Monoclonal antibody against the platelet glycoprotein (GP) IIb/IIIa receptor prevents coronary artery reocclusion after reperfusion with recombinant tissue-type plasminogen activator in dogs

Localized thrombosis was produced in the left anterior descending (LAD) coronary artery of open chest dogs by constricting a segment so as to produce greater than 90% stenosis (reducing blood flow to 40 +/- 10% of baseline), and placing a thrombus in the segment immediately proximal to the stenosis by inducing endothelial cell injury and instilling a mixture of blood and thrombin. Intravenous infusion of recombinant tissue-type plasminogen activator (rt-PA) at a rate of 15-30 micrograms/kg per min for 30 or 60 min in eight dogs induced coronary artery reperfusion within 23 +/- 7 min (mean +/- SD), but reocclusion occurred despite heparin anticoagulation in all but one of these dogs within 7 +/- 5 min. Intravenous injection of 0.8 mg/kg of the F(ab')2 fragment of a monoclonal antibody (7E3) directed against the platelet GPIIb/IIIa receptor, prevented reocclusion in 10/10 dogs during an observation period of 2 h (P less than 0.001 vs. rt-PA alone). The antibody abolished ADP-induced platelet aggregation and markedly prolonged the bleeding time. Intravenous aspirin or dipyridamole prevented reocclusion for 1 h or more in only 2/7 and 1/6 dogs, respectively. We conclude that the monoclonal antibody is very effective in preventing reocclusion after successful thrombolysis of occluded coronary arteries with rt-PA.

Scintigraphic quantification of myocardial necrosis in patients after intravenous injection of myosin-specific antibody

The Fab fragments of antimyosin antibodies, labeled with 99mTc, were used in the scintigraphic examination of 30 patients with myocardial infarction. The ability to detect necrosis and determine its extent from the antimyosin scan were compared with the results of quantitative regional wall motion analysis by contrast ventriculography at 10 to 14 days and 99mTc-pyrophosphate imaging. Antimyosin images recorded by planar and single photon-emission computed tomography (SPECT) delineated areas of myocardial necrosis in 27 of 30 patients (90%) compared with a 91% sensitivity of pyrophosphate in 21 of 23 patients. Infarct size was determined by both antimyosin and pyrophosphate SPECT images. Results by both techniques showed a significant correlation with computer-derived hypokinetic segment length (r = .79 for both, p = .002) and peak creatine kinase (r = .9 for both, p less than .01). Although sensitivity for and correlations with markers of necrosis were similar with both techniques, infarct size by pyrophosphate SPECT was 1.7 times larger than infarct size by antimyosin SPECT (p less than .01). Certain zones in the infarct area were differentially labeled; the nature and irreversibility of injury within these zones remains to be clarified.

Porous biodegradable microspheres for controlled drug delivery. I. Assessment of processing conditions and solvent removal techniques

Microspheres containing methylene blue and prednisolone acetate were prepared by one of three methods: freeze-drying, evaporation, and solvent-extraction-precipitation. An extremely porous structure was obtained by the freeze-dry and solvent-extraction-precipitation procedures. The specific surface area of 6.33-microns particles was 20.6 m2/g, or 35 times that of a particle devoid of pores, and the void space was 59-61%. The sphericity, size, and yields of the microspheres were influenced by the preparation procedure, surfactant type and concentration, temperature of the continuous phase, polymer concentration in the dispersed phase, and ratio of marker to polymer. The most suitable processing conditions were a polymer concentration of 5-10%, a marker loading of 10%, 0.1% sorbitan sesquioleate as the surfactant, and temperature adjustment of the continuous phase from 15 to 50 degrees C following the addition of the dispersed phase. Complete release of the highly water soluble methylene blue occurred within 72 hr, while the less soluble prednisolone acetate released much more slowly, i.e., 90% after 7 days. The microspheres remained relatively intact during the in vitro release of methylene blue, confirming that the incorporated agent was confined to the walls of the porous network. Collapse of the polymer structure was evident after 7 days. The release therefore was believed to be governed principally by the solubility of the drug and the porosity of the matrix.

Clinical significance of expression of membrane type 1 matrix metalloproteinase and matrix metalloproteinase-2 in human head and neck squamous cell carcinoma

Three different membrane-type matrix metalloproteinases (MT-MMPs) activate in vitro the latent form of matrix metalloproteinase-2 (MMP-2), which is one of the key proteinases in invasion and metastasis of various cancers. We examined the mRNA expression of MT1, 2, and 3-MMPs and MMP-2 in cell lines of head and neck squamous cell carcinoma (HNSCC) and quantitated the relative expression levels in human HNSCC tissues by Northern blotting. The tissue localization of MT1-MMP and MMP-2 was determined by immunohistochemistry and in situ hybridization. Their implications in clinicopathologic factors were statistically evaluated. All cell lines examined consistently expressed MT1-MMP and MMP-2, but not MT2, 3-MMP. In the clinical specimens, there was a significant correlation in coexpression of messenger of RNA (P = .0005) and colocalization by immunohistochemistry (P < .0001) for MT1-MMP and MMP-2. Relative mRNA expression levels of MT1-MMP and MMP-2 in the carcinoma tissues were significantly higher than those of the control tissues (P = .0045 and P = .0122, respectively). Both mRNA expression level and immunopositivity of MT1-MMP significantly correlated with lymph node metastasis (P = .0081 and P = .0193, respectively), which was confirmed by multivariate logistic regression analysis. Immunoreaction of MT1-MMP and its mRNA expression were observed in both carcinoma cells and stromal cells. The localization of MMP-2 closely corresponded to that of MT1-MMP. These observations suggest that MT1-MMP possesses a role as a determinant of lymph node metastasis in HNSCC, and that concurrent expression of MT1-MMP and MMP-2 are involved in progression of HNSCC.

Acute hemodynamic effects and blood pool kinetics of polystyrene microspheres following intravenous administration

The acute hemodynamic effect of intravenous administration of polystyrene microspheres was investigated and correlated with their distribution pattern and kinetics. Microspheres of three diameters (3.4, 7.4, and 11.6 micrometer) were administered. The 7.4- and 11.6-micrometer diameter microspheres were filtered by the pulmonary capillary network following intravenous administration, the majority during the first pass. There was no significant hemodynamic effect following administrations of the 7.4- and 11.6-micrometer diameter microspheres in doses as high as 3.0 X 10(9) and 6.1 X 10(8) respectively (total cross-sectional area of 1.3 X 10(11) and 6.4 X 10(10) micrometer2, respectively). Intravenous administration of 3.4-micrometer diameter microspheres produced significant dose-dependent systemic hypotension and depression of myocardial performance at dosages as slow as 1.0 X 10(10) (cross-sectional area of 9.1 X 10(10) micrometer2). These differences in acute hemodynamic effect from the 7.4- and 11.6-micrometer diameter microspheres may be due to the differences in distribution kinetics and fate of the 3.4-micrometer diameter microspheres, which readily pass through the lungs to the spleen. Although elimination of the smaller spheres from the blood during the first 6-8 min was rapid, i.e., t 1/2 = 1.62 and 1.72 min from the venous and arterial blood circulation, respectively, levels of 10(3) spheres/g of blood were present in the circulation for greater than 1 hr. These findings must be considered in the planning of intravenous administration of microspheres as a drug delivery system to target organs.

Application of curdlan to controlled drug delivery. III. Drug release from sustained release suppositories in vitro

The use of curdlan, a natural beta-1,3-glucan, in the preparation of sustained release suppositories was studied in vitro. To prepare the suppositories, indomethacin, prednisolone or salbutamol sulfate was mixed with curdlan gel. Preparation conditions, including heating time and curdlan concentrations of 5 and 10%, had little effect on the drug release. The tonicity (hypotonic or isotonic) of the media for the suppository preparation and for in vitro drug release study also had little effect on drug release. However, the heating temperature during gel preparation, the drug amount in the suppository and the type of release media did affect drug release. It was found that drug release was sustained and diffusion-controlled in the three drugs. And finally, curdlan can be applicable for use in a sustained release suppository.

Granulocyte-macrophage colony-stimulating factor upregulates matrix metalloproteinase-2 (MMP-2) and membrane type-1 MMP (MT1-MMP) in human head and neck cancer cells

Matrix metalloproteinase-2 (MMP-2) and membrane type 1-MMP (MT1-MMP) play an important role in the invasion and metastasis of head and neck squamous cell carcinoma (HNSCC), but the mechanism of their regulation is not clearly understood. Recently, granulocyte-macrophage colony-stimulating factor (GM-CSF) has been shown to be associated with cancer invasion and metastasis. We hypothesized that GM-CSF may upregulate MMP-2 and/or MT1-MMP expression in HNSCC cells, and may thereby influence their ability to invade and metastasize. We studied the effects of GM-CSF on the production of MMP-2 and MT1-MMP in HNSCC cell lines SAS and HSC-2. Gelatin zymography of conditioned media derived from HNSCC cells revealed a major band of 68 kDa, which was characterized as proMMP-2. GM-CSF stimulated the production of proMMP-2 in both cell lines in a dose-dependent manner. Treatment with 50 ng/ml GM-CSF for 24 h increased the proMMP-2 activity 3.4-fold in SAS cells and 2.3-fold in HSC-2 cells compared with untreated controls. Northern blot analyses demonstrated that GM-CSF led to elevated mRNA levels of MMP-2 and MT1-MMP in both cell lines. The results identify GM-CSF as a regulator of MMP-2 and MT1-MMP expression in certain types of HNSCC, and suggest that GM-CSF may contribute to the invasiveness of HNSCC through the regulation of MMP-2 and MT1-MMP expression.

Role of CD44 variant exon 6 in invasion of head and neck squamous cell carcinoma

OBJECTIVES

To determine the correlation between the expression of CD44 variant exon 6 (v6) and the clinicopathological features of head and neck squamous cell carcinomas (HNSCCs), and to study the role of CD44v6 in cell invasion using a human HNSCC cell line (HSC-2).

DESIGN

The expression of CD44v6 was evaluated using immunohistochemical analysis in paraffin-embedded tissue specimens from 89 primary lesions. The concentration of CD44v6 protein in 37 cryopreserved tumor specimens was evaluated using the enzyme-linked immunosorbent assay. The HSC-2 cells were treated with 2F10, a monoclonal antibody against CD44v6. The effects of 2F10 on HSC-2 cell proliferation, migration, and invasion potential were evaluated.

RESULTS

The down-regulation of CD44v6 expression or the concentration of cancer tissue significantly correlated with a lower degree of pathohistological differentiation and a higher rate of cervical metastasis. The invasion of HSC-2 cells into type I collagen gel and the expression of CD44v6 were decreased in invading cells released from the upper layer. Furthermore, the treatment of HSC-2 cells with 2F10 significantly enhanced cell invasion. However, 2F10 did not affect either the proliferation or migration properties of HSC-2 cells.

CONCLUSIONS

The down-regulation of CD44v6 expression may be useful as a biological marker for the degree of malignancy in HNSCCs. We assume that the loss or dysfunction of CD44v6 is involved in the acquisition of invasion ability in HSC-2 cells. In addition, the potential existence of a CD44v6-mediated signal transduction pathway may play a role in inhibiting the invasion in HNSCCs.

The effect of fosfomycin on glycopeptide antibiotic-induced nephrotoxicity in rats

The effect of coadministration of fosfomycin (FOM) on glycopeptide antibiotic-induced nephrotoxicity for 3 days was investigated in rats. To induce nephrotoxicity in a short time, gentamicin (GM) was also coadministered. In the present study, FOM decreased glycopeptide antibiotic-induced nephrotoxicity as shown by reduced urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG) as well as fewer histopathological signs of nephrotoxicity in the groups treated with the combination of glycopeptide and FOM as compared with a glycopeptide alone. In addition, the higher the dose of FOM, the more it decreased urinary NAG levels, suggesting that the role of FOM in alleviating nephrotoxicity is dose dependent. The accumulation of teicoplanin and vancomycin was significantly lower in the renal cortex of rats treated with the combination of glycopeptide antibiotics and FOM as compared with glycopeptide antibiotics alone (P < 0.05). In conclusion, the concomitant administration of FOM and glycopeptide antibiotics may help to achieve a chemotherapeutic strategy that reduces the nephrotoxic effects of glycopeptide antibiotics.

Application of curdlan to controlled drug delivery. I. The preparation and evaluation of theophylline-containing curdlan tablets

To study the use of curdlan, a natural beta-1,3-glucan, in drug delivery, in vitro release studies were carried out with curdlan tablets containing theophylline. Tablets were readily prepared by compressing three different curdlan and theophylline mixtures, namely, a physical mixture, spray-dried curdlan particles with theophylline powder, and spray-dried particles of curdlan/theophylline solution. Drug release from the tablets prepared from spray-dried particles of curdlan/theophylline was lowest. The release rate was constant from 1 to 8 hr, and 59% cumulative release was obtained at 8 hr. Drug release from curdlan tablets was unaffected by pH or various ions; these curdlan tablets might also control drug release in vivo after oral administration. Application of Higuchi's equation indicated that drug release from curdlan tablets was diffusion-controlled. The release profiles of the curdlan tablets were compared to those of a commercial theophylline sustained-release tablet.

Protective effects of sodium-L-ascorbyl-2 phosphate on the development of UVB-induced damage in cultured mouse skin

The protective effect of sodium-L-ascorbyl-2 phosphate (As-2P), a stable form of ascorbic acid (AsA), against photodamage induced by a single dose of UVB exposure (290-320 nm, Max 312 nm) was investigated using cultured mouse skin. When the cultured skin was treated with various As-2P concentrations, the cutaneous AsA level increased in proportion to the As-2P concentration. After 3 h of incubation, the AsA level in the cultured skin treated with 2, 20 and 100 mM As-2P increased 1.03-, 2.17- and 6.27-fold, respectively, compared with that of the control skin. These results suggest that As-2P was transported into the cultured mouse skin where it was converted to AsA. After 3 h, the cutaneous AsA level in irradiated (20 kJ/m2) skin was depleted to a half of that in the control skin. However, the level in skin pretreated with 20 mM As-2P was maintained within normal limits, even after 24 h. Pretreatment with 20 mM As-2P significantly prevented such photodamage as sunburn cell formation, DNA fragmentation and lipid peroxidation, which were caused by a single dose of UVB irradiation. These results suggest that the protective effect of 20 mM As-2P on UVB-induced cutaneous damage is due to the maintenance of a normal As level by conversion of As-2P to As in skin tissue.

Application of curdlan to controlled drug delivery. II. In vitro and in vivo drug release studies of theophylline-containing curdlan tablets

Tablets (300 mg) having two different surface areas were prepared from spray-dried particles of curdlan (100 mg)/theophylline(200 mg). Drug release from the tablets was studied in vitro and in vivo. The in vitro drug release from a tablet with a larger surface area (Tab L) was faster than that with a smaller one (Tab S). The water uptake of Tab L was larger than that of Tab S, probably due to the difference in the tablets' surface areas. However, the water uptake was not a rate-determining step for the drug release from curdlan tablets containing a large amount of theophylline. A straight line was obtained when release % was plotted vs. time. The slope of each curve was calculated as 0.59 for Tab L and 0.58 for Tab S. This indicates that the release mechanism is non-Fickian diffusion controlled. In addition, the curdlan tablets or theophylline powder were administered orally to 5 healthy volunteers, and saliva concentrations of theophylline were determined. Each saliva concentration was converted to plasma concentration using the saliva to plasma ratio of the drug in each subject. The AUC of Tab L was nearly the same as that of powder, while the AUC of Tab S was smaller than that of powder. The mean residence times (MRTs) of theophylline powder, Tab S and Tab L were 11.1 +/- 1.5, 25.4 +/- 6.3 and 17.1 +/- 1.5 h (N = 4-5, mean +/- S.D.), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Synergistic combinations of recombinant human tissue-type plasminogen activator and human single-chain urokinase-type plasminogen activator. Effect on thrombolysis and reocclusion in a canine coronary artery thrombosis model with high-grade stenosis

The synergistic effects of recombinant human tissue-type plasminogen activator (rt-PA) and single-chain urokinase-type plasminogen activator (scu-PA) on coronary arterial thrombolysis were investigated in open-chest dogs with thrombosis of the left anterior descending coronary artery and a superimposed high-grade stenosis. A 90% stenosis was generated by external constriction, reducing blood flow to 40 +/- 10% of baseline. Localized thrombosis was produced by endothelial cell injury and instillation of thrombin and fresh blood. Intravenous infusion for 60 minutes of either 30 micrograms/kg/min rt-PA alone or 10 micrograms/kg/min scu-PA alone consistently produced coronary artery recanalization (six of eight dogs and five of five dogs, respectively) but was almost always associated with reocclusion during or shortly after the end of the infusion (four of six dogs and five of five dogs, respectively). Infusion of either 15 micrograms/kg/min rt-PA or 5 micrograms/kg/min scu-PA for 60 minutes did not cause coronary artery recanalization (none of four dogs in each group). Combined infusion of 7.5 micrograms/kg/min rt-PA and 2.5 micrograms/kg/min scu-PA for 60 minutes (one fourth of the minimum thrombolytic dose of each agent) induced coronary artery recanalization (six of six dogs) but was also associated with early reocclusion (six of six dogs). Combined infusion of 3.75 micrograms/kg/min rt-PA and 1.25 micrograms/kg/min scu-PA for 60 minutes did not consistently cause recanalization (one of four dogs). Combined infusion of 15 micrograms/kg/min rt-PA and 5 micrograms/kg/min scu-PA for 60 minutes caused recanalization in all of six dogs but was associated with reocclusion in all six.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiotoxicity of trastuzumab (herceptin) in chick embryos

The cardiac toxicity of trastuzumab was studied in chick embryos. Fertilized eggs of White Leghorns were incubated and investigated. Trastuzumab 5 mg/egg (low dose) or 15 mg/egg (high dose) was injected into the air sac of a fertilized egg on the 16th day of incubation. Electrocardiograms (ECGs) were recorded 0 to 60 min after the injection. After low dosing of trastuzumab, the heart rate was not different compared with the control. However, the heart rate was significantly decreased by high dosing of trastuzumab. In addition, arrhythmia was produced by high dosing of trastuzumab. These findings indicate that trastuzumab has a marked dose- and time-dependent influence on the heart rate in chick embryos.

Experimental diabetes model in chick embryos treated with streptozotocin

The aim of the present study was to investigate whether diabetes model can be made by treatment of streptozotocin (STZ) in chick embryos and this model can be used to predict the effect of drug. When STZ (0.3 mg/egg) was injected into the albumen of fertile eggs on the 14th day of incubation, level of blood glucose significantly increased than that of the control on the 17th day of incubation, and level of serum insulin significantly decreased. In addition, the enhanced level of blood glucose in STZ-treated embryos reduced by injection of human insulin. In conclusion, STZ-treated embryos may be applicable to evaluate human insulin and anti-diabetes drugs as an experimental diabetes model.

Clinicopathological significance of expression of CD44 variants in head and neck squamous cell carcinoma

Splice variants of the cell surface glycoprotein CD44 have been reported to be associated with the progression of various human tumors. The aim of this study is to determine the correlation between the expression of CD44 isoforms, especially CD44 variant 2 (CD44v2), and the clinicopathological features of head and neck squamous cell carcinomas (HNSCCs). The expression of CD44 isoforms was evaluated immunohistochemically in paraffin-embedded tissues from 89 primary lesions, using monoclonal antibodies against CD44 standard (CD44st), CD44 variant 6 (CD44v6) and CD44v2. Cancer tissues from 89 (100%), 85 (95.5%) and 59 (66.3%) patients showed positive immunoreactivity for CD44st, CD44v6 and CD44v2, respectively. A significant correlation was observed between the down-regulation of CD44v2 and poorer differentiation of the tumor cells (P = 0.02). We could not find any significant correlation between the expression of CD44v2 and T stage or N stage (lymph node status). However, the rate of positive cervical lymph node metastasis tended to increase with reduced expression of CD44v2 (P = 0.08). Down-regulation of CD44v2 expression was correlated with shorter overall survival (P = 0.01). Furthermore, Cox's multivariate analysis revealed that only CD44v2 expression and lymph node status were independent prognostic factors. These findings suggest that down-regulation of CD44v2 expression may be one of the biological markers for the degree of malignancy in HNSCCs.

Protective effect of ceftriaxone against the nephrotoxicity of isepamicin administered once daily in rats

The protective effect of ceftriaxone on isepamicin-induced nephrotoxicity was investigated. For 14 d, Wistar rats were administered either ceftriaxone 100 mg/kg intraperitoneally, isepamicin 300 mg/kg subcutaneously, or ceftriaxone isepamicin in combination. The animals given 300 mg/kg of isepamicin showed a significant increase in urine NAG (N-acetyl-beta-D-glucosaminidase) levels as compared with the control animals which received saline (p<0.01). However, the increase in NAG level was markedly less when isepamicin was administered in combination with ceftriaxone (p<0.01). Ceftriaxone alone had no effect on urine NAG activity. Serum creatinine levels were significantly higher in animals treated with isepamicin alone than in control animals (p<0.01) or animals receiving the isepamicin ceftriaxone combination (p<0.01). After 14 d of treatment, ceftriaxone had not accumulated in renal tissue, but it did reduce the renal intracortical accumulation of isepamicin (p<0.01). Histopathologically, ceftriaxone induced very few cellular alterations and considerably reduced the manifestation of typical signs of isepamicin nephrotoxicity. This investigation demonstrates that ceftriaxone protects animals against isepamicin-induced nephrotoxicity.

Protective effect of fleroxacin against the nephrotoxicity of isepamicin in rats

The protective effect of fleroxacin on isepamicin-induced nephrotoxicity was investigated. Wistar rats were administered either fleroxacin 100 mg/kg orally, isepamicin 300 mg/kg subcutaneously, or fleroxacin and isepamicin in combination for 14 d. The animals given 300 mg/kg of isepamicin showed a significant increase in urine N-acetyl-beta-D-glucosaminidase (NAG) levels as compared with the control animals which received saline (p<0.01). However, the increase in NAG level was markedly less when isepamicin was administered in combination with fleroxacin (p<0.01). Fleroxacin alone had no effect on urine NAG activity. Serum creatinine and blood urea nitrogen (BUN) levels were significantly higher in animals treated with isepamicin alone than in the control animals (p<0.01) or animals receiving the isepamicin fleroxacin combination (p<0.01). Histopathologically, fleroxacin induced very few cellular alterations, but considerably reduced the manifestation of typical signs of isepamicin nephrotoxicity. This investigation demonstrates that fleroxacin protects animals against isepamicin-induced nephrotoxicity.

Manifest Anxiety Scale for evaluation of effects of granisetron in chemotherapy with CDDP and 5FU for head and neck cancer

The level of anxiety was examined before treatment by means of the Manifest Anxiety Scale (MAS) in 41 patients with squamous cell carcinoma of the head and neck. They received 5 days of neoadjuvant chemotherapy with cisplatin (CDDP) and 5-fluorouracil (5FU). Granisetron (KYT) was administered daily from day 1 to day 5. Nausea, vomiting, appetite, and well-being were assessed during and after chemotherapy. The relation between the effects of KYT and anxiety was studied. Seventeen patients were proven to have anxiety and were compared with the other 24 patients. In patients with anxiety, the percentage well-being was significantly lower on days 1 and 2 (P=0.008, 0.001). The rate of freedom from nausea was significantly lower from day 4 to day 9 for anxiety patients (P=0.010-0.050). The percentage of anxiety patients without loss of appetite was significantly lower from day 6 to 9 (p=0.001-0.020). The rate of freedom from vomiting was significantly lower on days 4, 5 and 7 for anxiety patients (P=0.024, 0.024, 0.014). The results indicate that the effect of KYT was significantly lower from day 3 to day 7 for anxiety patients (P=0.008-0.045). The anxiety group had significantly poorer well-being at the beginning of chemotherapy, and were not responsive to KYT in the delayed phase. Our results prove that anxiety patients show delayed emesis, and the administration of KYT is considered insufficient. It may be important to co-administer a tranquilizer to any patient who exhibit anxiety as defined by the MAS, in order to reduce delayed emesis.