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Biomedical subjects

D Liang

Publications and source records attributed to D Liang.

At least 91 records · Page 5Linked to original sources
PubMed1995

[A multiple center clinical trial on fluconazole for deep-seated fungal infections].

A multiple center clinical trial was conducted to evaluate the efficacy and safety of domestic fluconazole in treating 913 cases of deep-seated fungal infections. Fluconazole was given 100-200 mg daily for 3 days to 8 months. The results showed that the cure rate and the total efficacy rate were 69.26% and 94.29% respectively. The fungal clearance rate was 93.83%. The main side-effects were nausea, vomiting, diarrhea and abdominal pain, but most of the patients could endure. The side-effect rate was 9.20%. This clinical trial indicated that domestic fluconazole was effective and safe in treating deep-seated fungal infections.

Adolescent↗
PubMed1995

[The relations of corneal, lenticular and total astigmatism].

PURPOSE: To determine the relations of corneal, lenticular and total astigmatism and the changes of the astigmatism with age. METHOD: Out-patients with refractive errors were refracted with retinoscope after using cycloplegic drops and measured the radii of anterior corneal curvature. RESULT: One hundred and ninety-four cases (382 eyes) with refractive errors were studied. Of the eyes 67.9% had regular corneal astigmatism, 68.1% irregular lenticular astigmatism and 60.7% regular total astigmatism, 88.5% of the corneal astigmatism has the same quality as the total astigmatism. The total astigmatism in 46% of the eyes included the summation of corneal and lenticular astigmatism, but in 41.3% of the eyes irregular lenticular astigmatism corrected the regular corneal astigmatism. The astigmatism of cornea, lens and total astigmatism changed from regular to irregular with the increase of age. The linear correlation analysis showed a positive correlation between the power of horizontal corneal refraction and age, and a negative corrlation between the power of vertical corneal refraction and age. CONCLUSION: The shape of cornea was the major cause of total astigmatism. The influence of lens on the total astigmatism was different. The reasons for the change of the total astigmatism from regular to irregular with the increase of age were the changes of the power of corneal refraction, particularly the increase of the power of horizontal corneal refraction and lenticular irregular astigmatism.

Adolescent↗
PubMed1994

High-performance liquid chromatographic assay of cefazolin in rat tissues.

A rapid, sensitive and reproducible high-performance liquid chromatographic (HPLC) assay for cefazolin in rat tissues was developed. Tissue samples were homogenized in distilled water, acidified with 8.5% phosphoric acid, and centrifuged. Cefazolin was isolated from the supernatant by solid-phase extraction on C18 cartridges. The eluate containing cefazolin and internal standard, cephalexin, was injected onto a reversed-phase C18 column and eluted with a mobile phase of 23% methanol in 0.02 M sodium phosphate monobasic (pH 5.0) and detected with UV absorbance at 270 nm. Recoveries of cefazolin were 33.7 +/- 2.5%, 45.4 +/- 2.1%, and 42.9 +/- 1.0% from liver, spleen and lung, respectively. The calibration curves for cefazolin were established at 0.5-1500 micrograms/g in spleen, 0.1-250 micrograms/g in liver and 0.1-75 micrograms/g in lung. The assay was reproducible with within-day and between-day variations of 1-2 and 1-4%, respectively. Application of the assay for tissue distribution of cefazolin in liposomal targeting study was demonstrated.

Animals↗
PubMed1994

Use of the four-and-a-half clearing technique to study gymnosperm embryology: Cunninghamia lanceolata.

Since its introduction in 1971, the four-and-a-half clearing technique has been widely applied to the study of ovule and female gametophyte development in flowering plants as an alternative to the more arduous paraffin section methods. The technique has undergone several modifications that have broadened its application in studies of Angiosperm embryology. To date, however, the technique has not been successfully applied to embryological features of Gymnosperms. Dark coloration caused by naturally occurring substances and by-products of fixation render the clearing fluid ineffective, and special pretreatment methods used to remove dark substances in Angiosperm ovules have little or no effect on Gymnosperm material. In the technique reported here, paraffin sections of ovules and young seeds of Cunninghamia lanceolata 80-120 microns thick are cleared in benzyl benzoate-4 1/2 clearing fluid and examined with phase contrast optics. Observations of the mature female gametophyte in these cleared preparations are compared with those obtained from 10 microns sections, stained with safranin and fast green, and examined with bright-field optics. Although contrast and definition are more pronounced in stained sections than in cleared ones, the differences would not alter one's interpretation of characteristic structural features. The thick, cleared section offers an advantage over the thin, stained one in that many structural entities are contained within a single section rather than spread through several serial sections. The time required for clearing thick sections is much shorter than that required for making permanent stained preparations.

Microscopy↗
PubMed1993

Sex pheromone for the brownbanded cockroach is an unusual dialkyl-substituted alpha-pyrone.

Female brownbanded cockroaches, Supella longipalpa, emit a sex pheromone that attracts males from a distance. This pheromone was isolated and identified as 5-(2,4-dimethylheptanyl)-3-methyl-2H-pyran-2-one (which we refer to as supellapyrone), and its structure was confirmed by synthesis. A racemic blend of the synthetic compound elicited behavioral and electrophysiological responses comparable to the natural pheromone across a range of doses. This compound is not only a very different type of cockroach pheromone but also makes up an additional class of natural products--namely, 3,5-dialkyl-substituted alpha-pyrones.

Journal Article↗
PubMed1993

[Study on the relationship between appearance of autoantibodies and chest X-ray findings of asbestos plant employees].

Antinuclear factor (ANA) and rheumatoid factor (RF) were determined in 220 employees of an asbestos plant. The relationship of the appearance of the two factors to sex, age, smoking habit, duration of asbestos exposure and asbestos exposure level was studied. In 207 employees who had chest roentgenograms, the relationship of these two factors to pulmonary lesions and pleural lesions was examined. Of the 220 employees, 33 (15%) had ANA and 7 employees (3.2%) had RF. ANA positive rate in the asbestos plant employees was significantly higher than in the control. Factors significantly correlated to their appearance could not be demonstrated. With the progress of pulmonary lesions the ANA positive rate significantly elevated, but ANA positive rate was not significantly correlated with pleural lesions. RF did not show any significant correlation with any of the factors.

Adult↗
PubMed1993

[Experimental observation on the relation between pericardium meridian and cardiac function].

The theory of Traditional Chinese Medicine (TCM) holds that "internally, meridians connect with the visceral organs, and externally, with the joints, limbs and other superficial tissues of the body". The results of the investigations on the meridian phenomena, including propagated sensation along meridians (PSM) and others, also showed that certain lines or tracks, coincident with the course of classical meridians, really existed over the body surface. In order to probe into the relation between the pericardium meridian, acting as a organic whole, and the cardiac function, 100 cases of patients suffering from coronary heart disease, with or without PSM, were observed on the one and the same subject before and after acupuncture for comparison. Four acupoints, namely Neiguan (PC6), Ximen (PC4), Quze (PC3), Tianquan (PC2) and two other non-acupoint spots on the Pericerdium Meridian of the same person were acupunctured in different days respectively. At the same time, the spots locating on the both sides of above 4 acupoints, with a distance of 1.5-2.0 cm from them former, and Guangming (GB37) of Gall-Bladder Meridian were taken as controls. Electrocardiogram, cardiophonogram and rheocardiogram were recorded simultaneously. Taking PEP, LVET, P/L, HI, SV, CO, ST segment and T wave of ECG as indexes for analysis, the effect of acupuncture of acupoints on Pericardium Meridian and controls were compared. The results of 737 times of observation demonstrated that the 8 indexes of 4 acupoints and other two non-acupoint spots on the Pericardium Meridian all changed conspicuously after acupuncture. However, the changes of above indexes of the controls, including 8 spots beside Pericardium Meridian, were slight.(ABSTRACT TRUNCATED AT 250 WORDS)

Acupuncture Points↗
PubMed1993

[The difference in the time for the appearance of acupuncture effects between the subjects with and without PSM during acupuncture of neiguan].

It has been reported that ECG of the patients of coronary heart disease with PSM got marked improvement when Neiguan (PC6) was punctured, in comparison with the patients without propagated sensation along meridians (PSM). The difference between the two was significant. However some others reported that the acupuncture effects between the two had no striking difference. Authors detected that during acupuncture of Neiguan the change of ECG of the patients showed dynamic character and some patients without PSM were also marked as the duration of acupuncture was prolonged. For this reason, this paper was aimed to observe whether any difference appeared in the development of acupuncture effects between the patients with and without PSM. One hundred and seventy cases of patients with coronary heart disease were observed, of which 86 were male and 84 female, aged 35-83 years. Varying degree of PSM appeared in 80 of them, but not in the remaining 90. ECG was recorded with polygraph (model SJ-42) before acupuncture. Then the Neiguan acupoint of the left forearm was punctured by slow twisting for 5 minutes and the feature of PSM was carefully observed. Another recording of ECG was taken after retaining needle for 10 minutes. Retaining needle lasted for 30 minutes in a part of the patients and the needle was manipulated every 16 minutes in order to keep the needling sensation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acupuncture Therapy↗
PubMed1993

Parallel decrease of Na(+)-taurocholate cotransport and its encoding mRNA in primary cultures of rat hepatocytes.

We investigated the molecular mechanism underlying the progressive loss of Na(+)-dependent bile salt uptake in primary cultured rat hepatocytes. A specific cDNA probe was used to quantitate the levels of mRNA encoding the Na(+)-taurocholate-cotransporting polypeptide at various culture times. Hepatocytes were cultured on collagen in the presence of insulin (10(-7) mol/L), dexamethasone (10(-7) mol/L) and 10% fetal calf serum for up to 72 hr. During this time period the dissociation constant of Na(+)-dependent taurocholate uptake remained stable (19 to 39 mumol/L), whereas the maximum velocity values decreased from 100% at 3 hr to 55%, 22% and 4% at 24, 48 and 72 hr, respectively. Concomitantly the levels of the Na(+)-taurocholate-cotransporting polypeptide mRNA also decreased from 100% at 3 hr to 41%, 24% and 4% at the later time points. In contrast, Northern hybridization with complementary DNA probes for three common housekeeping gene products revealed a 1.8- to 3.4-fold increase in the levels of mRNA encoding the alpha-subunit of the Na+K(+)-ATPase, beta-actin and glycerol-3-phosphate dehydrogenase. These data indicate that the loss of Na(+)-dependent bile salt uptake in primary cultures of rat hepatocytes is caused by decreased levels of its specific mRNA. Hence the studies further confirm that without specific measures (primary) cultured rat hepatocytes reverse their liver-specific phenotype to a more fetal pattern of gene expression.

Animals↗
PubMed1993

[Pharmacokinetics of ciprofloxacin in young healthy volunteers].

Pharmacokinetic studies on ciprofloxacin were carried out in 6 young healthy volunteers. Serum and urine levels of ciprofloxacin were measured by reversed-phase high performance liquid chromatography. The drug obeyed one-compartment model kinetics in serum. The mean peak serum concentration, time to peak concentration and the area under the curve were 4.17 +/- 1.05mg/L, 1.75 +/- 0.40h and 18.09 +/- 2.69mg/L.h respectively after oral administration of 500mg of ciprofloxacin tablet. The elimination half life was 2.34 +/- 0.81h and the apparent volume of distribution was 3.71 +/- 0.75L. The urinary rate of ciprofloxacin over 24h after dosing was 34.22 +/- 6.57%. These data indicate that ciprofloxacin is easily absorbed and its concentration reaches the peak level rapidly. There are high levels of drug both in serum and urine.

Adult↗
PubMed1993

[Effect of verapamil with renal disease basic-prescription on hemorheology indexes of type II nephrotic syndrome].

24 cases of type II nephrotic syndrome were studied and divided randomly into two groups. Group A: 12 cases treated with verapamil; Group B: 12 cases treated with verapamil plus Renal Disease Basic-prescription (RDBP). Hemorheology indexes were measured in the two groups before and 4 weeks after the treatment. The results showed hyperviscosity was obviously improved in group A after verapamil administration (P < 0.05), but the improvement in group B was much more significant than that in group A. The results mentioned above indicate that calcium channel blocker has an anticoagulant effect with inhibiting platelet aggregation, and Peach kernel, Safflower, etc of RDBP played a role in prohibiting platelets aggregation, anticoagulation and promoting microcirculation. However the combination of the two methods has better effect in improving the hypercoagulable state of nephrotic syndrome.

Adolescent↗
PubMed1993

[Determination of ciprofloxacin in human serum and urine by reversed-phase HPLC].

A sensitive and rapid method for the determination of ciprofloxacin using enoxacin as the internal standard was reported. High-performance liquid chromatograph model 344 (Beckman, USA) with a variable wavelength UV detector and reversed-phase Ultrasphere-ODS column (5 microns, 250 x 4.6 mm) was used. Serum or urine sample preparation involved addition phosphate buffer (pH 7.5) and aqueous solution of sodium lauryl sulfate, followed by chloroform extraction. The organic layer was removed and evaporated to dryness under an air stream in a 37 degrees C water bath. The residue was dissolved in 50 microliters mobile phase and 20 microliters injected. The mobile phase of 0.02 mol/L acetate buffer (pH 3.0) -acetonitril-dimethylformamide-10% aqueous solution of tetrabutyl ammonium hydroxide (88:6.5:5:0.5) was pumped at 0.9 ml/min through the column. The detector operated at 0.01 aufs and the wavelength was set at 276 nm. The retention times for ciprofloxacin and enoxacin were 7.31 min and 5.59 min, respectively. In serum, standard curve was linear in the concentration range of 0.75 to 24 mumol/L, the detective limit was 0.2 mumol/L, extraction recovery was 69-74%, within-day CV was less than 5%, and inter-day CV was less than 6%.

Chromatography, High Pressure Liquid↗
PubMed1993

Mitochondrial dysfunction in alcoholic patients as assessed by breath analysis.

Mitochondria of patients with alcoholic liver disease are morphologically abnormal, and mitochondria isolated from animals exposed to ethanol exhibit functional deficiencies in vitro. Because the functional consequences of the morphological alterations and the relevance of in vitro observations to mitochondrial function in alcoholic subjects are not clear, we assessed mitochondrial function noninvasively with a breath test. Mitochondrial function was assessed by measuring the exhalation of 14CO2 after administration of 1 microCi 2-keto[1-14C]isocaproic acid, the decarboxylation of which occurs in mitochondria. The results of the 2-keto[1-14C]isocaproic acid breath test in 17 alcoholic subjects were compared with the results in healthy controls and patients with nonalcoholic liver disease. The peak exhalation of 14CO2 and the fraction of the administered dose decarboxylated in 60 min were significantly lower in alcoholic patients than in healthy controls or patients with nonalcoholic liver disease. In alcoholic patients 2-keto[1-14C]isocaproic acid decarboxylation was impaired in the presence of normal conventional and quantitative liver function as assessed by aminopyrine breath test and galactose elimination capacity, indicating that 2-keto[1-14C]isocaproic acid decarboxylation does not simply reflect decreased functional liver mass. We conclude that mitochondrial function as reflected by 2-keto[1-14C]isocaproic acid decarboxylation is impaired in chronic alcoholic patients. The functional impairment is specific for excessive ethanol consumption and not a reflection of decreased global liver function or the presence of cirrhosis. 2-Keto[1-14C]isocaproic acid decarboxylation could thus be useful as a marker of excessive ethanol consumption.

Adult↗
PubMed1992

Protective effects of the calcium antagonists diltiazem and TA3090 against hepatic injury due to hypoxia.

Recent work has shown that dihydropyridine-type calcium channel blockers such as nitrendipine protect against ischemic liver damage in the rat in vivo (Thurman RG, Apel E and Lemasters JJ, J Cardiovasc Pharmacol 12: S113-S116, 1988), suggesting that calcium antagonists may have clinical value in preventing ischemic and hypoxic hepatic injury. This study was designed to examine the effects of two benzothiazepine-type calcium channel blockers, diltiazem and TA3090, in the hypoxic perfused rat liver. Livers were isolated and perfused briefly with oxygen-saturated buffer, followed by perfusion for 80 min with nitrogen-saturated buffer with diltiazem or TA3090 (20-200 microM), and concluding with 20 min of perfusion with oxygen-saturated buffer. In control preparations, maximal lactate dehydrogenase (LDH) release into effluent perfusate following hypoxia averaged about 1100 U/L. Diltiazem and TA3090 decreased LDH release at all concentrations studied; both drugs were most effective at the 100 microM concentration (71 and 73% inhibition, respectively). Oxygen uptake by control livers decreased 78% following hypoxia; diltiazem and TA3090 reduced this effect markedly, with maximal effectiveness again observed with 100 microM (O2 uptake was decreased by 22% with 100 microM diltiazem and by only 9% with 100 microM TA3090). Histological examination for nuclear uptake of the vital dye trypan blue revealed necrosis of parenchymal cells along with cell shrinking and consequent expansion of the sinusoids in control livers. Perfusion with diltiazem markedly reduced parenchymal cell death but did not alter the pattern of cell damage observed. In contrast, livers perfused with TA3090 during hypoxia had virtually no parenchymal cell damage, although moderate damage to nonparenchymal cells in the sinusoids occurred. The difference in mechanisms responsible for the phenomena which occur with diltiazem and TA3090 is not completely understood; however, these and other calcium antagonists clearly have powerful hepatoprotective effects against ischemia and hypoxia.

Animals↗
PubMed1992

[Effects of adrenergic agonist on population spike in CA1 region of hippocampal slices from partial and full kindled rats].

Effects of adrenergic agonist on population spike (PS) amplitude were studied extracellularly at CA1 region of hippocampal slices from partial and full kindled rats with coriaria lactone (1-1.25 mg/kg, two days a time, i.m.) and compared with those from control rats. 5 mumol/L norepinephrine (NE) increased PS; 50 mumol/L NE decreased it slightly. 5 mumol/L isoproterenol (ISO) increased PS. 100 mumol/L phenylephrine (PE) decreased it. The effects of increasing and decreasing PS could be antagonised by beta and alpha adrenergic antagonists, respectively. The effects of NE and PE on PS amplitude showed no significant difference between the control and kindled rats. The effect of beta-adrenergic agonist ISO on PS amplitude in hippocampal slices from partial kindled rats was less than that of control (P < 0.01). The effect of ISO on PS of full kindled rats was partially recovered.

Animals↗
PubMed1992

[A preliminary survey on Zhuang nationality medicinal crops at traditional herbs market of Jingxi County in Guangxi Zhuang Autonomous Region].

This paper reports an investigation and study on the Zhuang nationality medicinal crops available on the traditional herbs market in Jingxi county of Guangxi Zhuang Autonomous Region. There are 380 species belonging to 129 families and 322 genus, among which notably Embelia parviflora, Malus doumeri, Panax notoginseng, Polygala fallax, etc. This study may serve as a reference for exploitation and utilization of the Zhuang nationality medicinal herbs resources.

China↗
PubMed1991

2-Ethylhexanol uncouples oxidative phosphorylation in rat liver mitochondria.

2-Ethylhexanol (70 microM), a non-genotoxic carcinogen and peroxisome proliferator, stimulated oxygen uptake in the perfused rat liver by about 10% during the first 10 min of infusion. Perfusion with a higher, hepatotoxic dose of ethylhexanol (3 mM) led to a transient increase in oxygen uptake followed by a rapid inhibition of respiration of over 50% in 10 min. Lactate dehydrogenase (LDH) release, indicative of irreversible cell death, was detected in the effluent perfusate after 20 min. After 10 min of perfusion with ethylhexanol, livers were freeze-clamped, acid extracts were prepared and adenine nucleotides were measured by high-pressure liquid chromatography. Ethylhexanol decreased the ATP/ADP ratio from 2.5 to 0.9. Thus, marked decreases in hepatic energy state due to inhibition of respiration preceded cell death. To attempt to understand this phenomenon, the effect of ethylhexanol on isolated mitochondria was studied. Similar to classical uncoupling agents, ethylhexanol stimulated state-4 rates of respiration, diminished coupled rates of respiration, and decreased the P/O ratio in a dose-dependent manner in isolated mitochondria. Ethylhexanol also decreased uptake of radiolabeled 45CaCl2 by isolated mitochondria 4- to 5-fold. Therefore, we hypothesize that ethylhexanol initially uncouples oxidative phosphorylation leading to diminished ATP synthesis and collapse of ion gradients across the mitochondrial membrane.

Adenosine Diphosphate↗