Search PubMed⌕ Search

Biomedical subjects

C L Huang

Publications and source records attributed to C L Huang.

At least 91 records · Page 5Linked to original sources

Mutations of p53 and K-ras genes as prognostic factors for non-small cell lung cancer.

To evaluate the importance of mutations of p53 and K-ras genes in the prognosis of patients with non-small cell lung cancer, one hundred and forty-four patients who underwent surgery were studied. DNA was extracted from frozen specimens. Polymerase chain reaction-single strand conformation polymorphism and sequencing were performed to investigate mutations of p53 from exon 5 to 8, and mutations of exon 1 of K-ras. Mutations of p53 gene occurred in 35. 4% of patients, and mutations of the K-ras gene in 8.3%. The overall survival rate of non-small cell lung cancer patients with wild-type K-ras was better than that of patients whose tumors had mutations of K-ras (P=0.0330). Among patients with adenocarcinoma of the lung, the overall survival rate of patients with wild-type p53 was strikingly better than that of patients whose tumors had mutations of p53 (P=0.0234). Multivariate analysis with the Cox regression model of all patients with non-small cell lung cancer and those with adenocarcinoma indicated that mutations of K-ras best correlated with the overall survival rate (P=0.0005 and P=0.0361, respectively). In conclusion, evaluation of mutations of both the p53 and K-ras genes in the lung tumors might be useful for assessing the prognosis, especially in patients with adenocarcinoma.

Adenocarcinoma↗

Therapy-related leukemia and myelodysplasia following oral administration of etoposide for recurrent breast cancer.

We report a high risk of therapy-related acute myeloid leukemia and myelodysplastic syndrome (t-AML/MDS) in patients receiving oral administration of etoposide for recurrent breast cancer. We examined 119 patients with recurrent disease. Patients were initially treated with anthracyclines, cyclophosphamide, or cisplatin with or without radiation before etoposide treatment. Etoposide was used as the final drug in most cases. Twenty-four patients were treated with the oral administration of etoposide (50 or 100 mg/day for 5-7 days at 4-week intervals). Three cases of t-AML/MDS developed among those 24 patients exposed to etoposide. In contrast, the development of t-AML/MDS was not observed in the other 95 patients not treated with etoposide. Our data suggest that there is a substantial risk of secondary leukemia with oral administration of etoposide for a prolonged period as well as i.v. schedules.

Administration, Oral↗

Dual actions of tetracaine on intramembrane charge in amphibian striated muscle.

1. The effects of graded concentrations of tetracaine on the steady-state and kinetic properties of intramembrane charge were examined in intact voltage-clamped amphibian muscle fibres. 2. The micromolar tetracaine concentrations that were hitherto reported to abolish Ca2+ transients in skeletal muscle failed to affect significantly the steady-state charge. Maximal reductions of such intramembrane charge required relatively high, 1-2 mM, concentrations of tetracaine. 3. The plots of maximum charge against tetracaine concentration suggested a saturable 1:1 drug binding that spared a fixed amount of tetracaine-resistant (q beta) charge but inhibited a discrete fraction of susceptible (q gamma) charge with a KD between 0.1 and 0.2 mM. 4. The q beta charge thus isolated by 2 mM tetracaine was conserved through a wide range of applied test voltages and pulse durations and regardless of whether the imposed transition from the holding potential (-90 mV) to the test potential took place in one or more steps. 5. Similarly, 'on' and 'off' q beta currents that were elicited by voltage steps from fixed conditioning to varying test levels mapped onto non-linear phase-plane trajectories that nevertheless depended uniquely upon voltage. In contrast, the currents that followed voltage steps made from varying prepulse levels to fixed -90 or -20 mV test potentials mapped onto identical q beta phase-plane trajectories that were independent of the prepulse history. 6. The charge movements that followed strong depolarizing voltage clamp steps to test potentials in the range -50 to 0 mV approximated simple monotonic decays that could empirically be described by a single time constant. Nevertheless, a complete inhibition of a tetracaine-sensitive (q gamma) charge movement by 2 mM tetracaine that left only q beta charge, sharply altered both the magnitude and the voltage dependence of these time constants. This establishes a distinct contribution of the q gamma species to overall charge kinetics even at such test voltages. 7. Under such a criterion for the voltage dependence of charging kinetics, even the micromolar (0.05-0.2 mM) tetracaine concentrations that failed to markedly alter the steady-state charge consistently increased the charging time constants yet did not influence their voltage sensitivity. 8. These findings demonstrate the existence of separate kinetic and steady-state effects of tetracaine on intramembrane charge movements, at micromolar and millimolar anaesthetic concentrations, respectively. These parallel earlier effects of tetracaine that have been reported upon the transient and sustained components of sarcoplasmic reticular Ca2+ release. They also establish that maximally effective concentrations of tetracaine isolate a single distinct species of conserved (q beta) intramembrane charge.

Anesthetics, Local↗

Immunohistochemically detected expression of motility-related protein-1 (MRP-1/CD9) in lung adenocarcinoma and its relation to prognosis.

Motility-related protein-1 (MRP-1)/CD9 is a trans-membrane glycoprotein closely associated with suppression of cell motility and reduced metastatic potential of some tumor cells. We currently report that, according to the RT-PCR method for MRP-1/CD9 gene expression, patients with low expression of MRP-1/CD9 in non-small-cell lung cancer, especially the adenocarcinoma type, showed short overall survival. Then, to determine accurately the prognostic value of MRP-1/CD9 product levels in lung-adenocarcinoma cells, we immunohistochemically investigated its expression in 132 lung-adenocarcinoma patients undergoing potentially curative surgery. Of these patients, 44 (33%) showed reduced expression of MRP-1/CD9 in cancer cells, and an inverse association was observed between its expression and factors associated with tumor progression, such as nodal involvement (p = 0.029) or stage (p = 0.028). Patients with reduced expression of MRP-1/CD9 showed a significantly worse prognosis in overall survival (p = 0.005) and disease-free survival (DFS; p < 0.0001) than those with stronger expression; and even among patients with stage-I disease, similar results were obtained (overall survival, p = 0.038; DFS, p = 0.012). In a multivariate analysis, immunohistochemical MRP-1/CD9-expression level was an independent prognostic factor for DFS (p = 0.021), but not for overall survival (p = 0.572). Thus, immunohistochemical MRP-1/CD9-expression level solely in lung-adenocarcinoma cells within the tumor tissue appears to be a prognostic factor for DFS, and may be useful for detecting a high-risk sub-group of recurrence during the post-operative clinical course of the disease.

Adult↗

Binding of the G protein betagamma subunit to multiple regions of G protein-gated inward-rectifying K+ channels.

We have previously shown that direct binding of the betagamma subunit of G protein (G betagamma) to both the N-terminal domain and the C-terminal domain of a cloned G protein-gated inward-rectifying K+ channel subunit, GIRK1, is important for channel activation. We have now further localized the G betagamma binding region in the N-terminal domain of GIRK1 to amino acids 34-86 and the G betagamma binding region in the C-terminal domain of GIRK1 to two separate fragments of amino acids 318-374 and amino acids 390-462. Of the four cloned mammalian GIRK subunits, GIRK1-4, GIRK1 and 4 form heteromeric K+ channels in the heart and similar channels in the brain include heteromultimers of GIRK1 and 2, and possibly other GIRK homomultimers and heteromultimers. We found that the N-terminal and the C-terminal domains of all four GIRKs bound G betagamma. The G betagamma binding activities for the C-terminal domains of GIRK2-4 were lower than that for the C-terminal domain of GIRK1. The higher G betagamma binding activity for the C-terminal domain of GIRK1 is due to amino acids 390-462 which are unique to GIRK1. We also found that the N-terminal and C-terminal domains of GIRKs interacted with each other, and the N-terminal domain of either GIRK1 or GIRK4 together with the C-terminal domain of GIRK1 exhibited much enhanced binding of G betagamma. These results are consistent with the idea that the N- and C-terminal domains of the cardiac G protein-gated K+ channel subunits may interact with each other to form higher affinity binding site(s) for G betagamma.

Amino Acid Sequence↗

A study of large congenital melanocytic nevi and associated malignant melanomas: review of cases in the New York University Registry and the world literature.

BACKGROUND: Patients with large congenital melanocytic nevi (LCMN) are at greater risk for the development of malignant melanoma (MM) than are persons in the general population. OBJECTIVE: Our purpose was to identify the clinical features of LCMN in those patients in whom MMs actually developed. METHODS: The records of 117 patients in the New York University Registry of LCMN and the reports of 172 cases of LCMN in the world literature were studied. RESULTS: Of the 289 cases of LCMN studied, 34 patients (12%) had primary cutaneous MMs within their nevi; in two additional patients, MMs developed at cutaneous sites other than within their nevi. All patients in whom MM developed within LCMN had nevi in axial locations; however, 91% of the LCMN were axial. No MM was found that had arisen in any of the 26 LCMN confined to the extremities. In addition, no MM was found that had arisen in thousands of satellite nevi. CONCLUSION: When MM develops within an LCMN, it generally does so in those LCMN in an axial location. The absence of cases of MM arising in LCMN confined to the extremities suggests that such nevi represent lower risk lesions, but the number of extremity nevi analyzed was too small to allow definitive conclusions. A striking finding was the absence of MMs arising in satellite nevi.

Humans↗

Optimised diffusion-weighting for measurement of apparent diffusion coefficient (ADC) in human brain.

This work studies the effect of diffusion-weighting on the precision of measurements of the apparent diffusion coefficient (ADC, or D) by diffusion-weighted magnetic resonance imaging. The precision in the value of the ADC was described in terms of a diffusion-to-noise ratio (DNR) which was calculated as the signal-to-noise ratio in the resultant ADC. A theoretical analysis decomposed the DNR into the signal-to-noise ratio in the diffusion-weighted image and the sensitivity of diffusion-weighting, "KD". The latter reflects the effect of the sampling strategy in the diffusion-weighting domain on the DNR. The theoretical analysis demonstrated that optimal two-point diffusion-weighting could be achieved in the vicinity of zeta = D(b2-b1) = 1.1, where zeta is a non-dimensional parameter of diffusion-weighting, and b1 and b2 are the diffusion-weighting factors for the two-point diffusion-weighting. This approach also derived an optimised signal averaging scheme. The limitations and restrictions of the two-point scheme for in vivo ADC measurement were also considered; these included a detailed discussion on partial volume effects. The theory was verified by experiments on phantoms and on the brain of a healthy volunteer using a diffusion-weighted echo-planar imaging protocol. This led to an optimal two-point diffusion-weighting for ADC measurement in human brain using b1 = 300, and b2 = 1550 +/- 100 s/mm2. Such a two-point scheme successfully measured values of the ADC in gray matter, white matter and cerebrospinal fluid in human brain. It thus offers an alternative to the commonly used multiple-point schemes and has the advantage of requiring significantly shorter imaging times.

Adult↗

Osmotic 'detubulation' in frog muscle arises from a reversible vacuolation process.

Isolated Rana temporaria sartorius muscle fibres were subject to introduction and subsequent withdrawal of 400 mM extracellular glycerol, exposures to high divalent ion concentrations and then cooling. Tubular detachment was then assessed through changes in the action potential afterdepolarization. (1) The rapid (5-10 min) rather than slow cooling step (30 min) produced a gradual (30 min) development of detubulation arrested by the subsequent replacement of glycerol and reversed by addition of 350 mM sucrose. Such osmotic agents influenced neither resting potentials of intact or detubulated fibres nor action potentials in intact fibres. (2) Full tubular detachment was achieved by 40 min. Laser epifluorescence microscopy demonstrated an accompanying tubular vacuolation through its trapping of a Rhodamine dye. (3) Subsequent re-additions (at 10-80 min) of glycerol restored the afterdepolarization in 30% of detubulated fibres and correspondingly reduced vacuolation. Sustained (> 60 min) exposures to 350 mM sucrose, applied between 30-60 min, both reversed tubular isolation in 70% of detubulated fibres and abolished tubular vacuolation. Finally, results from transient (10-30 min) sucrose exposures resembled the consequences of sustained applications of glycerol, suggesting that detubulation and its reversal result from an osmotic mechanism. (4) Nevertheless, irreversible changes developed after 70-80 min in 70% of detubulated fibres, a process hastened by slow cooling steps in the initial osmotic stress. The present study thus correlates morphological and electrophysiological consequences of applying osmotic shock to skeletal muscle for the first time. It additionally differentiates reversible and irreversible components of detubulation. Finally, it suggests that detubulation results from the similarly reversible vacuolation observed under comparable osmotic conditions, and that such vacuolation can eventually lead to irreversible detubulation.

Action Potentials↗

Effects of NMDA on carbachol-stimulated phosphatidylinositol resynthesis in rat brain cortical slices.

N-methyl-D-aspartate (NMDA) inhibits carbachol-stimulated phosphoinositide breakdown in rat brain cortical slices but not in isolated membranes (1). To gain insight into the mechanisms, we examined the effects of NMDA on carbachol-stimulated [3H]inositol phosphate and intermediates of phosphatidylinositol cycle accumulation in rat cortical slices. The inhibition is primarily on the synthesis of inositol phospholipids subsequent to activation of muscarinic cholinergic receptors. In the absence of lithium, NMDA inhibited carbachol-stimulated [32P]PtdIns but not [32P]PtdOH synthesis. Carbachol-stimulated CDP-DAG formation required trace amount of Ca2+ and the response was inhibited by NMDA at low but not high extracellular Ca2+ concentrations. The inhibition due to NMDA was only seen at millimolar extracellular Mg2+. The inhibition of carbachol-stimulated CDP-DAG formation was not affected by adding tetrodotoxin or cobalt chloride suggesting the inhibitory effect was not due to releasing of neurotransmitters. The inhibitory effects of NMDA could be abolished by MK-801, the specific NMDA receptor associated channel antagonist. When cortical slices were preincubated with ligands and lithium to allow the build up of CDP-DAG, carbachol stimulated the incorporation of [3H]PtdIns. However, this response was not inhibited by NMDA. These results suggest that CDP-DAG synthesis is the primary site of regulation by NMDA. Because CDP-DAG cytidyltransferase requires Mg2+ as cofactor and is sensitive to Ca2+ it is possible that NMDA inhibits ligand-stimulated PtdIns breakdown by blocking the replenish of agonist-sensitive PtdIns pool through changes of divalent cation homeostasis.

Animals↗

Cutaneous involvement in polyvinylpyrrolidone storage disease: a clinicopathologic study of five patients, including two patients with severe anemia.

Polyvinylpyrrolidone (PVP), formerly a plasma expander, has continued to be inappropriately used in Taiwan for intravenous injection as a "blood tonic." Five cases of PVP storage disease with cutaneous involvement were studied. Two patients presented with cutaneous eruptions mimicking collagen vascular disease and chronic pigmented purpuric dermatosis. Two other cases were found incidentally: one was with a metastatic tumor and the other in a pemphigus lesion. The fifth case was seen in a blind skin biopsy specimen taken to exclude Niemann-Pick disease after hematologic examination of a bone marrow smear. The latter patient and the patient with a collagen vascularlike disease also had severe anemia and serious orthopedic and neurologic complications due to massive infiltration of PVP-containing cells in the bone marrow with destruction of the bone. Severe irreversible anemia due to PVP storage disease has not been reported before. Three patients admitted having a history of receiving intravenous injection of PVP. The samples obtained from two of them indeed contained 5% PVP as determined by chemical analysis. PVP storage disease can be diagnosed by its histopathologic features. The skin biopsy specimens all showed a variable number of characteristic blue-gray vacuolated cells around blood vessels and adnexal structures with positive tinctorial reactions to mucicarmine, colloidal iron, and alkaline Congo red and negative to periodic acid-Schiff (PAS) and alcian blue. The PVP storage cells were shown to be CD68+ macrophages. The presence of PVP in the skin induced little or no inflammatory reaction. Only the pelvic mass in one patient had a foreign body granuloma formation. Our study showed that systemic parenteral administration of PVP preparation could result in the accumulation of PVP storage cells in the skin, with or without clinical eruptions. The diagnosis of systemic PVP storage disease can be established by performing a skin biopsy for pathologic study. It is important for pathologists and clinicians to be aware of this iatrogenic storage disease to avoid misdiagnosis for hereditary storage disease, osteomyelitis, or signet-ring cell carcinoma. Serious hematologic and orthopedic complications can be caused by repeated massive intravenous injection of PVP. Therefore, PVP preparations should be strictly prohibited for systemic administration.

Adult↗

Three-dimensional PET emission scan registration and transmission scan synthesis.

The duration of a positron emission tomography (PET) imaging scan can be reduced if the transmission scan of one patient which is used for emission correction can be synthesized by using the reference transmission scan of another patient. In this paper, we propose a new intersubjects PET emission scan registration method and PET transmission synthesis method by using the boundary information of the body or brain scan of the PET emission scans. The PET emission scans have poor image quality and different intensity statistics so that we preprocess the emission scans to have similar histogram and then apply the point distribution model (PDM) [15] to extract the contours of the emission scan. The extracted boundary contour of every slice is used to reconstruct the three-dimensional (3-D) surface of the reference set and the target set. Our registration is 3-D surface-based which uses the normal flow method [17] to find the correspondence vector field between two 3-D reconstructed surfaces. Since it is difficult to analyze internal organ using the PET emission scan imaging without correction, we assume that the deformation of internal organ is homogeneous. With the corresponding vector field between the two emission scans and the transmission scan of the reference set, we can synthesize the transmission scan of the target set.

Abdomen↗

The effect of glycolic acid on the treatment of acne in Asian skin.

BACKGROUND: Glycolic acid has become important and popular for treating acne. OBJECTIVE: To evaluate the efficacy and safety of serial glycolic acid peels with glycolic acid home care products on facial acne lesions and other associated skin problems. METHODS: We collected 40 Asian candidates with moderate to moderately severe acne. They were divided into two groups according to the degree of greasiness of their facial skin. The two groups' members were treated with four series of 35% and 50% glycolic acid peels, respectively. They also used 15% glycolic acid home care products during this study period. The improvement of acne as well as other associated problems were assessed by both the physicians and the patient themselves. RESULTS: Significant resolution of comedones, papules, and pustules was found. The skin texture of each candidate was dramatically rejuvenated. Consistent and repetitive treatment with glycolic acid was needed for the apparent improvement of acne scars and cystic lesions. The follicular pores also became comparatively smaller. Furthermore, most of the candidates had much brighter and lighter looking skin. Only small percentage of patients (5.6%) developed side effects. CONCLUSION: Glycolic acid has considerable therapeutic value for acne with minimal side effects even in Asian skin. It may be an ideal adjunctive treatment of acne.

Acne Vulgaris↗

A quantitative description of dynamic left ventricular geometry in anaesthetized rats using magnetic resonance imaging.

We report a functional application of magnetic resonance imaging (MRI) for the quantitative description of left ventricular geometry through systole and diastole in normal anaesthetized Wistar rats that might be applicable for the analysis of chronic changes resulting from pathological conditions. Images of cardiac anatomy were acquired through planes both parallel and perpendicular to the principal cardiac axis at times that were synchronized to the R wave of the electrocardiogram. The images of the transverse sections were assembled into three-dimensional representations of left ventricular geometry at consecutive time points through the cardiac cycle. This confirmed the geometrical coherence of the data sets, that each slice showed circular symmetry, and that the images were correctly aligned with the appropriate anatomical axes. Different models for the three-dimensional geometry of the left ventricle were then tested against the epi- and endocardial surfaces reconstructed from images of the transverse sections of the left ventricle in both systole and diastole using least-squares minimizations in three dimensions. In agreement with previous reports in the human heart, an elliptical figure of revolution offered an optimal fit to the epicardial and endocardial geometry for the rat heart in diastole. This was in preference to models that used spherical, quartic or parabolic geometries. However, in contrast to contraction in the human heart, all these geometrical representations broke down during systolic ejection in the rat heart. We therefore introduced a more general hybrid model which described left ventricular geometry in terms of the variation of the radii r(z), independently determined for each slice, with its position z along the principal cardiac axis. The resulting function r(z) could then be described by a simple ellipsoid of revolution not only during diastole, but also throughout ventricular ejection. The findings also ruled out alternative geometrical representations. It was then possible additionally to reconstruct the luminal and total left ventricular volumes, wall thicknesses and ejection fractions through the cardiac cycle and to confirm that the predicted total ventricular wall volume was conserved throughout the cardiac cycle. Our hybrid model of cardiac geometry may thus be useful for non-invasive serial studies of chronic pathological changes that use the rat as a model experimental system.

Animals↗

Industrial workers' health and environmental pollution under the new international division of labor: the Taiwan experience.

Using Taiwan as an example, this paper conducts a historical analysis of the relationship between economic development in the new international division of labor and environmental pollution and industrial workers' health. Three industries-asbestos, plastic, and dye-were chosen for case studies. We trace the emergence of each industry in Taiwan and study each industry's protection of workers' health and environmental quality. Under the new international division of labor, the state's prioritization of economic development leads to lenient regulation. Under such state policies, employers have few incentives to invest in the protection of their workers' health and in the control of environmental pollution. Workers and the public are constrained in their efforts to protect their own health and prevent environmental pollution. This situation is exemplified by the deplorable working conditions and inadequate environmental pollution controls in the asbestos, plastic, and dye industries. Workers' health and the public's health are greatly compromised by economic development in the new international division of labor.

Asbestos↗

[Effect of jishentang on renal lesions in diabetic rats].

OBJECTIVE: To observe the ameliorative effect of Jishentang (JST) on renal lesions in experimental diabetic rats. METHODS: The diabetic rats were randomly divided into three groups: group with out treatment, group with enalapril treatment (the dose of enalapril was 1 mg/kg.d) and group with JST treatment (the dose of JST was 22.4 g/kg.d). The treatment lasted for 8 weeks. RESULTS: (1) JST treatment attenuated the renal hypertrophy and ratio of kidney and body weight (P < 0.01). (2) JST treatment reduced the levels of SCr and BUN and the levels of Alb, beta 2-m and the activity of NAG in urine in diabetic rats significantly (P < 0.01). The levels of TG and TCh decreased and the levels of HDL-C increased in the serum of the JST treated diabetic rats (P < 0.01). (3) The glomerular basement membrane thickening and volume density of PAS positive staining in mesangial area were significantly decreased in JST treated diabetic rats. CONCLUSIONS: JST exerted obvious ameliorative effect on renal function and structure in diabetic rats.

Animals↗

Analysis of epitope structure of PSP94 (prostate secretory protein of 94 amino acids): (II). Epitope mapping by monoclonal antibodies.

PSP94 has shown potential to be a serum biomarker for evaluating prostate cancer. Studies of the epitope structure is crucial for this endeavour. In this article, we have used 15 different monoclonal antibodies (MAb) to analyse the epitope structure of PSP94 and to compare with the results obtained from our previous work using polyclonal antibody and recombinant PSP94. Firstly, we determined the relative activities of the 15 MAb population by direct and competitive ELISA. The two predominant MAbs (MAb PSP-6 and -19) in 15 MAbs were selected for further studies of the epitope structure. By comparing the binding activities of recombinant GST-PSP94 and natural PSP94 with MAbs, and by comparing their affinity with MAbs in an in vitro denaturing experiment, PSP94 was shown to have a similar, prevalently linear epitope structure as we demonstrated by polyclonal antibody. Using recombinant GST fusion protein with PSP94 and with each half of the N- and C-terminal 47 amino acids (GST-PSP-N47/C47) in E. coli cells, the different epitopes recognized by 15 monoclonal antibodies were delineated and the polar distribution of the epitope structure of PSP94 was characterized. Results of direct ELISA of recombinant N47 and C47 and their competitive binding against natural PSP94 (competitive ELISA) showed that the N- and C-termini represent the immuno-dominant and immuno-recessive area separately. A majority of the monoclonal antibodies (12/15) showed preferential binding of the N-terminal sequence of the PSP94 protein. Using GST-PSP-N47 as a standard protein, an epitope map of the 15 monoclonal antibodies was obtained. The results of this study will help to define the clinical utility of PSP94.

Animals↗

Bacterial meningitis and lumbar epidural hematoma due to lumbar acupunctures: a case report.

A 48-year-old female expressed signs of meningeal irritation after having received several lumbar acupunctures within one week for back pain. Bacterial meningitis was diagnosed from cerebrospinal fluid examinations. Magnetic resonance image (MRI) of spine at admission demonstrated a fusiform lesion with characters of subacute hematoma in the epidural space of the first and second lumbar level. She received antibiotics treatment only and recovered from her central nervous system infection completely. The epidural lesion disappeared spontaneously in the MRI follow up three weeks later. We report the diagnosis and follow-up of epidural hematoma of the lumbar spine by MRI which aided the medical physician to treat meningitis attentively.

Acupuncture Therapy↗