Functional hypothalamic amenorrhea: gut microbiota composition and the effects of exogenous estrogen administration

Functional hypothalamic amenorrhea (FHA) is characterized by estrogen deficiency that significantly impacts metabolic, bone, cardiovascular, mental, and reproductive health. Given the importance of environmental factors such as stress and body composition, and particularly considering the importance of estrogens in regulating the gut microbiota, some changes in the intestinal microenvironment are expected when all of these factors occur simultaneously. We aimed to assess whether the gut microbiota composition is altered in FHA and to determine the potential impact of hormonal replacement therapy (HRT) on the gut microbiota. This prospective observational study included 33 patients aged 18-34 yr with FHA and 10 age-matched healthy control women. Clinical, hormonal, and metabolic evaluations were performed at baseline for the FHA group only, whereas gut microbiota profile was assessed by 16S rRNA gene amplicon sequencing for both groups. All measurements were repeated in patients with FHA after receiving HRT for 6 mo. Gut microbiota alpha diversity at baseline was significantly different between patients with FHA and healthy controls (P < 0.01). At the phylum level, the relative abundance of Fusobacteria was higher in patients with FHA after HRT (P < 0.01), as was that of Ruminococcus and Eubacterium at the genus level (P < 0.05), which correlated with a decrease in circulating proinflammatory cytokines. FHA is a multidimensional disorder that is interconnected with dysbiosis through various mechanisms, particularly involving the gut-brain axis. HRT appears to induce a favorable shift in the gut microbiota in patients with FHA, which is also associated with a reduction in the systemic inflammatory status.NEW & NOTEWORTHY Our study marks the first comprehensive analysis of gut microbiota composition in FHA and the impact of HRT on it, along with biochemical, anthropometric, and psychometric aspects. Our results indicate distinct gut microbiota composition in patients with FHA compared with healthy individuals. Importantly, HRT prompts a transition toward a more beneficial gut microbiota profile and reduced inflammation. This study validates the concept of FHA as a multifaceted disorder interlinked with dysbiosis, particularly involving the gut-brain axis.

An Investigation of Metabolic Risk Factors and Gut Microbiota in Unexplained Syncope

BACKGROUND

The pathogenesis of many syncopal episodes remains unexplained. Intestinal dysbiosis could be involved in the pathophysiological mechanisms of syncope due to its connection with the central nervous system via the microbiota-gut-brain axis. This pilot study aimed to explore the specific cardiometabolic risk factors and gut microbiota in unexplained syncope (US), compared to other types of syncope, to assess their similarity or verify their different origins.

METHODS

We studied 86 participants with syncope, who were divided into four groups: an orthostatic syncope group (OH, n = 24), a neuromediated syncope group (NMS, n = 26), a cardiological syncope group (CS, n = 9), and an unexplained syncope group (US, n = 27). We evaluated the anthropometric, clinical, and metabolic characteristics of the four groups; the α- and β-diversity; and the differences in the abundance of the microbial taxa.

RESULTS

The US group had a lower incidence of systolic hypertension at the first visit and a lower frequency of patients with nocturnal hypertension than the CS group. Compared to the OH and NMS groups, the US group had a higher incidence of carotid plaques and greater carotid intima-media thickness, respectively. The microbiota differed significantly between the US and CS groups, but not between the US group and the OH or NMS group.

CONCLUSIONS

We observed significant differences in the gut microbiota between CS and US. Future studies are necessary to evaluate the involvement of the gut microbiota in the complex pathogenesis of syncope and whether its analysis could support the interpretation of the pathophysiological mechasnisms underlying some episodes classifiable as US.

Gut Microbiota Ecological and Functional Modulation in Post-Stroke Recovery Patients: An Italian Study

Ischemic stroke (IS) can be caused by perturbations of the gut-brain axis. An imbalance in the gut microbiota (GM), or dysbiosis, may be linked to several IS risk factors and can influence the brain through the production of different metabolites, such as short-chain fatty acids (SCFAs), indole and derivatives. This study examines ecological changes in the GM and its metabolic activities after stroke. Fecal samples of 10 IS patients were compared to 21 healthy controls (CTRLs). GM ecological profiles were generated via 16S rRNA taxonomy as functional profiles using metabolomics analysis performed with a gas chromatograph coupled to a mass spectrometer (GC-MS). Additionally fecal zonulin, a marker of gut permeability, was measured using an enzyme-linked immuno assay (ELISA). Data were analyzed using univariate and multivariate statistical analyses and correlated with clinical features and biochemical variables using correlation and nonparametric tests. Metabolomic analyses, carried out on a subject subgroup, revealed a high concentration of fecal metabolites, such as SCFAs, in the GM of IS patients, which was corroborated by the enrichment of SCFA-producing bacterial genera such as Bacteroides, Christensellaceae, Alistipes and Akkermansia. Conversely, indole and 3-methyl indole (skatole) decreased compared to a subset of six CTRLs. This study illustrates how IS might affect the gut microbial milieu and may suggest potential microbial and metabolic biomarkers of IS. Expanded populations of Akkermansia and enrichment of acetic acid could be considered potential disease phenotype signatures.

Analysis of gut microbiota in patients with Williams-Beuren Syndrome reveals dysbiosis linked to clinical manifestations

Williams-Beuren syndrome (WBS) is a multisystem genetic disease caused by the deletion of a region of 1.5-1.8 Mb on chromosome 7q11.23. The elastin gene seems to account for several comorbidities and distinct clinical features such including cardiovascular disease, connective tissue abnormalities, growth retardation, and gastrointestinal (GI) symptoms. Increasing evidence points to alterations in gut microbiota composition as a primary or secondary cause of some GI or extra-intestinal characteristics. In this study, we performed the first exploratory analysis of gut microbiota in WBS patients compared to healthy subjects (CTRLs) using 16S rRNA amplicon sequencing, by investigating the gut dysbiosis in relation to diseases and comorbidities. We found that patients with WBS have significant dysbiosis compared to age-matched CTRLs, characterized by an increase in proinflammatory bacteria such as Pseudomonas, Gluconacetobacter and Eggerthella, and a reduction of anti-inflammatory bacteria including Akkermansia and Bifidobacterium. Microbial biomarkers associated with weight gain, GI symptoms and hypertension were identified. Gut microbiota profiling could represent a new tool that characterise intestinal dysbiosis to complement the clinical management of these patients. In particular, the administration of microbial-based treatments, alongside traditional therapies, could help in reducing or preventing the burden of these symptoms and improve the quality of life of these patients.

Identification of far-red light acclimation in an endolithic Chroococcidiopsis strain and associated genomic features: Implications for oxygenic photosynthesis on exoplanets

Deserts represent extreme habitats where photosynthetic life is restricted to the lithic niche. The ability of rock-inhabiting cyanobacteria to modify their photosynthetic apparatus and harvest far-red light (near-infrared) was investigated in 10 strains of the genus Chroococcidiopsis, previously isolated from diverse endolithic and hypolithic desert communities. The analysis of their growth capacity, photosynthetic pigments, and apcE2-gene presence revealed that only Chroococcidiopsis sp. CCMEE 010 was capable of far-red light photoacclimation (FaRLiP). A total of 15 FaRLiP genes were identified, encoding paralogous subunits of photosystem I, photosystem II, and the phycobilisome, along with three regulatory elements. CCMEE 010 is unique among known FaRLiP strains by undergoing this acclimation process with a significantly reduced cluster, which lacks major photosystem I paralogs psaA and psaB. The identification of an endolithic, extremotolerant cyanobacterium capable of FaRLiP not only contributes to our appreciation of this phenotype’s distribution in nature but also has implications for the possibility of oxygenic photosynthesis on exoplanets.

A systematic review of the effects of adding neostigmine to local anesthetics for neuraxial administration in obstetric anesthesia and analgesia

BACKGROUND

Drugs used in obstetric patients must accomplish two goals: efficacy and safety for both mother and fetus. Neostigmine has been co-administered epidurally and intrathecally with local anesthetics and other adjuncts in the obstetric setting. The aim of this meta-analysis was to assess the efficacy and incidence of adverse events related to the use of neostigmine in obstetric anesthesia.

METHODS

A meta-analysis of randomized-controlled human trials was conducted using the data sources Google Scholar and PubMed (updated 1 November 2014). Inclusion criteria were: random allocation to treatment; comparison of neostigmine or neostigmine with local anesthetics and/or other adjuvants versus placebo or placebo with local anesthetics and/or other adjuvants; and approval by an ethics committee.

RESULTS

The use of neostigmine as an adjuvant in neuraxial anesthesia is associated with a reduction in the dose of local anesthetic during labor analgesia and postoperative analgesia following cesarean section: mean reduction of local anesthetic (ropivacaine or bupivacaine) vs. control -4.08 (95% CI -6.7 to -1.5) mg/h (P=0.002). The risk of nausea was increased vs. control with intrathecal neostigmine (OR 8.99 [95% CI 4.74 to 17.05], P <0.001) but not with epidural neostigmine (OR 0.97 [95% CI 0.46 to 2.05], P=0.94). Use of neuraxial neostigmine was associated with a decrease in the risk of pruritus but there was no increase in the incidence of hypotension, dizziness or sedation and no effect on the incidence of abnormal fetal heart rate patterns or Apgar scores.

CONCLUSIONS

Neuraxial administration of neostigmine significantly reduces local anesthetic consumption without serious adverse side effects to the mother or fetus. However, neostigmine is only recommended for epidural administration as intrathecal use significantly increases the incidence of maternal nausea and vomiting.

Evaluation of the use of human Mesenchymal Stem Cells for acute toxicity tests

In vitro cytotoxicity tests are typically carried out with transformed, immortalized cell lines or primary cells. Immortalized cells are readily available and easily maintained, although they usually show anomalous behavior and phenotypes, which do not reflect the mechanisms observed in their normal homologous cells. Primary cells are indeed considered a better option as model systems for predicting toxicological behavior, although they are limited in quantity and suffer from batch-to-batch variation due to the need to isolate them freshly for each study. In particular, human Mesenchymal Stem Cells (hMSCs) have never been adopted in order to develop in vitro model systems for acute toxicity tests of chemicals. Therefore, the aim of this study was to verify the possibility of using hMSCs as an alternative method to estimate in vivo starting dose for acute toxicity. As suggested by ICCVAM, 12 reference chemicals were assessed in the present study and a Neutral Red Uptake assay was performed. It is shown for the first time that MSCs isolated from human bone marrow can be confidently used in this area of toxicology. MSCs represent a good promise for the development of in vitro human assays and could ultimately replace, improve or overtake current predictive models in toxicology.

Experimental analysis and modelling of in vitro HUVECs proliferation in the presence of various types of drugs

OBJECTIVES

This study focuses on experimental analysis and corresponding mathematical simulation of in vitro HUVECs (human umbilical vein endothelial cells) proliferation in the presence of various types of drugs.

MATERIALS AND METHODS

HUVECs, once seeded in Petri dishes, were expanded to confluence. Temporal profiles of total count obtained by classic haemocytometry and cell size distribution measured using an electronic Coulter counter, are quantitatively simulated by a suitable model based on the population balance approach. Influence of drugs on cell proliferation is also properly simulated by accounting for suitable kinetic equations.

RESULTS AND DISCUSSION

The models' parameters have been determined by comparison with experimental data related to cell population expansion and cell size distribution in the absence of drugs. Inhibition constant for each type of drug has been estimated by comparing the experimental data with model results concerning temporal profiles of total cell count. The reliability of the model and its predictive capability have been tested by simulating cell size distribution for experiments performed in the presence of drugs. The proposed model will be useful in interpreting effects of selected drugs on expansion of readily available human cells.

Marginal adaptation of fixed prosthodontics: a new in vitro 360-degree external examination procedure

PURPOSE

This study evaluated the marginal fit of experimental and custom-made fixed prosthetic restorations through a new 360-degree external examination. The minimum number of gap measurements required to produce relevant results for gap analysis was also investigated.

MATERIALS AND METHODS

The marginal fit of six experimental and eight custom-made crowns was observed microscopically by means of a mechanical device, and software was employed to measure the gap. Two crowns, chosen from among the 14 previously evaluated, were reanalyzed to determine the minimum number of gap measurements required to produce significant results for gap analysis.

RESULTS

The precision obtained with the custom-made crowns differed from that of the experimental specimens. The minimum number of measurements required to produce a sample mean value within +/- 5 microm of the mean, calculated over 360 measurements, taking standard error of the means < or = 4 microm, was 18 for experimental and 90 for custom-made crowns, for both equidistant measurement spacing and randomly selected points.

CONCLUSION

Differences in fit between experimental specimens and custom-made ones showed that experimental results might not always be obtained in clinical practice. Within the limitations of the protocol of this study, the minimum number of measurements required to ensure relevant results for gap analysis was 18 for experimental and 90 for custom-made crowns.

Glycosaminoglycans: urinary excretion in children with myelomeningocele

BACKGROUND

The main consequences of neurogenic bladder dysfunction are renal damage related to high intravesical pressure, vesicoureteral reflux (VUR) and urinary tract infections (UTIs). Neurologic impairment, UTIs and VUR are known to be linked with a potential for renal scarring. Of paramount importance as predisposing conditions for UTIs in neurogenic bladder are poor bladder drainage and detrusor-sphincter dyssynergy which cause further abnormalities on the internal bladder surface and, consequently, a bladder wall rich in glycosaminoglycans (GAGs).

MATERIALS AND METHODS

The aim of this study is to investigate the correlation between GAG excretion and bladder wall degeneration in 43 patients affected by spina bifida (SB) and 40 healthy age-matched control children.

RESULTS

The amounts of GAGs excreted vary greatly in SB patients aged from 0 to 5 years, and values are comparable to those observed in normal controls. They are significantly higher in children over 5 years of age.

CONCLUSION

The increased excretion of GAGs in older SB patients is an important parameter in the evaluation of the physiopathological condition of the bladder wall and hence may be considered a possible marker for monitoring the beginning of bladder damage.