Fixation of osteochondral lesions of the talus using cortical bone pegs

We have treated osteochondral lesions of the talus using cortical bone pegs. We examined 27 ankles (27 patients) after a mean follow-up of 7.0 years (2 to 18.8). The mean age of the patients was 27.8 years (12 to 62). An unstable osteochondral fragment or osteosclerotic changes in the bed of the talus were regarded as indications for the procedure. The clinical results were good in 24 ankles (89%) and fair in three (11%); none had a poor result. There was also radiological improvement in 24 ankles. Repair of the articular surface and stability of the lesion can be achieved even in unstable chronic lesions.

Viability of hypothermic preserved muscle determined by gene expression levels

We report a muscle viability index (MVI) that reflects mRNA degradation. The viability of hypothermically preserved (48C) rat skeletal muscle was evaluated using this MVI. To evaluate the hypothermic ischaemic insult of the muscle, 21 hind limbs of Fischer rats (three subgroups of seven limbs each) were hypothermically preserved for 1h, 3h and 6h, before harvesting the tibialis anterior muscle. To investigate reperfusion injury after hypothermic preservation, an additional 28 limbs were transplanted to recipient Fischer rats after hypothermic ischaemia for either 3h or 6h. The transplanted muscles were harvested on either day 3 or day 7 after transplantation. Seven fresh muscles were also harvested, and used as controls. In the 3h ischaemia group, the MVIs of both the hypothermic-ischaemia and the ischaemia-reperfusion subgroups were comparable to the controls. Likewise, there were no significant differences between the controls and the 6h hypothermic ischaemia and ischaemia-reperfusion subgroups. These results show that muscle viability is maintained with hypothermic preservation of up to 6h, and after reperfusion. Therefore, in clinical replantations the amputated extremity should be preserved under hypothermic conditions from the time of injury to the time of surgery.

Low-intensity pulsed ultrasound enhances early healing of medial collateral ligament injuries in rats

OBJECTIVE

To investigate the effect of low-intensity pulsed ultrasound exposure on the healing of injured medial collateral ligaments.

METHODS

Thirteen male Sprague Dawley rats were used in the study. After surgical transection of the bilateral medial collateral ligaments, the ligament of 1 knee received low-intensity pulsed ultrasound exposure (30 mW/cm2 for 20 minutes daily), whereas no ultrasound was applied to the contralateral knee (control side). Eight rats were killed at 12 days after surgery, and 5 rats were killed at 21 days. The bilateral knees of 5 rats were used for mechanical testing at each of the 2 periods, and 12-day specimens of the remaining 3 rats were prepared for the electron microscopic examination. The knees of 5 additional rats were used to obtain mechanical data of the normal uninjured medial collateral ligament.

RESULTS

On the 12th day, the low-intensity pulsed ultrasound-treated side exhibited significantly superior mechanical properties when compared with the control side in ultimate load, stiffness, and energy absorption (P < .05). However, the treatment did not afford any mechanical advantage when tested on the 21st day. The mean diameter of the fibril was significantly larger on the treatment side than on the control side (P < .05).

CONCLUSIONS

Low-intensity pulsed ultrasound exposure is effective for enhancing the early healing of medial collateral ligament injuries.

Subtalar arthrography in recurrent instability of the ankle

Subtalar arthrography was done in 37 feet of 35 patients in whom recurrent instability of the ankle was diagnosed. There were 16 male and 19 female patients, with a mean age of 29.1 years (range, 11-56 years). The mean interval between the injury and arthrography was 4 years 3 months (range, 6 months-22 years). Anteroposterior, lateral, and oblique radiographs were obtained for all patients. Any leakage during arthrography into the ankle, tendon sheaths, or sinus tarsi was recorded. An oblique view of the microrecess along the interosseous ligament and an anteroposterior view of the lateral recess just under the end of the fibula were examined. At surgery, 13 feet had combined injuries of the anterior talofibular and calcaneofibular ligaments, and 24 feet had isolated injury of the anterior talofibular ligament. The findings of the two groups were significantly different when examined for leakage into the ankle, leakage into the peroneal tendon sheath, and the presence of the lateral recess. Presence of contrast medium in at least two of these three positive arthrographic findings showed 92.3% sensitivity and 87.5% specificity in making the diagnosis of calcaneofibular ligament injury. Subtalar arthrography is valuable in making the diagnosis of calcaneofibular ligament injury in recurrent instability of the ankle.

Surface hydrophobicity of particles is not necessarily the most important determinant in their in vivo disposition after intravenous administration in rats

The in vivo disposition of polystyrene microsphere (MS) with the particle size of 50 nm (MS-50) and lecithin-coated MS-50 (LMS-50) after intravenous administration to rats was characterized. While a rapid elimination from the systemic circulation was observed for MS-50, much more prolonged circulating property was observed for LMS-50. In addition, this in vivo disposition property of LMS-50 was suggested to be ascribed to its lower affinity to the liver, which is the determining organ of the in vivo disposition of MS-50. The evaluation of surface hydrophobicity of MS-50 and LMS-50 in buffer solution revealed that the surface of MS-50 is more hydrophobic than that of LMS-50. However, LMS-50 was oppositely found to be more hydrophobic than that of MS-50 in rat serum. The profiles of serum proteins associated with MS-50 and LMS-50 were also examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The results showed that the amounts of some adsorbed proteins are greatly different between MS-50 and LMS-50. From these findings, it was suggested that the substantial difference in the in vivo disposition between MS-50 and LMS-50 would not be attributed to the difference in their surface hydrophobicity in the blood, but the difference in the type of serum proteins associated with them.

Distal cement mantle thickness with a triangular distal centralizer inserted into the stem tip in cemented total hip arthroplasty

Fifty-seven hips undergoing a primary cemented total hip arthroplasty with use of a triangular distal centralizer inserted into the stem tip were investigated, with a special focus on distal cement mantle thickness. The subjects were 43 women and 3 men. When evaluated on conventional anteroposterior and lateral radiographs, the relative incidence of thin cement mantles in zones 3 or 5 owing to the distal centralizer was 15.8% (9 hips). Unsatisfactory findings were that the distal centralizer and distal part of the stem shifted to the cortex in 7 hips and bent or failed at the inserted site in 2 hips. There is risk of generating a thin cement mantle with use of the triangular centralizer and its insertion into the stem tip.

Synthesis and pharmacological activity of a novel water-soluble hepatocyte-specific polymeric prodrug of prostaglandin E(1) using lactosylated poly(L-glutamic hydrazide) as a carrier

A novel polymeric prodrug of prostaglandin E(1) (PGE(1)) was synthesized using lactosylated poly(L-glutamic hydrazide) (Lac-NH-PLGA) as a targetable carrier to hepatocytes. Poly(L-glutamic hydrazide) (PLGA-HZ) was prepared by reacting poly(gamma-benzyl-L-glutamate) with hydrazine monohydrate, followed by coupling with lactose via a hydrazone linkage. Then the lactosylated PLGA-HZ was reduced by sodium cyanoborohydride (NaBH(3)CN) in order to make the linkage irreversible (Lac-NH-PLGA). Finally, PGE(1) was bound to hydrazide moieties remaining in Lac-NH-PLGA without any condensing agent under weakly acidic conditions (pH 5) where PGE(1) would be chemically most stable at room temperature (PGE(1) conjugate). The PGE(1) conjugate prepared was sufficiently water-soluble in spite of the hydrophobic nature of its backbone (-NH-CH-CO-) and PGE(1) itself. After intravenous injection in mice, the [111In]PGE(1) conjugate rapidly accumulated in the liver, whereas [111In]PLGA-HZ did not, suggesting the involvement of a galactose-specific mechanism in the uptake of the [111In]PGE(1) conjugate. Fractionation of liver cells revealed that the [111In]PGE(1) conjugate was preferentially taken up by liver parenchymal cells. The pharmacological activity was examined in mice with fulminant hepatitis induced by intraperitoneal injection of carbon tetrachloride. Intravenous injection of the PGE(1) conjugate at a dose of 1 mg (0.065 mg PGE(1))/kg effectively inhibited the increase in plasma glutamic pyruvic transaminase (GPT) activity compared with that of free PGE(1) at a dose of 0.065 or 0.65 mg/kg. These results suggest that the PGE(1) conjugate is an excellent prodrug for the treatment of fulminant hepatitis.

Cell-specific delivery of genes with glycosylated carriers

Cationic liposomes and polymers have been accepted as effective non-viral vectors for gene delivery with low immunogenicity unlike viral vectors. However, the lack of organ or cell specificity sometimes hampers their application and the development of a cell-specific targeting technology for them attracts great interest in gene therapy. In this review, the potential of cell-specific delivery of genes with glycosylated liposomes or polymers is discussed. Galactosylated liposomes and poly(amino acids) are selectively taken up by the asialoglycoprotein receptor-positive liver parenchymal cells in vitro and in vivo after intravenous injection. DNA-galactosylated cationic liposome complexes show higher DNA uptake and gene expression in the liver parenchymal cells in vitro than DNA complexes with bare cationic liposomes. In the in vitro gene transfer experiment, galactosylated liposome complexes are more efficient than DNA-galactosylated poly(amino acids) complexes but they have some difficulties in their biodistribution control. On the other hand, introduction of mannose residues to carriers resulted in specific delivery of genes to non-parenchymal liver cells. These results suggest advantages of these glycosylated carriers in cell-specific targeted delivery of genes.

[Beta 3-adrenergic receptor agonists--past, present and future]

beta 3-Adrenergic receptors (beta 3-AR) play an important role in the thermogenesis in brown adipose tissue and lipolysis in white adipose tissue. beta 3-AR agonists developed in the early stages produced marked weight reduction and an anti-diabetic effect in rats and mice, but did not in humans, because of the difference in the chemical structure of the beta 3-AR. In 1995, a naturally occurring variant (Trp64Arg) of the human beta 3-AR gene was shown to be correlated with obesity and insulin resistance in Pima Indians. Moreover, the fact that white adipocytes produce various hormones and cytokines that cause life-style-related disease was recently made clear. Because the reduction of the visceral fat is thought to be important to prevent these diseases, the expectations for the human beta 3-AR agonist having a novel anti-obesity effect are rising. Some interesting findings were recently reported with beta 3-AR agonists: the difference of the lipolysis was dependent on the existence of the Trp64Arg mutation and the up-regulation effect of the UCP1 and beta 3-ARs themselves in the adipose tissue and skeletal muscle. Therefore, we introduce informations (past, present and future) on beta 3-AR agonists in this paper.

Primary osteogenic sarcoma of a finger proximal phalanx: a case report and literature review

Osteogenic sarcoma of the small bones of the hand is rare with only 15 cases documented. We describe a 12-year-old boy with an osteogenic sarcoma of the proximal phalanx of the middle finger. Wide excision in the form of ray amputation with a wide surgical margin was performed after neoadjuvant chemotherapy consisting of combined high-dose methotrexate, doxorubicin, ifosfamide, and cisplatin. To restore maximum function the index ray was transferred to the base of the third metacarpal. Adjuvant chemotherapy was administered subsequently. At 28-month follow-up evaluation there was no evidence of local recurrence of disease or distant metastasis and both function and appearance were good.

Clinical application of the reversed pedicled venous flap containing perivenous areolar tissue and/or nerve in the hand

A reversed pedicled venous flap containing perivenous areolar tissue and/or nerve was used to cover traumatic skin defects of seven fingers in six patients. The series consisted of six men, ranging in age from 20 to 57 years (average: 39 years). The reconstructed sites were four dorsal skin defects and three volar skin defects of the finger. The flap was designed on the dorsum of the hand, in such a way as to place a vein at the centre of the flap and not to involve the dorsal metacarpal artery. The flap contained a dorsal vein, perivenous areolar tissue and fascia of the interosseous muscle. Cutaneous nerves were present in three of the seven flaps. The pedicle of the flap was dissected distally to the finger web space and the flap was transferred to the skin defect. The size of the flap ranged from 1.4x4.5 cm to 6.0x7.0 cm. The average length of the pedicle was 1.6 cm. Skin grafting was needed at the donor site in one case (flap size: 6.0x7.0 cm), but primary closure was possible in the remaining cases. Postoperatively, the largest flap showed superficial necrosis, although it survived. The remaining flaps survived completely. This suggests that in a large flap the skin should be attached to the pedicle to prevent congestion. The flap can be elevated without reference to the dorsal metacarpal artery at the ulnar side of the dorsum of the hand. The flap is an effective option to reconstruct skin defects of the finger, especially the little finger.

Evaluation of the longitudinal arch of the foot with hallux valgus using a newly developed two-dimensional coordinate system

The purposes of the present study were to establish a method for the evaluation of the longitudinal arch, using a two-dimensional coordinate system, and to clarify the main point of flattening of the foot in patients with hallux valgus. Measurements on a weight-bearing lateral radiograph of the foot were performed in 186 feet of 110 women with symptomatic hallux valgus and in 93 normal feet of 72 women. A two-dimensional coordinate system was used to perform the measurements. In this coordinate system, the line connecting the lowest point of the first metatarsal head and the lowest point (O) of the calcaneus is fixed as the x-axis, and the line that is perpendicular to the x-axis and intersects the x-axis at point O is fixed as the y-axis. The mean values of the y-coordinates at the points of the medial longitudinal arch of the foot in the patients with hallux valgus were significantly lower than those in the normal subjects (P < 0.001). The values were noticeably lower at points on the navicular. However, no change was observed in the posterior talus body. The new coordinate system indicated that the main points of flattening of the foot in patients with hallux valgus were the plantar flexion of the talus and the sinking of the navicular.

Effects of erythrocytes and serum proteins on lung accumulation of lipoplexes containing cholesterol or DOPE as a helper lipid in the single-pass rat lung perfusion system

Plasmid DNA-cationic liposome complexes (lipoplexes) accumulate in the lung to a great extent immediately after intravenous administration, and gene expression occurs predominantly in the lung. However, the detailed mechanisms underlying the lung accumulation of lipoplexes are not fully understood. In this study, we investigated the effect of blood components on the lung accumulation of lipoplexes using a single-pass rat lung perfusion system. Two types of lipoplexes, Chol-containing lipoplex ([(32)P]DNA-DOTMA/Chol liposome complex) and DOPE-containing lipoplex ([(32)P]DNA-DOTMA/DOPE liposome complex), pre-incubated with whole blood, serum, or erythrocytes, were injected into the perfused lung via an artery. Similarly to in vivo observations, extensive lung accumulation was observed for both types of lipoplexes after incubation with whole blood during a single passage. The (32)P-labeled lipoplexes pre-incubated with erythrocytes showed similar lung accumulation, whereas their lung accumulation after incubation with serum was significantly reduced, suggesting that erythrocytes would be more responsible blood components for extensive uptake by the perfused lung. However, there was a clear difference in the amounts of the accumulated erythrocytes after intra-arterial injection between the two lipoplex formulations. A significant degree of erythrocyte accumulation was observed when the DOPE-containing lipoplex was injected, whereas the Chol-containing lipoplex failed to induce any significant erythrocyte accumulation in the lung. In vitro experiments showed that the major fraction of both lipoplexes was bound to erythrocytes. These data suggested that Chol-containing lipoplexes bound to erythrocytes before injection dissociate from the erythrocytes and are transferred to the lung capillary endothelial cells during their passage through the lung. In contrast, DOPE-containing lipoplexes bound to erythrocytes cause aggregation and are embolized in the lung capillary with erythrocytes. Thus, the present study demonstrated that the interaction with erythrocytes plays an important role in the lung accumulation of lipoplexes and that neutral helper lipid significantly affects this interaction.

Prevention of neutrophil-mediated hepatic ischemia/reperfusion injury by superoxide dismutase and catalase derivatives

Our previous study demonstrated that the combination of mannosylated superoxide dismutase (Man-SOD) and succinylated catalase (Suc-CAT), both of which are designed to be targeted to liver nonparenchymal cells, is a promising approach to prevent the initial phase of hepatic ischemia/reperfusion injury induced by occlusion of the portal vein for 30 min followed by a 1-h reperfusion in mice. In this study, the preventive effects of these agents were examined on late-phase injury mediated by infiltrating neutrophils, a more severe condition than the initial one. Administration of Suc-CAT alone or with Man-SOD to mice undergoing hepatic ischemia/reperfusion significantly suppressed the expression of intercellular adhesion molecule-1 along the hepatic sinusoid and prevented neutrophil infiltration in the liver. Man-SOD and Suc-CAT also prevented the increase in plasma glutamic pyruvic transaminase and glutamic oxaloacetic transaminase activities after reperfusion lasting 3 and 6 h. Histological evaluation of liver tissues confirmed the efficacy of this treatment, suggesting that these SOD and catalase derivatives have the ability to suppress neutrophil-induced hepatic injury. These results demonstrate that targeted delivery of antioxidant enzymes to liver nonparenchymal cells is a promising approach to reducing the reactive oxygen species produced by Kupffer cells and neutrophils infiltrating into the tissue. Since Suc-CAT is partially taken up by hepatocytes via a catalase-specific uptake mechanism, such a fraction could also be involved in its preventive effect against the injury.

Transport characteristics of ebastine and its metabolites across human intestinal epithelial Caco-2 cell monolayers

The transport characteristics of a selective peripheral H1 receptor antagonist, ebastine, a substrate for cytochrome P450 3A4, and its three major metabolites, i.e., the hydroxy metabolite of ebastine (M-OH), the pharmacologically active metabolite carebastine (Car), and the desbutyrophenone metabolite (des-BP), were studied in cultured human intestinal Caco-2 cells expressing a drug efflux pump, P-glycoprotein (P-gp), on the apical membrane. The polarized transport of [3H]cyclosporin A (CyA), mediated by P-gp in the basolateral to apical direction across the Caco-2 cell monolayers, was affected by the presence of ebastine in a concentration-dependent manner and significant inhibition was observed at high concentrations (>50 microM). M-OH (300 microM) also significantly inhibited whereas Car and des-BP did not. Although no marked polarized transport of [14C]ebastine in a secretory direction was observed in the Caco-2 systems, the flux in the basolateral to apical direction was slightly higher than that in the opposite direction at concentrations less than 30 microm. [14C]Ebastine (2 microM) uptake from the apical side was significantly increased in the presence of an excess of cold CyA, suggesting that the efflux process mediated by P-gp may be involved in the ebastine uptake by Caco-2 cells. Collectively, these results indicate that ebastine (and presumably M-OH) is transported via P-gp in Caco-2 cells, however, the affinity for P-gp is very low. It is unlikely that the secretory transport of ebastine mediated by P-gp will dramatically affect overall intestinal absorption in vivo because efficient passive diffusion of this drug should occur due to its high lipophilicity. However, it may be advantageous for its efficient first-pass metabolism.

Neurohistochemical analysis of regeneration in rat peripheral nerve after end-to-side neurorrhaphy

We investigated the regenerative capacity of motor nerves repaired by end-to-side or end-to-end neurorrhaphy, using choline-acetyltransferase (ChAT) activity measurement or histological analysis. The right medial gastrocnemius nerves (MGNs) of 62 male Fisher strain rats were transected and divided into three groups. In group 1, the distal ends of the MGN were coapted to the side of the lateral gastrocnemius nerve, using a Y-shaped silicone tube in end-to-side neurorrhaphy. In group 2, the nerve ends were reconnected by the traditional end-to-end technique. In group 3, the nerve ends were separated and remained unrepaired. The MGNs were sampled 1, 2, and 3 months postoperatively for histological examinations and ChAT activity measurement. The medial gastrocnemius muscle (MGM) was also sampled for histological evaluations. Axonal regeneration of MGN and the recovery of MGM to nearly normal histology and weight were observed in groups 1 and 2 3 months postoperatively. Although there were no significant differences in ChAT values between groups 1 and 2, the values were significantly larger than that of group 3 3 months postoperatively. These findings suggested that end-to-side neurorrhaphy would be an alternative treatment for peripheral nerve injury in certain clinical situations.

Optical resonance in a narrow slit in a thick metallic screen

Interaction of TM-polarized waves with a subwavelength thick metallic slit has been analyzed. A Fabry-Pérot-like behavior is reported. The resonance peaks, however, have very low magnitude and a systematic shift towards longer wavelengths is observed. The slit being narrow, this shift can be interpreted as the result of an aperture effect. Spectral transmission from a periodic array of such slits features the same peaks with a high increase in their magnitude, confirming that a grating acts as an amplifier of those resonances. Such a mechanism might explain the enhancement of the transmission observed in recent experiments [T. W. Ebbesen, H. J. Lezec, H. F. Ghaemi, T. Thio, and P. A. Wolff, Nature (London) 391, 667 (1998)].

Hepatic uptake and gene expression mechanisms following intravenous administration of plasmid DNA by conventional and hydrodynamics-based procedures

Hepatic uptake and gene expression mechanisms following intravenous administration of naked plasmid DNA (pDNA) by conventional and hydrodynamics-based procedures were studied in mice. After conventional (normal) intravenous injection, (32)P-labeled pDNA was rapidly eliminated from the circulation and predominantly taken up by the liver nonparenchymal cells while no significant gene expression was observed in this organ. The hepatic uptake process was saturable. Involvement of a specific mechanism was demonstrated since the hepatic uptake of [(32)P]pDNA was dramatically inhibited by cold pDNA, calf thymus DNA, and some polyanions [polyinosinic acid (poly I), dextran sulfate], but not by others (polycytidylic acid, chondroitin sulfate). The liver endothelial cells appeared to be a major contributor because gadolinium chloride (GdCl(3))-induced Kupffer cell blockade did not affect the hepatic uptake. After intravenous injection of naked pDNA with a large volume of saline at a high velocity (hydrodynamics-based procedure), the apparent hepatic uptake profile was similar to that after normal injection. The hepatic uptake was not inhibited by prior administration of polyanions, including poly I, dextran sulfate, and heparin. The hydrodynamics-based procedure resulted in marked gene expression in the liver, which was not inhibited by prior administration of polyanions or GdCl(3) treatment. These results indicate that pDNA uptake is a nonspecific process. This hypothesis was supported by the finding that significant hepatic uptake of bovine serum albumin and immunoglobulin G was observed after the hydrodynamics-based procedure.

Biliary excretion of polystyrene microspheres depends on the type of receptor-mediated uptake in rat liver

Hepatic uptake and biliary excretion of fluorescein isothiocyanate-labeled polystyrene microspheres with a particle size of 50 nm (MS-50) were studied in rats. Liver perfusion studies revealed that not only apo-E-mediated but also asialoglycoprotein receptor-mediated uptake is involved in the mechanism of the serum protein-dependent uptake of MS-50 in the liver. The uptake of MS-50 mediated by apo-E contributes more to the total uptake of MS-50 by the hepatocytes than that via asialoglycoprotein receptor in the presence of serum in the perfusate. Furthermore, it was found that MS-50 is substantially excreted into the bile by transcytosis. The extent of exocytosis of MS-50 taken up by the hepatocytes was much higher after MS-50 was endocytosed via asialoglycoprotein receptor than after taken up via the process mediated by apo-E. On the basis of these results, a possible regulation of the intracellular sorting of ligands, depending on the receptor-mediated uptake mechanism, was inferred.

Interaction between DNA-cationic liposome complexes and erythrocytes is an important factor in systemic gene transfer via the intravenous route in mice: the role of the neutral helper lipid

Recent studies have indicated that there are many barriers to successful systemic gene delivery via cationic lipid vectors using the intravenous route. The purpose of this study was to investigate the effect of binding and interaction between erythrocytes, a major constituent of blood cells, and the complexes, in relation to the role of the helper lipid, on the in vivo gene delivery to the lung following intravenous injection. We used three types of cationic lipid vectors, DNA-DOTMA/Chol liposome complexes, DNA-DOTMA liposome complexes, and DNA-DOTMA/DOPE liposome complexes. Although the three types of vectors bind to murine blood cells in vivo and in vitro, DOTMA/Chol and DOTMA complexes with a higher in vivo transfection activity do not induce fusion between erythrocytes, whereas DOTMA/DOPE complexes, a less efficient vector in vivo, induce fusion between the erythrocytes after a short incubation period. Pre-incubation of DOTMA/DOPE complexes with erythrocytes significantly reduced the transfection efficiency while DOTMA/Chol- and DOTMA complexes were more resistant to such treatment. The differences in the physicochemical and structural properties of these complexes could explain the differences in interaction with erythrocytes and subsequent gene expression. Lipids in DOTMA/Chol and DOTMA complexes have a stable lamellar structure. However, lipids in DOTMA/DOPE complexes have a highly curved structure with high fluidity. These results indicate that the interaction with erythrocytes depends on the properties of the cationic lipid vectors and this is an important factor for intravenous gene delivery using cationic lipid vectors.

In vivo recognition of mannosylated proteins by hepatic mannose receptors and mannan-binding protein

In vivo recognition of mannosylated proteins by hepatic mannose receptors and serum mannan-binding protein (MBP) was investigated in mice. After intravenous administration, all three different (111)In-mannosylated proteins were taken up mainly by liver, and uptake was saturated with increasing doses. (111)In-Man-superoxide dismutases and (111)In-Man(12)- and (111)In-Man(16)-BSA had simple dose-dependent pharmacokinetic profiles, whereas other derivatives ((111)In-Man(25)-, -Man(35)-, and -Man(46)-BSA and (111)In-Man-IgGs) showed slow hepatic uptake at <1 mg/kg. Purified MBP experiments in vitro indicated that these derivatives bind to MBP in serum after injection, which interferes with their hepatic uptake. To quantitatively evaluate these recognition properties in vivo, a pharmacokinetic model-based analysis was performed for (111)In-Man-BSAs, estimating some parameters, including the Michaelis-Menten constant of the hepatic uptake and the dissociation constant of MBP, which correlate to the affinity of Man-BSAs for mannose receptors and MBP, respectively. The dissociation constant of Man-BSA and MBP decreased dramatically with increasing density of mannose, but the Michaelis-Menten constant of hepatic uptake of Man-BSA was not so sensitive to the change in density. This suggests that the in vivo recognition of MBP has a stronger cluster effect than that of mannose receptors. Differences obtained here are due to the unique arrangement of carbohydrate recognition domains on each mannose-specific lectin available for mannosylated ligand recognition.

Viability of ischemia/reperfused bone determined at the gene expression level

Rat bone viability was evaluated, using a bone viability index (BVI) that reflects mRNA degradation. To evaluate ischemic injury of the bone, 28 amputated hind limbs of Fischer rats (ischemic insult group: four subgroups, each containing seven limbs) were preserved at normothermia for 1, 3, 6 and 9 hr and the tibiae were harvested. To investigate ischemia/reperfusion injury, another 42 amputated limbs were transplanted to recipient Fischer rats after ischemia at normothermia for 1, 3 and 6 hr, respectively. The tibiae from the transplanted limbs were harvested on day 3 and day 7 after the transplantation (ischemia/reperfusion group). Seven fresh tibiae were also harvested and used as controls (control group). The total RNA isolated from the tibia of each group was fractionated by electrophoresis and hybridized with 32P-labelled cDNA of glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and the radioactivity of intact and degraded GAPDH mRNA was measured. BVI was calculated as follows: BVI = [A/(A + B)] x 100, where A and B represent the radioactivities corresponding to the intact GAPDH and degraded GAPDH mRNA band, respectively. In the 1-hr and 3-hr ischemia groups, the BVIs of the ischemia/reperfused group were comparable to those of controls, although the indexes of the ischemic insult group were significantly lower than controls. However, in the 6-hr ischemia group, indexes of both the ischemic insult and ischemia/reperfusion groups were significantly lower than controls. These results demonstrated that bone damage was detected with ischemia at normothermia even after 1 hr; however, this tissue damage was overcome by reperfusion. There was no recovery from damage in bones that had been preserved for more than 6 hr, resulting in irreversible degeneration. Therefore, in clinical vascularized bone grafts, it appears that transplantation should be done within a 3-hr ischemic period for it to be successful.

Development of gene drug delivery systems based on pharmacokinetic studies

A series of pharmacokinetic studies following systemic or local administration for the development of delivery systems for gene drugs, such as plasmid DNA and oligonucleotides, are reviewed. The pharmacokinetics of gene drugs after intravenous injection into mice was evaluated based on clearance concepts. Pharmacokinetic analysis revealed that the overall disposition characteristics of the gene drug itself were determined by the physicochemical properties of its polyanionic DNA. Based on these findings, liver cell-specific carrier systems via receptor-mediated endocytosis were successfully developed by optimizing physicochemical characteristics. On the other hand, the pharmacokinetics of gene drugs after intratumoral injection were assessed in a tissue-isolated tumor perfusion system. The relationship between the physicochemical properties of gene drug delivery systems and intratumoral pharmacokinetics was determined and the therapeutic effect was also discussed in relation to pharmacokinetics. Collectively, it was demonstrated that a rational design of gene drug delivery systems that can control their in vivo disposition is possible by means of pharmacokinetic studies at whole body, organ and cellular levels.

Relationship between meniscal degeneration and element contents

The purpose of this study is to investigate the relationship between meniscal degeneration and element contents. The contents of elements (calcium, phosphorus, sulfur, and magnesium) in the menisci from 17 patients with osteoarthritis (OA) of the knee, 6 with rheumatoid arthritis (RA), and 2 who underwent the surgical operation for malignant tumors (control) were analyzed by inductively coupled plasma-atomic emission spectrometry, and the menisci were divided into four stages (Stage 0-3) of histological degeneration. The calcium contents of the menisci were 0.26 +/- 0.16 in Stage 0, 0.50 +/- 0.37 in Stage 1, and 0.69 +/- 0.66 in Stage 2, respectively (the values represent mg elements/g dry tissue). They increased with the progression of the stage. This tendency was found in the menisci with OA, but was not clear in those with RA. The calcium content in the control group was 0.17 +/- 0.09 mg/g. There was no significant relationship between the stage of degeneration and the contents of phosphorus, sulfur, or magnesium. The calcium content of the meniscus might indicate the degree of meniscal degeneration.

[The relationship between beta 3-adrenoceptor and regulation of body fat mass, and food intake]

beta 3-adrenoceptor(beta 3-AR) plays important roles in thermogenesis of brown adipose tissue(BAT) and lypolysis of white adipose tissue(WAT). Anti-obesity effect of beta 3-agonists is reported, and the Trp64Arg point mutation of the human beta 3-AR gene is associated with abdominal obesity. beta 3-agonist decreases food intake in rat and mice, and its effect is confirmed by both direct infusions to the brain and peripheral injections. Stimulated thermogenesis of BAT increases glucose utilization, then 'glucose dip' signals meal initiation. Risen core temperature leads to meal termination. But, because of decreased ability for thermogenesis, meal size increases in many obese animal models. Further investigations are being carried out to make these problems clear.