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A new structure-affinity model for the aromatic hydrocarbon (Ah) receptor is reported. The proposed mathematical model completely eliminates multiple regression analysis in its formulation and overcomes the cross-class comparison inherent to classical quantitative structure-activity relationships. Taking the polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) as model xenobiotics, the binding affinity of a PCDD relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is shown to be analytically related to the electron affinities, entropies, and lipophilicities of PCDD and TCDD. From the calculated dissociation constants of PCDD-Ah receptor complexes, the corresponding equilibrium constants of PCDF-Ah complexes could be computed, in agreement with the experimental observation that the trend in the binding affinities of PCDDs and PCDFs to the Ah receptor are similar. The reported model is capable of quantitatively explaining the quantitatively estimating the in vitro binding affinities of PCDDs, PCDFs, and related xenobiotics to the Ah receptor. Therefore, a halogenated aromatic compound is expected to have a higher affinity for the cytosolic protein than TCDD if it is less lipophilic and has a higher electron affinity and lower entropy. Furthermore, the affinities of structurally related polychlorinated aromatic xenobiotics for the Ah receptor could be computed from their entropies and electron affinities.

The response of adult rats fed diets containing amino acid mixtures with varying combinations of lysine and threonine was studied by estimating the change in body weights, organ weights, total nitrogen content of organs and the concentration of free plasma lysine and threonine. Analysis of variance indicates a significant effect of threonine, lysine and a significant interaction due to feeding the two amino acids on the body weights, organ weights and total nitrogen content of various organs. Significant effect on the level of the plasma free amino acid was also shown as a result of feeding the particular amino acid. Results show that in deficient animals the rates of building body protein are low but are higher in the lysine deficient animals than in the threonine deficient and protein deficient animals. The varying rates of exchanging protein between the various organs in response to changing the levels of amino acids in the diet would mean that total change in body protein or total nitrogen balance may not be satisfactory way to determine the protein or amino acid requirements for maintenance. It seems to be necessary to focus down on protein turnover rates in specific tissues.

The mechanism of suberoylanilide hydroxamic acid in cell growth inhibition involved induction of pRb-2/p130 interaction and nuclear translocation with E2F-4, followed by significant repression in E2F-1 and PCNA nuclear levels, which led to inhibition in DNA synthesis in mammary epithelial cell lines.

The protein quality of two common Egyptian meals namely lentils and “Koshari” was evaluated on rats by utilizing the net protein ratio (NPR), the relative protein value (RPV) and the serum urea content methods. Casein was used as a reference protein. The macro nutrient contents of the two meals are almost similar. The NPR is higher with low dietary protein level. The estimated RNV of the “Koshari” was higher than that of lentils. Lower serum urea levels were found with the “Koshari” than with lentils meal indicating its better protein quality. This is most probably due to the effect of amino acid supplementation of cereals and legumes. Results obtained are in favour of utilizing the serum urea content method as a simple and reliable one for evaluating protein quality since a negative relationship exists between blood urea content and the biological value of dietary protein. Its validity in estimating dietary protein quality in man need to be investigated.

By adding a small number of demographic and family planning questions to a nutrition status survey a great deal of data useful for family planning programs can be generated. Information can be available on the prevalence of contraception variation in contraceptive use and source as well as method of contraception soon after the completion of field work and at little cost to the program. In addition a survey containing both data on nutrition status of children and on contraceptive use of mothers has the potential for studying the links between family planning use and child health which are strong according to a review of literature. In the 1978 Arab Republic of Egypt Nutrition Status Survey which between December 1977 and April 1978 sampled lower-status urban and rural women throughout Egypt about 1 in 5 mothers interviewed were found to be contraceptive users. Rural areas showed a 11.7% contraceptive prevalence among women; small urban areas 15.5% and large urban places 50.6%. Oral contraceptives were the most prevalent (84.2% overall) followed by IUDs (8.7%) and condoms (1.6%). 41.5% of users acquired contraceptives from a government maternal and child health clinic 38.0% from private pharmacies 10.4% from other government clinics. A positive association was found between current contraceptive use and the measures of child health (height hemoglobin levels) an association that was maintained when residence social status and other background variables were controlled statistically.

The protein value of meat soy blend was evaluated by utilizing the net protein ratio (NPR), the relative protein value (RPV) and the serum urea content methods. It was compared with that of meat. Casein was used as a reference protein. NPR values indicated that utilization of meat and meat soy proteins are comparable. The study of amino acid pattern shows that sulphur containing amino acids are limiting to almost the same degree in meat and meat soy blend. However, the RPV of meat soy bean blend is slightly higher than that of meat. The lowest serum urea content was that of rats fed meat soy blend. Therefore, the mixing of meat with soy bean did not reduce the nutritive value of meat, on the contrary there is tendency towards improvement.

Birthweight surveillance is an important epidemiologic tool yet it is largely unattainable in locales where most births occur at home attended by traditional midwives. A tempered steel handheld scale developed by the program for Appropriate Technology in Health (Seattle Washington) was adapted for use by Egyptian traditional midwives; it identified newborns weighing

The nutritional quality of edible portions from certain kinds of pigeons that exist in Egypt was studied by determining their biochemical composition and by biological evaluation. Pigeon meats are in general fatty. They have a high energy value and contain all essential amino acids in amounts and proportions required by the human body. They are excellent sources for vitamins and minerals particularly B1, B2, calcium, phosphorus and iron. The nutritive value of pigeon proteins is rather good. No significant differences were encountered due to variations of type or sex.

The theory of hypergames is used to retrospectively analyse actions taken during the period of crisis immediately prior to the 1973 Arab-Israeli war. The analysis supports the hypothesis that each player behaved rationally within the framework of his own perceptual game, actions corresponding to stable outcomes in the axis of the game. A proposed methodology is put forward for applying the theory to current crisis problems.

The protein quality of broad beans was evaluated by using three different methods: the net protein ratio (NPR), the net protein utilization (NPU) and the relative protein value (RPV). Casein was used as a reference protein. The relationship between the values obtained on rats by each method and serum urea concentrations were examined. Serum urea concentration increased by increasing the dietary protein content. It showed a positive correlation of 0.70 and 0.60 for broad beans and casein respectively. NPR values increased by decreasing the level of dietary protein. There was no relationship between the NPR and the serum urea contents in animals fed the casein and broad bean diets. The NPU values indicated that protein utilization was greatest at low dietary protein levels and decreases by increasing the protein content of diet. Serum urea concentration showed an inverse proportion with the NPU values. This was demonstrated by correlations of -0.67 and -0.75 for broad beans and casein respectively. The highest RPV for broad beans was obtained by using the change in body water and the lowest by using the change in body nitrogen as a response parameter. An inverse relationship exists between serum urea concentration and the RPV for broad beans.

Lysine availability in wheat four and bread was determined by the growth response method on rats using regression analysis relating gain in body weight and/or in body watch to lysine consumed at two extractions, 87% und 72%. The availability of nitrogen and of essential amino acids were also determined by the balance trials method (fecal analysis method) with rats. The results of growth method show that baking increases lysine availability on the basis of body water gain. Also extraction levels affect lysine availability on the basis of change in body water. Wheat flour and bread of 72 % extraction has more lysine availability values than the 87 % extraction on the basis of moisture gain. Results of balance trials show that neither the extraction level nor the baking has a significant effect on essential amino acids availability. A fairly good correlation is obtained for wheat flour and bread for the two extractions. Values of change in weight, food efficiency, PER, NPR and true digestibility showed that baking and level of extraction of wheat has no significant effect on the nutritive value of wheat investigated in the present study.

Attempts were made to prepare 5 protein rich food mixtures to be used as supplementary and weaning foods for children from 6 months of age onwards. They contain vegetable and animal protein sources. They were prepared in a way to simplify their use. Potatoes, carrots and peas were the basal ingredients in each mixture. The protein content of the mixtures ranges from 16-20 % with a chemical score not less than 50 %. The mixtures contained most of the essential amino acids in optimal concentrations, except methionine and cystine which are slightly lower than the amounts recommended by FAO. The nutritive value of each mixture estimated by the slope ratio bioassay procedure was high. They are nutritionally superior to casein, used as a reference protein. They differ slightly when compared with each other.

Five different brands of instant dry whole milk that are most commonly used, and freeze dried milk were analyzed for nitrogen, fat, ash and 4 inorganic constituents and compared with human milk. The composition of the milks differed considerably. The protein content varied widely, ranging from 11.6 to 24.5%. Fat content did not differ widely, ranging from 24.9 to 29.5%. Freeze dried milk had the highest fat content (42.6%). Three out of the five brands of dry milk studied were spray dried and the remaining two were roller dried. All milks tested contained considerably more sodium, potassium, calcium and phosphorus solid than human milk, some of them the four fold amount of calcium and phosphorus.

Five different brands of dry milk and freeze dried milk were used in rat feeding trials to study their nutritive value and to assess the effect of the drying process on their nutritive value by using growth response, weight gain, food efficiency and relative nutritive value (RNV). Brand I milk gave better growth response, weight gain and food efficiency than any other dry milk studied, while brand V gave the least values. Freeze dried milk gave better growth response, weight gain and food efficiency than brand I milk. Using Slope-ratio assay, freeze dried milk gave the best RNV compared to all dry milks tested on the basis of the two response parameters used, weight gain and moisture gain.

The protein quality of two common Egyptian meals namely lentils and "Koshari" was evaluated on rats by utilizing the net protein ratio (NPR), the relative protein value (RPV) and the serum urea content methods. Casein was used as a reference protein. The macro nutrient contents of the two meals are almost similar. The NPR is higher with low dietary protein level. The estimated RNV of the "Koshari" was higher than that of lentils. Lower serum urea levels were found with the "Koshari" than with lentils meal indicating its better protein quality. This is most probably due to the effect of amino acid supplementation of cereals and legumes. Results obtained are in favour of utilizing the serum urea content method as a simple and reliable one for evaluating protein quality since a negative relationship exists between blood urea content and the biological value of dietary protein. Its validity in estimating dietary protein quality in man need to be investigated.

I. Adult rats were fed on diets free of either lysine, methionine, threonine or protein. The threonine- and protein-deficient animals lost weight at approximately the same rate, about IOO g in 14 weeks, at which time several were moribund. In contrast, lysine-deficient animals lost only about 30 g in 14 weeks and had lost only46 g after zz weeks, when they were killed. Methioninedeficient animals showed an intermediate response. Losses in weight of several tissues - kidney, heart and two muscles - were related to, but not necessarily proportional to, the loss of bodyweight. Liver weights relative to body-weights were large in lysine- and threonine-deficient animals and smallest in methionine-deficient animals. 2. Adult rats were fed on diets containing zero, a moderate amount (about twice the estimated minimal requirement) or an excess (about four times the estimated requirement) of lysine or threonine in all combinations (3 x 3 design). Analysis of variance of the body-weights, tissue weights and tissue nitrogen contents indicated, in general, a significant effect of each amino acid, as expected, but also, in most instances, a significant interaction. Plasma concentrations of lysine and threonine were affected by the intakes of the respective amino acids, but plasma lysine concentrations were also affected by the threonine intake. 3. Liver histology also suggestedsignificant interactions between the two amino acids. Animals given no lysine but moderate amounts of threonine developed severely fatty livers; next most severely affected were animals receiving excess of both amino acids. Threonine deficiency, in the presence or absence of lysine, produced moderately fatty livers similar to those seen in protein-deficient animals. 4. Since animals have varying ability to conserve body nitrogen when they are fed on diets limiting in different essential amino acids, mcasuremcnts of biological value (BV) and net protein utilization by conventional methods, over a short period of time, over-estimate nutritive value rclative to amino acid score and probably over-estimate the true nutritive value of poor-quality proteins, particularly those limiting in lysine. If so, this is a serious error, since it leads to underestimates of the protein requirements if BV is used. The fact that certain tissues, particularly the liver, do not necessarily lose nitrogen in proportion to total body nitrogen and may show specific pathological effects depending on the limiting amino acid or the proportions of amino acids in the diet also indicates that general measures of nitrogen economy may not be sufficiently discriminating tests of the nutritive value of proteins. It is abundantly clear that the nutritional quality of dietary proteins is dependent on, if not entirely determined by, the essential amino acid content of the protein. The concept of an amino acid score has been strongly supported by the observation that there is a significant correlation between the calculated score (the adequacy of the most limiting amino acid relative to a protein or amino acid mixture assumed to be ‘ideal’) and observed biological value (BV) or net protein utilization (NPU) (Block & Mitchell, 1946-7; FAO, 1957; WHO, 1965). This concept thus assumes that the nutritional quality of a protein will be compromised to an equal degree by equivalent degrees of deficiency of any essential amino acid or that protein synthesis will be equally impaired by a lack of any essential amino acid.

A national nutrition survey was conducted in Egypt during January-April 1978 in an effort to quantify the protein energy and anemia status of young children from rural and urban areas. Data from 9794 preschool children (8016 in the total representative sample and 1778 in metropolitan Cairo-Giza and Alexandria) were analyzed. Questionnaires on 106 additional children were excluded because of obvious errors in age or anthropometric data. The overall prevalence of wasting was low in all the areas studied. Stunting was identified in 20.8% of the representative sample children. The highest prevalences of stunting occurred in rural villages, small and large, particularly in Upper Egypt (27.0%). Linear growth improved, among the children studied, with increasing urbanization. In cities with a population greater than 50,000 (excluding Cairo and Alexandria), the prevalence of stunting was only 10.6%. The prevalence of stunting was 15.7% and 18.8% in the disadvantaged areas of Alexandria and Cairo-Giza, respectively, and only 1.1% in the special comparison group of 1883 socioeconomically advantaged children. Concurrent wasting and stunting was noted in 0.3% of the representative sample. Children in the 2 age groups between 6-23 months had the highest prevalence of acute undernutrition, and children aged 36-47 months had the highest prevalence of overnutrition. The prevalence of chronic undernutrition was highest in the 3 age groups between 12-47 months and declined approximately 16% in the 2 age groups between 48-71 months. The prevalence of severe malnutrition declined with urbanization from a high of 12.9% in small villages in Upper Egypt to 3.8% in the small cities. Among children in the disadvantaged areas of Alexandria and Cairo-Giza, the prevalences were 4.8% and 9.1%, respectively. For the representative sample, anemia was highest in the 3 age groups between 12-47 months. Of the 9794 children surveyed, 17 had edema in both feet. More than 1 clinical sign of vitamin D deficiency was found in 1.4% of children. Bitot's spots were found in only 4 children and corneal scars in 16.

SummaryThere is abundant evidence that selenomethionine is an analogue of methionine. We have utilized whole-body counting of 75Se after the administration of 75Se-selenomethionine to determine whether this technique might be used to evaluate overall changes in protein metabolism in animals fed different amounts of protein or methionine. Changes in overall body counts were not sensitive to changes in these dietary variables, but the excretion of 75Se was greatly affected by the selenium content of the diet. Thus, whole-body counting is apparently not a useful technique for following the metabolism of tissue proteins.

We present the results of a chromosomal study (C-, Ag-NOR-, endonuclease digestion, DAPI and CMA(3) banding) carried out on four Tunisian species of amphibians: Bufo mauritanicus, B. viridis, Rana saharica and Discoglossus pictus auritus. For comparative purposes, our cytogenetic analysis was also extended to Moroccan specimens of B. mauritanicus and D. pictus scovazzi. Tunisian specimens of B. viridis display chromosome and chromatin characters very similar to those found in other specimens, both North African and Euro-Asian. By contrast, chromosomes of Tunisian specimens of B. mauritanicus differed from the Moroccan specimens in presenting a different Q-banding phenotype. Tunisian specimens of R. saharica displayed the plesiomorphic Pelophylax karyotype of 2n = 26 biarmed chromosomes and NORs on the eleventh pair. The Tunisian specimens of D. pictus auritus; had the typical D. pictus 2n = 28 karyotype with the 13th pair of telocentric elements, in contrast to the Spanish auritus specimens that display the chromosomes of this pair shaped as metacentric. Similarities and differences of the four studied Tunisians anuran taxa are discussed with references to published data on their relatives.

Competing Interests: Declaration of competing interest None.