[Analysis of adenoid hyperplasia and its influencing factors of neonates].

Objective: To explore the characteristics of neonatal adenoid development and to study the relationship between neonatal adenoid development and disease. Methods: A retrospective analysis of neonates who received an electronic rhinopharyngolaryngoscope at Shenzhen Children's Hospital from January 2019 to December 2020 was conducted to track the children's medical history and to analyze the adenoid development status. All 131 neonates successfully completed the electronic laryngoscopy. According to the presence or absence of visible adenoid hyperplasia, they were divided into a hyperplasia group (81 cases, 61.83%) and an un-hyperplasia group (50 cases, 38.17%). Results: Compared with the un-hyperplasia group, the age and birth weight of the adenoid hyperplasia group were larger, and the difference was statistically significant (Z age=-4.634,Z weight=-2.273,all P<0.05), but there was no significant difference in gender and gestational age between the two groups. The number of neonates with rhinitis/sinusitis in the hyperplasia group were significantly more than those in the un-hyperplasia group (62.96% vs 48%). Conclusion: The development of neonatal adenoids is related to daily age, birth weight, but not significantly related to gender and gestational age.

[Management strategies for chronic liver disease-related thrombocytopenia].

Chronic liver disease causes bleeding and coagulation system abnormalities through a variety of mechanisms. Thrombocytopenia is a common complication of chronic liver disease. Patients with chronic liver disease, especially liver cirrhosis, often face more invasive examinations or surgeries, which brings great challenges to clinical diagnosis and treatment. Traditional platelet transfusion is the main clinical intervention. With the approval of thrombopoietin receptor agonists, the current management standards for chronic liver disease-related thrombocytopenia may face changes. This article reviews the current main non-pharmacological and pharmacological interventions for chronic liver disease-related thrombocytopenia, and put forwards the corresponding clinical management improvement strategies based on the efficacy and limitations of these interventions.

Optimization of pyrethroid and repellent on fabrics against Stegomyia albopicta (=Aedes albopictus) using a microencapsulation technique.

A new approach employing a combination of pyrethroid and repellent is proposed to improve the protective efficacy of conventional pyrethroid-treated fabrics against mosquito vectors. In this context, the insecticidal and repellent efficacies of commonly used pyrethroids and repellents were evaluated by cone tests and arm-in-cage tests against Stegomyia albopicta (=Aedes albopictus) (Diptera: Culicidae). At concentrations of LD50 (estimated for pyrethroid) or ED50 (estimated for repellent), respectively, the knock-down effects of the pyrethroids or repellents were further compared. The results obtained indicated that deltamethrin and DEET were relatively more effective and thus these were selected for further study. Synergistic interaction was observed between deltamethrin and DEET at the ratios of 5 : 1, 2 : 1, 1 : 1 and 1 : 2 (but not 1 : 5). An optimal mixing ratio of 7 : 5 was then microencapsulated and adhered to fabrics using a fixing agent. Fabrics impregnated by microencapsulated mixtures gained extended washing durability compared with those treated with a conventional dipping method. Results indicated that this approach represents a promising method for the future impregnation of bednet, curtain and combat uniform materials.

5-Aza-2'-deoxycytidine may influence the proliferation and apoptosis of cervical cancer cells via demethylation in a dose- and time-dependent manner.

The methylation of tumor suppressor genes has been shown to be involved in many human cancers. 5-Aza-2'-deoxycytidine (5-Aza-CdR) can reactivate the expression of methylated tumor suppressor genes. In our study, 2 human cervical cancer cell lines, HeLa and SiHa, were treated with different concentrations (20, 10, 5, and 2.5 µM) of 5-Aza-CdR for 24, 48, and 72 h. After incubation, cells were analyzed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay and flow cytometry. The expression of RASSF1A and APAF-1 was detected by RT-PCR. 5-Aza-CdR inhibited the growth of HeLa and SiHa cells at different concentrations. The strongest inhibition and apoptosis rates were obtained after incubation for 72 h (5.63 ± 1.38 and 8.24 ± 2.40%, respectively). No significant difference in the expression of RASSF1A was found upon drug treatment, while APAF-1 expression increased in HeLa cells after treatment (0.790 ± 0.056%). Our results suggest that the tumor-suppressive effect of 5-Aza-CdR may result from the reactivation of silenced APAF-1 through demethylation.

Protein and mRNA analysis of myosin heavy chains in the developing avian pectoralis major muscle.

While the existence of post-hatch and adult myosin heavy chain isoforms in the large, avian type IIB pectoralis major muscle has been clearly established, the number and nature of fast myosin heavy chains during in ovo development and the perihatch period have not been resolved. In the present study, developmental fast heavy chain proteins purified by high resolution anion-exchange have been characterized by sequence analysis of a unique CNBr peptide and by complementary mRNA analysis. The four proteins present at 15/16 days in ovo are shown to differ uniquely in primary structure. They correlate with heavy chains II, IV, VI and VII, characterized recently as major or minor species in adult fast muscles using similar methods. These four heavy chains are expressed in a time-dependent fashion from 8 to 16 days in ovo. At the mRNA level, heavy chain VI predominates until 12 days in ovo. Heavy chain IV mRNA is upregulated dramatically at 16 days in ovo preparatory to its protein's predominance in the peri-hatch period. Heavy chains II, IV and V (the post-hatch isoform which replaces heavy chain IV) have major roles in adult fast muscles.

Characterization of the myosin heavy chains of avian adult fast muscles at the protein and mRNA levels.

High resolution anion-exchange chromatography of myosin subfragment-1 in avian fast muscles revealed five fast heavy chains (I-V) expressed in muscle-specific patterns. Sequence analysis of a unique peptide established that the proteins differed in primary structure and suggested correlation with heavy chain genes identified independently by Robbins and coworkers. The identities of the isoforms and their expression patterns were confirmed at the mRNA level by a reverse-transcription, 5'-anchored PCR procedure. The fast white pectoralis major muscle possessed heavy chain I, the posterior latissimus dorsi muscle, of similar fibre type, expressed heavy chains I, III and IV. The fast red adductor superficialis muscle expressed either, or both, of heavy chains II and IV. The lateral gastocnemius muscle, of mixed fibre type, expressed heavy chains II-V. In general, heavy chains I, III and V appeared to be favoured in fast white fibres, while heavy chains II and IV were characteristic of fast red fibres. These results imply a greater subtlety of fast muscle function than has previously been appreciated.

Isocitrate dehydrogenase from bovine heart: primary structure of subunit 3/4.

Bovine NAD(+)-dependent isocitrate dehydrogenase was shown previously to contain four subunits of approx. 40 kDa (subunits 1-4) possessing different peptide maps and electrophoretic properties [Rushbrook and Harvey (1978) Biochemistry 17, 5339-5346]. In this study the heterogeneity is confirmed using enzyme purified by updated methods and from single animals, ruling out allelic variability. Subunits 1 and 2 were differentiated from each other and from subunits 3 and 4 by N-terminal amino acid sequencing. Subunits 3 and 4 (subunits 3/4) were identical in sequence over 30 residues. The N-terminal residues of subunits 1 and 2 were homologous but not identical with the beta- and gamma-subunits respectively of the comparable pig heart enzyme. Subunits 3/4 were identical over 30 residues with the N-terminus of the pig heart alpha-subunit. Full-length sequence, including that for mitochondrial import, is presented for a protein with the processed N-terminus of subunits 3/4, deduced from cloned cDNA obtained utilizing the N-terminal sequence information. The derived amino acid sequence for the mature protein contains 339 amino acids and has a molecular mass of 36,685 Da. Complete identity with N-terminal and Cys-containing peptides totalling 92 residues from the alpha-subunit of the pig heart enzyme [Huang and Colman (1990) Biochemistry 29, 8266-8273] suggests that maintenance of a particular three-dimensional structure in this subunit is crucial to the function of the enzyme. An electrophoretic heterogeneity within the pig heart alpha-subunit, similar to that shown by bovine subunits 3/4, was demonstrated. One reordering of the Cys-containing peptides of the pig heart alpha-subunit is indicated. Sequence comparison with the distantly related NADP(+)-dependent enzyme from Escherichia coli, for which the three-dimensional structure is known [Stoddard, Dean and Koshland (1993) Biochemistry 32, 9310-9316] shows strong conservation of residues binding isocitrate, Mg2+ and the NAD+ moiety of NADP+, consistent with a catalytic function.

Developmental myosin heavy chain progression in avian type IIB muscle fibres.

Myosin heavy chain species were investigated during development in avian pectoralis major muscles (type IIB fibres) by high resolution anion-exchange chromatography of the myosin head region, subfragment-1. At 15 days in ovo four distinct fast-type heavy chain species, I, II, III and IV, in order of elution, were identified. By 19 days in ovo, form IV had become predominant and remained the major species through 3-days post-hatch. This form has been named the peri-hatch form. Between 3 and 5 days post-hatch, a second massive change occurred such that by 5 days post-hatch a new species, V, apparent at 19 days in ovo in small amounts, dominated and at 8 days post-hatch was the only heavy chain species present. Form V, which corresponds to that previously identified as the post-hatch form, continued as the major species through 20 days post-hatch and was replaced slowly by the adult form. N-terminal sequencing of CNBr peptides from three subfragment-1 heavy chain species, the peri-hatch (form IV), the post-hatch (form V) and adult, revealed differences in amino acid sequence consistent with the three being products of different genes. These results confirm and extend recent reports of complexity in fast heavy chain expression prior to hatching in the chicken (Hofmann et al., 1988; Van Horn & Crow, 1989).

Variability in the amino terminus of myosin light chain 1.

Three naturally occurring variants of myosin light chain 1, type I, II, and III from avian fast-twitch muscle, have been analyzed by reverse-phase HPLC peptide mapping and amino acid sequencing. Difference peptides were absent from accompanying digests of the related protein, myosin light chain 3, indicating that the heterogeneity was located in the N-terminal 50 residues unique to light chain 1. The type II variant possessed the previous published sequence for the protein [Nabeshima Y., Fujii-Kuriyama, Y., Muramatsu, M., & Ogata, K. (1984) Nature (London) 308, 333-338]. The type I variant, which migrates faster than the type II on SDS gene electrophoresis, contained a Pro----Ala substitution at residue 15, turning the Lys-Pro-(Ala)5(Pro-Ala)7 stretch in this region into Lys-Pro-(Ala)7(Pro-Ala)6. The type III variant, which migrates just faster than the type I, had an (Ala)2 deletion in the (Ala)5 run, yielding Lys-Pro-(Ala)3-(Pro-Ala)7. As indicated by the SDS gel migration rates, the type I and III variants are significantly shorter in length than the type II. The benign nature of the changes is consistent with a flexible arm function for the N-terminal region of light chain 1, with the structural changes in the variants occurring in the spacer region of the arm.(ABSTRACT TRUNCATED AT 250 WORDS)

Complexity of myosin species in the avian posterior latissimus dorsi muscle.

The myosin content of the avian posterior latissimus dorsi muscle, a small fast-twitch muscle similar in fibre type to the much-studied pectoralis major muscle (type IIB), has been explored using high resolution chromatography of the proteolytic fragment known as subfragment-1 and of the products of its limited tryptic digestion, followed by N-terminal sequencing of selected peptides. The complexity of species found greatly exceeds that anticipated from the fibre-type homogeneity of the muscle and from previous studies (Bandman et al., Cell 29 (1982) 645-50; Lowey et al., J. Musc. Res. Cell Motility 4 (1983) 695-716; Crow & Stockdale Dev. Biol. 118 (1986) 333-42). A minimum of four heavy chain species were identified. One form, approximately 40% of the heavy chain complement, appears to be identical to the well-characterized type IIB isoform of the pectoralis major muscle. The remaining species differ from the pectoralis major form in primary sequence. None is identical to the post-hatch isoform of the pectoralis major muscle.