Developmental regulation of polyamine metabolism in growth and differentiation of carrot culture

Polyamine levels and the activities of two polyamine biosynthetic enzymes, arginine decarboxylase (EC 4.1.1.19) and S-adenosylmethionine decarboxylase (EC 4.1.1.50), were determined during somatic embryogenesis of carrot (Daucus carota L.) cell cultures. Embryogenic cultures showed severalfold increases in polyamine levels over nondifferentiating controls. A mutant cell line that failed to form embryos but grew at the same rate as the wild-type line also failed to show increases in polyamine levels, thus providing evidence that this increased polyamine content was in fact associated with the development of embryos. Furthermore, inhibition of these increases in polyamines caused by drugs inhibited embryogenesis and the effect was reversible with spermidine. The activities of arginine decarboxylase and Sadenosylmethionine decarboxylase were found to be suppressed by auxin; however, the specific effects differed between exogenous 2,4-dichlorophenoxyacetic acid and endogenous indole-3-acetic acid. The results indicate that increased polyamine levels are required for cellular differentiation and development occurring during somatic embryogenesis in carrot cell cultures.

Chinese hamster ovary cells resistant to alpha-difluoromethylornithine are overproducers of ornithine decarboxylase

The selection of Chinese hamster ovary cells resistant to ornithine analogues has been extended to very high levels of the suicide inhibitor alpha-difluoromethylornithine. Stepwise selections resulted in stepwise increases in the inducible levels of ornithine decarboxylase activity. The enzyme is shown by several criteria to be normal in every respect: regulation in the cell cycle, inhibition by antizyme, absolute specific activity as determined with the help of alpha-[3H]difluoromethylornithine. The enzyme has been highly purified from such overproducing cells. The subunit molecular weight of the mammalian enzyme has been confirmed to be approximately 54,000. The location of the enzyme in two-dimensional polyacrylamide gel electrophoresis was determined, and the protein could be detected on two-dimensional gels with extracts from our best overproducers.

Dietary interaction of phosphorus with sodium from either chloride or bicarbonate affects laying hen performance

Experimental diets consisting of two levels of total phosphorus (.30 and .75%) and three different treatments of supplemental sodium (.35% NaCl, 1.40% NaCl, and .35% NaCl plus 1.50% NaHCO3) were fed in a 2 X 3 factorial arrangement to laying hens for 16 weeks. The latter two treatments of sodium were designed to supply the same level of sodium (.55%) from different chemical forms. Hens fed .30% phosphorus laid significantly (P less than .01) less eggs than those fed .75% phosphorus. A highly significant (P less than .01) interaction was found between phosphorus and sodium treatments. The high level of sodium from either chloride or bicarbonate decreased egg production at the lower level of phosphorus and increased it when the higher level of phosphorus was fed. Sodium bicarbonate affected egg production more strongly than sodium chloride did. There were no significant treatment effects on egg weight and egg shell weight. Addition of sodium bicarbonate to the low phosphorus diet significantly (P less than .05) decreased feed consumption of the hen. Supplemental sodium bicarbonate with either level of dietary phosphorus significantly (P less than .05) increased percent nitrogen retention of the hen, but excessive sodium chloride did not.

Morphine in lymph nodes of heroin users

During the autopsy of heroin users, the most consistent morphologic finding is the enlargement of hepatic lymph nodes. Nodes from seven heroin addicts were analyzed for morphine and a concentration range of 0.02 to 0.87 mg/100 g was found. Morphine was detected in all of the nodes examined and the concentration was generally higher than that in the blood.

The phosphorus excretion pattern and balance during one egg cycle of the laying hen fed a phosphorus deficient diet with or without a single dose of phosphoric acid

A balance trial was conducted to study the phosphorus excretion pattern of laying hens in relation to egg cycle. Excreta were collected quantitatively at 4, 8, 12, and 24 hr after oviposition. The amount of feed consumed corresponding to the excreta collected at a specific time interval was calculated using chromic oxide as a marker. The percent recovery of chromic oxide with laying hens was 73.97 +/- .56%. The maximum apparent digestibility of the dietary phosphorus, all of plant origin, was estimated to be 28.9 +/- 3.1% during 0 to 4 hr after oviposition when the endogenous excretion of phosphorus was theoretically minimized. Laying hens fed a diet containing .30% phosphorus excreted 24.3 mg less phosphorus than intake during the day, indicating that hens had to withdraw approximately 100 mg of phosphorus from their body to produce an egg. These hens excreted 63.1 +/- 27.0 mg of endogenous phosphorus during the 24 hr period, most of which was excreted during the period between 12 to 24 hr after oviposition of the previous egg. The excretion pattern of phosphorus was closely related to the egg laying cycle of the hen. Hens dosed with 100 mg of phosphorus, as a phosphoric acid solution, excreted more phosphorus than the undosed control birds. Approximately 45 mg of 100 mg of the phosphorus dose were excreted during the 24 hr period. At least 84.8 mg of the dosed phosphorus were absorbed within 12 hr and a part of it was excreted during the later period. Data indicated that the true absorption rate of the dosed phosphorus might have been much faster.

Blood phosphorus levels of laying hens at various time intervals after dosing with phosphoric acid

Two experiments were conducted to study the pattern of change in serum inorganic phosphorus level in laying hens fed a diet containing 0.30% total phosphorus after dosing with a known amount of phosphorus. Serum phosphorus level of undosed hens was 2.5 mg/100 ml at oviposition in both experiments. After dosing with 100 mg of phosphorus in 10 ml of a phosphoric acid solution, serum phosphorus level increased sharply and reached a peak of about 7.0 mg/100 ml between 30 and 60 minutes in experiment 2. After the peak the elevated level of serum phosphorus decreased logarithmically until 5 to 6 hours after dosing and eventually decreased to 2.5 mg/100 ml which was the serum phosphorus level of undosed hens in experiment 1. The half-life of the elevated portion of serum phosphorus due to the dosing was about 100 minutes.

Effects of different short-term dietary phosphorus levels on egg specific gravity and blood phosphorus of hens

In the first 2 experiments, laying hens were fed a diet containing .30% phosphorus for a preliminary period of 3 days. At the beginning of the experimental period, hens were fed .30, .75, or 1.40% phosphorus with 3.50% calcium. Another group of hens was fed .75% phosphorus and 1.40% calcium. Specific gravity of the eggs and blood serum inorganic phosphorus were determined and compared with those from control hens continuously fed a diet containing .75% phosphorus and 3.50% calcium. Both high phosphorus and/or low calcium decreased the specific gravity of eggs and increased the serum phosphorus level. In experiment 2, hens were fed different levels of phosphorus at different times of the day. Birds receiving 1.40% phosphorus between 0700 and 0930 hr and .30% phosphorus between 0930 and 2000 hr (Treatment 2) laid eggs with higher specific gravity than hens fed .30% phosphorus between 0700 and 0930 hr and 1.40% phosphorus between 0930 and 2000 hr (Treatment 3). there was no further improvement in egg shell quality over that from hens fed .75% phosphorus for both time periods (0700 to 2000 hr). In both experiments it was apparent that the dietary phosphorus level affected egg shell quality.

The effects of antihypertensive serum in rats with adrenal regeneration hypertension

An antiserum was produced against the plasma of rats with adrenal regeneration hypertension. When the antiserum was adsorbed with normal rat plasma a single precipitin arc in the pre-albumin zone remained in the antiserum, indicating a specific antibody against the hypertensive factors responsible for this type of hypertension in rats. Following a single injection of the adsorbed antiserum into rats with adrenal regeneration hypertension, the level of blood pressure dropped noticeably. Histologically, the zona glomerulosa of hypertensive rats was hyperplastic, whereas that of rats receiving the antiserum showed marked atrophy.