Real-time hadron properties at finite temperature from a Euclidean lattice.
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Journal Article↗
Biomedical subjects
S Huang
Publications and source records attributed to S Huang.
Experimentally provoked neural induction results in an incomplete expression of neuronal traits.
In the amphibian embryo, the ectoderm becomes a neural structure during gastrulation as a result of an interaction with the dorsal mesoderm. From that time onward, neurectodermal cells have the ability to express in vitro a large variety of mature phenotypes without further interaction with the inducing tissue. The neuralization of the ectoderm can be reproduced in a variety of experimental situations that do not involve the dorsal mesoderm. In this study we have analyzed biochemically the extent to which artificial inductions mimic the natural inducing process. Making use of antibodies specific to different neurotransmitter pathways, we have shown that the repertoire of the phenotypes expressed by experimentally induced neurons is always restricted compared to those obtained after induction in vivo. Only a limited number of generic neuronal characteristics are expressed. These results suggest that the expression of a complete neuronal phenotype normally involves a sequence of inductive events that can be experimentally uncoupled.
Animals↗
In vivo X-ray fluorescence analysis with applications to platinum, gold and mercury in man--experiments, improvements, and patient measurements.
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Arthritis, Rheumatoid↗
The deficient degradation of synthetic 2- and 3-methyl-branched fatty acids in fibroblasts from patients with peroxisomal disorders.
The oxidation of pristanic and phytanic acids by human skin fibroblasts was compared to that of their synthetic analogues, 2-methylpalmitic and 3-methylmargaric acids. The synthetic compounds and natural substrates were degraded at comparable rates in control and X-linked adrenoleukodystrophy fibroblasts. The alpha-decarboxylation of 3-methylmargaric acid, similarly to that of phytanic acid, was affected in Refsum disease and Zellweger syndrome, but not in X-linked adrenoleukodystrophy. The beta-oxidation of 2-methylpalmitic acid, similarly to that of pristanic acid, was deficient in fibroblasts derived from patients suffering from Zellweger syndrome, confirming the importance of peroxisomes in the breakdown of 2-methyl-branched fatty acids. No deficiency was observed in fibroblasts from X-linked adrenoleukodystrophy patients. The 1-14C-labelled 2- and 3-methyl-branched fatty acids, which are easier to synthesize that the natural analogues, are therefore valuable tools for the diagnosis of human peroxisomal disorders.
Adrenoleukodystrophy↗
Manidipine inhibits endothelin-1-induced [Ca2+]i signaling but potentiates endothelin's effect on c-fos and c-jun induction in vascular smooth muscle and glomerular mesangial cells.
We studied the effects of manidipine, a newly synthesized dihydropyridine Ca2+ channel antagonist, on endothelin-1 (ET-1)-induced [Ca2+]i signaling and immediate-early gene induction in vascular smooth muscle A7r5 cells and glomerular mesangial cells (MCs). ET-1-induced a dose-dependent, biphasic increase in [Ca2+]i in both A7r5 cells and MCs. Manidipine inhibited the ET-1-induced [Ca2+]i increase by reducing both the transient and sustained Ca2+ increments in A7r5 cells and MCs. At concentrations of 10(-10) to 10(-6) mol/L, inhibition was dose dependent with a median effective dose (ED50) of 10(-9) mol/L. A 20-minute preincubation period was required to observe the maximal inhibitory effect of manidipine. In contrast, manidipine (10(-5) mol/L) potentiated ET-1-induced c-fos and c-jun expression in A7r5 cells. This potentiating effect appeared 30 minutes after manidipine was added to the media and lasted for 15 hours. Manidipine alone had no detectable effect on c-fos steady-state messenger ribonucleic acid level. Manidipine induced c-jun expression starting at 60 minutes but with much lower potency. These data demonstrate that manidipine is a potent inhibitor for ET-1-induced [Ca2+]i signaling and that manidipine has multiple effects on ET-1-induced signaling, including potentiating the immediate-early gene response.
Animals↗
Assessment of hematopoietic cell differentiation by multidimensional flow cytometry.
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Animals↗
Use of monoclonal antibodies MSN-1 and B72.3 in the prediction of the natural history of endometrial hyperplasia.
Forty patients, originally diagnosed as endometrial hyperplasia, were reviewed histopathologically and evaluated for immunohistochemical staining with antibodies directed against TAG-72 and MSN-1 antigens. All patients had follow-up endometrial biospies or hysterectomies from 1 to 13 years later. The extent of regression to normal of nonhyperplastic endometrium, persistence as any type of endometrial hyperplasia, or progression to endometrial adenocarcinoma was correlated with the histologic hyperplastic subtype and immunohistochemical staining. As expected, cases of complex or atypical hyperplasia more often progressed to carcinoma than cases of simple or no hyperplasia. Interestingly, MSN-1 positivity was more prevalent in cases of higher grades than lower grades of hyperplasia and was associated with the tendency to show persistent hyperplasia or progression to carcinoma. B72.3 positivity was uncommon in the hyperplastic endometrium and was not correlated with clinical regression or progression. Although the tendency for progression of endometrial hyperplasia to endometrial carcinoma is best judged histologically, MSN-1 may add prognostic information in subgroups of hyperplasia.
Adenocarcinoma↗
Defective and normal haematopoietic stem cells in paroxysmal nocturnal haemoglobinuria.
The expression of decay-accelerating factor (DAF or CD55) and CD59 during haematopoietic cell development in bone marrow aspirates of two patients with paroxysmal nocturnal haemoglobinuria (PNH) was compared with that in normal bone marrow by five-dimensional flow cytometry. In contrast to early uncommitted haematopoietic progenitor cells (CD34+, CD38-) in normal bone marrow which uniformly express DAF and CD59, the majority of CD34+, CD38- cells in both patients' marrow exhibited the absence of the two proteins. In both specimens, however, subpopulations of CD34+, CD38- cells expressing DAF and CD59 were detectable, indicative of the presence of two lines of haematopoiesis, one abnormal and the other normal. Concurrent abnormal and normal haematopoietic development was further evident by the presence of subpopulations of DAF-, CD59- and DAF+, CD59+ cells along the differentiation and maturation pathways of the myeloid (CD33+, CD15(-)-->CD33+-->++, CD15+), the erythroid (CD45dim, CD71dim-->CD45-, CD71++), and the B-lymphoid cell lineages (CD10++, CD20(-)-->CD10-, CD20++). While the majority of cells differentiating into and maturing along each cell lineage lacked DAF and CD59, the majority of mature B (CD20++, CD10-) and T-lymphocytes lymphocytes (CD3+) expressed both proteins suggestive of the presence of lymphocytes with a long life span which were generated from normal haematopoietic progenitors before the onset of the disease. The detection of distinct sets of CD34+, CD38(-)--> + progenitor cells which are DAF+, CD59+ or DAF-, CD59- in marrow of PNH patients has relevance for the treatment of PNH. Cells with the phenotype CD34+, CD38-, DAF+, CD59+ are capable of self renewal and represent potential candidates for autologous bone marrow transplantation following depletion of CD34+, CD38-, DAF-, CD59- cells.
Adult↗
Regulation of energy metabolism in synaptic terminals and cultured rat brain astrocytes: differences revealed using aminooxyacetate.
Several recent studies have demonstrated that the metabolism of energy substrates takes place in multiple compartments in both astrocytes and synaptic terminals from brain. There are a number of differences in the metabolism of astrocytes and synaptic terminals primarily due to the localization of key enzymes such as pyruvate carboxylase and glutamine synthetase in astrocytes. The present study determined the rates of 14CO2 production from several energy substrates by primary cultures of astrocytes and cortical synaptic terminals from rat brain. The rates of 14CO2 production from labelled substrates by astrocytes were 0.96 +/- 0.13, 11.13 +/- 0.67, 10.51 +/- 0.35, 24.92 +/- 1.66 and 4.80 +/- 0.50 for D-[6-14C]glucose, L-[U-14C]lactate, D-3-hydroxy[3-14C]butyrate, L-[U-14C]glutamine and L-[U-14C]ma-late, respectively. The rates of 14CO2 production were also measured in the presence of 5 mM aminooxyacetate (AOAA) to determine the effect of inhibiting the malate-aspartate shuttle and other transaminase reactions on the oxidation of energy substrates. In astrocytes the addition of AOAA decreased the rate of glutamine oxidation 5-fold, consistent with other studies showing that glutamine enters the TCA cycle via transamination. AOAA increased the rate of 14CO2 production from labelled glucose 4-fold, suggesting that inhibition of alanine biosynthesis profoundly alters the utilization of glucose by astrocytes. AOAA also increased the oxidation of lactate and 3-hydroxybutyrate 36 and 58%, respectively. The rates of 14CO2 production from labelled substrates by synaptic terminals were 13.12 +/- 1.05, 35.29 +/- 3.58, 17.66 +/- 1.95, 30.18 +/- 1.10 and 9.95 +/- 1.29, respectively, for glucose, lactate, 3-hydroxybutyrate, glutamine and malate, demonstrating that all substrates were oxidized at a higher rate by synaptic terminals than by astrocytes. The addition of AOAA decreased the rate of 14CO2 production from labelled lactate by 57% suggesting that the use of lactate for energy in synaptic terminals is tightly coupled to the activity of the malate-aspartate shuttle. AOAA had no effect on the rate of 14CO2 production from labelled glutamine, demonstrating that exogenous glutamine enters the TCA cycle in synaptic terminals via glutamate dehydrogenase, not via transamination as is the case with astrocytes. AOAA had no significant effect on the rates of oxidation of glucose, 3-hydroxybutyrate and malate by synaptic terminals. These findings demonstrate that inhibiting transamination with AOAA had very different effects on the oxidation of energy substrates in the two preparations, suggesting that the regulation of metabolism is quite different in astrocytes and synaptic terminals.(ABSTRACT TRUNCATED AT 250 WORDS)
3-Hydroxybutyric Acid↗
Eupenifeldin, a novel cytotoxic bistropolone from Eupenicillium brefeldianum.
Eupenifeldin was isolated from cultures of Eupenicillium brefeldianum ATCC 74184 by extraction and crystallization. The compound was identified as a pentacyclic bistropolone on the basis of spectral data and its complete structure was established by single-crystal X-ray analysis. The compound is cytotoxic against the HCT-116 cell line and has in vivo antitumor activity in the P388 leukemia model.
Animals↗
The normal color vision evaluated with FM 100-hue test.
One hundred and twenty normal subjects (240 eyes) aged from 10 to 69 were tested with FM 100-hue test. They were divided into 6 groups according to their age. It was shown that there were no statistically significant difference in the total error score (TES) between the males and females or between the right and left eyes, but there existed some relationships between the TES and age. The total error score (TES) was the lowest in the 20-29 age group and increased gradually with aging. The analysis of the partial error score (PES) in each age group showed that the PES was the lowest in 20-29 age group and that the larger PES appeared around the axis of titan with age increasing.
Adolescent↗
[Determination of serum pancreatic polypeptide and its clinical significance in patients with end state renal failure].
Serum levels of pancreatic polypeptide (SPP) responding to 75g glucose (oral) challenge were observed in 27 patients with end state renal failure (ESRF) and 27 normal subjects as a control. The results showed that the levels of SPP were significantly higher in ESRF patients than in normal subjects. Dialysis therapy seemed to have no effect on the levels of SPP. The elevated levels of SPP could return to normality after kidney transplantation. There was no positive correlation between the levels of SPP, the blood sugar, and the serum insulin. It is suggested that kidneys are the important sites for the metabolism of PP. The elevated SPP concentration in patients with ESRF may result from their renal failure, and may contribute to some gastrointestinal symptoms which are frequently associated with ESRF.
Adult↗
Temperature correction factors derived from normal subjects may be invalid in demyelinating neuropathies.
This study investigates the temperature effect on motor nerve conduction velocity (MNCV) in patients with neuropathic processes. Fourteen subjects, ages 18-77 yr old, with a diagnosis of uremic polyneuropathies (UPN, n = 5), diabetic polyneuropathies (DPN, n = 6) or carpal tunnel syndrome (CTS, n = 3) and ten normal controls were studied. After limb cooling in a cold water bath for 30 min, skin temperatures were sequentially obtained from the volar midwrist. Motor conduction velocities were obtained at 2-3 degrees increments between 22 and 33 degrees C. Results indicated a large individual variability; 0.1 to 1.8 in the median and 0.8 to 2.0 m/s/degrees C in the ulnar nerve when all three groups are considered together. There was a significant difference between the correction factors for control v DPN and control v CTS. A significant difference was also present for UPN v DPN and UPN v CTS (p < 0.05). There was a positive correlation (r = 0.746, p = 0.0001) between the baseline conduction velocities and the size of the correction factors in all the subjects. The effect of temperature on MNCV appears to be inversely correlated with the severity of conduction slowing or demyelination. These findings suggest that the use of a correction factor may be invalid when studying a demyelinated nerve, and that the extremity should be warmed to a specific temperature before an electrodiagnostic study.
Adolescent↗
Reverse phase open column chromatography determination of urinary riboflavin.
Reverse phase open column chromatography was used to determine urinary riboflavin. An aliquot of a urine specimen was added directly onto the reverse phase open column. The riboflavin was collected and measured as the compound was eluted. The mobile phase (MeOH/H2O/HOAc 37/63/0.1 v/v/v) and stationary phase (C18, 50 microns) were used. The method shows good reproducibility. Recovery of added Vit.B2 was 98.89-100%. The coefficient variation of reproducibility of within day was 1.53%. The coefficients of variation of reproducibility of day-to-day were 0.39% and 1.74% for low and high concentration samples, respectively. The reverse phase open column chromatography was compared to the traditional fluorometric method and HPLC method for riboflavin. The coefficient of linear regression of these comparisons are Y = 0.331 + 1.010X (n = 37, r = 0.984) and Y' = -0.004 + 1.036X' (n = 15, r = 0.999) for RP open column vs. traditional method and RP open vs. HPLC, respectively, where X or X' is the reverse phase open column chromatography method and Y or Y' is the traditional fluorometric method or HPLC, respectively. Concentrations of riboflavin as low as 0.05 micrograms/ml were measured with a linear relation of response to concentration to at least 10 micrograms/ml.
Chromatography↗
The retinal fate of Xenopus cleavage stage progenitors is dependent upon blastomere position and competence: studies of normal and regulated clones.
The clonal origin of the stage 43-44 Xenopus retina from cleavage stage precursors was quantitatively assessed with lineage tracing techniques. The retina descends from a specific subset of those blastomeres that form forebrain. The most animal dorsal midline cell (D1.1.1) produced about half of the retina, the three other dorsal ipsilateral blastomeres each produce about an eighth of the retina, and the four contralateral dorsal blastomeres and an ipsilateral ventral-animal cell together produce the remaining eighth of the retina. There was no significant spatial segregation of the clones derived from different progenitors in either the anterior-posterior or dorsal-ventral axes of the retina and no boundaries between clones were observed. Instead, the clones intermixed to form multiple radial subclones that were equivalent to those demonstrated by marking optic vesicle progenitor cells (Holt et al., 1988; Wetts and Fraser, 1988). This mosaic pattern was initiated by the beginning of gastrulation, advanced in the neural plate, and virtually complete in the optic vesicle. At optic vesicle stages cell movement within subclones was restricted, resulting in the formation of lineally related columns of cells in the mature retina. To determine if the blastomere progenitors are determined to produce these retinal lineage patterns, the major retinal progenitor (D1.1.1) was deleted bilaterally. About 60% of the tadpoles developed normal-appearing eyes; of these the retinas in two-thirds were normal in size and the rest were smaller. The blastomeres surrounding the deleted D1.1.1 progenitors changed their contributions to retina in different ways to effect a complete or partial restoration. Ventral blastomeres, which normally contribute mainly to the tail, produced substantial amounts of the retina while dorsal blastomeres, which normally contribute mainly to the head, decreased their contribution to the retina. To determine whether these changes in retinal lineage were due to changes in blastomere position after the surgery, various other blastomeres were deleted prior to lineage mapping. Dorsal-animal blastomeres took over the retinal fate of their dorsal-vegetal neighbors after those neighbors were deleted, but did not change fate after the deletion of their ventral-animal neighbors. This result suggests that dorsal-animal blastomeres change positional values in only one direction (dorsal to vegetal) after neighbor cell deletion, and that retinal fate is dictated by blastomere position. To test this hypothesis directly, different ventral and vegetal blastomeres, which normally do not produce retina, were transplanted to the position of D1.1.1.(ABSTRACT TRUNCATED AT 400 WORDS)
Animals↗
Clinical and experimental studies on shallow needling technique for treating childhood diarrhea.
Treatment of diarrhea in children by shallow needling and by drugs was studied in 3 separate groups for comparison. For Group I, the lateral line II of the forehead was taken, i.e. the upper, middle and lower points of the line staring from Toulinqi (UB 15) vertically downwards to the place 1 cm below the hairline were selected. For Group II, shallow needling was done on body acupoints, the main points selected being Qihai (Ren 6), Shuifen (Ren 9), bilateral Tianshu (St 25), and bilateral Zusanli (St 36); the adjuvant acupoints were Taibai (Sp 3) and Gongsun (Sp 4). The depth of shallow needling was merely puncturing the skin. For Group III the drugs used were Liteling, Berberine, Gentamycin, Ampicillin, and SMZ Co. The results of treatment in Group I and II differed insignificantly, while both were significantly superior to drugs in Group III. Experimental studies also showed that shallow needling enhanced the humoral and cellular immunity and promoted the intestinal peristaltic function.
Acupuncture Therapy↗
Cytokines, mesangial cell activation and glomerular injury.
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Amino Acid Sequence↗
Sequence and transcriptional analysis of the Escherichia coli rnt gene encoding RNase T.
The Escherichia coli rnt gene encoding the enzyme RNase T, which is responsible for the end-turnover of tRNA, was cloned on a 1.5-kilobase DNA fragment. When placed in pUC18 and pUC19 vectors this fragment led to approximately a 40-fold overexpression of RNase T activity. The cloned fragment was sequenced and was found to contain an open reading frame sufficient to encode a protein of 215 amino acids with a molecular weight of 23,521, which is close to the subunit molecular weight of RNase T; the fragment also contains a second incomplete open reading frame with some sequence similarity to RNA helicases. The derived sequence of RNase T showed no similarity to any of the other E. coli exoribonucleases sequenced to date. Primer extension analysis and deletion of part of the upstream region were used to identify the transcription start point and the promoter of the rnt gene. Northern and primer extension analysis revealed that the rnt message also included the second open reading frame, suggesting that rnt is part of an operon.
Amino Acid Sequence↗