Internal Dynamics and Modular Peripheral Binding in Stimuli-Responsive 3 : 2 Host:Guest Complexes.

Now that the chemistry of 1 : 1 host:guest complexes is well-established, it is surprising to note that higher stoichiometry (oligomeric) complexes, especially those with excess host, remain largely unexplored. Yet, proteins tend to oligomerize, affording new functions for cell machinery. Here, we show that cucurbit[n]uril (CB[n]) macrocycles combined with symmetric, linear di-viologens form unusual 3 : 2 host:guest complexes exhibiting remarkable dynamic properties, host self-sorting, and external ring-translocation. These results highlight the structural tunability of cucurbit[8]uril (CB[8]) based 3 : 2 host:guest complexes in water and their responsiveness toward several stimuli (chemicals, pH, redox).

Completeness of reporting in systematic reviews and meta-analyses in vascular surgery.

OBJECTIVE: Systematic reviews (SRs) and meta-analyses are essential in informing clinical guidelines and decision-making. Complete reporting of SRs through compliance to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines promotes transparency, reproducibility, and consistency across the literature. The purpose of this meta-epidemiological study is to assess the completeness of reporting of SRs in the vascular surgery literature. METHODS: MEDLINE and Embase were used to search through four major vascular surgery journals and four high impact general medical journals for SRs published between 2018 and October 2022 evaluating clinical treatments for any pathology treated by a vascular surgeon. Data screening and extraction were conducted in duplicate. The reporting completeness of each included SR was measured with reference to the 27-item PRISMA checklist, and methodological quality was evaluated using the Assessing the Methodological Quality of Systematic Reviews 2 (AMSTAR 2) tool. Parametric tests were used to evaluate for associations between PRISMA score and study funding, protocol registration, publication in a higher impact factor journal, and AMSTAR 2 score. The protocol is available online: 10.17605/OSF.IO/VBC5N. RESULTS: Of 1653 articles captured in the initial search, 162 SRs were included in the final analysis. All SRs had more than one incomplete PRISMA item. The mean PRISMA score was 21.2/27 (standard deviation: 2.9, 78.5% compliance), and the mean AMSTAR 2 score was 11.7/16 (standard deviation: 1.9, 73%). SRs that had a prospectively registered protocol had a higher PRISMA score (22.9 vs 20.6, P < .001) as did those that were published in higher impact factor journals (23.3 vs 21.0, P = .017). There was a large positive correlation between an SR's PRISMA and AMSTAR 2 scores (Pearson r = 0.655, 95% confidence interval: 0.55-0.74). There were no associations between the PRISMA score and publication year (P = .067) or funding status (P = .076). CONCLUSIONS: Overall, the reporting of SRs and meta-analyses in vascular surgery is less than ideal, with several key items being consistently under-reported. Prospective registration and methodological quality as measured by AMSTAR 2 scores are positively associated with improved reporting. Authors, reviewers, and journal editors should consider these findings moving forward to encourage completeness of SR reporting. Raising awareness surrounding the value of complete reporting of SRs can aid in enhancing the quality of evidence, and journals should consider these findings in methods used to promote SR reporting.

Synthesis of Five-Membered exo-Glycals from Six-Membered 2-Iodo-endo-glycals.

Five-membered exo-glycals were synthesized from six-membered 2-iodo-endo-glycals by a metal/halogen exchange/ring-opening sequence followed by a cyclization catalyzed by Ag2CO3.

Photoredox-catalyzed hydroxymethylation of ß-ketoesters: application to the synthesis of [3.3.3] propellane lactones.

Photoredox-catalysed hydroxymethylation of ß-ketoesters substituted by an allyl subunit on the α-position afforded directly the corresponding bicyclic lactones possessing both a hydroxy group and an unsaturation. A subsequent regioselective iodoetherification led to the formation of original [3.3.3] propellane structures. Substitution of the iodine atom by various nucleophiles afforded highly functionnalized structures including triazolomethyl derivatives.

A short route to access oxaspiro[n,3,3]propellanes.

Novel access to oxaspiro[n,3,3]propellanes has been developed from bicyclic lactones directly prepared by a photochemical hydroxymethylation or alternatively by a three-step sequence. Thanks to the presence of additional hydroxy- and propargylic groups, a second cyclization catalyzed by silver or bismuth salts, led to the propellane structure which was finally transformed into spiranic derivatives by a Simmons-Smith reaction or condensation with α-ketoesters.

Relation Between URIC Acid Levels and Subclinical Hypothyroidism in Diabetic Patients.

BACKGROUND AND AIM: Subclinical hypothyroidism (SCH) is frequently seen in diabetic patients. Elevated levels of uric acid (UA) were also reported in diabetic patients. No study assessed the relation between SCH and UA levels in diabetic patients. We aimed to evaluate this relation and the association of both conditions with other clinical and laboratory parameters in diabetic patients. SUBJECTS AND METHODS: This cross-sectional study included 100 T2DM patients in addition to 50 age and sex matched healthy controls. Diabetic patients comprised 50 patients with SCH and 50 euthyroid patients. All participants were subjected to careful history taking, thorough clinical examination and standard laboratory work up. The performed investigations included fasting and postprandial blood sugar, fasting insulin levels, HbA1c levels, thyroid hormones (FT3, FT4 and TSH), renal profile and serum UA. RESULTS: Comparison between the studied groups regarding serum UA levels revealed significantly higher levels in the diabetic group (5.4 ± 1.9 versus 4.2 ± 1.0 mg/dl, p<0.001). SCH + DM patients had significantly higher UA levels in comparison to DM group (6.1 ± 1.8 versus 4.8 ± 1.7 mg/dl, p<0.001) and control group (6.1 ± 1.8 versus 4.2 ± 1.0 mg/dl, p<0.001). SCH + DM patients had significantly higher HbA1c levels (8.9 ± 1.1 versus 7.6 ± 1.3%, p<0.001), HOMA-IR (3.9 ± 0.8 versus 2.8 ± 1.0, p<0.001) and UA levels (6.1 ± 1.8 versus 4.8 ± 1.7, p<0.001). Correlation analysis identified a significant direct correlation between serum UA and HOMA-IR in DM + SCH patients (r=0.4,p=0.004). In univariate analysis, presence of SCH [OR (95% CI): 2.57 (1.07-6.15), p=0.034] and nephropathy [OR (95% CI): 4.57 (1.77-11.8), p=0.002] was significant predictors of higher (upper tertile) UA in the studied patients. However, in multivariate analysis, only nephropathy [OR (95% CI): 4.25 (1.62-11.17), p=0.003] continued to be significant while SCH showed a marginal trend [OR (95% CI): 0.43 (0.17-1.08), p=0.073]. CONCLUSION: The present study suggests an association between SCH and increased UA levels in diabetic patients.

Prevalence and Clinical Significance of Subclinical Hypothyroidism in Diabetic Peripheral Neuropathy.

BACKGROUND AND AIM: Diabetic peripheral neuropathy (DPN) is one of the most common and disabling complications of DM. Many studies documented the prevalence of clinical and subclinical hypothyroidism (SCH) in diabetic patients but not in the particular group of patients with DPN. The present study aimed to determine the prevalence of SCH in DPN patients and to evaluate its association with severity of DPN. PATIENTS AND METHODS: The present cross-sectional study was conducted on 300 consecutive patients with DPN. The clinical manifestations of DPN were documented according to the validated Arabic version of the Michigan Neuropathy Screening Instrument. Severity of DPN was categorized into mild (6-8 points), moderate (9-11 points) or severe (12+ points) according to the Toronto Clinical Scoring System. All patients were submitted to careful history-taking and full clinical and neurological examination. Patients were diagnosed with SCH if they had TSH level above the upper limit of the normal reference range in association with normal free thyroxine (FT4) level. RESULTS: SCH was prevalent in 53 patients (17.7%, 95% CI: 13.5%-22.5%). Patients with SCH had significantly higher frequency of severe DPN (52.8% versus 28.3%, p=0.003). It was also shown that patients with SCH had significantly higher HbA1c (8.4 ± 1.0 versus 7.3 ± 1.2%, p<0.001) and HOMA-IR (3.7 ± 0.8 versus 2.7 ± 0.9, p<0.001) when compared with patients without SCH. Logistic regression analysis identified patients' age [OR (95% CI): 1.06 (1.03-1.08), p<0.001], HbA1c [OR (95% CI): 2.2 (1.7-2.9), p<0.001] and SCH [OR (95% CI): 7.7 (3.6-15.5), p<0.001] as independent predictors of DPN severity. CONCLUSION: The present study showed that SCH is highly prevalent in DPN patients and is independently related to its severity.