A 50-kDa membrane protein mediates sialic acid-independent binding and infection of conjunctival cells by adenovirus type 37

The ocular tropism of adenovirus type 37 (Ad37) does not correlate with the wide distribution of the 46-kDa coxsackievirus and adenovirus receptor (CAR), the major receptor for most adenovirus serotypes. We previously found that Ad37 infects and binds well to conjunctival cells (Chang C), but poorly to lung epithelial (A549) cells that express CAR and hypothesized that this serotype uses a distinct receptor that is selectively expressed on conjunctival cells. To test this, we produced particles of a fiber-deleted Ad5 vector containing the Ad37 fiber protein. The "pseudotyped" vector infected Chang C cells better than A549 cells using a CAR-independent pathway. Ad37 binding was calcium-dependent and was abolished by protease digestion of cell surface proteins. Using a virus overlay protein blot assay (VOPBA), we detected calcium-dependent Ad37 binding to 50- and 60-kDa membrane proteins on permissive Chang C cells. In contrast, calcium-dependent binding was detected with only the 60-kDa protein on nonpermissive A549 cells. Ad19p, a closely related serotype that failed to bind to conjunctival cells, recognized the 60-kDa, but not the 50-kDa, protein. Ad37 has been reported to use sialic acid instead of CAR as a cell receptor on A549 cells. Pretreatment of Chang C cells with neuraminidase abolished Ad37 binding to only the 60-kDa protein, suggesting that sialic acid mediates Ad37 binding to the 60-kDa protein. The pseudotyped Ad37 vector was also able to infect neuraminidase-treated Chang C cells. Thus, subgroup D adenoviral binding to the 50-kDa protein is calcium-dependent and cell type- and serotype-specific, whereas binding to the 60-kDa protein is not necessary for infection of conjunctival cells. Together, these data suggest that the 50-kDa protein is the major receptor for Ad37 on conjunctival cells.     

Mouse homologues of the human AZF candidate gene RBM are expressed in spermatogonia and spermatids, and map to a Y chromosome deletion interval associated with a high incidence of sperm abnormalities

An RNA-binding motif (RBM) gene family has been identified on the human Y chromosome that maps to the same deletion interval as the 'azoospermia factor' (AZF). We have identified the homologous gene family (Rbm) on the mouse Y with a view to investigating the proposal that this gene family plays a role in spermatogenesis. At least 25 and probably >50 copies of Rbm are present on the mouse Y chromosome short arm located between Sry and the centromere. As in the human, a role in spermatogenesis is indicated by a germ cell-specific pattern of expression in the testis, but there are distinct differences in the pattern of expression between the two species. Mice carrying the deletion Yd1, that maps to the proximal Y short arm, are female due to a position effect resulting in non-expression of Sry ; sex-reversing such mice with an Sry transgene produces males with a high incidence of abnormal sperm, making this the third deletion interval on the mouse Y that affects some aspect of spermatogenesis. Most of the copies of Rbm map to this deletion interval, and the Yd1males have markedly reduced Rbm expression, suggesting that RBM deficiency may be responsible for, or contribute to, the abnormal sperm development. In man, deletion of the functional copies of RBM is associated with meiotic arrest rather than sperm anomalies; however, the different effects of deletion are consistent with the differences in expression between the two species.      

Osteogenic potential of culture-expanded rat marrow cells as assayed in vivo with porous calcium phosphate ceramic

It has been established that, when whole marrow is introduced into porous calcium phosphate ceramic, bone forms on the walls of the pores. To extend earlier studies, bone marrow cells derived from the femora of inbred rats were introduced into tissue culture and the adherent cells cultivated, mitotically expanded, passaged, harvested, placed in small cubes of porous calcium phosphate ceramics and grafted into subcutaneous sites of syngeneic rats. Marrow-derived, cultured mesenchymal cells introduced into ceramics showed strong osteogenic potential, with bone forming in the pore regions of ceramics as early as 2 wk after implantation. Osteogenesis could be observed after the eighteenth passage. With increasing passage number, the initiation of osteogenesis and the apparent rate of bone formation declined and the course of osteogenesis was delayed. In the future, it may be possible to culture marrow cells as a source for reparative cells for implantation back into autologous in vivo sites.     

Osteogenesis imperfecta, rehabilitation medicine, fundamental research and mesenchymal stem cells

A speculative suggestion for a curative approach to osteogenesis imperfecta is based on the experimental observation that a pluripotent stem cell for mesenchymatous tissues can be isolated from marrow or periosteum. This cell, referred to as a Mesenchymal Stem Cell (MSC) could provide a vehicle for gene therapy based on that fact that many mesenchymal tissues have reasonably high cellular turnover rates. If autologous MSCs with the "proper" gene construct can be transplanted into affected patients, it may be that the progeny of the gene-corrected MSC can replace the defective mature phenotypes and bring about curative events associated with normal cell turnover.     

The ketogenic diet for intractable epilepsy in adults: preliminary results

PURPOSE: Little is known concerning the efficacy and adverse effects of the ketogenic diet in adults with refractory epilepsy. This review reports preliminary results in 11 adults prospectively treated with the diet who had previously failed to gain seizure control with two or more medications and/or surgery. METHODS: Eleven patients nine women, two men), median age, 32.2 years (range, 19-45 years) were treated with the ketogenic diet with a 4:1 ratio with fluid restriction. Six patients had symptomatic partial epilepsy, and five had symptomatic generalized epilepsy. The diet was administered in addition to antiepileptic medication by a multidisciplinary team geared exclusively to adult patients. Medications were not changed while on the diet. Seizure frequency at 8-month follow-up was compared with frequency during a baseline period. RESULTS: At 8 months of follow-up, three patients had a 90% seizure decrease, three patients had a 50-89% decrease in seizure frequency, one patient had <50% seizure decrease, and four patients discontinued the diet. Of the four patients who discontinued the diet, two had no appreciable change in their seizures despite high ketone levels. Two patients were unable to maintain persistent ketosis at home, despite having done so in the hospital. All seizure types responded to the diet. Common adverse effects included constipation and menstrual irregularities in women. Most patients reported a subjective improvement in concentration. Serum cholesterol and triglycerides increased while on the diet as well as cholesterol high-density lipoprotein (HDL) ratios. CONCLUSIONS: The ketogenic diet shows promise in both adult generalized and partial epilepsy. Persistent ketosis was possible in adults, and the diet was tolerable for most patients. Further study assessing the efficacy of the ketogenic diet, and the cognitive and long-term effects is ongoing.