Enhanced expression of endothelial oxidized low-density lipoprotein receptor (LOX-1) in hypertensive rats

Oxidized low-density lipoprotein (Ox-LDL) has been implicated in the attenuated endothelium-dependent vasodilatation in atherosclerotic arteries and, possibly, in hypertension. The aim of the present study was to investigate gene expression of recently-identified endothelial Ox-LDL receptor (LOX-1) in hypertensive state. SHR-SP, WKY, Dahl salt-sensitive (DS) and salt-resistant rats (DR) were fed salt-loaded or control diet. RNA was extracted from the aorta and vein. LOX-1 expression was examined by Northern blotting. LOX-1 mRNA was low in the aorta and vein of WKY, whereas it was markedly upregulated in those of SHR-SP. LOX-1 expression was low in the aorta of DR on both diets and of DS on a control diet, whereas it was elevated in that of salt-loaded DS. These results indicated that LOX-1 expression in the aorta and vein was upregulated in hypertensive rats, which may be involved in the impaired endothelium-dependent vasodilation in these rats.

Role of natriuretic peptide receptor type C in Dahl salt-sensitive hypertensive rats

The natriuretic peptide system is suggested to be involved in the pathogenesis of salt-sensitive hypertension; a recent report indicated that disruption of the atrial natriuretic peptide precursor gene caused salt-sensitive hypertension. However, natriuretic peptide receptor (NPR)-A knockout mice did not show enhanced salt sensitivity of blood pressure. The aim of the present study was to investigate the role of NPR-C, the other receptor for atrial natriuretic peptide, in increased salt sensitivity of blood pressure. Dahl salt-sensitive (DS) and salt-resistant (DR) rats were placed on a 0.3% or 8% NaCl diet for 4 weeks. Blood pressure was elevated by salt loading only in DS rats. RNase protection assay demonstrated that NPR-C transcript level in the kidney was reduced by chronic salt loading in both DR and DS rats, whereas expression of NPR-A and NPR-B was not altered. The reduction of NPR-C mRNA in response to salt loading was enhanced in DS compared with DR rats. In situ hybridization indicated that the salt-induced NPR-C change was attributed mainly to suppressed expression of NPR-C in the podocytes. NPR-C gene expression was regulated by salt loading in a tissue-specific manner; the marked decrease in NPR-C mRNA by salt loading was seen only in the kidney. These data suggest that the exaggerated salt-induced reduction of NPR-C in the kidney of DS rats may play an important role in the pathogenesis of salt hypertension in this animal, possibly related to impaired renal sodium excretion.

[Do angiotensin converting enzyme and calcium channel blocker intervene in the progression of renal disease besides by lowering systemic hypertension?]

Systemic hypertension is accompanied by various renal diseases. Lowering of blood pressure is widely recognized effective for slowing further decline of renal function. Angiotensin converting enzyme inhibitor (ACEI) and calcium channel blocker (CCB) have recently emerged as antihypertensive drugs endowed with renoprotective action directed specifically to the kidney. Improvement of glomerular hypertension which is more remarkably observed in ACEI than in CCB, is thought to be a factor responsible for renoprotection. Although this effect is widely shown in experimental models, consensus has not yet been reached as to whether this effect as well as the therapeutic efficacy are really exerted in various clinical settings other than diabetic nephropathy.

[A case of anti-basement membrane (BM) mediated disease presenting renal and pulmonary symptoms by divergent timing]

A case of 49-year-old man with anti-GBM antibody and who manifested pulmonary and renal symptoms at divergent times. Thirty-six years previously, renal disease with unneglectable degree of proteinuria was noticed. One month before admission, he was found by chance to have elevated serum creatine (Scr); 3.4 mg/dl. At admission, his Scr was 13.7 mg/dl and Hb 12.7 g/dl, TP 5.2 g/dl with 3+ proteinuria and no glucosuria. He was a heavy smoker and remained so while admitted. Renal biopsy presented fibrocellular crescents in 100% of glomeruli with striking tubulointerstitial involvement. Immunofluorescence showed linear IgG deposition along the glomerular capillary wall. Hemodialysis was instituted, and after 13 hospital days, anti-GBM antibody at admission was high at 128 U, with negative PANCA. Plasmapheresis was also performed, but on the next day pulmonary hemorrhage occurred with a concomitant rise of anti-GBM to 250 U. Thus, steroid pulse therapy was conducted in combination with plasmapheresis. Pulmonary hemorrhage subsided along with lowering of anti-GBM (48 U), but renal failure persisted. The patient died of septicemia. Based on the clinical course of the case, the term "anti-BM mediated disease" may more properly delineate the entity of the disease rather than the classical eponym "Goodpasture's disease" which requires coexistence of pulmo- and renal manifestations for definition.

Long-term effect of manidipine on renal function and structure in uninephrectomized spontaneously hypertensive rats

1. Long-term effects of manidipine hydrochloride (MAN), a calcium channel blocker, were examined in three groups of spontaneously hypertensive rats (SHR). Group 1 was given uninephrectomy (UNX) and MAN treatment, group 2 was given UNX and was not treated with MAN and group 3 was given neither UNX nor MAN treatment. 2. At week 15 after UNX, inulin clearance in group 1 rats decreased compared with rats in groups 2 and 3, but remained at the same level at week 40, when the level in group 2 rats declined below that in rats in groups 1 and 3. 3. Glomerular and tubulointerstitial lesions did not differ at week 15 after UNX among the three groups, whereas at week 40 both were advanced in the order of groups 2, 1 and 3. 4. Proteinuria did not differ between rats in groups 1 and 2 over the experimental period. 5. At week 15, the kidney weights of group 1 rats were greater than those of group 2 rats, indicating more prominent tubular hypertrophy in the former group. This was confirmed by morphometry of the proximal tubuli. In contrast, the glomerular volumes of rats in groups 1 and 2 were enlarged compared with that of rats in group 3, with no difference between the former two groups. 6. The findings suggest that MAN exerts renoprotective effects in SHR, both with regard to function and morphology. An effect on glomerular haemodynamics was considered to more likely be the mechanism underlying the renoprotective effect of MAN rather than that of a lowering of systemic blood pressure. 7. Augmented tubular hypertrophy after MAN treatment was an unexpected finding of the present study and the biological significance of this finding remains to be explored.

Glomerular handling of immune complex in the acute phase of active in situ immune complex glomerulonephritis employing cationized ferritin in rats. Ultrastructural localization of immune complex, complements and inflammatory cells

The ultrastructural localization of immune complex (IC) and inflammatory mediator systems in the glomerulus was investigated in active in situ IC glomerulonephritis employing cationized ferritin in rats. Glomerulonephritis was induced by unilateral renal perfusion of cationized ferritin as antigen (Ag) in preimmunized rats, and anti-ferritin antibody (Ab), C3 and the rat C5b-9 complex were localized by means of immunogold electron microscopy. Ag-Ab complexes were initially formed subendothelially, associated with C3, and attracted platelets, polymorphonuclear leucocytes (PMN) and monocytes. Then Ag-Ab complexes, without C3, passed across the glomerular basement membrane to re-aggregate subepithelially accompanied by C3 deposition after 1 day. Ag-Ab complexes without C3 accumulated in the inter-podocyte space within 1 day and were seen in the epithelial cells at 6 h. C5b-9 complexes were found in subepithelial immune deposits and in membrane vesicles of the epithelial cells, but only in very small amounts in subendothelial immune deposits. Accumulated platelets, PMN, and monocyte were in direct contact with endothelial cells or subendothelial IC. PMN and monocytes contained Ag, Ab and C3 in intracytoplasmic vacuoles. Ag-Ab complexes were also found in the mesangial matrix adjacent to the subendothelial region after 2 h and increased slightly in number, with expansion of the mesangial area thereafter. Most ICs formed in the subendothelial space rapidly formed lattices of a size that activated C3 and were then translocated to the subepithelial space. The potential ability of C3 to solubilize ICs in the subendothelial region may be important in this process. Endocytosis of subendothelial ICs by PMN and/or monocytes and the movement of ICs to the mesangial matrix may also contribute to the removal of IC from the subendothelial space.

In vivo effect of OPC15161, a superoxide scavenger, on anti-Thy1 nephritis

The in vivo effect of 6-(1 H-indol-3-ylmethyl)-5-methoxy-3-(2-methylpropyl)-2(1 H)-pyrazinone, 4-oxide (OPC15161), a superoxide scavenger, was studied in rats with anti-Thy1 nephritis. Rats were divided into 4 groups: G-1, normal control; G-2, anti-Thy1 nephritis; G-3 anti-Thy1 nephritis and treated with OPC15161 (50 mg/kg/day) starting at day 0; and G-4, anti-Thy1 nephritis and treated with OPC15161 starting 3 days before antibody injection. At weeks 2 and 8, rats were killed for morphological study and at week 8 for renal clearance. Results were compared among the 4 groups. OPC15161 suppressed urinary albumin/day. Total glomerular cells, mesangial cells, ED-1-positive cells/glomerulus and glomerular volume all increased and the increases were suppressed by OPC15161. Tubulointerstitial index, assessed by point counting, was improved by OPC15161 (P < 0.05 G-3, 4, vs. G-2, not significant vs. G-1). Glomerular filtration rate decreased in all nephritic animals, but the decrease in renal blood flow was less in the treated groups. These findings indicate a favorable effect of OPC15161 on the glomerular and interstitial lesions of anti-Thy1 nephritis.

Effects of repeated treatment with methamphetamine plus scopolamine and methamphetamine on behavioral sensitization and conditioning

This study compared repeated treatment with methamphetamine (4.0 mg/kg, i.p.) plus scopolamine (0.5 mg/kg, i.p.) and methamphetamine alone in behavioral sensitization and drug conditioning with respect to a reciprocal balance between the dopaminergic and cholinergic systems. Repeated methamphetamine plus scopolamine treatment induced a more progressive and enduring enhancement of stereotyped behavior than repeated methamphetamine treatment. Methamphetamine plus scopolamine-induced stereotyped behavior was reproduced by challenge injections of not only methamphetamine plus scopolamine and methamphetamine, but also, to a lesser extent, by scopolamine challenges. The methamphetamine plus scopolamine-sensitized rats were conditioned to a low-frequency tone (300 Hz, 100 dB) as conditioned stimulus associated with the drug state. They responded to pairings of the tone and placebo injections, but not to the tone alone or the placebo alone. The methamphetamine-sensitized rats failed to exhibit conditioning. These results suggest that methamphetamine plus scopolamine-induced pronounced behavioral sensitization may produce an enhanced conditioning. Exteroceptive conditioned stimulus-interoceptive unconditioned stimulus associations may provide an important source for drug conditioning. We concluded that behavioral sensitization may be mediated via a reciprocal balance between the dopaminergic and cholinergic systems, in favor of a dopaminergic dominance. Conditioning to the drug-associated tone may operate via a reciprocal balance between the dopaminergic and cholinergic systems.

Local renin-angiotensin system in sympathetic overactivity of spontaneously hypertensive rats

The present study was designed to clarify whether modulation of norepinephrine (NE) release by vascular angiotensin (Ang) II is involved in the increased peripheral sympathetic activity of spontaneously hypertensive rats (SHR). In the perfusion system of isolated mesenteric vascular beds, periarterial nerve stimulation (PNS)-evoked NE overflow was significantly greater in SHR than Wistar-Kyoto rats (WKY). Administration of Ang II increased PNS-induced NE overflow, which could be reversed by pretreatment with the AT1 receptor antagonist CV-11974 in both types of rats; the facilitation by Ang II was more potent in SHR. Moreover, CV-11974 by itself could attenuate PNS-evoked NE overflow, the extent of which was also significantly greater in SHR, suggesting an augmented sympatho-facilitatory effect of endogenous Ang II in SHR. Consistently, sympatho-facilitation by Ang I, which could be abolished by the angiotensin converting enzyme (ACE) inhibitor imidaprilat, was apparently greater than that of Ang II in SHR, despite no difference in WKY. These findings suggest that the increased peripheral sympathetic activity in SHR is attributed not only to the elevated sensitivity of nerve endings to Ang II but also to the increased local generation of Ang II, an effect possibly mediated by augmented vascular ACE activity.

Differential effects of different forms of hydroxyapatite and hydroxyapatite/tricalcium phosphate particulates on human monocyte/macrophages in vitro

A possible complication associated with the use of hydroxyapatite (HA) or HA/tricalcium phosphate (HA/TCP) coating on the surfaces of prosthetic devices used for dental and orthopedic implants is their potential to fragment and thus exist as wear debris. In contrast to the so-called osteoconductive properties of HA or HA/TCP coatings, in particulate form these materials may lead to an adverse pattern of cellular and tissue responses at the bone-implant interface. We have established an in vitro cell culture system to characterize the biologic and biochemical effects of various particulate materials. The present study demonstrates that the HA/TCP particles derived from different sintering temperatures exhibit differential effects on cultured human monocyte/macrophages (M/M). The HA/TCP particles dried at 110 degrees C were the most biologically active, stimulating significant release of interleukin 1 beta (IL-1 beta), IL-6, tumor necrosis factor alpha, and prostaglandin E2 (PGE2), products implicated as important mediators of inflammation in diverse pathologic conditions. Other particles, sintered at either 900 or 1200 degrees C, did not stimulate production of cytokines or PGE2. HA/TCP particles from plasma-spray coatings also failed to release proinflammatory products. These results suggest that the biochemical and crystalline structural properties of particles markedly affects their capacity to modulate M/M function. This in vitro culture system should be useful in characterizing the specific physical and chemical properties of HA or HA/TCP particulates that are responsible for stimulating proinflammatory cell responses.

Interactions of nicardipine to inhalation anesthetics sevoflurane and isoflurane

The hemodynamic effects and pharmacokinetics of nicardipine under general anesthesia were compared between two different volatile anesthetics, sevoflurane and isoflurane. Sixteen adult neurosurgery patients were divided into sevoflurane and isoflurane groups. Anesthesia was maintained with either sevoflurane or isoflurane (0.5-1.5%) and nitrous oxide in oxygen. When the blood pressure was stabilized [0.5 minimum alveolar concentration (MAC) in both anesthetics] during surgery, nicardipine 1 mg, i.v. was administered. Plasma catecholamines and nicardipine concentration were measured, and the pharmacokinetics of nicardipine were calculate. The decrease in blood pressure and the increase in heart rate 30 min after nicardipine administration were significant in the isoflurane group but not in the sevoflurane group. Although plasma catecholamine levels increased after nicardipine administration in the isoflurane group, no significant changes were observed in the sevoflurane group. The sevoflurane group had a significantly longer elimination half-life, a larger area under the plasma concentration curve, and smaller clearance of nicardipine compared to the isoflurane group. In summary, the effects of nicardipine on blood pressure and heart rate were significantly longer under isoflurane anesthesia than under sevoflurane anesthesia. However, the etabolism and excretion of nicardipine were significantly delayed under sevoflurane anesthesia.

Comparison of behavioural effects of repeated treatment with methamphetamine plus scopolamine and methamphetamine alone on behavioural sensitization and conditioned response

We investigated how repeated treatments with methamphetamine (4.0 mg kg-1, i.p.) plus scopolamine (0.5 mg kg-1, i.p.) and methamphetamine alone effected behavioural sensitization and conditioned response in rats. Repeated methamphetamine plus scopolamine treatment induced a more progressive and enduring enhancement of focused stereotyped behaviour than repeated methamphetamine treatment. Stereotyped behaviour induced by methamphetamine plus scopolamine was reproduced by challenge injections of methamphetamine plus scopolamine, methamphetamine, and to a lesser extent by scopolamine challenges. The methamphetamine plus scopolamine-sensitized rats were conditioned to a low frequency tone (300 Hz, 100 dB) associated with the drug state. They exhibited a conditioned response to pairings of the tone (conditioned stimulus) and placebo injections. However, they did not respond to the tone alone or the placebo injections alone. The methamphetamine-sensitized rats failed to demonstrate any conditioning; only the repeated methamphetamine plus scopolamine treatment induced sensitization to the drug-associated tone. Pairings of exteroceptive conditioned stimulus-interoceptive unconditioned stimulus associations may provide an important source for conditioning to the tone associated with the drug state. We conclude that behavioural sensitization may operate via a reciprocal balance between the dopaminergic and cholinergic inhibitory systems, in favour of a dopaminergic dominance. Conditioning to the drug-associated tone may be mediated via a reciprocal balance between the two transmitter systems.

Strain variation in susceptibility to the development of monoclonal antibody 5-1-6-induced proteinuria in rats

Susceptibility to the development of MoAb 5-1-6-induced proteinuria was investigated in four different rat strains, i.e. Brown-Norway (BN), Lewis (LEW), Sprague-Dawley (SD) and Wistar. An intravenous injection of 5 mg of MoAb 5-1-6 to female 7-week-old rats of a given strain induced massive proteinuria in BN, LEW and Wistar rats. However, SD rats developed almost no proteinuria. A similar tendency was observed in the second experiment, in which the injected dose of MoAb was adjusted according to the body weight of each rat (3 mg/100 g body weight). Immunofluorescence (IF) and immunoelectron microscopy (IEM) revealed no differences between the binding patterns of the MoAbs to normal rat kidneys derived from each strain. Quantitative study using 125I-labelled MoAb showed that there was no significant difference in the amount of antibody bound to the kidney 1 h and 5 days after injection between two rat strains, LEW and SD. Localization of 5-1-6 in vivo and its kinetics were investigated. In IF a linear-like pattern along capillary walls was observed 2 h after injection in both LEW and SD strains. This linear-like pattern was shifted to a granular pattern in proteinuric LEW rats 6 days after injection, whereas it remained linear-like in non-proteinuric SD rats. IEM confirmed this difference in the localization of injected MoAb 6 days after injection to LEW and SD rats also at the ultrastructural level. We conclude that there is a clear-cut strain difference in the development of proteinuria induced by MoAb 5-1-6. SD rats were less susceptible to MoAb-induced glomerular injury than BN, LEW and Wistar rats. Although the exact reason for strain variation in susceptibility to MoAb-induced proteinuria remains to be clarified, the movement of bound MoAb, presumably together with corresponding antigenic molecule along the glomerular epithelial cell surface followed by endocytosis into the epithelial cell, seems to be closely related to the induction of proteinuria.

Determination of tributyltin and triphenyltin compounds in hair and fish using a hydrolysis technique and gas chromatography with flame photometric detection

A hydrolysis technique and a GC method are described for the determination of tributyltin and triphenyltin compounds in human hair and fish tissue. A sample was hydrolysed with a potassium hydroxide-ethanol-water solution. Tributyltin and triphenyltin compounds in the hydrolysate were extracted with toluene, and then impurities in the extract were eliminated with anion- and cation-exchange resins. After propylation of the organotin compounds, a yellow impurity was removed with a Sep-Pak florisil cartridge, and the two propylated organotin compounds were separated using a silicone OV-1 GC column and determined by flame photometric detection. The limits of determination of tributyltin and triphenyltin compounds in the sample were 5 and 10 ng g-1, respectively, in their chloride forms. The recoveries of tributyltin chloride from hair samples were 78.8 and 90.8%, respectively, when the spiked amounts were 20 and 200 ng. The recoveries of triphenyltin chloride from hair samples were 71.7 and 72.7%, respectively, when the spiked amounts were 40 and 400 ng. The recoveries of the organotin compounds from fish were similar to the recoveries from hair.

Methamphetamine plus scopolamine potentiates behavioral sensitization and conditioning

The effects of repeated methamphetamine (4.0 mg/kg) plus scopolamine (0.5 mg/kg) treatment on behavioral sensitization and drug conditioning in rats were compared with the effects of repeated methamphetamine treatment. Behavioral sensitization induced by repeated methamphetamine plus scopolamine treatment was more vigorous than that induced by repeated methamphetamine treatment. Repeated methamphetamine plus scopolamine treatment produced sensitized responses, not only to methamphetamine plus scopolamine and methamphetamine but also, to a lesser extent, to scopolamine. Methamphetamine plus scopolamine-sensitized rats but not methamphetamine-sensitized rats exhibited conditioned responses to a low-frequency tone (300 Hz, 100 dB) associated with the drug state, suggesting that robust methamphetamine plus scopolamine-induced behavioral sensitization may lead to enhanced conditioning. It is plausible that robust behavioral sensitization might operate via a reciprocal balance between the dopaminergic and cholinergic systems in favor of dopaminergic dominance. Conditioning to the drug-associated tone may be mediated via a reciprocal balance between the two transmitter systems.

Malignant squamous cell carcinoma arising in a lumbar dermoid cyst. A case report

A case of malignant transformation to a squamous cell carcinoma in a long-standing lumbar dermoid cyst is described. Progress was slow during 6 years. This type of transformation in a dermoid cyst is extremely uncommon and has never been recorded at this site.

[Anesthesia for SUMO wrestlers]

We anesthetized 34 sumo wrestlers. All patients were male. Average age was 21.1. Their height was 181.9 +/- 4.5 (mean +/- SD) cm, and they weighted 135.2 +/- 16.9 kg. Anesthetic methods used were spinal anesthesia alone in 17 patients, general anesthesia alone in 9, general anesthesia + epidural anesthesia/or spinal anesthesia/or axillary block in 8. The preoperative data showed findings common to obese patients; liver dysfunction, abnormal blood sugar, and abnormal ECG such as ST depression or left ventricular hypertrophy. For intubation, fiberscopy was required in one patient, and almost all patients required high FIO2, otherwise SaO2 decreased. For spinal anesthesia or epidural anesthesia, we needed long needles of 8 to 15 cm.

pH-dependent inactivation and reactivation of recombinant sheep angiotensinogen

Purified recombinant sheep angiotensinogen (rsAngn) lost 74% of the reactivity with human renin during storage at pH 8.0 and 4 degrees C. The inactivated rsAngn was reactivated by incubation at acidic pHs. This indicates that pH-dependent inactivation and reactivation occur in rsAngn.

Strychnine poisoning: natural course of a nonfatal case

A rare case of suicidal strychnine poisoning that resolved naturally without treatment is presented. The patient first complained of chest pain, which was originally thought to be caused by a dissecting aneurysm; however, nystagmus, dysesthesia, spastic paraplesia, and hyperreactivity to stimuli shortly developed. Diagnosis was difficult because the patient did not disclose the drinking of strychnine or the suicidal intent, and no abnormal signs were seen in the various central nervous system examinations. The natural course was observed without treatment because the patient's circulatory and respiratory condition was good. Movement disturbances in the upper extremities disappeared after 2 days, nystagmus in 3 days, and dysesthesia and spastic paraplesia in 4 days. The patient was able to stand on the fourth day and walk on the seventh. He was discharged on day 10 without any detectable ill effects.

[Postoperative pain relief by patient controlled analgesia using intravenous pentazocine]

Patient controlled analgesia (PCA) by intravenous pentazocine was performed to determine its efficacy and the dose required for the pain relief after gynecological or obstetric operations. After obtaining informed consent, studies were performed on 28 female patients (ASA I, II: Mean age 38.1 years: Mean weight, 53.8 kg) who had received gynecological or obstetric operations with lower abdominal incision. Anesthesia given was nitrous oxide and isoflurane combined with epidural anesthesia with 1% mepivacaine used only during the operation. Six patients had cesarian section under spinal anesthesia. No patients received opioid during anesthesia. PCA was performed with a Graseby PCA pump. Lockout time was 8 minutes and the bolus dose was 3 mg. In all the patients, satisfactory pain relief was obtained and no other analgesic was necessary. Mean initial dose was 169.4 micrograms.kg-1 and the mean doses used for following each 6 hours until 24 hours were 409.7, 368.6, 279.3 and 211.1 micrograms.kg-1 respectively. Evaluation of PCA by the patients after the procedure showed excellent (13 patients) good (12) and passable (3) analgesia. No significant complication was observed except temporary nausea in two patients. Satisfactory postoperative pain relief could be obtained by relatively small doses of pentazocine and adverse reactions related especially to sigma receptor could be avoided.