Exploring the neuropharmacological potential of empagliflozin on nootropic and scopolamine-induced amnesic model of Alzheimer's like conditions in rats

BACKGROUND

Alzheimer's disease (AD) is one of the most challenging and prevalent neurodegenerative disorder globally with a rising prevalence, characterized by progressive cognitive decline, memory loss, and behavioural changes. Current research aims to determine the nootropic and anti-amnesic effect of Empagliflozin (EMPA) against scopolamine-induced amnesia in rats, by modulating the cholinergic and N-Methyl D-Aspartate (NMDA) receptors.

METHODS

Rats were treated once daily with an EMPA (5 and 10 mg/kg) and donepezil (2.5 mg/kg) for successive 26 days. During the final 13 days of treatment, a daily injection of scopolamine (1 mg/kg) was administered to induce cognitive deficits.

RESULTS

EMPA was found to be significantly reduce escape latency, increase time spent in the target quadrant, and enhanced the number of target zone crossings in the Morris water maze (MWM) test, indicating improved spatial memory. Moreover, EMPA increased the recognition index and the number of spontaneous alternations in the novel object recognition (NOR) and Y-maze tests, respectively, suggesting enhanced memory.

DISCUSSION

Interestingly doses of EMPA (5 mg/kg, 10 mg/kg) exhibited memory-enhancing effects even in the absence of scopolamine-induced impairment. Biochemical analysis revealed that EMPA elevated the levels of glutathione (GSH), a potent antioxidant, while decreasing lipid peroxidation (LPO) activity and increasing catalase (CAT) levels, indicating its antioxidative properties. Interestingly molecular docking studies revealed that EMPA fit perfectly in the active sites of M1 muscarinic acetylcholine (mACh) and NMDA receptors. These results indicated that the nootropic and antiamnesic effect of EMPA is possibly mediated via M1 and NMDA receptors and might be a remedy for AD.

In-silico studies of 2-aminothiazole derivatives as anticancer agents by QSAR, molecular docking, MD simulation and MM-GBSA approaches

Targeting Hec1/Nek2 is considered as crucial target for cancer treatment due to its significant role in cell proliferation. In pursuit of this, a series of twenty-five 2-aminothiazoles derivatives, along with their Hec1/Nek2 inhibitory activities were subjected to QSAR studies utilizing QSARINS software. The significant three descriptor QSAR model was generated, showing noteworthy statistical parameters: a correlation coefficient of cross validation leave one out (Q2LOO) = 0.7965, coefficient of determination (R2) = 0.8436, (R2ext) = 0.6308, cross validation leave many out (Q2LMO) = 0.7656, Concordance Correlation Coefficient (CCCCV = 0.8875), CCCtr = 0.9151, and CCCext = 0.0.7241. The descriptors integral to generated QSAR model include Moreau-Broto autocorrelation, which represents the spatial autocorrelation of a property along the molecular graph's topological structure (ATSC1i), Moran autocorrelation at lag 8, which is weighted by charges (MATS8c) and RPSA representing the total molecular surface area. It was noted that these descriptors significantly influence Hec1/Nek2 inhibitory activity of 2-aminothiazoles derivatives. New lead molecules were designed and predicted for their Hec1/Nek2 inhibitory activity based on the developed three descriptor model. Further, the ADMET and Molecular docking studies were carried out for these designed molecules. The three molecules were selected based on their docking score and further subjected for MD simulation studies. Post-MD MM-GBSA analysis were also performed to predicted the free binding energies of molecules. The study helped us to understand the key interactions between 2-aminothiazoles derivatives and Hec1/Nek2 protein that may be necessary to develop new lead molecules against cancer.Communicated by Ramaswamy H. Sarma.

Possible involvement of GABAergic system on central amygdala Mediated anxiolytic effect of agmatine in rats

OBJECTIVES

To study the pharmacological interactions between agmatine and gamma aminobutyric acid (GABA) modulatory agents in the regulation of anxiety-like behavior in rats.

MATERIALS AND METHODS

Male Wistar rats were treated drugs per se or in combination and 15 min after last injection were subjected to elevated plus-maze (EPM) test. Anxiety-like behavior was evaluated by measuring behavioral conventional readout, open arm activity (duration and/or entries) for 5-minute duration.

RESULTS

Acute intra-central amygdala (CeA) injection of agmatine (0.1-0.6 μmol/site/rat), muscimol (0.25-1 nmol/site/rat), diazepam (5-20 μg/site/rat) and allopregnanolone (2-8 μg/site/rat) increased open arm entries of the rats in EPM suggesting anxiolytic effect in dose dependent manner. Moreover, the anxiolytic effect at subeffective dose of agmatine (0.1 μmol/site/rat) was potentiated by subeffective dose of muscimol (0.25 nmol/site/rat), diazepam (5 μg/site/rat) and allopregnanolone (4 μg/site/rat). Whereas, pretreatment with GABAA receptor antagonist, bicuculline (10 ng/site/rat) blocked the anxiolytic effect of agmatine and its synergistic effect of agmatine plus muscimol. Similarly, benzodiazepine (BZD) receptor antagonist, flumazenil (15 μg/site/rat) and GABA allosteric modulator antagonist, RO 15-45 13 (10 μg/site/rat) reduced the anxiolytic effect of agmatine, given alone and with diazepam and allopregnanolone, respectively.

CONCLUSION

These results indicated that anxiolytic effect of agmatine is medicated via GABAergic mechanisms, probably conciliated by the GABAA receptor subtypes. Modulation of interplay between agmatine and GABAA receptor activity might be a pertinent solution for the regulation of anxiety.

Development and Characterization of Pentaerythritol-EudragitRS100 Co-processed Excipients as Solid Dispersion Carriers for Enhanced Aqueous Solubility, In Vitro Dissolution, and Ex Vivo Permeation of Atorvastatin

Atorvastatin (ATV), a lipid-lowering agent, has low oral bioavailability due to its poor water solubility, permeability, and low dissolution rate. Therefore, pentaerythritol-EudragitRS100 co-processed excipients (PECE) were synthesized, and their feasibility as solid dispersion carriers (ATV-PECE-SD) for improving the solubility, permeability, and dissolution rate of ATV was explored. Solid dispersions were assessed in terms of particle size and zeta potential, and solubility, in vitro dissolution, and ex vivo permeation studies were studied. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD) were used as characterization tools. ATV-PECE-SD3 (1:4) formulations exhibited a small particle size with high stability. Physicochemical evaluation evidenced the formation of solid dispersion due to the involvement of weak electrostatic interaction between the polar functional groups of ATV and PECE carriers. ATV-PECE-SD3 (1:4) significantly enhanced the water solubility by ∼43-fold compared to pure ATV. In vitro dissolution studies showed that optimized formulation enhanced the dissolution rate of ATV compared to pure ATV. Ex vivo permeation results revealed that ATV-PECE-SD3 (1:4) enhanced the permeation rate of ATV compared to pure ATV. The optimized formulations significantly improved the dissolution rate of ATV in the fed state due to the food effect and micelle formation mechanism compared to the fasted state. The study concludes that co-processed excipients could be used as promising solid dispersion carriers to enhance the aqueous solubility, permeability, and dissolution rate of ATV.

Explorations of novel pyridine-pyrimidine hybrid phosphonate derivatives as aurora kinase inhibitors

For developing novel therapeutic agents with good anticancer activities, a series of novel pyridine-pyrimidine hybrid phosphonate derivatives4(a-q) were synthesized by the Kabachnik-Fields method using CAN as catalyst. The compound 4o exhibited the most potent anticancer activity with an IC₅₀ value of 13.62 μM, 17.49 μM, 5.81 μM, 1.59 μM and 2.11 μM against selected cancer cell lines A549, Hep-G2, HeLa, MCF-7, and HL-60, respectively. Compound 4o displayed seven times more selectivity towards Hep-G2 cancer cell lines compared to the human normal hepatocyte cell line LO2 (IC₅₀ value 95.33 μM). Structure-Activity Relationship (SAR) studies were conducted on the variation in the aromatic ring (five-membered heterocyclic ring, six-membered heterocyclic ring) and the variation of substituents on the phenyl ring (electron donating groups, electron withdrawing groups). Furthermore, the mechanism of anticancer activity was clarified by further explorations in bioactivity by using in vitro aurora kinase inhibitory activity and molecular docking studies. The results showed that the compound 4o at IC₅₀concentrationdemonstrated distinctive morphological changes such as cell detachment, cell wall deformation, cell shrinkage and reduced number of viable cells in cancer cell lines. Compound 4o induced early apoptosis and late apoptosis of 27.7% and 6.1% respectively.

Calcium Ion-Sodium Alginate-Piperine-Based Microspheres: Evidence of Enhanced Encapsulation Efficiency, Bio-Adhesion, Controlled Delivery, and Oral Bioavailability of Isoniazid

Isoniazid (INH) is a first-line chemotherapeutic drug employed in the management of tuberculosis. However, its extensive first-pass metabolism, short-life life, and low oral bioavailability confined its medical application. Therefore, the calcium ion-alginate-piperine microspheres (INH-CaSP Ms) was prepared to enhance encapsulation efficiency, controlled delivery, and oral bioavailability of INH. The INH-CaSP Ms was developed using a modified emulsification method and optimized via Box-Behnken design (BBD). Optimized INH-CaSP Ms were characterized for encapsulation efficiency, differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR), bio-adhesion, in vitro dissolution, ex vivo permeation, and oral bioavailability studies. Characterization studies confirmed the formation of microspheres. The INH-CaSP Ms showed spherical microspheres with enhanced encapsulation efficiency (~ 93.03 ± 1.54% w/w). The optimized INH-CaSP Ms exhibited higher bio-adhesion around (~ 81.41 ± 1.31%). The INH-CaSP Ms enhanced the dissolution rate of INH (~ 57%) compared to pure INH (~ 57%) and INH-SA Ms (~ 81%) in simulated gastric fluid (SGF, pH 1.2) and simulated intestinal fluid (SIF, pH 7.4). The same formulations improved the permeation rate of INH (~ 90%) compared to pure INH (~ 55%) and INH-SA Ms (~ 80%). The oral bioavailability results indicated that INH-CaSP Ms appreciably improved the oral bioavailability of INH via increasing the Cmax, Tmax, t_1/2, and AUC parameters compared to pure INH. The study demonstrates that the development of INH-CaSP Ms via cross-linked coordinate bond interaction between divalent cation calcium ion-alginate complex and anion piperine bio-enhancer is an effective approach for enhancing the encapsulation efficiency, bio-adhesion, controlled release, and oral bioavailability of INH.

Antimutagenic Activity of Cassia Auriculata Linn Fractions along with Anticancer Activity in Male Albino Mice

Background: In recent years, there has been a surge in interest in studying plant-derived materials and their impact on DNA. Herbal products include a number of natural substances that may help protect cells against mutagen-induced cell damage. Aim: The purpose of this research was to assess the genotoxic effects of Cassia Auriculata Linn flavonoids (CAF) and Cassia Auriculata Linn saponin (CAS) rich fractions on mouse bone marrow cells utilizing chromosomal aberration test and micronucleus assay. Methodology: The suppressive impact of CAF and CAS on 7, 12-dimethylbenz (α) anthracene (DMBA) and Croton oil induced skin tumor promotion in mice with topical administration twice weekly for 18 weeks is also investigated in this work. Three dosages of 100 and 200 mg/kg body weight were used. Single oral dosages of CAF and CAS Fraction at the three levels did not enhance the number of micronucleate polychromatic erythrocytes in the micronucleus experiment. Result: In mice bone marrow cells, a single oral treatment of CAF and CAS fraction revealed no significant alterations in mitotic indices or chromosomal aberration induction. The clastogenicity of CYP was considerably decreased by pretreatment with CAF and CAS fraction. As a result, it can be stated that CAF and CAS fraction had no genotoxic impact on mouse bone marrow cells. Conclusions: The portions of Cassia Auriculata have been shown to be non-genotoxic and non-clastogenic at the quantities utilized in this investigation. CAF and CAS Fraction might possibly be a promising skin tumor promotion reducing agent, according to this research.

Egg White Protein Carrier-Assisted Development of Solid Dispersion for Improved Aqueous Solubility and Permeability of Poorly Water Soluble Hydrochlorothiazide

Hydrochlorothiazide (HTZ) is a first-line drug used in the treatment of hypertension suffered from low oral bioavailability due to poor aqueous solubility and permeability. Hence, lyophilized egg white protein-based solid dispersion (HTZ-EWP SD) was developed to explore its feasibility as a solid dispersion carrier for enhanced aqueous solubility and permeability of HTZ. The HTZ-EWP SD was prepared using the kneading method. HTZ-EWP SD was characterized using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier transforms infrared spectroscopy (FT-IR), powder X-ray diffractometer (PXRD), solubility, in vitro dissolution, and ex vivo permeation studies. The physico-chemical evaluation suggested the formation of the solid dispersion. Optimized HTZ-EWP SD4 drastically enhanced (~32-fold) aqueous solubility (~16.12 ± 0.08 mg/mL) over to pure HTZ (~ 0.51 ± 0.03 mg/mL). The dissolution study in phosphate buffer media (pH 6.8) revealed that HTZ-EWP SD4 significantly enhanced the release rate of HTZ (~ 87 %) over to HTZ (~ 25 %). The permeation rate of HTZ from optimized HTZ-EWP SD4 was enhanced significantly (~ 84 %) compared to pure HTZ (~ 24 %). Optimized HTZ-EWP-SD4 enhanced the rate of HTZ dissolution (~ 86 %) in FeSSIF (fed state simulated intestinal fluid), compared to a low dissolution rate (~ 72 %) in FaSSIF (fasted state simulated intestinal fluid) state after 2-h study. Obtained results conclude that lyophilized egg white protein can be utilized as an alternative solid dispersion carrier for enhancing the solubility and permeability of HTZ.

Design, fabrication, and characterization of graft co-polymer assisted ocular insert: a state of art in reducing post-operative pain

PURPOSE

Targeted delivery of drugs at appropriate concentrations to ocular tissues is required to avoid wastage. Hence, advanced systems that maximize the release of poorly soluble drugs and deliver them at ocular sites must be designed.

METHODS

In this study, Soluplus^® (polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol-graft copolymer) was selected as a solubilizer as well as film former for preparing ocular inserts and polyethylene glycol 400 (PEG-400) as a plasticizer. On the basis of an initial phase solubility study, the maximum concentration of Soluplus^® possible was used for developing the inserts. An optimized formulation was obtained using a 3²-factorial design. Two factors at three levels were used to design the ocular inserts. Soluplus^® (X ₁) and the plasticizer, PEG-400 (X ₂), were set as the independent variables at various levels, and the Rel_4h (drug release in 4 h, Y ₁) and tensile strength (Y ₂) were set as the dependent variables. A pre-formulation study was conducted to select suitable materials.

RESULTS

Various physico-chemical parameters of the optimized formulation, including the tensile strength and folding endurance, were studied using FT-IR, DSC, XRD, and SEM. An in vitro dissolution study was conducted to determine the amount of drug released. There was no redness, swelling, or watering of the rabbit eye.

CONCLUSION

It was concluded that the ocular inserts of the poorly soluble nepafenac developed using a graft-co-polymer enhanced the solubility and utilization of the drug for a prolonged period.

LC-ESI-MS analysis of taxoids from the bark of Taxus wallichiana

LC-ESI-MS analysis was carried out for taxoid profiling of partially purified methanol extracts of the stem bark of Taxus wallichiana growing in different regions of the Himalayas (Kashmir, Himachal Pradesh, UP hills, Sikkim and Arunachal Pradesh). Cone voltage fragmentation of the protonated, ammonium or sodium cationized molecular species resulted in diagnostic fragment ions. Thus, information about the number and nature of substituents and the taxane skeleton (whether it is normal or rearranged) was readily available from the LC-ESI-MS spectra. The rearranged 11(15-->1)-abeo-taxanes showed a characteristic elimination of the hydroxyisopropyl along with an acetoxy group. The identification of the taxoids was achieved by comparison of the ESI mass spectra with those of the authentic taxoids available to us or by interpreting the ESI mass spectra. The results were also corroborated by MS/MS analysis of the partially purified extract injected directly into the ESI source. Paclitaxel, its analogues and their xylosides are present in samples from all the regions. An interesting observation is the detection of a large number of basic taxoids having nitrogen-containing side chains.

Vertebral artery stenting

The safety and efficacy of endoluminal stenting in treating atherosclerotic vertebral artery disease was evaluated in 38 vessels in 32 patients. Indications for revascularization included diplopia (n = 4), blurred vision (n = 4), dizziness (n = 23), transient ischemic attacks (n = 4), drop attack (n = 1), gait disturbance (n = 1), headache (n = 2), and asymptomatic critical stenosis (n = 1). Success (< 20% residual diameter stenosis, without stroke or death) was achieved in all 32 patients (100%). One patient experienced a transient ischemic attack (TIA) 1 hr after the procedure. At follow-up (mean, 10.6 months), all patients (100%) were alive and 31/32 (97%) were asymptomatic. One patient (3%) had in-stent restenosis at 3.5 months and underwent successful balloon angioplasty. Endoluminal stenting of vertebral artery lesions is safe, effective, and durable as evidenced by the low recurrence rate. Primary stent placement is an attractive option for atherosclerotic vertebral artery stenotic lesions. Cathet Cardiovasc Intervent 2001;54:1-5.

Antidepressant-like effect of the neurosteroid 3alpha-hydroxy-5alpha-pregnan-20-one in mice forced swim test

The present study aimed to examine the antidepressant-like effect of the neurosteroid 3alpha-hydroxy-5alpha-pregnan-20-one (3alpha, 5alpha THP) using the forced swim test in mice. Intracerebroventricular (ICV, 1 or 2 microg/mouse) or intraperitoneal (IP, 0.5, 1, or 2 mg/kg) administration of 3alpha, 5alpha THP dose-dependently reduced the duration of immobility in forced swim test without accompanying changes in ambulatory or rearing behaviors in the open-field test. The antidepressant-like effect of 3alpha, 5alpha THP (1 microg/mouse, ICV) was potentiated by prior administration of the GABA(A) receptor agonist, muscimol (0. 5 mg/kg, IP) and blocked by prior administration of GABA(A) receptor antagonist, bicuculline (1 mg/kg, IP). Administration of the agonist at diazepam binding inhibitor receptors, 4'-chlorodiazepam (4'CD, 15 mg/kg, IP) or N,N-di-n-hexyl-2-(4-fluorophenyl)-indol-3-acetamide (FGIN 1-27, 1 or 2 microg/mouse, ICV), the 11beta-hydroxylase inhibitor, metyrapone (150 mg/kg, IP and 1 or 2 microg/mouse, ICV) and the selective serotonin reuptake inhibitor (SSRI), fluoxetine (20 mg/kg, IP), which are known to increase the endogenous level of neurosteroids, also reduced the duration of immobility in forced swim test. The tricyclic antidepressant, imipramine (20 mg/kg, IP), which does not increase the 3alpha, 5alpha THP in the brain, also reduced the immobility time. While the antidepressant-like effect of fluoxetine, which is known to selectively increase the brain content of 3alpha, 5alpha THP, was either blocked partially by bicuculline (1 mg/kg, IP) or potentiated by muscimol (0.5 mg/kg, IP), the antidepressant-like effect of imipramine was not modified by bicuculline. These results demonstrate the antidepressant-like effect of the neurosteroid 3alpha, 5alpha THP, and suggest further evaluation for its development as a new class of antidepressant drug.

Analysis of taxol and major taxoids in Himalayan yew, Taxus wallichiana

A reversed-phase column liquid chromatography method for the analysis of taxol, 10-deacetylbaccatin III, baccatin IV, 1-hydroxybaccatin I, 2-acetoxybrevifoliol, brevifoliol, 2'-deacetoxydecinnamoyltaxinine J and 2'-deacetoxytaxinine J in yew needles has been developed using a Nova-Pak Phenyl column and a binary gradient profile. The various aspects of analysis such as extraction efficiency, detection limits, reproducibility and peak purity were validated using UV-Vis as well as photodiode array detection.

Primary stenting in acute myocardial infarction: influence of diabetes mellitus in angiographic results and clinical outcome

BACKGROUND

The outcome of patients with diabetes after myocardial infarction (MI) has traditionally been worse than in their nondiabetic counterparts before and during the thrombolytic therapy era. Whether the fate of patients with diabetes might improve with mechanical intervention, particularly with primary stenting, has not previously been studied.

METHODS

We compared the angiographic and clinical outcome of 76 nondiabetic patients (aged 61 +/- 14 years; 66% male) and 28 patients with diabetes (aged 65 +/- 12 years; 64% male) consecutively treated with primary stenting for acute MI. Coronary Thrombolysis In Myocardial Infarction grade 3 flow was restored in 96% of diabetic and 97% of nondiabetic patients.

RESULTS

Angiographic results after stent deployment were similar in the 2 groups. At 1-month follow-up, all patients in both groups were alive. Patients with diabetes had a much higher incidence of stent thrombosis (18% vs 1%; P =.003), which accounted for the majority of the major cardiac events at 1 month (21% vs 4%; P =.009). At a mean follow-up of 315 +/- 13 days, 99% of nondiabetic and 89% of patients with diabetes were alive (P =.04). Overall freedom from a major cardiac event (death, MI, target vessel revascularization) at 315 +/- 13 day follow-up was 88% for nondiabetics and 54% for patients with diabetes (P =.0003). By multivariate analysis, diabetes mellitus was the most important predictor for development of 1-month (RR 9.89; 95% confidence interval, 1.6-30) and late major cardiovascular events (RR 8.39; 95% confidence interval, 2.93-24).

CONCLUSIONS

Primary stenting in acute MI is highly effective in restoring immediate TIMI 3 coronary flow in nondiabetic patients and patients with diabetes. This procedure may improve benefit in terms of mortality rate to both groups, particularly in patients with diabetes, compared with previous reports with thrombolytic therapy. Nevertheless, stent thrombosis and major cardiovascular events at 1 month and late follow-up are more frequent in patients with diabetes.

Predictors of stent thrombosis after primary stenting for acute myocardial infarction

The aim of the study was to determine if a hypercoagulable state that may persist for several months after an acute myocardial infarction may contribute to an increased incidence of stent thrombosis. Primary stenting was performed in 104 consecutive patients with acute myocardial infarction using 147 coronary stents. Twenty-eight patients (27%) were diabetic and 55 patients (53%) were smokers. A single stent was placed in 63%, two stents in 33%, and more than two stents in 4% of the patients. Procedural success was obtained in 97% of the patients. All stents were deployed using high-pressure balloon inflation. The reference vessel diameter and minimal lumen diameter after stent deployment were 3.30 +/- 0.42 and 3.23 +/- 0.42 mm, respectively. Six patients (5.7%) developed stent thrombosis within 1 month after the procedure complicated by reinfarction in five of the six patients. At 1-month follow-up, all patients remained alive. On multivariate analysis, independent predictors of stent thrombosis were diabetes mellitus (relative risk [RR] 5.2; 95% confidence interval [CI] 1.8, 25.1), tobacco use (RR 4.5; 95% CI 1.3, 24.5), number of stents: 1 vs. > 1 (RR 3.7; 95% CI 1.1, 15.9), minimal lumen diameter poststent placement (RR 0.03; 95% CI 0.0002, 0.74), and duration of chest pain before intervention (RR 1.1; 95% CI 1.01, 1.25). Stent thrombosis had not been associated with diabetes mellitus and tobacco use previously but is in agreement with the enhanced platelet aggregability, coagulation factor abnormalities, and impaired fibrinolysis characteristic of these patients.

Coronary stenting in cardiac allograft vasculopathy

OBJECTIVE

The purpose of this study was to evaluate acute angiographic success, in-hospital complications and long-term outcome after intracoronary stenting in patients with cardiac allograft vasculopathy.

BACKGROUND

The application of conventional interventional modalities to treat discrete lesions in patients with cardiac allograft vasculopathy is associated with higher procedural morbidity, mortality and higher restenosis compared to atherosclerotic coronary artery disease. Elective coronary stenting has been shown to lower restenosis rates and improve long-term outcome in selected patients with native coronary artery disease; however, its safety and efficacy in reducing restenosis in patients with cardiac allograft vasculopathy is unknown.

METHODS

Ten patients with 19 discrete lesions in a major coronary artery without diffuse distal disease underwent intracoronary stenting using Palmaz-Schatz stents. The average stent size was 3.4 mm, and the stent/artery ratio was 0.99+/-0.07. Eight of ten (80%) patients received antiplatelet therapy (aspirin plus ticlopidine) only.

RESULTS

Procedural success was 100% with no in-hospital stent thrombosis, Q-wave myocardial infarction or death. Minimal luminal diameter increased from 0.83+/-0.38 mm to 3.23+/-0.49 mm after stenting. Diameter stenosis decreased from 74.91+/-11.52% to 5.90+/-4.09% after stenting. Follow-up angiography was performed in 8 of 10 (80%) patients and 16 of 19 (84%) lesions. Target lesion revascularization was required in 2 of 10 (20%) patients and 3 of 16 (19%) lesions. Allograft survival was 7 of 10 (70%) at the end of 22+/-11 months follow-up.

CONCLUSIONS

Intracoronary stenting can be performed safely with excellent angiographic success in selected patients with cardiac allograft vasculopathy. The restenosis rate appears to be low despite the aggressive nature of the disease. A multicenter study with a larger number of patients is required to assess its efficacy in reducing restenosis and improving allograft survival.

Comparison of balloon angioplasty versus debulking devices versus stenting in right coronary ostial lesions

Angioplasty of aorto-ostial stenosis is associated with lower procedural success and a higher complication rate. The aim of the present study was to compare the acute and long-term results of balloon and new device angioplasty in 110 consecutive patients with right coronary ostial lesions. Patients were divided into 3 groups according to the angioplasty device used: group I (balloon only, n = 26), group II (debulking devices including excimer laser, directional and rotational atherectomy, n = 26), group III (stent, n = 58). Procedural success was highest in group III (96%) followed by group I (88%), and group II (77%). In-hospital complications were similar among the groups (p = NS). Patients in group III achieved the highest acute gain (2.61 mm) followed by groups II (1.92 mm), and I (1.39 mm, p <0.05). During follow up, target lesion revascularization and/or bypass surgery was required in 24% of patients in group III compared with 47% and 40% in groups I and II, respectively (p <0.05). Cardiac-event free survival was highest in the stent group (74%, p <0.005) and was similar between the balloon (39%) and debulking device groups (45%). Thus, among the currently available technologies, stenting of right coronary ostial lesions appears to provide excellent angiographic and long-term results.

Heterogeneity of cardiac allograft vasculopathy: clinical insights from coronary angioscopy

OBJECTIVES

With this study, we sought to examine the heterogeneity of cardiac allograft vasculopathy in vivo using coronary angioscopy as an adjunct to intravascular ultrasound, and we evaluated the clinical relations of immunologic and nonimmunologic risk factors with the different forms of cardiac allograft vasculopathy detected angioscopically.

BACKGROUND

Intravascular ultrasound detects vascular intimal proliferation accurately but is limited in its ability to delineate morphologic characteristics. Coronary angioscopy can evaluate intimal surface morphology by direct visualization and can differentiate pathologically distinct forms of plaque topography on the basis of color and contour.

METHODS

We studied 107 consecutive heart transplant recipients with intravascular ultrasound and angioscopy at the time of their annual angiogram, and we assessed the relation of nonimmunologic and immunologic risk factors to the development of cardiac allograft vasculopathy distinguished angioscopically into a pigmented (yellow) or nonpigmented (white) intimal thickening. We further evaluated the clinical differences in cardiac events among these two forms of angioscopically heterogeneous forms of cardiac allograft vasculopathy.

RESULTS

Significant clinical predictors of nonpigmented intimal thickening were advanced donor age and lower mean cyclosporine levels, whereas hyperlipidemia, cumulative prednisone dose and time since transplantation correlated with pigmented intimal hyperplasia. In addition, comparisons between the two angioscopic groups revealed increased intimal thickening, serum cholesterol, low density lipoprotein cholesterol, acute allograft rejection and time since transplantation in the group with pigmented intimal thickening (p < 0.05). With regard to cardiac events, nonpigmented plaque was more frequently found in the sudden death group (53% vs. 20%, p = 0.05), whereas the nonsudden cardiac event group had a significantly higher prevalence of pigmented plaque (80% vs. 47%, p = 0.07).

CONCLUSIONS

These findings indicate that cardiac allograft vasculopathy is a heterogeneous disease with varied morphologic expressions with different clinical implications. Furthermore, this investigation provides insight into the cohesive, yet diverse influences of various factors, particularly immunosuppression, in these forms of cardiac allograft vasculopathy.

Results of elective stenting of branch-ostial lesions

Coronary stenting using both Palmaz-Schatz and Gianturco-Roubin stents for branch ostial lesions was performed in 48 patients with high success and low complication rates. The 6-month event-free survival rates were high in these patients.

Comparison of aspirin alone versus aspirin plus ticlopidine after coronary artery stenting

This prospective nonrandomized study was performed comparing aspirin alone (n = 46) versus aspirin and ticlopidine (p = 338) following native coronary artery stenting. There were significantly more stent thrombosis events in the aspirin-only group than in the aspirin and ticlopidine group (6.5% vs 0.9%, p = 0.02) and significantly more Q-wave myocardial infarctions and cardiac-related deaths in the aspirin-only group than in the aspirin and ticlopidine group (6.5% vs 0%, p = 0.002 and 4.4% vs 0.3% p = 0.02, respectively).

Closure of an iatrogenic femoral artery pseudoaneurysm by transcutaneous coil embolization

Pseudo-aneurysm following diagnostic or interventional procedures is a well-recognized complication. Ultrasound guided compression repair is routinely used to close an uncomplicated pseudo-aneurysm. We describe a patient with a femoral artery pseudo-aneurysm following iliac angioplasty and stenting in which ultrasound guided compression repair failed. Pseudoaneurysm was successfully closed by transcutaneous coil embolization technique.

Utilization of the coronary balloon-expandable coil stent without anticoagulation or intravascular ultrasound

BACKGROUND

The balloon-expandable coil stent has been proved effective in the management of acute and threatened closure after coronary balloon angioplasty and has been shown to reduce restenosis in patients with suboptimal results after coronary balloon angioplasty. Coronary artery stenting has been limited by the occurrence of stent thrombosis and comorbidity related to anticoagulation. This study was undertaken to determine whether anticoagulation may be removed from poststenting protocols, thus reducing comorbidity without increasing stent thrombosis.

METHODS AND RESULTS

Between September 1994 and May 1995, 369 patients received balloon-expandable coil stents in native coronary arteries at our institution. Of these patients, 216 were selected for a protocol of aspirin and ticlopidine (for 1 month) without anticoagulation. Eligibility for this protocol followed satisfaction of certain procedural and angiographic criteria. These criteria included adequate coverage of intimal dissections, absence of residual filling defects, and normal (TIMI grade 3) flow in the stented vessel after high-pressure balloon inflations. Intravascular ultrasound was not used to guide stent deployment. The stenting procedure was planned in 37% of patients and unplanned in 63% of patients, including 25 (12%) for acute or threatened closure. During the 30-day follow-up period, stent thrombosis occurred in 2 patients (0.9%), there was 1 death (0.5%), and 2 patients (0.9%) underwent coronary bypass surgery. Vascular access-site complications occurred in 4 patients (1.9%), and bleeding that required blood transfusion occurred in 4 patients (1.9%).

CONCLUSIONS

Patients who receive the coronary balloon-expandable coil stent with optimal angiographic results without intravascular ultrasound guidance can be managed safely with a combination of aspirin and ticlopidine without anticoagulation.

Intravascular ultrasound-guided transluminal extraction atherectomy for restenosis after Gianturco-Roubin coronary stent implantation

Two patients with restenosis following implantation of the Gianturco-Roubin stent were successfully treated with the transluminal extraction atherectomy device, with the assistance of intravascular ultrasound guidance and adjunctive balloon angioplasty. The optimal management strategy of in-stent restenosis remains unclear, but the transluminal extraction atherectomy device may be an option for the management of restenosis within the Gianturco-Roubin stent.

Coronary thrombi increase PTCA risk. Angioscopy as a clinical tool

BACKGROUND

The presence of angiographically identified intracoronary thrombus has been variably associated with complications after coronary angioplasty. Angiography has been shown to be less sensitive than angioscopy for detecting subtle details of intracoronary morphology, such as intracoronary thrombi. The clinical importance of thrombi detectable by angioscopy but not by angiography is not known.

METHODS AND RESULTS

Percutaneous coronary angioscopy was performed in 122 patients undergoing conventional coronary balloon angioplasty (PTCA) at six medical centers. Unstable angina was present in 95 patients (78%) and stable angina in 27 (22%). Therapy was not guided by angioscopic findings, and no patient received thrombolytic therapy as an adjunct to angioplasty. Coronary thrombi were identified in 74 target lesions (61%) by angioscopy versus only 24 (20%) by angiography. A major in-hospital complication (death, myocardial infarction, or emergency bypass surgery) occurred in 10 of 74 patients (14%) with angioscopic intracoronary thrombus, compared with only 1 of 48 patients (2%) without thrombi (P = .03). In-hospital recurrent ischemia (recurrent angina, repeat PTCA, or abrupt occlusion) occurred in 19 of 74 patients (26%) with angioscopic intracoronary thrombi versus only 5 of 48 (10%) without thrombi (P = .03). Relative risk analysis demonstrated that angioscopic thrombus was strongly associated with adverse outcomes (either a major complication or a recurrent ischemic event) after PTCA (relative risk, 3.11; 95% CI, 1.28 to 7.60; P = .01) and that angiographic thrombi were not associated with these complications (relative risk, 0.85; 95% CI, 0.36 to 2.00; P = .91).

CONCLUSIONS

The presence of intracoronary thrombus associated with coronary stenoses is significantly underestimated by angiography. Angioscopic intracoronary thrombi, the majority of which were not detected by angiography, are associated with an increased incidence of adverse outcomes after coronary angioplasty.

Coronary angioscopy of abrupt occlusion after angioplasty

OBJECTIVES

This study used angioscopy to determine the specific cause of vessel occlusion after percutaneous transluminal coronary angioplasty and compared the angiographic and angioscopic lesion morphologies in this setting.

BACKGROUND

Occlusion of a dilated coronary artery is the major cause of morbidity and mortality after coronary angioplasty. Attempts to reopen occluded vessels are either empirically guided or directed by angiography, which has inherent limitations. Angioscopy, the in vivo direct visualization of the endovascular surface, is potentially a more accurate means of identifying the cause of vessel occlusion after angioplasty.

METHODS

Percutaneous coronary angioscopy was performed in 17 patients (17 vessels) after angiographic confirmation of postangioplasty vessel occlusion.

RESULTS

Angioscopy demonstrated the primary cause of the postangioplasty occlusion to be dissection in 14 patients (82%) and intracoronary thrombi in 3 (18%). Compared with angioscopy, angiography was significantly less accurate in identifying the specific cause of the occlusion and correctly identified the cause of vessel occlusion in only 5 (29%) of 17 patients (p < 0.001), including 4 (29%) of 14 deep dissections and 1 (33%) of 3 occlusive thrombi.

CONCLUSIONS

Angioscopy specifically identified the cause of occlusion in every patient, with coronary dissection the predominant cause of abrupt occlusion after coronary angioplasty. However, angiography was unable to identify a specific cause for vessel occlusion in the majority of our patients. Angioscopy may therefore prove useful in selecting specific treatment strategies for patients with abrupt occlusion after angioplasty, such as stent placement, atherectomy, repeat dilation or thrombolysis.

Cardiac allograft vasculopathy assessed by intravascular ultrasonography and nonimmunologic risk factors

The genesis of cardiac allograft vasculopathy has been linked to nonimmunologic endothelial injury. Studies evaluating the role of nonimmunologic risk factors have thus far been limited to angiographic assessment. Intravascular ultrasound can detect cardiac allograft vasculopathy before it becomes angiographically evident. To assess the influence of nonimmunologic risk factors in the development of cardiac allograft vasculopathy, we studied 101 consecutive cardiac transplant recipients who underwent intracoronary ultrasound imaging during routine, annual coronary angiography. Based on the severity of intimal thickening, patients were divided into 2 groups: group 1 = minimal, mild, or moderate intimal thickness; and group 2 = severe intimal thickness. Cardiac transplant recipients with severe intimal thickness had higher levels of total cholesterol (267 +/- 70 vs 227 +/- 41 mg/dl, p = 0.0008), low-density lipoprotein cholesterol (187 +/- 47 vs 139 +/- 31 mg/dl, p = 0.0001), and triglycerides (237 +/- 75 vs 182 +/- 88 mg/dl, p = 0.0004), a higher percentage of weight gain (12 +/- 4% vs 8 +/- 5%, p = 0.0001), a larger body mass index (30 +/- 4 vs 25 +/- 3, p = 0.0001), and older donor age (27 +/- 5 vs 23 +/- 7 years, p = 0.005) than recipients with mild or moderate intimal thickness. Multiple regression analysis established that total cholesterol, low-density lipoprotein cholesterol, triglyceride levels, obesity indexes, donor age, and years following cardiac transplantation (p < 0.01) were independent predictors of the severity of intimal thickening, and thus the severity of cardiac allograft vasculopathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Predictors of restenosis: a morphometric and quantitative evaluation by intravascular ultrasound

Despite advances in catheter-based interventional techniques, restenosis remains a major complication of angioplasty. Recently, intravascular ultrasound imaging (IVUS) has provided new insight into plaque composition and geometric distribution inside the vessel. To investigate if IVUS-defined parameters can predict restenosis in patients after coronary angioplasty, we performed IVUS in 33 patients (33 lesions) after balloon angioplasty (n = 25) or directional atherectomy (n = 8). Qualitative analysis included assessment of plaque composition, plaque eccentricity, plaque fracture, and presence of dissection. In addition, minimal luminal diameter, percent diameter stenosis, percent area stenosis, plaque burden, and elastic recoil were quantitatively analyzed. Follow-up data were obtained 1, 2, and 6 months after angioplasty and were available for 30 patients. Angiographic restenosis occurred in 11 patients (group 1), and no restenosis occurred in 19 patients (group 2) by clinical (n = 10) or angiographic (n = 9) assessment. Plaque fracture was noted in 30% of group 1 patients and 74% of group 2 patients (p = 0.04). Major dissections were more frequent in group I than in group II (78% vs 10%, p = 0.009). Of the quantitative parameters analyzed, plaque burden was significantly higher in group 1 than in group 2 (0.50 +/- 0.05 vs 0.34 +/- 0.05, p = 0.0001). In 78% of the patients with plaque burden of > 0.40, restenosis developed. Thus, of the various parameters analyzed, the absence of plaque fracture, the existence of a major dissection, and greater plaque burden were associated with increased incidence of restenosis. Our results indicate that IVUS can identify a subset of patients in whom restenosis is likely to develop. Information about the morphologic features of the atheroma and its composition may be used to modify the interventional strategy and thus optimize lumen size and possibly reduce the chance of restenosis.

Placement of "biliary" stents in saphenous vein coronary bypass grafts

Angioplasty of coronary saphenous vein grafts has been associated with less favorable results than in native coronary arteries owing to a higher acute complication rate and an increased incidence of restenosis. We placed 16 nonarticulated balloon expandable stainless steel "biliary" stents at the sites of 13 stenotic or occluded aortocoronary saphenous vein graft lesions in 11 patients. All of the lesions were stented successfully. There were no instances of stent thrombosis or stent embolism. The percent diameter stenosis was reduced from 85.5 +/- 14.1% to 3.5 +/- 4.4% (p < .001), and the minimal lumen diameter of the lesion increased from 0.7 +/- 0.7 mm at baseline to 3.7 +/- 0.2 mm (p < .001) after stent placement. We conclude that this noncoronary stent appears to be safe and effective for treating saphenous vein coronary bypass grafts. The high procedural success rate and excellent angiographic results are very encouraging, while the restenosis rates remain to be determined.

Assessment of intracoronary morphology in cardiac transplant recipients by angioscopy and intravascular ultrasound

Percutaneous coronary angioscopy and intravascular ultrasound are sensitive intravascular imaging methods for detecting early changes in coronary morphology in cardiac transplant recipients. To compare the 2 imaging modalities, 29 consecutive cardiac transplant recipients underwent percutaneous coronary angioscopy and intravascular ultrasound during annual coronary angiography. Surface morphology, presence of plaque, and percent area stenosis were determined with each procedure. Percutaneous coronary angioscopy was more sensitive in detecting the presence of plaque and stenosis than was coronary angiography (plaque: 79 vs 10% [p < 0.001]; and stenosis: 24 vs 3% [p < 0.01]). Intravascular ultrasound was also more sensitive in detecting plaque (76 vs 10%; p < 0.001) and stenosis (45 vs 3%; p < 0.001) than was coronary angiography. Although both angioscopy and ultrasound identified atherosclerotic plaque, only percutaneous coronary angioscopy could show luminal surface morphology and pigmentation of the plaque. Conversely, ultrasound could detect calcification and presence of intimal thickening, and was more accurate in assessing the severity of stenosis (45 vs 24%; p < 0.01). In conclusion, percutaneous coronary angioscopy and intravascular ultrasound, in conjunction, provide information not only regarding the appearance of the luminal surface, but also quantitative information regarding the structure and extent of the disease in the coronary artery wall.

Directional coronary atherectomy in heart transplant recipients

Cardiac allograft vasculopathy is one of the most common obstacles to the long-term survival of heart transplant recipients. Percutaneous transluminal angioplasty has been used as a palliative treatment for discrete lesions caused by this disease, but it is often complicated by restenosis. This report describes two cases in which directional coronary atherectomy was used to treat the discrete lesions and explores the possible advantages of this intervention in lieu of the traditional approach. Our results suggest that directional coronary atherectomy is a feasible alternative to conventional balloon angioplasty.

Chylous mesenteric and retroperitoneal cysts of developmental origin amongst Ethiopians: report of four cases

Chylous mesenteric and retroperitoneal cysts of developmental origin are unusual and rarely diagnosed with accuracy before laparotomy. They may produce compression of viscera and may rupture with haemorrhage. This is the first report of four cases, with varied presentations, from an African country.

Two-dimensional echocardiography and Doppler color flow mapping in the diagnosis and prognosis of ventricular septal rupture

Doppler color flow mapping in conjunction with two-dimensional echocardiography was used to evaluate ventricular septal rupture after myocardial infarction (seven anterior and eight inferior) in 15 patients and to correlate these findings with cardiac catheterization and surgical or autopsy data. Ventricular septal rupture was diagnosed by turbulent flow traversing the ventricular septum. The direction and velocity of shunt flow was determined by color M-mode and conventional Doppler methods. In all patients, Doppler color flow mapping correctly defined the site of septal rupture, which occurred at areas of discordant septal wall motion or "hinge points" (six posterior inlet, three anterior inlet, and six apical trabecular septum). Each of three patients with moderate tricuspid regurgitation and three of four patients with right-to-left shunting during diastole died, and all had an elevated right ventricular end-diastolic pressure. Right ventricular wall motion index was significantly higher in the patients who died compared with those who survived (mean +/- SEM; 2.8 +/- 0.2 vs. 2.0 +/- 0.2, p = 0.012), but there was no difference in left ventricular wall motion index. The rupture size measured by Doppler color flow imaging (1.7 +/- 0.1 cm) correlated with the size determined during surgery or autopsy (1.8 +/- 0.2 cm, r = 0.68, p = 0.022) and the pulmonic-to-systemic shunt flow ratio by cardiac catheterization (2.4:1 +/- 0.3, r = 0.74, p = 0.004). Color-guided continuous-wave Doppler estimates of right ventricular systolic pressure (47 +/- 2 mm Hg) correlated with cardiac catheterization measurements (48 +/- 3 mm Hg, r = 0.90, p = 0.0002).(ABSTRACT TRUNCATED AT 250 WORDS)

Tumoral calcinosis in Somalia and Ethiopia: a report of twenty one cases and brief review of literature

Tumoral calcinosis is an uncommon lesion of obscure aetiology often misdiagnosed. It occurs predominantly in the Negroid and African races, but there is paucity of African literature. This is the first report of eleven cases amongst Somalis and ten Ethiopians, involving only the greater trochanteric, gluteal and iliac crest regions. The clinical, radiological, macroscopical and histological features are typical and universally similar. It may grow rapidly, but usually, gradually over the years, more frequently at the pressure points. Multiple tumours do occur; affects both the sexes and all ages, but here all the Somalis were females. Most cases in both the countries were elderly (60 to 75 years of age) in contrast to other series. Wide surgical excision is essential to avoid recurrence.

A comparative study of pterion formation and its variations in the skulls of Nigerians and Indians

An attempt has been made to study and compare the incidence and variations in the pterion formation in the skulls of 40 Nigerians and 72 Indians obtained from the Department of Anatomy, University of Jos, Nigeria. The present study concludes: 1. All the three varieties of pterion i.e. sphenoparietal, frontotemporal and stellate are found in both races. 2. The frequency of sphenoparietal pterion is high in both races (Indians 95.3%, Nigerians 84.79%) while the frontotemporal (Indians 3.46%, Nigerians 10.11%) and the stellate (Indians 1.38%, Nigerians 5.06%) pterion are more common in Nigerians. 3. The frequency of epipteric bone is high in Indians (Indians 11.79%, Nigerians 3.79%) and is more commonly associated with sphenoparietal pterion. 4. No epipteric bone is associated with stellate pterion in both races. 5. The difference in the distance of pterion from the zygomatic arch is highly significant between two races on both sides. 6. The difference in the distance of pterion from the frontozygomatic suture is insignificant between the two races. 7. The frequency of "high Pterion" is more in Nigerians on both sides. 8. The frequency of "Backward Pterion" is more in Indians on the right side, whereas little more in Nigerians on the left side.

Age and wisdom teeth in Nigeria

An attempt has been made to estimate the eruption age of wisdom teeth in the North Nigerian population. The present study was carried out on 654 boys and 584 girls of age groups ranging from 11-23 years. From the data collected estimates have been provided for the eruption age of the third molar. In general, teeth of the lower jaw erupt before those of the upper jaw. The teeth on the left side erupt earlier than those on the right side. The wisdom teeth erupt little earlier amongst boys (18 years) as compared with girls (18.5 years). In general, the wisdom teeth erupt in Nigerians with some constancy between the age of 15 and 21. The wisdom teeth fail to erupt in 5% of the individuals.

Interparietal bones in Nigerian skulls

The study was conducted on 40 adult Nigerian skulls which were examined for the presence of interparietal and pre-interparietal bones. Only one interparietal bone was found (2.5% of the present series) while a single pre-interparietal bone was found in four skulls (10%) and multiple pre-interparietal bones in one skull (2.5%).

Anthropometric study of male external genitalia of 320 healthy Nigerian adults

Five basic measurements of the male external genitalia were studied in 320 healthy male medical students belonging to the various parts of Nigeria (West Africa). Their ages range from 17 to 23 years. The measurements were as follows: average length of the penis (81.6 +/- 0.94 mm); circumference of the penis (88.3 +/- 0.02 mm); circumference of the scrotum (212.6 +/- 2.48 mm); length of right testis (46.8 +/- 0.54 mm); width of right testis (32.4 +/- 0.37 mm); length of left testis (46.0 +/- 0.53 mm); and width of left testis (31.4 +/- 0.36 mm). The size of the genitalia increases with the increase in age in younger year groups. The adult stages of genitalia development are reached at the age of 21 years in 89.0% of the individuals. The growth of the genitalia is continued with the increasing height and weight, but this growth slows down after attaining a definite height and weight.

Ethnomedicinal plants of Jaunsar-Bawar hills, Uttar Pradesh, India

During an ethnomedicobotanical survey of Jaunsar-Bawar, a hilly tribal inhabited area in Uttar Pradesh, India, it was observed that about 100 plants are being used by the local Jaunsari tribe for the treatment of various ailments. An alphabetical list of these plants is given along with their family, local name, local uses, locality and collection number.

Variations in the articular facets of the adult cuneiform bones

This study was carried out on 300 adult cuneiform bones (100 each of medial, intermediate and lateral cuneiform bones) for variations in their articular facets. The bones under study are from the Department of Anatomy, University of Jos, Nigeria. In each group, 75 were male and 25 female bones. The difference in the incidence of various patterns of articular facets in the different cuneiform bones between males and females as well as between right and left sides was found to be statistically significant.

Incidence of the metopic suture in adult Nigerian skulls

This study was carried out on 206 adult Nigerian skulls for the incidence of the metopic suture. Metopism was present in 3.4% of cases, and a metopic suture (complete or incomplete) was observed in 34.97% of the skulls. The metopic suture was present in the lower part of the frontal bone, in various shapes, in 30.10% of cases. The most common shape observed was linear type (24.27%). Inverted U-shaped, and wide side to side excursion, were found in 0.49% of cases of each kind, these being the least common form of the suture. The incidence in the upper, upper middle and lower middle parts of the frontal bone was 0.49% in each type.

Effect of organo-tellurium compounds on the enzymatic alterations in rats

An attempt has been made to correlate early toxicity of organo-tellurium (Te) compounds with enzymic alterations in liver, kidney, brain and serum at 1 and 3 days following single i.p. injections of bis-(tetraphenyl phosphonium) tetracyanato-bis-p-methoxy p-phenyl tellurate(IV) (TTMT) and bis-(tetraheptyl ammonium) tetraiodocyclopentane tellurate(IV) (TACT). These compounds, at 2 and 1 mg Te/kg body weight as TTMT and TACT, respectively, produced cholinergic signs and caused death within 3 days. Administration at maximum tolerable doses of 0.5 mg and 0.1 mg Te/kg body weight as TTMT and TACT, respectively, resulted in significant reduction of acetylcholine esterase (AChE) and monoamine oxidase (MAO) in serum and brain and by a significant decrease in hepatic glutathione and in glutathione-S-transferase (GST) and alkaline phosphatase in liver and kidney.