A joint coordinate system proposal for the study of the trapeziometacarpal joint kinematics.

The International Society of Biomechanics (ISB) has recommended a standardisation for the motion reporting of almost all human joints. This study proposes an adaptation for the trapeziometacarpal joint. The definition of the segment coordinate system of both trapezium and first metacarpal is based on functional anatomy. The definition of the joint coordinate system (JCS) is guided by the two degrees of freedom of the joint, i.e. flexion-extension about a trapezium axis and abduction-adduction about a first metacarpal axis. The rotations obtained using three methods are compared on the same data: the fixed axes sequence proposed by Cooney et al., the mobile axes sequence proposed by the ISB and our alternative mobile axes sequence. The rotation amplitudes show a difference of 9 degrees in flexion-extension, 2 degrees in abduction-adduction and 13 degrees in internal-external rotation. This study emphasizes the importance of adapting the JCS to the functional anatomy of each particular joint.

[How to define the joint movements unambiguously: proposal of standardization for the trapezometacarpal joint]. / Comment définir sans ambiguïté les mouvements d'une articulation: proposition de standardisation pour l'articulation trapézométacarpienne.

In order to define the movements of a joint, clinicians usually use anatomic terms. These terms are clearly understandable for a simple movement, defined in an anatomic plane. However, these terms are ambiguous for complex movements or for movements out of an anatomic plane. This, for instance, is the case for the internal-external axial rotation of the trapezometacarpal joint. For the study of complex movements, engineers preferentially use methods such as Euler angles, which correspond to three angles about three axes chosen in a defined order or sequence. Thus, the International Society of Biomechanics has proposed a joint coordinate system definition where every axis is associated with a functional degree of freedom of the joint. The first and third axes are embedded in the proximal and distal segments whilst the second axis, called the "floating" axis, is always orthogonal to the other two. The present work deals with the application of this concept to the trapezometacarpal joint. The two principal degrees of freedom, of flexion-extension and of abduction-adduction are defined following classical anatomical axes of respectively the trapezium and first metacarpal. Conversely, internal-external axial rotation is defined about the "floating" axis which does not have anatomical definition but can be geometrically deduced from the two others.

The duration of the antibody response to meningococcal vaccination in an African village.

Sera were obtained from 119 Nigerian villagers two years after immunization with group A and group C meningococcal polysaccharide vaccines. Measurement of meningococcal antibody levels in individual serum samples by the haemagglutination technique showed that two years after vaccination the mean group A meningococcal antibody level was no higher in immunized subjects than in 140 age-matched, non-immunized controls. Over-all the mean group C meningococcal haemagglutinating antibody level was significantly higher in immunized subjects than it was in controls but this difference was not found in those under the age of 15 years at the time of vaccination. However, when pooled serum samples from the same subjects were tested for meningococcal antibodies by radioimmunoassay, immunized subjects were found to have significantly higher mean levels of both group A and group C meningococcal antibodies than the controls. The possible reasons for this discrepancy are considered and the significance of these findings in relation to plans for mass immunization with meningococcal vaccines in tropical Africa are discussed.

Three-dimensional modelling of the motion range of axial rotation of the upper arm.

Computer simulation of human movements and postures suffers generally from the lack of reliable data, such as data on joint limits. In this paper, the motion range of axial rotation of the upper arm was investigated. An original surface regression fitting method using an orthogonal homogeneous polynomial basis has been presented. The method was used to fit both maximum internal and external upper arm axial rotation surfaces based on the experimental data from seven male subjects of ages 23-34. Under the assumption of normal distribution, the sample mean and the confidence limits for population mean of both internal and external upper arm axial rotation limits were derived. It has been shown that the axial motion range of the upper arm depends strongly on the position of the upper arm in the shoulder sinus cone and varies on average from 94 to 157 degrees. The present work can be considered as an extension of the shoulder kinematic data base established by Engin and Chen (1986), Journal of Biomechanical Engineering 108, 215-221.

Response to tetanus immunization in onchocerciasis patients.

Fifty-five people were examined for tetanus antitoxin level two months after immunization with a single 0.5 ml dose of concentrated tetanus toxoid vaccine; only 7.1% of patients infected with onchocerciasis became immunized, whereas 44.5% were immunized in the control group. These results are consistent with previous observations of a reduced level of both cell-mediated and humoral immunity in patients heavily infected with parasitic diseases, especially onchocerciasis. This study raises doubts about the efficacy of immunization in young adult age groups and re-emphasizes the need for immunization in infancy.

[Serological evaluation of an antimeningococcal mass vaccination campaign in Niger]. / Evaluation sérologique d'une campagne de vaccination antiméningococcique de masse au Niger.

Authors searched by mean of radio-immuno-essay A and C anti-meningococcal antibodies in two villages from Niger (181 and 92 patients) in a meningitidis endemic area, which one profited 10 months ago of a mass vaccination campaign (A and C polysaccharides). A and C antibodies quantities and percentages of protected patients are not significantly different between the two villages. In one hand anti-C levels increase with patients age. In the other hand, there is a correlation between C meningococcal antibodies and anti-Hbc antibodies.

Combination of attenuated measles vaccine (Schwarz) with meningococcus A and A + C vaccine.

There is an obvious interest in a combined meningococcus-measles vaccine since the two diseases are widespread and serious in Third World countries among children under five years of age. The purpose of our study was to show the safety and effectiveness of such a combined preparation. The study covered 110 children between 8 months and 4 years of age who were followed systematically in a maternal child health center in the Paris area. Only 93 of them were checked before and after the immunization. The serologic titrations by the hemagglutination assay (IHA) for measles, and by radioimmunological assay (RIA) for meningococcus A and C showed that the Schwarz strain measles vaccine combined with meningococcus A or the association A+C does not interfere with the increase of A or C titers. 100% of the children showed a seroconversion equal to or less than 2 micrograms per ml, in the case of meningococcus A, as well as for C, regardless of age. Furthermore, 88% of the subjects showed a titer greater than or equal to 4 micrograms for the meningococcus A and 79% for C. On the other hand, meningococcus A or the association A+C seem to depress measles vaccine activity. Nevertheless, more than 80% of the children tested showed seroconversion when the measles vaccine was combined with meningococcus A, and only 69% when combined with meningococcus A and C.

Antibodies to meningococcus polysaccharides in nonspecific gamma-globulins from different regions of the world.

Seventy-one batches of nonspecific gamma-globulin obtained from France, USSR and Mongolia were studied for presence of specific antibody to group A and C meningococcus polysaccharide. Specific activity was tested by two methods: radioimmunoassay (Lyon) and reaction of passive haemagglutination inhibition (Moscow). Antibodies were detected in all the gamma-globulin batches tested, in some of them at high titres. The summary results indicated that approximately equal levels of specific A antibodies were present in preparations obtained from the different regions of the world. Antibodies to group C polysaccharide showed considerable variation in level from selection country to country; the highest level of C antibodies was in gamma-globulin from France. The authors feel entitled by the results to recommend testing of nonspecific gamma-globulin, selection of batches with a high level of specific antimeningococcus antibodies, and their judicious use.