Uptake by hepatocytes and biliary excretion of intravenously administered polystyrene microspheres in rats

The in vivo uptake by hepatocytes and biliary excretion of fluorescein isothiocyanate-labeled polystyrene microsphere with a particle size of 50 nm (MS-50) after intravenous administration was studied in rats. It was confirmed by using confocal laser scanning microscopy that MS-50 was partially phagocytosed by the hepatocytes and that MS-50 taken up by the hepatocytes existed exclusively inside the cells 1 h after intravenous administration. Studies on the mechanism of the uptake of MS-50 by the hepatocytes using the liver perfusion technique revealed that a process mediated by apo-E was involved. After intravenous administration of MS-50, about 4% of dose was excreted into bile in 24 h. Pharmacokinetic evaluation of the excretion rate of MS-50 into bile showed that the process followed first-order kinetics. Qualitative evaluation of the fluorescence detected in the bile after intravenous administration of MS-50 revealed that the particles were certainly excreted into bile in an intact form. From these results, it was suggested that intravenously administered MS-50 would be partially phagocytosed by hepatocytes through a process mediated by apo-E and that MS-50 ingested by hepatocytes would be partially excreted into the bile.

Flower-predominant expression of a gene encoding a novel class I chitinase in rice (Oryza sativa L.)

A flower-predominant cDNA for a gene, termed OsChia 1;175, was isolated from a cDNA library of rice pistils. Northern blot and RT-PCR analyses revealed that the OsChia 1;175 gene is highly expressed in floral organs (pistils, stamens and lodicules at the heading stage) but not or at an extremely low level in vegetative organs. OsChia 1;175 encodes a protein that consists of 340 amino acid residues, and the putative mature protein shows 52% to 63% amino acid identity to class I chitinases of rice or other plants. The phylogenetic tree shows that the OsChia 1;175 protein is a new type of plant class I chitinase in rice. The expression of OsChia 1;175 in vegetative organs is not induced by several chemicals, UV, and wounding. The soluble putative mature OsChia 1;175 protein expressed in Escherichia coli exhibited chitinase activity in the assay with colloidal chitin as a substrate. Genomic Southern analysis revealed that the OsChia 1;175 gene was organized as a low-copy gene family. The rice genomic library was screened and a genome clone corresponding to OsChia 1;175 was isolated. The transcription start sites of the OsChia 1;175 gene were mapped by primer extension analysis. The 1.2 kb putative promoter region of the OsChia 1;175 gene was fused to the GUS (beta-glucuronidase) gene, and this chimeric gene was introduced to rice by Agrobacterium-mediated transformation. The flower-predominant gene expression was identified also in the transgenic rice plants. The high promoter activity was detected in the stigmas, styles, stamens and lodicules in transgenic plants. The possible functions of OsChia 1;175 are discussed.

Intratumoral pharmacokinetics of oligonucleotides in a tissue-isolated tumor perfusion system

The intratumoral pharmacokinetics of model oligonucleotides were studied in Walker 256 tissue-isolated tumor preparations using an in situ single-pass vascular perfusion technique. A 20-mer phosphodiester (PO) oligonucleotide, its fully phosphorothioated (PS) oligonucleotide counterpart, and an 18-mer phosphorothioated oligonucleotide containing four 2'-O-methylribonucleosides at both the 3'-end and 5'-end (PS-OMe) were used. These oligonucleotides were administered to the tumor in two ways, by constant arterial infusion and by direct intratumoral injection. In the case of constant arterial infusion, the experiments were carried out using perfusate with or without 4.7% bovine serum albumin (BSA). The protein binding of PO, PS, and PS-OMe to BSA was 46%, 87%, and 94%, respectively. No marked difference was observed between the degree of accumulation of the three types of oligonucleotides in the tumor when BSA was present in the perfusate. PS and PS-OMe showed higher degrees of accumulation in tumors compared with PO when no BSA was present. These results indicate that free (i.e., protein unbound) PS-OMe and PS have superior tumor accumulation characteristics. In the intratumoral injection experiments, PS-OMe was retained longer in tumor tissue compared with PS, suggesting that it might be useful for direct local injection into solid tumors. Thus, the present study provides useful information about the basic disposition characteristics of oligonucleotides in solid tumors.

Integral method to study transition radiation from surfaces with arbitrary profile

Transition radiation is produced when an electron moving at constant speed crosses the boundary separating two media with different optical properties. We propose an alternative description of this phenomenon, based on an integral representation of the electromagnetic field and show that the approach gives known results for a flat surface. Compared to previously published methods, based either on the reciprocity theorem in electromagnetism or on a four-dimensional Fourier representation of the field generated by the moving electron, this method has the advantage that it can be applied to general boundary geometries.

Age-dependent decreases of phosphorus and magnesium in human Achilles' tendons

To elucidate changes of human tendons with aging, the authors studied age-related changes of elements in human Achilles' tendons by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of seven men and seven women, ranging in age from 61 to 97 yr. It was found that the content of calcium increased progressively with aging in the Achilles' tendons, whereas the contents of phosphorus and magnesium decreased gradually with aging. The previous investigations demonstrated that the content of calcium and phosphorus increased progressively with aging in most, but not all, human tissues, except for the bones. In ligaments, such as the anterior cruciate ligament and the ligament of the head of the femur, which are histologically similar to the Achilles' tendon, it was previously found that both the contents of calcium and phosphorus increased with aging in the ligaments. It should be noted that the content of phosphorus in the Achilles' tendons decreased during the aging process. In addition, it was found that there was a very high direct correlation between phosphorus and magnesium contents in the tendons, but not between calcium and phosphorus contents.

Hepatocyte-targeted in vivo gene expression by intravenous injection of plasmid DNA complexed with synthetic multi-functional gene delivery system

To achieve hepatocyte-targeted in vivo gene expression, a carrier that controls both the tissue and intracellular distribution of DNA was designed and synthesized. A cationic polymer, poly(L-ornithine) (pOrn), was modified first with galactose, then with a fusigenic peptide (mHA2) to obtain Gal-pOrn-mHA2. When applied with Gal-pOrn-mHA2 to asialoglycoprotein receptor-positive cells, fluorescein-labeled DNA showed a diffuse profile, suggesting the release of DNA from endosomes and/or lysosomes by the carrier. Then the biodistribution and gene expression after intravenous injection of DNA complexes (10 microg DNA per mouse) were examined. After injection of [32P]DNA/Gal-pOrn-mHA2, about 60% of the radioactivity was recovered in the liver, mostly in parenchymal cells. A large amount (81 ng/g tissue) of transgene product (luciferase) was detected in the liver of mice injected with DNA/Gal-pOm-mHA2, which was 280-fold greater than that obtained with DNA/DOTMA:Chol liposomes (50 microg DNA). Prior administration of galactosylated albumin reduced the gene expression to 1/100, indicating the asialoglycoprotein receptor-mediated gene transfer in liver parenchymal cells, ie hepatocytes. The luciferase activity in hepatocytes contributed more than 95% of the total activity in all the tissues examined. Thus, hepatocyte-targeted in vivo gene expression was achieved by the intravenous injection of DNA complex with the multifunctional gene carrier.

Design of polymeric prodrugs of PGE1 for cell-specific hepatic targeting

Based on the relationship between in vivo disposition of macromolecules and their physicochemical and biological characteristics obtained through clearance concept-based pharmacokinetic analysis, polymeric prodrugs of prostaglandin E1 (PGE1) were designed stepwise and evaluated on their targeting and therapeutic efficiencies. Although galactosylated poly-L-glutamic acid with a ethylene diamine (ED) spacer (Gal-ED-PLGA) showed good targeting efficacy in mice, its PGE1 conjugate synthesized by the carbonyldiimidazole method failed to show therapeutic effects probably due to inactivation of PGE1 during conjugation and lack of release in the tissue. In order to overcome these problems, PGE1 was conjugated to galactosylated poly-(L-glutamic acid) hydrazide (Gal-HZ-PLGA) via hydrazone bond. The PGE1-Gal-HZ-PLGA conjugate labeled with [111In] or [3H]PGE1 rapidly accumulated in the liver parenchymal cells after intravenous injection. In addition, PGE1 conjugate effectively inhibited the increase of GPT level in plasma, while free PGE1 indicated no therapeutic efficacy even at more than ten times higher doses, in carbon tetrachloride-induced hepatitis mice. These findings suggest potentials of polymeric targeting systems of PGE1 to hepatocyte utilizing galactose recognition.

Follow-up study of MRI for osteochondral lesion of the talus

Characteristic MRI findings of osteochondral lesions of the talus have been reported. We examined how they change before and after treatment and discussed their significance. Twenty two ankles in 21 patients had MRI examination before and after treatment of the talar lesion. We evaluated the changes in the low intensity areas in T1-weighted image and the signal rims behind osteochondral fragment in T2-weighted image which have been reported as characteristic findings. Clinical symptoms were improved postoperatively in all subjects. The low intensity areas in T1-weighted image seen before the surgical treatment tended to decrease in size postoperatively. The low intensity area in T1-weighted image was reduced in 15 of the 22 ankles (68.2%). Low signal rim in T2-weighted image was seen in three cases before the treatment. All disappeared completely after arthroscopic drilling. Similarly, high signal rim in T2-weighted image seen in 13 cases before the treatment disappeared in 10 postoperatively. These findings were considered indicative that surgical treatments reduced abnormal stress of the underlying bone element due to unstable osteochondral fragment, leading to reduction of the low intensity area. The disappearance of signal rims in T2-weighted images was considered to indicate obliteration of the interface between the osteochondral fragment and the talar bed with bone union. We believe that MRI of the osteochondral lesion of the talus will be useful for postoperative evaluation allowing assessment of the need for further treatment. The decreasing size of low intensity areas in T1-weighted images and disappearance of signal rims behind the osteochondral fragment in T2-weighted images suggested healing of the osteochondral lesions.

Treatment of extrinsic flexion deformity of the toes associated with previous removal of a vascularized fibular graft

BACKGROUND

Complications from vascularized fibular bone-grafting are infrequent. We saw six patients who had a painful flexion deformity of the great and lesser toes after a free vascularized fibular graft had been obtained from the ipsilateral leg. In this report, we discuss our management of these patients.

METHODS

Painful flexion deformity of the toes that had developed in six adults after removal of a free vascularized fibular graft was treated by cutting of the flexor hallucis longus alone in three patients, by lengthening of the flexor hallucis longus alone in one, and by cutting of both the flexor hallucis longus and the flexor digitorum longus in two.

RESULTS

After an average duration of follow-up of six years and eleven months, the flexion deformity of the great and lesser toes had decreased or disappeared, leading to improved or full extension of the digits. Preoperative and postoperative measurements of muscle strength for plantar flexion of the interphalangeal joints did not change appreciably.

CONCLUSIONS

Cutting or lengthening of the flexor hallucis longus behind the ankle provides an adequate release of digital flexion deformities that occur after removal of a vascularized fibular bone graft.

Design of polymeric prodrugs of prostaglandin E(1) having galactose residue for hepatocyte targeting

Based on the relationship between in vivo disposition of macromolecules and their physicochemical and biological characteristics obtained through clearance concept-based pharmacokinetic analysis, polymeric prodrugs of prostaglandin E(1)(PGE(1)) were designed stepwise and evaluated on their targeting and therapeutic efficiencies. First poly-L-lysine (PLL) and poly-L-glutamic acid (PLGA) with an ethylenediamine (ED) spacer were modified with 2-imino-2-methoxyethyl 1-thiogalactoside to obtain galactosylated derivatives. After intravenous injection in mice, Gal-ED-PLGA was selectively taken up by the liver parenchymal cells via receptor-mediated endocytosis, while Gal-PLL accumulated in the liver as well as PLL mostly due to electrostatic interaction. Although Gal-ED-PLGA showed good targeting efficacy, its PGE(1) conjugate synthesized with activated PGE(1) by carbonyldiimidazole method failed to show therapeutic effects probably due to inactivation of PGE(1) during conjugation and lack of release in the tissue. In order to overcome these problems, we next conjugated PGE(1) to galactosylated poly-(L-glutamic acid) hydrazide (Gal-HZ-PLGA) in which PGE(1) was easily coupled to Gal-HZ-PLGA via a hydrazone bond in weak acidic solution (pH 5) at room temperature. The PGE(1)-Gal-HZ-PLGA conjugate labeled with [(111)In] or [(3)H]PGE(1) rapidly accumulated in the liver parenchymal cells. In addition, the PGE(1) conjugate effectively inhibited the increase of the GPT level in plasma, while free PGE(1) indicated no therapeutic efficacy even at more than ten times higher doses, in carbon tetrachloride-induced hepatitis mice. These findings suggest potentials of polymeric targeting systems of PGE(1) to hepatocyte utilizing galactose recognition.

Development of the ball-and-socket ankle as assessed by radiography and arthrography. A long-term follow-up report

We studied the development of ball-and-socket deformity of the ankle by arthrography and radiography in 14 ankles of ten patients with congenital longitudinal deficiency of the fibula accompanied by various anomalies. The mean follow-up was for 18 years 10 months. In three ankles in infants less than one year old the lateral and medial sides of the ankle were already slightly round. In another seven ankles the ball-and-socket appearance developed before the age of five years. This was thought to be due to osseous coalition which limits eversion and inversion. In another four ankles in children who were over the age of one year at the initial examination, the deformity was demonstrated by arthrography and radiography at their first examination. Ball-and-socket deformity accompanied by tarsal coalition is an acquired deformity secondary to limitation of movement of the subtalar and midtarsal joints. It has completely developed by about five years of age.

Interaction of polystyrene microspheres with liver cells: roles of membrane receptors and serum proteins

Our previous studies have demonstrated that serum would play an important role in the hepatic disposition of polystyrene microspheres (MS) and that complement C3 should be involved as the serum opsonin. In this study, we tried to identify the entity of other serum opsonins and dysopsonin for the hepatic uptake of MSs with particle sizes of 50 nm (MS-50) and 500 nm (MS-500) by isolated liver perfusion studies using a recirculation procedure in rats. Pretreatment of the liver by trypsin significantly suppressed the serum-dependent hepatic uptake of both MSs, suggesting that some protein components on the cell surface should be necessary for the serum-dependent phagocytosis of MSs. Pretreatment of the serum by the anti-fibronectin antibody resulted in a significant reduction in the hepatic disposition of MS-500 (49% of control), suggesting that fibronectin should also work as the opsonin for the hepatic uptake of MS-500. The hepatic disposition of both MSs in the presence of serum was inhibited by the addition of N-acetylgalactosamine into the perfusate, suggesting the possible involvement of lectin in the serum-dependent hepatic uptake of MSs. Furthermore, a more intensive hepatic disposition of MSs was observed in the presence of plasma compared with that in the presence of serum in the perfusate, suggesting the possible involvement of blood coagulation factors, such as fibrinogen, as the opsonin in the hepatic disposition of MSs.

Hindfoot alignment of hallux valgus evaluated by a weightbearing subtalar x-ray view

A new radiographic view was proposed to evaluate alignment of the hindfoot under weightbearing condition. The ankle joint and the middle and posterior facets of the subtalar joint were clearly visualized in all radiographs. A comparative study was made of 104 feet with hallux valgus in 58 female patients and 67 normal feet in 57 normal female subjects (control group). The mean value of the angle between the axis of the tibia and a line on the surface of the ankle joint on the talus was significantly larger in the group with hallux valgus than in the control group. Likewise, the mean value of the angle between the axis of the tibia and a line on the surface of the posterior facet of the subtalar joint on the calcaneus in the group with hallux valgus was 95.3 degrees, significantly larger than the 87.9 degrees in the control group. These findings showed that the ankle joint and the posterior facet of the subtalar joint in hallux valgus have valgus deviation. The hindfoot in a foot with hallux valgus has a tendency toward pronation. No previous study has measured the inclination of the posterior facet of the subtalar joint directly in weightbearing.

Mechanisms of hepatic disposition of polystyrene microspheres in rats: effects of serum depend on the sizes of microspheres

To study the mechanisms of the hepatic disposition of polystyrene microspheres (MS), effects of serum on their hepatic disposition characteristics were investigated for MSs with particle sizes of 50 nm (MS-50) and 500 nm (MS-500) by isolated liver perfusion experiments. It was revealed that serum in the perfusate inhibited and promoted the hepatic disposition of MS-50 and MS-500 at 37 degrees C, respectively. However, pre-heating at 56 degrees C or pre-treatment with anti-C3 antibody of serum reduced the promotive effect of serum on the hepatic uptake of MS-500, suggesting that the complement system should be involved as opsonins for the hepatic uptake of MS-500. Hepatic disposition of both MSs at 4 degrees C was reduced by the addition of serum into the perfusate, which could be ascribed to the reduction of the surface hydrophobicity of MSs due to the adsorption of serum proteins onto the surface of MSs and to resultant decrease in non-specific disposition to the liver. From these results, serum was found to function both as the opsonin to enhance the hepatic uptake of MSs and as the inhibitor by reducing non-specific interaction between MSs and the plasma membrane. Whether serum promotes or inhibits the hepatic disposition of MSs would be dependent on the particle sizes of MSs.

Development of a hepatocyte-specific prostaglandin E(1) polymeric prodrug and its potential for preventing carbon tetrachloride-induced fulminant hepatitis in mice

A polymeric prodrug of prostaglandin E(1) (PGE(1)) was synthesized using galactosylated poly(L-glutamic acid hydrazide) (Gal-HZ-PLGA) as a biodegradable and targetable carrier to hepatocytes. Poly(L-glutamic acid hydrazide) was prepared by reacting poly(gamma-benzyl-L-glutamate) with hydrazine monohydrate, followed by reaction with 2-imino-2-methoxyethyl-1-thiogalactosides to obtain Gal-HZ-PLGA after i.v. injection. (111)In-labeled galactosylated poly(L-glutamic acid hydrazide) ((111)In-Gal-HZ-PLGA) rapidly accumulated in the liver in a dose-dependent manner, whereas (111)In-poly(L-glutamic acid hydrazide) did not, indicating the involvement of a galactose-specific mechanism in the uptake of (111)In-Gal-HZ-PLGA. Fractionation of liver cells revealed that (111)In-Gal-HZ-PLGA was preferentially taken up by liver parenchymal cells. After being taken up by the liver, (111)In-Gal-HZ-PLGA was gradually degraded, and radioactive metabolites with low molecular weight were detected within 10 min after injection. Then, PGE(1) or [(3)H]PGE(1) was coupled to Gal-HZ-PLGA via a hydrazone bond under mild conditions to obtain PGE(1) conjugate. After i.v. injection, [(3)H]PGE(1) conjugate was rapidly taken up by the liver (more than 80% of the dose). After injection of the conjugate, (3)H radioactivity remained in the liver, representing about 70% of the dose, even at 24 h, whereas little radioactivity remained in the organ at 1 h after the injection of free [(3)H]PGE(1). Finally, its pharmacological activity was examined in mice with fulminant hepatitis induced by peritoneal injection of carbon tetrachloride. The i.v. injection of PGE(1) conjugate at a dose of 1 mg (0.074 mg PGE(1))/kg effectively inhibited the increase of plasma glutamic pyruvic transaminase activity, whereas twice this dose (0.15 mg/kg) of free PGE(1) had little effect. These results suggest that the PGE(1) conjugate is an excellent polymeric prodrug of PGE(1) for hepatitis therapy.

Arthroscopic drilling for the treatment of osteochondral lesions of the talus

BACKGROUND

An osteochondral lesion of the talus is a relatively rare disorder of the ankle. While a number of treatment options have been reported, it appears to be difficult to manage all lesions with a single approach. We evaluated the indications for and the results of arthroscopic drilling for the treatment of an osteochondral lesion of the talus.

METHODS

Eighteen ankles (seventeen patients) with a symptomatic osteochondral lesion of the talus were examined. The ages of the patients ranged from ten to seventy-eight years (mean, 28.0 years) at the time of the operation, and the patients were followed postoperatively for two to 9.5 years (mean, 4.6 years). After the continuity of the cartilage overlying the lesion and the stability of the lesion had been confirmed, arthroscopic drilling was performed with use of a Kirschner wire that was 1.0 to 1.2 millimeters in diameter. A cast was not applied postoperatively, and full weight-bearing was allowed six weeks after the procedure.

RESULTS

The clinical result was good for thirteen ankles and fair for five; all ankles had improvement. Twelve of the thirteen ankles that were in patients who were less than thirty years old had a good result. In contrast, only one of the five ankles in patients who were fifty years old or more had a good result. Thus, the clinical results tended to be better for younger patients. Improvement was seen radiographically in fifteen ankles. However, the three ankles in patients who were more than sixty years old were found to have no improvement on radiographic examination. Analysis of the group of patients who had a history of trauma revealed that the mean interval between the injury and the operation was 6.3 months for the three ankles that had a good radiographic result and 11.3 months for the six that had a fair result. Thus, the radiographic results tended to be better when the interval between the injury and the operation was shorter.

CONCLUSIONS

Arthroscopic drilling for the treatment of medial osteochondral lesions of the talus does not require osteotomy of the medial malleolus or postoperative immobilization; thus, the procedure is less invasive than other types of operative treatment for the condition and it allows early resumption of daily activities and sports. On the basis of the results in this study, we believe that the procedure is effective and useful in young patients, especially those who have not yet had closure of the epiphyseal plate. A specific indication for the procedure is an early lesion with only mild osteosclerosis of the surrounding talar bone, continuity of the cartilaginous surface, and stability of the osteochondral fragment.

Neurohistology of the sinus tarsi and sinus tarsi syndrome

The purpose of this study was to clarify the neural anatomy of the sinus tarsi. The nerve endings of the synovium in the sinus tarsi were examined. The synovial membrane in the sinus tarsi was excised in 20 patients with sinus tarsi syndrome (20 feet) and in 2 feet from subjects without symptoms (controls). In 15 of the 20 patients and the two controls, the excised synovial membrane was studied histologically with staining by a modified Gairns gold chloride method. Numerous neural elements were observed in the sinus tarsi in all examined synovium. There were abundant free nerve endings and three types of mechanoreceptors: Pacinian corpuscles, Golgi corpuscles, and Ruffini corpuscles. Macroscopic observation and histological examination, using hematoxylin and eosin, in the other 5 patients revealed chronic synovitis in the sinus tarsi. Our findings suggest that the sinus tarsi is not only a talocalcaneal joint space but a source of nociceptive and proprioceptive information on the movement of the foot and ankle. Sinus tarsi syndrome may result from disorders of nociception and proprioception in the foot.

Disposition of radioactivity after injection of liver-targeted proteins labeled with 111In or 125I. Effect of labeling on distribution and excretion of radioactivity in rats

The effect of radiolabeling liver-specific proteins on the in vivo disposition of radioactivity was investigated. The suitability of 111In and 125I as radiolabels for protein disposition studies in vivo was examined. Galactosylated and cationized bovine serum albumin were labeled with either 125I by the chloramine-T method or 111In, using 1-(4-isothiocyanatobenzyl)ethylenediaminetetraacetic acid (SCN-BZ-EDTA) or diethylenetriaminepentaacetic acid (DTPA) as bifunctional chelating agents (BCAs) and administered intravenously to rats. 125I radioactivity disappeared rapidly from the liver with subsequent excretion in the urine and bile, mainly in the TCA soluble fraction. 111In-associated radioactivity, on the other hand, remained in the hepatic tissue in considerably higher amounts during the experiment and was excreted in the bile and urine to a lower extent when compared with 125I. When the effect of BCA on excretion of 111In radioactivity was compared, no significant differences were observed in the urinary clearances. However, biliary excretion was significantly higher for 111In-SCN-BZ-EDTA-bound radioactivity. In conclusion, when compared with 125I, 111In labeling seems to more accurately characterize the in vivo distribution of liver-targeted proteins after their iv administration in rats and allows a more accurate pharmacokinetic evaluation to be performed.

Pharmacokinetic evaluation of mannosylated bovine serum albumin as a liver cell-specific carrier: quantitative comparison with other hepatotropic ligands

To assess the feasibility of mannosylated macromolecules as a liver-specific carrier system, hepatic uptake characteristics of mannosylated bovine serum albumin (Man-BSA) were pharmacokinetically investigated. After intravenous injection, 111In-Man18-BSA accumulated in the liver up to 70% of dose at 2h; the endothelial cells and Kupffer cells contributed about 66% and 21% of the uptake, respectively. In single-pass perfusion experiments using rat liver at varying inflow concentrations (0.1-2.0 microg/ml), 111In-Man18-BSA and 111In-Man33-BSA were continuously extracted by the liver and their extraction ratios decreased with the increasing inflow concentrations. The outflow curves of each 111In-Man-BSA at three concentrations were simultaneously fitted to a pharmacokinetic model including a binding to the cell surface and an internalization, by using a nonlinear regression program MULTI(RUNGE). The binding constant augmented with the increase in the number of mannose per BSA, whereas the internalization rate constant was quite comparable for both derivatives. The pharmacokinetic analysis has demonstrated that the uptake process of 111In-Man-BSA is characterized to possess fewer binding sites and a greater internalization rate in comparison with other liver-specific carriers such as galactosylated, succinylated and cationized BSAs. These results will provide useful information in designing drug targeting systems to the liver nonparenchymal cells via mannose receptors.

Targeted delivery and improved therapeutic potential of catalase by chemical modification: combination with superoxide dismutase derivatives

Four types of bovine liver catalase (CAT) derivatives, succinylated (Suc-CAT), galactosylated (Gal-CAT), mannosylated (Man-CAT), and polyethylene glycol conjugate (PEG-CAT), were synthesized and their pharmacokinetics and therapeutic potential in a hepatic ischemia/reperfusion injury model were studied in mice. About 90% of the CAT enzymatic activity was retained after chemical modification. Biodistribution studies showed that 111indium (111In)-Gal-CAT accumulated selectively in the liver parenchymal cells as 111In-CAT, whereas an increased amount of 111In-Suc-CAT and 111In-Man-CAT was delivered to liver nonparenchymal cells. 111In-PEG-CAT exhibited prolonged retention in plasma. Pharmacokinetic analysis revealed that the hepatic uptake clearances of 111In-Suc-CAT, 111In-Gal-CAT, and 111In-Man-CAT were much greater than that of 111In-CAT, whereas that of 111In-PEG-CAT was very small. In the ischemia/reperfusion injury model, in which hepatic injury was induced by occlusion of the portal vein for 30 min followed by 1 h reperfusion, the elevation of plasma glutamic pyruvic transaminase and glutamic oxaloacetic transaminase levels was slightly inhibited by treatment with native CAT or Gal-CAT. PEG-CAT was less potent. In contrast, Suc-CAT and Man-CAT effectively suppressed the increase in plasma glutamic pyruvic transaminase and glutamic oxaloacetic transaminase. Coinjection of mannosylated superoxide dismutase marginally improved the inhibitory effects of CAT derivatives. These results demonstrate that targeted CAT delivery to liver nonparenchymal cells via chemical modification is a promising approach to prevent hepatic injuries caused by reactive oxygen species. The potential usefulness of combining of CAT and superoxide dismutase derivatives is also demonstrated.

Age-related changes of elements in human anterior cruciate ligaments and ligamenta capitum femorum

To elucidate compositional changes of human ligaments by aging, the content of elements in anterior cruciate ligaments (ACLs) and ligamenta capitum femorum (LCFs) was analyzed by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of 11 men and 7 women, ranging from 59 to 91 yr of age. With regard to the content of elements, the content of sulfur and iron was significantly higher in the LCFs than in the ACLs. It was found in the ACLs that the content of sulfur decreased gradually with aging, whereas the content of calcium, phosphorus, and magnesium increased progressively with aging. On the other hand, it was found in the LCFs that the content of magnesium decreased gradually with aging, where as the content of phosphorus increased progressively with aging. The common finding that the content of phosphorus increased with aging, but the content of iron decreased, was obtained in the ACL and LCF. Regarding sexual difference, it was found in both the ACLs and LCFs that the content of phosphorus was higher in women's ligaments than in men's.

Hepatic uptake of polystyrene microspheres in rats: effect of particle size on intrahepatic distribution

The in vivo disposition of polystyrene microsphere (MS) with the particle size of 50 nm (MS-50) or 500 nm (MS-500) was characterized after intravenous administration to rats. A rapid elimination from systemic circulation was observed for both MSs. Tissue distribution of MS-50 and MS-500 at 1 h after intravenous injection indicated that both MSs were exclusively distributed to liver and that small but significant amounts of MS-50 and MS-500 were also distributed to lung and spleen, respectively. To investigate the intrahepatic distribution of MS, liver was separated into liver parenchymal cells (PC) and non-parenchymal cells (NPC) at 1 or 6 h after intravenous administration. The contribution of each cell fraction was dependent on both the size of MS and the time after administration. Furthermore, by separating the NPC into endothelial cells and Kupffer cells using a centrifugal elutriation method, their contribution was also evaluated. For both MSs, Kupffer cells were recognized to be mostly responsible for the hepatic uptake, although a significant amount of MS-50 (about 28% of total uptake) was taken up by PC. On the other hand, there was little contribution of PC (about 5%) to the hepatic uptake of MS-500. The endothelial cells were contributed larger to the uptake of MS-500 (about 24%) than that of MS-50 (13%).

Liver uptake and hepato-biliary transfer of galactosylated proteins in rats are determined by the extent of galactosylation

The effect of molecular mass and surface density of galactose residues on hepatic uptake and subsequent biliary excretion of galactosylated proteins was investigated in rats. Several proteins with different molecular weights (15-70 kDa) and different numbers of galactose units were synthesized and radiolabeled with 111In. Galactosylated proteins were administered i.v. to anaesthetized rats and samples of plasma and bile were collected for 3 h. Liver was harvested at the end of the experiments and the radioactivity of all samples was measured. Galactosylated proteins accumulated primarily in the liver and 2-10% of the administered dose appeared in the bile, mainly in undegraded form. The hepatic uptake clearance (Cl liver) and biliary excretion rate constant (kbile) of galactosylated proteins were calculated. No direct effect of molecular weight was observed, however, on increasing the galactose density, Cl liver increased from about 4 to 400 ml/h whereas kbile gradually decreased from about 0.057 to 0.007 (h-1). In conclusion, both hepatic uptake and biliary excretion of galactosylated proteins were found to be affected by the extent of galactosylation.

Long-term results of arthrodesis for osteoarthritis of the ankle

A bone graft in the shape of a triangular prism was taken from the anterior surface of the tibia and used in the arthrodesis in 43 joints of 42 patients with primary and secondary osteoarthritis of the ankle. The modified anterior sliding inlay graft method was used. The average period of external immobilization was 5.8 weeks (range, 27-84 days), and followup ranged from 2 years 4 months to 14 years 11 months (average, 7 years 2 months). Nonunion was detected in three (7%) patients: one patient returned to work without additional treatment, and the other two patients underwent followup surgery within 7 months, and bony union was achieved. The final rate of nonunion was 2.3%. After the operation, excellent alleviation of pain was obtained. However, dorsiflexion of the foot decreased from the preoperative average value of 10.5 degrees to the postoperative value of 4.2 degrees, and plantar flexion also decreased from the preoperative value of 24.7 degrees to the postoperative value of 14 degrees. In addition, the range of motion of the subtalar and Chopart joints gradually improved with little effect on daily living activities. The most appropriate position of arthrodesis of the ankle appears to be in the neutral position between dorsal and plantar flexion. In addition, the varus and valgus angle of the hindfoot should be in a neutral or slightly valgus position. Degenerative arthritis developed and advanced in the subtalar joint in 32.5% of the patients, and these degenerative changes were exacerbated in many patients if such changes were present before surgery. Tibial stress fracture occurred in two (4.7%) patients as a complication that was specific to the current surgical method. Thus, the surgical procedure was modified to prevent the onset of tibial stress fracture.