Production of tacrolimus using coconut oil as an alternative to glucose

Tacrolimus is an immunosuppressant used in the treatment of people who have undergone organ and tissue transplants, as well as in the treatment of dermatoses and eye diseases. Strategies have been carried out to increase the productivity of tacrolimus, since many compounds have in their composition tacrolimus precursors, and bacteria Streptomyces depend on a carbon source for their growth. One strategy is to change the carbon source of the fermentation medium. The present study aims to evaluate the use of coconut oil for the production of tacrolimus via Streptomyces tsukubaensis, as an alternative in the face of glucose, a traditional source of carbon. The batch fermentation process was done in an orbital shaker at 28°C and 130 rpm. Quantification of tacrolimus was performed by High Performance Liquid Chromatography (HPLC). The sugars and proteins, present in the medium, were measured from Somogyi-Nelson and Bradford methods, respectively. According to the results, coconut oil achieved the production of tacrolimus higher than glucose. This is due to the presence of a portion of monounsaturated and polyunsaturated fatty acids that act as precursors to tacrolimus. On the other hand, glucose is a quick carbon source for the bacteria and helps in its growth, but in high amounts it inhibits the production of the drug.

About free transplantation

In recent years, the issue of tissue transplants has been of great interest to surgeons, and plastic surgery has made tremendous gains. In this victorious procession of surgery, a relatively modest place is occupied by the issue of free plastic fascias.

P–451 Improving neovascularization and follicle viability in cryopreserved bovine ovarian tissue transplants

Study question Does cryopreservation and transplantation of bovine ovarian medulla-containing cortex tissue improve the viability and vascularization of the graft? Summary answer: Transplantation of bovine ovarian cortex containing medulla has a positive effect on follicular viability and neovascularization of the graft compared to cortex transplantation alone. What is known already For female fertility protection, cryopreservation and retransplantation of ovarian tissue is a widely used method. During cryopreservation, ovarian tissue is exposed to mechanical and hypoxic stress resulting in follicular loss. Moreover, after retransplantation tissue vitality and follicle survival is limited due to ischemia. As follicular viability is of major importance for fertility and hormonal activity, the main focus is on improving vitality and viability of the grafts. In current protocols, ovarian medulla is discarded and merely cortex tissue is preserved. However, medulla tissue predominantly contains blood vessels, thereby obtaining high potential for revascularization processes and thereby supporting tissue vitality. Study design, size, duration This experimental laboratory work was performed during a period of ten months. The rapidly vascularized chorioallantoic-membrane (CAM) of fertilized chicken eggs was used as model system to investigate neovascularization, follicle survival and tissue vitality of different bovine ovarian grafts. In four independent experimental rows four different tissue types (isolated cortex, thick medulla-containing cortex (8 x 10 x 3 mm), thin medulla-containing cortex (5 x 10 x 3 mm) and sole medulla tissue were compared. Participants/materials, setting, methods Out of four bovine ovaries preserved from the slaughterhouse, in total 117 samples of the four different tissue types were primed and cryopreserved by the common slow-freezing protocol. After thawing, grafts were transplanted on separate CAMs at day four of fertilized eggs. After four days of incubation, blood vessels growing towards the grafts were counted. Subsequently, grafts were harvested, digested with collagenase and stained with Neutral Red® to determine the total amount of vital follicles. Main results and the role of chance To investigate the neovascularization, all graft-supplying blood vessels were determined and distinguished between small and thick vessels. Compared to sole cortex, there were more small vessels in the medulla-containing grafts (9,72 vs. 8,65). Especially thin medulla- containing cortex pieces exhibited the highest number of small vessels (9,90). Also in isolated medulla tissue an increased amount of small vessels was observed (9,79). However, the average number of big vessels was not significantly different in all four test groups (Cortex: 2,12; thin medulla-containing cortex: 1,69; thick medulla-containing cortex: 1,5; medulla: 2). The total number of all vessels differed from 10,76 (sole cortex) to 11,75 (medulla-containing grafts), indicating a support of neoangiogenesis by medulla tissue. To further examine whether medulla tissue also alters the amount of vital follicles, Neutral Red® stained vital follicles were determined in all different sample groups. Indeed, in medulla-containing cortex samples was an augmented average number of vital follicles (342,4) compared to sole cortex tissue (256,11). Most vital follicles were detectable in the thick medulla-containing cortex tissue (346,61), closely followed by the thin medulla-containing cortex grafts (338,19). As expected, there was just a rare amount of vital follicles in sole medulla grafts (8,13). Limitations, reasons for caution As the ovarian reserve in cattle is very individual, the prepared ovaries are different in their follicle amount. These individual differences may influence the number of counted follicles. Furthermore, the CAM model is only a short term experimental approach to investigate neovascularization and follicle survival. Wider implications of the findings: According to our results, transplantation of human medulla-containing cortex appears promising. Keeping medulla tissue on the graft seems to improve both follicle viability and revascularization. Our findings need to be proven with human tissue, but might change the preparation of human ovarian tissue for fertility preservation in future. Trial registration number Not applicable

Current Challenges Facing Cornea Banks

Cornea transplants are tissue transplants and, as such, must be distinguished from organ transplants (e.g. heart or kidney transplants). However, tissue transplants can only be performed if there are enough donors available to attend to patients in need. Unfortunately, there are too few organ and tissue donors in Germany. All steps involved in processing donor tissues must be performed in accordance with the highest quality standards. All tasks and measures are aimed at improving patient care in the surgical units that are to be supplied. Cornea banks are subject to complex requirements, whose implementation is essential in terms of both infrastructure and personnel. The analysis and identification of essential topics reveal central fields of action that are decisive for implementing the challenges facing cornea banks. Questions of employee qualification, strategic questions due to new transplantation techniques, and changes in the societal perception of organ and tissue donation require the development of strategies that should have a holistic and sustainable effect.

Persistent dyskinesias in patients with fetal tissue transplantation for Parkinson disease

Cell transplants are being developed for patients with Parkinson disease (PD) who have insufficient benefit with standard medical treatment. We describe the clinical features of five patients who developed persistent dyskinesias after fetal dopaminergic tissue transplantation. All had levodopa-induced dyskinesias preoperatively. We implanted fetal mesencephalic dopaminergic tissue into the putamina bilaterally in 34 patients with advanced PD. They were not immunosuppressed. Five of 34 patients (15%) developed troublesome choreic or dystonic dyskinesias that persisted despite lowering or discontinuing medications. Attempts to treat the involuntary movements with amantadine, clozapine, anticholinergics, dopamine depletors and other medicines had limited success. Metyrosine eliminated dyskinesias but led to the parkinsonian “off” state. Increasing the dose of levodopa worsened the dyskinesias. Three patients required placement of pallidal stimulators, bilaterally in two and unilaterally in one patient who had only contralateral dyskinesias. The two with the bilateral stimulators had improvement in dyskinesias. The patient with the unilateral pallidal stimulator had a substantial reduction of the dyskinesias, but attempts to treat residual “off” symptoms with levodopa were limited by worsening dyskinesias. Although the number of patients developing these persistent dyskinesias was small, these five patients had dramatic improvement after transplant. As a group, they had milder Parkinson signs at baseline and improved to the point of having minimal parkinsonism, with reduction or elimination of levodopa therapy prior to developing persistent dyskinesias. These involuntary movements establish the principle that fetal dopaminergic tissue transplants can mimic the effects of levodopa, not only in reducing bradykinesia, but also in provoking dyskinesias.

Risk assessment in deferred and recovered donors

Serologic testing and Donor Risk Assessment Interview (DRAI) combined have made tissue transplantation a frequent and safe modality for a variety of trauma and disease conditions. Donate Life America reports 30,000 tissue donors providing more than 1,750,000 tissue transplants annually. This study of 188 potential donor cases addresses issues of risk assessment in a medical examiner population in a metropolitan area, where serologic testing of deferred potential donors were compared with the DRAI screening, which determined the suitability or non-suitability for tissue procurement. Such serologic testing of deferred cases is not usually available in evaluating screening processes. This comparison gives insight into the effectiveness of the DRAI screening in deferring potential serology reactive donors. Results show in 65 cases how the DRAI screening eliminates most, but not all of the serologically reactive donors identified post recovery. The result emphasizes the need for the combined process of DRAI screening and testing to assure transplantation safety.

21st Century Transplantation: A rational utopia?

In his Utopia, Thomas More describes a generous conception of medicine. The current reality of organ transplants, with the drama of organ shortages, waiting lists, and patient mortality, requires a conceptual review. For the success of this request, the need of parts of the human body, live or after death is essential. Without organ donation, there are no transplants. The importance of non-enrichment at any level through organ and tissue transplants has been pointed out, significantly, by monotheistic churches and the World Health Organization (WHO). The value recently given to non-cognitive factors, as well as individual behaviour in community actions, when searching for social benefits has also been discussed. This essay proposes ways to change the present critical reality. Our analysis considers education and economic aspects to be of greater significance for changing social donation behaviour.