The transversus abdominis plane block reduces the cumulative need of analgesic medication following inguinal hernia repair in TAPP technique: a retrospective single center analysis among 838 patients.

PURPOSE: Laparoscopic inguinal hernia repair (IHR) may lead to early postoperative pain. Therefore, opioid and non-opioid analgesic agents are often administered in the post-anesthesia care unit (PACU). To reduce the postoperative cumulative need of analgesic medication, as well as to accelerate the physical recovery time, the transversus abdominis plane (TAP) block has recently been studied. The TAP block is a regional anesthesia technique. Even though there is evidence about the efficacy of the block used in procedure such as an open inguinal hernia repair, the evidence regarding its use for the TAPP (transabdominal preperitoneal) technique remains low. We aim to provide more sufficient evidence regarding this topic. METHODS: A monocentric retrospective observational study investigating the effect of the TAP block prior to primary IHR in TAPP technique was conducted. The data of 838 patients who were operated on using this technique from June 2007 to February 2019 were observed. 72 patients were excluded because of insufficient information regarding their analgesic medication protocol. The patients' data were taken from their files. RESULTS: The patients in the TAP block group (n = 364) did not differ statistically significantly compared to the control group (n = 402) in terms of gender, BMI and age. Individuals of the TAP block group experienced less postoperative pain in the PACU (p < 0.001) and received less analgesic medication (morphine, oxycodone, piritramide, acetaminophen; p < 0.001). CONCLUSION: We assume that the TAP block is a sufficient approach to reduce postoperative pain and analgesic medication administration for IHR in TAPP technique.

Efficacy of T-2307, a novel arylamidine, against ocular complications of disseminated candidiasis in mice.

OBJECTIVES: T-2307, a novel arylamidine, shows broad-spectrum activity against pathogenic fungi, including Candida albicans. Ocular candidiasis is one of the serious complications associated with Candida bloodstream infection and is known to be refractory to conventional antifungal agents. The aim of the present study was to clarify the effectiveness of T-2307 against ocular candidiasis using a mouse model. METHODS: We evaluated ocular fungal burden in mice infected with C. albicans that received treatment with antifungal agents [T-2307, liposomal amphotericin B (LAMB) or fluconazole] for 3 consecutive days. We also assessed survival rates of mice after C. albicans infection followed by treatment for 7 consecutive days. In addition, ocular T-2307 concentrations and in vitro effectiveness against C. albicans biofilm formation were evaluated. RESULTS: The ocular fungal burdens were significantly reduced after T-2307 treatment compared with the control group (no treatment received) and were comparable with those observed following treatment with LAMB or fluconazole in both early- and late-phase treatment experiments. In addition, all of the mice treated with antifungal agents survived for 3 weeks after infection, whereas mice in the control group died within 3 days. The ocular T-2307 trough concentration was maintained above the MIC in the infected mice. An in vitro biofilm inhibition experiment showed that T-2307 suppressed C. albicans biofilm formation at the sub-MIC level, which was comparable with amphotericin B. CONCLUSIONS: Given these results in experimental disseminated candidiasis, T-2307 may be an effective treatment against the complication of ocular candidiasis.

In vitro and in vivo antifungal activities of T-2307, a novel arylamidine, against Cryptococcus gattii: an emerging fungal pathogen.

Objectives: T-2307, a novel arylamidine, exhibits potent broad-spectrum activities against the majority of fungal pathogens. In this study, the antifungal activity of T-2307 against Cryptococcus gattii was evaluated in comparison with those of amphotericin B, fluconazole and voriconazole in vitro and in vivo . Methods: The MICs for 15 clinical isolates were determined according to CLSI guidelines and time-kill studies were performed using C. gattii YF2784. In a murine model for intranasal pulmonary infection caused by C. gattii YF2784, the test compounds were administered once daily for 7 days from 2 h or 14 days post-infection. The viable counts in the lungs and brain were determined at 21 days post-infection. Results: The MIC range, MIC 50 , MIC 90 and geometric mean MIC of T-2307 were 0.0078-0.0625, 0.0313, 0.0625 and 0.0394 mg/L, respectively. The MIC of T-2307 was significantly lower than those of fluconazole, voriconazole and amphotericin B. T-2307 showed concentration-dependent fungicidal activity at 4 times the MIC or higher. Administration of T-2307 at 2 mg/kg/day, amphotericin B at 1 mg/kg/day and fluconazole at 160 mg/kg/day from 2 h post-infection significantly reduced viable counts in the lungs and brain. However, when the administration was started 14 days post-infection, only T-2307 significantly reduced the viable counts in both the lungs and the brain at 1 mg/kg/day. Conclusions: T-2307 shows excellent in vitro and in vivo antifungal activities against C. gattii and would be a promising new candidate for the treatment of cryptococcosis.

Inhibition of inducible nitric oxide synthase prevents shock wave therapy induced renal injury.

OBJECTIVES: Shock wave lithotripsy treatment (SWT) is not completely free from side effects; one of the accused mechanisms for renal injury during SWT is oxygen- and nitrogen-derived free radical productions. Therefore, we aimed to evaluate the effect of inhibition of nitric oxide (NO) production by N-[3(aminomethyl) benzyl) acetamidine] (1400W), highly selective inducible nitric oxide synthase (iNOS) inhibitor, at SWT-induced kidney damage. MATERIALS AND METHODS: Twenty-four rats those underwent right nephrectomy procedure were divided equally into three groups as control, SWT, and SWT + 1400W. 1400W was administered at a dose of 10 mg/kg at 2 h prior to SWT procedure and at the beginning of SWT procedure via intraperitoneal route and continued daily for consecutive 3 days. At the end of the fourth day, animals were killed via decapitation and trunk blood and the left kidneys were taken for biochemical and histopathologic evaluation. RESULTS: SWT caused renal tubular damage and increased lipid peroxidation and antioxidant enzyme activities and SWT also significantly increased nitro-oxidative products. Inhibition of iNOS via administration of 1400W ameliorated renal injury and decreased tissue lipid peroxidation (malondialdehyde), superoxide dismutase, glutathione peroxidase and nitrite/nitrate levels (NOx). In addition, it was seen that histolopathological changes were attenuated in the SWT + 1400W group when compared to SWT group. CONCLUSION: SWT-induced renal injury might be due to excessive production of oxygen free radicals and NO production. Inhibition of iNOS attenuates renal injury following SWT treatment. It can be concluded that iNOS inhibitors or peroxynitrite scavengers might be used to protect the kidneys against SWT-induced morphological and functional injuries.

In vitro and in vivo investigation of the efficacy of arylimidamide DB1831 and its mesylated salt form--DB1965--against Trypanosoma cruzi infection.

Chagas disease is caused by infection with the intracellular protozoan parasite Trypanosoma cruzi. At present, nifurtimox and benznidazole, both compounds developed empirically over four decades ago, represent the chemotherapeutic arsenal for treating this highly neglected disease. However, both drugs present variable efficacy depending on the geographical area and the occurrence of natural resistance, and are poorly effective against the later chronic stage. As a part of a search for new therapeutic opportunities to treat chagasic patients, pre-clinical studies were performed to characterize the activity of a novel arylimidamide (AIA--DB1831 (hydrochloride salt) and DB1965 (mesylate salt)) against T. cruzi. These AIAs displayed a high trypanocidal effect in vitro against both relevant forms in mammalian hosts, exhibiting a high selectivity index and a very high efficacy (IC(50) value/48 h of 5-40 nM) against intracellular parasites. DB1965 shows high activity in vivo in acute experimental models (mouse) of T. cruzi, showing a similar effect to benznidazole (Bz) when compared under a scheme of 10 daily consecutive doses with 12.5 mg/kg. Although no parasitological cure was observed after treating with 20 daily consecutive doses, a combined dosage of DB1965 (5 mg/kg) with Bz (50 mg/kg) resulted in parasitaemia clearance and 100% animal survival. In summary, our present data confirmed that aryimidamides represent promising new chemical entities against T. cruzi in therapeutic schemes using the AIA alone or in combination with other drugs, like benznidazole.

N-α-benzoyl-N5-(2-chloro-1-iminoethyl)-L-ornithine amide, a protein arginine deiminase inhibitor, reduces the severity of murine collagen-induced arthritis.

Rheumatoid arthritis is associated with the development of autoantibodies to citrullinated self-proteins. Citrullinated synovial proteins, which are generated via the actions of the protein arginine deiminases (PADs), are known to develop in the murine collagen-induced arthritis (CIA) model of inflammatory arthritis. Given these findings, we evaluated whether N-α-benzoyl-N5-(2-chloro-1-iminoethyl)-L-ornithine amide (Cl-amidine), a recently described pan-PAD inhibitor, could affect the development of arthritis and autoimmunity by treating mice in the CIA model with Cl-amidine on days 0-35. Cl-amidine treatment reduced total synovial and serum citrullination, decreased clinical disease activity by ∼50%, and significantly decreased IgG2a anti-mouse type II collagen Abs. Additionally, histopathology scores and total complement C3 deposition were significantly lower in Cl-amidine-treated mice compared with vehicle controls. Synovial microarray analyses demonstrated decreased IgG reactivity to several native and citrullinated epitopes compared with vehicle controls. Cl-amidine treatment had no ameliorative effect on collagen Ab-induced arthritis, suggesting its primary protective mechanism was not mediated through effector pathways. Reduced levels of citrullinated synovial proteins observed in mice treated with Cl-amidine are consistent with the notion that Cl-amidine derives its efficacy from its ability to inhibit the deiminating activity of PADs. In total, these results suggested that PADs are necessary participants in the autoimmune and subsequent inflammatory processes in CIA. Cl-amidine may represent a novel class of disease-modifying agents that modulate aberrant citrullination, and perhaps other immune processes, necessary for the development of inflammatory arthritis.

Novel oral factor Xa and thrombin inhibitors in the management of thromboembolism.

The last decade has seen the evaluation of several new oral anticoagulants that directly target thrombin or activated factor X (FXa). All demonstrate a rapid onset of action, a low potential for food and drug interactions, and a predictable anticoagulant effect that obviates the need for routine coagulation monitoring. Those agents at the most advanced stages of clinical development are a direct thrombin inhibitor, dabigatran, and direct FXa inhibitors, rivaroxaban and apixaban. Dabigatran and rivaroxaban are approved in more than 70 countries for prevention of venous thromboembolism in patients undergoing elective hip or knee arthroplasty, and apixaban is being considered for approval by regulatory agencies for this indication. Dabigatran was shown in a large phase III trial to be more effective and safer than warfarin for the prevention of stroke or systemic embolism in patients with atrial fibrillation and has recently been approved for this indication. Edoxaban, an oral FXa inhibitor, is also being evaluated in phase III clinical trials. This review summarizes the pharmacology, clinical trial results, and future role of the new oral anticoagulants in clinical practice.

Is there evidence to support the use of direct Factor Xa inhibitors in coronary artery disease?

As coronary artery disease (CAD) remains a leading cause of death in the world, the development of anti-coagulants to prevent CAD progressing to myocardial infarction and death is a high priority. A number of direct Factor Xa (FXa) inhibitors are being developed for use in CAD. Despite being developed to the stage of Phase II clinical trials, DX-9065a is no longer a priority with its developing company for further development, possibly because the Phase II trials did not show any major benefit of DX-9065a over heparin in subjects undergoing percutaneous coronary interventions (PCI) or with non-ST-elevation acute coronary syndromes (ACS). ZK-807834, otamixaban, apixaban, and rivaroxaban are all direct FXa inhibitors that have undergone preclinical and some clinical testing for use in CAD. In a large Phase II clinical trial of subjects with ACS, some doses of otamixaban had a better benefit/risk profile than the unfractionated heparin/eptifibatide combination. However, neither ZK-807834 nor otamixaban appear to be undergoing further clinical development at present. In ACS, placebo-controlled large Phase II clinical trials with apixaban and rivaroxaban have not shown clear cut benefits. Nevertheless, apixaban and rivaroxaban are presently in placebo-controlled Phase III clinical trials for ACS. Presently, there is no compelling evidence to support the use of direct FXa inhibitors in ACS.

Design and screening of ASIC inhibitors based on aromatic diamidines for combating neurological disorders.

Acid sensing ion channels (ASICs) are implicated in various brain functions including learning and memory and are involved in a number of neurological disorders such as pain, ischemic stroke, depression, and multiple sclerosis. We have recently defined ASICs as one of receptor targets of aromatic diamidines in neurons. Aromatic diamidines are DNA-binding agents and have long been used in the treatment of leishmaniasis, trypanosomiasis, pneumocystis pneumonia and babesiosis. Moreover, some aromatic diamidines are used as skin-care and baby products and others have potential to suppress tumor growth or to combat malaria. A large number of aromatic diamidines or analogs have been synthesized. Many efforts are being made to optimize the therapeutic spectrum of aromatic diamidines, i.e. to reduce toxicity, increase oral bioavailability and enhance their penetration of the blood-brain barrier. Aromatic diamidines therefore provide a shortcut of screening for selective ASIC inhibitors with therapeutic potential. Intriguingly nafamostat, a protease inhibitor for treating acute pancreatitis, also inhibits ASIC activities. Aromatic diamidines and nafamostat have many similarities although they belong to distinct classes of medicinal agents for curing different diseases. Here we delineate background, clinical application and drug development of aromatic diamidines that could facilitate the screening for selective ASIC inhibitors for research purposes. Further studies may lead to a drug with therapeutic value and extend the therapeutic scope of aromatic diamidines to combat neurological diseases.

Thermal sensitization through ROS modulation: a strategy to improve the efficacy of hyperthermic intraperitoneal chemotherapy.

BACKGROUND: The purpose of this study was to investigate whether modulation of cellular reactive oxygen species (ROS) provides a synergistic effect with hyperthermia to induce tumor cell death in a colon cancer cell line. MATERIALS AND METHODS: HT-29 colon cancer cells were exposed to heat (43 degrees C) in the presence of the ROS-generating drug, 2-2'-azobis-(2-amidinopropane) dihydrochloride (AAPH) for 1 h. Viable cell mass and apoptosis was measured by MTT and annexin V staining, respectively. Oxidative stress was evaluated by DCFH fluorescence. Protein levels were determined by Western blot analysis. RESULTS: A synergistic effect on cell viability with AAPH was noted under hyperthermic conditions as compared with hyperthermia alone (P < .05). The number of nonviable cells after hyperthermia and AAPH exposure was also significantly increased compared with AAPH at 37 degrees C (42% vs 20%, P < .05). ROS levels were increased modestly with AAPH at 37 degrees C, whereas they increased significantly in a dose-dependent manner with AAPH at 43 degrees C. Transient increases of phosphorylated-p38 and ERK and decreases in phosphorylated-AKT were observed in the cells exposed to AAPH at 43 degrees C. Pretreatment of inhibitors of p38 yielded additional decreases in cell mass when used in combination with AAPH and hyperthermia (P < .05). Increased expression of HSP 27 observed at 43 degrees C was abrogated with AAPH exposure. CONCLUSIONS: Oxidative stress increased the cytotoxic effects of hyperthermia in colon cancer cells. Thermal sensitization through modulation of cellular ROS may represent a novel approach to increase the efficacy of hyperthermia as an anticancer modality.

Effect of combining nicotinamide as a PARS-inhibitor with selective iNOS blockade during porcine endotoxemia.

OBJECTIVE: To investigate the effects of combined selective inducible nitric oxide synthase (iNOS) inhibition using 1400 W with nicotinamide (NAD) as a PARS-inhibitor on hepato-splanchnic hemodynamics, O(2) kinetics, and energy metabolism during hyperdynamic porcine endotoxemia. DESIGN: Prospective, randomized, controlled, interventional experiment. SETTING: Animal research laboratory. SUBJECTS: Seventeen domestic pigs. INTERVENTIONS: After 12 h of continuous i.v. endotoxin (LPS) infusion 17 pigs received either no drug (CON, n=9) or 1400 W, titrated to maintain mean arterial pressure (MAP) at pre-endotoxin level, plus 10 mg.kg.h NAD ( n=8;). Measurements were obtained before, 12 h, 18 h, and 24 h after starting LPS infusion. MEASUREMENTS AND RESULTS: In addition to systemic and pulmonary hemodynamics and gas exchange, we measured hepatic arterial and portal venous blood flow, liver and portal venous drained viscera O(2) exchange, ileal mucosal-arterial PCO(2) gap, and portal as well as hepatic venous lactate/pyruvate ratios. Expired NO and plasma nitrate levels were assessed as a parameter of NO production. Without affecting cardiac output, therapy maintained MAP and blunted the LPS-induced rise in expired NO levels, attenuated the progressive fall in liver lactate clearance, and blunted the impairment of hepato-splanchnic redox state. The rise of ileal mucosal-arterial PCO(2) gap was not influenced. CONCLUSIONS: Combining selective iNOS inhibition with NAD as a PARS blocker may prevent circulatory failure and attenuate the detrimental consequences of LPS in intestinal and hepatocellular energy metabolism. Given the potential hepatotoxicity of high-dose NAD treatment, more potent PARS blockers with higher selectivity might further enhance the benefit of this therapeutic approach.

Species-specific modulation of the nitric oxide pathway after acute experimentally induced endotoxemia.

OBJECTIVE: The derangement of the nitric oxide pathway is an important contributing factor to the pathogenesis of septic shock. The aim of this study was to investigate potential differences in modulation of such a pathway in two experimental models of endotoxemia. DESIGN: Prospective, randomized, placebo-controlled animal investigation. SETTING: Cardiovascular research laboratory. SUBJECTS: Male, anesthetized, and mechanically ventilated New-Zealand rabbits (n = 24) and Sprague-Dawley rats (n = 24). INTERVENTIONS: After pretreatment with 1400W (1 mg kg(-1) subcutaneously), an inhibitor of inducible nitric oxide synthase, animals received an intravenous bolus of Escherichia Coli lipopolysaccharides (5 mg kg(-1)). After 4 hrs, lungs, myocardial left ventricles, and aortas were collected. MEASUREMENTS AND MAIN RESULTS: Blood mean arterial pressure, pH, and nitrite/nitrate were monitored. Nitric oxide in the exhaled air was measured by chemiluminescence. Tissue activity of both constitutive nitric oxide synthase and inducible nitric oxide synthase was determined by measuring the conversion of [3H]L-arginine to [3H]L-citrulline. In lipopolysaccharide-treated animals, both mean arterial pressure (after 60 to 90 mins) and blood pH (after 4 hrs) decreased with respect to baseline values. 1400W prevented lipopolysaccharide-induced hypotension only in rats (p <.01). Exhaled nitric oxide decreased in lipopolysaccharide-treated rabbits by 120 mins (from 12.6 +/- 0.6 to 8.4 +/- 0.6 ppb, p <.01) and remained low until the end of the experiment (p <.01 vs. baseline). Conversely, exhaled nitric oxide increased in lipopolysaccharide-treated rats by 120 mins (from 0.4 +/- 0.1 to 5.3 +/- 1.7 ppb, p <.01) and reached a plateau by 210 mins (19.8 +/- 3.1 ppb, p <.01 vs. baseline). 1400W prevented the lipopolysaccharide-induced increase in exhaled nitric oxide and blood nitrite/nitrate in rats (p <.05). Inducible nitric oxide synthase activity increased in endotoxemic rabbit heart (0.19 +/- 0.05 vs. 0.07 +/- 0.02 pmol L-citrulline/min/mg protein in the control group, p <.05) and in all rat tissues, being more striking in the lungs (25.00 +/- 0.01 vs. 0.19 +/- 0.04 pmol L-citrulline/min/mg protein in the control group, p <.001). CONCLUSIONS: The nitric oxide pathway is differently modulated between endotoxemic rabbits and rats.

Mechanisms of inducible nitric oxide synthase (iNOS) inhibition-related improvement of gut mucosal acidosis during hyperdynamic porcine endotoxemia.

OBJECTIVE: To determine the mechanisms of improved gut mucosal acidosis associated with selective inducible nitric oxide synthase (iNOS) inhibition. DESIGN: Prospective, controlled experimental study. SETTING: Animal research laboratory. ANIMALS: Fourteen domestic pigs. INTERVENTIONS: Anesthetized and mechanically ventilated pigs received continuous i.v. endotoxin for 24 h. A selective iNOS-inhibitor (1400 W, n=8) or vehicle (control, n=6) was started at 12 h of endotoxin and infused until the end of the experiment. MEASUREMENTS AND RESULTS: Before as well as at 12 and 24 h of endotoxin, portal venous flow (ultrasound probe), intestinal oxygen (O(2)) extraction, portal venous-arterial carbon dioxide (CO(2)) content difference and ileal mucosal-arterial PCO(2) gap (fiberoptic sensor) were assessed together with video recordings of the villous microcirculation (number of perfused/unperfused villi) using orthogonal polarization spectral imaging via an ileostomy. The gut wall microvascular blood flow (units) and hemoglobin O(2) saturation ( micro Hb-O(2)) were assessed with a combined laser Doppler flow and remission spectrophotometry probe. 1400 W blunted the otherwise progressive rise in the PCO(2) gap without affecting portal venous flow, regional O(2) and CO(2) exchange or the number of unperfused villi. While endotoxin markedly aggravated the heterogeneity of the microvascular blood flow and oxygenation, 1400 W had no further effect. CONCLUSIONS: Given the uninfluenced parameters of the ileal mucosal microcirculation in our model of long-term porcine endotoxemia, selective iNOS inhibition probably improved the PCO(2) gap due to a redistribution of the microvascular perfusion within the gut wall and/or an amelioration of the cellular respiration.

The antithrombotic efficacy of AT-1459, a novel, direct thrombin inhibitor, in rat models of venous and arterial thrombosis.

The antithrombotic efficacy of AT-1459, a novel, direct thrombin inhibitor (Ki = 4.9 nM) was evaluated in rat models of venous thrombosis combined with a bleeding time test and arterial thrombosis. After drugs were given by i. v. bolus injection plus a continuous infusion, the ID50, (a dose that exhibits 50% inhibition of thrombus formation over each vehicle group) values of AT-1459, argatroban, and dalteparin were 0.04 mg/kg plus 0.04 mg/kg/h, 0.1 mg/kg plus 0.4 mg/ kg/h, and 13.0 IU/kg plus 26.0 IU/kg/h, respectively, in the venous thrombosis study. The BT2 (a dose that causes 2-fold prolongation of bleeding time over each vehicle group) values of AT-1459, argatroban, and dalteparin were 0.9 mg/kg plus 0.9 mg/kg/h, 1.0 mg/kg plus 0.6 mg/kg/h, and 345.5 IU/kg plus 691.0 IU/kg/h in the rat tail transection model. The ratios of BT2/ID50 of AT-1459, argatroban, and dalteparin were 22.5, 10.0, and 26.6, respectively. In a rat model of arterial thrombosis induced by topical FeCl2 application, intravenous administration of AT-1459, argatroban, and dalteparin improved the vessel patency significantly (P < 0.01) at 0.6 mg/kg plus 0.6 mg/kg/h, 0.6 mg/kg plus 2.4 mg/kg/h, and 300 IU/kg plus 600 IU/kg/h, respectively. The oral antithrombotic effect of AT-1459 lasted for 6 after administering 30 mg/kg and improved the vessel patency significantly 1 h after administering the same dose in venous and arterial thrombosis models, respectively, with a rapid onset of action. Warfarin also inhibited thrombus weight and improved the vessel patency significantly after oral administration of 0.3 mg/kg for three consecutive days in the same study. The antithrombotic and hemorrhagic effects of all drugs studied were correlated with plasma concentration or clotting times. These results suggest that AT-1459 may be clinically useful as an orally available antithrombotic agent for the prevention of venous and arterial thrombosis.

Maternally derived immunity in young mice to infection with Trypanosoma brucei and its potentiation by Berenil chemotherapy.

Young mice which were allowed to suckle, from birth, a mother infected with Trypanosoma brucei, or a mother whose infection had been cured before parturition with Berenil chemotherapy, were themselves immune to homologous trypanosome challenge. This immunity extended until approximately 25 days of age, and was transmitted in the colostrum/milk of the mother. Mice born of infected mothers, but transferred at birth to normal foster mothers, were susceptible to trypanosome infection. Drug prophylaxis in normal newborn mice was also effective for approximately 25 days, but in mice which, in addition, received colostral antibody from the mother, combined immunochemoprophylaxis protected the offspring for 40-50 days. Since the combination of protective strategies continued to resist challenge beyond the stage when, on its own, each component's efficacy had decayed, it may be of practical value as an approach to improved disease control under certain field conditions where trypanosomiasis prevails.

Visceral leishmaniasis unresponsive to antimonial drugs. II. Response to high dosage sodium stibogluconate or prolonged treatment with pentamidine.

Ten Kenyan patients with visceral leishmaniasis unresponsive to sodium stibogluconate, at a dose of 16 to 20 mg Sb/kg body-weight/day given for 30 to 98 days, were treated with 20 mg Sb/kg bw given every eight hours. This regimen was modified or abandoned in six patients because of suspected toxicity, although toxicity was difficult to assess because of intercurrent illness. Toxic effects included lethargy, anorexia, vomiting, electrocardiographic changes, fall in haemoglobin and rise in liver enzymes. One patient died, probably from a cardiac arrhythmia. Two patients were cured, four responded partially and four showed no response. Pentamidine, at a dose of 4 mg/kg body-weight given one to 3 times per week for 5 to 39 weeks, was given as initial treatment in one patient and after failure of sodium stibogluconate in seven. Toxic effects included nephritis, hepatitis, transient diabetes and subcutaneous abscesses. Two patients were cured, two responded partially, three showed no response and one, after apparent cure, relapsed and was unresponsive to additional pentamidine treatment. Low-frequency, long-duration pentamidine was often useful in maintaining any improvement made during treatment with the less well tolerated high-dose, high frequency sodium stibogluconate. We observed the step-wise development of resistance to both sodium stibogluconate and pentamidine. The problems of managing patients with visceral leishmaniasis which is unresponsive to conventional doses of pentavalent antimonials are discussed and some tentative suggestions put forward.

Leishmania tropica major: effect of paromomycin and pentamidine on polyamine levels in the skin of normal and infected mice.

The polyamine content of the skin of BALB/c and C3H mice was determined at intervals, after injecting Leishmania tropica major. In BALB/c mice, putrescine and spermidine levels increased three- to seven-fold; in C3H mice, spontaneous recovery occurred after 3 weeks, accompanied by a reduction in putrescine and spermidine levels. Ornithine decarboxylase activity was negligible in normal, uninfected skin of both BALB/c and C3H mice, but increased steadily during infection. Treatment with drugs that inhibit the growth of leishmanial amastigotes in the skin of mice also reduced polyamine levels and ornithine decarboxylase activity of previously infected skin. There was a close correlation between the therapeutic activity of the drugs and their effect on polyamine content and synthesis. The aminoglycoside paromomycin, which was chemotherapeutically more effective than pentamidine, also had a greater effect on polyamine levels. S-adenosyl-L-Methionine decarboxylase activity in the skin of BALB/c and C3H mice was only slightly affected by the parasites. Polyamine levels and ornithine decarboxylase activity could possibly serve as means for measuring the growth of leishmanial parasites in skin and other tissues and as a measure of the efficacy of anti-leishmanial chemotherapeutics.

Action of p-(4-amidino-phenoxy)-benzaldehyde-p-amidino-phenylhydrazone dihydrochloride on Leishmania donovani infections in the golden hamster.

The chemotherapeutic effect of a new diamidine, HOE 668, the p-(4-amidino-phenoxy)-benzaldehyde-p-amidino-phenylhydrazone dihydrochloride, was compared with that of known anti-leishmanial drugs in golden hamsters infected with Leishmania donovani. The effect of HOE 668 against visceral leishmaniasis proved superior to that of pentamidine isethionate and the pentavalent antimonial drugs, sodium stibogluconate and N-methylglucamine antimoniate. However, HOE 668 can be used only experimentally because of its toxicity. Its very good anti-leishmanial action qualifies HOE 668 as a standard compound in screening tests.