Giacomo Giacobini

Effects of the type A toxin fromClostridium botulinum on the development of skeletal muscles and of their innervation in chick embryo

Abstract Chronic injections of high doses of the type A toxin fromClostridium botulinum in the yolk sac of chick embryos cause a marked atrophy of skeletal muscles. However, in contrast with what was previously observed after injection ofNaja nigricollis α-toxin, the motor innervation shows little regression. Endplates and motor nerve fibers are numerous and the total content of the muscle in choline acetyltransferase does not change. Ultrastructural studies show that in the muscles of embryos treated bybotulinum toxin many endplates are established between motor nerve fibers and highly immature contractile elements such as myoblasts and myotubes.

Neanderthal child and adult remains from a Mousterian deposit in Northern Italy (Caverna delle fate, finale ligure)

Recent identification of human skeletal material from the early Wurmian bone assemblage found in the Caverna delle Fate, Finale Ligure, N. Italy, at the end of the 19th century has provided the first certain Neanderthalian remains of Northern Italy. A frontal bone fragment (Le Fate I) and a hemimandible (Le Fate II) are from an 8–10-year-old child and add to the as yet scanty knowledge of Neanderthal infant morphology. The third fragment (Le Fate III) (mandible fragment) is from an adult. Evolutionary trends involving several morphological features and in apparent contrast with the absolute age of the specimens (75,000−14,000+21,000 and 82,000−25,00036,000 yr B.P., as calculated by direct non-destructive high-resolution gamma-ray spectrometry of the bones from the 231Pa/235U and from the 230Th/234U ratios respectively) are described. The data as a whole lend further support to the suggestion that a Mediterranean Neanderthal population may have existed.

The Neanderthal in the karst: First dating, morphometric, and paleogenetic data on the fossil skeleton from Altamura (Italy)

In 1993, a fossil hominin skeleton was discovered in the karst caves of Lamalunga, near Altamura, in southern Italy. Despite the fact that this specimen represents one of the most extraordinary hominin specimens ever found in Europe, for the last two decades our knowledge of it has been based purely on the documented on-site observations. Recently, the retrieval from the cave of a fragment of bone (part of the right scapula) allowed the first dating of the individual, the quantitative analysis of a diagnostic morphological feature, and a preliminary paleogenetic characterization of this hominin skeleton from Altamura. Overall, the results concur in indicating that it belongs to the hypodigm of Homo neanderthalensis, with some phenetic peculiarities that appear consistent with a chronology ranging from 172xa0±xa015xa0ka to 130.1xa0±xa01.9xa0ka. Thus, the skeleton from Altamura represents the most ancient Neanderthal from which endogenous DNA has ever been extracted.

Richness and Diversity of Burial Rituals in the Upper Paleolithic

Among the cultural innovations by which the Upper Palaeolithic period is characterized, those relating to burial practices furnish the possibility of evaluating the profound changes which differentiated this era from the Middle Palaeolithic. The graves of the Upper Palaeolithic offer us a sometimes very compelling glimpse of the complexity of the symbolic, cognitive and social environment of those peoples, as well as of the evolution and diversification over time and space of their rituals associated with death. This article considers the set of burials discovered to date within the boundaries of Italy as particularly representative of these features. Numerous, diverse and well-endowed, they provide important information about the peoples of the Upper Palaeolithic and of the way they responded to death. These graves also represent a significant body of evidence for the debate on the degree to which Palaeolithic man can be considered culturally fully human and the extent to which he intentionally buried his dead.

From number sense to number symbols. An archaeological perspective

How and when did hominins move from the numerical cognition that we share with the rest of the animal world to number symbols? Objects with sequential markings have been used to store and retrieve numerical information since the beginning of the European Upper Palaeolithic (42 ka). An increase in the number of markings and complexity of coding is observed towards the end of this period. The application of new analytical techniques to a 44–42 ka old notched baboon fibula from Border Cave, South Africa, shows that notches were added to this bone at different times, suggesting that devices to store numerical information were in use before the Upper Palaeolithic. Analysis of a set of incisions on a 72–60 ka old hyena femur from the Les Pradelles Mousterian site, France, indicates, by comparison with markings produced by modern subjects under similar constraints, that the incisions on the Les Pradelles bone may have been produced to record, in a single session, homologous units of numerical information. This finding supports the view that numerical notations were in use among archaic hominins. Based on these findings, a testable five-stage scenario is proposed to establish how prehistoric cultures have moved from number sense to the use of number symbols. This article is part of a discussion meeting issue ‘The origins of numerical abilities’.

Behavior of the cholinergic system in the rat brachial plexus after contralateral neurotomy

Abstract Changes in the activity of specific proteins of the cholinergic system were measured in the rat spinal cord (C5 through T1 levels), secondary trunks of the brachial plexus, and extensores carpi muscles of one antimere, at various periods after contralateral transection of the brachial plexus. Choline acetyltransferase (ChAc) specific activity significantly decreased to approximately 50% of the control in all three regions tested within 7 to 16 days; by the 35th day, it had returned to the control values. The behavior of acetylcholinesterase (AChE) specific activity was similar to that for ChAc in nerves and muscles, whereas in the spinal cord it did not display any significant variation. The total (per muscle) activity of the cholinergic receptor (ACh-R) increased to more than 200% of the control muscles, even though its specific activity did not change during the experiment. We suggest that some alteration in the transfer of information between normal and contralateral (axotomized) motoneurons occurs after transection of a peripheral nerve. Several factors could be involved, particularly the interruption of crossed reflex arcs. The neurochemical changes observed may be triggered by a marked decrease in ChAc synthesis in the motoneuron cell body. Whatever the mechanism involved, it appears that some events occurring in the damaged neurons also occur, either wholly or in part, in the contralateral, unimpaired neurons. It also appears that the changes in cholinergic protein activities that develop in muscles after contralateral neurotomy partially mimic those observed after muscular denervation.

The skull and vertebral column pathology of Ancient Egyptians. A study of the Marro Collection

Abstract The skull and vertebral column pathology of the Ancient Egyptian skeletal remains of the Marro Collection (1118 individuals) is mainly represented by “common” degenerative and inflammatory osteo-articular alterations. Apart from these, three cases of ankylosing spondylitis and two cases of probable multiple myeloma are described in detail. The frequency of these conditions seems to be almost the same as in modern times. Furthermore, a skull with larger osteolitic areas of probable metastatic origin is described.

Skeletal development of an orang-utan premature Newborn: A comparative study with man

The state of skeletal ossification of a premature newborn of Pongo pygmaeus has been studied radiologically. it is described comparatively to a human foetus of the same age (210–230 days of intrauterine life). Correlations may be established between the degree of development of some skeletal districts (mainly skull and foot) and the different speicalizations of the two evolutionary lines.

A Simple Method for Studying the Surface of Fired Bullets: Varnishes for Replicas

The authors describe a new, simple, and rapid method for studying the surface of fired bullets. They cmploy a transparent varnish (Vernis Replic) that can be observed under a light microscope or mounted on normal slide frames and directly projected.

A Developmental Model for Studying Choline Acetyltransferase Transport in Chick Motoneurons

The proximodistal axonal transport of choline acetyltransferase (ChAc) has been studied in the chick sciatic nerve in the absence of any experimental manipulation. The phenomenon utilized by us is a physiological transient fall in the activity of ChAc. This fall occurs in most areas of the chick central nervous system after hatching, and moves toward the periphery along the nerves. Having ruled out the presence of transient inhibitors, the movement of the fall towards skeletal muscles has been considered to correspond to the proximodistal transport of ChAc. The calculated average velocity is 7.86 mm/day, corresponding to the slow rate of transport. Nevertheless, the kinematics study suggests that the velocity varies along the nerve from a state of rest to an intermediate rate of transport (16 mm/day). The possible influence of variations in the resistance of the conductor on these changes in velocity is discussed.