Chemical and physical methods in dating human skeletal remains

Chemical and physical methods for dating skeletal remains were examined. Benzidine reaction, ultra-violet fluorescence, specific gravity and supersonic conductivity were carried out on 71 dated skeletal findings distributed over the span of the last 3,500 years. Results given by benzidine reaction and ultra-violet fluorescence basically coincide, and positive readings were obtained up to about 200–350 years. Values measured in specific gravity and supersonic conductivity testing show a parallel trend, pointing out a clear difference between samples of the three first centuries and the ones belonging to more ancient periods examined.     

Effects of habitat complexity and predator exclusion on the abundance of juvenile red snapper

Predator exclusion and habitat complexity factors that may affect juvenile red snapper Lutjanus campechanus habitat selection were examined in field and laboratory experiments. A significant predator exclusion effect was detected. Uncaged shell habitats showed significantly lower numbers of age 0 year red snapper, and both uncaged shell and block-shell habitats showed significantly lower numbers of age 1 year red snapper compared with caged habitats ( P < 0·001). Habitat complexity also affected age 0 year red snapper, as mean abundance significantly decreased with decreased habitat complexity ( P < 0·001). In the laboratory, age 0 year red snapper association with complex habitats significantly increased with exposure to a predator Gulf flounder Paralichthys albigutta ( P < 0·001). This study showed that predator exclusion and habitat complexity were significant factors that affected the abundance of juvenile red snapper in nursery areas of the northern Gulf of Mexico. Predation may affect juvenile red snapper abundance directly through mortality and indirectly by influencing habitat selection.     

Lactation-associated redistribution of the glial fibrillary acidic protein within the supraoptic nucleus

Summary Three clones of myeloproliferative virus (MPV)-transformed rat fibroblasts (NRK) with different growth properties and morphology were transplanted to athymic nude mice. Presence of carbohydrate-binding proteins was inferred by fluorescence microscopy using fluorescent, glycosylated markers. Salt and detergent extracts of tumors from this model system were fractionated under identical conditions on different sets of Sepharose columns, to which lactose, asialofetuin, melibiose, mannan and fucose had been covalently linked. Successive elution by chelating reagent and specific sugar resulted in isolation of the different Ca²⁺-dependent and Ca²⁺-independent endogenous carbohydrate-binding proteins that were assayable as agglutinins. In comparison, the different tumors displayed a pattern with qualitative and quantitative alterations. Since protein-carbohydrate interaction mediated by carbohydrate-binding proteins (lectins) is of importance for cognitive processes, it is remarkable that the pattern of membrane glycoproteins, isolated by affinity chromatography on resins with immobilized plant lectins, had also been found to reveal certain individual properties for receptors specific for peanut agglutinin (PNA) and Ulex europaeus agglutinin (UEA). These demonstrated differences within the system of protein-carbohydrate interaction suggest that endogenous lectins and their ligands have potential significance as markers defining a certain phenotype within this tumor model system.Dedicated to Prof. Dr. W. Lamprecht on the occasion of his 60th birthday     

Effect of dopamine agonists or antagonists, TRH, stress and piglet removal on plasma prolactin concentrations in lactating gilts

The effect of dopamine agonists (ergocryptine), antagonists (chlorpromazine, haloperidol, reserpine, pimozide), thyrotropin releasing hormone or stress (restraint, piglet removal) on prolactin release was studied in primiparous lactating gilts. All animals were fitted with surgically implanted jugular catheters before farrowing. The only drug treatments which resulted in a significant change in PRL concentrations in blood were thyrotropin releasing hormone (increase) and ergocryptine (decrease). The results suggest that dopamine may not be the only regulator of prolactin in lactating pigs. Further studies are needed to identify drugs which would be useful in clinical situations for treatment of lactation failure due to low prolactin secretion. In the two stress-exposed groups, there was a gradual, steady decline in the plasma concentration of prolactin which resulted from loss of suckling contact with the piglets. Thus, snare restraint does not increase prolactin secretion in lactating sows confirming the results of other studies on pigs in different physiologic states.     

Butyrophilin,an apical plasma membrane-associated glycoprotein characteristic of lactating mammary glands of diverse species

Lipid globule membranes were isolated from human and bovine milk and from the milk of sheep, goat, pig, rat and guinea pig, and their polypeptide compositions were analyzed. The major polypeptides with molecular weights similar to that of bovine butyrophilin were separated by gel electrophoresis, isolated and characterized with respect to isoelectric point, molecular weight, immunological cross-reactivity and peptide composition after proteolytic cleavage. We show that in all species examined these proteins are similar to bovine butyrophilin in (i) their relative insolubility in buffers of low and high ionic strength and in non-denaturing detergents, (ii) the occurrence of several isoelectric variants, and (iii) patterns of peptides obtained by protease digestion. It is concluded that closely related proteins are major constituents of the cytoplasmic coat structures associated with milk lipid globule membranes of many species, and we propose the name butyrophilins for this group of proteins. Bovine and human butyrophilins are glycosylated with relatively large amounts of glucosamine, mannose, glucose and galactose but little fucose, sialic acids or galactosamine. Most if not all of the sugar residues are associated with an acetone-soluble peptide fragment of $\text{M}{}_{\mathrm{<mtext>r</mtext>}}$ 12 000–16 000 focusing at about pH 4.0. We suggest that this fragment contains a membrane-spanning peptide sequence and is involved in the attachment of the cytoplasmic coat to the membrane of the milk lipid globule.     

Effects of exercise on mammary metabolism in the lactating ewe

Mammary metabolism in multiparous lactating ewes fed either lucerne chaff:barley grain (L:B; 70:30) or lucerne chaff:lupin grain (L:Lu; 70:30) diets was measured while at rest, during exercise on a treadmill at 0.7 m s⁻¹ on a 10 ° slope for 60 min, and during 30 min recovery from exercise. The effects of these treatments on plasma glucose, lactate, alpha-amino nitrogen (-amino N), non-esterified fatty acids (NEFA) and acetate were measured. Net mammary uptake of oxygen and metabolites was calculated from mammary blood flow and arteriovenous concentration (A − V) differences.

Mammary blood flow was reduced by 25% during exercise. Arterial concentrations of oxygen, glucose, lactate, -amino N and NEFA increased during exercise, whereas acetate concentration either remained unchanged or declined. Mammary A − V differences were significantly higher for oxygen, glucose, lactate and NEFA, and tended to be higher for -amino N and lower for acetate during exercise. The mammary uptakes of oxygen, glucose, lactate and -amino N were unaffected by exercise, whereas the uptake of NEFA was significantly increased and that of acetate was significantly reduced. The changes in arterial concentrations and mammary uptakes in response to exercise were not significantly affected by the diet. The responses in acetate and NEFA fluxes across the mammary gland might bring a change in the utilization of other metabolites as well as in the fatty acid composition of milk fat.     

笼养间蜂猴的繁殖

1989年至今,对15只（10,5）成年间蜂猴在人工饲养条件下的繁殖进行观察,结果为：1．间蜂猴的繁殖有明显的季节性;2．发情周期为49．67d(SD=1.25),在此期间,雌性外生殖器红肿,变大;雄性阴囊胀大;3．交配以背腹相贴为主;4．怀孕期为188d;5．哺乳期为108d(SD=4.12);6．均为一胎二仔。     

Prenatal and postnatal transfer of fatty acids from mother to pup in the hooded seal

Unlike most mammals, hooded seal (Cystophora cristata) pups are born with a substantial layer of adipose tissue. Subsequently, during the brief lactation period of only 4 days, fasting mothers mobilize enormous amounts of lipid from blubber and secrete milk (60% fat) at rates of 10 kg·day^-1. Pups gain 7 kg·day^-1 due primarily to the deposition of fat in blubber. We measured blubber content and fatty acid composition of blubber and milk in hooded seal mother-pup pairs at birth and over the 4-day lactation period to examine the nature and source of fetal lipids, the incorporation of maternal blubber fatty acids into milk lipid, and patterns of fatty acid deposition in suckling young. The fatty acid composition of the blubber of the newborn was notably different from that of its mother. Fetal deposition was likely due to a combination of both fetal synthesis and direct placental transfer of maternal circulating fatty acids. The blubber of the newborn was characterized by high levels (>90% of total fatty acids) of saturated and monounsaturated fatty acids of primarily endogenous origin. In particular, the fetus appeared to have high Δ-9 desaturase activity as evidenced by the large amounts of 14:1n-5 (4.2%) and 16:1n-7 (37.0%) in newborn blubber compared to maternal blubber (0.2% and 14.1%, respectively). Nevertheless, essential and long-chain polyunsaturated fatty acids of the n-3 and n-6 families, which could only have originated by direct transfer from the mother, comprised>7% of pup blubber fatty acids and indicated greater rates of placental transfer than found in humans. In hooded seal mothers, rapid lipid transfer during the brief lactation period appeared to be facilitated by direct incorporation of mobilized fatty acids into milk. Although some differences in proportions of specific fatty acids were found between milk and maternal blubber, most of these differences declined over the course of lactation. However, selective mobilization of 20:5n-3 from maternal blubber into milk was apparent throughout lactation and resulted in elevated levels in pup blubber at weaning compared to maternal blubber. Ingested fatty acids were deposited directly and without modification into the blubber of pups, and by 4 days the fatty acid composition of pup blubber was virtually identical to that of the milk consumed.     

Determinants of postnatal weight in infant rhesus monkeys: Implications for the study of interindividual differences in neonatal growth

This paper provides an analysis of infant body weights obtained from a sample of 38 rhesus monkey infants (Macaco mulatta) aged 29–165 days, i.e., animals still nutritionally dependent on their mothers. We examine the data on neonatal weights in relation to a number of factors, most notably, the sex of the infants, and the age and adiposity of their mothers. The infant body weights represent cross-sectional rather than longitudinal data; because they were mostly free-ranging animals, the infants were weighed just once each. Nevertheless, the results of our analysis strongly suggest that early postnatal growth in free-ranging rhesus is dependent on both maternal fatness and age. They also suggest that, although male infants are generally heavier than like-aged female infants, they do not grow any faster during the early postnatal period. Here, we speculate that the associations between infant size and both maternal age and adiposity are the result of between-mother differences in lactational output. © 1995 Wiley-Liss, Inc.     

Fructose 2,6-bisphosphate, sugar phosphates and adenine nucleotides in the regulation of glucose metabolism in the lactating rat mammary gland

Fructose 2,6-bisphosphate is present in the rat mammary gland, rising from a value of 1.4 nmol/g in pregnancy to 4.3 nmol/g tissue at 14 days lactation; the equivalent values calculated/ml intracellular water are 5.2 and 11.6 nmol, respectively. The tissue content of fructose 6-phosphate, fructose 1,6-bisphosphate, ATP and phosphoenolpyruvate remain relatively constant in the transition from pregnancy to the height of lactation. The changes in AMP, cyclic AMP, and citrate content of the mammary gland during lactation are such as to promote an increase in fructose 2,6-bisphosphate formation and flux through phosphofructokinase.