Impaired carbohydrate metabolism of polymorphonuclear leukocytes in glycogen storage disease Ib.

This study measures hexose monophosphate (HMP) shunt activity, glycolytic rate, and glucose transport in PMN and lymphocytes of patients with glycogen storage disease (GSD) type Ib as compared with controls and with GSD Ia patients. HMP shunt activity and glycolysis were significantly lower in intact PMN cells of GSD Ib patients as compared with GSD Ia patients and with controls. These activities were above normal levels in disrupted GSD Ib PMN. HMP shunt activity and glycolytic rates in lymphocytes were similar in all three groups studied. The rate of 2-deoxyglucose transport into GSD Ib PMN was 30% of that into cells of normal controls. In GSD Ib lymphocytes or in GSD Ia PMN and lymphocytes transport was normal. The striking limitation of glucose transport across the cell membrane of the PMN of GSD Ib patients may account for the impairment of leukocyte function that is characteristic of GSD Ib, but not found in GSD Ia patients.     

Alpha-enolase resides on the cell surface of Mycoplasma fermentans and binds plasminogen

Plasminogen (Plg) binding to the cell surface of Mycoplasma fermentans results in a marked increase in the maximal adherence of the organism to HeLa cells, enhanced Plg activation by the urokinase-type Plg activator, and the induction of the internalization of M. fermentans by eukaryotic host cells (A. Yavlovich, A. Katzenell, M. Tarshis, A. A. Higazi, and S. Rottem, Infect. Immun. 72:5004-5011, 2004). In this study, the M. fermentans Plg binding protein was isolated by affinity chromatography of Triton X-100-solubilized M. fermentans membranes by utilizing a column of a Plg-biotin complex attached to avidin that was eluted with -aminocaproic acid. The eluted ~50-kDa protein was identified by mass spectrometric techniques as α-enolase. The possibility that α-enolase, a key cytoplasmatic glycolytic enzyme, resides also on the cell surface of M. fermentans was supported by an immunoblot analysis using polyclonal anti-α-enolase antiserum, which showed that α-enolase was present in a purified M. fermentans membrane preparation, as well as by immunochemical criteria and by immunoelectron microscopy analysis. Our observation that Plg blocked the binding of anti-α-enolase antibodies to a 50-kDa polypeptide band resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of M. fermentans membrane or soluble preparations further supports our notion that mycoplasmal surface α-enolase is a major Plg binding protein of M. fermentans.     

Height in adolescence as a risk factor for glioma subtypes: a nationwide retrospective cohort study of 2.2 million subjects

BackgroundGliomas manifest in a variety of histological phenotypes with varying aggressiveness. The etiology of glioma remains largely unknown. Taller stature in adulthood has been linked with glioma risk. The aim of this study was to discern whether this association can be detected in adolescence.MethodsThe cohort included 2 223 168 adolescents between the ages of 16 and 19 years. Anthropometric measurements were collected at baseline. Incident cases of glioma were extracted from the Israel National Cancer Registry over a follow-up period spanning 47 635 745 person-years. Cox proportional hazard models were used to estimate the hazard ratio (HR) for glioma and glioma subtypes according to height, body mass index (BMI), and sex.ResultsA total of 1195 patients were diagnosed with glioma during the study period. Mean (SD) age at diagnosis was 38.1 (11.7) years. Taller adolescent height (per 10-cm increase) was positively associated with the risk for glioma of any type (HR: 1.15; P = .002). The association was retained in subgroup analyses for low-grade glioma (HR: 1.17; P = .031), high-grade glioma (HR: 1.15; P = .025), oligodendroglioma (HR: 1.31; P = .015), astrocytoma (HR: 1.12; P = .049), and a category of presumed IDH-mutated glioma (HR: 1.17; P = .013). There was a trend toward a positive association between height and glioblastoma, however this had borderline statistical significance (HR: 1.15; P = .07). After stratification of the cohort by sex, height remained a risk factor for men but not for women.ConclusionsThe previously established association between taller stature in adulthood and glioma risk can be traced back to adolescence. The magnitude of association differs by glioma subtype.     

Review on squeaking hips

Squeaking is a well-recognized complication for hard-on-hard bearings. The nature of squeaking is not yet completely understood however it is considered a multifactorial phenomenon. Patient, implant, and surgical factors play a role in squeaking. It is believed that mechanisms damaging the fluid film lubrication in which these bearings function optimally have a critical role. Such mechanisms include edge loading, stripe wear, impingement, third body particles and ceramic fracture. The resonance of metallic parts can produce noise in the human audible range hence the implant metallurgic composition and design may play a role. Implant positioning can facilitate impingement and edge loading enhancing the occurrence of squeaking. The recent introduction of large heads (> 36 mm) 4^th generation ceramic-on-ceramic bearing may accentuate the conditions facilitating noise formation; however the current literature is insufficient. Clinically, squeaking may manifest in extreme hip positions or during normal gait cycle however it is rarely associated with pain. Evaluations of patients with squeaking include clinical and radiographic assessments. Computer tomography is recommended as it can better reveal ceramic breakage and implant malposition. The treatments for most squeaking patients include reassurance and activity modification. However for some, noise can be a problem, requiring further surgical intervention. In the occurrence of ceramic fracture, implant failure, extreme components malposition, instability and impingement, surgery should be advised. This review will aim to discuss the current literature regarding squeaking.     

Butyrylcholinesterase attenuates amyloid fibril formation in vitro

In Alzheimer's disease, both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) colocalize with brain fibrils of amyloid-beta (Abeta) peptides, and synaptic AChE-S facilitates fibril formation by association with insoluble Abeta fibrils. Here, we report that human BChE and BSP41, a synthetic peptide derived from the BChE C terminus, inversely associate with the soluble Abeta conformers and delay the onset and decrease the rate of Abeta fibril formation in vitro, at a 1:100 BChE/Abeta molar ratio and in a dose-dependent manner. The corresponding AChE synthetic peptide (ASP)40 peptide, derived from the homologous C terminus of synaptic human (h)AChE-S, failed to significantly affect Abeta fibril formation, attributing the role of enhancing this process to an AChE domain other than the C terminus. Circular dichroism and molecular modeling confirmed that both ASP40 and BChE synthetic peptide (BSP)41 are amphipathic alpha-helices. However, ASP40 shows symmetric amphipathicity, whereas BSP41 presented an aromatic tryptophan residue in the polar side of the C terminus. That this aromatic residue is causally involved in the attenuating effect of BChE was further supported by mutagenesis experiments in which (W8R) BSP41 showed suppressed capacity to attenuate fibril formation. In Alzheimer's disease, BChE may have thus acquired an inverse role to that of AChE by adopting imperfect amphipathic characteristics of its C terminus.