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At least 1,153 records · Page 64Linked to original sources
PubMed1997

[Etiologic aspects of nephrotic syndrome in Black African adults in a hospital setting in Abidjan].

We studied nephrotic patients hospitalised in internal medicine service at Treichville Teaching hospital from September 1986 to February 1993 for precising the aetiological aspects of black adult patients and their evolutive biological, clinical and epidemiological profile. Secondary Nephrotic syndrome represented 18% of the whole patients with Nephrotic syndrome hospitalised during the same period. In aetiological field it was about: diabetic nephropathy 11 cases (33%); lupus nephritis 7 cases (21%); renal amyloidosis 5 cases (15%); HIV nephropathy 5 cases (15%); schistosomiasis nephrotic syndrome 1 case (3%); pregnancy nephrotic syndrome 1 case (3%); cryoglobulinemia 1 case (3%); malignancy nephrotic syndrome 1 case (3%); nephrosclerosis 1 case (3%).

Acquired Immunodeficiency Syndrome↗
PubMed1998

[MRI symptomatology of non-tumoral myelopathies].

We present a retrospective study in order to analyze the abnormalities noted on MRI in 27 cases of myelopathy excluding tumors, explored between 1994 and 1996. The different lesions were: Multiple Sclerosis (n = 11), Spondylotic myelopathy (n = 3), Neurosarcoidosis (n = 4), CMV Myelitis (n = 1), Radiation Myelopathy (n = 1), Spinal Dural Arteriovenous Fistula (n = 1), Intramedullary Cysticercosis (n = 1), Infarct (n = 5). The exams have been made on 1.5 Tesla Magnetom Vision Siemens or GE Signa machine. All patients have had axial and sagittal views with coronal complementary study in 4 cases. Sequences were Spin echo pT1 (TR: 560, TE: 12), Fast Spin echo pT2 (TR: 3 500, TE: 99 or 128), and gradient echo pT2 (TR: 700, TE: 22, Angle: 25 degrees). Intravenous injection of Gadolinium has been made in 16 cases (0.1 mmol/kg). We have studied the presence or not of a signal abnormality in pT1 and/or in pT2, of enhancement, and its topography (cervical, thoracic, lumbar). We classified lesions in central and/or peripheral and according, to their topography in anterior, posterior or lateral type. The form has been classified in four types (nodular, triangular, "pen like", plage). Extension in transversal (superior or inferior to half medullary surface) and cranio-caudal directions (inferior to one vertebrae, between one and two vertebrae, superior to two vertebrae) has been also classified. Others intra or perimedullar and encephalic abnormalities have been noted. We analyzed the results for each pathology and underline the essential diagnosis criteria noted (low cranio-caudal and transversal extension with frequent triangular form of Multiple Sclerosis lesions, frequent suggestive abnormalities of the encephale (82%) in Multiple Sclerosis, intra and perimedullar enhancement with deformations of the surface of the spinal cord in Sarcoidosis' lesions, extended dorsolumbar "pen like" lesions with inconstant enhancement of infarcts, focal plage lesions centered on degenerative changes of the spinal canal in spondylotic myelopathy, bony lipomatous involution in front of intramedullary radiation plage lesion...) and also review the literature and confront their results to it. We insist on the difficulties in classifying myelopathy (radio-clinical terminology discordances, identical signal abnormalities frequently caused by different illness, necessity to compare to pathologic results). We propose a MRI study protocol that should interest the whole spinal cord and comport T1 weighted without and after gadolinium sequences, T2 weighted sequences (with always a gradient echo type). 2 or better 3 different plans should be made. A complementary study of the brain by MRI is often useful. Clinical study, biology, evolution, MRI and when possible pathology all are necessary to better understand myelopathy's mechanisms.

Adolescent↗
PubMed1998

Primary chondrosarcoma of long bones and limb girdles.

BACKGROUND: Chondrosarcomas are common solid malignant tumors of bone, second in incidence only to osteosarcomas. The biologic evolution of chondrosarcomas is slow, requiring long follow-up intervals for meaningful survival analysis. METHODS: This study describes the clinicopathologic profiles of 344 patients, 194 male and 150 female (M:F, 1.3:1.0), with primary chondrosarcoma of long bones and limb girdles seen at 1 institution over a period of 80 years. RESULTS: The average age at presentation was 46 years (range, 5-82 years). The pelvis was the most common location (1.7% of all patients). Local pain was the most frequently reported initial symptom (81.4%). Survival analysis was limited to 233 patients whose primary treatment was given at the Mayo Clinic. All 233 patients had potential follow-up of at least 5 years. The overall 5-year survival rate was 77% (the expected rate was 96%). Local recurrence developed in 19.7% of patients and metastatic lesions in 13.7%. The recurrence rate was higher for tumors of the shoulder and pelvis than for tumors of long bones. Radiographically, chondrosarcomas had a characteristic appearance, including a combination of bone expansion and cortical thickening. Entering the tumor at surgery increased the risk of local recurrence. Histologic tumor grade was an important predictor of local recurrence and metastasis. CONCLUSIONS: With adequate initial surgical intervention, chondrosarcoma is primarily a local disease with a low metastatic rate.

Adolescent↗
PubMedDate not supplied

The bdr gene families of the Lyme disease and relapsing fever spirochetes: potential influence on biology, pathogenesis, and evolution.

Species of the genus Borrelia cause human and animal infections, including Lyme disease, relapsing fever, and epizootic bovine abortion. The borrelial genome is unique among bacterial genomes in that it is composed of a linear chromosome and a series of linear and circular plasmids. The plasmids exhibit significant genetic redundancy and carry 175 paralogous gene families, most of unknown function. Homologous alleles on different plasmids could influence the organization and evolution of the Borrelia genome by serving as foci for interplasmid homologous recombination. The plasmid-carried Borrelia direct repeat (bdr) gene family encodes polymorphic, acidic proteins with putative phosphorylation sites and transmembrane domains. These proteins may play regulatory roles in Borrelia. We describe recent progress in the characterization of the Borrelia bdr genes and discuss the possible influence of this gene family on the biology, pathogenesis, and evolution of the Borrelia genome.

Abortion, Veterinary↗
PubMedDate not supplied

[The evolutionarily optimal rates of body development. The age of onset of sexual maturity and species-specific longevity as the parameters optimized during evolution].

Dynamics of biological community of the "resource--consumer" type considering age structure of consumer population is described by a system of differential equations with special derivatives. On the basis of such a model, a competition model for non-crossing populations with different individual development rates is elaborated. It is shown that only a population with development rates maximizing the Malthusian function (reaching zero value at the equilibrium state of the system) is able to survive under competition for food resources. Equilibrium density of the resources is provided being minimal. Thus maximum energy influx into the population is gained. Search algorithm of evolutionary values of puberty, age and maximal longevity of individuals belonging to the consumer population is proposed. Analytic dependence of maximal longevity on environmental factors and some other parameters are found. Aging is considered to be mechanism leading to death while individual approaches evolutionary optimal longevity.

Animals↗
PubMed2002

At the boundary between biological and cultural evolution: the origin of surname distributions.

Surnames and non-recombining alleles are inherited from a single parent in a highly similar way. A simple birth-death model with mutations can accurately describe this process. Exponentially growing and constant populations are investigated, and we study how different compositions of the founder populations can be observed in present-day diversity distributions. We analyse different quantities in the statistically stationary state, both through analytic and numerical methods. Our results compare favourably to field data for family sizes in several countries. We discuss the relationship between the distribution of surnames and the genetic diversity of a population.

Biological Evolution↗
PubMed1989

Biological and genetic evolution of the nucleoprotein gene of human influenza A viruses.

There is a significant difference in the ability of human influenza A virus H1N1 strains isolated up to 1977 and those isolated later to rescue temperature-sensitive mutants of fowl plague virus with a defect in the nucleoprotein (NP) gene. Therefore the NP genes of five human H1N1 and H3N2 influenza A virus strains, isolated between 1950 and 1978, have been sequenced. By comparison with previous and more recent isolates, an evolutionary pathway has been established. Three amino acid replacements were found which might be responsible for the functional difference between the USSR (1977) and the Brazil (1978) strains. The California (H1N1) strain isolated in 1978 had acquired by reassortment the NP gene of a human H3N2 virus circulating at about 1977 as had been previously suggested by investigations involving RNase fingerprint or hybridization techniques.

Amino Acid Sequence↗
PubMed2004

Flaked stones and old bones: biological and cultural evolution at the dawn of technology.

The appearance of Oldowan sites ca. 2.6 million years ago (Ma) may reflect one of the most important adaptive shifts in human evolution. Stone artifact manufacture, large mammal butchery, and novel transport and discard behaviors led to the accumulation of the first recognized archaeological debris. The appearance of the Oldowan sites coincides with generally cooler, drier, and more variable climatic conditions across Africa, probably resulting in a net decrease in woodland foods and an increase in large mammal biomass compared to the early and middle Pliocene. Shifts in plant food resource availability may have provided the stimulus for incorporating new foods into the diet, including meat from scavenged carcasses butchered with stone tools. Oldowan artifact form varies with clast size, shape, raw material physical properties, and flaking intensity. Oldowan hominins preferred hard raw materials with good fracture characteristics. Habitual stone transport is evident from technological analysis, and raw material sourcing to date suggests that stone was rarely moved more than 2-3 km from source. Oldowan debris accumulation was spatially redundant, reflecting recurrent visitation of attractive points on the landscape. Thin archaeological horizons from Bed I Olduvai Gorge, Tanzania, were probably formed and buried in less than 10 years and document hominin processing of multiple carcasses per year. Transport beyond simple refuging behavior is suggested by faunal density at some site levels. By 2.0 Ma, hominin rank within the predatory guild may have been moderately high, as they probably accessed meaty carcasses through hunting and confrontational scavenging, and hominin-carnivore competition appears minimal at some sites. It is likely that both Homo habilis sensu stricto and early African H. erectus made Oldowan tools. H. habilis sensu stricto was more encephalized than Australopithecus and may foreshadow H. erectus in lower limb elongation and some thermoregulatory adaptations to hot, dry climatic conditions. H. erectus was large and wide-ranging, had a high total energy expenditure, and required a high-quality diet. Reconstruction of H. erectus reproductive energetics and socioeconomic organization suggests that reproductively active females received assistance from other group members. This inference, combined with archaeological evidence for acquisition of meaty carcasses, suggests that meat would have been a shared food. This is indirectly confirmed by nutritional analysis suggesting that the combination of meat and nutritionally dense plant foods was the likely diet fueling body size increase and encephelization in Homo. Most discussion of Oldowan hominin behavior and ecology, including that presented here, is based on materials from a few sites. There is a critical need to analyze additional large, primary-context lithic and faunal assemblages to better assess temporal, geographic, and environmental variability in Oldowan behavior.

Adaptation, Physiological↗
PubMedDate not supplied

Clinico-biologic aspects and evolutive tendencies in sacroiliitis.

A group of 103 patients with radiologic changes of sacroiliitis were investigated and followed up over a mean period of 3.5 years. The biologic explorations (nonspecific inflammatory tests, humoral immunologic determinations and serum fibronectin assay) as well as sacroiliac and spine radiographic examinations, were repeated every 6th-12th months. In 32 patients (31%) clinical, biologic and radiologic signs of evolutive disease, were detected. In such cases, sacroiliitis representing in fact a form of onset of ankylosing spondylitis, the HLA-B27 phenotype was also determined and was found present in 8 cases. Of the biologic tests the decrease of serum fibronectin proved the most significantly correlated with evolutive tendency of sacroiliitis.

Adult↗