Fatty acid synthase as a potential therapeutic target in feline oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is an aggressive and treatment-resistant malignancy in both feline and human patients. Recent work has demonstrated aberrant expression of fatty acid synthase (FASN) and an increased capacity for lipogenesis in human OSCC and other cancers. In human OSCC, inhibition of FASN decreased cell viability and growth in vitro, and diminished tumour growth and metastasis in murine preclinical models. This study aimed to characterize FASN as a therapeutic target in feline OSCC. Immunohistochemistry revealed high FASN expression in primary feline OSCC tumours, and FASN expression was detected in OSCC cell lines (3 feline and 3 human) by immunoblotting and quantitative real-time-polymerase chain reaction (qRT-PCR). Orlistat, a FASN inhibitor, substantially reduced cell viability in both feline and human OSCC lines, although feline cell lines consistently displayed higher sensitivity to the drug. FASN mRNA expression among cell lines mirrored sensitivity to orlistat, with feline cell lines expressing higher levels of FASN. Consistent with this observation, diminished sensitivity to orlistat treatment and decreased FASN mRNA expression were observed in feline OSCC cells following incubation under hypoxic conditions. Treatment with orlistat did not potentiate sensitivity to carboplatin in the cell lines investigated; instead, combinations of the 2 drugs resulted in additive to antagonistic effects. Our results suggest that FASN inhibition is a viable therapeutic target for feline OSCC. Furthermore, cats may serve as a spontaneous large animal model for human oral cancer, although differences in the regulation of lipogenesis between these 2 species require further investigation.

Impact of pigeon pea biochar on cadmium mobility in soil and transfer rate to leafy vegetable spinach.

Introduction of heavy metals in the environment by various anthropogenic activities has become a potential treat to life. Among the heavy metals, cadmium (Cd) shows relatively high soil mobility and has high phyto-mammalian toxicity. Integration of soil remediation and ecosystem services, such as carbon sequestration in soils through organic amendments, may provide an attractive land management option for contaminated sites. The application of biochar in agriculture has recently received much attention globally due to its associated multiple benefits, particularly, long-term carbon storage in soil. However, the application of biochar from softwood crop residue for heavy metal immobilization, as an alternative to direct field application, has not received much attention. Hence, a pot experiment was conducted to study the effect of pigeon pea biochar on cadmium mobility in a soil-plant system in cadmium-spiked sandy loam soil. The biochar was prepared from pigeon pea stalk through a slow pyrolysis method at 300 °C. The experiment was designed with three levels of Cd (0, 5, and 10 mg Cd kg(-1) soil) and three levels of biochar (0, 2.5, and 5 g kg(-1) soil) using spinach as a test crop. The results indicate that with increasing levels of applied cadmium at 5 and 10 mg kg(-1) soil, the dry matter yield (DMY) of spinach leaf decreased by 9.84 and 18.29 %, respectively. However, application of biochar (at 2.5 and 5 g kg(-1) soil) significantly increased the dry matter yield of spinach leaf by 5.07 and 15.02 %, respectively, and root by 14.0 and 24.0 %, respectively, over the control. Organic carbon content in the post-harvest soil increased to 34.9 and 60.5 % due to the application of biochar 2.5 and 5 g kg(-1) soil, respectively. Further, there was a reduction in the diethylene triamine pentaacetic acid (DTPA)-extractable cadmium in the soil and in transfer coefficient values (soil to plant), as well as its concentrations in spinach leaf and root, indicating that cadmium mobility was decreased due to biochar application. This study shows that pigeon pea biochar has the potential to increase spinach yield and reduce cadmium mobility in contaminated sandy soil.

Tumour, Oxidative Stress and Host T Cell Response: Cementing the Dominance.

Reactive oxygen species (ROS) and free radicals are produced intrinsically during normal cellular metabolic processes or extrinsically due to ionizing radiations, UV rays, xenobiotic insult, etc. ROS are important signal mediators and are used by the immune system to destroy pathogens, but as these are highly reactive, they also have the capacity to cause DNA damage and alter protein and lipid components of a cell. As a result, cells have evolved a tight regulation of internal redox environment that involves a balanced interplay between free radicals produced and quenched by cellular antioxidants and enzyme systems. Any deregulation of this subtle balance can result in oxidative stress that can lead to various pathological conditions including cancer. Oxidative stress can be a cause of neoplasia, or it can be induced by a growing tumour itself. The link existing between oxidative stress and inflammation is also very strong. Suppressed cellular immune system, especially effector T cell system, is a characteristic of tumour-bearing host. Both the direct oxidative stress caused by tumour cell(s) and oxidative stress mediators present in tumour microenvironment play a significant role in the suppression of effector T cell function and induction of T cell death. This review discusses in detail the complex interplay between tumour-stroma-immune system in the light of oxidative stress that dominates every phase of cancer including initiation, progression and establishment. This review also addresses in detail the mechanisms of oxidative stress-induced T cell dysfunction in tumour-bearing host and also briefly points out the possible therapeutic interventions.

Understanding cancer development processes after HZE-particle exposure: roles of ROS, DNA damage repair and inflammation.

During space travel astronauts are exposed to a variety of radiations, including galactic cosmic rays composed of high-energy protons and high-energy charged (HZE) nuclei, and solar particle events containing low- to medium-energy protons. Risks from these exposures include carcinogenesis, central nervous system damage and degenerative tissue effects. Currently, career radiation limits are based on estimates of fatal cancer risks calculated using a model that incorporates human epidemiological data from exposed populations, estimates of relative biological effectiveness and dose-response data from relevant mammalian experimental models. A major goal of space radiation risk assessment is to link mechanistic data from biological studies at NASA Space Radiation Laboratory and other particle accelerators with risk models. Early phenotypes of HZE exposure, such as the induction of reactive oxygen species, DNA damage signaling and inflammation, are sensitive to HZE damage complexity. This review summarizes our current understanding of critical areas within the DNA damage and oxidative stress arena and provides insight into their mechanistic interdependence and their usefulness in accurately modeling cancer and other risks in astronauts exposed to space radiation. Our ultimate goals are to examine potential links and crosstalk between early response modules activated by charged particle exposure, to identify critical areas that require further research and to use these data to reduced uncertainties in modeling cancer risk for astronauts. A clearer understanding of the links between early mechanistic aspects of high-LET response and later surrogate cancer end points could reveal key nodes that can be therapeutically targeted to mitigate the health effects from charged particle exposures.

Splenic metastasis and bleeding manifestations--an unusual association with gastric malignancy.

Splenic metastasis is a rare clinical entity--incidence being 0.6% at autopsy and 1.1% at splenectomy. We report the case of a 30 year old female who presented with purpura and melena and who was later diagnosed to have a mucinous adenocarcinoma of stomach with disseminated intravascular coagulation and splenic metastasis.

An epidemiological study on risk factors of diabetes mellitus among patients attending a medical college hospital in Kolkata, West Bengal.

Two hundred and thirty cases of diabetes mellitus were selected in a case-control fashion by applying systemic random sampling technique taking 20% of the patients attending the diabetic clinic of Calcutta National Medical College during the period from January to June, 2003 to find out association and risks of some socio-economic and demographic factors with the occurrence of diabetes mellitus. Controls were selected from the patients admitted in the department of surgery in the same period. Factors like physical activity, socio-economic status, residential status, family history and obesity have shown statistically significant association with diabetes. For physical activity the estimated relative risk is maximum in case of sedentary worker where the odd's ratio was 9.4. So far other factors are concerned the estimated relative risk of diabetes was 5.1 in case of urban population, 6.2 in case of positive family history, 2.5 in case of upper and upper middle classes, and 2.4 in case of obesity in comparison to their respective reference category.

[Short-term therapeutic fasting in the treatment of chronic pain and fatigue syndromes--well-being and side effects with and without mineral supplements]. / Kurzzeitiges therapeutisches Fasten in der Behandlung von chronischen Schmerz- und Erschöpfungssyndromen - Verträglichkeit und Nebenwirkungen mit und ohne begleitende Mineralstoffergänzung.

BACKGROUND: Fasting followed by vegetarian diet has shown to be an effective treatment for rheumatoid arthritis, moreover fasting is frequently used as an adjunctive treatment in chronic pain and stress/exhaustion syndromes. Data on well-being and the frequency of side effects during fasting are mostly retrospective. Mineral supplements are frequently used in order to compensate for fasting-induced tissue acidosis and to reduce side effects. There are only limited data that support this practice. OBJECTIVE: To study the effects of oral mineral supplements on common side effects and well-being during short-term fasting. PATIENTS AND METHODS: 209 consecutive inpatients with chronic pain/exhaustion syndromes were recruited. In a controlled non-randomised study design all patients underwent fasting (250 kcal; 3 l fluid intake/day) over 7 days, in study phase 1 without (n = 103) and in study phase 2 with (n = 106) concomitant prescription of standardised oral mineral supplements (3 x 2 to 3 x 3 Bullrich's Vital). Weight, blood pressure and urinary pH were recorded daily. Well-being and mood as well as common side effects (i.e. fatigue, hunger, heart burn, headache) were assessed with standardised self-reports. RESULTS: Baseline characteristics of the 209 patients (mean age 54.7 +/- 10.5 years; 83.3% female) were balanced. Both groups showed a fasting-induced decrease of blood pressure, a slight decrease in mood and well-being on days 3 and 4 with consecutive increase and moderate hunger, i.e. in the evening. Side effects and general tolerability of fasting as well as well-being and mood were not different between the groups. There were no serious side effects in both groups. CONCLUSIONS: Short-term fasting in inpatients with pain and stress syndromes is safe and well tolerated, concomitant mineral supplements have no additive benefit.

Pigmented nails and Strongyloides stercoralis infestation causing clinical worsening in a patient treated for immunoproliferative small intestinal disease: two unusual observations.

Immunoproliferative small intestinal disease (IPSID) is commonly reported from developing countries with poor socioeconomic conditions, hygiene, and high frequency of gastrointestinal infections and infestations. The disease requires anti-malignant chemotherapy in lymphomatous stage. Reported here is a 20-year old man with IPSID lymphoma who responded to anti-malignant chemotherapy initially, but later deteriorated due to Strongyloides stercoralis infestation, which was treated successfully with mebendazole. Importance of an early recognition and adequate treatment for gastrointestinal infections and infestations before anti-malignant chemotherapy for this disease is highlighted considering the occurrence of this disease in the developing world. The patient developed alternate brown black and white lines in the finger nails after combination chemotherapy, which has not been reported earlier in this disease; the nail changes disappeared 6 months after the withdrawal of doxorubicin suggesting this drug as the cause for such nail changes during anti-malignant combination chemotherapy.

Randomized placebo-controlled trial of 2,3-dimercaptosuccinic acid in therapy of chronic arsenicosis due to drinking arsenic-contaminated subsoil water.

INTRODUCTION: Chronic arsenic toxicity producing various clinical manifestations is currently epidemic in West Bengal, India, Bangladesh, and other regions of the world. Animal studies have indicated that 2,3-dimercaptosuccinic acid can be used as an oral chelating agent. A prospective, double-blind, randomized controlled trial was carried out to evaluate the efficacy and safety of 2,3-dimercaptosuccinic acid for chronic arsenicosis due to drinking arsenic-contaminated (> or = 50 micrograms/L) subsoil water in West Bengal. METHOD: Twenty-one consecutive patients with chronic arsenicosis were individually randomized (random number; assignment made by individual not evaluating patients) into 2 groups: 11 patients (10 male, age 25.5 +/- 8 years) received 2,3-dimercaptosuccinic acid 1400 mg/d (1000 mg/m2) in the first week and 1050 mg/d (750 mg/m2) during the next 2 weeks with a repeat course 3 weeks later. The other 10 patients (all male, age 32.2 +/- 9.7 years) were given placebo capsules for the same schedule. The clinical features were evaluated by an objective scoring system before and after treatment. Routine investigations including liver function tests, arsenic concentrations in urine, hair, and nails, and skin biopsy evaluations were also completed. RESULTS: Though there was improvement in the clinical score of 2,3-dimercaptosuccinic acid-treated patients, similar improvement was observed in the placebo-treated group. There were no statistical differences in the clinical scores between the 2 groups at the beginning and at the end of treatment. Similarly, no differences were found for the other investigated parameters. CONCLUSION: Under the conditions of this study, 2,3-dimercaptosuccinic acid was not effective in producing any clinical or biochemical benefit or any histopathological improvement of skin lesions in patients with chronic arsenicosis.

Effect of ATP on smooth muscle of toad urinary bladder.

Adenosine 5'-triphosphate (ATP), at a dose range of 1.8 to 116 microM, produced an initial phasic contraction followed by a rhythmic contraction in urinary bladder smooth muscle of the toad (Bufo melanostictus). Acetylcholine produced a rhythmic contraction which was antagonized by atropine (1.5 microM) and potentiated by neostigmine (1.7 microM), indicating activation of muscarinic receptors. However, both phasic and rhythmic components of ATP contraction were atropine-resistant. Quinidine (26-264 M) abolished the responses to ATP and acetylcholine, while indomethacin (28 microM) and theophylline (55 microM) antagonized only the acetylcholine responses. Repeated application of alpha, beta-methylene ATP desensitized the receptors and completely abolished contraction. ATP did not produce a phasic contraction in alpha, beta-methylene ATP-desensitized tissue, indicating that both ATP and its alpha, beta-methylene analogue occupy the same receptor site for phasic contraction. On the other hand, the rhythmic contraction induced by ATP remained unaffected in alpha, beta-methylene ATP-treated tissue. The phasic contraction in response to ATP can be blocked by verapamil (4 microM), but rhythmic contraction can only be abolished by a high concentration of verapamil (16 microM). Moreover, ATP produced no response in Ca+(+)-free or EGTA-containing solution, showing thereby that contractile responses to ATP are dependent upon extracellular Ca(+)+. These results indicate that the phasic component is a P2x-receptor-activated response while the rhythmic component might be an opening of calcium ion channels, either by depolarization of the membrane or by some unknown mechanism.

Effects of nicotine on spontaneous contractions of isolated atria of toad (Bufo melanostictus).

In toad atria, nicotine, at low concentrations (6.1 X 10(-6) M to 6.2 X 10(-5) M), produced a negative inotropic effect, and, at high concentrations (6.2 X 10(-4) M to 3.1 X 10(-3) M), a positive inotropic effect. The negative inotropism was potentiated by physostigmine or neostigmine and was antagonized by atropine or hemicholinium-3. The positive inotropism remained unaffected by exposure to phenoxybenzamine, phentolamine, propranolol, guanethidine, bretylium, hexamethonium, hemicholinium-3 or pretreatment with 6-OHDA or tyramine tachyphylaxis. The positive inotropism was antagonized by ethylene diamine tetraethyl acetate, verapamil or calcium-free Ringer. Caffeine induced positive inotropic effects, which were antagonized only by EDTA, and remained unaffected by exposure to verapamil or calcium-free Ringer. These results suggest a cholinergic mechanism for the negative inotropism produced by low concentrations of nicotine and also that the primary site of action of nicotine, when added at high concentrations, is the sarcolemmal calcium channel of toad atria resulting in increased calcium influx. They further suggest that the nicotine-induced positive inotropism is not mediated through activation of atrial adrenoceptors, ganglionic activation, presynaptic liberation of acetylcholine or liberation of catecholamine from sympathetic nerve endings.

Pharmacological and electrophysiological analysis of the effects of nicotine on cat blood pressure.

Nicotine (20-60 micrograms/kg) produced an initial vasodepressor response followed by a vasopressor response in anaesthetized cats, the mechanism of which was investigated. The vasodepressor response was antagonized by atropine or by vagotomy and was potentiated by physostigmine or neostigmine. Nicotine increased the single unit activity of different peripheral sympathetic nerves and evoked contraction of nictitating membrane and spleen along with vasopressor response. The vasopressor response was antagonized by phentolamine, prazosin, guanethidine, bretylium, 6-OHDA, hemicholinium-3 or hexamethonium. Propranolol or atenolol pretreatment potentiated the vasodepressor response and was antagonized by atropine. Desensitization by salbutamol did not modify the response to nicotine. The biphasic response to nicotine remained unaltered in yohimbine pretreated, in adrenalectomized, and in acute spinal as well as in decapitated animals; intracarotid or intracerebroventricular administration of nicotine did not produce any response. The biphasic response to nicotine does not involve the stimulation of the central vasomotor centre. In conclusion, these results suggest that the vasodepressor response is due to the vagal cholinergic mechanism. The vasopressor response is a consequence of activation of different peripheral adrenergic nerves causing increased release of the adrenergic transmitter at the neuroeffector region and the alpha 1-adrenoceptor mediate vasoconstriction in the systemic vascular bed.

The role of calcium channel in the effect of nicotine on contractility in isolated toad ventricle.

The mechanism of the positive inotropic effect produced by nicotine (6.2 X 10(-5) mol/l to 4.9 X 10(-4) mol/l) on electrically driven toad ventricles was investigated. The response to nicotine was not affected by 6-hydroxydopamine pretreatment, bretylium (2.4 X 10(-4) mol/l) exposure or tyramine tachyphylaxis. Following desensitisation by isoprenaline (4.2 X 10(-6) mol/l) of the beta-adrenoceptor in the ventricles, the response to nicotine was no affected. However, the response was antagonised by ethylene diamine tetraethyl acetate (2.3 X 10(-4) mol/l), verapamil (0.4 X 10(-5) mol/l) or calcium-free Ringer. Nicotine prolonged the action potential duration and enhanced the force of contraction. Nicotine induced slow action potentials in partially depolarized (in high potassium solution) ventricles and this was antagonised by verapamil (0.4 X 10(-5) mol/l). These results suggest that the effects of nicotine are mediated by a direct interaction with the Ca2+ channels at the cell surface.

The effects of nicotine on spontaneous contractions of cat urinary bladder in situ.

Nicotine and dimethyl-phenylpiperazinium (DMPP) increased intravesicular pressure and then transiently depressed the spontaneous activity of the urinary bladder in chloralose anaesthetized cats. Adrenaline (5-10 micrograms kg-1), noradrenaline (5-20 micrograms kg-1) and isoprenaline (40-50 micrograms kg-1) which depressed spontaneous urinary bladder activity, were antagonized by the beta-receptor blocking agent propranolol (1 mg kg-1). Phenylephrine (10-30 micrograms kg-1) was ineffective on the urinary bladder though it increased the systemic blood pressure. This latter effect was blocked by the alpha-receptor blocking agent phentolamine (2 mg kg-1). Acetylcholine (2-8 micrograms kg-1) caused a marked fall in systemic blood pressure, which was potentiated by physostigmine, but failed to produce any response on the intravesicular pressure even after physostigmine (50-100 micrograms kg-1) treatment. ATP (2 mg kg-1) produced an increase in intravesicular pressure accompanied by a fall in systemic blood pressure. The increased intravesicular pressure was antagonized by quinidine (20 mg kg-1); however, the fall in blood pressure remained unaltered. The increased intravesicular pressure induced by nicotine (20-40 micrograms kg-1) or DMPP (50-100 micrograms kg-1) was not affected by phentolamine (2 mg kg-1), propranolol (1 mg kg-1) or guanethidine (15-20 mg kg-1). Physostigmine (50-100 micrograms kg-1), hemicholinium 3 (2 mg kg-1) or atropine (1 mg kg-1) were also unable to affect the response to nicotine. Hexamethonium (1 mg kg-1), reduced the amplitude of spontaneous bladder contractions and quinidine (20 mg kg-1) abolished the effect of nicotine. 7 Bilateral sectioning of the cervical sympathetic or hypogastric nerves did not alter the effect of nicotine or DMPP. Higher spinal cord transection (Cl-C2) blocked the spontaneous, as well as the nicotine- and DMPP-induced, contractions of the bladder. 8 It is concluded that the increase in intravesicular pressure induced by nicotine is atropineresistant and is not mediated either through adrenergic or cholinergic mechanisms. It is probable that a purinergic mechanism is involved, via the activation of P2-receptors present in the urinary bladder.

Positive inotropic effect of nicotine on electrically evoked contraction of isolated toad ventricle.

The mechanism of the responses of nicotine on electrically evoked contractions of the isolated spirally cut toad ventricle was investigated. Nicotine produced a concentration-dependent positive inotropic effect of the ventricle. Prior administration of propranolol, hexamethonium, hemicholinium-3 or guanethidine failed to antagonize the positive inotropic effect of nicotine, thus ruling out the possibility of the nicotine effect being mediated through activation of beta-adrenoceptors, ganglionic activation, presynaptic liberation of acetylcholine and liberation of norepinephrine from the sympathetic nerve endings respectively. The positive inotropic effect is probably mediated through mobilisation of calcium since prior incubation with verapamil--the calcium transport blocker, EDTA, which chelates the extracellular calcium and calcium-free Ringer prevented the positive inotropic effect of nicotine. These results suggest that the positive intropic effect of nicotine may presumably be due to the facilitating effects of nicotine on Ca++ exchange or mobilisation of membrane bound Ca++.