Detoxification of cassava leaves by simple traditional methods

Cassava leaves, which usually contain large quantities of cyanogenic glycosides, were processed into a Zairian traditional vegetable sauce ‘Mpondu’ by simple methods which included blanching (10 min), mashing and then boiling for 20–80 min. These methods enhanced the detoxification of the leaves, with blanching alone resulting in the loss of 57% of the free (non-glycosidic) cyanide content and of 60% of the bound (glycosidic) cyanide. It is presumed that losses of cyanide during these processes would be accounted for in volatile HCN, its derivatives and in the boiling water

Biliary excretion of linamarin in the wistar rat after a single dose

The biliary excretion of linamarin (2[β-d-glucopyranosyloxy]isobutyronitrile) was studied in male albino Wistar rats injected i.p. with single doses of 300 mg linamarin/kg following cannulation of the bile duct in vivo; 24 hr faeces of uncannulated rats, similarly dosed, was examined for excretory products. Enzymatic and spectrophotometric analyses of the bile exudate showed that glucosidic cyanide (linamarin, and non-glucosidic cyanide were excreted; the elimination of both cyanide forms exhibits biphasic kinetics. Thiocyanate ion was undetectable. T.l.c. of the test bile followed by enzymatic and chemical investigation of the chromatogram confirmed the presence of unchanged linamarin, and four different u.v. fluorescent non-glucosidic cyanide metabolites. Neither linamarin nor cyanide ion was detectable in faeces of the uncannulated rat

Stomach Histopathologic and Ulcerogenic Potentials of Tea Beverage

Sixty four (64) albino rats were studied for possible histopathologic and ulcerogenic potentials of Lipton tea for the period of twenty eight days (28). The ulceration of the lumen of the stomach counted as ulcer points increased considerably within the 28 days duration, particularly 7-21 days. There were marked histologic changes as evidenced in the degeneration of gastric glands and cells due to loss of mucus such which were not found in the controls. Also the gastric pits were grossly dilated in 75% of the animals fed with Lipton tea while 15% had mild or no dilations of the gastric pits. Some of the dilated pits were filled with mucus absent in controls without Lipton tea. The oxyntic or parietal cells showed pale cytoplasm in contrast to eosinophilic staining affinity in controls. Particularly prominent was the decreases in the number of parietal cells, however such cells still maintained  normal large rounded morphology with round nuclei having nucleoli as in controls. Few mucus cells were observed in the clustered of mucus gland or mucuous neck cells as against many of such cells in controls. However the morphology and basal location of the cells nuclei and basophilic staining affinity were as in controls. It is concluded that Lipton tea has the tendency of inducing gastric ulcer, achlorhydria and pernicious anaemia. Keywords:  Lipton tea, Gastric, histopathology, ulcerogenic potentials

Dietary Thiocyanate and N-Nitrosation in vivo in the Wistar Rat

The influence of dietary thiocyanate (SCN-) on N-nitrosation in vivo was investigated over 14 min following the administration, by stomach tube, of single doses of sodium nitrite and dimethylamine hydrochloride to male albino Wistar rats whose diet contained appreciable quantities of bound cyanide (cyanogenic glycosides) and free (nonglycosidic) cyanide. The rate of disappearance of the nitrosating agent (NO-2 from the stomach in control animals showed a high linear correlation (r = -0.84) with gastric N-nitrosation, as measured by metabolism (N-demethylation) of ‘formed’ nitrosamine in liver tissue isolated from these animals. This statistical relationship was significantly increased (r = 0.98), as well as the rate of NO-2 utilization and the activity of the N-demethylase enzyme, in animals fed the test diet. Stomach SCN- content was well correlated with both stomach NO-2 concentration (r = -0.95) and liver N-demethylase activity (r = +0.93). Interactions, in vivo, between thiocyanate ion and nitrosamine precursors ingested in food may enhance nitrosamine carcinogenesis

The effect of the interaction of various spawn grains with different culture medium on carpophore dry weights and stipe and pileus diameters of Lentinus squarrosulus

Lentinus squarrosulus, an indigenous mushroom specie commonly found growing on dead logs in the Zaria environ of Kaduna State was cultured on six different medium which were inoculated separately with three different spawn grains and amended with six different oils at five different rates. The interaction of spawn grains x culture medium had a highly significant effect on carpophore dry weight and stipe and pileus diameters of L. squarrosulus. The results reveal that the interaction of millet spawn x animal bedding and rice medium induced the widest stipe diameter while the interaction of corn spawn x animal bedding and rice medium induced the heaviest carpophore dry weight as well as the widest pileus diameter. African Journal of Biotechnology Vol. 4 (7), pp. 615-619, 200

Effect of Thiamin Status on the Metabolism of Linamarin in Rats

The effect of graded levels of thiamin on the metabolism of linamarin was investigated in rats. It was observed that on a diet deficient in thiamin, a large amount of linamarin was recovered unchanged in the urine, together with significantly more thiocyanate (SCN–) relative to the control. The least amount of thiocyanate (p < 0.05 relative to control) was found in animals receiving the highest amount (twice daily requirement) of thiamin in the diet; but the amount of unmetabolized linamarin was similar to the control. It is suggested that thiamin deficiency may be implicated in the aetiology of tropical ataxic neuropathy (TAN) through the thiocyanate overload in people eating large amounts of cassava and cassava derivatives which contain linamari

The effects of the interaction of various oil types and rates on the mycelial wet and dry weights of Lentinus squarrosulus (Mont.) Singer and Psathyrella atroumbonata Pegler in submerged liquid cultures

Lentinus squarrosulus and Psathyrella atroumbonata, two edible indigenous mushroom species, were cultured in various different media supplemented with coconut, cotton, groundnut, butterfat, palm kernel and palm oil respectively, at 5 different rates. The interaction of the various oil types with different rates produced highly significant differences (

The effect of media, oil type and rate on the mycelia wet and dry weights of Lentinus squarrosulus (Mont.) singer and psathyrella patroumbonata pegler in submerged liquid culture

Lentinus squarrosulus and Psathyrella atroumbonata, two edible indigenous mushroom species, were cultured in four different submerged liquid media supplemented with coconut, cotton, groundnut, butterfat, palm kernel and palm oil at 5 different rates. The differences in the means due to the different media types were highly significant (

A Modified Real-Time Fault-Tolerant Task Allocation Scheme for Wireless Sensor Networks

In WSNs, the sensor nodes are at risk of failure and malicious attacks (selective forwarding). This may have a profound negative effect when you consider real-time WSNs, making them challenging to deploy. When there is a delay in tasks allocation execution processes in real-time WSNs because of sensor nodes failures, this will cause disastrous consequences if the systems are safety-critical, e.g. aircraft, nuclear power plant, forest fire detection, battlefield monitoring, thus the need to developed a real-time system that is fault-tolerable. This paper developed a modified real-time fault-tolerant task allocation scheme (mRFTAS) for WSNs (wireless sensor networks), using active replication techniques. mRFTAS and RFTAS performance were compared using time of execution of the task, network lifetime and reliability cost. The mRFTAS performance showed an improvement over that of RFTAS when it comes to reducing the time it takes for task execution by 45.56% and reliability cost of 7.99% while prolonging the network lifetime by 36.35%

Fate of ingested linamarin in malnourished rats

Pure linamarin at a dose level of 30 g per 100 g body weight was administered in food to a group of Wistar rats maintained on vitamin B2-deficient, sufficient and excess diets for 5 weeks and to another group of kwashiorkor rats. Free and total cyanide, intact linamarin and thiocyanate levels were estimated in urine and faeces obtained at 0-, 24-, 48- and 72-h periods and in blood samples obtained in the seventy-second hour after the drug had been administered. There was no detectable cyanide or intact linamarin in the faecal samples. Vitamin B2-sufficient and excess groups of rats excreted higher total and free cyanide than the respective vitamin B2-deficient groups. Most of the linamarin was degraded after the first 24h. The rate of breakdown of the glucoside within the first 24 h was slowest for the zero and half normal vitamin B2 status, respectively, as evidenced by its appearance in large quantities in the urine. The kwashiorkor rats, on the other hand, excreted less thiocyanate than the controls. In addition, their control group excreted most of the thiocyanate (SCN−) in the first 24 h whilst the kwashiorkor rats excreted theirs in the first 48 h. Dietary protein deficiency prolongs the time of metabolism and hence increases the toxicity of cyanogenic glycoside in the body. It is also suggested that excessive exposure of malnourished humans to cyanide could be a contributory factor in the rampant cases of tropical ataxic neuropathy (TAN)