Tissue Nutrition Research Articles

Autoplasty of post-resection defects of long bones in modern treatment of osteogenic sarcoma in children

High survival rate obtained in the treatment of osteogenic sarcoma resulted in substitution of organ-removing operations to organ-saving ones. Methods of total joint replacement used in adult practice can not be so widely applied in paediatric practice due to incompleteness of skeleton growth in children. The solution of the problem is the methods of autoplasty using the fibula including free transplantation, transposition of fibula with nutritional tissue mass and plasty by vascularized graft. Fibula autoplasty is efficient in application with the complex of antineoplastic chemotherapy and postoperative management of patients as well as the treatment of possible complications. This is confirmed by the data of examination of 91 patients with osteogenic sarcoma, aged 415, who were treated at Oncology Department of the Russian Paediatric Clinical Hospital in the period from 1987 to 1998.

Characterisation of Aceria massalongoi and a histopathological study of the leaf galls induced on chaste trees.

The eriophyoid mite Aceria massalongoi (Canestrini) was collected from globoid leaf galls on severely injured chaste trees, Vitex agnus-castus L. (Lamiaceae), in Bari and Bernalda (southern Italy), and on the Ionian island Leukade (Greece). Female, male and nymph were described in detail, following the current morphometric descriptive scheme, supplementing older and incomplete descriptions. Molecular characterization of A. massalongoi from Italy and Greece was conducted by amplifying and sequencing the ribosomal ITS, the D2-D3 expansion domains of the 28S rRNA gene and the mitochondrial COI, for the first time. Phylogenetic trees based on the three molecular markers showed congruent results, confirming that Italian and Greek A. massalongoi populations are the same species that cluster together with some intraspecific variability. Galls, ranging from 0.5 to 2.8mm in diameter, were randomly distributed on both leaf surfaces, and protruded ca. 1mm from the leaf surface. Sometimes they were closely aggregated on midrib and leaves, which, consequently, appeared strongly deformed. Close-up observations revealed that gall induction causes hyperplastic proliferation of leaf tissues around the gall chamber hosting mites. The uniserial cell lining inside this chamber provides the nutritional tissue for the mites. All feeding cells contained one or more (frequently 2-3) hypertrophied nuclei and dense granular cytoplasm.

Change in fatty acid composition and evaluation of lipids and protein oxidation in the commercial cooked clams (<em>Ruditapes decussatus</em>)

This study aimed to provide information about the changes in fatty acid composition and quality in Ruditapes decussatus tissue after four culinary treatments (steamed, baked, grilled and fried). All treated samples showed a significant decrease in moisture and protein. In contrast, a significant increase in fat content resulted from the grilled and fried treatments. Saturated fatty acid was significantly higher in fresh clams than all cooking processes, except in fried ones. Monounsaturated fatty acid and polyunsaturated fatty acid varied significantly between fresh and cooked clams with high values recorded for fried clams. The n-3/n-6 ratio, peroxide index, EPA+DHA and atherogenicity index decreased significantly after the cooking processes particularly in fried clams. The mineral levels (Mg, Ca and Mn) of cooked clams decreased considerably with grilled and fried treatments. The impacts of cooking on the fatty acid composition and protein content in clam tissue was evaluated by lipid peroxidation (TBARS, PV, FFA, TOR) and protein oxidation (AOPP and PCO), which varied statistically in fried, steamed, grilled and baked samples; indicating alterations in cooked clam tissues structure. Based on our results, steaming is recommended for the preparation of clams because it preserves the most nutritional tissue quality.

The Effect of Diet on Ovarian Development and Nutritional Tissue Composition of Portunus trituberculatus

This study investigated the effects of feeding trash fish (TF), formulated diet (FD), and mixed diets (MD) on ovarian development, fattening performance, and nutritional quality of P. trituberculatus. Formulated diet treatment resulted in lower gonadosomatic index, hepatosomatic index, meat yield, and total edible yield than the other treatments. It also showed lower protein (7.88%), lipid, and ash content in hepatopancreas and muscle, compared to the other treatments. Different diets significantly affected the contents of C16:0, C18:1n9, C18:2n6, C18:3n3 and C20:5n3 of hepatopancreas. FD treatment resulted in lower essential amino acids and non-essential amino acid contents in the muscle compared to TF and MD treatments. The highest and the lowest essential amino acids scores were found in the TF and FD treatments, respectively. In conclusion, these results indicated that FD is not suitable and requires further development for sub-adult crabs, while MD would be the recommended for fattening female P. trituberculatus.

A guided tour: Pollen tube orientation in flowering plants

Sexual reproduction in flowering plants requires that two sperm cells are delivered to the embryo sac where double fertilization of an egg cell and of a central cell results in the formation of a diploid embryo and of the triploid nutritional endosperm tissue. The immobile male gametes are delivered to the immobile female gametophyte by a single cell, the pollen tube. The pollen tube must be able to germinate on a genetically appropriate stigma and it must be directed through the transmitting tract of the style from where it must target an ovule. Moreover, the pollen tube must enter the ovule at a defined opening, the micropyle, grow toward one of the two synergids and release the two sperm cells upon contact. This complex process requires recognition events with chemically based or physically supported cell-cell communication as well as directional cues for the growing pollen tube. A number of molecules and mechanisms have been implicated in pollen tube guidance which are summarized in this review.

Roundtable conference on tissue oxygenation in acute medicine, Brussels, Belgium, 14-16 March 1998.

* Nutritional tissue perfusion and tissue metabolic demand are heterogeneously distributed. * Oxygen diffusion occurs preferentially at the precapillary arteriolar level. * Determination of adequacy of tissue oxygenation requires local organ measurements. * While there remains considerable variability in individual RBC transfusion practices, a recent clinical trial questioned the efficacy of RBC transfusion to hemoglobin concentrations greater than 80 gm/l in patients without heart disease [63]. * RBC substitutes, including cell-free hemoglobin solutions and PFC solutions are efficacious, yet may exhibit a number of direct vascular effects.

Reproductive Cycles of the Ascidians Microcosmus sabatieri and Halocynthia papillosa in the Northwestern Mediterranean

Abstract. The reproductive cycles of Microcosmus sabatieri Roule and Halocynthia papillosa (Linnaeus) (Ascidiacea, Pyuridae) were investigated by means of histological observations of the gonads and gonad index measurements on monthly samples from Northeast Spanish coast populations during 1985. Both species are simultaneous hermaphrodites, and the spawning season lasts for two to three months ‐ between September and November ‐ after the period of highest water‐temperatures in the area. The evolution of the gonads during the whole cycle is markedly different in both species. Spawning time is extended towards summer in H. papillosa and towards winter in M. sabatieri.SummaryThe parameters studied in H. papillosa and M. sabatieri indicate a single spawning season per year in the area studied. Both species are simultaneous hermaphrodites, and gamete release occurred after the period of highest seawater temperatures, with a maximum in September‐October for H. papillosa and in October‐November for M. sabatieri. Moreover, the release is noticeably more rapid in H. papillosa.Mean oocyte diameter and gonad index show a good correlation. The values of the latter were almost twice as high in H. papillosa than in M. sabatieri. Since no development of nutritional tissue has been observed in histological sections, this can reasonably be interpreted as a higher investment in gamete production in H. papillosa.Rapid buildup of the gonad, gradual release of gametes, and low gonad indices occur in M. sabatieri, whereas gradual buildup, rapid release, and higher gonad indices are displayed by H. papillosa. This indicates different reproductive behavior in these species, a conclusion which is confirmed by statistical analyses.

Very-Low-Calorie Diets

To the Editor.— A recent commentary by Wadden et al1on the irresponsible use of very-low-calorie diets hints at the possibility of yet another epidemic of sudden cardiac death among the obese and desperate. In this light, it should be noted that research has yet to explain adequately the appearance of prolonged QT intervals or malignant ventricular arrhythmias in patients who undergo rapid and substantial weight loss. Sours et al2found that supplemented fasting deaths could not be explained by such factors as the quality or quantity of medical care, the biologic quality of the protein supplement, or electrolyte balance as determined by potassium intake. More recent research has challenged the assumption that nutritional depletion or lean tissue loss precipitated these deaths.3,4These studies suggest that a portion of the obese population is at increased risk of developing malignant arrhythmias in response to stress, regardless of the

Influences on central hemodynamics in hemorrhage of beta 2-adrenergic vascular control mechanisms.

Central hemodynamic responses evoked by standardized hemorrhage (exsanguination of 20 ml x kg bwt-1) were followed during 2 h in cats with intact and blocked vascular beta 2-adrenoceptors using the 'selective' beta 2-blocker, ICI 118, 551. In the first 10 min after bleeding blood pressure and cardiac output (CO) decreased and total peripheral resistance (TPR) increased by the same amount in the 'intact' and beta 2-blocked animals. Whereas blood pressure later on reached approximately the same hypotension level in both groups, other hemodynamic variables were distinctly different. In the 'intact' animals there was a gradual, partial recovery of stroke volume (SV) and CO in the face of a restoration to control of TPR. In the beta 2-blocked animals TPR continued to increase in the face of a maintained low CO and declining SV. The lower SV in the latter group was ascribed to abolition of beta 2-adrenergic restoration of plasma volume via absorption of tissue fluid into the circulation. The gradual decline of TPR in the 'intact' animals was attributed to beta 2-adrenergic dilator interaction with constrictor influences on the resistance vessels. It is concluded that beta-adrenergic vascular control mechanisms help to improve nutritional tissue blood flow during hemorrhage by increasing plasma volume, and hence venous return and CO, and by decreasing TPR. These reflex, beta 2-adrenergic circulatory events are similar to those aimed at in current shock therapy by transfusion and vasodilator treatment.

Dextran and the Prevention of Postoperative Thromboembolic Complications

1. The purpose of fluid administration is not only the restoration of blood volume but also the normalization of impaired nutritive flow. 2. Plasma oncotic (colloid osmotic) pressure is the only force which can draw water into the circulation. In shock the infusion of colloid solutions is able to normalize nutritive flow and peripheral resistance almost at once. 3. Five per cent solutions of pasteurized plasma protein or albumin and 6 per cent dextran 70 yield a volume expansion corresponding to the amount infused. 4. The decrease in hematocrit produced by the infusion of these three colloidal solutions is accompanied by a decrease in whole blood viscosity resulting in a rise in cardiac output as well as in nutritional tissue flow. 5. Hemodilution improves oxygen supply as long as the hematocrit does not fall below 30 per cent, although normovolemia is the critical requirement. 6. Transmission of viral hepatitis is still the greatest danger of blood transfusion. 7. The use of large amounts of Ringer's lactate is not advised, as this solution does not reduce the total number of units of blood which need to be given. Pulmonary edema may become a problem. 8. Dextrans are best suited to initial volume replacement in shock. They increase plasma volume, improve blood flow, have antithrombotic properties, and are easily available and relatively cheap. Anaphylactoid reactions are rare. 9. Every third patient undergoing general surgery and every other patient having hip surgery develops a deep venous thrombosis. Widespread prophylaxis to prevent thromboembolic complications is mandatory. 10. The antithrombotic properties of dextran are due to a reduction in platelet adhesiveness, a change in fibrin clot structure, and the increased lysability of thrombi and the improvement of blood flow. 11. In a personal controlled, prospective, randomezed trial comparing subcutaneous heparin and intravenous dextran 40, 35.8 per cent of the controls (n=95), 13.2 per cent of the 83 patients in the heparin group, and 20.5 per cent in the dextran group (n=83) developed deep venous thrombosis. The difference between dextran and heparin is not significant; however, both treatment groups show a statistically significant effect compared to the controls.