Biomedical subjects

S S Chen

Publications and source records attributed to S S Chen.

At least 19 recordsLinked to original sources

PubMed2002

The correlation between pretreatment serum hormone levels and treatment outcome for patients with prostatic cancer and bony metastasis.

OBJECTIVE: To evaluate whether pretreatment serum hormone levels are a prognostic factor for prostatic cancer with bony metastasis under hormonal treatment. PATIENTS AND METHODS: Between 1980 and 1994, 96 patients with prostate cancer and bony metastasis were included for an evaluation by a retrospective review of their charts. All 96 had received hormonal treatment after a diagnosis of metastatic prostatic carcinoma. Serum testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin were assessed before treatment. The patients were divided into two groups according to their response during the follow-up. Group 1 (good response) had no change or resolution of metastatic lesion(s) on the bone scan and a declining prostate-specific antigen (PSA) level. Group 2 had increased PSA or progression of metastatic lesion(s) on the bone scan. Tumours were graded as low (2-4), intermediate (5-7) and high (8-10) using the Gleason score. RESULTS: There were 43 patients in group 1 and 53 in group 2; the overall mean (sd) age was 72.5 (6.8) years and the follow-up 29.5 (0.5) months. The respective mean (sd) levels of testosterone, LH, FSH and prolactin before treatment were 4.6 (1.6) ng/mL, 20.2 (13.3) mIU/mL, 19.6 (18.6) mIU/mL and 20.7 (12.1) ng/mL in group 1, and 2.6 (1.0) ng/mL, 27.3 (11.0) mIU/mL, 27.1 (9.8) mIU/mL and 41.3 (28.4) ng/mL in group 2. The level of testosterone was significantly higher in group 1 than in group 2, while LH, FSH and prolactin were significantly lower in group 1 than in group 2. When stratified by tumour grade, patients in group 1 still had significantly higher pretreatment testosterone and lower LH, FSH and prolactin than those in group 2. CONCLUSION: Higher testosterone and lower LH, FSH and prolactin levels were good prognostic factors for patients with metastatic prostatic cancer under hormonal treatment, irrespective of tumour grading.

Aged↗

PubMed2002

The biological behaviour of human adenoid cystic carcinoma cells transduced with interleukin-2-gene.

Adenoid cystic carcinoma (ACC) of the salivary glands is a highly infiltrative malignant tumour with a tendency for lung metastasis. Gene therapy could be a potentially effective therapy for ACC and its metastasis. The aims of the study were: To transduce interleukin-2 (IL-2) gene into an ACC cell line with predisposition for lung metastasis (ACC-M); to compare the bioactivity of the gene-transduced cells and the parent cell line in vitro and in vivo. The IL-2 gene was transduced via a bicistronic retroviral vector into the ACC-M cells. The growth rate and DNA cell cycles of the parent ACC-M, the control viral vector AmGCEN, and the gene transduced AmIL-2 cell cultures were compared quantitatively and by flow cytometry, respectively. The tumourigenic ability of the three cell lines was verified by inoculation in athymic nude mice. The tumours developed were extracted and compared quantitatively and histologically. There was no difference in the growth rate and the DNA count between the ACC-M, AmGCEN, and AmIL-2 cell cultures. In the animal experiment, both the ACC-M and AmGCEN cells stimulated lung metastasis in all the mice, whereas there was no tumour found in the 1 x 10(6) AmIL-2 cells inoculation. On 3 x 10(6) AmIL-2 cells stimulation, three out of six mice developed tumours but the mass and volume of the tumours were smaller than the other two groups. Under light microscopy, the ACC-M tumours were mainly poorly differentiated with minimal cellular matrix, whereas the AmIL-2 tumours were well differentiated with ample matrix. The transduction of IL-2 gene can reduce the tumourigenicity of ACC-M cells and induces tumour cell differentiation in mice. The IL-2 gene can be a potential effective gene for the treatment of adenoid cystic carcinoma of salivary glands and its lung metastasis.

Animals↗

PubMed2001

Baicalin is a major component of PC-SPES which inhibits the proliferation of human cancer cells via apoptosis and cell cycle arrest.

BACKGROUND: PC-SPES is an eight-herb mixture that was shown to have activity against prostate cancer. Recently, we isolated a major component (6% of the total ethanolic extract) known as baicalin from PC-SPES by high performance liquid chromatography (HPLC). METHODS: Baicalin was evaluated for its ability to inhibit clonal growth, and to induce cell cycle arrest of various cancer types (PC-3, DU145, LNCaP prostate cancer cell lines, MCF-7 breast cancer cell line, HL-60 myeloblastic leukemia cell line, and NB4 promyelocytic leukemia cell line). The ability of baicalin to induce apoptosis of cancer cells was examined by both staining with Annexin V and detection of cleavage of Poly (ADP-ribose) polymerase (PARP)(3). Western blot analysis examined the effect of baicalin on levels of p21(waf1) and p27(kip1) in those cells. Futhermore, induction of differentiation in HL-60 cells was measured by expression of CD11b. RESULTS: Baicalin inhibited the clonal proliferation of LNCaP and PC3 prostate cancer cell lines, and the HL-60 and NB4 myeloblastic/promyelocytic leukemia cell lines with a 50% inhibition (ED(50)) that ranged between 6.4 x 10(-6) to 12 x 10(-6) mol/L. Cell cycle analysis showed that baicalin (2 x 10(-5) mol/L, 4 days) caused a G(0)/G(1) and G(2)/M accumulation of LNCaP and HL-60 cells, respectively. Concomitantly, differentiation and apoptosis were induced in HL-60 cells, as measured by expression of CD11b antigen, staining with annexin V, and detection of cleavage of PARP. Moreover, baicalin enhanced the expression of the cyclin-dependent kinase inhibitor, p27(kip1) in LNCaP and HL-60 cells. CONCLUSIONS: Baicalin inhibited the proliferation of cancer cells via apoptosis and cell cycle arrest, in which p27(kip1) may play a role. Baicalin may be a novel, adjunctive therapy for selected malignancies including prostate cancer.

Annexin A5↗

PubMed2001

Up-regulation of Fas ligand expression by human cytomegalovirus immediate-early gene product 2: a novel mechanism in cytomegalovirus-induced apoptosis in human retina.

Human CMV (HCMV) is an important pathogen that causes widespread diseases in immunocompromised individuals. Among the opportunistic HCMV infections, HCMV retinitis is most common in transplant recipients and AIDS patients. It often leads to blindness if left untreated. The question as to how HCMV infection causes retinal pathogenesis remains unresolved. Here, we report that viral immediate-early gene product 2 (IE2), but not IE1, up-regulates the Fas ligand (FasL) expression in HCMV-infected human retinal pigment epithelium cells. Increased secretion of FasL from virally infected cells into cultured medium was observed upon HCMV infection. The capability of such cell-free medium to induce apoptosis of Fas (CD95)-expressing Jurkat cells further implies that Fas-FasL interaction might mediate cell death in the lesion of HCMV retinitis. To support this idea, we observed augmented soluble FasL levels in vitreous from AIDS patients with HCMV retinitis as compared with that from AIDS patients without HCMV infection. In addition, by in situ hybridization and immunohistochemistry, we detected enhanced signals of FasL, the existence of viral IE Ags and apoptotic cells at the same sites in the lesion of HCMV-infected retina. These results strongly suggest that IE2 induction of FasL expression in human retina might be an important event that takes place in the early stage of infection and finally leads to visual loss in individuals affiliated with HCMV retinitis.

AIDS-Related Opportunistic Infections↗

PubMed2001

Oxidative damage to proteins and decrease of antioxidant capacity in patients with varicocele.

To examine oxidative damage to blood proteins in the spermatic vein and seminal plasma antioxidant capacity of patients with varicocele, 30 young male patients with varicocele (group 1), 25 young male patients with subclinical varicocele (group 2), and 15 normal young males without varicocele (group 3) were recruited in this study. Varicocele and subclinical varicocele were confirmed by physical examination and Doppler ultrasonography. Blood samples were drawn from peripheral and spermatic veins before varicocelectomy. Plasma protein carbonyls were measured by a spectrophotometric assay after reacting with 2,4-dinitrophenylhydrazine. Protein thiols and ascorbic acid of seminal plasma were measured by spectrophotometric methods. We found that plasma protein carbonyls in the spermatic veins were significantly higher than those of corresponding peripheral veins in all 30 patients in group 1 and 12 patients in group 2 receiving varicocelectomy. Protein carbonyls in the spermatic veins of patients with varicocele (3.72 +/- 0.56 nmole/mg protein) and patients with subclinical varicocele (3.50 +/- 0.30 nmole/mg protein) were found to be higher than those of the control (2.35 +/- 0.33 nmole/mg protein). Protein thiols were 0.97 +/- 0.96, 1.50 +/- 0.89, and 3.49 +/- 0.81 nmole/ml, and ascorbic acid levels were 1.87 +/- 0.42, 2.13 +/- 0.24, and 2.38 +/- 0.07 mg/dl, in seminal plasma of the patients in groups 1, 2, and 3, respectively. Seminal plasma protein thiols and ascorbic acid levels in group 1 were significantly lower than those in groups 2 and 3, respectively. These results indicate that oxidative stress in the patients with varicocele and subclinical varicocele was higher than that of the control. We suggest that plasma protein carbonyls, and protein thiols and ascorbic acid of seminal plasma are useful markers for the assessment of oxidative stress in patients with varicocele and subclinical varicocele.

Adult↗

PubMed2001

Efficient tumor regression induced by genetically engineered tumor cells secreting interleukin-2 and membrane-expressing allogeneic MHC class I antigen.

PURPOSE: To analyze the immunotherapeutic potentials of genetically engineered tumor cells secreting IL-2 and a membrane-expressing allogeneic MHC class I molecule Kb in a murine hepatoma model. METHODS: In order to express both genes in coordination in the target cells, we constructed a polycistronic retroviral vector containing Kb, IL-2, and NeoR genes using two internal ribosome entry sites (IRES). Tumor growth was carried out by implantation of transduced tumor cells into mouse, while anti-tumor effects were demonstrated by the treatment of established tumors. The infiltrated cells were analyzed by immunohistochemistry. RESULTS: The combined effect of IL-2 secretion and alloantigen expression on immunostimulation was demonstrated by the rejection of transduced tumor cells. In the treatment of established tumors, the Kb/IL-2 co-expressing tumor cells induced strong anti-tumor immunity, superior to that induced by the single gene-transduced cells. The increased diversity of infiltrated cell types in tumor sites indicated that both a specific and non-specific immune response had been activated. CONCLUSION: Our study provides evidence that tumor cells with IL-2 secretion and membrane-expression of allogeneic MHC class I antigen are capable of inducing both strong tumor rejection and immunity.

Animals↗

PubMed2001

Depth-dependent compressive properties of normal aged human femoral head articular cartilage: relationship to fixed charge density.

OBJECTIVES: Determine the depth-varying confined and osmotic compression moduli of normal human articular cartilage from the femoral head, and test whether these moduli are dependent on fixed charge density. METHODS AND RESULTS: Using an automated instrument to allow epifluorescence microscopy analysis during confined compression testing on cartilage samples, the equilibrium confined compression modulus (H(A 0)) was found to vary markedly with depth (z=0-1500 microm) from the articular surface. H(A 0) increased from 1.16+/-0.20 MPa in the superficial (0-125 microm) layer to 7.75+/-1.45 MPa in the deepest (1250-1500 microm) layer tested, and was fit by the expression, H(A 0)(z) [MPa]=1.44 exp(0.0012.z [microm]). Also, in successive slices of cartilage extending from the articular surface to the middle-deep regions, the bulk modulus (K(0)) and fixed charge density (FCD) increased, consistent with previous findings. While H(A 0), K(0), and FCD each varied with depth from the articular surface, the dependence of H(A 0) and K(0) on depth did not appear to be completely related to variations in FCD. CONCLUSIONS: The confined compression modulus of normal aged human femoral head articular cartilage increases markedly with depth from the articular surface, a trend similar to that observed for articular cartilage from other joints in animals but with an absolute amplitude that is several-fold higher. The compressive properties were not simply related to FCD at different depths from the articular surface, suggesting that other as yet undefined factors also contribute to compressive properties.

Aged↗

PubMed2001

Growth stress distribution in leaning trunks of Cryptomeria japonica.

The distribution of growth stresses in leaning trunks of Cryptomeria japonica (L.f.) D. Don was determined by measuring the stresses released by the kerf method with strain gauges glued at specified positions along the trunks. Effects of both tree height and peripheral positions on the surface of leaning trunks on surface growth stress were determined. The inner residual growth strains in leaning trunks were also measured. We found high compression stresses in the lower side of leaning trunks that differed greatly from the tensile stresses in normal erect trunks. However, transverse compression stress was found around the tree trunk in both normal and compression wood. In leaning trees, the distribution of internal stresses in the bent trunk portion differed from that in the erect trunk portion, being compressive on the outside and tensile on the inside. The resistant moment introduced by compression stress generated in compression wood is released by the bending of the leaning trunk. The bending stresses are then superimposed on the original internal growth stress. We demonstrated that Poisson's effect of longitudinal stresses should be considered when evaluating transverse surface growth stresses. The existence and intensity of compression wood development can be assessed by growth stress measurements. We conclude that the compressing force of compression wood functions physiologically to give an upward righting response in a leaning trunk.

Stress, Mechanical↗

PubMed2001

Cellular membrane-binding ability of the C-terminal cytoplasmic domain of human immunodeficiency virus type 1 envelope transmembrane protein gp41.

The amphipathic alpha-helices located in the cytoplasmic tail of the envelope (Env) transmembrane glycoprotein gp41 of human immunodeficiency virus type 1 have been implicated in membrane association and cytopathicity. Deletion of the last 12 amino acids in the C terminus of this domain severely impairs infectivity. However, the nature of the involvement of the cytoplasmic tail in Env-membrane interactions in cells and the molecular basis for the defect in infectivity of this mutant virus are still poorly understood. In this study we examined the interaction of the cytoplasmic tail with membranes in living mammalian cells by expressing a recombinant cytoplasmic tail fragment and an Escherichia coli beta-galactosidase/cytoplasmic tail fusion protein, both of them lacking gp120, the gp41 ectodomain, and the transmembrane region. We found through cell fractionation, in vivo membrane flotation, and confocal immunofluorescence studies that the cytoplasmic tail contained determinants to be routed to a perinuclear membrane region in cells. Further mapping showed that each of the three lentivirus lytic peptide (LLP-1, LLP-2, and LLP-3) sequences conferred this cellular membrane-targeting ability. Deletion of the last 12 amino acids from the C terminus abolished the ability of the LLP-1 motif to bind to membranes. High salt extraction, in vitro transcription and translation, and posttranslational membrane binding analyses indicated that the beta-galactosidase/LLP fusion proteins were inserted into membranes via the LLP sequences. Subcellular fractionation and confocal microscopy studies revealed that each of the LLP motifs, acting in a position-independent manner, targeted non-endoplasmic reticulum (ER)-associated beta-galactosidase and enhanced green fluorescence protein to the ER. Our study provides a basis for the involvement of the gp41 cytoplasmic tail during Env maturation and also supports the notion that the membrane apposition of the C-terminal cytoplasmic tail plays a crucial role in virus-host interaction.

Animals↗

PubMed2001

Administration of chinese herbal medicines facilitates the locomotor activity in dystrophin-deficient mice.

The purpose of this study was to access the effects of chinese herbal medicines on Duchenne muscular dystrophy (DMD). We use dystrophin-deficient mice (mdx), an animal model of DMD, to evaluate the effect of chinese herbal medicines on locomotor activity. The consumption of water for each mouse was controlled during the three-month experimental session. Each mouse was allowed to drink 3 ml water with or without herbal medicines daily for three months. The estimated intake of chinese herbal medicine in adult mdx mouse with 30 g weight is 100 mg/kg per day, close to a dose used in human. The locomotor activity of the mdx mice was measured every month. Monitoring the locomotor activity of mdx mice after three-month administration of chinese herbal medicines, the results showed that liu-wei-di-huang-wan (LDW) and san-lin-pai-tsu-san (SPS) can facilitate locomotor activity with the parameters of horizontal activity, total distance, number of movements, movement time, vertical activity, number of vertical movements, vertical movement time, stereotypy, number of stereotyped movements, and stereotyped movement time. These results suggest that either LDW or SPS can act as a potent herbal medicine for the pharmacological treatment of DMD patients.

Analysis of Variance↗

PubMed2001

Fructose augments infection-impaired net hepatic glucose uptake during TPN administration.

During chronic total parenteral nutrition (TPN), net hepatic glucose uptake (NHGU) and net hepatic lactate release (NHLR) are markedly reduced (downward arrow approximately 45 and approximately 65%, respectively) with infection. Because small quantities of fructose are known to augment hepatic glucose uptake and lactate release in normal fasted animals, the aim of this work was to determine whether acute fructose infusion with TPN could correct the impairments in NHGU and NHLR during infection. Chronically catheterized conscious dogs received TPN for 5 days via the inferior vena cava at a rate designed to match daily basal energy requirements. On the third day of TPN administration, a sterile (SHAM, n = 12) or Escherichia coli-containing (INF, n = 11) fibrin clot was implanted in the peritoneal cavity. Forty-two hours later, somatostatin was infused with intraportal replacement of insulin (12 +/- 2 vs. 24 +/- 2 microU/ml, SHAM vs. INF, respectively) and glucagon (24 +/- 4 vs. 92 +/- 5 pg/ml) to match concentrations previously observed in sham and infected animals. After a 120-min basal period, animals received either saline (Sham+S, n = 6; Inf+S, n = 6) or intraportal fructose (0.7 mg x kg(-1) x min(-1); Sham+F, n = 6; Inf+F, n = 5) infusion for 180 min. Isoglycemia of 120 mg/dl was maintained with a variable glucose infusion. Combined tracer and arteriovenous difference techniques were used to assess hepatic glucose metabolism. Acute fructose infusion with TPN augmented NHGU by 2.9 +/- 0.4 and 2.5 +/- 0.3 mg x kg(-1) x min(-1) in Sham+F and Inf+F, respectively. The majority of liver glucose uptake was stored as glycogen, and NHLR did not increase substantially. Therefore, despite an infection-induced impairment in NHGU and different hormonal environments, small amounts of fructose enhanced NHGU similarly in sham and infected animals. Glycogen storage, not lactate release, was the preferential fate of the fructose-induced increase in hepatic glucose disposal in animals adapted to TPN.

Animals↗

PubMed2001

Pneumocephalus secondary to septic thrombosis of the superior sagittal sinus: report of a case.

Pneumocephalus secondary to septic superior sagittal sinus thrombosis (SSSST) is extremely rare. We report computed tomography (CT) findings in a 63-year-old man with SSSST caused by the gas-forming organism Klebsiella pneumoniae. The patient presented with fever, chills, general weakness, and spontaneous progressive swelling of the right frontoparietal scalp. CT revealed a gas-containing abscess over the right frontoparietal subgaleal region and in the superior sagittal sinus. Surgical drainage of the subgaleal abscess was performed and blood and pus cultures grew Klebsiella pneumoniae. The patient died of sepsis on the 6th day of hospitalization.

Humans↗

PubMed2001

Aneurysms of the fenestrated basilar artery treated with Gulielmi Detachabe Coils: case report.

Multiple aneurysms at the site of a basilar artery fenestration (BAF) are extremely rare. We report a case of BAF in association with two aneurysms successfully treated with Guglielmi Detachable Coils (GDCs). A 42-year-old male presented with subarachnoid hemorrhage and consciousness change. Angiograms of the vertebrobasilar artery demonstrated fenestration of the proximal basilar artery associated with two aneurysms. Embolization of aneurysms was done by using GDCs. Aneurysms were almost completely obliterated with preservation of the flow and lumen of the vertebrobasilar system. The patient remains asymptomatic at clinical follow-up of 18 months.

Adult↗

PubMed2001

Endovascular embolization of carotid-cavernous fistula using the posterior communicating artery approach: a case report.

We report a case of direct carotid-cavernous fistula complicated with occlusion of internal carotid artery (ICA) at attempted endovascular obliteration via ICA and subsequent successful embolization via the posterior communicating artery (PCoA) approach. After a thorough understanding of vascular anatomical alterations associated with initial technical failure with detachable balloons, a microcatheter was navigated to the fistula site via the vertebro-basilar-PCoA to the distal cavernous segment of the left ICA. Embolization of the fistula was performed with deposition of three platinum microcoils. Angiograms after embolization showed complete disappearance of the fistula. There was no procedural complication and no recurrence of fistula at one-year clinical follow up.

Adult↗

PubMed2001

Image evaluation of suprazygomatic masticator space lesions.

In order to understand lesions involving the suprazygomatic masticator space (SZMS) demonstrated on computered tomography (CT) or magnetic resonance (MR) images, we collected 45 cases of lesions in SZMS. There were hematomas in 26 cases, tumors in 16 cases, and abscesses in 3 cases. The location of these lesions in compartments of the SZMS and adjacent structures was analyzed. Most commonly hematoma was found in the deep loose connective tissue (80.8%), followed by the superficial dense connective tissue (61.5%). Only 2 SZMS hematoma involved the superficial fat pad. Five patients had air accumulation in the SZMS, and all were in the deep fat pad and with maxillary sinus fracture. Of the sixteen cases which were tumors, 12 were extended from adjacent structures, and four were primary tumor. In cases of tumor, compartments of SZMS involved most frequently were temporal muscles (15 of 16 cases), followed by deep fat pad (8 of 16 cases). The connective tissue layer of SZMS is a communication pathway for superficial spread of infection, hematoma, or tumor invasion to or from the scalp and face. Compartments of deep fat pad and temporal muscle are also pathways for the spread of disease to or from the face, intracranium and orbit. The primary tumors in infratemporal fossa and SZMS are rare. Malignant tumors in SZMS usually come from surrounding spaces.

Adolescent↗

PubMed2001

Sequential MR studies of a patient with white matter disease presenting psychotic symptoms: ADEM versus single-episode MS.

Acute disseminated encephalomyelitis (ADEM) and multiple sclerosis (MS) are both demyelinating white matter disorders. It is difficult to differentiate ADEM from single episode MS because of the similar clinical presentation, cerebral spinal fluid (CSF) analysis, histological finding and magnetic resonance image (MRI) appearance. We report an ADEM case with unusual clinical presentations of predominant psychiatric symptoms, and relatively long disease course. Initially, we were not able to distinguish it from single episode MS. By means of sequential MR images followed up 2 years and spectroscopy studies, and the dramatic clinical improvement after corticosteroid therapy, ADEM was diagnosed as the disease entity of this patient. In this case report we will present the MR findings of this patient and discuss the differentiation between the ADEM and MS.

Adult↗

PubMed2001

Percutaneous transluminal angioplasty as an adjunct to treat the carotid-cavernous fistula.

We report a case of the direct carotid-cavernous fistula (CCF) with high-grade stenosis of the internal carotid artery (ICA) and treatment via the transarterial route after percutaneous transluminal angioplasty (PTA). A 46-year-old man was found to have a CCF after a motorcycle accident. Transarterial embolization was attempted, but it failed due to stenosis of the left cervical ICA. After the procedure of PTA for dilatation of the stenotic ICA, the fistula was successfully obliterated by detachable balloon subsequently. There were no complications or recurrence of the fistula at the three-year clinical follow up.

Angioplasty, Balloon↗

PubMed2001

Magnetic resonance imaging appearance of intradural spinal lipoma.

Intradural spinal lipoma not associated with spinal dysraphism is a rare tumor often presenting with nonspecific symptoms and indolent clinical course. Its intradural location and fat component is the key for proper preoperative diagnosis, which could hardly be made by traditional imaging studies including plain film and myelography. Both CT and MRI can reveal the fat component of the tumor, but MRI is superior to CT in demonstrating its relationship with adjacent normal nerve tissue. We report a 32-year-old man who had back pain for years and the symptom progressed rapidly in recent two months. MRI revealed an intradural tumor at T12 level with high signal intensity on both T1- and T2-weighted images. The signal intensity dropped dramatically with fat saturation technique, which confirmed fat as its main component. The patient received surgery and the tumor was proved to be an intraspinal lipoma.

Adult↗