Allogeneic hepatocyte transplantation using FK 506.

Hepatocyte transplantation is an intriguing alternative to orthotopic liver transplantation. While engraftment of syngeneic hepatocytes can be achieved with relative ease, engraftment of allogeneic hepatocytes has been far more complicated. We used FK 506 (Tacrolimus), a novel and highly efficient immunosuppressant, which has been reported to augment liver regeneration in rats. Recipients of isolated syngeneic (LEW) and allogeneic (Wistar F.) rat hepatocytes (major histocompatibility barrier) recieved different immunosuppressive regiments with FK 506 or Cyclosporine A (CsA). Mature syngeneic hepatocytes could be retrieved up to post op day 300 with the lowest number of hepatocytes on post op day 20. Following allogeneic transplantation, no mature hepatocytes could be identified after post op day 10, though ductular like structures within the spleen were found in FK 506 but not CsA-treated animals. The epithelial cells of ductular like structures exhibit cytological features of CK-19 positive cells. Our results suggest that under CsA or FK 506 immunosuppression long-term survival of mature allogeneic hepatocytes within the spleen cannot be achieved across a major histocompatibility barrier though FK 506 allows engraftment of allogeneic donor type ductular cells.

[Is scleral buckling still current?]. / Ist die Buckelchirurgie noch aktuell?

We report a survey among German-speaking vitreo-retinal surgeons, considering their decisive factors and preferred surgical techniques in simple and complicated rhegmatogenous situations. In cases of simple retinal detachment conventional buckling surgery is the favoured surgical approach. Minimal-invasive techniques like the balloon operation or pneumatic retinopexy are chosen by less than 5% of the surgeons. For more complicated retinal detachments a strong trend towards primary vitrectomy becomes apparent. In difficult rhegmatogenous situations which are still treatable with conventional buckling procedures, 45% of surgeons prefer a primary vitrectomy and only 55% chose scleral buckel or encircling band procedures.

Quality of salivary tears following autologous submandibular gland transplantation for severe dry eye.

BACKGROUND: This study aimed to characterise the composition of the pre-ocular fluid after transplantation of the autologous submandibular gland (SMG) for patients with severe dry eye. METHODS: Stimulated and unstimulated pre-ocular fluid from 15 patients (17 eyes) with a viable SMG graft ("SMG-salivary tears"), as well as normal tears and SMG saliva (20 normal subjects/ 20 eyes), was sampled. As global tear parameters, fern pattern analysis and SDS gel electrophoresis were performed. As specific quality parameters, total protein content, secretory immunoglobulin A (SIgA), lysozyme, amylase, sodium, potassium and osmolality were measured using routine laboratory methods. The flow rate of SMG-salivary tears was determined in 5 patients by means of sequential scintillography. RESULTS: The fern pattern of SMG-salivary tears was coarse and thus more similar to normal SMG saliva than tears. SDS gel electrophoresis of the SMG-salivary tears showed albumin and two unidentified proteins in addition to the normal tear pattern. Osmolality and total protein content of SMG-salivary tears were higher than in normal SMG saliva, but still lower than in normal tears. High activities of normal tear antibacterial proteins (SIgA, lysozyme and amylase) were detected in the salivary tears. Stimulation of the secretion did not alter the composition of SMG-salivary tears. The flow rate of SMG-salivary tears was closer to that of normal tears than normal SMG saliva. CONCLUSION: Salivary tears resulting from SMG-transplantation represent condensed SMG saliva. Thus their quality is intermediate between normal tears and normal SMG saliva. High levels of secretory proteins demonstrate that the gland maintains an active function. Surgical denervation and residual tear components from the ocular surface are the most likely factors to cause the complex differences between normal SMG saliva and SMG-salivary tears. The effects of this secretion on the ocular surface are currently being evaluated in a clinical and laboratory study.

Quality of salivary tears following autologous submandibular gland transplantation for severe dry eye.

BACKGROUND: This study aimed to characterise the composition of the pre-ocular fluid after transplantation of the autologous submandibular gland (SMG) for patients with severe dry eye. METHODS: Stimulated and unstimulated pre-ocular fluid from 15 patients (17 eyes) with a viable SMG graft ("SMG-salivary tears"), as well as normal tears and SMG saliva (20 normal subjects/20 eyes), was sampled. As global tear parameters, fern pattern analysis and SDS gel electrophoresis were performed. As specific quality parameters, total protein content, secretory immunoglobulin A (SIgA), lysozyme, amylase, sodium, potassium and osmolality were measured using routine laboratory methods. The flow rate of SMG-salivary tears was determined in 5 patients by means of sequential scintillography. RESULTS: The fern pattern of SMG-salivary tears was coarse and thus more similar to normal SMG saliva than tears. SDS gel electrophoresis of the SMG-salivary tears showed albumin and two unidentified proteins in addition to the normal tear pattern. Osmolality and total protein content of SMG-salivary tears were higher than in normal SMG saliva, but still lower than in normal tears. High activities of normal tear antibacterial proteins (SIgA, lysozyme and amylase) were detected in the salivary tears. Stimulation of the secretion did not alter the composition of SMG-salivary tears. The flow rate of SMG-salivary tears was closer to that of normal tears than normal SMG saliva. CONCLUSION: Salivary tears resulting from SMG-transplantation represent condensed SMG saliva. Thus their quality is intermediate between normal tears and normal SMG saliva. High levels of secretory proteins demonstrate that the gland maintains an active function. Surgical denervation and residual tear components from the ocular surface are the most likely factors to cause the complex differences between normal SMG saliva and SMG-salivary tears. The effects of this secretion on the ocular surface are currently being evaluated in a clinical and laboratory study.