Showing papers by "University of Bordeaux published in 1994"
TL;DR: In this paper, the authors show that depending on the amount of lithium ( x ) intercalated in V 2 O 5, several structural modifications are observed, such as a gliding of one layer out of two leading to the δ-type structure.
506 citations
TL;DR: In this article, the authors measured the 14C difference between the atmosphere and the North Atlantic surface during a prominent climatic period of the last deglaciation, the Younger Dryas event (YD).
362 citations
TL;DR: There are age-related changes in long-bone diaphyseal envelope sensitivity to increased mechanical loading, with the periosteal envelope more responsive prior to mid-adolescence, and the endosteal envelopes more responsive thereafter.
Abstract: The influence of developmental factors on long-bone crosssectional geometry and articular size in modern humans is investigated using two approaches: (1) an analysis of the effects of increased mechanical loading on long-bone structure when applied during different developmental periods, using data collected for a study of upper limb bone bilateral asymmetry in professional tennis players; and (2) an analysis of the relative timing of age changes in femoral dimensions among juveniles from the Pecos Pueblo Amerindian archaeological sample. Results of these analyses are used to interpret the femoral morphology of three pre-Recent Homo juveniles—the H. erectus KNM-WT 15000 and the archaic H. sapiens La Ferrassie 6 and Teshik-Tash 1—as well as observed differences in postcranial morphology between adult Recent and earlier Homo (Ruff et al., 1993).
Our findings indicate the following: (1) There are age-related changes in long-bone diaphyseal envelope sensitivity to increased mechanical loading, with the periosteal envelope more responsive prior to mid-adolescence, and the endosteal envelope more responsive thereafter. The periosteal expansion and endosteal contraction of the diaphysis documented earlier for adult pre-Recent Homo relative to Recent humans (Ruff et al., 1993) is thus consistent with a developmental response to increased mechanical loading applied throughout life. The relatively large medullary cavity in the 11–12-year-old KNM-WT 15000 femur is also consistent with this model. However, the two archaic H. sapiens juveniles show relatively small medullary cavities, possibly indicating a modified developmental pattern in this group. (2) Articulations follow a growth pattern similar to that of long-bone length (and stature), while cross-sectional diaphyseal dimensions (cortical area, second moments of area) show a contrasting growth pattern, with slower initial growth from childhood through mid-adolescence, followed by a “catch-up” period that continues through early adulthood. This latter pattern is more similar to the growth curve for body weight, and may in fact partially reflect adaptation of the diaphysis to increased weight bearing. Because of these different growth patterns, articulations appear relatively large, and diaphyseal breadths relatively small during late childhood to mid-adolescence (i.e., about 9–13 years), when compared to adults from the same population. KNM-WT 15000 shows this same proportional difference from adult early Homo specimens, which is therefore interpreted as simply a developmental consequence of his age at death. (3) When standardized for differences in body size and shape, midshaft femoral cross-sectional areas for the three pre-Recent juveniles in our sample, which span an age range from about 4 to 12 years, all fall in the upper part of the general data scatter for modern juveniles of a similar age. This is very similar to the pattern we found earlier for adult Homo specimens (Ruff et al., 1993). Thus, increased diaphyseal robusticity relative to modern humans, and the mechanicalhehavioral factors that produced this structural difference, were apparently as characteristic of immature as of adult pre-Recent Homo. © 1994 Wiley-Liss, Inc.
336 citations
TL;DR: In this article, the averaged form of the Stokes equations in terms of weighting functions was developed, and it was shown at what point one must choose a media-specific weighting function in order to achieve spatially smoothed transport equations.
Abstract: In this paper we develop the averaged form of the Stokes equations in terms of weighting functions. The analysis clearly indicates at what point one must choose a media-specific weighting function in order to achieve spatially smoothed transport equations. The form of the weighting function that produces the cellular average is derived, and some important geometrical theorems are presented.
271 citations
TL;DR: By this method it was possible to detect, in the same sample and at the same time, intact cells, cells undergoing apoptosis, and dead cells resulting from apoptotic and/or necrotic processes.
Abstract: A flow cytometric method to detect apoptotic cells is described. This method is based on the detection of differences in chromatin condensation with Hoechst 33342 as a probe and the detection of dead cells with propidium iodide as a probe for membrane damage. By this method it was possible to detect, in the same sample and at the same time, intact cells, cells undergoing apoptosis, and dead cells resulting from apoptotic and/or necrotic processes. The method was successfully applied to the detection of apoptotic cells in two human cell models: cultured polymorphonuclear cells and the U937 cell line treated with antitumoral drugs. Staining specificity for apoptotic cells was controlled by cell sorting of the presumed apoptotic population, followed by morphologic examination or DNA analysis of the sorted populations. The usefulness of such a method is discussed in terms of applications in the analysis of heterogeneous clinical samples, populations with low DNA degradation during apoptosis, and cell cycle position of the apoptotic cells.
259 citations
TL;DR: Incidence rates of dementia, Alzheimer's disease and vascular dementia in a community population of South-Western France did not level off with age and were not different between genders.
Abstract: Background Dementia is a growing problem in developed countries. The aim of this paper is to estimate incidence rates of dementia, Alzheimer's disease and vascular dementia in a community population of South-Western France. Methods A sample of 2792 subjects was selected and followed-up 1 year and 3 after the initial screening. At each visit, a standardized questionnaire was administered by trained psychologists. Demented subjects were identified using a two-step procedure. The first step consisted of a systematic screening by the psychologist using DSM IIIR criteria for dementia. In the second step, subjects who fulfilled the DSM IIIR criteria were examined by a neurologist. NINCDS-ADRDA criteria were applied to diagnose Alzheimer's disease. Results Incidences of dementia and Alzheimer's disease were estimated at 16.3 and 11.4 per 1000 per year, respectively. Incidence estimates increased with age from 2 per 1000 in subjects aged 65-69 years to 74 per 1000 in subjects > 90 years. Incidence estimates of Alzheimer's disease showed the same increased from 0.7 per 1000 to 66 per 1000. Incidences of dementia and of Alzheimer's disease did not level off with age and were not different between genders.
246 citations
TL;DR: This structure ofacterioferritin of Escherichia coli, also known as cytochrome b1, is a hollow, nearly spherical shell made up of 24 identical protein subunits and 12 haems and it is found that each haem is bound in a pocket formed by the interface between a pair of symmetry-related subunits.
Abstract: Bacterioferritin of Escherichia coli, also known as cytochrome b1, is a hollow, nearly spherical shell made up of 24 identical protein subunits and 12 haems. We have solved this structure in a tetragonal crystal form at 2.9 A resolution. We find that each haem is bound in a pocket formed by the interface between a pair of symmetry-related subunits. The quasi-twofold axis of the haem is closely aligned with the local twofold axis relating these subunits. The axial ligands of the haem are sulphurs of two equivalent methionyl residues (Met 52) from the symmetry-related subunits. A cluster of four water molecules is trapped in the gap between the upper edge of the haem and two extended protein loops which close off the haem from the outer aqueous environment. This is the first structure of a bis-methionine ligated haem-binding site and the first case of a twofold symmetric haem-binding site.
204 citations
TL;DR: This work considers transport in ordered and disordered porous media using singlephase flow in rigid porous media as an example and defines order and disorder in terms of geometrical integrals that arise naturally in the method of volume averaging.
Abstract: In this work we consider transport in ordered and disordered porous media using singlephase flow in rigid porous mediaas an example. We defineorder anddisorder in terms of geometrical integrals that arise naturally in the method of volume averaging, and we show that dependent variables for ordered media must generally be defined in terms of thecellular average. The cellular average can be constructed by means of a weighting function, thus transport processes in both ordered and disordered media can be treated with a single theory based on weighted averages. Part I provides some basic ideas associated with ordered and disordered media, weighted averages, and the theory of distributions. In Part II a generalized averaging procedure is presented and in Part III the closure problem is developed and the theory is compared with experiment. Parts IV and V provide some geometrical results for computer generated porous media.
192 citations
TL;DR: In this article, the authors used faunal and stable isotope analyses of foraminifera in two sediment cores from the North Atlantic ocean and Norwegian Sea to reconstruct high-resolution records of SST and sea surface salinity during the Eemian interglacial.
Abstract: CHANGING conditions in the North Atlantic region may drive global climate changes1,2. According to previous reconstructions of the last interglacial (the Eemian), North Atlantic sea surface tempera-tures (SSTs) were similar to present-day values3. In the Norwegian Sea, even warmer conditions appeared as a single pulse of short duration4,5, whereas the Greenland ice record suggests that the warm interglacial air temperatures were interrupted by several cold periods6. Here we use faunal and stable-isotope analyses of foraminifera in two sediment cores from the North Atlantic ocean and Norwegian Sea to reconstruct high-resolution records of SST and sea surface salinity (SSS) during the Eemian interglacial. Our results, which differ significantly from the Greenland record6, show a sharp decrease in SST and SSS of the Norwegian Sea, associated with a more moderate cooling and freshening of the North Atlantic at the middle of isotope substage 5e, several millennia before the beginning of continental ice-sheet growth. Changes in the Norweg-ian Sea surface conditions appear to have represented an important climate change affecting global atmospheric and thermohaline circulations.
189 citations
TL;DR: In this paper, a high-sensitivity spectrofluorometer without preconcentration of the samples was used to record the corrected fluorescence spectra of open marine water and the results showed that with an adequate excitation wavelength (313 nm) fluorescence signature can be used to differentiate water masses.
189 citations
TL;DR: It is proved that the same properties of graphs of degree at most k, where k is a fixed integer, can be expressed by monadic second-order formulas using edge and vertex quantifications as well as by monAD second- order formulas using vertex quantification only.
TL;DR: The present results suggest that increased RBC vitamin A may offer some degree of protection against oxidative stress in erythrocytes, but not in plasma where LPO is demonstrated.
TL;DR: Two meta-analyses showed that methotrexate is among the most efficacious of slow-acting antirheumatic agents, together with parenteral gold (sodium aurothiomalate), penicillamine and sulfasalazine, and has one of the best efficacy/toxicity ratios.
Abstract: Methotrexate has been approved for the treatment of refractory rheumatoid arthritis by several regulatory agencies, including the Food and Drug Administration. The tendency is now to prescribe it at earlier stages of the disease. Methotrexate is a well known antifolate. Its exact mechanism of action in rheumatoid arthritis remains uncertain. The polyglutamated derivatives of methotrexate are potent inhibitors of various enzymes, including dihydrofolate reductase and 5-aminoimidazole-4-carboxamide ribonucleotide transformylase. Inhibitory effects on cytokines, particularly interleukin-1, and on arachidonic acid metabolism, as well as effects on proteolytic enzymes, have been reported. Some of them may be linked to the antifolate properties of methotrexate. Overall, the drug appears to act in rheumatoid arthritis as an anti-inflammatory agent with subtle immunomodulating properties. Direct inhibitory effects on rapidly proliferating cells in the synovium have also been suggested. Methotrexate is usually given orally. Marked interindividual variation in its bioavailability has been found. Food intake has no significant effect on the pharmacokinetics of oral methotrexate. Methotrexate undergoes significant metabolism. The functionally important metabolites are the polyglutamated derivatives of methotrexate, which are selectively retained in the cells. Less than 10% of a dose of methotrexate is oxidised to 7-hydroxy-methotrexate, irrespective of the route of administration. This metabolite is extensively (91 to 93%) bound to plasma proteins, in contrast to the parent drug (35 to 50% bound). Methotrexate is mainly excreted by the kidneys. It undergoes tubular secretion and may thereby compete with various organic acid compounds. Early placebo-controlled trials demonstrated that weekly low dosage methotrexate produced early symptomatic improvement in most rheumatoid arthritis patients. Two meta-analyses showed that methotrexate is among the most efficacious of slow-acting antirheumatic agents, together with parenteral gold (sodium aurothiomalate), penicillamine and sulfasalazine. Furthermore, in the short term context of clinical trials, methotrexate has one of the best efficacy/toxicity ratios. There is little evidence that methotrexate, or any available slow-acting antirheumatic agent, is a true disease-modifying drug. However, the probability that a patient will continue methotrexate therapy over time appears quite favourable compared with any other slow-acting antirheumatic drug. Combination therapy with slow-acting drugs has been advised for the management of rheumatoid arthritis, but the evidence currently available does not support general use of combination therapy including methotrexate. Almost all investigations indicated that toxic effects, rather than lack of response, were the major reason for discontinuing methotrexate therapy. An analysis of more than 3000 courses of therapy with 6 slow-acting drugs indicated that the overall toxicity of methotrexate was similar to that of penicillamine and azathioprine. Hydroxychloroquine was the least toxic, followed by sodium aurothiomalate, whereas auranofin was the most toxic. Few predisposing factors to methotrexate toxicity have been clearly identified, and individual susceptibility plays a primary role in determining toxicity. Folate supplementation may decrease the incidence of common adverse effects, but whether it prevents more serious adverse reactions remains to be answered. Gastrointestinal symptoms, stomatitis, increased levels of liver enzymes and mild cytopenia are frequent adverse effects associated with methotrexate therapy. Furthermore, severe, and possibly life-threatening, complications have been reported. These include advanced liver fibrosis and cirrhosis, interstitial pneumonitis, severe neutropenia and pancytopenia, as well as opportunistic infections. Epstein-Barr virus-associated lymphomas have also been reported. Finally, a variety of other adverse events, such as central nervous system and cutaneous reactions, have been ascribed to methotrexate use. Numerous drug interactions may occur in patients receiving low dosage methotrexate. Most are probably not clinically significant. Conversely, methotrexate toxicity may be precipitated by concurrent use of cotrimoxazole (trimethoprim/sulfamethoxazole), probenecid, and possibly non-steroidal anti-inflammatory drugs (NSAIDs). On the basis of the available data, methotrexate should generally not be the first slow-acting antirheumatic drug to be used. However, unlike other cytotoxic agents, it should no longer be regarded as tertiary therapy for rheumatoid arthritis. Low dosage methotrexate may become one of the drugs considered earlier in the course of rheumatoid arthritis not controlled by NSAIDs alone.
TL;DR: Metyrapone treatment reduced cocaine-induced locomotor activity and relapse of cocaine self-administration, without inducing a nonspecific disruption of motor or food-directed behaviors, and confirms the involvement of glucocorticoids in the pathophysiological mechanisms underlying vulnerability to drug abuse.
TL;DR: It has been found that the accumulated sulfide is oxidized not only by the phototrophic bacteria in the sulfide oxidation zone but also by the oxygen produced by the cyanobacteria which are able to photosynthesize in the presence of sulfide.
TL;DR: There was significant discordance between the two evaluations, explained in part by the fact that the correlates of memory functioning were not related with similar strength to self reports and to actual performance.
Abstract: An epidemiological survey of self-reported memory complaints and memory performance [assessed with Benton''s visual-retention test (BVRT) and the Wechsler paired-associates test (WPAT)] was undertaken in a community sample of 2,726 noninstitutionalized subjects aged 65 and over living in Gironde (southwestern France). A significant relationship was observed between the presence of self-reported memory problems and lower performance on the BVRT and the WPAT. However, beyond this relationship, there was significant discordance between the two evaluations, explained in part by the fact that the correlates of memory functioning were not related with similar strength to self reports and to actual performance. In general, females and subjects who scored above the depressive symptomatology threshold reported more problems, while lower performances were related to older age and low educational level. The discordance between self reports and actual performance may suggest anosognosia of mild memory deficits and could possibly be a predictor of future intellectual deterioration.
01 Jul 1994-Comparative Biochemistry and Physiology Part C: Pharmacology, Toxicology and Endocrinology
TL;DR: A competitive enzyme immunoassay using 11-ketotestosterone (11-KT) covalently coupled to acetylcholinesterase (AChE) from electric eel is developed and validation of the EIA was achieved in a fish model, Siberian sturgeon.
TL;DR: The data suggest that the role of PS in massively restructuring stomatogastric output is to generate a unique motor pattern appropriate for swallowing-like behavior, and demonstrate that a neural network may not exist as a predefined entity within the CNS, but may be dynamically assembled according to changing behavioral circumstances.
Abstract: In the stomatogastric nervous system (STNS) of the lobster Homarus gammarus, the rhythmic discharge of a pair of identified modulatory neurons (PS cells) is able to construct de novo a functional network from neurons otherwise belonging to other functional networks. The PS interneurons are electrically coupled and possess endogenous oscillatory properties that can be activated synaptically by stimulation of an identified sensory pathway. PS neurons themselves project synaptically onto the three major neural networks (esophageal, gastric mill, and pyloric) of the STNS. When a PS is rhythmically active in vitro, either spontaneously (rarely) or in response to direct stimulation, it dramatically restructures the otherwise independent activity patterns of all three target networks. This functional reconfiguration elicited by a single cell does not rely on changes in neuronal allegiance to pre-existing circuits, or on a simple merger of these different circuits. Rather, PS is responsible for the creation of an entirely new motor rhythm in that, via its widespread synaptic connections, the interneuron is able to subjugate the ongoing activity of the three STNS circuits and selectively appropriate individual elements to its own intrinsic rhythm. In addition, PS excites motor neurons that innervate dilator muscles of a valve situated between the esophagus and the stomach. The reorganization of the regional foregut motor rhythms by the interneuron is therefore coordinated to the opening of this valve, which itself carries sensory receptors that have been found to activate bursting in PS. Our data suggest that the role of PS in massively restructuring stomatogastric output is to generate a unique motor pattern appropriate for swallowing-like behavior. In a wider context, moreover, the results demonstrate that a neural network may not exist as a predefined entity within the CNS, but may be dynamically assembled according to changing behavioral circumstances.
TL;DR: Reconciliation of mitochondrial permeability transition pore activity with inositol‐triphosphate‐mediated Ca2+ responses in permeabilized cells is reported and mitochondrialCa2+ spiking is reported.
TL;DR: It is shown that every oriented planar graph G = (V,A) with d-(x) ⩽ 3 for every x ϵ V has a good and semi-strong coloring using at most 4 x 5 x 24 colors.
TL;DR: The results show that suppression of corticosterone by adrenalectomy reduced the locomotor response to cocaine and morphine, injected both systemically and centrally.
Abstract: Studies of intravenous self-administration and psychomotor effects of drugs have recently suggested that stress-induced corticosterone secretion may be an important factor determining vulnerability to drugs of abuse. In this report, we studied if basal physiological corticosterone secretion modulates sensitivity to cocaine and morphine, and if changes in the reactivity of mesolimbic dopaminergic (DA) neurons, one of the principal substrates of drug-reinforcing effects, are involved. For this purpose we determined the psychomotor effects of these drugs in animals in which corticosterone secretion was suppressed by adrenalectomy and in adrenalectomized animals submitted to different corticosterone replacement therapies designed to mimic (1) only the diurnal levels of the hormone, obtained by the subcutaneous implantation of 50 mg corticosterone pellets; (2) only the nocturnal levels, obtained by adding corticosterone (50 micrograms/ml) to the drinking solution during the dark period; and (3) the entire circadian fluctuation, obtained by combining the two previous treatments. Locomotor response to cocaine and morphine was studied after both systemic and central injections, into the nucleus accumbens for cocaine and into the ventral tegmental area for morphine. These sites were chosen because stimulant effects of cocaine and morphine injected in these structures are dopamine dependent. Our results show that suppression of corticosterone by adrenalectomy reduced the locomotor response to cocaine and morphine, injected both systemically and centrally. The reinstatement of diurnal levels of corticosterone totally reversed adrenalectomy's effects on the behavioral response to cocaine, whereas the reestablishment of the entire corticosterone circadian fluctuation (diurnal plus nocturnal levels) was necessary to reverse the response to morphine.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: This work shows that association of doxorubicin with nanoparticles could provide a useful tool for circumventing multidrug resistance, probably by a bypass of P-glycoprotein rather than by an inhibition of this pump.
TL;DR: The catalytic capacity of several excreted pectinolytic enzymes obtained from various yeast strains was examined using in vivo and biochemical techniques and Saccharomyces cerevisiae was identified as SCPP, which allows pectin hydrolysis during cell growth.
Abstract: The catalytic capacity of several excreted pectinolytic enzymes obtained from various yeast strains was examined using in vivo and biochemical techniques. Of the 33 yeast strains studied, 30 were isolated from champagne wine during alcoholic fermentation. Only one yeast strain was found to excrete pectinolytic enzymes and was identified as Saccharomyces cerevisiae and designated SCPP. Pulsed-field gel electrophoresis and the polymerase chain reaction technique were used to characterize further this specific strain. Three types of pectinolytic enzymes were found to be excreted by SCPP: polygalacturonase, pectin-lyase and pectin-esterase. These enzymes allow pectin hydrolysis during cell growth.
TL;DR: Results clearly demonstrate that Leuc.
Abstract: Populations of Leuconostoc oenos were harvested from wines containing a relatively high concentration of biogenic amines. Cultivation of the biomass in synthetic media and wine showed that it consisted of histamine-producing strains. Histamine levels after culture depended on the quantity of precursor available and on the presence of yeast lees, which certainly enriched the medium in histidine. Ethanol and pH, which control bacterial growth rate and total population, were also significant factors: pH and low ethanol concentration enhanced histamine production. Strain Leuc. oenos 9204 was isolated and studied since it retained its ability to produce histamine after several transfers. In synthetic medium this strain produced large amounts of histamine especially in the poorest nutritional conditions (no glucose, no L-malic acid). These results clearly demonstrate that Leuc. oenos involved in wine-making might play a role in biogenic amine production. The vinification method might also influence the final amine concentration in wine.
Katholieke Universiteit Leuven1, Royal College of Surgeons in Ireland2, University of Münster3, Université libre de Bruxelles4, Joseph Fourier University5, University of Bordeaux6, Nagoya University7, NewYork–Presbyterian Hospital8, Kyushu University9, National University of Cordoba10, Lund University11, Peking Union Medical College12, University of Padua13, Ludwig Maximilian University of Munich14, University of Milan15, Duke University16, Mayo Clinic17
TL;DR: An operational threshold for making clinical decisions based on ambulatory blood pressure (ABP) measurement is delineated by studying the ABP in subjects who were diagnosed as either normotensive or hypertensive by conventional blood pressure measurement.
Abstract: Objective: To delineate more precisely an operational threshold for making clinical decisions based on ambulatory blood pressure (ABP) measurement by studying the ABP in subjects who were diagnosed as either normotensive or hypertensive by conventional blood pressure (CBP) measurement. Subjects: Twenty-four research groups recruited 7069 subjects. Of these, 4577 were normotensive (CBP 160 mmHg) and 1310 had diastolic hypertension (diastolic CBP >95 mmHg). Combined systolic and diastolic hypertension was present in 861 subjects. Hypertension had been diagnosed from the mean of two to nine (median two) CBP measurements obtained at one to three (median two) visits. Results: The 95th centiles of the ABP distributions in the normotensive subjects were (systolic and diastolic, respectively) 133 and 82 mmHg for 24-h ABP, 140 and 88 mmHg for daytime ABP and 125 and 76 mmHg for night-time ABP, respectively. Of the subjects with systolic hypertension, 24% had 24-h systolic ABP
TL;DR: In this article, the mid-infrared spectra of monolayers spread at the air-water interface have been obtained, completely devoid of strong water vapor absorptions, using polarization modulation infrared reflexion absorption spectroscopy (PM-IRRAS).
TL;DR: It is shown experimentally that an inhibition of cytochrome c oxidase activity by cyanide, simulating a defect in this step, leads to a decrease in mitochondrial respiration which exhibits a threshold behaviour similar to that observed in mitochondrial diseases.
Abstract: Threshold effects in the expression of metabolic diseases have often been observed in mitochondrial pathologies, i.e. the clinical demonstration of the disease appears only when the activity of a step has been reduced to a rather low level. We show experimentally that an inhibition of cytochrome c oxidase activity by cyanide, simulating a defect in this step, leads to a decrease in mitochondrial respiration which then exhibits a threshold behaviour similar to that observed in mitochondrial diseases. We discuss this behaviour in terms of metabolic control theory and construct a mathematical model simulating this behaviour.
TL;DR: In this article, a simple way to get the main parameters of a tip -its apex radius of curvature and the cone angle -by using a simple reference sample: latex balls is provided.
TL;DR: In this article, the open boundary conditions for the incompressible Navier-Stokes equations are given from a weak formulation in velocity-pressure variables, and some natural boundary conditions involving the traction or pseudotraction and inertial terms are established.
Abstract: SUMMARY The aim of this paper is to give open boundary conditions for the incompressible Navier-Stokes equations. From a weak formulation in velocity-pressure variables, some natural boundary conditions involving the traction or pseudotraction and inertial terms are established. Numerical experiments on the flow behind a cylinder show the efficiency of these conditions, which convey properly the vortices downstream. Comparisons with other boundary conditions for the velocity and pressure are also performed.
TL;DR: A high degree of potential for plasticity is established in the development of the human bicondylar angle and the direct association of a bipedal locomotion and (especially) posture with the developmental emergence of a human femoral bicONDylar angles is established.
Abstract: The presence of a femoral bicondylar angle consistently and significantly greater than 0" has been a hallmark of hominid bipedality, but its pattern of development has not been documented. We have therefore compiled cross-sectional data on the development of the articular bicondylar angle for a clinical sample of modern humans and of the metaphyseal bicondy- lar angle for two Recent human skeletal samples, one predominantly Euro- pean in origin and the other Amerindian. All three samples exhibit a pattern of a bicondylar angle of 0" at birth and then a steady average increase in the angle from late in the first year postnatal, through infancy, and into the juvenile years. The two skeletal samples reach low adult values by approxi- mately 4 years postnatal, whereas the clinical sample with a lowered activity level appears to attain consistent adult values slightly later (approximately 6 years postnatal). In addition, two modern human individuals, one nonambu- latory and the other minimally ambulatory, show no and little development, respectively, of a bicondylar angle. These data, in conjunction with clinical and experimental observations on the potential and form of angular changes during epiphyseal growth, establish a high degree of potential for plasticity in the development of the human bicondylar angle and the direct association of a bipedal locomotion and (especially) posture with the developmental emer- gence of a human femoral bicondylar angle. o 1994 Wiley-Liss, Inc.