Isolated neuropraxy of the musculocutaneous nerve

Authors describe a case of isolated posttraumatic neuropraxy of the musculocutaneous nerve. With the presentation of this very rare case attention is called, based on literary date, to the fact that the above injury can be mixed with the distal tendon rupture of the biceps.     

Malignant tumours after renal transplantation.

The incidence of malignant tumours in 570 patients with kidney transplants was examined. It was found to be 20-30 times higher than in the average (normal) population. In accordance with the literature, mainly skin cancers were observed, but at variance with these data, the number of lymphoreticular malignancies was small. On the basis of their study, the authors emphasize the oncogenetic effect of immunosuppression. By comparing the conventional (AZA+PRED) and Cyclosporine (CYA+PRED) treatments, they point out that this risk should be taken into consideration even in Cyclosporine therapy which has otherwise a much more favourable effect.     

Association between vertical development of the cervical spine and the face in subjects with varying vertical facial patterns.

The upper cervical spine and face were compared longitudinally from 6 to 15 years of age in 2 groups of children with low (n = 16) and high (n = 14) MP-SN angles. The purpose of the study was to assess morphological and incremental associations between the vertical development of the cervical spine and the face in subjects with varying vertical facial patterns. Morphological associations were not detected during the observation period. Long faces were found on children with short necks, and short, square faces on those with long necks. Vertical growth of the upper cervical spine and face were weakly correlated in the 6-to-12-year period but strongly correlated later during puberty. The vertical distance between gonion and the body of the second cervical vertebra was remarkable for its constancy during childhood and puberty, indicating that gonion and the second cervical vertebra body were anatomically interrelated. This anatomical relationship strongly suggests that a mutual relationship also exists between vertical growth of the upper cervical spine and the face, especially the lower face. In addition, the lower face had the ability for independent vertical growth that was not coordinated with vertical cervical growth. This was the case in the 6-to-12-year period, but not later.     

Lumbosacral glioblastoma and leptomeningeal gliomatosis complicating the course of a cervicothoracic astrocytoma WHO grade II

CASE REPORT: The reported female patient underwent sub-total resection of an intra-medullary cervicothoracic astrocytoma classified as WHO grade II in 1984 at the age of 18 months and received local irradiation. In 1989, a local recurrence was diagnosed and a partial resection was performed. Sixteen years later, a small recurrent cervicothoracic tumour was found and spinal seeding to the equine nerve roots and the left cerebellar cortex was apparent on MRI. The patient was implanted with a ventriculoperitoneal shunt for a pseudo-tumour cerebri producing papilloedema, which eventually lead to amaurosis. After an extended biopsy, the invasive lumbosacral tumour was classified as glioblastoma multiforme. Two months later, the patient died after rapid progression of the caudal cranial nerve dysfunction. DISCUSSION AND CONCLUSION: Anaplastic progression and dissemination of spinal astrocytomas even two decades after initial diagnosis and treatment are rare. Therapies and diagnostic follow-up strategies are discussed.     

Suppression of B cell differentiation by ligation of membrane-bound IgM

Using B cells from the transgenic mouse line B6-Sp6 and control littermates, stimulated by lipopolysaccharide (LPS) under novel culture conditions that provide for the response of all B cells, we show here that specific ligation of the surface IgM molecules always results in inhibition of terminal differentiation and immunoglobulin secretion by activated cells, regardless of the ligand. Thus, monoclonal antibodies to (a) the CH region of Ig (anti-μ. and anti-allotype), (b) the Cx region, (c) the V region (anti-idiotype) of surface IgM, as well as (d) multivalent antigen (2,4,6-trinitrophenyl-bovine serum albumin), all show similar effects and dose-response curves. IgD-negative transgenic B cells are equally sensitive to IgM ligation-dependent inhibition, as control (IgD-positive) B cells. The allotype specificity of this inhibition, assessed by using anti-u, allotype reagents to inhibit and assay the responses, suggests that B cells expressing transgenic or endogenous IgM in transgenic B6-Sp6 mice are largely independent populations. These observations establish that anti-IgM antibodies in conjunction with appropriate LPS stimulation, provide a universal model system for functional characterization of B cell responses.     

Nitroblue-tetrazolium test for the functional evaluation of phagocytic cells: A critical analysis of the methodology

The reduction of NBT to formazan has been suggested as an indicator of the reduction potential of biological systems. An increase in the amount of reduced formazan reflects the activation of the hexose monophosphate shunt of phagocytes cultivated in vitro, as a result of cellular stimulation by chemical or biological factors, or during phagocytosis. This phenomenon has been widely used for the determination of activated phagocytes by different methods. However, the technical limitations of these methods have not been evaluated carefully. In the investigations presented here threesolvents for formazan, pyridine, dioxane and dimethylformamide, have been tested for their suitability as extraction agents. For each solvent the optimal wavelength for photometric evaluation has been determined and dose relation curves between dissolved formazan and OD have been established. Several factors (time, temperature, pH, contamination with water or acid) affecting the dissolving properties and stability of formazan in different solvents have been investigated. With the solvents tested, dioxane proved to be the most suitable agent for extracting NBF. Thus, a methodology for the quantitative evaluation of NBT has been established. This method can be used for the identification of activators as well as of inhibitors of the phagocyte system.     

Retinoids and spermatogenesis: lessons from mutant mice lacking the plasma retinol binding protein.

Using Rbp4-null mice as models, we have established for the first time the kinetics of the spermatogenetic alterations during vitamin A deficiency (VAD). Our data demonstrate that the VAD-induced testicular degeneration arises through the normal maturation of germ cells in a context of spermatogonia differentiation arrest. They indicate that retinoic acid (RA) appears dispensable for the transition of premeiotic to meiotic spermatocytes, meiosis, and spermiogenesis. They confirm that RA plays critical roles in controlling spermatogonia differentiation, spermatid adhesion to Sertoli cells, and spermiation, and suggest that the VAD-induced arrest of spermatogonia differentiation results from simultaneous blocks in RA-dependent events mediated by RA receptor gamma (RARgamma) in spermatogonia and by RARalpha in Sertoli cells. They also provide evidence that expression of major RA-metabolizing enzymes is increased in mouse Sertoli cells upon VAD and that vitamin A-deficient A spermatogonia differ from their RA-sufficient counterparts by the expression of the Stra8 gene.