Epidemiology and features of knee osteoarthritis in the Ivory Coast

We retrospectively studied 369 cases of knee osteoarthritis in 240 patients seen at the Cocody Teaching Hospital in Abidjan, Ivory Coast, from November 1984 through March 1989. There were 126 cases (34.14%) of patellofemoral osteoarthritis, 104 cases (28.18%) of femorotibial osteoarthritis and 139 cases (37.66%) of global knee osteoarthritis (defined as patellofemoral and femorotibial osteoarthritis in the same joint). There was a marked female bias (80.42% of patients). Onset was earlier in patellofemoral osteoarthritis (51.25 years) than in femorotibial osteoarthritis (57.85 years). Half the patients (51.25%) were housewives. The Akan and Mandé ethnic groups contributed 61.54% and 33.03% of patients, respectively. Obesity was present in 19.04% of cases of patellofemoral osteoarthritis and in 10.57% of cases of femorotibial osteoarthritis. Of the patients with femorotibial osteoarthritis, 20.20% had a history of arthritis of the knee and of those with global knee osteoarthritis, 12.23% reported a prior injury to the knee. Varus deformity was found in 24.03% and valgus deformity in 19.23% of the patients with femorotibial osteoarthritis.     

Boson analyses in the Ge isotopes

The renin-angiotensin system is activated during vascular development and injury. Furthermore, angiotensin II (Ang II) is a comitogen for fetal mesangial cells in vitro and it may be important in vascular smooth cell growth in disease states. Since fibronectin is an important extracellular matrix protein for vascular development and it too is overexpressed in the mesangium of diseased glomeruli, we explored the interrelationship of fibronectin and Ang II in fetal mesangial cell growth. In human fetal kidney, Ang II type 2 receptors (AT2) were detected in abundance by ex vivo autoradiography. When mesangial cells were isolated from fetal kidney and grown in culture, Ang II type 1 receptors (AT1) were also detected. To explore the mitogenic properties Ang II and fibronectin as well as the effects of Ang II on fibronectin metabolism, studies were performed in vitro, isolated from the potentially confounding variables of hemodynamic influence and circulating growth factors and cytokines. In vitro, mesangial cells expressed a single class of AT1 receptors that were not altered by growth on various substrates. Ang II (10(-7) M) significantly increased thymidine incorporation by confluent human fetal mesangial cells (twofold). When subconfluent, Ang II-stimulated proliferation was greater (fourfold). Ang II significantly increased cell-associated and secreted fibronectin as determined by immunoprecipitation at concentrations that also stimulate mitogenesis. Both of these Ang II-mediated responses were inhibited by the AT1 receptor antagonist DuP-753 (10(-5) M) but not by AT2 receptor antagonist.(ABSTRACT TRUNCATED AT 250 WORDS)     

Isolation and structure/activity features of halomon-related antitumor monoterpenes from the red alga Portieria hornemannii

Ten halogenated monoterpenes (2-6 and 8-12) related to the novel antitumor compound halomon (1) or to the carbocyclic analog 7 have been isolated from different geographic collections of the red alga, Portieria hornemannii. Structures were assigned to the basis of spectral analyses (primarily NMR and MS). The absolute configuration of isohalomon (2) was further established by X-ray crystallography. The compounds were comparatively evaluated alongside 1 and 7 in the U.S. National Cancer Institute's in vitro human tumor cell line screening panel. The results provide some interesting initial insights into the structure/activity relationships in this series.     

The role of imaging techniques in stress testing

The addition of various cardiac imaging techniques to standard ECG stress testing has permitted enhanced diagnostic capability in the evaluation of patients with suspected coronary artery disease. In addition, the prognostic and pathophysiologic information provided by such imaging modalities has given us insight not previously available by standard stress testing alone. This has been helpful in guiding management decisions in patients with known coronary artery disease. The modalities include myocardial perfusion imaging, stress echocardiography, and radionuclide ventriculography. These techniques can provide complementing and unique information in the evaluation of myocardial blood flow, function, and viability.     

Postnatal maturation of the layer III pyramidal neurons in the human prefrontal cortex: a quantitative Golgi analysis

In this study we examined the morphological maturation of the basal dendritic field of layer III pyramidal neurons located in the human dorsolateral prefrontal cortex in subjects ranging from 7.5 months after birth up to 27 years. The sections were stained with the Golgi-Cox method and the three-dimensional branching pattern was measured with a semi-automatic dendrite measuring system. Results show a rapid growth phase of the dendritic field from 7.5 months after birth up to one year. A marked increase in total dendritic length is observed, for which elongation of the terminal segments, longer intermediate segments and an increase in number of segments is an explanation. The dendritic length appears to have stabilized after one year, leading us to conclude that the postnatal morphological maturation of the layer III pyramidals does not continue well into childhood, but is completed at a much younger age. Additionally we analyzed the effect of varying section thickness on dendritic parameters and found no tendency for higher dendritic values with increasing section thickness for the range of thickness values of the histological sections used.     

Textural and microstructural gradient effects on the mechanical behavior of a tantalum plate

The effects of gradients in the texture and microstructure of a tantalum plate on mechanical behavior are examined. In particular, the effects of variations in grain size and texture from the surface of the plate to the centerline on the yield behavior and final shape of compression samples are investigated. Individual lattice orientations were measured on samples both before and after deformation using automatic analysis of electron backscatter diffraction patterns. These data were used as input to a polycrystal plasticity model based on the Taylor assumption of uniform strain. Results are compared from experimental and simulated compression tests. The effects of the texture and grain size gradients on these results are discussed. The influence of the texture gradient was found to be the dominating factor controlling the nonuniform plastic response of the material. This work also demonstrates the capability of currently available tools for characterizing inhomogeneous microstructures and modeling the effects of variations in texture and microstructure on mechanical behavior.     

Three-dimensional, finite deformation, viscoplastic constitutive models for polymeric materials

A general methodology for developing three-dimensional. finite deformation, viscoplastic constitutive models for polymeric materials is presented. The development begins with the presentation of a one-dimensional spring and dashpot construction which exhibits behavior typical of polymeric materials, namely strain-rate dependence, stress relaxation, and creep. The one-dimensional construction serves as a starting point for the development of a three-dimensional, finite deformation, viscoplastic constitutive model which also exhibits typical polymeric behavior. Furthermore, the three-dimensional constitutive model may be easily generalized to incorporate an arbitrary number of inelastic processes, representing (inelastic) microstructural deformation mechanisms operating on different time scales. Strain-rate dependence, stress relaxation, and creep phenomena are discussed in detail for a simple version of the constitutive model. Test data for a particular polymer is used to validate the simple model. It is concluded that the methodology provides a flexible approach to modeling polymeric materials over a wide range of loading conditions.     

Transverse tripolar stimulation of peripheral nerve: a modelling study of spatial selectivity

Nocturnal incontinence (enuresis) affects 20% of children over four years old, and this figure typically decreases by 15% each year. At the age of 18, 1% of those people remain enuretic. Nocturnal enuresis can be treated by means of a conditioning device that awakens the patient once the urine level has reached a preestablished threshold of the capacity of his or her bladder. We have designed and implemented a portable miniaturized ultrasonic monitor, which permits estimation of the urine volume with an accuracy of 75%. Prototypes have been completed and validated on 41 patients (children) at Ste. Justine Hospital (Montréal). On the first group of 33 patients, we used a hand-held transducer to determine the volume detection range, which is accurate for volumes between 40 and 400 mL. With the second group of 8 patients, the device was mounted on an elastic belt around the abdomen. Measurements were taken in order to validate the accuracy of urine threshold detection and the activation of the corresponding alarm.     

Modulation of human microvascular endothelial cell bioenergetic status and glutathione levels during proliferative and differentiated growth

During angiogenesis, formerly differentiated human microvascular endothelial cells (HMECs) return to a proliferative growth state. Many fundamental questions regarding HMEC function, such as how HMECs adapt to changes in bioenergetic requirements upon return to proliferative growth, remained unanswered. In this study, we evaluated whether modifications in HMEC bioenergetic profiles and glutathione (GSH) levels accompanied the cellular transition between differentiated and proliferative growth. To provide insight into the continuum of cellular adaptations that occur during this transition, we used a method recently developed in our laboratory that induces a state of morphological and functional predifferentiation in HMECs. Cellular morphology, in conjunction with flow cytometric DNA analyses and HMEC functional assays (the directed migration and intercellular association involved in microtubule formation) were employed to validate the HMEC culture state of growth. Analysis of the HPLC nucleotide profiles disclosed several findings common to all culture growth states. These uniform findings, e.g., cellular energy charges > 0.90, and highly reduced redox states, revealed that cultured HMECs maintain high rates of oxidative metabolism. However, there were also significant, culture growth state related differences in the nucleotide profiles. Proliferative HMECs were shown to possess significantly higher (relative to both large vessel endothelial cells, and differentiated HMECs) levels of GSH and specific nucleotides which were related with a return to the active cell cycle-ATP, GTP, UTP, and CTP, and NADPH. Further, the nucleotide profiles and GSH levels of the predifferentiated HMECs were determined to be intermediate between levels obtained for the proliferative and differentiated HMECs. The results of this study demonstrate that the capacity to modulate their cellular bioenergetic status during growth state transitions is one of the adaptations that enable HMECs to retain a growth state reciprocity. In addition, our findings also show that HMECs, especially during the proliferative growth state, are biochemically distinct from endothelial cells harvested from large vessels, and therefore suggest that HMECs are the cells of choice to employ when studying diseases that affect the human microvasculature.