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Biomedical subjects

S J Song

Publications and source records attributed to S J Song.

At least 19 recordsLinked to original sources
PubMed2006

Temporal expression of proteoglycans in the rat limb during bone healing.

Proteoglycans found in the bone extracellular matrix and on the cell surface can complex with HBGFs such as the FGFs, TGFs and BMPs which are known to play key roles in regulating fracture healing. Here we have studied the expression of key PGs during the bone repair process in order to determine the relationship between PG expression and healing status. We created non-critical sized trephine defects just proximal to the distal end of the tibial crest of adult male Wistar rats and examined the healing process histologically as well as by monitoring the temporal expression of mRNA transcripts for ALP, OP and OC, together with HSPG, CSPG and FGF-FGF receptor expression. Following surgery, animals were allowed to recover, and then euthanized after 7, 14, 21 and 28 days post-surgery, at which time tissue was harvested for histological examination and total RNA extracted and the mRNA transcripts examined by quantitative real-time PCR. HS and CSPG expression was generally observed to increase in the days immediately following injury, reaching peak expression two weeks post-surgery. This was followed by a gradual return to basal levels by day 28. The expression patterns of PGs were broadly similar with those of ALP, OP and FGFRs. The increase of mRNA expression for many key PGs detected during bone healing coincided with the elevation of bone markers and FGFRs, and provides further evidence that PGs involved in bone repair act in part through susceptible growth factors, including the FGF/FGFR system. The data presented here indicates that increased proteoglycan expression is involved in the early stages of bone healing at a time when previous studies have shown that the levels of HBGFs are maximal. Hence there exists a rationale for an exploration of the use of exogenous PGs as an adjunct therapy to potentiate the powerful effects of these factors and to augment the natural healing response.

Animals↗
PubMed2005

Secondary insults and outcomes in patients with hypertensive basal ganglia hemorrhage.

This study was designed to monitor secondary insults and their impact on outcomes of patients with hypertensive basal ganglia hemorrhage (HBGH). One hundred and twelve patients with HBGH (male 73, female 39) of age 42 +/- 8 years (range from 38 to 57 years) were studied. Operations included craniotomy or trephination drainage with urokinase thrombolysis. Conventional therapies were also given to the patients including the administration of mannitol, crystalloid and colloid solution. In the meantime, blood pressure (MAP), temperature (T) and SaO2 and other parameters were recorded in the intensive care unit. The ICP values were recorded, and the early clinical outcome was assessed upon discharge according to Glasgow Outcome Scale. Cerebral Perfusion Pressure was calculated as CPP = MAP-MICP. Outcomes in the group without secondary insults were better than that in the group with secondary insults (P < 0.01). No unfavorable outcomes were found in the 59 cases managed by ultra-early surgery whereas 36.1% of the cases operated after 6 hours of onset had unfavorable outcomes. It is concluded that the high incident rate of secondary insults in HICH patients influences outcome. Ultra-early surgery may also contribute to improved quality of survival.

Adult↗
PubMed2005

Studies on the receptors mediating responses of osteoblasts to thrombin.

The serine protease thrombin stimulates proliferation in osteoblasts, but decreases alkaline phosphatase (ALP) activity, a marker of osteoblast differentiation. Three thrombin receptors have been identified, protease activated receptor (PAR)-1, PAR-3 and PAR-4; we have previously demonstrated that mouse osteoblasts express PAR-1 and PAR-4. The effect of thrombin on osteoblast proliferation and differentiation was studied to determine which of the thrombin receptors is responsible for the primary effects of thrombin. Primary mouse calvarial osteoblasts from PAR-1-null and wild-type mice, and synthetic peptides that specifically activate PAR-1 (TFFLR-NH2) and PAR-4 (AYPGKF-NH2) were used. Both the PAR-1-activating peptide and thrombin stimulated incorporation of 5-bromo-2'-deoxyuridine (two to four-fold, P < 0.001) and reduced alkaline phosphatase activity (approximately three-fold, P < 0.05) in cells from wild-type mice. The PAR-4-activating peptide, however, had no effect on either alkaline phosphatase activity or proliferation in these cells. Neither thrombin nor PAR-4-activating peptide was able to affect osteoblast proliferation or alkaline phosphatase activity in cells isolated from PAR-1-null mice. The results demonstrate that thrombin stimulates proliferation and inhibits differentiation of osteoblasts through activation of PAR-1. No other thrombin receptor appears to be involved in these effects.

Animals↗
PubMed2005

Four peptide hormones' specific decrease (up to 97%) of human prostate carcinoma cells.

BACKGROUND: Mortality from prostate cancer remains a significant problem with current treatment(s), with an expected 30 350 deaths from prostate cancer in 2005. Long-acting natriuretic peptide, vessel dilator, kaliuretic peptide and atrial natriuretic peptide have significant anticancer effects in breast and pancreatic adenocarcinomas. Whether these effects are specific and whether they have anticancer effects in prostate adenocarcinoma cells has not been determined. MATERIALS AND METHODS: These peptide hormones were evaluated to determine if they have specific anticancer effects in human prostate adenocarcinomas. RESULTS: Dose-response curves revealed a significant (P < 0.05) decrease in human prostate cancer number with each tenfold increase in the concentration from 1 microM to 1000 microM (i.e. 1 mM) of these four peptide hormones. There was a 97.4%, 87%, 88% and 89% (P < 0.001 for each) decrease in prostate cancer cells secondary to vessel dilator, long-acting natriuretic peptide, kaliuretic peptide and atrial natriuretic peptide, respectively, at their 1-mM concentrations within 24 h, without any proliferation in the 3 days following this decrease. These same hormones decreased DNA synthesis from 68% to 89% (P < 0.001). When utilized with their respective antibodies their ability to decrease prostate adenocarcinoma cells or inhibit their DNA synthesis was completely blocked. Western blots revealed that for the first time natriuretic peptide receptors (NPR) A- and C- were present in prostate cancer cells. CONCLUSIONS: These results indicate that these peptide hormones' anticancer effects are specific. Furthermore, they have very potent effects of eliminating up to 97% of prostate cancer cells within 24 h of treatment.

Adenocarcinoma↗
PubMed2005

Total knee arthroplasty in stiff knees after previous infection.

Between July 1986 and August 1996, we performed 32 total knee arthroplasties (TKA) on 32 patients with partially or completely ankylosed knees secondary to infection. Their mean age at surgery was 40 years (20 to 63) and the mean follow-up was ten years (5 to 13). The mean post-operative range of movement was 75.3 degrees (30 to 115) in those with complete and 98.7 degrees (60 to 130) in those with partial ankylosis. The mean Hospital for Special Surgery knee score increased from 57 to 86 points post-operatively. There were complications in four knees (12.5%), which included superficial infection (one), deep infection (one), supracondylar femoral fracture (one) and transient palsy of the common peroneal nerve (one). Although TKA in the ankylosed knee is technically demanding and has a considerable rate of complications, reasonable restoration of function can be obtained by careful selection of patients, meticulous surgical technique, and aggressive rehabilitation.

Adult↗
PubMed2004

Catalyzed ozonation process with GAC and metal doped-GAC for removing organic pollutants.

The purpose of this study was to investigate the catalytic role of granular activated carbon (GAC), and metal (Mn or Fe) doped-GAC, on the transformation of ozone into more reactive secondary radicals, such as hydroxyl radicals (*OH), for the treatment of wastewater. The GAC doped with Mn showed the highest catalytic performance in terms of ozone decomposition into OH radicals. Likewise, activated carbon alone accelerated the ozone decomposition, resulting in the formation of *OH radicals. In the presence of promoters, the ozone depletion rate was enhanced further by the Mn-GAC catalyst system, even under aqueous acidic pH conditions.

Carbon↗
PubMed2002

Protease-activated receptors: a means of converting extracellular proteolysis into intracellular signals.

Protease-activated receptors (PARs) mediate cellular responses to a variety of extracellular proteases. The four known PARs constitute a subgroup of the family of seven-transmembrane domain G protein-coupled receptors and activate intracellular signalling pathways typical for this family of receptors. Activation of PARs involves proteolytic cleavage of the extracellular domain, resulting in formation of a new N terminus, which acts as a tethered ligand. PAR-1, -3, and -4 are relatively selective for activation by thrombin whereas PAR-2 is activated by a variety of proteases, including trypsin and tryptase. Recent studies in mice genetically incapable of expressing specific PARs have defined roles for PAR-1 in vascular development, and for PAR-3 and -4 in platelet activation, which plays a fundamental role in blood coagulation. PAR-1 has also been implicated in a variety of other biological processes including inflammation, and brain and muscle development. Responses mediated by PAR-2 include contraction of intestinal smooth muscle, epithelium-dependent smooth muscle relaxation in the airways and vasculature, and potentiation of inflammatory responses. The area of PAR research is rapidly expanding our understanding of how cells communicate and control biological functions, in turn increasing our knowledge of disease processes and providing potential targets for therapeutic intervention.

Animals↗
PubMed2001

Five saponins from the root bark of Aralia elata.

Five saponins, 3-O-[beta-D-glucopyranosyl (1-->2)-[beta-D-glucopyranosyl (1-->3)]-beta-D-glucopyranosyl]-oleanolic acid 28-O-beta-D-glucopyranosyl ester (aralia-saponin V), 3-O-[beta-D-glucopyranosyl (1-->2)-[beta-D-glucopyranosyl (1-->3)]-beta-D-glucopyranosyl]-echinocystic acid 28-O-beta-D-glucopyranosyl ester (aralia-saponin VI), 3-O-beta-D-glucopyranosyl (1-->2)-[beta-D-glucopyranosyl (1-->3)]-beta-D-glucopyranosyl]-hederagenin 28-O-beta-D-glucopyranosyl ester (aralia-saponin VII), 3-O-[beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-beta-D-glucopyranosyl]-caulophyllogenin 28-O-beta-D-glucopyranosyl ester (aralia-saponin VIII), 3-O-[beta-D-glucopyranosyl (1-->2)-[beta-D-glucopyranosyl(1-->3)]-alpha-L-arabinopyranosyl]-hederagenin 28-O-beta-D-glucopyranosyl ester (aralia-saponin IX), were isolated from the root bark of Aralia elata (Miq.) Seem., together with four known compounds. Their structures were determined on the basis of chemical and spectroscopic methods.

Magnoliopsida↗
PubMed2001

Partial characterization of farnesyl and geranylgeranyl diphosphatases induced in rice seedlings by UV-C irradiation.

This study reports the identification and characterization of allyl diphosphatases (EC 3.1.7.1) in plants by using rice seedlings. Two distinct Mg(2+)-independent allyl diphosphatases, which convert farnesyl diphosphate (FDP) and geranylgeranyl diphosphate (GGDP) into farnesol and geranylgeraniol, respectively, were induced in rice seedlings irradiated with UV-C. Farnesyl diphosphatase (FDPase) and geranylgeranyl diphosphatase (GGDPase) are located in the microsomal fraction. The relative specific activity of FDPase was much higher than the specific activity of GGDPase. FDPase activity was inhibited by GGDP (50% inhibition at 5 microM) and geranyl diphosphate (50% inhibition at 100 microM). In contrast, GGDPase activity was inhibited 50% by 50 microM isopentenyl diphosphate or 100 microM FDP. The optimal pH for FDPase was 6.3 and for GGDPase was 7.9.

Farnesol↗
PubMed2001

Outcome following addition of peroneus brevis tendon transfer to treatment of acquired posterior tibial tendon insufficiency.

The flexor digitorum longus, the tendon most often used for transfer in posterior tibial tendon insufficiency, is one-half to one-third the size of the posterior tibial tendon. Occasionally it may be particularly small or may have been previously used for transfer. In these cases, the senior author has felt that the addition of a transfer of the Peroneus Brevis (PBr) tendon may be helpful in maintaining sufficient tendon and muscle mass to rebalance the foot. Thirteen patients who underwent this procedure were retrospectively identified and matched by age and length of follow-up to patients who underwent a more standard tendon transfer operation minus the addition of the PBr transfer. Pain and functional status were then assessed by the American Orthopaedic Foot and Ankle Society's ankle/hindfoot rating scale. Each patient was tested by an independent physical therapist to evaluate inversion and eversion strength. The mean duration of follow-up was 20.6 months (12 to 34 months). The average AOFAS score of the PBr group was 75.8 compared to 71.5 for the standard control group. There was no significant difference between the groups when inversion or eversion strengths were compared. Inversion strength and eversion strength was rated good or excellent (4 or 5) in 12 out of 13 of the PBr transfer group patients. No major complications were encountered in either group. Although it does not increase inversion strength, a PBr transfer can be used to augment a small FDL without causing significant eversion weakness. This can be useful when the FDL is particularly small or in revision surgery.

Calcaneus↗
PubMed2000

Deltoid ligament strain after correction of acquired flatfoot deformity by triple arthrodesis.

Deltoid insufficiency represents a difficult surgical challenge. We have witnessed patients who have developed a valgus tibiotalar deformity following a properly positioned triple arthrodesis. To investigate whether the triple arthrodesis itself, by creating a rigid triple joint complex below the ankle, leads to increased strain of the deltoid complex, a flatfoot model was created in 8 fresh-frozen below-knee amputation specimens. Each specimen was loaded in three gait cycle (GC) positions: Heel strike (0% GC), midstance (10% GC), and heel rise (40% GC). The three components of the ground reaction force (GRF) and the tendon forces consistent with those respective positions were applied. To simulate a posterior tibial tendon insufficient state the posterior tibial tendon was not loaded. Strain at the tibiocalcaneal fibers of the superficial deltoid ligament complex was determined at each of the three foot positions. A triple arthrodesis was performed and the deltoid strains were again recorded for each position. A significant increase in the strain of the deltoid ligament was observed for only the heel rise position (p=0.007) in our cadaver model following triple arthrodesis. The results favor medializing the calcaneus following arthrodesis to protect the deltoid complex.

Adult↗
PubMed2000

Four new saponins from the root bark of Aralia elata.

Four new saponins, 3-O-[beta-D-glucopyranosyl(1-->3)-alpha-L-arabinopyranosyl]-16a lpha-hydroxyoleanolic acid 28-O-beta-D-glucopyranosyl ester (called aralia-saponin I), 3-O-[beta-D-glucopyranosyl(1-->3)-alpha-L-arabinopyranosyl]-16a lpha-hydroxyhederagenin 28-O-beta-D-glucopyranosyl ester (aralia-saponin II), 3-O-[beta-D-glucopyranosyl(1-->3)-beta-D-glucopyranosyl(1-->3)-alpha-L-+ ++arabinopyranosyl]-16alpha-hydroxyoleanolic acid 28-O-beta-D-glucopyranosyl ester (aralia-saponin III), 3-O-[beta-D-glucopyranosyl(1-->3)-beta-D-gucopyranosyl(1-->3)-beta -D-glucucopyranosyl]-16alpha-hydroxyoleanolic acid 28-O-beta-D-glucopyranosyl ester (aralia-saponin IV), were isolated from the root bark of Aralia elata (Miq.) Seem., together with nineteen known compounds including glycosides of (20S)-protopanaxadiol and (20S)-protopanaxatriol. Their structures were determined on the basis of chemical and spectroscopy methods.

Carbohydrate Conformation↗
PubMed1998

A second look at the embryotoxicity of hydrosalpingeal fluid: an in-vitro assessment in a murine model.

The purpose of this study was to evaluate whether hydrosalpingeal fluid (HSF) is toxic to the mouse embryo as assessed by the blastocyst development rate (BDR) and by cell counting in vitro. HSF was collected from nine patients undergoing salpingoneostomy to correct hydrosalpinx. Two-cell embryos were obtained from superovulated ICR mice. T6 medium and T6 + 0.4% bovine serum albumin (BSA) were used as control media. T6 medium containing 10% or 50% HSF and 100% HSF from each patient were used as test media. Nine to 15 embryos were cultured in microdrops prepared from each of these media. The BDR was examined after 72 h of culture in these media. To assess the total cell number within each blastocyst, the blastocysts were fixed and stained with Hoechst 33342 to facilitate cell counting. The BDR was affected adversely only by 100% HSF and not in media containing 10% or 50% HSF. The mean BDR using T6 medium and T6 + BSA were 88.7% and 85.3%, respectively. The mean BDR using media containing 10% HSF or 50% HSF were 90.0% and 89.4%, respectively. Mean BDR using 100% HSF was 75.2% (P < 0.05). The overall mean cell counts (+/- SEM) using T6 medium and T6 + BSA were 86.9+/-3.2 and 91.0+/-3.8 respectively. Mean cells counts were decreased significantly only in blastocysts cultured in 100% HSF (63.3+/-4.6; P < 0.01) but not in blastocysts cultured in 10% or 50% HSF (90.8+/-4.2 and 81.9+/-6.1 respectively). Thus, it is concluded that HSF has no embryotoxic effect but has a mildly negative effect on embryonic growth and development.

Animals↗
PubMed1995

Aspects of musculoskeletal magnetic resonance imaging.

MRI can clearly identify many pathological processes in the musculoskeletal system. Because it is a non invasive investigation, it plays an important role in assessing joint pathology and musculoskeletal masses prior to any interventional procedure. If used properly, it can be cost effective and redundant diagnostic tests can be reduced, appropriate therapy can be instituted and unnecessary surgical intervention and hospitalisation can be avoided.

Humans↗
PubMed1994

[An immunohistochemical study on megakaryocytes in patients with myelodysplastic syndromes].

An immunohistochemical study was performed on trephine biopsy specimens of bone marrow in 10 patients with myelodysplastic syndromes (MDS). Monoclonal antibodies HIP7 and CDW41 were used against platelet glycoprotein IIb/IIIa (CD41) to determine dysmegakaryopoiesis including its size, proportion of micromegakaryocytes, location and staining characteristics. The results show that the dysmegakaryopoiesis of MDS includes the increased number and high proportion of micromegakaryocytes, the altered architectural distribution and the considerable variation in staining. These may be helpful in the diagnosis and differential diagnosis of MDS.

Bone Marrow↗
PubMed1993

[Bone metabolism in postmenopausal women and after estrogen treatment].

Changes of bone metabolism in 11 premenopausal women and 109 postmenopausal women were studied. 50 postmenopausal women were randomly divided into 4 groups: 20, 10 and 6 cases were given nylestriol, diethyl stilbestrol and chlorotrianisen respectively, and 14 cases served as control. It was shown that bone mineral content (BMC), and, blood estrogen level in postmenopausal women were significantly lower than those of premenopausal women. Close correlation existed between E1, E2, and BMC. Serum alkaline phosphatase (ALP), bone GLA protein (BGP), urine Ca/Cr and Hpr/Cr were markedly increased in postmenopausal women and declined after 3 months of treatment with nylestriol, diethylstilbestrol or chlorotrianisen. The radial BMC increased by 0.8% with (P > 0.05) nylestriol treatment for one year and decreased by 1.1% (P < 0.05) in the control cases. The present study indicated that postmenopausal estrogen deficiency accelerated bone loss, which was prevented by small substitution doses of estrogen such as nylestriol.

Bone Density↗
PubMed1989

Cytophotometric assessment of T-2 toxin induced alterations in azure B-RNA and Coomassie-protein in supraoptic-magnocellular neurons of rat hypothalami.

Quantitative cytophotometry was used to monitor T-2 toxin-induced alterations in azure B-RNA and Coomassie-total cell protein in supraoptic-magnocellular neurons of rat hypothalami. Thirty male Sprague-Dawley rats (200-220g) were given a single i.p. injection of T-2 toxin (0.5, 0.75, 1.00 and 1.50 x LD50), a trichothecene mycotoxin; rats were decapitated 8 hours post-dosing. After stoichiometric azure B-RNA and Coomassie-protein staining of brain sections, scanning-integrating microdensitometry was used to quantify toxin-induced alterations in these well established indices of neuronal toxicity. Within the magnocellular neurons of the supraoptic nuclei, significant reductions in azure B-RNA reactivity were observed in the 0.75, 1.00 and 1.50 x LD50 groups (i.e. 11%, 13% and 8%, respectively); no differences in RNA levels were observed between controls and the 0.50 x LD50 group. In addition, a decrease in Coomassie-total cell protein was seen in animals receiving 0.50, 0.75 and 1.50 x LD50 T-2 toxin (i.e. 33%, 21% and 12%, respectively); however, toxin administration did not alter protein levels in the 1.00 x LD50 group. Furthermore, a dose-dependent decrease in systolic blood pressure was observed at 8 hr. post-injections (i.e., approximately -39%, -52%, -66% and -64% for the 0.50, 0.75, 1.00 and 1.50 x LD50 groups, respectively). Additional observations include pronounced polydipsia, ascites, abdominal and subdural hemorrhage, and horripilation (piloerection) in experimental groups. It is postulated that the T-2 toxin-induced reductions in azure B-RNA and Coomassie-protein represent an early indication of impaired metabolic activity. Since these neurons are important sites of vasopressin (antidiuretic hormone) synthesis, these data suggest an impaired osmoregulatory ability. The pronounced polydipsia which occurred shortly after intoxication is further evidence of this impairment. Although these findings do not provide insight relating to the mechanism of osmoregulatory disruption, it is advanced that the supraoptic-magnocellular compartment represents an important site in T-2 toxin mycotoxicosis. Moreover, these findings support previous claims that T-2 toxin intoxication may critically impair the vasopressinergic response to toxin-induced cardiovascular collapse.

Animals↗