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Biomedical subjects

G Huang

Publications and source records attributed to G Huang.

At least 235 records · Page 13Linked to original sources
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↗
PubMed1990

[Measurement and clinical application of MEFV and PEFV curves in young children].

Previous studies of children's ventilatory functions revealed that a history of pediatric respiratory illness could cause an adult airway to be highly susceptible to the adverse effects of a variety of bronchial stimulants and infectious agents and easy to develop obstructive airway diseases in adult life. Ten indexes of ventilatory function were measured with MEFV and PEFV curves in 333 normal young children aged between 3 and 6, and 15 sick children of bronchopneumonitis in the same age range. Multiple regression equations of different indexes of normal children were set up. The measured values of various indexes of the sick children were much lower than the correspondent predicted values calculated from multiple regression equations, especially VT, VmaxFRC and VmaxFRC/FRC (P less than 0.05). The results suggest that the measurement of PEFV is a convenient and sensitive method to test children's ventilatory function.

Child↗
PubMed1990

[Mean transit time and partial mean transit time of spirogram in 628 normal adolescents].

The mean transit time(MTT) and partial mean transit time(MTTp) were measured and analysed by "direct method" in 628 cases of normal adolescents in Cheng-du. The results showed that both MTT and MTTp were increased with age and prolonged with the decay of lung volume. Besides, the FVC-t curve was not single exponential in nature. The specific mean transit time (SMTT) was introduced by correcting MTT with 0.5 FVC and represented the MTT when unit volume of gas passed through just at that lung volume. SMTT was highly negatively correlated with age. This reflected the development and growth of the lung recoil and airway conductance in adolescents.

Adolescent↗
PubMed1989

Sudan stain of fecal fat: new insight into an old test.

The 72-h fecal fat determination is used as the gold standard to document the presence of steatorrhea. Although the Sudan stain for fecal fat is advocated as a sensitive screening test, a quantitative correlation between the 72-h fecal fat quantitation and the fecal Sudan stain is lacking. This study was designed to examine the staining properties of different classes of purified lipids in an experimentally defined artificial matrix, and to elucidate the reasons for the lack of quantitative correlation between these two tests. Our results indicate that the "neutral fat" stain without acidification or heating identifies triglyceride; and at an appropriate pH, the "neutral stain" also identifies fatty acid. The "split fat" stain with acidification and heating identifies both triglyceride and fatty acid. After acidification, fatty acid soaps are converted to the nonionized fatty acid. Thus, fatty acid soaps can be identified indirectly as fat droplets that are stained by the split fat stain. Although cholesterol is stained with Sudan stain after heating, upon cooling, cholesterol forms crystals of anhydrous cholesterol, making its staining pattern distinct. Neither the neutral fat nor the split fat stain can detect phospholipid or cholesteryl ester. The 72-h fecal fat determination is a measure of the total fatty acid content after a specimen is saponified. The resulting fatty acids are derived from a variety of endogenous and exogenous sources, including free fatty acids, soaps of fatty acids, triglycerides, cholesterol esters, and phospholipids. Therefore, the 72-h fecal fat quantitation does not differentiate between the primary sources of the measured fatty acid. It is concluded that the 72-h fecal fat determination is not specific for documenting triglyceride (fat) malabsorption. Until new methods are developed that specifically measure fecal triglyceride and fatty acid, the Sudan stain of fecal fat appears to be a more specific method for detecting the presence of triglyceride and fatty acid in a matrix.

Azo Compounds↗
PubMed1989

Fecal triglyceride excretion is not excessive in pancreatic insufficiency.

Steatorrhea can result from maldigestion or malabsorption. As the pathophysiology underlying impaired digestion differs from impaired absorption, it is important to differentiate these two disorders. It is generally accepted that patients with maldigestion excrete an excessive amount of triglyceride and patients with malabsorption excrete an excess of the lipolytic product of triglyceride, fatty acid. The two-step Sudan stain has been used as a simple test to differentiate these disorders. The validity of the test has not yet been established. In this study, fecal fatty acid and triglyceride were measured after extraction and thin-layer chromatographic separation. Our results indicate that in adult patients with pancreatic insufficiency, the fecal triglyceride content does not differ from the controls. However, a fivefold to sixfold increase in fecal fatty acid content in patients with pancreatic insufficiency was revealed. As patients with maldigestion do not excrete an excess of undigested triglyceride, it is not possible to differentiate maldigestion from malabsorption by quantifying fecal triglyceride and fatty acid.

Adult↗
PubMed1989

[Differences in length and weight growth patterns between urban and rural infants].

Mixed longitudinal data of length and weight growth from 595 rural and 337 urban infants were analysed. Count models were fitted to the means of length and weight in different ages, sexes and feedings separately. The curve fitting to the data was rather satisfactory. Comparison of model parameters between urban and rural infants suggested that rural infants had a higher length level at birth but lower accelerative growth afterwards than urban ones, which was even more obvious in breast-fed infants. The difference in birth weight between them was not significant; and the urban infants had a faster linear growth velocity than rural ones. These results might be caused by the fact that food supplementing in urban infants was significantly earlier and better than in rural ones.

Body Height↗
PubMed1989

The pancreas and oxygen consumption (Part 2). Steroids do not modify resting pancreatic oxygen consumption in dogs: a preliminary report.

In order to evaluate the effect of methylprednisolone sodium succinate (MPSS) on the alteration of pancreatic oxygen consumption (VO2) in hypovolemic shock, MPSS was administered to four normal canines and three hypovolemic animals. All were treated according to the protocol used in the initial report. (The Pancreas and Oxygen Consumption 1: Pancreatic Oxygen Consumption in Normo- and Hypovolemic Dogs.) All seven underwent a splenectomy at the beginning of the experiment. Pancreatic VO2, obtained by adding up VO2 for the head (minus the uncinate process) and tail of the pancreas, was equal to the product of regional blood flow, Q, determined electromagnetically on the gastroduodenal (GDA) and splenic (SA) arteries, times O2 extraction, (a-v)O2; O2 content (in mL%) was measured in the femoral artery (RFA), in the splenic (SV) and superior pancreaticoduodenal (SPDV) veins. Similar determinations were carried out on the right hind limb that served as a control. Recordings were made for 4 h in both groups, the first hour determinations (five in all) serving as reference values. Methylprednisolone did not appear to alter pancreatic VO2, which showed a significant increasing trend from + 77% 1 h after MPSS had been given, to + 98% 3 h later (vs + 56 and + 92%, respectively, in the control group). As in the control group, these increases were owing to augmented O2 extraction by the pancreas. No significant change was noted between the head and tail of the pancreas. In the hind limb, VO2 increased significantly the first 2 h and differed from control VO2 at the end of the first hour only.

Animals↗
PubMed1989

Halogenation and anesthetic potency.

Previous studies have shown that the anesthetic potency of organic compounds increases as a given halogen is replaced with successively larger halogens. These studies often are limited in the accuracy of determination of potency, rarely correlate potency with physical properties, and usually fail to include ether compounds. Because establishing relationships between structure and activity may shed light on anesthetic action, we studied the new anesthetic, I-537 (CHF2-O-CHBr-CF3), relative to two other ether anesthetics, I-653 (CHF2-O-CHF-CF3) and isoflurane (CHF2-O-CHCl-CF3) for both of which MAC and oil/gas partition coefficients are accurately known. The oil/gas partition coefficient of I-537 at 37 degrees C was found to be 245 +/- 6 (mean +/- SD) and the MAC in Sprague-Dawley rats 0.52 +/- 0.07%. Increasing atomic weight of the 1-ethyl halogen (i.e., F in I-653, Cl in isoflurane, and Br in I-537) progressively decreases MAC (increases potency) and increases lipid solubility. Although potency and solubility change by more than 10-fold, the product of MAC and the oil/gas partition coefficient remains essentially constant (120 +/- 11). However, this product is significantly less than that for other inhaled anesthetics, a finding which either challenges the unitary theory of narcosis or suggests that the lipid solvent classically used to model the site of anesthetic action (olive oil) is inappropriate.

Anesthetics↗
PubMed1989

The pancreas and oxygen consumption. 1. Pancreatic oxygen consumption in normo- and hypovolemic dogs.

Pancreatic oxygen consumption (VO2) was studied in hypovolemic shock: 4 dogs served as controls and 4 others were kept at 50 mm Hg of mean arterial blood pressure. All 8 were studied for a period of 3 h. Pancreatic VO2 was obtained by adding up VO2 for the head (minus the uncinate process) and tail of the pancreas both equal to the product of regional blood flow times O2 extraction. Regional blood flows were measured electromagnetically on the gastroduodenal (GDA) and the splenic (SA) arteries, whereas O2 extraction was derived from total hemoglobin (THb) and oxygen saturation of hemoglobin (%O2 Hb) determined on the right femoral artery (RFA), the superior pancreaticoduodenal (SPDV), and splenic (SV) veins. A splenectomy was performed in all 8 dogs. Controls showed a significantly elevated pancreatic VO2 from the first hour of observation on (+56% after 1 h, +92% after 3), whereas pancreatic VO2 remained strictly unchanged throughout shock (+2% and +6%, at one and 3 h, respectively), despite significant increases in O2 extraction. These findings give support to the deleterious effects of hypovolemia to the pancreas and that pancreatic O2 extraction indicates metabolic damage to be less severe than observed in experimental bile-trypsin-induced acute pancreatitis.

Acute Disease↗