parallelism. We compare and contrast the two methods in terms of the ability to follow the complex dynamics of this system.

Prospective randomized trial of two different immunoadsorbers in severe systemic lupus erythematosus

Experiences with extracorporeal therapy in systemic lupus erythematosus have been published over the last 20 years and more. In addition to plasmapheresis, specific adsorption columns have been developed to deplete pathogenic antibodies and immune complexes in the plasma of patients with SLE. We conducted a prospective randomized trial to compare the efficacy of a disposable adsorption column, which contained a specific ligand, phenylalanine (IMPH-350|Pt, Diamed, Köln, Germany) with a regenerable Ig-adsorbing column containing sheep anti-human antibodies (Ig-Therasorb|Pt, Therasorb, München, Germany). Twenty SLE patients inadequately controlled with corticosteroids, anti-malarials, azathioprine or cyclosporine A, had strong evidence of disease in general, or an organ related SLAM score. They were randomized to receive either a perfusion of IMPH-350, or Ig-Therasorb, immunoadsorbed with 2.5 ml of plasma, three times each. The treatment regime was repeated after 4 weeks when the response was limited or non-existent. Response was defined as a reduction in the SLAM score of at least 30%. SLAM scores in the IMPH group decreased from 14.3+/-5.6 to 9.2+/-6.2 after 1 month and to 9.4+/-3.9 after 6 months; corresponding scores in the Ig-Therasorb group were 18.3+/-5. 5 to 11.2+/-7.6, decreasing to 9.2+/-2.9. After 1 month, 8/10 patients in both groups showed a response; after 6 months, 5/10 patients in the IMPH-350 group and 8/10 in the Ig-Therasorb group fulfilled the response criteria. Reduction of dsDNA antibodies directly after treatment was 50.8+/-6.6% in the IMPH-350 group and 61.0+/-8.0% in the IgTherasorb group. Results indicate that immunoadsorption is an additional option in the treatment of severe SLE. Choice of type of immunoadsorber and immunosuppressive treatment has to take into account the severity and chronicity of common disease activity and organ involvement, as well as economic aspects.