Lipid-lowering and antiatherosclerotic effect of NK-104, a potent 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, in Watanabe heritable hyperlipidemic rabbits

NK-104 ((+)-monocalcium bis(3R,5S,6E)-7-[2-cyclopropyl-4-(4-fluorophenyl)-3-quinolyl]-3,5-dihydroxy- 6-heptenoate), CAS 147526-32-7) an inhibitor of 3-hydroxy-3-metylglutaryl coenzyme A reductase, was administered in drinking water (0.5 mg/kg equivalent) to Watanabe heritable hyperlipidemic (WHHL) rabbits for 26 weeks. It lowered plasma total cholesterol (TC, 7-20%) and triglyceride (TG, 16-39%) levels throughout the experimental period due to a significant reduction of very low density lipoprotein cholesterol (VLDL-C, 61-62%, p < 0.05), intermediate density lipoprotein cholesterol (IDL-C, 49-60%, p < 0.05), VLDL-TG (40-53%, p = 0.06-0.08) and IDL-TG (29-59%, p = 0.06-0.14); low density lipoprotein cholesterol (LDL-C) was not affected. The pattern of the lipoprotein reduction along with a decrease in liver cholesteryl ester (CE, 33.1%, p < 0.01) suggests an intense reduction of VLDL secretion and a marginal induction of LDL-receptor. Enhanced expression of LDL receptor-related protein (LRP) in the liver was observed at mRNA levels (49.5% increase, P = 0.13), which might play a role in the lipoprotein reduction. Histological analyses of aorta revealed that aortic arch showed the most advanced lesions with larger lesion area (70.0 vs 41.3%) and much greater CE content (more than 2 fold) with less macrophages than thoracic aorta. NK-104 decreased the surface lesion area at the arch (23.1%, p = 0.054) and reduced the degeneration of media in the thoracic aorta (69.9% increase in medial smooth muscle cells, p < 0.01). Thus NK-104 preferentially reduced TG-rich lipoproteins (VLDL and IDL) without affecting LDL-C levels and prevented progression of atherosclerosis in WHHL rabbits.

Overexpression of p27 protein in human breast cancer correlates with in vitro resistance to doxorubicin and mitomycin C

BACKGROUND

The cycle regulatory protein p27, an inhibitor of cyclin-dependent kinase (CDK), has been attributed a role in resistance to cancer chemotherapy. However, the predictive value of p27 for chemosensitivity of breast cancer is still unclear. We therefore analyzed the in vitro chemosensitivity to a series of anticancer agents in fresh breast cancer specimens and correlated it with the respective expression levels of p27.

MATERIALS AND METHODS

The expression of p27 protein was examined immunohistochemically in 119 patients with primary breast cancer. The in vitro chemosensitivity was assessed by the histoculture drug response assay (HDRA) using mitomycin C (MMC), 5-fluorouracil (5-Fu), Doxorubicin (DXR), cisplatin (CDDP) and cyclophosphamide (CPA).

RESULTS

Fifty-six (47%) of the 119 patients demonstrated p27 overexpression. The susceptibility of DXR and MMC in tumors with high p27 expression was significantly higher than that in tumors with low p27 expression.

CONCLUSION

Immunohistochemical results regarding p27 might be therapeutically useful as an indicator of response to DXR and/or MMC based adjuvant chemotherapy for breast cancer.

Effect of shear stress on platelet adhesion to expanded polytetrafluoroethylene, a silicone sheet, and an endothelial cell monolayer

We visualized in real-time platelets adhering to the surface of three representative biomaterials, by using an apparatus consisting of a modified cone and plate rheometer combined with an upright epifluorescence microscope under two shear flows (0.1 and 5.0 dyne/cm2). The materials were expanded polytetrafluoroethylene (ePTFE), silicone sheet, and a monolayer of bovine endothelial cells (ECs) formed on glass, all of which are opaque materials used for artificial blood vessels and medical devices. According to quantitative analysis, the monolayer of ECs formed on glass had better blood compatibility than did either the ePTFE or the silicone sheet under shear flow conditions. Under a shear flow condition of 0.1 dyne/cm2, platelet adhesion was silicone sheet > ePTFE. In contrast, under a shear flow condition of 5.0 dyne/cm2, ePTFE > silicone sheet. These results indicate that the intensity of shear stress could modify the order of hemocompatibility of the materials. Therefore, direct observation of platelet adhesion under shear flow conditions is indispensable for testing and screening biomaterials and for providing a precise quantitative evaluation of platelet adhesion.

Biomechanical functions of the iliolumbar ligament in L5 spondylolysis

Abiomechanical study of the functions of the iliolumbar ligament in L5 spondylolysis was performed. Five fresh cadaveric specimens were used. The bilateral ilia and sacrum were fixed. Four kinds of pure moments (10 Nm) were applied to the specimens at the top (L4) vertebra: flexion, extension, and right and left axial rotations. The three-dimensional position of the L5 vertebra was measured after serial transections in: (1) the intact condition; (2) bilateral pars interarticulares of L5 transected; (3) anterior bands of the iliolumbar ligaments transected; and (4) posterior bands of the iliolumbar ligaments transected. In L5 spondylolysis, flexion and axial rotation of L5 on S1 are significantly regulated by the anterior and posterior bands of the iliolumbar ligaments (especially by the posterior bands of the ligaments). The integrity of the ligament may determine the stability of the lumbosacral junction and the amount of forward slipping of the L5 vertebra.

Effect of endothelin-1 (1-31) on human mesangial cell proliferation

It was previously found that human chymase cleaves big endothelins (ETs) at the Tyr31-Gly32 bond and produces 31-amino acid ETs (1-31). In the present study, human plasma concentrations of ET-1 (1-31) and ET-1 were examined and the effect of synthetic ET-1 (1-31) on the proliferation of cultured human mesangial cells (HMCs) was investigated. The proliferative effect of ET-1 (1-31) was evaluated from the [3H]-thymidine uptake. The activity of extracellular signal-regulated kinase (ERK) and DNA binding activity of activator protein-1 were determined by using an in-gel kinase assay and gel mobility shift assay, respectively. Immunoreactive ET-1 (1-31) was detectable in plasma, but the level was slightly lower than that of ET-1. ET-1 (1-31) increased [3H]-thymidine incorporation in HMCs to a degree similar to that induced by ET-1. ET-1 (1-31) also activated ERK1/2. Inhibition of protein kinase C and ERK kinase caused a reduction of ET-1 (1-31)-induced ERK1/2 activation. The ERK1/2 activation was followed by an increase in transcription factor activator protein-1 DNA binding activity. These findings suggest that ET-1 (1-31) is a bioactive peptide in humans and ET-1 (1-31) itself stimulates HMC proliferation.

An immunosuppressive and anti-inflammatory HLA class I-derived peptide binds vascular cell adhesion molecule-1

BACKGROUND

A synthetic peptide corresponding to residues 75-84 of HLA-B2702 modulates immune responses in rodents and humans both in vitro and in vivo.

METHODS

We used a yeast two-hybrid screening, an in vitro biochemical method, and an in vivo animal model.

RESULTS

Two cellular receptors for this novel immunomodulatory peptide were identified using a yeast two-hybrid screen: immunoglobulin binding protein (BiP), a member of the heat shock protein 70 family, and vascular cell adhesion molecule (VCAM)-1. Identification of BiP as a ligand for this peptide confirms earlier biochemical findings, while the interaction with VCAM-1 suggests an alternative mechanism of action. Binding to the B2702 peptide but not to closely related variants was confirmed by ligand Western blot analysis and correlated with immunomodulatory activity of each peptide. In mice, an ovalbumin-induced allergic pulmonary response was blocked by in vivo administration of either the B2702 peptide or anti-VLA-4 antibody.

CONCLUSIONS

We propose that the immunomodulatory effect of the B2702 peptide is caused, in part, by binding to VCAM-1, which then prevents the normal interaction of VCAM-1 with VLA-4.

Reconstruction of the achilles tendon and overlying skin defect with a medical plantar flap and tensor fasciae latae graft

The authors report a case of Achilles tendon and skin defect treated with an island medial plantar flap and fascia lata graft with very satisfactory results.

Paclitaxel-induced remission in docetaxel-refractory anthracycline-pretreated metastatic breast cancer

Paclitaxel and docetaxel are excellent agents with a high antitumor effect for the treatment of previously anthracycline-exposed metastatic breast cancer. There has been no standard treatment for patients who undergo therapy of a taxan-resistant metastatic breast cancer. Paclitaxel has partial non-cross-resistance in vitro with docetaxel in inhibiting microtubule disaggregation. We present the case of a patient with docetaxel-refractory anthracycline-pretreated metastatic breast cancer who achieved remission with paclitaxel.

Pituitary stone--case report

A 50-year-old male with acromegalic features presented with a pituitary stone in a growth hormone-secreting adenoma. Endocrinological examination showed "low growth hormone acromegaly." The serum growth hormone level responded to the thyrotropin-releasing hormone test and was not suppressed by oral glucose loading. Neuroimaging revealed an adenoma including a large calcification (pituitary stone) located in the right lateral wing. The adenoma with stone was totally removed by transsphenoidal surgery. The patient regained almost normal response of serum growth hormone. Histological examination showed the stone was composed of thick calcification surrounded by necrotic adenoma tissue and chronic hemorrhage. Large intratumoral pituitary stone is very rare, although calcification is sometimes observed in the adenoma capsule. The long history of this disease and previous apoplexy within the tumor may have caused the pituitary stone in this patient.

[Metabolic acidosis and ketone body in severely head-injured patients]

Increase of ketone body concentration in plasma is induced by various factors such as onset of diabetes. Secretion of excessive stress hormone including catecholamine is responsible for stimulation of lipolysis which increases plasma ketone body concentration. Catecholamine levels reflect the severity of the neurologic insult, so this is a basis for the use of catecholamine measurements as a physiological marker of patient outcome. Twenty-seven patients with severe head injury and twenty-five healthy volunteers were enrolled in this study, but patients with diabetes or liver dysfunction were excluded. The patients with severe head injury consisted of 19 with focal injury and 8 with diffuse injury. The outcome was as follows; 14 patients died and 13 patients survived. We collected arterial blood samples as promptly as possible after onset of severe head injury and measured the following: 1, base excess; 2, beta-hydroxybutyrate; 3, acetoacetate; 4, lactate; 5, epinephrine; 6, norepinephrine. The ketone body (beta-hydroxybutyrate + acetoacetate) concentration in plasma was significantly elevated in patients with severe head injury. The increment of beta-hydroxybutyrate levels was greater than that of acetoacetate levels, resulting decreased arterial ketone body ratio (AKBR; acetoacetate/beta-hydroxybutyrate). We demonstrated that plasma ketone body concentrations were elevated and the AKBR decreased in severe head-injured patients. Elevation of catecholamine has been reported as a stress reaction in severe head injury. Catecholamine is most potent in stimulating lipolysis, and ketogenesis. Therefore, the ketonemia observed in severe head injury is most likely to be induced by elevation of catecholamine levels. The degree of ketonemia may be an index of the severity of severe head injury.

Role of leukocytes in radicular pain secondary to herniated nucleus pulposus

Some studies have assessed inflammatory cells such as macrophages, lymphocytes, and neutrophils in herniated lumbar disc tissues using histologic analysis. However, there is no consensus regarding the relationships between clinical symptoms, including radicular pain and the presence of inflammatory cells. It has been shown that autologous nucleus pulposus relocated on the lumbar nerve root in rats produces time dependent and reversible mechanical hyperalgesia, which is thought to be a pain related behavior in peripheral neuropathic pain models. The purpose of this study was to determine whether leukocytes play a role in the mechanical hyperalgesia induced by the nucleus pulposus and to characterize the role of leukocytes in radicular pain attributable to lumbar disc herniation. Nitrogen mustard was used to induce and evaluate leukocytopenia in rats. Sensitivity to mechanical noxious stimuli was measured quantitatively, and inflammatory cells in granulation tissue around the nerve root were examined histologically. The nucleus pulposus produced neither mechanical hyperalgesia nor abundant inflammatory cells in rats with nitrogen mustard induced leukocytopenia. Neuropathic pain produced by the nucleus pulposus, when placed on the nerve root, may be related to inflammatory cell infiltration induced by relocation of the nucleus pulposus, rather than the nucleus pulposus itself.

Regression of a presumed meningioma with the antiestrogen agent mepitiostane. Case report

This 68-year-old woman underwent a distal gastrectomy for gastric cancer in August 1994. A presumed meningioma of the falx was found incidentally on a staging examination of the gastric cancer, but the meningioma was not treated with surgery. Instead, after gastrectomy the patient received tegafur as adjuvant chemotherapy until February 1996, when she was readmitted to the hospital because of loss of appetite and emaciation but with no recurrence of the gastric cancer. A computerized tomography scan obtained during this second admission showed no change in the meningioma. To improve her general condition, tegafur was discontinued and she was started on a course of the antiestrogen agent mepitiostane. Administration of mepitiostane for approximately 2 years resulted in a marked regression (73%) of the meningioma. This is the first reported case of a presumed meningioma that regressed as a result of use of the antiestrogen agent mepitiostane.

Prior induction of heat shock proteins by a nitric oxide donor attenuates cardiac ischemia/reperfusion injury in the rat

BACKGROUND

Recent studies have demonstrated that nitric oxide (NO) releasers considerably increase heat shock proteins (HSPs) in the in vitro cell system, providing resistance to oxidant damage. This study was designed to examine the cellular responses of HSPs induced by prior administration of an NO releaser, FK409 (FK), in an in vivo transplantation model.

METHODS

Lewis rats received either saline or FK solution intravenously administered at different time points before graft harvesting (10 micromol/kg) or for 15 min during reperfusion (0.66 micromol/kg/min). Tissue specimens were taken to determine HSP70 and heme oxygenase-1/HSP32 (HO-1) expression, and glutathione content. After 24-hr preservation with University of Wisconsin solution, heterotopic cardiac transplantations were performed, and graft survival was determined at 14 days. Tissue samples for end labeling of nuclear DNA fragments (TdT-mediated d-uridine triphosphate biotin nick end labeling; TUNEL) and propidium iodide staining were taken 15 min after reperfusion.

RESULTS

The gene and protein expression of HSP70 after FK administration peaked at 12 min and 60-90 min, whereas those of HO-1 peaked at 6 min and 90 min, respectively. Then, representative cardiac grafts taken 60 min after FK treatment were examined for further assay. Localization of induced HSP70 and HO-1 molecules were observed in the myocardium and vascular endothelium, respectively. Prior treatment of FK was effective in preventing the reduction of tissue glutathione contents compared with control (P<0.05). Fewer TUNEL and propidium iodide-positive cells were also observed in the FK group (P<0.0005, vs. control). The graft survival rate was higher in the FK group (9/10 vs. 1/10 of control; P<0.001), whereas the groups either harvested 10 min after FK pretreatment or continuously infused for 15 min during reperfusion were inferior, similar to that of control.

CONCLUSION

Prior induction of HSP70 and HO-1 with a relatively low dose of FK administration attenuates ischemia and reperfusion injury, which was due to antioxidant and antiapoptotic activities augmented by such stress proteins. Thus, NO releasers as a pharmacological maneuver may provide an innovative approach for the prevention of ischemia and reperfusion injury.

Expression of Bcl-2 but not Bax or p53 correlates with in vitro resistance to a series of anticancer drugs in breast carcinoma

Programmed cell death is an important determinant of the response to chemotherapy. Among the factors controlling this process, a significant role is played by bcl-2, bax and p53. The in vitro chemosensitivity of the 177 breast carcinomas was assessed by the histoculture drug response assay (HDRA) using mitomycin C (MMC), 5-fluorouracil (5-Fu), adriamycin (ADM), cisplatin (CDDP), and cyclophosphamide (CPA). The susceptibility of Bcl-2-negative tumors to all the drugs killing was significantly higher than that of Bcl-2-positive tumors. No relationship between Bax or p53 immunoreactivity and sensitivity for any of anticancer drugs studied was demonstrated. Immunohistochemical results regarding Bcl-2 are promising in the evaluation of the sensitivity of cancer cells to a series of anticancer drugs and might be therapeutically useful as an indicator of response to adjuvant chemotherapy for breast cancer.

Limited myogenic response to a single bout of weight-lifting exercise in old rats

The purpose of the present study was to compare the myogenic response of hindlimb muscles in young (14-20 wk of age) and old (>120 wk of age) rats with a single exhaustive bout of heavy resistance weight lifting. [(3)H]thymidine and [(14)C]leucine labeling were monitored for up to 2 wk after the exercise bout to estimate serial changes in mitotic activity and the level of amino acid uptake and myosin synthesis. Histological, histochemical, and immunohistochemical [anti-5-bromo-2'-deoxyuridine and myogenic determination genes (MyoD)] analyses of whole muscles and analysis of muscle-specific gene expression (MyoD) using Western blotting and RT-PCR were performed. Old rats showed significant muscle atrophy and a lower exercise capacity than young rats. Exercise-induced muscle damage, as assessed in histological sections, and increases in serum creatine kinase activity were evident in both young and old exercised groups. Mitotic activity was increased in young, but not old, rats 2 days after exercise. There was a biphasic increase in [(14)C]leucine uptake during the 14 days postexercise (peaks at 1-4 and 10 days) in young rats: only the first peak was observed in old rats. There was a lower uptake of [(14)C]leucine in the myosin fraction and an impaired expression of MyoD at the protein (immunohistochemistry and Western blotting) and mRNA (RT-PCR) levels in old rats throughout the postexercise period. These results demonstrate a reduced reparative capability of muscle in response to a single bout of exercise in old compared with young rats.

Influence of the interosseous talocalcaneal ligament injury on stability of the ankle-subtalar joint complex--a cadaveric experimental study

The present study aims to clarify the influence of the interosseous talocalcaneal ligament (ITCL) injury associated with injury to the lateral ankle ligaments on the ankle-subtalar joint complex motion under conditions of physiologic loading. We conducted mechanical tests using five fresh cadaveric lower extremities. Each specimen was mounted in the loading device and an axial cyclic load from 9.8 to 686 N was applied. Three-dimensional rotations of the ankle and the subtalar joint were measured simultaneously by a linkage electric goniometer. Mechanical tests were repeated after sectioning of the anterior talofibular ligament (ATFL), and again after additional sectioning of the ITCL. In the intact condition, the ankle and the subtalar joints rotated consistently with increase of the load. The predominant rotations were plantar flexion and adduction at the ankle joint, with some eversion demonstrated at the subtalar joint. Although ATFL sectioning did not significantly change the motion of the two joints, additional sectioning of the ITCL significantly increased adduction and total rotation of the ankle joint. The present study demonstrated that a combined injury of the ATFL and the ITCL can induce anterolateral rotatory instability of the ankle joint under conditions of axial loading.

An experimental approach to spinal fusion using sintered bovine bone in a pig model

Sintered bovine bone is a biomaterial based on calcium phosphate, an organized crystal of bone mineral that possesses a natural trabecular structure. The authors considered whether sintered bovine bone can integrate with recipient bone and adjust to the strength of recipient bone for anterior spinal fusion in an animal model. Either autologous iliac bone or sintered bovine bone was implanted for a spinal body fusion. Some pigs underwent exposure of the spinal bodies without implantation. Based on radiographic evaluation, manual palpation, biomechanical testing, and histologic examination, spinal fusion with sintered bovine bone resulted in a composition and structure similar to that of the autograft (or of no implantation). The sintered bovine bone with its moderate strength tended to adjust to the bone stiffness of the host bone in the specimens as new bone grew.

[Pain relief with alendronate therapy in a breast cancer patient with bone metastasis]

A 66-year-old woman developed a bone metastasis from breast cancer to the sternum in September, 1997. She received alendronate therapy, consisting of biweekly intravenous administrations of 10 mg-alendronate 6 times and monthly 20 mg-alendronate infusions 15 times. The first alendronate administration markedly alleviated her bone pain. She obtained complete pain relief after the 4th alendronate infusion. However, an elevation of tumor marker levels in serum without any pain increase forced us to treat her with medroxyprogesterone acetate and doxifluridine in addition to the alendronate therapy. With these therapies, she has shown an objective response (PR) of the bone metastasis for 8 months. In conclusion, alendronate therapy was effective against bone pain due to metastasis of breast cancer.

Mechanical compression of the lumbar nerve root alters pain-related behaviors induced by the nucleus pulposus in the rat

The purpose of this study was to refine a method of nerve-root injury in the rat to produce hyperalgesia, a pain-related behavior, and to determine if there were any relationships between the histological extent of nerve-root injury and the magnitude of hyperalgesia. Three methods were used to produce hyperalgesia: irritation of a nerve root by ectopic nucleus pulposus, silk loop alone, or both silk loop and ectopic nucleus pulposus. Autologous nucleus pulposus obtained from coccygeal intervertebral discs was relocated on the lumbar nerve roots after laminectomy. Two loops of 4-0 silk were placed around the exposed nerve roots. Hyperalgesia was measured preoperatively and postoperatively. The distribution of myelinated axons in the dorsal nerve roots was evaluated histologically. Mechanical hyperalgesia was detected in rats in which autologous nucleus pulposus was applied to the nerve root but not in those in which silk loops were used. Silk loops around the nerve root resulted in thermal hyperalgesia only in rats in which autologous nucleus pulposus was applied to the nerve root. Fewer large myelinated fibers were seen in the rats in which silk loops were used. Although a silk loop around the nerve root was not sufficient to produce hyperalgesia, supplemental application of autologous nucleus pulposus to the nerve root produced thermal hyperalgesia. It is possible that mechanical constriction of the nerve root alters the pain-related behavior elicited by chemical factors from the nucleus pulposus.

Iatrogenic ulnar nerve injury after percutaneous cross-pinning of supracondylar fracture in a child

Supracondylar fracture of the humerus is the most common fracture of the elbow in children and has been treated by a variety of methods. Recently, stabilization of reduced fractures with percutaneous pin fixation has become the accepted method of treatment. Ulnar nerve injury is a complication of percutaneous pinning of supracondylar fractures, although many authors have reported that it resolves spontaneously after removal of the pin.