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At least 181 records · Page 10Linked to original sources
PubMed2006

University of Wisconsin versus histidine-tryptophan-ketoglutarate for tissue preservation in live-donor liver transplantation.

OBJECTIVES: University of Wisconsin solution has twice the cold hepatic preservation time as does Euro-Collins solution. Histidine-tryptophan-ketoglutarate has a lower potassium content than does University of Wisconsin solution and is used more frequently. To date, however, studies comparing University of Wisconsin and histidine-tryptophan-ketoglutarate in live-donor liver transplantation are lacking. We therefore sought to examine the hepatic function of live-donor liver transplantation allografts preserved in University of Wisconsin solution as compared with those preserved in histidine-tryptophan- ketoglutarate solution. MATERIALS AND METHODS: Between July 2003 and August 2004, 33 live-donor liver transplantations were performed at the University of Rochester Medical Center, Rochester, NY, USA. University of Wisconsin solution was used for the first 9 allografts, and histidine-tryptophan-ketoglutarate was used for the subsequent 24 allografts. Daily total bilirubin, aspartate amino transferase, amino alanine transferase, alkaline phosphatase, gamma glutamyl transpeptidase, and international normalized ratio levels were measured for the first 8 postoperative days. Peak values were compared between the groups. RESULTS: There was no primary graft nonfunction in either group. Two patients in the histidine-tryptophan- ketoglutarate group developed hepatic artery thromboses and underwent a retransplantation. Mean peak aspartate amino transferase and amino alanine transferase levels were higher in patients in the histidine-tryptophan-ketoglutarate group (aspartate amino transferase, 661+/-801 U/L; amino alanine transferase, 696+/-964 U/L) than they were in patients in the University of Wisconsin group (aspartate amino transferase, 439+/-415 U/L; amino alanine transferase, 464+/-376 U/L); however, this difference was not significant. Mean total bilirubin, alkaline phosphatase, and gamma glutamyl transpeptidase levels, and international normalized ratios were similar in both groups. CONCLUSIONS: University of Wisconsin and histidine-tryptophan- ketoglutarate solutions are both effective in preserving live-donor liver allografts. In the current study, patients in the histidine-tryptophan-ketoglutarate group had higher peak aspartate amino transferase and amino alanine transferase levels initially, but these became almost identical by postoperative day 8.

Adenosine↗
PubMed1994

Histoenzymatic study of human renal tissue preservation: I--Proximal tubular glucose-6-phosphatase is correlated with transplant evolution.

Glucose-6-phosphatase was tested histochemically as a gluconeogenesis marker of ischemia-reperfusion injury of proximal tubular cells in human renal transplants. Histochemical enzyme activity, histology and transplantation conditions (preservation solution, cold and warm ischemia time, donor age), were compared to renal transplant evolution. Neither histology nor transplantation conditions were correlated with renal transplant evolution. Only glucose-6-phosphatase activity was significantly correlated with transplant evolution and could be used as a more sensitive marker than histology for the detection of ischemia-reperfusion injury of proximal tubules.

Adult↗
PubMed1993

Lining of viable and nonviable allogeneic and xenogeneic cardiovascular tissue with cultured adult human venous endothelium.

With the aim of creating a confluent endothelial lining of cultured adult human saphenous vein endothelial cells on cardiovascular bioprosthetic tissues in vitro, we performed seeding on deendothelialized segments of viable or devitalized (in deionized water) human vein, porcine aorta, and bioprosthetic tissues preserved in glutaraldehyde. After being seeded, specimens were kept for 7 days under culture conditions. On glutaraldehyde-preserved tissue, seeding was performed after 3 weeks of elution of glutaraldehyde. Evaluation was performed with hematoxylin-eosin staining, immunohistochemical staining of von Willebrand's factor and of collagen IV-related antigens, and scanning and transmission electron microscopy. The origin of the cells as derived from culture was verified by vital staining with a carbocyanine dye. Evaluation revealed a confluent lining of cultured human saphenous vein endothelial cells similar to native endothelium on both viable and nonviable human and porcine tissues. Collagen IV-related immunoreactivity was demonstrated close to the endothelial cells, corresponding to a de novo-formed basement membrane. Organelles and a basement membrane were demonstrated by transmission electron microscopy. The human saphenous vein endothelial cells seeded on glutaraldehyde-preserved tissues showed initial adherence but rounded up and detached on the second day of culture, probably because of residual glutaraldehyde. This study demonstrates that the native endothelium of allogenic or xenogeneic viable and nonviable vascular tissue may be replaced by cultured endothelium in vitro. The structural similarities with a native endothelium suggest that in vitro endothelialization with cultured autologous endothelial cells may be used to improve performance of cardiovascular bioprostheses.

Adult↗
PubMed1992

Electron microscopical demonstration of horseradish peroxidase by use of tetramethylbenzidine as chromogen and sodium tungstate as stabilizer (TMB-ST method): a tracing method with high sensitivity and well preserved ultrastructural tissue.

Until now methods using tetramethylbenzidine (TMB) for electron microscopy (TMB-EM methods) are all unable to provide a maximum demonstration of transported horseradish peroxidase (HRP) while maintaining good ultrastructural tissue preservation. In order to solve this problem, we have attempted to adapt a newly developed, highly sensitive TMB method using sodium tungstate (ST) as the stabilizer (TMB-ST method) for HRP electron microscopic retrograde and anterograde fiber tracing. The present study shows that the TMB-ST method combined with diaminobenzidine-cobalt (DAB-Co) is more sensitive than existing TMB-EM methods and that ultrastructural details are well preserved with this combined method. The resultant reaction product complex after osmication is stable and is observed as characteristic crystal-like structures which are extremely electron dense and often aggregated into clumps. In contrast, the TMB-ST method without the DAB-Co step frequently produces a moderate electron-dense reaction product. Therefore, we recommend the TMB-ST method combined with DAB-Co for HRP electron microscopy.

3,3'-Diaminobenzidine↗
PubMed1993

Localization of secretory, membrane-associated and cytoskeletal proteins in rat testis using an improved immunocytochemical protocol that employs polyester wax.

Immunocytochemistry is a compromise between maintaining antigenicity and preserving tissue morphology. In the testis, successful immunostaining results at the level of resolution provided by the light microscope have been obtained through use of either frozen or paraffin sections, although both techniques are fraught with limitations. With freezing, tissue preservation is not optimum, whereas with paraffin embedding, antigenicity is often destroyed. These limitations are not trivial and have led to numerous ambiguous results in the literature. In the present study we wish to report the results of immunocytochemical localization of various proteins in testis fixed by perfusion with Bouin's fluid and embedded in polyester wax, a ribboning embedding medium for histology. The advantages of this medium are that it does not require clearing of tissues in xylene solvents before embedding and that unlike paraffin, it liquifies at 38 degrees C. Because of these two properties, the polyester was appears to adequately maintain antigenicity as compared to that observed in frozen sections, yet because it is a ribboning wax, it preserves detailed structure as well as paraffin does. Proteins that were immunolocalized included cytoskeletal proteins (tubulin, actin, vinculin, vimentin) and cell-specific markers: 1) androgen-binding protein (ABP) for Sertoli cells; 2) peripheral type benzodiazepine receptor (PBR) for Leydig cells; and 3) nuclear lamins for germ cells. Biotin-streptavidin peroxidase immunocytochemistry was employed to determine the specific distribution of the various proteins, and both rabbit antisera and mouse monoclonal antibodies were used with equal success. In addition, fluorochrome-labeled second antibodies combined with confocal microscopy were used to examine the disposition of the antigens in the testis. Results revealed maintenance of antigenicity and morphology far superior to that obtained with paraffin and frozen sections, respectively, they also showed that within the seminiferous epithelium, germ cell or Sertoli cell-specific proteins were unambiguously immunolocalized to their respective cells. Specific observations made possible through use of this protocol suggest that neither tubulin or vimentin immunostaining patterns in Sertoli cells are altered during the cycle of the seminiferous epithelium. Similarly, ABP staining appeared constant throughout the cycle. Further, we wish to report that anti-PBR is a specific probe for Leydig cells in vivo and that an anti-nuclear lamin antibody appears to serve as a specific probe for spermatogonia and pachytene spermatocytes, but that the commercially available anti-smooth muscle alpha-actin monoclonal antibody immunostains both the myoid and lymphatic endothelial cells forming the peritubular cells layer of the seminiferous tubule.(ABSTRACT TRUNCATED AT 400 WORDS)

Androgen-Binding Protein↗
PubMed2002

Retrieval of mRNA from paraffin-embedded human infant brain tissue for non-radioactive in situ hybridization using oligonucleotides.

In situ hybridization (ISH) is used to examine the spatiotemporal distribution of gene expression in a range of tissues. Neuroscience research in human brain tissue requires techniques that can be used in formalin fixed and paraffin-embedded tissue rather than frozen tissue which is recommended, but difficult to obtain. This study presents a method for non-radioactive (DIG) ISH for detecting NR1 gene expression, in human infant brain tissue. We compared three pre-treatment effects, protease digestion, autoclaving (in citrate and Tris/EDTA buffer) and microwaving (in citrate and Tris/EDTA buffer). Tissue had been fixed in formalin for 2-12 weeks. Results were compared for the hybridization and background signal intensities, and tissue morphology. We found that optimum results were obtained using 12-min microwave pre-treatment in Tris/EDTA buffer. This method produced optimum signal to background ratio in infant and adult tissue, preserved tissue morphology, and was suitable for use across a broad range of fixation times.

Aged↗
PubMed2025

Real-world deployment of a fine-tuned pathology foundation model for lung cancer biomarker detection.

Artificial intelligence models using digital histopathology slides stained with hematoxylin and eosin offer promising, tissue-preserving diagnostic tools for patients with cancer. Despite their advantages, their clinical utility in real-world settings remains unproven. Assessing EGFR mutations in lung adenocarcinoma demands rapid, accurate and cost-effective tests that preserve tissue for genomic sequencing. PCR-based assays provide rapid results but with reduced accuracy compared with next-generation sequencing and require additional tissue. Computational biomarkers leveraging modern foundation models can address these limitations. Here we assembled a large international clinical dataset of digital lung adenocarcinoma slides (N = 8,461) to develop a computational EGFR biomarker. Our model fine-tunes an open-source foundation model, improving task-specific performance with out-of-center generalization and clinical-grade accuracy on primary and metastatic specimens (mean area under the curve: internal 0.847, external 0.870). To evaluate real-world clinical translation, we conducted a prospective silent trial of the biomarker on primary samples, achieving an area under the curve of 0.890. The artificial-intelligence-assisted workflow reduced the number of rapid molecular tests needed by up to 43% while maintaining the current clinical standard performance. Our retrospective and prospective analyses demonstrate the real-world clinical utility of a computational pathology biomarker.

Humans↗
PubMedDate not supplied

Qualitative and quantitative histomorphologic assessment of fathead minnow Pimephales promelas gonads as an endpoint for evaluating endocrine-active compounds: a pilot methodology study.

Although histopathology is routinely employed as a tool for the detection and assessment of xenobiotic-mediated effects in mammals, it is less frequently applied to fish. In part, this is due to a lack of method standardization regarding study design, tissue preservation, tissue sectioning, histopathological evaluation, reporting, and statistical analysis. The objectives of the present study were: (1) to test and refine a method for the microsurgical excision of fathead minnow (FHM) Pimephales promelas gonads for the purpose of histopathologic examination; (2) to determine the optimal combination of fixation and embedding procedures for the histopathologic and morphometric analysis of FHM gonads following exposure to a known estrogenic compound, 17beta-estradiol (E2); and (3) to provide a method for the categorization and quantification of cell types in FHM gonads by manually counting cells in digitized images using image analysis software. The light microscopic evaluation of individual gametogenic cells was greatly facilitated by specimen preparation techniques that included the excision of gonads via microdissection and by optimized fixation and embedding procedures.

Animals↗
PubMed1998

Natural history of the spontaneous reperfusion of human cerebral infarcts as assessed by 99mTc HMPAO SPECT.

OBJECTIVE: Little is known about the effect of spontaneous reperfusion of human cerebral infarcts. Single photon emission computerised tomography (SPECT) data were analysed from a study using 99Tc(m) HMPAO (99Tc(m) hexamethylpropyleneamine oxime) in human cerebral infarction for the frequency of reperfusion and to see if it affected infarct size, oedema, haemorrhagic transformation, or functional outcome. METHODS: Fifty sequential cases of ischaemic stroke were studied with 124 99Tc(m) HMPAO SPECT at around one day, one week, and three months after stroke along with detailed clinical and functional assessments. RESULTS: Visually apparent reperfusion occurred in 14 of 50 patients (28%) with a mean delay of 5.8 days and reperfusion was seen in seven others in whom it was identified on the basis of changes in perfusion deficit volume. It occurred in 13 of 23 embolic events but only in three of 23 other events. In only two cases did spontaneous reperfusion occur early enough to preserve tissue or function. Reperfusion did not otherwise reduce infarct size, or improve clinical or functional outcome, and was not associated with oedema but an association with haemorrhagic transformation was suggested. Reperfusion significantly decreased the apparent perfusion defect as measured by SPECT one week from the ictus, but was mostly non-nutritional and transient. The mean volume of tissue preserved by nutritional reperfusion was 10 cm3, but this was unequally distributed between cases. Late washout of 99Tc(m) HMPAO from areas of hyperaemic reperfusion may be a good prognostic marker but is a rare phenomenon and too insensitive to be of general applicability. CONCLUSIONS: Spontaneous reperfusion after cerebral infarction occurs in 42% of cases within the first week but is associated with clinical improvement in only 2%. It has few adverse consequences although it may be associated with haemorrhagic transformation.

Activities of Daily Living↗
PubMed2006

The preservation of tissues for transplantation.

This paper is a written version of a lecture given during the celebration of Professor Rudolf Klen's 90th birthday. Dr. Klen played by far the major part in the introduction and the development of Tissue Banking in Europe. His concept of a tissue bank envisaged the storage of all types of cell, tissue and organ that physicians and surgeons might need for the treatment of their patients. There has been much progress towards this goal, but still the final objective remains elusive. This review of the current position starts with the recognition that some tissues are required to comprise or include cells that exhibit all the formal characteristics of life if they are to function as grafts, whereas other tissues do not. For some tissues, the preservation of mechanical properties is crucial: for others it is not. These considerations are crucial for the design of preservation methods for specific tissues: bone tendon and skin can provide useful grafts in the absence of living cells and this may even be true of cardiac valves: the crucial requirement here is that the mechanical properties remain intact. Simply freezing at around -80 degrees C may be sufficient. In contrast, many cell systems, and all metabolizing organs do require healthy cells to function. Cryopreservation is often an effective remedy for isolated cells, for example haemopoietic stem cells, but the damaging effects of the formation of ice are sufficient to rule out this approach for whole vascularised organs and for some tissues too. The damaging mechanisms are discussed, and it is concluded that the site of ice crystallization is crucial. Cartilage has hitherto been recalcitrant, but we have recently developed a method that permits this tissue to be stored at liquid nitrogen temperatures without any ice and with the recovery of living cells and intact mechanical properties after storage. Thus, many methods are available to help develop tissue banking originally envisioned by Dr. Klen.

Cell Survival↗
PubMed1978

Insulin-releasing activity and successful transplantation of pancreatic islets preserved by tissue culture.

Preserving pancreatic islets for 7 days by a making use of the organ culture, we studied the insulin-releasing activity at the time of administration of glucose and various digestive tract hormones for the purpose of clarifying the function of preserved pancreatic islets. Furthermore, we transplanted pancreatic islets preserved for 3 to 5 days into the portal vein of rats with streptozotocin-induced diabetes and reached the following conclusions: (1). The islets of Langerhans of the pancreas responded well to glucose up to the seventh day of preservation and showed patterns similar to those of fresh pancreatic islets with respect to both the dose response and the time response. (2). Preserved pancreatic islets of the pancreas had insulin-releasing activity almost equal to that of fresh pancreatic islets against stimulation by glucagon, tolbutamide, and various digestive tract hormones. (3). Rats with streptozotocin-induced diabetes showed a marked improvement in blood glucose and urine glucose following transplantation of preserved pancreatic islets into the portal vein, and this effectiveness persisted for 6 to 8 weeks.

Animals↗
PubMed1997

Increased epinephrine-induced cAMP response in severely diabetic BB/W rat liver.

The effect of prolonged diabetes on epinephrine-induced adenosine 3',5'-monophosphate (cAMP) response in the liver was examined in diabetes-prone BB/W rats. Basal and 1 microM epinephrine-induced cAMP release from isolated perfused liver was similar in non-diabetic and diabetic BB/W rats with preserved adipose tissue. In adipose tissue-absent diabetic rats losing intra- and retro-peritoneal adipose tissue completely, both basal and 1 microM epinephrine-induced cAMP release from the liver were enhanced (P<0.01, each case). Plasma epinephrine and norepinephrine were similar in non-diabetic, adipose tissue-preserved and -absent diabetic BB/W rats. The plasma free thyroxine level was similar in non-diabetic and adipose tissue-preserved diabetic BB/W rats, but was lower in adipose tissue-absent diabetic BB/W rats than in non-diabetic rats (P<0.01), but the frequency of lymphocytic thyroiditis was similar in these three groups, although plasma corticosterone was lower in adipose tissue-preserved diabetic BB/W rats (P<0.05) and the lowest in adipose tissue-absent diabetic BB/W rats (P<0.01). Lymphocytic infiltration was not observed in the adrenal or pituitary glands in any group. Plasma total protein and albumin were low in adipose tissue-absent diabetic BB/W rats (P<0.01, each case). In adipose tissue-absent diabetic BB/W rats, liver dysfunction and hepatomegaly, but no apparent histological change in the liver, were observed. Plasma glucose was higher (P<0.01) and plasma insulin lower (P<0.05) in adipose tissue-absent diabetic BB/W rats than in adipose tissue-preserved diabetic BB/W rats. In conclusion, epinephrine-induced cAMP response in the liver was enhanced only in adipose tissue-absent diabetic BB/W rats. Denervation supersensitivity was not likely to be responsible for the enhanced beta-adrenergic response. The observed reductions in plasma thyroxine and corticosterone seemed to result from severe diabetes. Although the severity of diabetes can vary continuously, severe diabetes with loss of adipose tissue appeared to cause significant changes in the metabolism and enhanced beta-adrenergic response in the liver.

Alanine Transaminase↗