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PubMed1998

Preliminary results comparing the recovery of basic fibroblast growth factor (FGF-2) in adipose tissue and benign and malignant renal tissue.

PURPOSE: Basic fibroblast growth factor (bFGF or FGF-2) is mitogenic to numerous epithelial, mesodermal and endothelial cells, and thus may play a role in the neovascularity and progression of several tumors. Furthermore, FGF-2 is reported to be elevated in the serum and urine of patients with various cancers, including renal cancer. Obesity, with increased body fat, is a risk factor for renal cancer through unknown mechanisms. Since adipose tissue is a source of FGF-2, we determined the quantity and quality of activity of FGF-2 in omental adipose tissue and compared it to normal and cancerous renal tissue. MATERIALS AND METHODS: Using heparin-Sepharose chromatography we extracted proteins from human omental adipose tissue, renal cell carcinoma (RCC) and benign renal tissue (BRT). Using FGF-2 antisera we performed western blot analysis to confirm their homology to FGF-2. We also assessed recovery, mitogenicity and angiogenicity of each of the proteins using thymidine incorporation into human umbilical vein endothelial cells (HUVEC) and the chorioallantoic membrane (CAM) assay. RESULTS: Each of the three purified mitogenic proteins eluted with NaCl concentrations between 1.4 M. and 1.8 M., similar to control FGF-2. There was greater recovery of FGF-2 from omental adipose tissue compared with renal cell carcinoma or benign renal tissue (42 microg. vs. 24 microg. and 18 microg., respectively; ANOVA p <0.05). Moreover, FGF-2 from adipose tissue had greater mitogenic activity (96.% versus 68% and 38%; p <0.05) and greater angiogenic activity (5.5 vessels versus 2.7 and 1.6 vessels; p <0.05) on the CAM assay. CONCLUSIONS: We suggest that human omental adipose tissue FGF-2 may demonstrate greater mitogenic and angiogenic activity than either benign or cancerous renal tissue FGF-2. It is not known if FGF-2 from adipose tissue may play a role in the relationship between obesity and renal cancer.

Adipose Tissue↗
PubMed1997

Tissue-specific expression and promoter analyses of the human tissue kallikrein gene in transgenic mice.

The expression of the tissue kallikrein gene is tissue-specific and exhibits a complex pattern of transcriptional and post-translational regulation. Information concerning the mechanism of its tissue-specific expression has been limited owing to the lack of suitable cell lines for the expression study. We approached this problem by introducing human tissue kallikrein gene constructs into mouse embryos, creating transgenic lines carrying its coding sequence with varying lengths of the promoter region. One construct (PHK) contained 801 bp in the 5'-flanking region and two deletion constructs contained either 302 bp (D300) or 202 bp (D200) of the promoter region. The expression of human tissue kallikrein in these transgenic mice was monitored by Northern blot, reverse transcriptase-PCR followed by Southern blot, and radioimmunoassay. In all three lines, human tissue kallikrein was expressed predominantly in the pancreas and at lower levels in other tissues, including salivary gland, kidney and spleen. This pattern was similar to that of tissue kallikrein expression in human tissues. The D300 line has higher levels of transgene expression than the D200 and PHK lines. The results indicate that the 202 bp segment immediately upstream of the translation starting site is sufficient to direct a tissue-specific expression pattern of the human tissue kallikrein gene, and that regulatory elements might exist between -801 and -202.

Animals↗
PubMed1995

[Tissue engineering: artificial tissue replacement containing vital components].

Tissue engineering as a new field of research has gained increasing importance in recent years. The interdisciplinary field combines, biomaterials cell biology, and cell culture bio-engineering technology. The main focus of tissue engineering is the synthesis of artificial constructs or tissues based on vital cells or cell matrix. Biomaterials provide a three-dimensional structure to shape or guide tissue development. Isolated cartilage cells from a patient can form new tissues when suspended in non-woven resorbable polymers for reconstructive surgery. To achieve sufficient amounts of autologous cells for transplant formation, cells from biopsies have to be multiplied in monolayer culture. Dedifferentiated and undifferentiated mesenchymal cells may be used for bone and cartilage engineering. High cell densities in three-dimensional cultures require perfusion techniques to stabilize culture conditions. Morphogenetic factors such as BMP (bone morphogenetic protein) are thought to play a key role in inducing and controlling phenotypic tissue formation. In conclusion, modern in vitro approaches open new avenues for the development of vital tissue replacements for the clinic. Tissues can be repaired with the patient's own cells eventually leaving no residual artificial materials. Tissue engineering further provides new approaches for in vitro models of the extracellular matrix or diseases which mainly affect this matrix such as rheumatoid arthritis or osteoarthritis. This article describes recent developments in connective tissue engineering and discusses the potential for human tissue repair and reconstructive surgery.

Animals↗
PubMed2001

Tissue microarray technique in soft tissue sarcoma: immunohistochemical Ki-67 expression in malignant fibrous histiocytoma.

Malignant fibrous histiocytoma (MFH) represents a heterogeneous soft tissue sarcoma entity. The authors compared different methods to determine immunohistochemical staining in whole tissue sections, evaluated the tissue microarray technique, and assessed immunohistochemical heterogeneity using the proliferation marker Ki-67 in 47 histopathologic tumor blocks from 11 MFHs. Whole tissue sections were assessed counting 400 cells along a line and counting all cells in 10 high-power fields (0.16 mm2) with mean Ki-67 expression levels of 13% and 11%, respectively. For the tissue microarray technique, two to three 0.6-mm diameter biopsies were studied from each of the 47 tumor blocks. Good correlation was obtained between whole tissue immunohistochemistry and tissue microarray with the microarray method, giving on average 8.6% greater Ki-67 expression levels than the reference method. Immunohistochemical tumor heterogeneity, evaluated using the high-power field method, showed a median standard deviation of 2.3% within the tumor blocks and 2.5% between the blocks from the same tumor. The authors concluded that the tissue microarray technique yields good quality staining and expression levels for Ki-67 comparable with whole tissue methods in MFH, but because of tumor heterogeneity, several tumor blocks ideally should be studied and, because of loss of material in the microarray process, multiple biopsies should be taken. The feasibility of tissue microarray for immunohistochemical studies of soft tissue sarcomas offers new possibilities to study multiple markers in large tumor materials.

Aged↗
PubMed1981

Effect of D-penicillamine on collagen, glycosaminoglycans, DNA and RNA of granulation tissue and connective tissue of skin, bone and aorta in rats.

Granulation tissue was produced by subcutaneous implantation of viscose-cellulose sponges on rats. The effect of D-penicillamine 500 mg/kg/day for 10 days on granulation tissue and the connective tissue of skin, bone and aorta was studied ny comparison of treated animals with operated and unoperated controls. In addition, the effect of sponge implantation on intact tissues was studied by comparison between the control groups. The amount of granulation tissue was not affected by D-penicillamine, and the granulomas-DNA content even increased. D-penicillamine increased the amount of salt soluble collagen in all tissues consistent with an inhibition of collagen crosslinking as reflected by increased aldehyde content and alpha/beta chain ratio in soluble skin collagen. Skin appeared to be most sensitive. The content of free hydroxyproline and RNA and the RNA/DNA ratio in skin decreased suggesting a decreased collagen biosynthesis. The hydroxylation of proline and lysine was not affected by the treatment. The water percentage of aorta increased during D-penicillamine treatment, and the 35S-sulphate uptake in the sulphated glycosaminoglycans was stimulated in all tissues, in granulation tissue mainly in the chondroitin-4/6-sulphate fraction. No quantitative glycosaminoglycan changes occurred in granulation tissue. Sponge implantation caused an increase in the amount of salt soluble skin collagen without any change in alpha/beta chain ratio and aldehyde content of purified, soluble collagen. D-penicillamine plus operation reduced the collagen content of aorta. The effects of D-penicillamine on connective tissue compounds may be of importance for its antirheumatic efficacy, but the accompanying effect on normal tissues may imply side effects.

Animals↗
PubMedDate not supplied

A comparison using tissue electrical properties and temperature rise to determine relative absorption of microwave power in malignant tissue.

This paper compares two methods for determining the radio frequency absorbed power in tissue: from the measured electrical properties of the tissue, and from the induced temperature rise per unit time. In previous research, we measured the ratio frequency electrical properties of muscle, mammary gland, and malignant mammary tissue (SMT-2A mammary adenocarcinoma) in female W/Fu isogeneic rats. From those measurements we calculated for each tissue the power absorption versus frequency, and formed the ratio of malignant-to-normal power absorption. This ratio exhibited a peak within the 150 to 400 MHz range, indicating a selective absorption of power in this type of malignant tissue over that of the normal host tissue. In the present study, by an entirely different method, we have directly tested the results of our earlier research. We filled a 20-cm-long section of rigid coaxial line (ordinarily air filled) with either normal (beef muscle or fat) or malignant (SMT-2A) tissue, and measured the temperature increase versus time at the irradiated tissue surface for the same absorbed power in each tissue type. We made the measurements from 50 to 915 MHz, and found that the initial temperature increase per second per watt absorbed (dT/dt/Pa) was greater in malignant tissue than in muscle or fat at each frequency tested, with the greatest differences occurring below 450 MHz. Power absorption based on the measured values of dT/dt/Pa was again greatest for the malignant tissue (SMT-2A mammary adenocarcinoma) within the 150 to 400 MHz range.

Adenocarcinoma↗
PubMed1996

Fibrin deposition in tissues from endotoxin-treated mice correlates with decreases in the expression of urokinase-type but not tissue-type plasminogen activator.

The primary hypothesis of this report is that the formation and subsequent removal of fibrin in specific tissues during pathologic processes reflects temporal changes in the local expression of key procoagulant and fibrinolytic genes. To begin to test this hypothesis, we have used quantitative PCR assays and in situ hybridization analysis to examine the effects of endotoxin on the expression of specific genes in murine tissues, and to relate these changes to fibrin deposition/dissolution using immunohistochemical approaches. Endotoxin caused large increases in plasminogen activator inhibitor-1 mRNA and modest increases in tissue factor mRNA in most tissues examined. However, fibrin was only detected in the kidneys and adrenals of endotoxin-treated mice, and it was transient. Unexpectedly, changes in urokinase-type plasminogen activator mRNA but not tissue-type plasminogen activator mRNA correlated with fibrin deposition/dissolution in these tissues. Pretreatment of mice with the fibrinolytic inhibitor epsilon-aminocaproic acid before endotoxin increased both the number of fibrin-positive tissues and the duration of fibrin deposition in the kidneys and adrenals. These results suggest that the absence of fibrin in some tissues reflects ongoing local fibrinolysis, and that increases in plasminogen activator inhibitory and tissue fac- tor gene expression and decreases in urokinase-type plasminogen activator expression are necessary for tissue-specific fibrin deposition. Changes in tissue-type plasminogen activator gene expression do not appear to be essential for fibrin deposition/dissolution in this murine model of sepsis.

Adrenal Glands↗
PubMed1982

Comprehensive kinetics of thyroxine distribution and metabolism in blood and tissue pools of the rat from only six blood samples: dominance of large, slowly exchanging tissue pools.

We have estimated 24 physiological parameters of production, interpool transport, distribution, and metabolism of T4 in the major T4 pools of the unanesthetized male Sprague-Dawley rat from six optimally timed blood samples (at 1, 5, 23, 115, 465, 1440 min) and a comprehensive model and analysis. Despite 10-fold lower concentrations of T4 reported in tissues that exchange T4 with plasma at a slow rate (e.g. skeletal muscle) compared with rapidly exchanging tissues like liver and kidney, the composite of slow tissue pools contains 57% of total body T4, with only 17% in fast pools and 26% in plasma. At least 14% of the 0.53 ng/min/100 g BW of T4 secreted is converted to T3 in slow tissue pools, and 24% is an upper bound on whole body T4 to T3 conversion. The T4 fractional turnover rates in fast and slow tissue pools (0.154 and 0.007 min-1), corresponding tissue to plasma T4 fractional transport rates (0.152 and 0.006 min-1), and relative fluxes of T4 from plasma to fast vs. slow tissues (88% vs. 12%) were all found to be approximately the same as those we have reported for T3. As a consequence, the ratio of the fractional (or clearance) rate of entry of T3 into tissue to that of T4 was found to be equal to the ratio of the plasma equivalent distribution volume of T3 to that of T4 in the tissue, which also is the ratio of relative pool sizes of T3 and T4 in the tissue to those in plasma. This ratio (approximately 11) is approximately the same for all tissues, slow and fast, and it is also the same as the ratio of the net binding of T3 and T4 to plasma proteins. Finally, despite a 10 times slower early disappearance rate for a bolus of T4 than for T3 and reported single half-lives for T4 3-6 times greater, T4 actually spends only a third longer time (17.5 h) in the whole system, mostly in slow pools, before ultimate irreversible disposal.

Animals↗
PubMed2003

[Expression of connective tissue growth factor gene in the hypertrophic scar and keloid tissue].

OBJECTIVE: To explore the effect of connective tissue growth factor on the pathogenesis of hypertrophic scar and keloid tissue. METHODS: The content of hydroxyproline was determined and the expression of connective tissue growth factor gene was detected by the reverse transcription-polymerase chain reaction and image analysis technique in 5 normal skins, 15 hypertrophic scars and 7 keloid tissues. RESULTS: The contents of hydroxyproline in the hypertrophic scar (84.10 +/- 1.76) and keloid tissue (92.38 +/- 2.04) were significantly higher than that of normal skin tissue (26.52 +/- 4.10) (P < 0.01). The index of connective tissue growth factor mRNA in the hypertrophic scar (0.78 +/- 0.63) and keloid tissue (0.84 +/- 0.04) were higher than that of normal skin tissue (0.09 +/- 0.25) (P < 0.01). CONCLUSION: Connective tissue growth factor may play an important role in promoting the fibrotic process of hypertrophic scar and keloid tissue.

Adolescent↗
PubMed2004

Molecular and morphometric description of adipose tissue during weight changes: a quantitative tool for assessment of tissue texture.

The aim of this study was to evaluate the morphometric changes of adipose tissue of lean and obese rats as assessed by computerized image analysis (IA) system in experimental conditions, with different degrees of adiposity. Moreover, to validate measures obtained by image analysis by correlation with direct measures of adiposity (body weight, epididimal fat, mean fat cell size and serum leptin). Finally to correlate these changes to expression of genes involved in lipid deposition and mobilization in adipose tissue. Lean (Fa/?) and genetically obese (fa/fa) Zucker rats were studied. Obese rats were food-restricted or treated with retinoic acid (ATRA) in order to reduce body weight and fat content. Moreover, gene expression of two key enzymes involved in fat metabolism (HSL and DGAT) were assessed in adipose tissue by RT-PCR. Our results show that HSL expression in adipose tissue was lower in obese compared to lean rats (1.47+/-0.02 vs 0.35+/-0.03, p<0.005) and was upregulated during food restriction in obese rats. DGAT expression was similar in lean and obese rats and was reduced by treatment with ATRA in obese rats. Tissue texture assessed by IA was significantly higher in lean compared to obese rats (23.2+/-0.6 vs 11.6+/-2.4%; p=0.01). Tissue structure highly correlated with adiposity in obese rats with different amount of body fat (area fraction vs epididimal fat depot: p=0.001). Distribution of measures for each sample, an index of spread of adipose tissue texture, as expressed by the standard deviation, correlated with adiposity (standard deviation vs epididimal fat depot: p=0.002) thus suggesting that adipose tissue texture increases its heterogeneity when adiposity is lower. This observation is in agreement with the hypothesis that the process of lipid mobilization from adipose tissue is not uniform, but a subpopulation of slimming adipocytes undergoes a complete release of their fat content while the rest of the tissue is much less affected. Moreover, image analysis system seems a reliable quantitative tool for assessment of adipose tissue texture.

Adipose Tissue↗
PubMed1997

Plasma tissue factor antigen levels in capillary whole blood and venous blood: effect of tissue factor on prothrombin time.

To measure the amount of tissue factor released during specimen collection and its potential effect of shortening the prothrombin time, we measured tissue factor and prothrombin time in twenty-three paired venous and capillary blood samples from anticoagulated patients and in ten paired samples from controls. We also compared venous prothrombin time determined by a plasma-based assay with venous and capillary prothrombin time determined with a whole blood assay. Venous specimens were obtained using a two-syringe technique; capillary specimens were obtained by fingerstick after wiping the first drop of blood. Plasma tissue factor was determined by an enzyme-linked immunoabsorbant assay. The patients' mean venous tissue factor (235 +/- 101 pg/ml) and capillary tissue factor (268 +/- 106 pg/ml) were higher than those of the controls (161 +/- 42 pg/ml and 187 +/- 63 pg/ml, respectively, P < 0.05). These differences disappeared after adjusting for age. Capillary tissue factor levels were higher than venous tissue factor (244 +/- 102 pg/ml vs. 213 +/- 93 pg/ml), with a mean difference of 31 pg/ml (P = 0.0001). In addition, whole blood prothrombin time was lower in the capillary than in the venous samples (17.7 +/- 5 sec vs. 18.3 +/- 5.4 sec, P = 0.004). However, there was no correlation between capillary-venous differences in tissue factor and capillary-venous differences in the whole blood prothrombin time. Whole blood capillary and venous prothrombin times highly correlated with the plasma-based venous prothrombin time (r = 0.98, P < 0.0001). These results demonstrate that obtaining blood by fingerstick does not result in a clinically significant release of tissue factor. In addition, we did not observe any interference of plasma tissue factor with the whole blood prothrombin time assay. A direct relationship between tissue factor and age was observed.

Adult↗
PubMed2004

Can the apparent diffusion coefficient be used as a noninvasive parameter to distinguish tumor tissue from peritumoral tissue in cerebral gliomas?

PURPOSE: To determine whether the apparent diffusion coefficient (ADC) can be used to distinguish between tumor tissue and peritumoral brain tissue in cerebral gliomas. MATERIALS AND METHODS: Twenty-two patients with 44 biopsies were enrolled in this study. ADC maps calculated from a diffusion-weighted (DW) multislice EPI sequence were coregistered with conventional MR images. Neuronavigated biopsies and intraoperative markers were used for correlation with the histologic specimens. ADC values and lesion-to-brain ratios of the different sequences were calculated and compared for tumor tissue and peritumoral brain tissue. A logistic regression analysis was performed to determine the diagnostic value of the ADC maps. RESULTS: The ADC values and ratios demonstrated a large overlap between tumor tissue and peritumoral tissue. Group comparisons revealed a significantly (P=0.03) lower ADC ratio in tumor tissue (mean=1.28 +/- 0.39) compared to peritumoral tissue (mean=1.48 +/- 0.30), whereas the absolute ADC values did not differ significantly. In the logistic regression analysis, the lesion-to-brain ratio of the gadolinium (Gd)-enhanced T1-weighted sequence was the most valuable predictor of the presence of tumor tissue. The ADC value and ratio were not identified as significant predictors. CONCLUSION: The ADC is not helpful for distinguishing tumor tissue from peritumoral brain tissue in gliomas.

Adolescent↗
PubMed2005

Focal brain ischemia in rat: acute changes in brain tissue T1 reflect acute increase in brain tissue water content.

Several recent studies have reported changes of brain tissue T(1) in ischemic models during the first minutes after occlusion of the middle cerebral artery (MCA). In order to assess whether these tissue T(1) changes are related to an increase in tissue water content, we performed T(1) (7 T) and tissue water content measurements in a rat model (n = 10, Sprague-Dawley) of focal cerebral ischemia (intraluminal occlusion model). The tissue water content was determined using a gravimetric technique. The animals were divided into two groups: an ischemic group, with an effective MCA occlusion (n = 6) and a control group, with animals having undergone sham surgery but no MCA occlusion (n = 4). In the ipsilateral cortex, the tissue water content was 81.1 +/- 0.7% at 2 h 15 min following ischemic insult (contralateral value: 79.3 +/- 0.5%). Concomitantly, the tissue T(1) in the ipsilateral cortex was 2062 +/- 60 ms at ischemia onset + 1 h (contralateral 1811 +/- 28 ms) and 2100 +/- 38 ms at ischemia onset + 2 h (contralateral 1807 +/- 18 ms). The tissue T(1) and tissue water content values measured in the contralateral area do not differ from the values obtained in the control group. A significant T(1) increase is observed at ischemia onset + 1 h (+ 14%) and ischemia onset (+ 2 h) + 16%, together with a significant increase in tissue water content (+ 2.3%). This suggests that there is an increase in tissue water content concomitant with cell swelling during the first hours of ischemia.

Animals↗
PubMed2006

Expression of resistin protein in normal human subcutaneous adipose tissue and pregnant women subcutaneous adipose tissue and placenta.

The expression of resistin protein in normal human abdominal, thigh, pregnant women abdominal, non-pregnant women abdominal subcutaneous adipose tissue and placenta and the relationship between obesity, type 2 diabetes mellitus (T2DM), pregnant physiological insulin resistance (IR) and gestational diabetes mellitus (GDM) was investigated. The expression of resistin protein in normal human abdominal, thigh, pregnant women abdominal, non-pregnant women abdominal subcutaneous adipose tissue and placenta was detected by using Western blotting method. Fasting serum glucose concentration was measured by glucose oxidase assay. Serum cholesterol (CHOL), serum triglycerides (TG), serum HDL cholesterol (HDL-C) and serum LDL cholesterol (LDL-C) were determined by full automatic biochemical instrument. Fasting insulin was measured by enzyme immunoassay to calculate insulin resistance index (IRI). Height, weight, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured to calculate body mass index (BMI) and body fat percentage (BF %). Resistin protein expression in pregnant women placental tissue (67 905 +/- 8441) (arbitrary A values) was much higher than that in subcutaneous adipose tissue in pregnant women abdomen (40 718 +/- 3818, P < 0.01), non-pregnant women abdomen (38 288 +/- 2084, P < 0.01), normal human abdomen (39 421 +/- 6087, P < 0.01) and thigh (14 942 +/- 6706, P < 0.001) respectively. The resistin expression in abdominal subcutaneous adipose tissue showed no significant difference among pregnant, non-pregnant women and normal human, but much higher than that in thigh subcutaneous adipose tissue (P < 0.001). Pearson analysis revealed that resistin protein was correlated with BMI (r = 0.42), fasting insulin concentration (r = 0.38), IRI (r = 0.34), BF % (r = 0.43) and fasting glucose (r = 0.39), but not with blood pressure, CHOL, TG, HDL-C and LDL-C. It was suggested that resistin protein expression in human abdominal subcutaneous adipose tissue was much higher than that in human thigh subcutaneous adipose tissue. Resistin was closely related with central obesity, leading to IR, subsequently obesity and T2DM. Resistin protein expression in placental tissue was much higher than that in subcutaneous adipose tissue in normal human abdomen, pregnant abdomen, non-pregnant women abdomen and thigh. It was indicated that resistin protein could be secreted from human placental tissue. Resistin might be one of the factors that lead to pregnant physiological IR and GDM.

Blood Glucose↗
PubMed1998

Tissue engineering: generation of differentiated artificial tissues for biomedical applications.

A new field in biomedical science has been established. Cell biologists, engineers, and surgeons now work within a team. Artificial connective, epithelial, or neuronal tissues are being constructed using living cells and different kinds of biomaterials. Numerous companies and laboratories are presenting dynamic developments in this field. Prognoses predict that, at the beginning of the coming century, the industry of tissue engineering will reach the importance of the present genetic technology. An enormous demand for organ and tissue transplants motivates research activities and drives the acquisition of innovative techniques and creative solutions. At the front of this development is the creation of artificial skin for severely burned patients and the generation of artificial cartilage for implantation in articular joint diseases. Future challenges are the construction of liver organoids and the development of an artificial kidney on the basis of cultured cells. In this paper we show strategies, needs, tools, and equipment for tissue engineering. The presupposition for all projects is the induction, development, and maintenance of differentiation within the tissue under in vitro conditions. As experiments in conventional culture dishes continued to fail, new cell and tissue culture methods had to be developed. Tissues are cultured under conditions as close as possible to their natural environment. To optimize adherence or embedding, cells are grown on novel tissue carriers and on individually selected biomatrices or scaffolds. The tissues are subsequently transferred into different types of containers for permanent perfusion with fresh culture medium. This guarantees constant nutrition of the developing tissue and prevents the accumulation of harmful metabolites. An organo-typical environment for epithelial cells, for example, is obtained in gradient containers, which are permanently superfused at the apical and basal sides with different media. Long term experiments result in cultured tissues in a quality thus far unreached.

Biomedical Engineering↗
PubMed2006

Prostate tissue stiffness as measured with a resonance sensor system: a study on silicone and human prostate tissue in vitro.

Prostate cancer is the most common form of cancer in men in Europe and in the USA. Some prostate tumours are stiffer than the surrounding normal tissue, and it could therefore be of interest to measure prostate tissue stiffness. Resonance sensor technology based on piezoelectric resonance detects variations in tissue stiffness due to a change in the resonance frequency. An impression-controlled resonance sensor system was used to detect stiffness in silicone rubber and in human prostate tissue in vitro using two parameters, both combinations of frequency change and force. Variations in silicone rubber stiffness due to the mixing ratio of the two components could be detected (p<0.05) using both parameters. Measurements on prostate tissue showed that there existed a statistically significant (MANOVA test, p<0.001) reproducible difference between tumour tissue (n=13) and normal healthy tissue (n=98) when studying a multivariate parameter set. Both the tumour tissue and normal tissue groups had variations within them, which were assumed to be related to differences in tissue composition. Other sources of error could be uneven surfaces and different levels of dehydration for the prostates. Our results indicated that the resonance sensor could be used to detect stiffness variations in silicone and in human prostate tissue in vitro. This is promising for the development of a future diagnostic tool for prostate cancer.

Acoustics↗
PubMed1998

Resistance factors in colon cancer tissue and the adjacent normal colon tissue: glutathione S-transferases alpha and pi, glutathione and aldehyde dehydrogenase.

Glutathione S-transferases (GST) alpha and pi, glutathione (GSH) and aldehyde dehydrogenase (ADH) were determined in colorectal cancer tissue specimens and in the adjacent normal colon tissue. The median contents in normal and cancer tissue were 8.1 (2.3-30.3) (5-95% quantiles) and 15.1 (5.3-50.3) microg/mg protein for GST pi (P = 0.035), 0.0 (0.0-1.4) and 0.4 (0.0-3.5) microg/mg protein for GST alpha (P = 0.019), 7.3 (1.3-22.7) and 5.6 (2.3-26.0) microg/mg protein for GSH (P = 0.171) and 30.8 (13.0-42.0) and 23.2 (9.0-32.9) microg/mg protein for ADH (P = 0.0017), respectively. Thus, the mean GST alpha and pi both significantly increased in colon cancer compared to the adjacent normal tissue, which underlines their importance as possible resistance factors. A highly significant correlation was obtained between the GSH content in colon cancer and normal tissue (P = 0.0017). Thus, the constitutive GSH expression seems to be maintained during tumor development. A similar correlation was obtained for ADH (P = 0.0075), but the median ADH was lower in cancer tissue compared to the adjacent normal tissue (P = 0.0017). Contrary to GSH and ADH, GST pi did not correlate between normal and colon cancer tissue. Whereas GSH and ADH correlated in normal colon tissue (P = 0.014), no significant correlation for GSH and ADH was observed in colon cancer tissue (P = 0.109). In conclusion, significant correlations between colon cancer and normal tissue were obtained, suggesting that the expression levels of these resistance factors are maintained during carcinogenesis in most patients.

Aldehyde Dehydrogenase↗
PubMed2000

Fetal tissue banking for transplantation: characteristics of the donor population and considerations for donor and tissue screening.

We initiated this study to evaluate the suitability for therapeutic use in transplantation of tissues obtained from human abortuses. We have developed protocols for the collection, handling and preservation of hepatic stem cells from electively aborted embryos and have developed methods for assessment of the cells so derived and processed. In this paper we present our findings regarding screening of potential donors, acquisition of fetal tissues, and assessment of the tissues for potentially infectious contaminants. We assess the suitability of the tissue donors according to current standards used for donors of commonly transplanted tissues (e.g., bone grafts, skin grafts and heart valves) and present data regarding the real availability of tissues from elective abortion procedures that would meet those standard tissue banking criteria.We specifically evaluated the donor's willingness to provide a blood sample for testing, conducted a detailed interview similar to those used for typical organ and tissue donors, and assessed the type and incidence of contamination in collected tissues. We find that although many women are willing to consent to use of the tissues for transplantation, attrition from the study for various reasons results in few fetal organs ultimately realistically available for transplantation. Typical reasons for attrition include: unwillingness to have a blood sample drawn or tested, positive serology results, social/medical high risk factors for acquisition of transmissible disease, no identifiable organs available, and unacceptable microbial contamination. Thus, although it might seem that due to the numbers of abortions performed annually, that there would be substantial numbers of suitable tissues available, only a small proportion are truly suitable for transplantation.

Journal Article↗