Patellofemoral joint arthroplasty: patient selection,surgical technique and outcomes

Isolated patellofemoral arthritis is an increasingly recognized entity, and is usually associated with previous patellofemoral dysplasia or instability. Patellofemoral arthroplasty (PFA) has evolved significantly in recent years, both in terms of implant design and importantly in the understanding of appropriate patient selection. This review outlines the indications and investigations for PFA, provides a brief history of the development of contemporary implants, and presents the clinical outcomes for the prostheses most commonly used in the UK. In addition, it provides a detailed surgical technique for implantation of an onlay implant, with tips on how to optimize patellofemoral biomechanics and thus achieve a consistently good outcome.     

Effects of intracavernosal trazodone hydrochloride: animal and human studies

Trazodone hydrochloride is an oral antidepressant agent which has been associated with the improvement of erections in impotent men and the development of prolonged erections or priapism in potent men. An in vivo study in animal and human subjects was performed to gain experience with the effect of intracavernosal trazodone. In the anesthetized New Zealand White rabbit, intracavernosal trazodone or its major metabolite m-chlorophenylpiperazine (m-CPP) produced full penile erection in 76% and 84% of animals studied respectively with doses ranging from one to 15 mg. On the other hand, intracavernosal administration of five mg. papaverine resulted in a prolonged erection in 90% of animals studied. In 13 selected volunteer patients, intracavernosal trazodone caused tumescence but not full penile erection with corporal body pressures of 28.2 +/- 5.8 mm. Hg. Intracavernosal papaverine or papaverine and phentolamine in these subjects resulted in significantly higher corporal body pressures of 58 +/- 18 mm. Hg (p less than .05). Intracavernosal administration of alpha adrenoceptor agonists but not normal saline resulted in complete detumescence of trazodone- or m-CPP-induced prolonged erection in the animal studies. Intracavernosal trazodone results in erectile activity that appears in part based on its local alpha blocking activity but like other intracavernosal alpha-blocking agents is not as effective in initiating penile erections as are intracavernosal agents that directly induce smooth muscle relaxation.     

Cross reactivity between IA-2 and phogrin/IA-2β in binding of autoantibodies in IDDM

Summary Patients with insulin-dependent diabetes mellitus (IDDM) possess antibodies to the cytoplasmic domains of two closely related tyrosine phosphatase-like proteins, IA-2 and phogrin, previously detected as 40 kDa and 37 kDa tryptic fragments, respectively. A higher proportion of IDDM patients possess antibodies to IA-2 than to phogrin, and autoimmunity to phogrin might arise through cross-reactivity with the highly homologous IA-2. In this study, we have investigated the major regions of IA-2 recognized by antibodies in IDDM patients and examined the ability of phogrin to block antibody binding to these regions as a measure of cross-reactivity. Analysis of antibody binding to in vitro transcribed and translated polypeptides representing different regions of the cytoplasmic domain of IA-2 identified five different patterns of reactivity with antibodies in IDDM. Protein footprinting analysis, whereby polypeptide fragments generated on protease treatment of immune complexes are studied, indicated considerable heterogeneity in antibody recognition of IA-2, even between sera with similar reactivity to deletion mutants. Blocking studies with recombinant phogrin indicated that IA-2 antibodies recognize epitopes that are both unique to IA-2 and shared with phogrin. The amino-terminal 150 amino acids of the cytoplasmic domain of IA-2 encompass epitopes that are not represented on phogrin, whereas shared epitopes are localized within the carboxy-terminal 220 amino acids. The results demonstrate considerable heterogeneity between IDDM patients in autoantibody recognition of IA-2 in IDDM, whereas antibody recognition of phogrin is restricted in most patients to epitopes also present on IA-2. [Diabetologia (1997) 40: 1327–1333] Received: 4 April 1997 and in revised form: 2 July 1997     

Absence of an association between HLA-DRB1*04 and rheumatoid arthritis in newly diagnosed cases from the community.

OBJECTIVES--To determine HLA-DR4 and DR1 allele frequencies in a series of patients with newly diagnosed early inflammatory arthritis. METHODS--HLA-DR1 and DR4 frequencies were determined by oligonucleotide typing of 208 patients classified as having either rheumatoid arthritis (RA) or undifferentiated inflammatory polyarthritis. RESULTS--The frequency of occurrence of DR4 in these patients with RA did not differ significantly from that in controls in the United Kingdom (42 v 37%). HLA-DR1 was increased in the group with inflammatory polyarthritis (25 v 18%). CONCLUSIONS--The frequency of DR4 is not increased in newly diagnosed community based patients with RA. This supports the hypothesis that DR4 is less important as a marker for susceptibility to RA than it is for disease persistence or severity.