Comparative anatomical analysis of human trisomies 13, 18, and 21: I. The forelimb

Human trisomies 13, 18, and 21 exhibit specific neuromuscular phenotypes (Pettersen and Bersu, '82) which include a high proportion of neuromuscular forelimb variations, many of which are atavistic in nature (de Beer, '58; Barash et al., '79; Aziz, '81a). In order to test the neuromuscular phenotype, examine the atavistic nature, and analyze the developmental delay of the trisomy forearm musculature, we dissected the forelimbs of five trisomy 13, ten trisomy 18, and two trisomy 21 cases. Our dissections compare favorably with the existing published trisomy cases (Opitz et al., '79; Pettersen and Bersu, '82). Additionally, we found significant differences in the stage at which developmental arrest occurred in trisomies 13 and 18 for the pectoral complex, extensor digitorum profundus, and intrinsic hand musculature. Some of these muscles, which occur normally in nonhuman primates (Cihak, '67, '69; Dunlap et al., '85), also appear briefly in normal human ontogeny (Cihak, '72), constituting further evidence for developmental delay in aneuploids. The disproportionately effected limb tissues also lend support to the evidence for some degree of autonomy in their development in normal individuals. Our observations are consistent with Shapiro's amplified developmental instability model ('83). Aneuploids may be viewed as genetic variants from which much may be learned about normal limb development, how aneuploidy affects dysmorphogenesis, and the kind of information which exists on the duplicated (or monosomic) chromosome.     

Estimation of the effective static moment arms of the tendons in the index finger extensor mechanism

A novel technique to estimate the contribution of finger extensor tendons to joint moment generation was proposed. Effective static moment arms (ESMAs), which represent the net effects of the tendon force on joint moments in static finger postures, were estimated for the 4 degrees of freedom (DOFs) in the index finger. Specifically, the ESMAs for the five tendons contributing to the finger extensor apparatus were estimated by directly correlating the applied tendon force to the measured resultant joint moments in cadaveric hand specimens. Repeated measures analysis of variance revealed that the finger posture, specifically interphalangeal joint angles, had significant effects on the measured ESMA values in 7 out of 20 conditions (four DOFs for each of the five muscles). Extensor digitorum communis and extensor indicis proprius tendons were found to have greater MCP ESMA values when IP joints are flexed, whereas abduction ESMAs of all muscles except extensor digitorum profundus were mainly affected by MCP flexion. The ESMAs were generally smaller than the moment arms estimated in previous studies that employed kinematic measurement techniques. Tendon force distribution within the extensor hood and dissipation into adjacent structures are believed to contribute to the joint moment reductions, which result in smaller ESMA values.     

Taxonomy and phylogeny of the tribePlucheeae (Asteraceae)

The tribePlucheeae (Benth.)A. Anderb., has been analysed cladistically by means of a computerized parsimony program (Hennig 86), using theArctotideae as outgroup. The results of the analysis are presented in a consensus tree and one cladogram. Four major monophyletic subgroups can be recognized: TheColeocoma group (3 genera), thePterocaulon group (3 genera), theLaggera group (6 genera), and thePluchea group (12 genera). All recognized genera are described and most genera are supplied with taxonomical notes including comments on their taxonomic status. Genera such asBlumea, Pluchea, andEpaltes are demonstrated to be unnatural assemblages.Monarrhenus andTessaria are both closely related to thePluchea complex. The old generic nameLitogyne Harv. has been taken up for one species ofEpaltes, the genusRhodogeron is reduced to a synonym ofSachsia, and the following new combinations are made;Litogyne gariepina (DC.)A. Anderb., andSachsia coronopifolia (Griseb.)A. Anderb.     

Evolution of aromatic biosynthesis and fine-tuned phylogenetic positioning of Azomonas,Azotobacter and rRNA group I pseudomonads

The evolutionary history of biochemical pathways can be determined in microbial groupings for which phylogenetic trees have been established. This has been demonstrated best in Superfamily B, an assemblage of rRNA homology groups containing lineages that lead to genera such as Escherichia and other enteric microbes, Pseudomonas (Group I), Xanthomonas, Oceanospirillum, and Acinetobacter. The rRNA homology group that defines Group I pseudomonads also includes Azomonas and Azotobacter, but particular dendrogram points of evolutionary divergence for these genera within Superfamily B have not been established. Phylogenetic relationships at such intergeneric levels can be deduced by analysis of aromaticpathway enzyme arrangement and regulation in selected groupings where dynamic evolutionary changes have occurred. A case in point is illustrated by Axomonas insignis, Azotobacter paspali, and Azotobacter vinelandii — a grouping that appears to be homogeneous with respect to the evolutionary state of the aromatic pathway. The conclusion that this phylogenetic cluster diverges from an ancestor common to pseudomonad subgroup Ia (rather than to subgroup Ib) is based upon the absence of chorismate mutase-F and arogenate dehydratase, enzymes making up a twostep pathway of phenylalanine biosynthesis that is absent in subgroup Ia, but present in subgroup Ib. Of further interest, Azomonas insignis and Azotobacter sp. were found to comprise a distinctive and recently evolved sublineage, differing from subgroup Ia species in their loss of a regulatory isozyme of 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (ADHP synthase-trp) that is subject to feedback inhibition by l-tryptophan. DAHP synthase-trp is an ancient character state of Superfamily B that has been retained during the evolutionary history of most members of this Superfamily.Abbreviation DAHP 3-Deoxy-d-arabino-heptulosonate 7-phosphate     

Fluorescence demonstration of a cathepsin H-like protease in cardiac, skeletal and vascular smooth muscles

Summary A cathepsin H-like enzyme was localized by histochemical techniques in cardiac muscle, extensor digitorum longus and soleus skeletal muscles, and vascular smooth muscle. Using the specific exopeptidase activity of this enzyme against the substrate arg-4-methoxy--naphthylamide, valid histochemical assay conditions were developed. More fluorescent granules were observed in cardiac muscle than in the soleus and about equal amounts in vascular smooth muscle and the extensor digitorum longus. The reaction rate was enhanced by chloride ions and inhibited by 1mm p-chloromercuribenzoate. The maximal activity was observed between pH 5.5 and 6.0. Chemical fixation with periodate-lysine-paraformaldehyde preserved a small amount of enzymatic activity.     

The fitness costs and benefits of trisomy of each Candida albicans chromosome

Candida albicans is a prevalent human fungal pathogen. Rapid genomic change, due to aneuploidy, is a common mechanism that facilitates survival from multiple types of stresses including the few classes of available antifungal drugs. The stress survival of aneuploids occurs despite the fitness costs attributed to most aneuploids growing under idealized lab conditions. Systematic study of the aneuploid state in C. albicans has been hindered by the lack of a comprehensive collection of aneuploid strains. Here, we describe a collection of diploid C. albicans aneuploid strains, each carrying one extra copy of each chromosome, all from the same genetic background. We tested the fitness of this collection under several physiological conditions including shifts in pH, low glucose, oxidative stress, temperature, high osmolarity, membrane stress, and cell wall stress. We found that most aneuploids, under most conditions, were less fit than their euploid parent, yet there were specific conditions under which specific aneuploid isolates provided a fitness benefit relative to the euploid parent strain. Importantly, this fitness benefit was attributable to the change in the copy number of specific chromosomes. Thus, C. albicans can tolerate aneuploidy of each chromosome and some aneuploids confer improved growth under conditions that the yeast encounters in its host niches.     

BIOSYSTEMATIC STUDIES IN THE BOUTELOUA CURTIPENDULA COMPLEX. I. THE ANEUPLOID RHIZOMATOUS B. CURTIPENDULA OF TEXAS

Gould , F. W., and Z. J. Kapadia . (A. & M. College of Texas, College Station.) Biosystematic studies in the Bouteloua curtipendula complex. I. The aneuploid rhizomatous B. curtipendula of Texas. Amer. Jour. Bot. 49(8): 887–891. Illus. 1962.—Widespread throughout central U.S. is a rhizomatous form of B. curtipendula that basically is tetraploid (2n = 40). In the southwest the predominant type is a caespitose aneuploid with a high chromosome number (2n = ca. 80 to 2n = ca. 102). The present study has shown the presence of an extensive series of rhizomatous aneuploids in central Texas, with chromosome numbers ranging from 2n = 41 to 2n = 64. The distribution of these plants is centered about the region of overlap in the ranges of the 2 previously mentioned types. Available evidence indicates that the rhizomatous aneuploids have arisen through hybridization of the caespitose aneuploids and the rhizomatous tetraploids.     

Musculature of the ovipositor of Lenitovena trigona (Matsumura) (Diptera, Tephritidae) with reference to the larval saprophagy

The larvae of most Tephritidae are endobiotic in various living plants and are therefore convenient objects for analysis of the associations of this dipteran family with seed plants. The structure of the sclerites and musculature of the ovipositor of Lenitovena trigona (Matsumura) a Far Eastern tephritid of the tribe Acanthonevrini with initially saprobiont larva, was investigated to facilitate understanding of the morphological changes in the adults associated with larval shift from saprophagous to herbivorous habit. Differences between the ovipositor of L. trigona and those of species of the genera Urophora, Ceratitis, and Rhagoletis with endophytic larvae have been found; the ovipositor musculature of these genera has been described by Dean (1935), Nanna (1938), and Berube and Zacharuk (1983).     

Genetic basis for dosage sensitivity in Arabidopsis thaliana

Aneuploidy, the relative excess or deficiency of specific chromosome types, results in gene dosage imbalance. Plants can produce viable and fertile aneuploid individuals, while most animal aneuploids are inviable or developmentally abnormal. The swarms of aneuploid progeny produced by Arabidopsis triploids constitute an excellent model to investigate the mechanisms governing dosage sensitivity and aneuploid syndromes. Indeed, genotype alters the frequency of aneuploid types within these swarms. Recombinant inbred lines that were derived from a triploid hybrid segregated into diploid and tetraploid individuals. In these recombinant inbred lines, a single locus, which we call SENSITIVE TO DOSAGE IMBALANCE (SDI), exhibited segregation distortion in the tetraploid subpopulation only. Recent progress in quantitative genotyping now allows molecular karyotyping and genetic analysis of aneuploid populations. In this study, we investigated the causes of the ploidy-specific distortion at SDI. Allele frequency was distorted in the aneuploid swarms produced by the triploid hybrid. We developed a simple quantitative measure for aneuploidy lethality and using this measure demonstrated that distortion was greatest in the aneuploids facing the strongest viability selection. When triploids were crossed to euploids, the progeny, which lack severe aneuploids, exhibited no distortion at SDI. Genetic characterization of SDI in the aneuploid swarm identified a mechanism governing aneuploid survival, perhaps by buffering the effects of dosage imbalance. As such, SDI could increase the likelihood of retaining genomic rearrangements such as segmental duplications. Additionally, in species where triploids are fertile, aneuploid survival would facilitate gene flow between diploid and tetraploid populations via a triploid bridge and prevent polyploid speciation. Our results demonstrate that positional cloning of loci affecting traits in populations containing ploidy and chromosome number variants is now feasible using quantitative genotyping approaches.     

Upright posture of the human and the morphologic evolution of the musculi extensores digitorum pedis with reference to evolutionary myology

A brief literature review is made of the morphological changes in the bones of the lower limbs of man, which are the result of his upright walk. The author's task has been to study the morphological changes of Mm. extensores digitorum pedis from the viewpoint of evolutionary myology. The following material has been studied: Lower limbs of adults, 151 less than or equal to N less than or equal to 358. Pelvic limbs of Marsupialia, Insectivora, and non-hominide primates; N = 122. Lower limbs of human embryos and fetuses; N = 71. The following acknowledgements are the author's own studies. They begin with an evolutionary-myological study of m. extensor hallucis longus and of m. extensor digitorum longus, together with m. peroneus tertius.     

Hand use and metacarpal robusticity in Catarrhini

Recent studies,Rightmire (1972) andDay andScheuer (1973), have investigated the affinities of early hominid metacarpals from Swartkrans. Because of its extensive use in the analysis of metatarsals, the index of robusticity has also been applied to some fossil metacarpals. From the metatarsal analyses, it has been shown that within a group a variety of robusticity patterns exist with the average pattern occuring approximately 50 per cent of the time. This, coupled with the fact that it has also been shown that within the order Primates the pattern is not necessarily diagnostic of any locomotor category, has led us to investigate the usefulness of such an index in assessing primate metacarpals. In this study, metacarpal robusticity patterns and the Total Robusticity Quotient are established for seven cercopithecoid genera and the results correlated with hand use. It is found that although patterns of robusticity are not diagnostic of locomotor categories, the TRQ relates well to hand use: low TRQ's are found in primates which use their hands to walk on a flat substrate, while high TRQ's are diagnostic of arm swinging animals. Primates with reduced thumb use in a precision grip and little manipulative use of the hand have higher TRQ's than those with a good precision grip. The model derived from our sample of Cercopithecoidea is tested with a hominoid sample of four genera and found to be similarly applicable.     

In vivo angiogenesis in adult rat skeletal muscle: early changes in capillary network architecture and ultrastructure

The individual structural stages in capillary growth have been identified during development and under pathological circumstances in adults (wound healing, tumors), but there are no data to indicate whether these steps are similar when angiogenesis is induced in a fully differentiated microvascular bed in normal, uninjured adult skeletal muscle. In this study changes in capillary ultrastructure were correlated with capillary density and network morphology to elucidate the sequelae of angiogenesis in adult rat extensor digitorum longus (EDL) muscle whose activity was increased by stimulation at 10rHz (8rh/day). This resulted in an increased capillary/fiber (C/F) ratio (based on staining for alkaline phosphatase) after 4rdays; by 7rdays C/F ratio was increased further, by approximately 50%. The ultrastructure of capillary endothelium in both the EDL and extensor hallucis proprius (EHP) was similar to control muscles after 2rdays of stimulation, whereas endothelial cells in some capillaries in muscle stimulated for 4rdays revealed signs of metabolic activation such as proliferation of organelles (Golgi apparatus, endoplasmic reticulum, ribosomes and mitochondria) and fewer pinocytic vesicles. Luminal surfaces were often irregular with numerous pseudopodial processes. Basement membranes were always present but amorphous regions were observed, particularly near pericyte processes. Unusually small capillary profiles, with either a slit-like lumen or with cisternae but no lumen, probably represented capillary sprouts. The interstitium contained increased collagenous and granular extracellular matrix surrounding capillaries, and numerous activated fibroblasts which were closely apposed to many capillaries. Capillary growth in EHP was also evaluated by confocal microscopy using whole mounts. The complex pattern of vessels underwent remodelling between 2 and 7rdays of stimulation, resulting in more tortuous capillaries with numerous sprouts and loops. These combined observations suggest that angiogenesis may occur by a combination of sprouting, intussusceptive growth and elongation; also, that activation of endothelial cells occurs at the same time as disturbance of basement membranes during the earliest phase of growth and remodelling of the capillary bed. These changes are postulated to occur in connection with increased shear stress and/or capillary wall tension, which have been demonstrated previously.     

Finger-specific flexor recruitment in humans: depiction by exercise-enhanced MRI.

To evaluate the spatial distribution of human forearm musculature stressed by finger-specific exercise, magnetic resonance imaging was performed in conjunction with exercise protocols designed to separately stress the flexor digitorum superficialis and flexor digitorum profundus. These muscles were shown to consist of subvolumes selectively recruited by flexion of the individual fingers. Knowledge of the finger-specific regions of muscle recruitment during finger flexion could improve sampling accuracy in electromyography, biopsy, magnetic resonance spectroscopy, and invasive vascular sampling studies of hand exercise.     

Systematic revision of the endemic deerHaploidoceros n. gen.mediterraneus (Bonifay, 1967) (Mammalia, Cervidae) from the Middle Pleistocene of Southern France

New osteological material of the endemic deer from Lunel-Viel and l’Igue des Rameaux (France) reveals its evolutionary specialization, and gives reason for establishing a new genus,Haploidoceros, with a single speciesH. mediterraneus (Bonifay, 1967). The cranial proportions and morphology suggest thatH. mediterraneus is close to the Late Villafranchian speciesMetacervocerus rhenanus, which may be a possible forerunner of the deer under study. The evolutionary origin ofH. mediterraneus took place in the Iberian glacial refugia during the “Mindel glaciation” of the early Middle Pleistocene. The North-East distribution ofH. mediterraneus was limited by unfavorable climate influence of the Arctic and Alpine Ice Shields.      

Evolution and homologies of primate and modern human hand and forearm muscles, with notes on thumb movements and tool use

In this paper, we explore how the results of a primate-wide higher-level phylogenetic analysis of muscle characters can improve our understanding of the evolution and homologies of the forearm and hand muscles of modern humans. Contrary to what is often suggested in the literature, none of the forearm and hand muscle structures usually present in modern humans are autapomorphic. All are found in one or more extant non-human primate taxa. What is unique is the particular combination of muscles. However, more muscles go to the thumb in modern humans than in almost all other primates, reinforcing the hypothesis that focal thumb movements probably played an important role in human evolution. What makes the modern human thumb myology special within the primate clade is not so much its intrinsic musculature but two extrinsic muscles, extensor pollicis brevis and flexor pollicis longus, that are otherwise only found in hylobatids. It is likely that these two forearm muscles play different functional roles in hylobatids and modern humans. In the former, the thumb is separated from elongated digits by a deep cleft and there is no pulp-to-pulp opposition, whereas modern humans exhibit powerful thumb flexion and greater manipulative abilities, such as those involved in the manufacture and use of tools. The functional and evolutionary significance of a third peculiar structure, the intrinsic hand structure that is often called the ‘interosseous volaris primus of Henle’ (and which we suggest is referred to as the musculus adductor pollicis accessorius) is still obscure. The presence of distinct contrahentes digitorum and intermetacarpales in adult chimpanzees is likely the result of prolonged or delayed development of the hand musculature of these apes. In relation to these structures, extant chimpanzees are more neotenic than modern humans.     

Beziehungen zwischen Körperbau und Lebensweise bei Blenniidae (Pisces) des Roten Meeres

The muscle and skeleton anatomy of the pectoral, pelvic, and anal fins are described in 3 Salariin Blenniidae: Salarias fasciatus (sublittoral), Istiblennius edentulus (eulittoral), Alticus kirkii (supralittoral). In A. kirkii these organs are adapted to a climbing habit on the steep rocks beyond the water. The results are compared with those found in Periophthalmus.

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Abbildungserklärungen B Basale - Cl Cleithrum - Co Coracoid - Creld Crista cleithri dorsalis - Crele Crista cleithri externa - H Haken an den Lepidotrichen der Ventralia - Lep Lepidotrichen - Pel Postcleithrum - Prsv Processus spinae ventralis - Pt Posttemporale - Rad Radiale - Scl Supracleithrum - SCl Symphyse des Cleithrum - Scp Scapula - abpr M. abductor profundus - adpr M. adductor profundus - arre M. arrector externus - arri M. arrector internus - cord M. coraco-radialis - dep M. depressor (Analis) - dprrd M. depressor radiorum (Pectoralia) - er M. erector - extpr M. extensor proprius - fls M. flexor superficialis - inc M. inclinator - levs M. levator superficialis - mes M. mesoventralis - rtrd M. retractor dorsalis - rtris M. retractor ischii - rtrv M. retractor ventralis Mit Unterstützung der Deutschen Forschungsgemeinschaft.     

d-Lysine production from l-lysine by successive chemical racemization and microbial asymmetric degradation

In order to develop a practical process for d-lysine production from l-lysine, successive chemical racemization and microbial asymmetric degradation were investigated. The racemization of l-lysine proceeded quantitatively at elevated temperatures. A sample␣of 1000 strains of bacteria, fungi, yeast and actinomyces were screened for the ability to degrade l-lysine asymmetrically. Microorganisms belonging to the Achromobacter, Agrobacterium, Candida, Comamonas, Flavobacterium, Proteus, Providencia, Pseudomonas and Yarrowia genera exhibited a high l-lysine-degrading activity. Comamonas testosteroni IAM 1048 was determined to be the best strain and used as a biocatalyst for eliminating the l isomer. The degradation rate of l-lysine with C. testosteroni IAM 1048 was influenced by pH, temperature and agitation speed. Under the optimal conditions, the l isomer in a 100-g/l mixture of racemic lysine was completely degraded within 72 h, with 47 g d-lysine/l left in the reaction mixture. Crystalline d-lysine, with a chemical purity greater than 99% and optical purity of 99.9% enantiomeric excess, was obtained at a yield of 38% from the reaction mixture by simple purification. An engineering analysis of l-lysine racemization and microbial degradation was carried out to establish the basis of process design for d-lysine production. Received: 24 September 1996 / Received last revision: 8 November 1996 / Accepted: 23 November 1996     

Fluctuation of a clone 46,XX,i(7q) in bone marrow in a Fanconi anaemia

Summary Fixed metaphase chromosomes of different species and genera of Primates (five species of Macaca genus and Callithrix acchus) have been studied after Alu I restriction enzyme digestion and DA-DAPI counterstaining, in the attempt to determine some qualitative characteristics of their DNAs and specifically of the DNA localized in the heterochromatic components of the karyotypes. The results have been discussed in the light of those already published on humans, confirming the potentiality of this approach in the study of the phyloevolutive relationships in Primates.     

The influence of passive stretch on the growth and protein turnover of the denervated extensor digitorum longus muscle

At 7 days after cutting the sciatic nerve, the extensor digitorum longus muscle was smaller and contained less protein than its innervated control. Correlating with these changes was the finding of elevated rates of protein degradation (measured in vitro) in the denervated tissue. However, at this time, rates of protein synthesis (measured in vitro) and nucleic acid concentrations were also higher in the denervated tissue, changes more usually associated with an active muscle rather than a disused one. These anabolic trends have, at least in part, been explained by the possible greater exposure of the denervated extensor digitorum longus to passive stretch. When immobilized under a maintained influence of stretch the denervated muscle grew to a greater extent. Although this stretch-induced growth appeared to occur predominantly through a stimulation of protein synthesis, it was opposed by smaller increases in degradative rates. Nucleic acids increased at a similar rate to the increase in muscle mass when a continuous influence of stretch was imposed on the denervated tissue. In contrast, immobilization of the denervated extensor digitorum longus in a shortened unstretched state reversed most of the stretch-induced changes; that is, the muscle became even smaller, with protein synthesis decreasing to a greater extent than breakdown after the removal of passive stretch. The present investigation suggests that stretch will promote protein synthesis and hence growth of the extensor digitorum longus even in the absence of an intact nerve supply. However, some factor(s), in addition to passive stretch, must contribute to the anabolic trends in this denervated muscle.     

<Emphasis Type="Italic">Enigmagraptus</Emphasis> n. gen., a new graptoloid (Přídolí, Silurian,New South Wales,Australia)

Enigmagraptus n. gen. comprises a group of the smallest known graptolites, with problematical evolutionary ancestors. The species described, all of Přídolí age are:E. yassensis (Rickards &Wright, 1999),E. cf.yassensis, E. mitchelli (Rickards &Wright, 1999) andE. pennyae n. sp.