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G Huang

Publications and source records attributed to G Huang.

At least 19 recordsLinked to original sources
PubMed2026

Sulfated mannan of diatoms selects host-specific microbiota in the sunlit ocean.

BACKGROUND: Diatoms, a keystone phylum in Earth's ecosystems, are responsible for substantial oxygen production and the fixation of carbon dioxide in the form of carbohydrates that fuel global food webs. They host diverse prokaryotes, yet how diatoms preferentially recruit those with complementary metabolic traits remains unknown. RESULTS: We discovered that diatoms exude a C6-sulfated α-1,3-mannan that serves as a selective carbon source for adapted Polaribacter. Its structure was resolved using NMR spectroscopy, chromatography, chemical synthesis, and enzymatic dissection. Biochemical, physiological, and structural analyses demonstrated, that specialized Bacteroidota employ a four-enzyme pathway to metabolize this glycan. Metagenomic and transcriptomic data revealed that sulfated mannan utilization loci are globally abundant and actively expressed in surface ocean bacterioplankton. Because this mannan provides only carbon, oxygen, sulfur, and hydrogen, bacteria must obtain other essential elements elsewhere, reinforcing metabolic interdependence. CONCLUSIONS: Together, these results define a chemically specific interaction between diatoms and specialized bacteria that is mediated by a single sulfated polysaccharide and a dedicated four-enzyme degradation pathway. Presence of this pathway in marine metagenomes and transcriptomes indicates that a sulfated mannan from diatoms exerts selection pressure in the sunlit ocean microbiome. Video Abstract.

Diatoms↗
PubMed1992

A pathological study of sudden coronary death in China: report of 89 autopsy cases.

This paper reports the results of a forensic pathological study of 89 autopsy cases of Sudden Coronary Death (SCD). Of 89 cases, 63 (52 male, 11 female) were narrowed by 76-100% in cross-sectional area (XSA) of the coronary artery (CA) and 26 (22 male, 4 female), by 51-75%. Atherosclerotic plaques in the CA were serious and extensive, especially in the left anterior descending and often involved several branches of CA at the same time. Recent thrombosis was found in 18 cases, haemorrhage in plaques in 17 cases. Only 2 cases had visible acute myocardial infarction. Inflammatory cell infiltration was found in coronary plaques in 36 cases. Myocardial fibrosis or small scar formation was detected in 51 cases. It is suggested that although the incidence of coronary heart disease (CHD) is low in China, SCD is the commonest mode of Sudden Unexpected Death. The majority of SCD (52%) were middle aged males (30-49 years old). Most of the cases died suddenly during sleep without any clear precipitating factors. The characteristics of occurrence and pathological changes in the CA and myocardium and the pathological diagnosis of SCD are also analysed and discussed.

Adult↗
PubMed1992

Failure of dengue viruses to replicate in Culex quinquefasciatus (Diptera: Culicidae).

Culex quinquefasciatus (Say) and Aedes aegypti (L.) were parenterally infected with dengue viruses and virus replication was monitored at intervals after infection in each species. Dengue viruses replicated rapidly in Ae. aegypti, reaching a peak titer of 10(6)-10(7) mosquito infectious dose 50 (MID50) per mosquito. In Cx. quinquefasciatus, however, dengue virus replication did not occur. We conclude that this mosquito species is refractory to infection with dengue viruses and, therefore, does not serve as a vector in nature.

Aedes↗
PubMed1992

Studies on the luminescence of channels in rats and its law of changes with "syndromes" and treatment of acupuncture and moxibustion.

We previously reported the discovery of 14 channels in the human body, which possessed the biophysical property of high emission of light. In this study we found the same property on the Ren and Du channels in healthy rats. Additionally, we discovered that the luminance of the related channels in rat models with different "syndromes" varied greatly. For instance, a markedly low luminance appeared on the Du channel in animals with experimental syndrome of Yang deficiency induced by hydrocortisone; while in animals with experimental syndrome of blood deficiency caused by bleeding, an apparently low luminance occurred on the Ren channel. The intensity of the emitted light on Du and Ren channels increased after acupuncture treatment, but not significantly. This phenomenon conforms to the theory in traditional Chinese medicine that the Du channel is the "sea of Yang channels", while the Ren channel is the "sea of Yin channels".

Acupuncture Therapy↗
PubMed1992

[Experimental reconstruction on intrinsic hand muscle function by anterior interosseous nerve transference].

The anterior interosseous nerve was transferred to the recurrent branch of the median nerve and the deep branch of the ulnar nerve respectively to restore the function of the intrinsic hand muscles. Twelve Rhesus monkeys were used with 24 nerves for transference and 24 for direct suturing. Gross, histological, and ultrastructural observations, electrophysiological evaluation and computer-imaging analysis system were employed to assess the nerve regeneration process in 1,3,6, and 12 months after operation. The results showed that the rate of maturity and the number of regenerating nerves in the distal segment approached the normal level and the passing rate of the myelinated axons reached to 156.16 +/- 14.45% 12 months after operation. According to the histological findings and the recovery of the intrinsic hand muscle function, reinnervation in the transferred nerves occurred 1 to 3 months earlier than that in the directly sutured ones.

Animals↗
PubMed1992

[Technique of measuring esophageal pressure in rabbits and its application to measurement of pulmonary compliance and resistance].

Esophageal pressure (Pes) was measured under non-invasive condition by an esophageal balloon made by ourselves, and the optimal position of rabbits for measuring Pes was explored. The correspondence between Pes and pleural pressure (Ppl) was examined in rabbits during different depths of breathing with varied lengths of balloon and varied depths of insertion of balloon into the esophagus. The results showed that the amplitude of Pes only on supine position was higher than that on the left and right lateral and prone positions, but no significant difference was noticed among the 3 positions. The optimal balloon length was 4-6 cm. The optimal depth of insertion of balloon into the esophagus was 20 cm. The pulmonary dynamic compliance and pulmonary resistance were measured in 11 white rabbits with 5 cm balloon, 20 cm depth of insertion, on the left lateral position. The results were correspondent with other authors. No significant difference was noticed in repeated measurements on 8 of the 11 rabbits 5 days later.

Airway Resistance↗
PubMed1992

[A preliminary study of the chord and specific time constants in 342 healthy children].

Using Knudson's method, the chord time constant, tau ch, tau ch75, tau ch50, tau ch25, and specific time constant, S tau, 1/V75, 1/V50, 1/V25, at high, middle and low lung volumes were calculated from V75, V50 and V25 of the MEFV curves measured previously from 342 healthy children of 3-6 years of age in a nursery. The multiple stepwise regression equation were built with age, height and FVC as independent variables by the IBM-XT/PC computer. The result showed that the S tau corrected by volume from tau ch could reflect the time required for change of unit lung volume more precisely than tau ch owing to the elimination of the influence of lung volume. The S tau was shortened with the increase of age, and was negatively correlate with age and FVC. These facts reflected the growth of lung elastic pressure (PLel) and airway conductance (Gaw) with the increase of age. The prolongation of S tau with the decay of lung volume just reflected the decrease of PLel and Gaw with the decay of lung volume. No regular changes of tau h were observed with age and lung volume. Probably, it was concerned with the complexity of factors affecting the tau ch.

Airway Resistance↗
PubMed1992

[Clinical significance on expression of the ras gene product P21 in human cervical carcinoma tissues].

Using MAB-P21 as a probe, the expression of gene product was studied by immunohistochemical ABC method, ABC staining of gel electrophoresis and ELISA quantitative analysis. The expression of P21 was detected in 107 cases of uterine cervix tissues, among which 70 were cervical carcinoma, 30 were chronic cervicitis and 7 normal cervix. Experimental results showed that obviously positive expression was noted in the specimens of cervical carcinoma and its positive rate was 72.8% (51/70). It was observed that the expression of P21 varied with grades of cell differentiation in cervical carcinoma. The level of P21 expression in high differentiated type was higher than that of the middle and low differentiated types. On the contrary, there was no detectable ras P21 in the normal cervix tissue and only 2 cases of cervicitis expressed positively (2/30). The results of ABC staining of electrophoresis showed that there was a P21 special staining band in cervical carcinoma tissues. And the contents of P21 protein were higher in cervical carcinoma than in normal cervix and cervicitis (t test, P less than 0.001). The expression of P21 was considerably enhanced in malignant tissue as compared with that in benign lesion.

Adenocarcinoma↗
PubMed1992

[The purification and properties of LD5 from normal C57 mouse liver, H22 hepatoma and S180 sarcoma].

Type-A LDH (LD5), isolated from normal C57 mouse liver, H22 hepatoma and S180 sarcoma after a sequential ion-exchange and affinity chromatography, was examined to be quite pure. Studies on the enzyme kinetics and immunological properties showed that there were no differences in optimal pH, optimal temperature, subunit MW., isoelectric point between normal and malignant (H22 hepatoma and S180 sarcoma) LD5. Km to pyruvate decreased in malignant LD5 while LD5 content and percentage increased. Three LD5 antibodies raised against rabbits showed cross-reaction. These antibodies as probes are useful in the isolation of LD5-mRNAs from G57 mouse liver H22 hepatoma and S180 sarcoma.

Animals↗
PubMed1991

[The status of human papillomavirus 16 DNA in the tissues of human esophagus carcinoma].

DNAs from 24 cases of human esophagus carcinoma and 24 cases of corresponding para-carcinoma tissues were detected by dot hybridization and Southern hybridization techniques using human papillomavirus (HPV) 16 type DNA as probe. The results indicated that the positive rate of the HPV 16 DNA hybridization was 50% (12/24) in esophagus carcinoma tissues, and 37% (9/24) in para-carcinoma tissues. The results of Southern hybridization showed obviously the positive hybridizing band in the zone of 7.2 kb in smear. It implied that HPV 16 DNA was possibly integrated into the tissue's DNA of esophagus carcinoma. In the fetal esophagus tissues as negative control, 3 cases out of 4 showed positive results. The significance has to be further investigated. This experiment has studied the status of HPV 16 type in the tissues of esophagus carcinoma and para-carcinoma at molecular level. This is just a study of the virus etiology of esophagus carcinoma.

Blotting, Southern↗
PubMed1991

[Relation between the dosage of methimazole and its intrathyroidal concentrations].

Intrathyroidal concentrations of methimazole (MMI) were measured by means of high-performance liquid chromatography in 46 patients with Graves' disease who had undergone thyroidectomy. In this experiment, the dose of the drug varied from 5 mg/day to 40 mg/day, and the interval between the last dose and surgery ranged from 2 to 26 hours, and the mode of drug administration varied from a single dose to four divided doses. With dose of MMI from 5 to 15 mg/day, intrathyroid levels of MMI increased with increasing dose, but without significant increase when the dose was above 15 mg/day. There was no difference between patients taking the drug in divided doses and those taking it in one single dose of the same amount, or between patients taking the final dose 2 hours before thyroid excision aud those taking it 26 hours before excision. Our results indicate a saturable uptake mechanism for MMI by the thyroid, and MMI 15 mg/day is the most satisfactory dose for treating hyperthyroidism. The intrathyroidal concentrations are maintained for 26 hours at least, and the single daily dose of MMI is effective and reasonable for treatment of Graves' disease.

Adolescent↗
PubMed1991

[Effect of air pollution in MTTp (convenient calculation) of children].

A convenient formula (MTTp = 0.1FVC/2Vp) was derived according to the linear character of each 10% FVC portion on the FVC-t curve proposed by Jordanoglou. It was used to examine 765 healthy school children at the age of 8-13 in the lightly and heavily polluted, and controlled areas in the living quarters in a steel corporation. The results showed that the small airways were more severely affected than the larger ones. MTT45-55% at the middle lung volume had both higher sensitivity and accuracy, and could be considered as a good index for tests on the function of small airways in air pollution while MTT20-30% and MTT70-80% at high and low lung volumes had greater variability and less accuracy.

Air Pollutants↗
PubMed1991

[Determination of the partial mean transit time with "convenient calculation" in young children].

A "convenient calculation" of MTTp = 0.1 FVC/2 Vp was derived from the principle of Jordanoglou to measure the partial mean transit time (MTTp). It was used to calculate the MTTp from the maximal expiratory flow volume (MEFV) curve of 342 healthy young children. The multiple regression equations were built with age, height and FVC as independent variables. The result showed that the MTTp of all children were elongated with the decay of lung volume with a similar rule as in the old, middle-aged and young people. No regular changes of MTTp in age groups were noticed. The regression equations showed that the MTTp of boys were positively correlated with FVC; while those of girls were negatively correlated with age; besides, MTT20-30% and MTT70-80% were positively correlated with FVC. The age and FVC just had the opposite effects so that little regular changes of MTTp occurred in the age groups.

Child↗
PubMed1990

Transcriptional analysis of the promoter region of the Pseudomonas putida branched-chain keto acid dehydrogenase operon.

Branched-chain keto acid dehydrogenase is a multienzyme complex produced by Pseudomonas putida when it is grown in a minimal medium containing branched-chain amino acids. A 1.87-kilobase (kb) DNA fragment was cloned and sequenced which contained 0.24 kb of the E1 alpha structural gene and 1.6 kb of upstream DNA. There were 854 base pairs (bp) of noncoding DNA upstream of bkdA1, the first gene of the bkd operon, and 592 bp between the transcriptional and translational starts. The G + C content of the noncoding region was 56.7% compared with 65.2% for all the structural genes of the operon. A partial open reading frame was found on the strand opposite that of the bkd operon beginning at base 774. When the bkd promoter was cloned into the promoter probe vector pKT240, streptomycin resistance was obtained in P. putida but not Escherichia coli with the promoter in both orientations, which indicates either that the bkd promoter is bidirectional or that there are two promoters in this region. A series of ordered deletions on both sides of the proposed site of the start of transcription revealed that almost 700 bp upstream of the start of translation were required for expression. Streptomycin resistance was also obtained in an rpoN mutant of P. putida KT2440 containing constructs with the intact bkd promoter, indicating that the bkd operon does not require the rpoN sigma factor for expression. Another construct containing the bkd promoter, bkdA1, and bkdA2 in pKT240 was used to transform P. putida JS113, a mutant which was unable to produce the E1 subunits of the branched-chain keto acid dehydrogenase. In this case, very high inducible expression of the bkd operon was obtained.

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗
PubMed1990

[Determination of MMTp in 628 normal children and adolescents with "convenient calculation"].

According to the principle of linear character of each 10% FVC segment on the FVC-t curve proposed by Jordanoglou, the slope of each segment is nearly equal to 0.1 FVC/2 MMTp. Then MTTp approximately 0.1 FVC/2Vp. The calculations of MTTp at high, middle and low lung volumes are MTT20-30% = 0.1 FVC/2V75, MTT45-55% = 0.1 FVC/2V50, and MTT70-80% = 0.1 FVC/2 V25. The MTTp of 628 cases of normal children and adolescents aged 6-19 yr. was measured by this method. In comparison with the direct method, the results showed that there was no significant difference between the 2 methods. The regression equations built with age as an independent variable showed a good correlation. Obviously, this method is easily performed, and is suitable for the wide use of MTTp.

Adolescent↗