Tissue Transplantation

1) Surveys with questionnaires distributed by centralized e-mails:
An e-mail was addressed with a similar introductory text to all employees of our university hospital (E₁), to another university hospital in southwest Germany (E₂, Homburg/Saar), and to members of a professional medical association (E₃) [12] (link). The e-mail contained a link to the Internet-based questionnaire. The questionnaires had comparable content as the aforementioned paper-based questionnaires and were made available on the Internet. The questionnaire, which contained 12 pages, comprised 12 mandatory questions. Any missing answers resulted in an electronic response to make the participant aware of the missing response. The individual's progress through the questionnaire was signified as a horizontally extending bar on top of the right-hand side of the monitor. The e-mail invitation was resent after 26 days, and the data collection was closed following the sixth week.
2) Surveys with questionnaires linked to homepage invitations:
An invitation placed on a homepage was used to contact the municipal employees of our city (H₁) and those of an industrial city in the center of Germany (H₂, Essen). Comparable to the paper-based version, an introductory text regarding matters of organ and tissue transplantation and donation and of the use of the questionnaire was placed at the top of the municipal homepage that regularly appeared when the computer was started. A link was placed in this text that took the participant directly to the survey and was visible for six complete weeks.
Both electronic surveys (centralized e-mails and homepage link) were randomized automatically with the EFS Survey software.
The electronic and paper-based surveys were compared for their question formats and the possibility of randomization. The surveys were also compared with regard to the demographic data and number of potential and effective participants, the time taken to answer all questions, the number of incompletely and completely answered questionnaires, the point in a survey at which the participant abandoned it in partial completion, the time taken to design and implement the survey, and the efficacy of the survey regarding time and financial costs. Complete answering was defined as having responded to the final question of the questionnaire.
To measure the mean time for completing the paper-based questionnaire, the time required to answer the questionnaire was measured in 30 participants in a pilot study. The necessary time for answering the Internet questionnaires was automatically registered with the Survey (QuestBack GmbH, Hürth, Germany).
Based on our observed ratios of potential participants and completely answered questionnaires, the cost and time for surveys with estimated complete questionnaires were calculated for surveys with 10, 20, 30, or 42 questions of the same format.

Graft vein tissues were fixed in 4% paraformaldehyde for 24 h, embedded in paraffin wax, and cross-sectioned into 4 μm sections. Tissue sections were placed on an electric heating plate at 60–70 °C for 3–4 h, followed by dewaxing using xylene for 15 min at room temperature (20–25 °C). Dewaxing was completed after two repetitions. The sections were subsequently hydrated in a gradient of decreasing ethanol and washed with tap water for 5 min to remove excess ethanol. Sections were then H&E and Masson stained to examine the structural changes and degree of hyperplasia of the graft vein. The stained sections were observed under a light microscope (magnification, ×100; Leica, Wetzlar, Germany). The thickness of the intima and media was measured using ImageJ, and the intima/media ratio was calculated simultaneously. Three different parts of each sample were randomly selected for measurement, and the average value was calculated.
For H&E staining (Shanghai Biyuntian Biotechnology Co., Ltd., cat. no. C0105S), the sections were stained with hematoxylin for 4–5 min and washed with tap water for 5 min. The sections were placed in a hydrochloric acid-ethanol fast differentiation solution (Shanghai Biyuntian Biotechnology Co., Ltd., cat. no. C0163S) for 10 s and washed with water for 5 min. The hydrated tissue sections were again immersed in an eosin staining solution for 3 min. The sections were subsequently dehydrated using graded increments of ethanol and coverslips were fixed with neutral gum.
For Masson staining (Beijing Solarbio Technology Co., Ltd., cat. no. G1340), sections were stained with Ponceau S dye for 5 min and washed with tap water for 5 min. The sections were incubated with 1% phosphotungstic acid solution for 5 min and then stained with aniline blue dye for 5 min. Subsequently, they were incubated with 1% glacial acetic acid in water for 1 min, dehydrated with graded increments of ethanol, and fixed with neutral gum.

After obtaining the approval of Uludağ University Faculty of Medicine Non-Interventional Research Ethics Committee (decision no: 2011-KAEK-26/165), the study included patients admitted to the anesthesia intensive care unit of Private Medicabil hospital for intracranial bleeding with a Glasgow coma score below 7 between 01 January 2019 and 01 February 2022. The patients were divided into two separate groups: Group BD (patients with brain death) and Group ICH (patients with intracranial hemorrhage without brain death). In Group BD, according to the Ministry of Health regulation for organ and tissue transplantation, the absence of brainstem reflexes, a coma status that has been confirmed not to be induced by hypothermia or drugs, and a positive apnea test result were evaluated in favor of the diagnosis of brain death. To perform the apnea test, the patient was disconnected from the mechanical ventilator and administered intratracheal oxygen to prevent the auto-triggering of cardiac origin after providing normothermia, normotension, normovolemia, and PaCO₂ of 35 to 45 mm Hg and PaO2 of >200 mm Hg. The apnea test was considered positive if spontaneous breathing was absent despite a PaCO₂ value ≥60 mm Hg and/or an increase in PaCO₂ of 20 mm Hg or more from baseline at the end of the test. The patients underwent cerebral CT angiography to confirm brain death and to detect the absence of intracranial blood flow. The patients without intracranial blood flow were considered brain dead [1 ]. The patients who died in the intensive care unit due to intracranial hemorrhage and who did not have brain death were included in the ICH group. The patients who had sequelae of a previous cerebrovascular accident, 24 h after the onset of the cerebrovascular accident, patients with a history of infection 2 weeks before hospitalization or with signs of infection during hospitalization, patients with malignancy, immunodeficiency, immunotherapy, or severe coronary artery disease, and patients who died due to secondary infection were not included in the study. The blood parameters of neutrophil, lymphocyte, platelet, and monocyte analyzed to evaluate the condition of patients at admission to the intensive care unit were recorded. The patients’ demographic data and indications for hospitalization were recorded as well.