Expression and subcellular localization of efflux transporter ABCG2/BCRP in important tissue barriers of lactating dairy cows, sheep and goats

Expression of efflux transporter ABCG2/BCRP in tissues barriers has shown to be associated with altered pharmaco- and toxicokinetics of xenobiotics. Until now, little is known about the functional expression of this transporter in dairy animals. We therefore systematically examined the expression and subcellular localization of ABCG2/BCRP in small intestine, colon, lung, liver, kidney and mammary gland in lactating cows, sheep and goats. Carrier expression was investigated by RT-PCR and Western blot analysis showing highest expression of ABCG2/BCRP in small intestine and mammary gland, high levels in liver and moderate amounts of protein in lung, colon and kidney. Regarding subcellular localization, BCRP was predominantly found at the apical plasma membrane of small intestine, colon, bronchial epithelium, bile ducts and overall in endothelial structures in all tested species. In the mammary gland, there was strong apical staining of the alveolar epithelial cells and most of the ducts in all dairy ruminants. We also detected significantly elevated protein expression in lactating mammary gland compared with nonlactating cows, sheep and goats. Our results contribute to the role of BCRP in cytoprotection and disposition in important tissue barriers and may have important implications for veterinary pharmacotherapy of dairy animals using drugs identified as BCRP substrates.

MYCN and ALKF1174L are sufficient to drive neuroblastoma development from neural crest progenitor cells

Neuroblastoma is an embryonal tumor with a heterogeneous clinical course. The tumor is presumed to be derived from the neural crest, but the cells of origin remain to be determined. To date, few recurrent genetic changes contributing to neuroblastoma formation, such as amplification of the MYCN oncogene and activating mutations of the ALK oncogene, have been identified. The possibility to model neuroblastoma in mice allows investigation of the cell of origin hypothesis in further detail. Here we present the evidence that murine neural crest progenitor cells can give rise to neuroblastoma upon transformation with MYCN or ALK(F1174L). For this purpose we used JoMa1, a multipotent neural crest progenitor cell line, which is kept in a viable and undifferentiated state by a tamoxifen-activated c-Myc transgene (c-MycER(T)). Expression of MYCN or ALK(F1174L), one of the oncogenic ALK variants identified in primary neuroblastomas, enabled these cells to grow independently of c-MycER(T) activity in vitro and caused formation of neuroblastoma-like tumors in vivo in contrast to parental JoMa1 cells and JoMa1 cells-expressing TrkA or GFP. Tumorigenicity was enhanced upon serial transplantation of tumor-derived cells, and tumor cells remained susceptible to the MYC-inhibitor, NBT-272, indicating that cell growth depended on functional MYCN. Our findings support neural crest progenitor cells as the precursor cells of neuroblastoma, and indicate that neuroblastomas arise as their malignant progeny.

Mutations in FRMD7, a newly identified member of the FERM family, cause X-linked idiopathic congenital nystagmus

Idiopathic congenital nystagmus is characterized by involuntary, periodic, predominantly horizontal oscillations of both eyes. We identified 22 mutations in FRMD7 in 26 families with X-linked idiopathic congenital nystagmus. Screening of 42 singleton cases of idiopathic congenital nystagmus (28 male, 14 females) yielded three mutations (7%). We found restricted expression of FRMD7 in human embryonic brain and developing neural retina, suggesting a specific role in the control of eye movement and gaze stability.

Dosis-Wirkungs-Beziehung bei Revisionsoperation des konsekutiven Strabismus divergens im Erwachsenenalter

BACKGROUND

The aim of this study was to establish a dose-effect relationship between the reduction of the angle of deviation and the millimeters of the reoperation performed in patients with consecutive exotropia.

PATIENTS AND METHODS

A total of 46 patients who had undergone reoperation for consecutive exotropia (group 1: advancement of the former recessed medial rectus muscle and group 2: additional rececession of the lateral rectus muscle) were reexamined.

RESULTS

The dose-effect relationship was 2 degrees /mm in group 1 and1.6 degrees /mm far distance and 1.8 degrees /mm near in group 2. Within the first 4 months after the reoperation we found an exodrift of up to 6 degrees , which remained stable; 98% of our patients reported that their quality of life had improved.

CONCLUSION

In cases of consecutive exotropia we consider the postoperative exdodrift in the planing of our reoperation. During the ensuing years patients can expect stability of the results achieved by the reoperation.

Trough levels of mycophenolic acid and its glucuronidated metabolite in renal transplant recipients

OBJECTIVE

The prophylactic use of the immunosuppressant prodrug, mycophenolate mofetil (MMF) to prevent graft rejection in renal transplant patients is continuing to increase. We measured trough levels of the active metabolite, mycophenolic acid (MPA) and its inactive glucuronide (MPAG) in renal recipients with the aim of characterizing individual variability and of ascertaining factors influencing trough levels, in particular the effect of differences in renal function and the effect of drugs given concurrently.

METHODS

Laboratory and clinical data obtained in 35 renal recipients treated with triple therapy (MMF, cyclosporin A (CsA), steroids) were included in this retrospective study. Trough levels of MPA and MPAG were obtained after transplantation and up to 16 months post transplantation where the mean observation period was 5.7 months. Plasma levels were measured using a validated HPLC assay.

RESULTS

A total of 212 plasma concentrations of MPA and 209 of MPAG were measured. There was considerable intra- and interindividual variability in MPA and MPAG trough levels especially in the early post-transplantation phase. At a fixed dose of 2 g/d MMF, the mean MPA level during the first 30 days averaged 1.46 +/- 1.31 microg/ml vs. 1.87 +/- 0.89 microg/ml after 30 days and later (p = 0.130) and the mean MPAG concentration averaged 188.1 = 142.8 [microg/ml vs. 98.09 +/- 52.4 microlg/ml (p 0.003). The MPAG levels were positively correlated with the serum creatinine concentrations (r = 0.815, p < 0.001), and in the case of MPA there was a correlation with the serum protein concentrations (r = 0.258, p = 0.001). Concomitant drug treatment using CsA, steroids and furosemide were without effect of the measured plasma concentrations, but in the case of xipamide (+) and diltiazem (-) an effect on MPA and MPAG levels and a co-effect depending on the serum creatinine could not be excluded. Neither CsA trough levels nor hemoglobin levels were related to MPA and MPAG trough levels.

CONCLUSIONS

The data of this study demonstrate that there is substantial individual variability in the trough levels of MPA and MPAG after renal transplantation which may be associated with the functional status of the graft and the serum protein level. Whether comedication with xipamide and diltiazem affects the plasma levels of MPA and MPAG remains to be clarified in further investigations.

[Medical aspects of the squint operation as day surgery - a contribution to quality control]

BACKGROUND

The strained situation in the financing of our health system makes it necessary that we reassess therapeutic procedures and their management. Since the squinting operation is mainly performed in the form of day surgery in the English-language area, we followed this example and treated 112 patients in this way. Afterwards we examined their acceptance in cooperation with the Department for Interdisciplinary Quality Management.

PATIENTS AND METHOD

112 patients in whom a squinting operation had been performed in the form of day surgery, received a comprehensive questionnaire with 24 questions, which had been compiled together with the Institute for Psychology, the Institut for Social Medicine and the University Clinic for anaesthesiology.

RESULTS

There was a very high acceptance and a positive feedback so that for 3 years now we reserve one day per week for squinting operations in the form of day surgical performance.

Oktreotidszintigraphie zur Diagnose der aktiven endokrinen Orbitopathie

PURPOSE

In this study the diagnostic accuracy of orbital octreotide uptake in patients with presumed active Grave's ophthalmopathy (GO) was evaluated.

PATIENTS AND METHODS

A prospective study of 23 patients suffering from GO was carried out. Single photon emission computed tomography (SPECT) images were obtained 4 h after iv injection of 3 mCi 111 indium octreotide. The results were correlated with the patients clinical state during a follow-up of 17.5+/-6 months.

RESULTS

Octreotide scintigraphy was positive in 15 and negative in 8 cases, 12 patients with positive octreotide scintigraphy underwent immunosuppressive treatment and showed a clinically positive response with regression of symptoms. In three cases the patients refused immunosuppressive treatment. Patients with negative pathologic orbital octreotide uptake did not undergo any treatment.

CONCLUSION

Octreotide scintigraphy is a useful tool to determine the activity state of Graves' ophthalmopathy. Since Graves' ophthalmopathy must be treated in the active phase, octreotide scintigraphy should be performed in subacute cases to facilitate the indications for immunosuppressive treatment.

[Diplopia after encircling procedure for retinal detachment]

PURPOSE

Our aim was to evaluate the frequency, duration and therapy of diplopia in primary position caused by motility disorders after retinal detachments treated only with encircling bands.

METHODS

A retrospective review is made of 264 consecutive patients.

RESULTS

At 6 months after surgery,18 (7%) out of the 264 patients had motility disorders with diplopia in primary position. In 55%, we found an esotropia and vertical deviation. For the treatment of diplopia, eight patients had prisms foils, five of whom are scheduled for surgery, six patients wear prism glasses and three patients did not return for follow up after their sight had been corrected with prisms. An operation for strabism was necessary in three cases, mainly because of hypertrophic scarring (adhesion syndrome), rather than suturing material or muscular decompensation. One patient needed eye occlusion for untreatable diplopia. The average change of refraction after the encircling procedure was -2.0 D.

CONCLUSIONS

We recommend avoiding unnecessary preparation of the muscles when placing the encircling band (without destruction of the Tenon or periorbital tissue), motility exercises after the operation and full refractive correction for sensory compensation of deviations as early as possible. In addition, antiphlogistic drugs should be used to avoid scarring and treatment with prism lenses. Removal of the encircling band does not seem to improve the motility as the disorder is mainly caused by hypertrophic scarring, neither does mitomycin C or the application of viscoelastic substances.