Meckel the Younger and his epistemology of organic form: Morphology in the pre-Gegenbaurian age

Summary The goal of our paper is to investigate Meckel’s epistemology of organic form, based on study of his original publications. Johann Friedrich Meckel the Younger (1781–1833) was one of the leading figures of German morphology in the early 19th century. Historiographic studies on morphology in this time period show, that biological research was largely preoccupied with questions about the relationship between form and function. Investigations into Meckel’s epistemology of organic form can contribute to our understanding of the development of morphology in the pre-Gegenbaurian age.     

Protein Turnover in Brain of the Rat Fetus

Protein synthesis in vivo was studied in whole brain of rat fetuses using continuous intravenous infusion of L-[U-14C]tyrosine into unrestrained pregnant rats at 19 and 21 days gestation. Protein degradation (KD) was calculated by subtracting fractional growth rate of brain protein (KG) from the fractional synthesis rate (KS). KS was high at both gestational ages (0.42 +/- 0.03 days-1 at day 19, 0.47 +/- 0.029 days-1 at 21 days), comparable to values previously reported for newborn rat cerebral hemispheres, and threefold higher than is seen in adult animals. KD was similar at both 19 and 21 days gestation (0.19-0.24) and lower than that reported in neonatal rat brain using similar techniques. Protein accretion during the most rapid phase of brain growth (fetus) is accomplished by similar rates of protein synthesis, but decreased rates of degradation when compared with a slower growth phase (newborn). KD in the brain of the rapidly growing fetus is slightly higher than in adult cerebral hemispheres.     

Observations of a set of isomeric anti-lactose antibodies directed against a group D streptococcal polysaccharide

Sets of isomeric anti-lactose antibodies with specificity for the lactose units of a cell wall polysaccharide fromStreptococcus faecalis strain N were induced in rabbits immunized with a vaccine of nonviable cells of the organism. Such sets of anti-lactose antibodies were isolated from the serum of immunized animals by affinity chromatography on lactosyl-Sepharose. Gel electrofocusing experiments showed that the preparations consisted of multiprotein components. One preparation of antibodies of 13 isomers was separated into homogeneous components by liquid isoelectrofocusing. The individual isomeric antibodies exhibit specificity for the lactose units of the antigenic polysaccharide, possess isoelectric points in the range of 5.9–8.0, and belong to the IgG class of immunoglobulins, and each member yields one light chain and one heavy chain on dissociation in sodium dodecyl sulfate (SDS) and mercaptoethanol. These results have been interpreted as evidence for the assembly of the chains of isomeric antibodies by a single-chain pairing mechanism.     

Species novae generisEremostachys (Labiatae)

Five new species are described:Eremostachys codonocalyx from NE. Iran (related toE. subspicata),E. stenocalycina from NE. Afghanistan (related toE. alberti andE. hissarica),E. salangensis from NE. Afghanistan (close toE. bamianica),E. freitagii from E. Afghanistan (similar but not closely related toE. vulnerans), andE. andersii from E. Afghanistan (similar but not closely related toE. vulnerans), andE. andersii from NE. Afghanistan of isolated systematic position.

Florae Iranicae praecursores 5–9.     

Insulin-Like Growth Factor I Receptor Binding in Brains of Alzheimer''s and Alcoholic Patients

Patients with chronic alcoholism and/or Alzheimer's disease show degenerative changes in the cerebral cortex and hippocampus. To investigate possible changes in insulin-like growth factor I receptor binding sites in brain tissue of patients with these pathological conditions, the number of 125I-insulin-like growth factor I binding sites was determined in tissues obtained from control patients and those with Alzheimer's and/or with a history of alcoholism. The four experimental groups examined consisted of patients from similar age groups. Postmortem histology and a clinical history were used for the diagnosis of Alzheimer's disease and alcoholism, respectively. Careful clinical records were kept concerning other variables such as immediate cause of death and medications administered before death. Specific binding of 125I-insulin-like growth factor I to homogenates prepared from cerebral cortex of Alzheimer's, alcoholic, alcoholic Alzheimer's, and age-matched control patients was similar, although Alzheimer's patients tended to have slightly higher binding values. No significant differences in insulin-like growth factor I binding in cerebral cortex were found with regard to age of patients, the interval between death and autopsy, and CNS-active medications. No statistical differences in 125I-insulin-like growth factor I binding were noted in hippocampal tissue from the four patient groups. Thus, human insulin-like growth factor I binding sites in cerebral cortex and hippocampus appear unaffected by several variables.     

Factors controlling embryonic heart cell proliferation in serum-free synthetic media

Summary Embryonic chick cardiac cell cultures, plated on collagen-coated dishes, containing serum-free synthetic media proliferate actively. The basic medium contained Ham's F12 nutrient mixture, fetuin, ascorbic acid, and bovine serum albumin. This medium was supplemented with various combinations of factors; endothelial cell growth supplement (ECGS), epidermal growth factor (EGF), insulin (I), transferrin (T), selenium (S), hydrocortisone, and thyroxine or supplemented alone. Basic medium supplemented with ECGS alone contributes to the highest final cell density among all other factors used in various combinations or alone. The final cell density of the control culture with 2% fetal bovine serum was higher than those of all experimental cultures and an additional control culture grown in the basic medium. Combinations of factors without ECGS do not promote significant cell proliferation. Thyroxine is required to induce optimal differentiation and contractility of cardiac myocytes in vitro. Fibronectin and laminin did not show any more influence than collagen did on the growth and maintenance of cardiac myocytes in serum-free media. The proportion of cardiac muscle cells in ECGS-containing media was higher than those in other experimental media and control media with the exception of ECGS and ITS-containing medium that showed lower proportion of cardiac myocytes than that of serum-containing medium on Days 3 and 5. The profiles of incorporation of [³H]thymidine into DNA of heart cells in experimental and control cultures showed a peak in incorporation values within the first week of culture and subsequently declined. Autoradiography studies revealed that cardiac myocytes in culture supplemented with ECGS alone attained a peak in labeling index on Day 1 with approximately 62% labeled cells. Subsequently, the labeling indices declined. Cardiac myocytes grown in media without ECGS showed significantly lower labeling indices than those in ECGS-containing media. This study has demonstrated the influence of ECGS, EGF and ITS in promoting the growth of cardiac myocytes and also in contributing to the maintenance of contractile cardiac myocytes in serum-free, long-term culture. The influence of ECGS on heart cell proliferation is considered to be superior to that of EGF and ITS. This study was supported in part by a grant HL-25482 from the National Heart Lung and Blood Institute and a grant from the American Heart Association of Michigan.     

High temperature and oxygen supplementation can mitigate the effects of hypoxia on developmental stability of bilateral traits during incubation of broiler breeder eggs

Hypoxia strongly affects embryonic development during the pre-hatch period. This study was conducted to investigate the effects of oxygen supplementation (O) and a 38.5°C high temperature (HT) at high altitude (HA, 1720 m) on morphological traits during a pre-hatch period and on relative fluctuating asymmetry (relative FA) and allometric growth during an early post-hatch period in broilers. A total of 720 eggs were obtained from a 45-week-old Ross 308 broiler breeder flock raised at sea level (2 m). The eggs were divided into six incubation condition (IC) groups and were incubated at HA. O groups were exposed to 23.5% O₂ for 1 h daily from either days 0 to 11 (O_0–11), days 12 to 21 (O_12–21) or days 18 to 21 (O_18–21) of incubation. HT groups were exposed to 38.5°C daily from either days 12 to 21 (HT_12–21) or days 18 to 21 (HT_18–21) of incubation. A control was maintained at 37.8°C and 21% O₂. The hatched chicks were raised for 6 days at HA. Embryo/chick and beak lengths and head diameter were measured during pre- and post-hatch periods. The face, middle toe and shank lengths were measured for each chick. The relative asymmetry (RA), mean RA (MRA) and allometric growth of the lengths were computed and the existence of FA was demonstrated. The IC significantly affected the embryo length, with embryos of the O_0–11 group shorter than embryos of the other O groups. Chicks were longer in the O and HT groups than those in the control, except for the O_0–11. We found significant interactions between the IC and each development period for beak length. During the post-hatch period, the head diameter of the O_0-11 was significantly smaller than that of the other groups, but not in O_12–21. The interactions among IC, age and sex were significant for the RA of the face and middle toe lengths and for MRA. All the examined bilateral traits were evaluated as allometric growth. The FA for bilateral traits was determined in both sexes. The right (R) – left (L) and IR-Ll were the lowest in females for face length and in males for shank length from the O_18–21 and in males for middle toe length from the O_0–11 and HT_18–21 groups. Therefore, the effects of factors such as HT and O₂ could mitigate the adverse effects of HA-induced hypoxia on optimal developmental stability of bilateral traits of broiler.     

Purine nucleoside phosphorylase (Np) in the mouse: Linkage relationship of Np-2 to esterase-10 (Es-10) and Np-1 on chromosome 14

An improved method for detecting four Np-1 (purine nucleoside phosphorylase) alleles in mouse erythrocytes by cellulose acetate electrophoresis is described. The previous linkage of Np-1 and Es-10 (esterase-10) was confirmed, with a map distance of 13.0±2.6 cM. Np-2 was detected by either specific activity assay or starch gel electrophoresis and shown to be linked to Es-10, 15.9 ± 3.1 cM, on chromosome 14. No recombinants between Np-1 and Np-2 were observed in 52 offspring, indicating either that these loci are either closely associated or that Np-2 represents simply a property of existing allelic products of the Np-1 locus.This research was supported by Medical Research Council of Canada grants to F.G.B. and F.F.S.     

Oecophylla smaragdina food conversion efficiency: prospects for ant farming

Oecophylla ants are sold at high prices on several commercial markets as a human delicacy, as pet food or as traditional medicine. Currently markets are supplied by ants collected from the wild; however, an increasing interest in ant farming exists as all harvest is easily sold and as ant farming can be combined with the use of the ants in biological control programmes in tropical plantations where pest insects are converted into ant biomass. To assess the cost‐benefits of ant farming based on artificial feeding, food consumption and food conversion efficiency (ECI) of Oecophylla smaragdina (Fabricius) was tested under laboratory conditions. Of the two types of food offered, the ants ingested 76% pure sucrose and 24% insect prey (dry weights) leading to ECI’s of 29% and 39% including brood only or brood plus imago gain, respectively. Based on Thai sugar and protein food costs and ant brood selling prices these efficiencies led to rates of return from 1.52 to 4.56, respectively, if: (i) protein is supplied from commercial products; or (ii) alternatively supplied from free sources such as insects and kitchen waste. These results suggest that Oecophylla ant farming may become highly profitable and deserves further research.