Simplified two-stage below-knee amputation for unsalvageable diabetic foot infections

A simplified two-stage below-knee amputation for unsalvageable diabetic foot infections was done on 19 limbs with 84% good results for healing. The first stage was the standard below-knee amputation with a long posterior flap in which the fascia and skin were closed in the central portion with the medial and lateral portions of the wound left open for drainage. The second stage was delayed until closure of the open wounds three to seven days after the first stage. Wagner's classification of diabetic foot lesions was used to stratify these cases. Grades 3 and 4 foot infections had a uniformly good prognosis for healing with this surgical technique. Grade 5 foot infections had a poor prognosis for healing, especially if associated with renal failure and dialysis, even with an initial guillotine amputation.     

Cranial sutures and craniometric points detected on MRI

The main goal of the study was to determine on MRI the cranial sutures, the craniometric points and craniometric measurements, and to correlate these results with classical anthropometric measurements. For this purpose, we reviewed 150 cerebral MRI examinations considered as normal (Caucasian population aged 2049 years). For each examination we individualized 11 craniometric landmarks (Glabella, Bregma, Lambda, Opisthocranion, Opisthion, Basion, Inion, Porion, Infra-orbital, Eurion) and three measurements. Measurements were also calculated independently on 498 dry crania (Microscribe 3-DX digitizer). To validate the MRI procedure, we measured four dry crania by MRI and with compass or digital caliper gauges. Cranial sutures always appeared without signal (black), whatever the MRI sequence used, and they are better visualized with a 5 mm slice thickness (compact bone overlapping). Slice dynamic analysis and multiplanar reformatting allowed the detection of all craniometric points, some of these being more difficult to detect than others (Porion, Infra-orbital). The measurements determined by these points were as follows: VertexBasion height=135.66±6.56 mm; EurionEurion width=141.17±5.19 mm; GlabellaOpisthocranion length=181.94±6.40 mm. On the midline T1-weighted sagittal image, all median craniometric landmarks can be individualized and the GlabellaOpisthocranion length, VertexBasion height and parenchyma indices can be calculated. Craniometric points and measurements between these points can be estimated with a standard cerebral MRI examination, with results that are similar to anthropometric data.     

Developmental connections between cranial components and the emergence of the first permanent molar in humans

The age of emergence of the first molar (M1) is a developmental event correlated with many variables of primate life history, such as adult brain size. The evolution of human life history is characterized by the inclusion of childhood, which takes place between weaning and M1 emergence. Children still depend on adults for nutrition due to their small digestive system and their immature brains. By contrast, juveniles are not dependent because of M1 emergence, which enables shifting to adult type diet, and attainment of nearly adult brain size. In this study, developmental connections between M1 emergence and growth of cranial components were explored in two ways in order to understand the developmental basis of their evolutionary connections: (1) differences in growth trajectories of cranial components with respect to M1 emergence and (2) differences between individuals with and without fully emerged M1. Growth of anteroneural, midneural, posteroneural, otic, optic, respiratory, masticatory and alveolar cranial components was analysed in human skulls of individuals aged 0-20 years and in an adult reference skull. Volumetric indices were calculated to estimate size. Two subsamples were selected in order to focus on the transition between deciduous and permanent dentition: those with full deciduous dentition and before M1 reaches the occlusal plane; and those who present M1 in full emergence and no other cheek-tooth at the occlusal plane. The principal results were as follows. (1) Trajectories fitted using the whole sample are characterized by an inflection point that takes place before M1 emergence for neural components and around M1 emergence for facial components. (2) Associations between growth and age tend to be strong in those with full deciduous dentition, and weak in those who present M1 in full emergence. (3) Individuals who present M1 in full emergence are larger than those with full deciduous dentition. (4) Growth of components linked to the central nervous system is not linear until M1 emergence. Individuals who present M1 in full emergence are only larger than individuals with full deciduous dentition by 4-5% of adult size. (5) The alveolar component does not show increments between full deciduous dentition and M1 emergence. (6) When volumetric indices were standardized by age, the growth trajectories of individuals with full deciduous dentition and of those with M1 were not decoupled. In general terms, M1 emergence does not show a strong association with growth of the components that may explain differences in life histories. However, the main changes in neural and alveolar components occur in the first 3 years of life, which may be developmentally connected with M1 crown formation.     

A cross-sectional study of human craniofacial growth

It is generally accepted that different cranial regions do not follow the same growth pattern. In this study, size changes of the functional cranial components (FCCs) in 228 human skulls of age at death between 0 and 20 years were evaluated. The skull is considered as divided into anteroneural, midneural, posteroneural, otic, optic, respiratory, masticatory and alveolar FCCs. Age-related changes of FCCs were assessed by fitting curves with the smoothing spline method, and quantifying the proportional increments at different stages. All FCCs show a high growth rate in the first 3-5 years of life. Two groups of growth trajectories can be distinguished. The anteroneural, midneural, posteroneural and optic FCCs are more advanced at all stages; they show a high growth rate before 3-5-years-old and a low rate later. This difference is less pronounced in the group comprising the respiratory, masticatory and otic FCCs. The alveolar FCC shows an independent pattern. The similarities among FCCs of the two groups are best explained by their common embryological origin. In contrast, the participation in a common function cannot be associated with the co-ordinated variation, given that the masticatory and alveolar FCCs show independent trajectories.     

Mirror neurons responding to observation of actions made with tools in monkey ventral premotor cortex

In the present study, we describe a new type of visuomotor neurons, named tool-responding mirror neurons, which are found in the lateral sector of monkey ventral premotor area F5. Tool-responding mirror neurons discharge when the monkey observes actions performed by an experimenter with a tool (a stick or a pair of pliers). This response is stronger than that obtained when the monkey observes a similar action made with a biological effector (the hand or the mouth). These neurons respond also when the monkey executes actions with both the hand and the mouth. The visual and the motor responses of each neuron are congruent in that they share the same general goal, that is, taking possession of an object and modifying its state. It is hypothesized that after a relatively long visual exposure to tool actions, a visual association between the hand and the tool is created, so that the tool becomes as a kind of prolongation of the hand. We propose that tool-responding mirror neurons enable the observing monkey to extend action-understanding capacity to actions that do not strictly correspond to its motor representations. Our findings support the notion that the motor cortex plays a crucial role in understanding action goals.     

Changes in lymphocyte subsets in depressed HIV-infected patients without antiretroviral therapy

The authors studied the effects of major depression on lymphocyte subsets by comparing depressed and matched control subjects in a population of HIV-seropositive outpatients not treated with antiretroviral therapy. Twelve patients with major depression, as determined by the Structured Clinical Interview for DSM-III-R, were assessed in comparison with 15 matched nondepressed control subjects. Flow cytometric analysis of peripheral blood lymphocyte subsets together with immunological parameters were performed. In HIV-infected patients, major depression was significantly (P=0.001) associated with a reduction in natural killer cell absolute count and percentage. This report suggests that depression may alter the natural killer cell population that provides a cytotoxic defense against HIV infection.     

Multimodal architectonic subdivision of the rostral part (area F5) of the macaque ventral premotor cortex

We used a cyto‐, myelo‐, and chemoarchitectonic (distribution of SMI‐32 and calbindin immunoreactivity) approach to assess whether the rostral histochemical area F5 of the ventral premotor cortex (PMv) comprises architectonically distinct areas, possibly corresponding to functionally different fields. Three areas were identified, occupying different parts of F5. One area, designated as “convexity” F5 (F5c), extends on the postarcuate convexity cortex adjacent to the inferior arcuate sulcus and is characterized, cytoarchitectonically, by a poorly laminated appearance, resulting from an overall cell population rather homogeneous in size and density. The other two areas, designated as “posterior” and “anterior” F5 (F5p and F5a, respectively), lie within the postarcuate bank at different anteroposterior levels. Major cytoarchitectonic features of F5p are a layer III relatively homogeneous in cell size and density, a cell‐dense layer Va, and the presence of relatively large pyramids in layer Vb. Major cytoarchitectonic features of F5a are the presence of relatively large pyramids in lowest layer III and a prominent, homogenous layer V. Furthermore, our results showed that F5c and F5p border caudally with a caudal PMv area corresponding to histochemical area F4, providing additional evidence for a general subdivision of the macaque PMv into a caudal and a rostral part, corresponding to F4 and to the F5 complex, respectively. The present data, together with other functional and connectional data, suggest that the three rostral PMv areas F5p, F5a, and F5c correspond to distinct cortical entities, possibly involved in different aspects of motor control and cognitive motor functions. J. Comp. Neurol. 512:183–217, 2009. © 2008 Wiley‐Liss, Inc.