FcR gamma-chain is essential for both surface expression and function of human Fc gamma RI (CD64) in vivo

Most Ig receptors exist as hetero-oligomeric complexes with separate ligand binding (alpha) and signal transducing (beta, gamma, or zeta) subunits. For Fc gamma RIIIa and Fc epsilon RI, association with the FcR gamma-chain is essential for surface expression. However, the human high affinity IgG receptor, hFc gamma RI, was found to be surface- expressed by itself in transient transfection models. We have now analyzed the integrity of hFc gamma RI expression in more detail in stable transfectants. In vitro we noted that, in the absence of FcR gamma-chain, surface expression of hFc gamma RI rapidly declined to background levels, in both IIA1.6 B cells and NIH3T3 fibroblasts. The effect of FcR gamma-chain on hFc gamma RI surface expression in vivo was evaluated by using two newly generated transgenic mouse lines, selectively expressing hFc gamma RI on myeloid cells. These transgenic mice were crossed with FcR gamma-chain-deficient mice. Analysis of blood monocytes and peritoneal macrophages showed that surface expression of hFc gamma RI was reduced by approximately 80%. The remaining approximately 20% of receptors were still capable of binding IgG-opsonized RBC, suggesting FcR gamma-chain not to be critical for hFc gamma RI ligand-binding capacity. Importantly, however, hFc gamma RI signaling capacity was lost in FcR gamma-chain-deficient cells. No phagocytosis could be observed using either ligand sensitized (EA- IgG2a) or CD64-targeted erythrocytes (using a bispecific antibody) in both hFc gamma RI transgenic lines. This documents the FcR gamma-chain to be indispensable for both surface membrane expression and function of human Fc gamma RI in vivo.     

Mycobacterial Infections After Renal Transplantation

Mycobacterial infections occurred in 11 of 633 (1.7 per cent)recipients of successful renal transplants. There were no casesof tuberculosis in patients receiving chemoprophylaxis, butamongst those who did not receive prophylaxis disease occurredin six of the 27 (22 per cent) high-risk patients. The majorcause of morbidity during treatment was renal allograft rejection,largely due to reduction in immunosuppressive drug therapy.     

Conservative management of rectal perforation after nerve sparing endoscopic extraperitoneal radical prostatectomy (NS EERPE) in a patient with a past history of polypectomy

Introduction

Rectal polypectomy causes thinning (or even perforation) of the rectal wall in addition to thermic injury at the polypectomy site.

Case report

We present a rare case of spontaneous rectal perforation after uncomplicated nerve sparing endoscopic extraperitoneal radical prostatectomy in a patient with a previous history of rectal polypectomy at the perforation site. The patient could be treated conservatively. There was complete healing of the fistula without any effect on functional results. This Conservative therapy for such rectal perforations is indicated if the patient''s general condition remains stable without any signs of infection.

Conclusions

Polypectomy is an important risk factor for rectal perforation during nsEERPE. Adequate time interval should be given to allow healing and avoid adding further thermal wall damage which may obscure healing leading to complications like fistula. Conservative therapy for small missed rectal perforations constitutes an attractive, feasible and non invasive treatment entity. Following this principle we have not faced this complication in following similar cases.     

Van der Woude syndrome: dentofacial features and implications for clinical practice

Background:  Van der Woude syndrome (VWS) is the most common clefting syndrome in humans. It is characterized by the association of congenital lower lip fistulae with cleft lip and/or cleft palate. VWS individuals have a high prevalence of hypodontia. Although caused by a single gene mutation, VWS has variable phenotypic expression. This study aimed to describe the range of clinical presentations in 22 individuals with VWS to facilitate its diagnosis.
Methods:  A retrospective study of 22 patients with a diagnosis of VWS was undertaken at the Australian Craniofacial Unit (ACFU) in Adelaide. Three extended families with affected members were included in the study cohort.
Results:  The overall prevalence of lip pits in this study cohort was 86%. Cleft phenotypes included bilateral cleft lip and palate (32%); unilateral cleft lip and palate (32%); submucous cleft palate (23%); and isolated cleft hard and soft palate (9%). Missing permanent teeth were reported in 86% of affected individuals.
Conclusions:  Submucous cleft palate in VWS may go undiagnosed if the lower lip pits are not detected. Associated hypodontia and resultant malocclusions will also require management by a dental team.     

Development of new physical activity and sedentary behavior change self-efficacy questionnaires using item response modeling

Background  

Theoretically, increased levels of physical activity self-efficacy (PASE) should lead to increased physical activity, but few studies have reported this effect among youth. This failure may be at least partially attributable to measurement limitations. In this study, Item Response Modeling (IRM) was used to develop new physical activity and sedentary behavior change self-efficacy scales. The validity of the new scales was compared with accelerometer assessments of physical activity and sedentary behavior.     

Leg ulceration and ethnicity: a study in west London

Little is known of the influence race has on the development of leg ulceration, with most studies being performed in almost exclusively white populations. As part of a wider audit of leg ulcer services, health care professionals were contacted to give details of age, sex and ethnic background of all patients who attended for treatment of leg ulceration over a one year period in an area of west London. West London Health Care Trust provides services to a population of 275000 of whom 53000 have an ethnic background from the Indian subcontinent (South Asian).In all, 280 patients were identified, of whom 264 (94%) had details of age and sex. This gave a crude ascertainment rate of 1.02 per 1000 population. Of the 264 patients, five were classified as South Asians, with one patient classified as Afro-caribbean. The Mantel Haenzsel test demonstrated a significantly higher proportion of whites suffering from leg ulceration than South Asians, giving an odds ratio of 4.43, with 95% confidence intervals between 1.94 and 10.13 (P=0.0004). The expected frequency of South Asian patients should be 23, based on rates from the white population, of which 13 would be women and 10 men. Only five South Asian men were identified, and no Asian women with leg ulceration.Reasons for this low ascertainment are two-fold. Either there is a real difference between the white and South Asian populations, or South Asian patients are not presenting for treatment. Further work must be performed to determine whether this is an effect of low prevalence, or unmet need in the community.