Preventive effect of sulphated colominic acid on P-selectin-dependent infiltration of macrophages in experimentally induced crescentic glomerulonephritis.

Leucocytes infiltrate into renal tissue and are involved in the pathogenesis of crescentic glomerulonephritis. The initial event in the process of leucocyte infiltration is characterized by selectin-mediated leucocyte rolling on endothelial surface. Role of selectins in pathogenesis of glomerulonephritis has still been controversial. Sulphated glycolipids and sulphated polysaccharides interfere with the binding of P- and L-selectin with carbohydrate ligands on endothelial cells or on leucocytes. Here we evaluated the role of selectins and the preventive effects of sulphated colominic acid (SCA), a synthetic sulphated polysaccharide, on experimental crescentic glomerulonephritis in Wistar-Kyoto (WKY) rats. Crescentic glomerulonephritis was induced by injection of nephrotoxic serum (NTS) in WKY rats. Rats subsequently received intraperitoneal injection of saline, neutralizing or non-neutralizing monoclonal antibody (mAb) to rat P-selectin and L-selectin, SCA (5 or 10mg/kg/day) or nonsulphated colominic acid (CA) (10mg/kg/day) for 2 weeks. Localization of P-, E-selectin, ligands for L-selectin and intraglomerular leucocytes was examined by immunohistochemistry. Gene expression of platelet-derived growth factor (PDGF) B chain in glomeruli was quantified using real-time RT-PCR. P-selectin was highly expressed on glomerular endothelial cells after injection of NTS, whereas E-selectin and L-selectin ligands were not detected. Anti-P-selectin mAb, but not anti-L-selectin mAb, significantly reduced glomerular infiltration of macrophages, crescent formation, and proteinuria. SCA also reduced proteinuria, macrophage infiltration, and crescent formation in a dose-dependent manner. Furthermore, SCA suppressed gene expression of PDGF B chain in glomeruli. Our results indicate that P-selectin partially mediates glomerular infiltration of macrophage in experimental crescentic glomerulonephritis. Moreover, SCA may inhibit intraglomerular infiltration of macrophages by interfering with P-selectin-dependent adhesion pathway, and progression of experimental crescentic glomerulonephritis.

Cloning of murine membrane-type-1-matrix metalloproteinase (MT-1-MMP) and its metanephric developmental regulation with respect to MMP-2 and its inhibitor.

BACKGROUND: Extracellular matrix macromolecules regulate morphogenesis of embryonic organs, and are developmentally regulated. Their expression and turnover is regulated by matrix metalloproteinases (MMPs). Recently, an epithelial cell "membrane" associated metalloproteinase (MT-1-MMP) has been identified that acts as an activator of a "secreted" MMP-2, and is produced by mesenchymal fibroblasts. The activity of MMP-2 is inhibited by a "soluble" tissue inhibitor of MMP-2, TIMP-2. The role of MT-1-MMP in renal development is unknown. METHODS: MT-1-MMP was cloned from embryonic mouse kidney cDNA library, and its spatio-temporal distribution during development in the context of MMP-2 and tissue inhibitor of metalloproteinase-2 (TIMP-2) was studied. RESULTS: The cloned MT-1-MMP exhibited approximately 86% nucleotide sequence homology with human MT-1-MMP, and had a catalytic domain and a zinc binding site preceded by a RRKR furin recognition motif. A approximately 4.5 Kb MT-1-MMP mRNA transcript was detected, and its expression was developmentally regulated. A parallel developmental regulation of MMP-2 mRNA expression was also observed. TIMP-2 expression was also developmentally regulated, but lagged behind MT-1-MMP and MMP-2. By in situ hybridization, MT-1-MMP mRNA was seen to be confined to ureteric bud epithelia, and was absent in the mesenchyme, while MMP-2 was confined to the mesenchyme. MT-1-MMP protein expression was seen on ureteric bud epithelia, induced mesenchyme and nascent nephrons, and it was highest during mid gestation. Similar spatio-temporal expressions of MMP-2 and TIMP-2 proteins were observed. CONCLUSIONS: mRNAs of MT-MMP-1 and MMP-2 are expressed in the respective epithelial and mesenchymal compartments, while their proteins are co-expressed in the epithelia suggest that MT-1-MMP and MMP-2, in conjunction with TIMP-2, may be involved in paracrine/juxtacrine epithelial:mesenchymal interactions during metanephrogenesis.

N-methyl-D-aspartate injection into the massa intermedia facilitates development of limbic kindling in rats.

The effect on limbic kindling of N-methyl-D-aspartate (NMDA) injection into the midline thalamus of rats was investigated. Repeated injection of 25 nmol/0.5 microliters NMDA (experimental group) into the massa intermedia (MI), particularly into the reuniens nucleus, caused tonic and/or clonic generalized convulsion associated with temporal limbic EEG seizure discharge. This did not occur after injection of phosphate-buffered saline (PBS, control group). When the animals were subjected to subsequent kindling at either the hippocampus (HP) or the amygdala (AM), only the experimental group showed a significant facilitation of kindling rate. The results suggest that an NMDA receptor in the reuniens nucleus participates in modulation of temporal limbic excitability and seizure development.

Kindling of the massa intermedia of the thalamus in rats.

The kindling response of the massa intermedia (MI) was assessed in rats. Clinical manifestation of the MI kindling was generally similar to that of limbic kindling, and positive transfer to the amygdala (AM) was obtained following MI kindling. However, MI kindling showed (1) a relatively high after discharge threshold which sometimes increased during the course of kindling, (2) a seizure stage instability with frequent regression to earlier stages, (3) a failure to establish a generalized seizure triggering threshold with an 'all-or-none' property, and (4) a generalized tonic-clonic seizure, which was quite different from a kindled limbic seizure, during early phase of kindling. Furthermore, the MI stimulation caused violent beating movement of the forelimbs, jumping, or running regardless of presence/absence of afterdischarge. The findings suggest that mechanisms other than a simple activation of limbic structures are involved in the process of MI kindling.

Centrally induced feline emotional behavior and limbic kindling.

The threshold intensity required for electrical hypothalamic/mesencephalic stimulation to elicit emotional behavior in cats was examined chronologically during limbic kindling (n = 9/5), and without kindling (n = 3/3) for a matching control period. After the completion of primary site amygdaloid (AM) or hippocampal (HIPP) kindling, the hypothalamic defensive behavior threshold showed a +/- 20% fluctuation from the prekindling baseline with a mean tendency for reduction as in the control animals. The flight behavior threshold increased in the kindled animals, and decreased in the controls; however, the degree of change was not statistically significant. In contrast, the mesencephalic defensive behavior threshold, which was quite stable in the controls, decreased significantly upon primary (mean -13.5%) and secondary site (mean -22.2%) AM kindling, whereas the flight and screeching (sound emission) behavior threshold remained unchanged throughout kindling. The decreased or unchanged thresholds for each behavior were independent of the timing of the hypothalamic/mesencephalic stimulation after kindled generalized convulsion. The decreased mesencephalic defensive behavior threshold persisted during a 1- to 3-month rest period without kindling stimulation. These findings suggest that acquisition of feline AM-kindled seizure susceptibility is associated with a lasting facilitation of midbrain (but not hypothalamic) excitability for defensive (but not flight) behavior.

Clinical evaluation of total-body hyperthermia combined with anticancer chemotherapy for far-advanced miscellaneous cancer in Japan.

One hundred sixty-eight patients with miscellaneous far-advanced cancer received a total of 444 extracorporeally induced total-body hyperthermia (TBHT) treatments in seven Japanese hospitals. Overall, a regression of malignancy was observed in 39 of 132 evaluable patients (29.5%) and the most favorable results were obtained for patients with lung cancer. Irrespective of whether the tumors were primary or secondary lesions or recurrences, favorable results were obtained in patients whose tumors were in the lung, liver, lymph nodes, and soft tissue. No relationship was found between an objective response to TBHT and histologic types of the tumors. There was no clear relationship between an objective tumor response and the nature of the simultaneous chemotherapy during hyperthermia. Antitumor effects were not evaluable in 36 patients (21.4%). Of these 36 patients, 33 died before evaluation could be made; 24 died of various complications and 9 died of cachexia without complication. The mortality increased in proportion to the reduction of the performance status of patients before TBHT. These results indicate that TBHT should be used as therapy for patients whose tumors are in the lung, liver, lymph node, and soft tissue and then only on patients in generally good condition.

Facilitation of premotor cortical seizure development by intranigral muscimol.

The role of the substantia nigra in seizure development was investigated using a chronic model of partial onset generalized seizure induced by low frequency cortical stimulation. Unilateral intranigral micro-injection of muscimol, a GABA receptor agonist, was found to facilitate partial onset seizure development, but did not affect developed seizures. This finding suggested that a non-dopaminergic, presumably GABAergic, mechanism was involved since the facilitatory effect of intranigral muscimol was not modified by haloperidol pretreatment.

[Electrocardiographic and hemodynamic changes during systemic hyperthermia (42 degrees C)].

During systemic hyperthermia (42 degrees C), depression of ST segments or T wave changes in the left precordial leads were noticed in 56% of patients, and 29% of cases showed right bundle branch block. Supraventricular tachycardia was found in 26% and temporary deviation of mean frontal vector to the left axis was observed in 15%. These changes disappeared following recovery to normal temperature. The ECG findings for any particular patient were similar even during a second period of hyperthermia. Pulse rate became elevated by 1.7 times, and cardiac output became up to 2.4 times higher at 42 degrees C.

[Extracorporeal systemic hyperthermia and cis-diamminedichloroplatinum for treatment of patients with advanced cancer].

Extracorporeal systemic hyperthermia was effective in removing pleural effusion or ascites and for pain relief in patients with advanced cancer. The administration of cisplatin was combined with hyperthermia. Partial remission was noted in 18% of the cases. With the use of cisplatin dosage over 1 mg/kg, approximately 50% of cases showed effective results. Cisplatin dosage should be 1.6mg/kg or more when combined with hyperthermia. Renal failure was the most common complication.

Antiepileptic and prophylactic effects of tetrahydrocannabinols in amygdaloid kindled rats.

The antiepileptic and prophylactic effects of delta9-tetrahydrocannabinol (delta9-THC) and delta8-THC were examined in rats that developed generalized seizures in response to intermittent electrical stimulation of the amygdala (kindling). Both isomers of the THC were able to acutely suppress kindled seizures, but consistent antiepileptic effects were obtained only with high, toxic dosages. Tolerance to the antiepileptic effects of THC developed very rapidly when the drugs were give repeatedly, and there was evidence that the repeated administration of a high dosage of delta9-THC resulted in a state of acute physical dependence. Administration of the isomers of THC during seizure development resulted in a suppression of kindling, suggestive of a prophylactic effect. The rate of rekindling after withdrawal of the drugs was not significantly different from that of vehicle-treated control rats, however, indicating that a genuine prophylactic effect was not obtained.

Pharmacological prophylaxis in the kindling model of epilepsy.

Review of antiepileptic drug assessment to date by means of the kindling model of epilepsy suggests that it fills a gap that is evident in standard screening methods such as maximum electroshock or pentylenetetrazol screening tests. However, in order to obtain a comprehensive profile of antiepileptic drugs regarding prophylaxis of developing seizures and treatment of well-established seizures through the kindling preparation, it is desirable to have the following: (1) standardization of kindling techniques, (2) examination of drug effects on developing as opposed to developed seizures, (3) use of a variety of animal species, involving different functional brain sites, and (4) monitoring of plasma levels of the drug administered. It is envisaged that judicious use of the kindling preparation might also enable us to gain some insight into the mechanisms by which drugs produce their prophylactic or therapeutic effect.

Prophylactic effects of phenytoin, phenobarbital, and carbamazepine examined in kindling cat preparations.

Prophylactic effects of phenobarbital, phenytoin (diphenylhydantoin), and carbamazepine were examined in amygdaloid kindling preparations in cats. Daily electrical stimulation was delivered at the time of peak plasma levels. Comparative examination of the chronological pattern of the clinical seizure development, after discharge growth, and formation of distant independent spike foci was made between periods of kindling with chronic drug administration and of rekindling without drugs. Both phenobarbital and carbamazepine were effective, but phenytoin was totally ineffective. Prophylactic action of phenobarbital and carbamazepine was mainly through the suppression of the development of motor seizures manifestations in the former and the same with the development of sustained after discharge in the latter. The kindling preparation appears to possess many desirable features as an ideal model of human epilepsy for the purpose of assessment and recruitment of potential antiepileptic drugs and development of a rational pharmacotherapeutic approach for the management and prevention of seizure disorder.

Acute anticonvulsant effects of diphenylhydantoin, phenobarbital, and carbamazepine: a combined electroclinical and serum level study in amygdaloid kindled cats and baboons.

This preliminary study utilizing the kindling model of established epilepsy has provided information about the most effective routes of administration for diphenylhydantoin, phenobarbital, and carbamazepine in baboons and cats. The time of peak plasma levels for these drugs has been demonstrated in these animals so that experimental protocols can be designed to deliver the agents at appropriate times prior to the kindling stimulation. In addition, dose-effectiveness data is presented for these species. In 1 baboon, phenobarbital was also seen to suppress photosensitive seizures. The potential usefulness of the kindling model in anticonvulsant research is suggested.

Effects of tetrahydrocannabinols on kindled amygdaloid seizures and photogenic seizures in Senegalese baboons, Papio papio.

Intraperitoneal injections of delta 8-tetrahydrocannabinol (THC) and delta 9-THC failed to affect myoclonic response to photic stimulation in Senegalese baboons (Papio papio). However, both isomers of THC exerted dose-related antiepileptic effects upon established kindled convulsions provoked by electrical stimulation of amygdala in the same species. Delta 9-THC was more potent than delta 8-THC, in terms of both antiepileptic effects and general toxicity. The antiepileptic effects of the THC isomers appear to be due mainly to the suppression of propagation of the induced afterdischarge to distant cerebral structures, although high doses also seem to suppress afterdischarge at the site of stimulation.