The platinum ball a new embolic material

SUMMARY

Polyvinyl alcohol (PVA) particles have been widely used as an embolic material for endovascular treatment of vascular enriched tumors, especially for meningiomas. However, there are disadvantages with their use due to the fact that they are radiolucent, with a very irregular shape and a tendency for self-adhesion. With alternative organic liquids there is also a possibility of toxicity. We have therefore developed a new embolic material, platinum balls, which feature radioopacity, a relatively well-defined oval shape, multi-pitted and indented surfaces on electron microscopy and a lower tendency for self-adhesion Based on positive findings in experimental studies, embolization of meningiomas was conducted with platinum balls in 27 patients and the results compared with findings for a matched group previously treated with PVA particles.Total volume of blood transfused during surgery was comparable in the two cases, although a tendency for lower values was noted with the platinum balls, and outcome was equally positive.

Geranylgeranylacetone inhibits formation and function of human osteoclasts and prevents bone loss in tail-suspended rats and ovariectomized rats

Vitamin K is used for protecting against osteoporosis. Recently, it has been reported that the inhibitory effect of vitamin K(2) (menatetrenone) on bone resorption may be related to its side chain. Geranylgeranylacetone (GGA), known as teprenone, an antiulcer drug, has almost the same chemical structure as that of the side chain of menatetrenone. We hypothesized that GGA also has an inhibitory effect on osteoclastogenesis both in vitro and in vivo. GGA in pharmacological concentrations directly inhibited osteoclastogenesis from human monocytes induced by soluble receptor activator of nuclear factor-kappaB ligand. In addition, GGA induced degradation of actin rings in mature osteoclasts, which was reversed by adding geranylgeranylpyrophosphatase. Moreover, GGA increased the bone mineral density of total femur, proximal metaphysis, and diaphysis of femur in ovariectomized rats. GGA also prevented bone loss induced by hindlimb unloading in tail-suspended rats. These results indicate that GGA prevents bone loss by maintaining a positive balance of bone turnover through suppression of both the formation and the activity of osteoclasts. Thus, GGA could be used to prevent and improve osteoporosis.

Application of the liquid coil as an embolic material for arteriovenous malformations

SUMMARY

The purpose of this paper is to clarify advantages and disadvantages of platinum liquid coils as an embolic material for AVMs. During the last eight years, 50 endovascular procedures using liquid coils were conducted in our institute for 19 cases with AVMs, 15 of which were located in the eloquent area. All but one presented with haemorrhage, the exception demonstrating repeated ischemic symptoms. Only liquid coils were used as the embolic material to obliterate the nidus and feeders. In ten of the 15 patients with AVMs located in the eloquent area and one case rejecting surgery, liquid coil embolization was applied one to 11 times (average 3.5 times) to achieve decrease in size and this was then followed by radiosurgery. The remaining eight AVM patients underwent total removal after liquid coil embolization. No complications were encountered during the peri-embolization period. In all cases, the purpose of embolization was to diminish the size to facilitate radiosurgery and decrease bleeding during surgery. The liquid coil has advantages as a material for embolization of AVMs; it is non-toxic and bioinart material; it seldom occludes normal minute vascular channels; when it used in a nidus, it seldom to migrates in the venous direction, and it has good radio-opacity and offers good marking for surgery. Appropriate applications include preoperative embolization or pre-radiosurgical embolization of AVMs, especially when staged embolizations are performed to reduce risk of perfusion pressure breakthrough in patients which are large or located in the eloquent area.

A survey of Japanese patients with Menkes disease from 1990 to 2003: incidence and early signs before typical symptomatic onset, pointing the way to earlier diagnosis

Menkes disease (MNK) is a lethal, X-linked recessive disorder of copper metabolism dominated by neurodegenerative symptoms and connective tissue disturbances. The incidence of MNK in Asia is not known. Most patients die by the age of 3 years if adequate treatment is not carried out. Early parenteral administration of copper can prevent the neurological disturbances and lead to a better outcome. In the present study, a survey on MNK in Japan was performed. There were in total 53 live-born Japanese patients with MNK collected from 1990 to 2003, including two females. The incidence of live-born MNK patients between 1992 and 2002 was 2.8 per million live births (95% confidence interval (CI): 1.8 to 3.7), 4.9 per million male live births (95% CI: 3.2 to 6.6). One-third of the patients were born before 37 weeks or weighing less than 2500 g. Seventeen per cent were born both before 37 gestational weeks and weighing less than 2500 g. These proportions were higher than those in Japanese live-birth babies according to a nationwide estimate. The hair on these Japanese patients appeared not only as white or grey but also brown and blond. We also found that many signs had been noted before the patient was brought to a hospital with typical symptoms. These signs may be a clue to early diagnosis of MNK.

Histochemical evaluation for the biological effect of menatetrenone on metaphyseal trabeculae of ovariectomized rats

To evaluate the biological effects of vitamin K2 (menatetrenone, MK-4) on ovariectomy (OVX)-induced bone loss, we have examined histological alterations of femoral metaphyses of sham-operated (sham group), ovariectomized (OVX group), and MK-4 dietary-supplemented OVX (MK-4 group; 50 mg/kg per day) female Fischer rats 1, 2, 5, and 8 weeks after OVX. In the first week, rats of the OVX and MK-4 groups showed discontinuous trabeculae compared with sham-operated rats. At 2 weeks after OVX, the OVX rats revealed many large tartrate resistant acid phosphatase (TRAP)-positive osteoclasts, while osteoclasts in the MK-4-treated rats were similar in size to those of the sham group. At 5 weeks, the OVX and MK-4 groups revealed fragmented trabeculae in femoral metaphyses. The cartilage matrix was partially exposed due to stimulated bone resorption in the OVX group, but not in the MK-4 group. After 8 weeks, the OVX rats had little metaphyseal trabeculae, whereas the MK-4-treated rats had maintained short trabeculae. Despite the presence of intense alkaline phosphatase-positive osteoblasts on trabeculae in the MK-4 group, TRAP-positive osteoclasts were flattened without developing ruffled borders. Therefore, MK-4 appeared to lessen the increase in osteoclastic bone resorption induced by OVX, as well as to maintain the accelerated osteoblastic activity. It is of importance to identify the target cells for MK-4 in bone. Autoradiography localized [3H]-labeled MK-4 mainly in osteoblasts and adjacent bone matrices, but not in osteoclasts, indicating that MK-4 targets osteoblasts. Thus, MK-4 appears to target osteoblasts, consequently inhibiting bone loss induced by ovariectomy.

An X-ray outburst from the rapidly accreting young star that illuminates McNeil's nebula

Young, low-mass stars are luminous X-ray sources whose powerful X-ray flares may exert a profound influence over the process of planet formation. The origin of the X-ray emission is uncertain. Although many (or perhaps most) recently formed, low-mass stars emit X-rays as a consequence of solar-like coronal activity, it has also been suggested that X-ray emission may be a direct result of mass accretion onto the forming star. Here we report X-ray imaging spectroscopy observations which reveal a factor approximately 50 increase in the X-ray flux from a young star that is at present undergoing a spectacular optical/infrared outburst (this star illuminates McNeil's nebula). The outburst seems to be due to the sudden onset of a phase of rapid accretion. The coincidence of a surge in X-ray brightness with the optical/infrared eruption demonstrates that strongly enhanced high-energy emission from young stars can occur as a consequence of high accretion rates. We suggest that such accretion-enhanced X-ray emission from erupting young stars may be short-lived, because intense star-disk magnetospheric interactions are quenched rapidly by the subsequent flood of new material onto the star.

Neurotoxic potential of haloperidol in comparison with risperidone: implication of Akt-mediated signal changes by haloperidol

The neurotoxicity of conventional antipsychotic drugs has emerged as a potential pathogenic event in extrapyramidal side effects (EPS) and in their limited efficacy for negative-cognitive symptoms in schizophrenic patients. The atypical antipsychotics, recently developed, have superior therapeutic efficacy to treat not only positive symptoms but negative symptoms and cognitive dysfunctions with much lower potentials of side effects, although the influence of atypical antipsychotics on the regulation of neuronal survival has been less investigated. It is important to clarify the effects of typical and atypical antipsychotics on neuronal survival and their contributions to the therapeutic development and understanding of the pathophysiology of schizophrenia. We measured the neurotoxicity of two antipsychotic drug treatments, haloperidol and risperidone, in primary cultured rat cortical neurons. Immunoblotting and pharmacological agent analyses were used to determine the signal transduction changes implicated in the mechanisms of the neurotoxicity. Haloperidol induced apoptotic injury in cultured cortical neurons, but risperidone showed weak potential to injure the neurons. Treatment with haloperidol also led the reduction of phosphorylation levels of Akt, and activated caspase-3. The D2 agonist bromocriptine and 5-HT2A antagonist, ketanserin attenuated the haloperidol-induced neuronal toxicity. Moreover, brain-derived neurotrophic factor (BDNF) reduced the caspase-3 activity and protected neurons from haloperidol-induced apoptosis. BDNF also reversed the reduced levels of phosphorylation of Akt caused by treatment with haloperidol. Haloperidol but not risperidone induces caspase-dependent apoptosis by reducing cellular survival signaling, which possibly contributes to the differential clinical therapeutic efficacy and expression of side effects in schizophrenia.

Impairment of G(salpha) function in human brain cortex of Alzheimer's disease: comparison with normal aging

We examined the quantity and quality of G proteins in membrane preparations of post-mortem human brain, i.e. in parietal, temporal and occipital cortical regions, from normal subjects over age (17-89 years old) and with Alzheimer's disease (AD) in comparison with aged-matched controls. In normal aging, the immunoreactivities determined of G(ialpha), G(qalpha) and G(beta) were inversely correlated with age. The function of G proteins was examined by photoaffinity GTP analogue [azidoanilido GTP (AAGTP)] labelling. AAGTP labelling to G(salpha) and G(i/oalpha), and the ratio of G(salpha) to G(i/oalpha) AAGTP labelling showed no age-dependent changes. In AD compared to age-matched controls, there were no significant differences in the levels of G(sHalpha), G(sLalpha), G(ialpha), G(oalpha), G(qalpha) and G(beta) subunits. Functional effects of G proteins, however, as measured by AAGTP labelling to G(salpha), but not to G(i/oalpha), was significantly decreased in AD compared to controls in the parietal and temporal cortex, but not in the occipital cortex. These results suggest that the disturbances of post-receptor trans-membrane signalling in AD can be attributed to functional changes of G(salpha), and these are independent of alterations in the level for those proteins in normal aging.

Reduced phosphorylation of cyclic AMP-responsive element binding protein in the postmortem orbitofrontal cortex of patients with major depressive disorder

In this study, we examined the amounts of cAMP-responsive element binding protein (CREB) and its phosphorylated form in homogenate preparations from postmortem orbitofrontal cortices of antidepressant drug-free patients with major depressive disorder and age-matched controls by immunoblotting. Immunoreactivies of both CREB and phosphorylated CREB were significantly decreased in depressive subjects compared to controls. The immunoreactivity of phosphorylated CREB was diminished to a greater extent than that of CREB in depressive patients. It has been indicated from animal studies that a transcription factor likely mediates neural plasticity in the mammalian brain and neural tissues. Our results suggest that alterations in the cAMP signaling system, especially in CREB, may be involved in the pathophysiology of depression and be potential targets for antidepressant treatment.

[Total arch replacement for right aortic arch with Kommerell diverticulum and aberrant left subclavian artery]

A 57-year-old man suspected of having angina pectoris underwent coronary angiography and comprehensive examination, which revealed a right-side aortic arch accompanying Kommerell diverticulum and a aberrant left subclavian artery. Esophagography indicated that the esophagus was compressed on its right posterior side and the computed tomography (CT) revealed that the posterior side of the tracheal was compressed, however, the patient experienced no difficulty in breathing, hoarseness of voice or dysphasia. The size of the aortic diverticulum was less than 5 cm and the patient showed no symptom, however, if it was left untreated, there was a risk of rupture in the future. Also the esophagus and tracheal may develop complications due to prolonged compression. Therefore, we decided that the case required surgical operation. Total arch replacement was performed through mediastinotomy and right posterolateral in the 4th intercostal. The postoperative condition was good, and the patient was discharged without any complications.

[Early and mid-term results of all arterial graft coronary artery bypass grafting using bilateral internal thoracic and radial arterial conduits]

From March 1996 to May 2000, 41 patients [age 39-78 (mean 63.5 +/- 8.8) years, 90.2% male] underwent all arterial multiple coronary artery bypass grafting (CABG) using bilateral internal thoracic (BiITA) and radial (RA) arterial conduits. The reason for using RA was that the right gastroepiploic artery (RGEA) was small or occluded on preoperative angiography, a history of upper abdominal surgery or disease, or the right coronary arterial lesion was proximal and mild. The BiITA were used as in situ grafts and the proximal anastomosis of RA was to the ascending aorta in all cases. All patients underwent conventional elective CABG with median sternotomy using cardiopulmonary bypass. The mean number of anastomoses was 3.3 +/- 0.5 branches and complete revascularization rate was 80.5%. Postoperative follow-up averaged 20 months and the longest was 50 months. There was no early death, and overall graft patency 2-3 weeks after surgery was 96.2% (LITA 94.0%, RITA 97.6%, RA 97.6%). Four-year actuarial survival rate was 96.4 +/- 3.5% (1 patient: 9 months, no cardiac death), and cardiac event-free rate after surgery was 89.7 +/- 4.9% [4 patients: percutaneous transluminal coronary angioplasty (PTCA)]. However, once patients were discharged from hospital, cardiac event-free rate was 100%. These excellent results suggest that all arterial graft CABG was satisfactory, and RA can be used as a third suitable arterial bypass conduit, if RGEA cannot be used or is unsuitable for use.

Annexin-1 (lipocortin-1)-immunoreactivity in the folliculo-stellate cells of rat anterior pituitary: the effect of adrenalectomy and corticosterone treatment on its subcellular distribution

In the pituitary gland, annexin-1 (lipocortin-1) located in folliculo-stellate (FS) cells has been advocated as one of the candidates for paracrine agents produced by FS cells that modulate the release of pituitary hormones. However, the expression and distribution pattern of annexin-1 in FS cells under different circulating corticosteroid conditions has not been examined. Thus, by means of pre-embedding immunoelectron microscopy, we investigated the expression of annexin-1 in FS cells under different corticosteroid conditions. Annexin-1-immunoreactivity was observed in the cytoplasm; especially intense immunoreactivity was detected in the follicle surface of FS cells under control conditions. After adrenalectomy, annexin-1-immunoreactivity almost disappeared, but the immunoreactivity recovered with corticosterone replacement. The expression of glucocorticoid receptor immunoreactivity in the nucleus of FS cells also showed a similar pattern to annexin-1 associated with the changes in the corticosteroid conditions. However, S-100 immunoreactivity, a marker for FS cells, was not changed whatever the corticosteroid conditions. These results confirm that glucocorticoids regulate the annexin-1 expression and demonstrate the translocation of annexin-1 from intracellular to pericellular sites in the FS cells of the rat anterior pituitary gland.

Langerhans cell expression of neuropeptide Y and peptide YY

Neuropeptide Y (NPY) and peptide YY (PYY) are structurally related peptides with a variety of known functions. The role of these peptides in the skin is largely unknown, although NPY-like immunoreactivity has been reported in the epidermis. The recent report that these peptides have antimicrobial properties suggests that NPY and PYY may contribute to the skin's defense mechanisms against invading microorganisms. We have demonstrated that Langerhans cells (LC) and a certain BALB/c epidermis-derived dendritic cell line contain mRNA for NPY and PYY using RT-PCR. Furthermore, this dendritic cell line as well as an epidermis-derived dendritic cell line from A/J mice were found to produce NPY and PYY and LC produced PYY, as assessed by radioimmunoassay. These data suggest that the protective function of LC include not only antigen presentation, but also production of antimicrobial peptides.

[A 50-year history of new drugs in Japan: the developments and trends of antihyperlipidemic drugs]

The developments and trends of antihyperlipidemic drugs and their effects on the mortality of coronary heart disease in Japan were investigated. The developed drugs available for hyperlipidemia were recorded with their approval dates by the Ministry of Health and Welfare (Table 1). 1. Antihyperlipidemic drugs have been developed since the late 1950s. Useful drugs among them include the fibrate series and the statin (HMG-CoA reductase inhibitor) series. Clofibrate, developed in 1965, was the first fibrate drug, and pravastatin sodium (Mevalotin(R) Sankyo Co.), developed in 1989, was the first statin drug. They have sure effectiveness for lowering serum cholesterol and triglyceride. But they induce an unfavorable side-effect, rhabdomyolisis, especially after the continuous or simultaneous use of both. The other drug classes using hyperlipidemia include various different types, e.g., probucol, nicotinates, anion exchange resins, ethyl icosapentate, and dextran sodium sulfate. Despite their mild activities, the low incidence of adverse effects make them suitable for supplementary use with fibrates or statins. 2. "Guideline for Diagnosis and Treatment of Hyperlipidemia in Adult" was presented by the Japan Atherosclersis Society in 1997. The standard criteria of serum cholesterol and triglyceride levels in Japanese adults were proposed. The hypercholesterolemia is the state of more than a 220 mg/dl level of serum cholesterol, and hypertriglyceridemia is of more than a 150 mg/dl level of serum triglyceride. The pharmacotherapy should be applied for a high serum level of cholesterol exceeding 240 mg/dl. But the standard routine formula of drug therapy were not indicated in the present guideline. 3. Epidemiological surveys show that hyperlipidemia induces coronary heart diseases in the United States, European countries, and Japan. The mortality of all heart disease patients in Japan increased rapidly from the late 1960s, but the mortality resulting from coronary heart disease was suppressed from 1968. This suppression continued throughout 1994 when artificial statistical changes occurred. It may be due to the newly developed antihyperlipidemic drugs, e.g., the clofibrate group, the statin series, and others (Fig.2).

Different modes of action of catecholamine-O-methyltransferase inhibitors entacapone and tolcapone on adenylyl cyclase activity in vitro

Catechol-O-methyltransferase (COMT) inhibitors such as entacapone and tolcapone are used as adjuncts to L-DOPA ( l-3,4-dihydroxyphenylalanine, levodopa) in the treatment of Parkinson's disease. Tolcapone has been reported to associate with diarrhoea, a common reason for study withdrawal. The mechanism of this adverse effect is not yet understood. Cholera toxin causes diarrhoea by permanent activation of G(s) proteins, resulting in increased adenylyl cyclase (AC) activity. The aim of this study was to examine the effects of the COMT inhibitors entacapone and tolcapone on AC activity in membranes isolated from rat striatum, a brain structure enriched with dopaminergic G-protein-coupled receptors and AC activity. This study demonstrates differential effects of tolcapone and entacapone on Gpp(NH)p/dopamine-stimulated AC activity. Entacapone enhanced the stimulatory effect of Gpp(NH)p/dopamine, whereas tolcapone attentuated this effect, suggesting that diarrhoea associated with tolcapone treatment is not caused by permanent activation of G(s) proteins.

Ultrastructural analysis of bone calcification by using energy-filtering transmission electron microscopy

In order to elucidate the mechanisms of bone calcification, embryonic rat calvariae treated with chemical or cryo-fixation were observed using transmission electron microscopy by three techniques: fine structures, various cvtochemical localizations including nonspecific proteoglycan, decorin, chondroitin 4-sulfate, hyaluronan, alkaline phosphatase (ALP), and osteonectin, as well as the elemental mapping of calcium and phosphorus by energy-filtering electron microscopy. In the calvariae, the calcification sequence ran as follows crystallization within matrix vesicles, formation of calcified nodules, collagen calcification, and finally the establishment of an expansive calcified matrix. The osteoid contained an abundance of mesh-like fibers of proteoglycans, including decorin, chondroitin 4-sulfate, and hyaluronan, around collagen fibrils approximately 50 nm in diameter. Calcium tended to localize at the proteoglycan sites, while phosphorus was often mapped to the collagen fibril-structures in the osteoid. Calcium/phosphorus co-localization was found in and around the calcified nodules, where ALP and small sized proteoglycans were observed. During this stage, native proteoglycans surrounding the collagen fibrils disappeared, with the collagen fibrils fusing laterally, and attaining a diameter of more than 400nm. The calcified nodules expanded to occupy the entire space made available by the collagen fibril-fusion, following osteonectin accumulation in the calcified nodule/collagen fibril border. In conclusion, crystals present within the matrix vesicles became calcified nodules, in a process induced by the co-localization of calcium and phosphorus. ALP and proteoglycans may participate in the calcium/phosphorus co-localization. Decreases in the native proteoglycans, and the lateral fusion of collagen fibrils are thought to be involved in the expansion of calcified areas, followed by osteonectin-mediated collagen calcification.

Steroid effects on secretion from subsets of lactotrophs: role of folliculo-stellate cells and annexin 1

Prolactin secretion is controlled by the hypothalamus, and by circulating steroids; oestrogens stimulate, but glucocorticoids inhibit prolactin release. Lactotrophs express intracellular receptors for oestrogens, but apparently not glucocorticoids. Therefore, a genomic effect of oestrogens could be direct, but that of glucocorticoids appears to be indirect. Lactotrophs are not a homogeneous cell population: some have large irregular dense-cored vesicles, others have small round vesicles, but the functional significance of this inhomogeneity is far from clear. Oestradiol and testosterone can stimulate rapid release of prolactin selectively from type II lactotrophs characterised by small round vesicles. Progesterone and other steroids do not exert this effect, which results from a non-genomic action of oestradiol and testosterone. Glucocorticoid inhibition of secretagogue-induced prolactin secretion is mimicked by annexin 1 (lipocortin 1), a protein induced by glucocorticoids in the pituitary and many other tissues, and can be blocked by annexin 1 immunoneutralisation and antisense. Glucocorticoid inhibition of ACTH and growth hormone secretion also involves annexin 1. Pituitary annexin 1 is located in folliculo-stellate cells; these express glucocorticoid receptors, and glucocorticoids induce annexin-1 synthesis. Annexin 1 is externalised from folliculo-stellate cells in response to glucocorticoids, despite the fact that it lacks a secretory signal sequence and is not packaged in vesicles. Inhibition of annexin 1 externalisation by glyburide suggests involvement of an ABC (ATP-binding cassette) transporter in externalisation. Both oestradiol and glucocorticoids therefore influence the secretion of prolactin by novel direct and indirect mechanisms, in addition to their much better understood effects on transcription via classical intracellular steroid receptors.

Effects of ovariectomy on trabecular structures of rat alveolar bone

An association between postmenopausal osteoporosis and tooth loss has been proposed. However, histomorphometrical changes in alveolar bone following estrogen deficiency are rarely reported with data on microtrabecular structural changes. To clarify the relationship between estrogen deficiency and tooth loss, we histomorphometrically analyzed the trabecular structural changes of mandibular alveolar bone in ovariectomized rats. Twenty-four adult female Fischer rats were used. Eight rats were sacrificed on day 0 (baseline). The remaining 16 rats were divided into two groups. One group was ovariectomized bilaterally (OVX) and the other group was subjected to sham surgery (Sham). After administration of tetracycline and calcein, the animals were sacrificed 60 days after surgery. Bone histomorphometry, node-strut analysis and measurement of thickness of alveolar bone proper were performed on the interradicular septum of the first molar on the sagittal surface. The trabecular bone volume and trabecular number of the OVX group were significantly lower than those of the baseline and Sham groups. All of the bone resorptive and formative parameters of the OVX group were significantly higher (about one-and-a-half times) than those of the Sham group. Several osteoclasts were seen lining the irregular, eroded surface facing the bone marrow in the OVX group. Furthermore, the OVX group tended to have low microtrabecular stiffness and showed significantly thinner distal alveolar bone proper than in the baseline and Sham groups. In summary, estrogen deficiency caused osteoporotic changes and thin alveolar bone proper in the interradicular septum of rat first molar. This phenomenon might accelerate destruction of alveolar bone and tooth loss, especially in elderly women affected by periodontal disease.

Nitric oxide synthase gene therapy for erectile dysfunction: comparison of plasmid, adenovirus, and adenovirus-transduced myoblast vectors

BACKGROUND AND PURPOSE

Nitric oxide (NO) has been recognized as an important transmitter for genitourinary tract function. This transmitter mediates smooth muscle relaxation and is essential for erection. The objective of our research was to determine whether overexpression of nitric oxide synthase (NOS) in the corpus cavernosum of the penis would correct erectile dysfunction.

MATERIALS AND METHODS

We introduced the inducible form of the enzyme NOS (iNOS) into the corpus cavernosum of adult (250-300 g) male Sprague-Dawley rats by injecting a solution of plasmid, adenovirus, or adenovirus-transduced myoblast cells (adeno-myoblast) (N = 3-5 each group). We also injected plasmid, adenovirus, and adeno-myoblast encoding the expression of the beta-gatactosidase reporter gene.

RESULTS

We noted expression of beta-galactosidase throughout the corpora cavernosum after injection of each of the three solutions. Staining was greatest for adeno-myoblast followed by adenovirus and then plasmid. The basal intracavernous pressure (ICP) of iNOS-treated animals (adenovirus and adenovirus-transduced myoblast) increased to 55 +/- 23 cm H(2)O v 5 +/- 6 H(2)O in naive animals (P = 0.001). Stimulation of the cavernous nerve (15 Hz, 1.5 msec, 10-40 V, 1 min) resulted in a twofold increase in ICP (adenovirus and adeno-myoblast) from the basal level of the iNOS-treated animals. Direct in situ measurement of NO demonstrated release of 1 to 1.3 microM NO in the adeno-myoblast-treated penis.

CONCLUSION

Myoblast-mediated gene therapy was more successful in delivering iNOS into the corpus cavernosum than were the direct adenovirus or plasmid transfection methods. Gene therapy of NOS may open new avenues of treatment for erectile dysfunction. Control of NOS expression would be necessary to prevent priapism.

Immunolocalization of osteoclast differentiation factor in rat periodontium

The aim here was to observe the immunohistochemical localization of osteoclast differentiation factor (ODF)/receptor activator of NF kappa B ligand (RANKL) in the rat periodontium. Rat mandibles were demineralized and embedded in paraffin, and horizontal and frontal sections were prepared for immunohistochemical analysis. In horizontal sections, immunolocalization of RANKL was marked in the distal area of the periodontium of molars in which osteoclasts appeared, due to physiological tooth drift. In frontal sections, RANKL immunoreactivity was localized on spindle-shaped mesenchymal cells around blood vessels near the bone surface in the periodontium. In addition, immunoreaction for RANKL was detected on structures that appeared to be elongated cell processes near blood vessels in frontal sections. Immunohistochemical examination for the general antigen of nerve-specific protein suggested a similarity between these structures and nerve fibres.

Effects of oestrogen deficiency on osteoclastogenesis in the rat periodontium

This study was designed to investigate quantitative changes in osteoclast generation in rat periodontium following ovariectomy. Wistar rats, aged 9 weeks, were subjected to either ovariectomy (OVX) or sham surgery. Osmotic pumps were implanted in 24 rats and either 17beta-oestradiol or vehicle solution were infused continuously. The rats were assigned to one of the following groups: (1) OVX+vehicle; (2) sham+vehicle; or (3) OVX+ 17beta-oestradiol. On the days 7 and 14 after surgery, four rats in each group were killed. Mandibles were demineralized and embedded in paraffin. Frontal sections of alveolar bone in the region of the first molar were cut for enzyme histochemistry and immunohistochemistry. On day 7, there was no significant difference in the number of tartrate-resistant acid phosphatase (TRAP)-positive cells located on bone surfaces in either group. However, the number of TRAP-positive mononuclear cells that were separated from the bone surface was significantly higher in group 1 than in groups 2 and 3. On the day 14, the number of TRAP-positive cells in group 1, which were attached to the bone surface, was significantly higher than had been apparent on day 7. There were also significant increases in the number of nuclei of TRAP-positive cells attached to the bone in group 1 compared with groups 2 and 3 on day 14. These findings demonstrate that oestrogen deficiency induces of osteoclastogenesis in the rat periodontium and that quantitative changes in osteoclastogenesis could be prevented by E2 infusion.