[The mediating role of anxiety and depression for family members of ICU patients in perceived social support and fatigue].

To analyze the mediating role of anxiety and depression in perceived social support and fatigue in ICU patients' families, and to provide a theoretical evidence for alleviating their fatigue status. A total of 223 family members of ICU patients who received treatment at the Affiliated Hospital of Jiangnan University from October 2020 to April 2021 were selected as the study subjects. The general data questionnaire, perceived social support scale (PSSS), generalized anxiety disorder scale (GAD-7), patient health questionnaire (PHQ-9) and fatigue assessment instrument (FAI) were used to conduct a survey. Among 223 family members of ICU patients, 155(69.51%) had fatigue problems. There were statistically significant differences in total fatigue scores of ICU patients' family members in terms of gender, age, education level, relationship with patients, residence, payment method and per capita monthly income (P<0.05). Anxiety, depression and fatigue were negatively correlated with perceived social support (r are -0.353, -0.276 and -0.416, respectively, all P<0.01). Depression and fatigue were positively correlated with anxiety (r are 0.808 and 0.703, respectively, all P<0.01), and fatigue was also positively correlated with depression (r= 0.665, P<0.01). Anxiety and depression had a partial mediating effect on perceived social support and fatigue, and the total indirect effect size was 52.64%. Comprehensive intervention on the level of social support, anxiety and depression is helpful to improve the fatigue status of ICU patients' family members.

[Effect of KIR/HLA receptor-ligand mode on prognosis of single unrelated cord blood transplantation in patients with hematological malignancies].

Objective: To explore the impact of the natural killer cell immunoglobulin-like receptor/human leukocyte antigen (KIR/HLA) receptor-ligand model in single unrelated cord blood transplantation (sUCBT) . Methods: Between July 2012 and June 2018, 270 patients with malignant hematologic diseases receiving single-unit UCBT were divided into two groups. Group 1 (n=174) patients lacked a C-ligand for inhibitory KIR on UCB NK cells (patients homozygous C1/C1 or C2/C2) . Group 2 (n=96) patients expressed both C ligands for inhibitory KIR in the receptor (patients heterozygous C1/C2) . Results: A total of 270 patients (146 males, 124 females) with a median age of 13 years (1-62) were included in this retrospective study. All patients received a myeloablative conditioning regimen (without ATG) . The ratio of neutrophil engraftment for group 1 and 2 were both 98.9%, the median time of neutrophil engraftment for group 1 and 2 was 16 (10-41) days vs 17 (11-33) days (P=0.705) . The ratio of platelet engraftment was 88.5% for group 1 and 87.5% for group 2, the median time of platelet engraftment was 35 (11-113) days vs 38.5 (13-96) days (P=0.317) . The cumulative incidence of Ⅱ-Ⅳ acute GVHD in 100 days was 38.7% (95%CI 31.4%-45.9%) for group 1 and 50.0% (95%CI 39.6%-59.6%) for group 2 (P=0.075) , but multivariate analysis showed that HLA-C ligand absence was an independent protective factor for Ⅱ-Ⅳ acute GVHD after transplantation (P=0.036) . Patients in absence of a C-ligand for inhibitory KIRs (Group 1) showed a lower relapse rate than patients with both C-ligands (group 2) : 17.7% (95%CI 11.7%-24.9%) vs 22.7% (95%CI 4.4%-32.2%) after 3 years (P=0.288) . The median follow-up time was 742 (335-2 512) days. The 3-year OS was 72.1% for group 1 and 60.5% for group 2 (P=0.079) . There was no statistically significant difference between the two groups in 3-year disease-free survival [64.9% (95%CI 56.2%-72.3%) vs 55.4% (95%CI 44.4%-65.0%) (χ(2)=3.027, P=0.082) ]. Non-relapse mortality for group 1 was 12.1% (95%CI 7.7%-17.4%) and for group 2 was 16.7% (95%CI 10.0%-24.8%) (P=0.328) . Conclusion: Patients lacking a KIR-ligand of HLA group C1 or C2 had a lower incidence of grades Ⅱ-Ⅳ acute GVHD after sUCBT.

PCR screening reveals considerable unexploited biosynthetic potential of ansamycins and a mysterious family of AHBA-containing natural products in actinomycetes.

AIMS: Ansamycins are a family of macrolactams that are synthesized by type I polyketide synthase (PKS) using 3-amino-5-hydroxybenzoic acid (AHBA) as the starter unit. Most members of the family have strong antimicrobial, antifungal, anticancer and/or antiviral activities. We aimed to discover new ansamycins and/or other AHBA-containing natural products from actinobacteria. METHODS AND RESULTS: Through PCR screening of AHBA synthase gene, we identified 26 AHBA synthase gene-positive strains from 206 plant-associated actinomycetes (five positives) and 688 marine-derived actinomycetes (21 positives), representing a positive ratio of 2·4-3·1%. Twenty-five ansamycins, including eight new compounds, were isolated from six AHBA synthase gene-positive strains through TLC-guided fractionations followed by repeated column chromatography. To gain information about those potential ansamycin gene clusters whose products were unknown, seven strains with phylogenetically divergent AHBA synthase genes were subjected to fosmid library construction. Of the seven gene clusters we obtained, three show characteristics for typical ansamycin gene clusters, and other four, from Micromonospora spp., appear to lack the amide synthase gene, which is unusual for ansamycin biosynthesis. The gene composition of these four gene clusters suggests that they are involved in the biosynthesis of a new family of hybrid PK-NRP compounds containing AHBA substructure. CONCLUSIONS: PCR screening of AHBA synthase is an efficient approach to discover novel ansamycins and other AHBA-containing natural products. SIGNIFICANCE AND IMPACT OF THE STUDY: This work demonstrates that the AHBA-based screening method is a useful approach for discovering novel ansamycins and other AHBA-containing natural products from new microbial resources.

End-group determination of oligosaccharides: a gas chromatography-mass spectrometry/mass spectrometry method for distinguishing between all D-aldohexoses and D-ketohexoses.

A method for end-group determination of oligosaccharides is described, which involves conversion of the reducing monosaccharide into a 1-deoxy-1-hydrazinohexitol heptaacetate (aldohexoses) or an epimeric pair of 2-deoxy-2-hydrazinohexitol heptaacetates (2-ketohexoses). Products are linear and unique to each aldohexose or ketohexose. Methods are reported for separation of all stereoisomers of the derivatives on single columns by gas chromatography. Gas chromatography-mass spectrometry/mass spectrometry with electron-impact ionization enabled the 1-deoxy-1-hydrazinohexitol heptaacetates and 2-deoxy-2-hydrazinohexitol heptaacetates to be independently identified in each others presence. Chemical-ionization mass spectrometry/mass spectrometry permitted derivatives to be identified in subpicomolar quantities. The non-acetylated compounds could also be identified as their hydrochlorides by 1H NMR spectroscopy.

Neutral core oligosaccharides of bovine submaxillary mucin--use of lead tetraacetate in the cold for establishing branch positions.

Oligosaccharide alditols were released from bovine submaxillary mucin by alkaline borohydride treatment. The fractions containing smaller neutral oligosaccharides were separated by HPLC, to give, in the mono-, di- and trisaccharide-alditol sizes, 19 different structures, in addition to three fucosylated tetrasaccharide alditols. Molecules were identified by NMR spectroscopy, electrospray-mass-spectrometry-mass-spectrometry, permethylation analyses, and highly selective Pb(OAc)4 oxidation at -30 degrees C, followed by borohydride reduction. Pb(OAc)4 oxidation was found to be generally applicable in identifying the branch position(s) of substitutions for all core structures. Among the isolated oligosaccharide alditols were structures not previously reported, including 12 structures not reported from bovine submaxillary mucin, and four structures (three core structures) not found in the Carbbank database.

Malassezia furfur folliculitis in cancer patients. The need for interaction of microbiologist, surgical pathologist, and clinician in facilitating identification by the clinical microbiology laboratory.

Malassezia furfur (MF) is a lipophilic yeast which can be found as a member of the indigenous microbiota of human skin. In immunocompromised transplant patients, MF can cause a distinctive folliculitis which is a clinical look-alike to Candida folliculitis, the latter of more potentially devastating significance. Recovery of MF in culture is dependent upon the addition to culture media of an exogenous source of fatty acids, such as olive oil. The addition of an extra Sabourauds plate with an olive oil overlay to the routine set of media used to inoculate all skin biopsy specimens in order to detect MF is labor-intensive and not cost-effective. Thus, MF may not be isolated in cases of MF folliculitis unless the clinical microbiology laboratory is put on alert by the clinical suspicions of the attending physician, or by histopathologic findings suggestive of folliculitis revealed by review of surgical pathology slides. The clinical, pathological, and microbiological findings of two cases of MF folliculitis are presented where an interactive approach featuring communication between the microbiologist, the surgical pathologist, and the clinician guided the microbiology laboratory to the isolation and identification of isolates of MF that were clinically-relevant. These cases underscore how a combined approach which features communication between the laboratory and the clinical services always provides superior guidance in the diagnosis and therapy of infectious diseases.

Structure-activity analysis of antagonism of the feedback inhibition of thymidine kinase.

The effects of a variety of 5-, 5'-, and 3'-substituted deoxyuridine derivatives on the cytoplasmic thymidine kinase (EC 2.7.1.21) purified from a human colon carcinoma cell line, HCT 116, were determined. Of particular interest was elucidation of the structural features important for antagonism of the feedback inhibition of thymidine kinase exerted by thymidine triphosphate. Substitutions at the 5-position altered the potency of the 5'-modified compounds. The replacement of the 5-hydrogen with a methyl group or an iodine greatly increased the affinity of compounds for the thymidine kinase. This was evident for enzyme substrates with 5'-hydroxyl groups [2'-deoxyuridine (dUrd), 2'-deoxythymidine (dThd) and 5-iodo-2'-deoxyuridine (IdUrd)], feedback inhibitors with 5'-triphosphate substitutions (dUTP, dTTP and IdUTP), and for 5'-amino derivatives [5'-amino-2',5'-dideoxyuridine (5'-AdUrd), 5'-amino-2'-5'-dideoxythymidine (5'-AdThd) and 5-iodo-5'-amino-2',5'-dideoxyuridine (5'-AIdUrd)]. Qualitatively, however, the 5-substitutions did not affect the nature of the interactions with dThd kinase. For example, in the presence of dTTP, 5'-AdUrd stimulated dThd kinase activity as much as 5'-AdThd, but approximately a 100-fold greater concentration of 5'-AdUrd was required. Similar results were obtained using intact cells in which substitutions at the 5-position affected the potency, but not the efficacy, of the 5'-amino derivatives to stimulate dThd phosphorylation. In contrast, substitutions at the 5'-position did alter the nature of the interaction with dThd kinase. Thus, the 5'-hydroxyl compounds, dUrd, dThd and IdUrd, did not reverse the enzyme inhibition produced by dTTP nor did they stimulate dThd uptake in intact cells. 5'-Deoxy-5'-(ethylthio)thymidine, 5'-deoxy-5'-[(2-hydroxyethyl)thio]thymidine, and dTMP, but not dTDP, also antagonized the inhibition of dThd kinase produced by dTTP. In comparison to 5'-AdThd, the 3'-amino derivatives, 3'-AdThd and 3'-5'-diAdThd, were much less potent, but still efficacious, antagonists of feedback inhibition. These results indicate that a wide range of dUrd derivatives can disrupt the regulation of dThd kinase and provide leads for the development of new nucleotide analogues.

Ethyl alcohol-induced cardiovascular malformations in the chick embryo.

Chick embryos incubated for 72-80 hours were exposed to various volumes (0.20-0.40 m1/egg) of 50% ethyl alcohol. Examination of embryos at day 14 of incubation showed that higher doses of ethanol decreased the survival rate of embryos compared with control embryos. Three major categories of cardiovascular malformations were observed in this study: intracardiac anomalies characterized primarily by isolated ventricular septal defect, ventricular septal defect with overriding aorta, double outlet right ventricle or common aorticopulmonary trunk; aortic arch anomalies; and subclavian artery anomalies. Frequencies of embryos with intracardiac anomalies were equal to or greater than 64.8% in the six groups exposed to ethanol. Administration of ethanol also induced high frequencies of embryos with subclavian artery anomalies (11.2-89.1%). Absence or hypoplasia of the right and/or left secondary subclavian artery was commonly associated with persistence of the corresponding primary subclavian artery. Bilateral absence and/or hypoplasia of the secondary subclavian arteries was more common than unilateral anomalies, whereas absence of the left secondary subclavian artery was more commonly observed than an absent right secondary subclavian artery. No embryos in the two control groups combined (n = 94) demonstrated aortic arch or subclavian artery anomalies.