Gene expression in mouse spermatogenesis during ontogenesis

In this study, we evaluated the expression of genes probably involved in spermatogenesis in the mouse. We examined cytosolic chaperonin theta subunit (CCTtheta), Ngg1 interacting factor 3 like 1 binding protein 1 (NIF3L1 BP1) and apolipoprotein H (ApoH) expression during mouse onto-geny using RT-PCR. Testicular tissue was obtained from mice 3, 6, 8, 10, 12, 14, 18, 20 and 40 (adult) days after birth. For each mouse, one testis was used for histological examination, whereas RNA was extracted from the controlateral testis for expression analysis. RT-PCR analysis showed that CCTtheta gene expression was low until day 10, but increased drastically afterwards. At this age, spermatocytes started to be present in the mouse testis. Therefore, CCT protein could be involved in chromatin packaging and remodeling during spermiogenesis, as also suggested by other studies. NIF3L1 BP1 expression increased steadily during ontogenesis reaching maximum levels in the adult mouse when all germ cell stages are present. This finding suggests that NIF3L1 BP1 is a gene not expressed by a specific germ cell type. ApoH expression was very low or absent during prepuberal stages, whereas it was detectable in the adult testis when spermatogenesis was completed. This suggests that ApoH may be involved in clearing apoptotic bodies during spermatogenesis since apoptotic events increase during spermatogenesis. This study contributes to understanding the role played by genes important for spermatogenesis.     

Ultrastructural study of the temporomandibular joint after unilateral meniscectomy in Wistar rats

Meniscectomy of the temporomandibular joint (TMJ) was frequently performed until a few years ago but now is seldom employed. This procedure induces important articular modifications but the complete extent of ultrastructural changes is still unknown. Twenty-one Wistar rats were submitted to unilateral meniscectomy. Animals were randomly divided into three groups and followed for 15, 35 or 60 days. After killing both meniscectomized and contralateral TMJ specimens were sectioned sagittally and prepared for light and scanning electron microscopy studies. Normal TMJs are characterized by glenoid fossa and condylar process with distinct conjunctive layers in which regularly arranged type 1 collagen fibres predominate. Meniscectomized animals initially exhibit a different tissue covering the eroded articular surface of the condyle with the prevalence of type 3 collagen fibres but type 1 fibres predominate in the late postoperative period. Subchondral cysts are clearly visible. A complex remodelling process of the TMJ after meniscectomy is evident with important ultrastructural modifications that may correlate to unsatisfactory clinical results. The dynamic nature of this process is also observed when specimens from different postoperative periods are compared. Surgeons should always bear in mind these alterations when indicating this procedure.     

Hyperplasie des Processus coronoideus: Diagnose und Therapie

Study goal

As it is an unusual and infrequent clinical entity, hyperplasia of the coronoid process is often overlooked or diagnosed too late. The aim of this study was to characterize the morphology, etiology, and clinical picture of coronoid hyperplasia as well as to discuss its diagnosis and treatment.

Materials and methods

All cases of histologically confirmed hyperplasia of the coronoid process treated in our center between 1995 and 2004 were analyzed. Patient data were evaluated with respect to age, gender, clinical symptoms, diagnostic work-up, and treatment. The extracted data were compared to those found in the literature.

Results

The study included 14 new cases and 101 cases already published: 96 with bilateral and 19 with unilateral hyperplasia. At the time of diagnosis, the subjects' mean age was 23.7?years. The patients in Bonn were all treated by coronoidectomy and appropriate physiotherapy. An improvement in mouth opening could be achieved in 86% of our patients.

Conclusions

In comparison to the somewhat disappointing results of previously published studies with regard to mouth opening and mandibular mobility, our treatment concept seems to offer the possibility for improvement. Our study emphasizes the significance of three-dimensional CT techniques for diagnosis and surgical planning, the superiority of coronoidectomy over coronoidotomy, and the importance of dynamic physiotherapy to prevent postoperative scar formation.     

Circulating biomarkers of cognitive decline and dementia

Plasma and serum biochemical markers proposed for cognitive decline of degenerative (Alzheimer's disease, AD) or vascular origin and predementia syndromes (mild cognitive impairment and other related entities) are based on pathophysiologic processes such as lipoprotein metabolism (total cholesterol, apolipoprotein E, 24S-hydroxy-cholesterol), and vascular disease (homocysteine, lipoprotein(a)); SP formation (amyloid beta(Abeta)-protein, Abeta autoantibodies, platelet APP isoforms), oxidative stress (isoprostanes, vitamin E), and inflammation (cytokines). This review will focus on the current knowledge on circulating serum and plasma biomarkers of cognitive decline and dementia that are linked to cholesterol homeostasis and lipoprotein abnormalities, senile plaque formation and amyloid precursor protein (APP) metabolism, oxidative stress, and inflammatory reactions. Special emphasis will, however, be placed on biomarkers related to lipoprotein metabolism and vascular disease. Analytically, most plasma and serum proteins or metabolites lack reproducibility, sensitivity, or specificity for the diagnosis, risk and progression assessment, or therapeutic monitoring of AD and other dementing disorders. Measures linked to lipoprotein metabolism and vascular disease, APP metabolism, oxidative stress, or inflammation appear altered in AD relative to controls, but lack sufficient discriminatory power. Measures combining several biomarkers or incorporating a range of proteins in plasma and small molecule metabolites are promising approaches for the development of plasma or serum-based diagnostic tests for AD and other dementing disorders, as well as for predementia syndromes.     

ATRX syndrome in a girl with a heterozygous mutation in the ATRX Zn finger domain and a totally skewed X-inactivation pattern

Mutations in the X-encoded gene ATRX are known to give rise to syndromic mental retardation in male patients whereas female carriers show preferential inactivation of the mutated X chromosome and appear healthy. Here, we describe a 4-year-old girl with typical features of ATRX syndrome, carrying the recurrent R246C mutation of ATRX. We show that her pattern of X-inactivation is totally skewed and that her active X chromosome which harbors the ATRX mutation, was maternally inherited. To our knowledge, this is the first report of ATRX syndrome in a female patient. Since she was born after in vitro fertilization (IVF), we propose a possible link between assisted reproduction technologies (ART) and the unexpected X chromosome methylation pattern that we observed.     

Interpreting procedures from descriptive guidelines

Errors in clinical practice guidelines may translate into errors in real-world clinical practice. The best way to eliminate these errors is to understand how they are generated, thus enabling the future development of methods to catch errors made in creating the guideline before publication. We examined the process by which a medical expert from the American College of Physicians (ACP) created clinical algorithms from narrative guidelines, as a case study. We studied this process by looking at intermediate versions produced during the algorithm creation. We identified and analyzed errors that were generated at each stage, categorized them using Knuth's classification scheme, and studied patterns of errors that were made over the set of algorithm versions that were created. We then assessed possible explanations for the sources of these errors and provided recommendations for reducing the number of errors, based on cognitive theory and on experience drawn from software engineering methodologies.