Search PubMed⌕ Search

Biomedical subjects

A Bergh

Publications and source records attributed to A Bergh.

At least 55 records · Page 3Linked to original sources

Application of the 5'-nuclease PCR assay in evaluation and development of methods for quantitative detection of Campylobacter jejuni.

Campylobacter jejuni is recognized as a leading human food-borne pathogen. Traditional diagnostic testing for C. jejuni is not reliable due to special growth requirements and the possibility that this bacterium can enter a viable but nonculturable state. Nucleic acid-based tests have emerged as a useful alternative to traditional enrichment testing. In this article, we present a 5'-nuclease PCR assay for quantitative detection of C. jejuni and describe its evaluation. A probe including positions 381121 to 381206 of the published C. jejuni strain NCTC 11168 genome sequence was identified. When this probe was applied, the assay was positive for all of the isolates of C. jejuni tested (32 isolates, including the type strain) and negative for all other Campylobacter spp. (11 species tested) and several other bacteria (41 species tested). The total assay could be completed in 3 h with a detection limit of approximately 1 CFU. Quantification was linear over at least 6 log units. Quantitative detection methods are important for both research purposes and further development of C. jejuni detection methods. In this study, we used the assay to investigate to what extent the PCR signals generated by heat-killed bacteria interfere with the detection of viable C. jejuni after exposure at elevated temperatures for up to 5 days. An approach to the reduction of the PCR signal generated by dead bacteria was also investigated by employing externally added DNases to selectively inactivate free DNA and exposed DNA in heat-killed bacteria. The results indicated relatively good discrimination between exposed DNA from dead C. jejuni and protected DNA in living bacteria.

Campylobacter Infections↗

Cigarette smoke and hypoxia induce acute changes in the testicular and cerebral microcirculation.

The acute effects of cigarette smoking and hypoxia on the cerebral and testicular microcirculation were studied in anestethised adult rats. Smoking for 2 min did not influence arterial pO2, pCO2 or pH but it induced an increase in cerebral blood flow by 34% and inhibited vasomotion in the testis for about 1 h. One hour after smoke exposure apnea induced a slight increase in arterial pCO2, a significant decrease in pO2, and an increase in cerebral blood flow (CBF) by 54%. In animals not previously exposed to cigarette smoke apnea increased CBF by 121%, demonstrating that a short-term exposure to tobacco smoke influences the cerebrovascular reactivity for more than one hour. In the testis, apnea resulted in a decreased blood flow by 39% and a complete depression of vasomotion. Breathing 10% O2/90% N2 resulted in moderate hypoxia, a total disappearance of the vasomotion in the testis, a 24% decrease in testicular blood flow, but a 23% increase in CBF.

Animals↗

Tumor associated macrophages in human prostate cancer: relation to clinicopathological variables and survival.

Tumor associated macrophages (TAM) influence diverse processes such as angiogenesis, tumor cell proliferation, and metastasis during tumor progression. In a variety of tumor types, the amount of TAM has been associated with prognosis, but their role in prostate cancer has not been elucidated. The purpose of this study was to investigate the role of TAM in a series of 85 cases of prostatic carcinoma, diagnosed at transurethral resection of the prostate between 1975-1983, using immunohistochemistry and morphometrical techniques. Macrophage density was assessed as the maximum number of TAM per field in the three most macrophage dense areas (TAMmax) and as the average volume density of TAM in an estimate of the whole resected tumor. Furthermore, the individual cell profile area of TAM was assessed with an image analyzer. Macrophage variables were thereafter related to histological grade, tumor stage, metastasis as well as to vascular density, tumor cell proliferation and survival. Patients with a volume density of TAM in the fourth quartile had a shorter median cancer specific survival time than patients in the first to third quartile (3.3 vs. 5.9 years, p=0.005). Furthermore, an increased macrophage cell profile area was related to poor clinical outcome (4.6 vs. 5.9 years, p=0.039) whereas TAMmax gave no prognostic information. In a multivariate analysis, metastasis and the volume density of macrophages gave independent prognostic information (p=0.0008, p=0.010). However, when excluding metastasis from the analysis, only Gleason score was an independent predictor of cancer specific survival (p= 0.005). The volume density of TAM, the macrophage cell profile area and TAMmax increased with increasing Gleason score (p=0.001, p=0.0001, p=0.0001 respectively). A correlation was found between the volume density of TAM and tumor cell proliferation (rs=0.44, p=0.001) and an increased macrophage cell profile area was associated to microvessel density (rs=0.42, p=0.0001). Together these results suggest that both the functional state (as reflected by cell size), number and location of the macrophages are of importance for their influence on prostate tumors, but macrophage quantification is not a strong independent prognostic factor.

Adenocarcinoma↗

Fractionated radiotherapy of rat prostatic adenocarcinoma (Dunning R3327-PAP) in nonanesthetized animals.

BACKGROUND: The dose-response effect of fractionated external beam radiotherapy on nonanesthetized rats bearing the androgen-sensitive prostatic adenocarcinoma Dunning R3327-PAP was studied. METHODS: The radiation was given with a photon beam from a 4-MeV linear accelerator in doses from 4 to 11 Gray per fraction during 5 consecutive days. When the tumors with low and intermediate radiation doses relapsed into regrowth, the rats were castrated. Tumor volumes and rat weights were followed, and at the end of the study a morphometric analysis of the tumors was done. RESULTS: Fractionated irradiation induced a dose-dependent delay in tumor growth in hormonally intact rats. Castration stopped the tumor regrowth, showing that some of the tumor cells were still hormone-sensitive. The study was facilitated by the nonanesthesia procedure. CONCLUSIONS: The Dunning R3327-PAP hormone-sensitive rat tumor is sensitive to radiotherapy in a dose-dependent way. Regrowing, irradiated tumors contain hormone-sensitive cells. This work provided basic knowledge for further experimental studies of the effects of radiation on prostatic adenocarcinoma.

Adenocarcinoma↗

Early castration-induced upregulation of transforming growth factor beta1 and its receptors is associated with tumor cell apoptosis and a major decline in serum prostate-specific antigen in prostate cancer patients.

BACKGROUND: The mechanism behind castration-induced apoptosis in prostate cells is unknown, but data from other species suggest that transforming growth factor beta1 (TGF-beta1) may be involved. METHODS: By using quantitative RT-PCR and immunohistochemistry, expression of TGF-beta1 and its receptors type I and II (RI and RII) was studied in normal and tumor areas of core biopsies taken before and 2-11 days after castration therapy. The TGF-beta responses were related to changes in apoptotic index and to changes in serum prostate-specific antigen (PSA). RESULTS: In normal prostate tissue, apoptosis was generally increased by castration, and apoptosis was accompanied by an increase in TGF-beta1 and RII mRNA levels (P < 0.05). In tumors, apoptosis was seen only in 44% of the cases and in these, but not in the others, TGF-beta1, RI, and RII mRNA levels were increased (P < 0.05). In the patients showing a prognostically favorable PSA response (nadir PSA <5 ng/ml), but not in the others, RI and RII mRNA levels were significantly upregulated (P < 0.05). CONCLUSIONS: Short-term upregulation of TGF-beta1 and its receptors is associated with apoptosis in human prostate and prostate cancer, and possibly with a favorable clinical outcome after castration therapy.

Apoptosis↗

Expression of gonadotropin-releasing hormone receptor mRNA in the rat ventral prostate and dunning R3327 PAP adenocarcinoma before and after castration.

BACKGROUND: Continuous administration of gonadotropin-releasing hormone (GnRH) agonists in prostate cancer patients results in involution of the tumors due to suppression of androgen production. In addition to the effect of GnRH at the hypothalamic-pituitary level, experiments in vitro on breast, ovary, and prostatic cells have shown an inhibition of cell proliferation, indicating the presence of local GnRH receptors (GnRH-R). The aim of the present study was to investigate the expression of GnRH-R mRNA in the normal rat ventral prostate (VP) and Dunning R3327 PAP adenocarcinoma and to evaluate the effects of castration on receptor mRNA expression. METHODS: RNA was prepared from ovaries, pituitaries, VP, and Dunning tumors from both intact and castrated animals. GnRH-R mRNA levels were quantified by a competitive reverse transcription-polymerase chain reaction (RT-PCR) method. RESULTS: GnRH-R mRNA was detected in normal VP and Dunning tumors. Normal VP showed lower amounts of GnRH-R mRNA compared to Dunning tumors. An elevation of mRNA expression was observed 7 days after castration in Dunning tumors. CONCLUSIONS: GnRH-R mRNA was found in both VP and Dunning tumors, indicating the presence of a local GnRH system. Normal VP showed lower amounts of GnRH-R mRNA when compared to malignant tissues. GnRH-R mRNA levels were elevated in Dunning tumors following castration.

Adenocarcinoma↗

A catheter tactile sensor for measuring hardness of soft tissue: measurement in a silicone model and in an in vitro human prostate model.

Tissue hardness is related to tissue composition, and this is often changed by disease. It is therefore of interest to measure the hardness in an objective and non-invasive way. A tactile sensor based on a vibrating piezoelectric ceramic element in a feedback loop is described. When the sensor touches an object it produces a frequency shift related to the hardness of the object. The aim of this study was to develop an in vitro hardness measurement method using a catheter type version of the sensor. The method was evaluated in an established silicone tissue model and on human prostate tissue in vitro. A linear relationship was found with a high degree of explanation (R2 = 0.98) between a cone penetration hardness standard (DIN ISO 2137) applied to the silicone model and the corresponding frequency shift. The results from measurements on a human prostate tissue sample, fixed with formalin, showed that the relative hardness measured with the tactile sensor correlated (R = -0.96, p < 0.001, N = 60) with the proposed hardness related to the histological composition of the prostate tissue. The results indicated that hardness of prostate tissue, and maybe hardness of human tissue in general, can be expressed according to the cone penetration standard and that the hardness can be measured with this tactile sensory system. These findings hold the promise of further development of a non-invasive tool for hardness measurement in a clinical situation.

Aged↗

Transient ischemia induces apoptosis in the ventral prostate of the rat.

The mechanisms involved in the castration-induced involution of the ventral prostate (VP) are not fully understood. It was recently reported that castration decreases blood flow in the VP in rats and that this occurs before the apoptotic involution of the organ. However, it is unknown whether a decrease in blood flow may trigger apoptosis in the VP, and this was therefore examined in this study. The right iliac artery was clamped for 1 h in adult male rats. After 24 h of reperfusion, the VPs were frozen or fixed. In situ end-labeling (ISEL) was used to identify apoptotic cells, and testosterone repressed prostatic message-2 (TRPM-2) was measured. Proliferating cell nuclear antigen (PCNA) immunohistochemistry was used to identify proliferating cells. Clamping the right iliac artery reduced blood flow in the right VP to 0.17 of that in the contralateral lobe. This relative ischemia resulted in a threefold increase in the volume density of apoptotic epithelial cells on the treated side, but left cell proliferation unaffected. Testosterone substitution did not change this pattern. This study suggests that a transient period of relative ischemia may induce apoptosis in the rat ventral prostate. This may be of importance for the understanding of castration-induced prostatic involution.

Animals↗

Alterations of transforming growth factor beta1 (TGF-beta1) and TGFbeta receptor expressions with progression in Dunning rat prostatic adenocarcinoma sublines.

Transforming growth factor-beta1 (TGF-beta1) inhibits epithelial cell proliferation in the normal prostate. Prostate tumours express high levels of TGF-beta1, and seem to acquire resistance to its anti-proliferative effects with tumour progression. In this study, TGFbeta variations with tumour progression were examined in the Dunning prostatic adenocarcinoma model. Expression of TGF-beta1 and TGFbeta receptor type I and type II (TGFbeta-RI and TGFbeta-RII) in rat dorsolateral prostate (DLP) and Dunning tumour sublines (PAP, AT-1, AT-2, AT-3 and MatLyLu) was examined in vitro and in vivo, using competitive reverse transcription-polymerase chain reaction (RT-PCR), Northern and Western blot, and immunohistochemistry. All tumours expressed elevated levels of TGF-beta1 and TGFbeta-RI mRNA, when compared with the DLP (P < or = 0.05). All tumours except MatLyLu also expressed elevated levels of TGFbeta-RII mRNA (P < or = 0.05). Interestingly, TGFbeta-RII protein levels were very low in the highly metastatic AT-3 and MatLyLu tumours in vivo, when compared with levels in the PAP, AT-1, and AT-2 tumours. This difference was not detected for the AT-1, AT-2, and AT-3 cells in vitro. Immunostaining of TGF-beta1, TGFbeta-RI, and TGFbeta-RII was localised principally in normal and tumour epithelial cells, and occasionally in smooth muscle cells. In conclusion, high expression of TGF-beta1 and TGFbeta-RI and low expression of TGFbeta-RII may contribute to tumour progression and metastasis in the Dunning prostatic adenocarcinoma model.

Activin Receptors, Type I↗

After radiotherapy testosterone stimulation is unable to increase growth in the dunning R3327-PAP prostate tumour.

A study was carried out to investigate whether testosterone treatment is able to influence tumour growth in a rat prostatic adenocarcinoma previously treated with castration and high-dose fractionated irradiation. Copenhagen x Fisher rats bearing the androgen-sensitive, well-differentiated Dunning R3327-PAP tumour were castrated and thereafter treated with external beam radiation with photons from a 4-MV linear accelerator. One month after irradiation, substitution with subcutaneous testosterone was started. Tumour volumes and rat weights were monitored up to 256 days after castration, and at the end of the study a microscopic analysis of the tumours was performed. Irradiation delayed tumour growth as compared with untreated tumours. Castration delayed tumour growth, but a hormone-refractory relapse to doubled tumour volume was seen within 45 days. If testosterone was added after castration, the tumours grew rapidly. However, testosterone failed to increase tumour growth when given to rats treated with orchiectomy and irradiation. Histological examination showed that the irradiated tumours still contained tumour epithelial cells, but these cells apparently do not respond to testosterone stimulation. The well-differentiated and androgen-sensitive rat prostatic adenocarcinoma did not grow after irradiation despite stimulation with testosterone. This indicates that the malignant cells lose their androgen sensitivity after high-dose irradiation.

Adenocarcinoma↗

Apoptosis and p53 gene expression in male reproductive tissues of cadmium exposed rats.

Reverse transcription (RT) PCR technique was used to investigate the mechanism of apoptosis induced by Cd and the change of its related genes in testes and prostate of rats. Adult male rats were given a single (s.c.) injection of CdCl2 0, 2.5, 5.0, 10 mumol/kg. 48 h and 72 h after administration of Cd, animals were sacrificed. The results indicated that Cd can induce apoptosis in testes via p53-independent pathway. No apoptosis occurred in prostate in any of the Cd-exposed groups. There was a clearly negative relationship in testes between p53 gene expression and Cd exposure and this dose-response relationship was observed both at 48 h and 72 h. There was a very small increase of this gene expression in the dorsolateral lobe of the prostate in Cd exposed groups. The other apoptosis related gene, bcl-x, was not detectable in either control or Cd-exposed group in testes and dorsal prostate. Although the MT-I gene was expressed in testes or dorsal prostate both in control and exposed groups, no overexpression of MT-I gene was found after administration of Cd. The expression of MT-I in the ventral prostate was not detected in the control group, but a weak expression was found after Cd exposure. Since p53 is a tumor suppressor gene which can inhibit tumorigenesis, the consequence of a Cd-induced decrease of p53 in testes may have a relation to the known risk of Cd tumorigenesis in this tissue.

Animals↗

Radioimmunotherapy of DU-145 tumours in nude mice--a pilot study with E4, a novel monoclonal antibody against prostate cancer.

The anti-tumour effect of the 131I-labelled antiprostate monoclonal antibody (MAb) E4 was studied in an experimental model with 41 nude mice, subcutaneously xenografted with a human prostate cancer cell line (DU-145). The mice were divided into four study groups, i.e. one receiving single and another repeated injections of the radiolabelled MAb. A third group was injected with non-labelled MAb, and the fourth served as an untreated control group. The tumour volumes increased similarly in all groups during the 27-day observation period. The tumour tissue was morphologically disintegrated in the group that received repeated radioimmunotherapy (RIT). The tumours from this group contained large fluid-filled cystic parts and demonstrated pronounced cellular and subcellular polymorphism in the remaining viable tumour tissue. The untreated control tumours and single therapy tumours remained solid. The proportion of the total tumour volume that consisted of viable tumour cells, as determined by morphometric techniques, was significantly lower in the 131I-E4-treated groups. The use of 131I-labelled E4 MAb has thus demonstrated a promising therapeutic potential.

Animals↗

In Swedish families with hereditary prostate cancer, linkage to the HPC1 locus on chromosome 1q24-25 is restricted to families with early-onset prostate cancer.

Prostate cancer clusters in some families, and an estimated 5%-10% of all cases are estimated to result from inheritance of prostate cancer-susceptibility genes. We previously reported evidence of linkage to the 1q24-25 region (HPC1) in 91 North American and Swedish families each with multiple cases of prostate cancer (Smith et al. 1996). In the present report we analyze 40 (12 original and 28 newly identified) Swedish families with hereditary prostate cancer (HPC) that, on the basis of 40 markers spanning a 25-cM interval within 1q24-25, have evidence of linkage. In the complete set of families, a maximum two-point LOD score of 1.10 was observed at D1S413 (at a recombination fraction [theta] of.1), with a maximum NPL (nonparametric linkage) Z score of 1.64 at D1S202 (P=.05). The evidence of linkage to this region originated almost exclusively from the subset of 12 early-onset (age <65 years) families, which yielded a maximum LOD score of 2.38 at D1S413 (straight theta=0) and an NPL Z score of 1.95 at D1S422 (P=.03). Estimates from heterogeneity tests suggest that, within Sweden, as many as 50% of early-onset families had evidence of linkage to the HPC1 region. These results are consistent with the hypothesis of linkage to HPC1 in a subset of families with prostate cancer, particularly those with an early age at diagnosis.

Age of Onset↗

Erythrocyte-aggregating relapsing fever spirochete Borrelia crocidurae induces formation of microemboli.

The African relapsing fever spirochete Borrelia crocidurae forms aggregates with erythrocytes, resulting in a delayed immune response. Mice were infected with B. crocidurae and monitored during 50 days after infection. Spirochetes were observed extravascularly at day 2 after infection. Two days later, inflammatory responses, cell death, and tissue damage were evident. The pathologic responses in lungs and kidneys were similar, whereas the symptoms in the brains were delayed, with a less pronounced inflammatory response. Microemboli were found in the blood vessels, possibly a result of the erythrocyte aggregation. The B. crocidurae invasion emerged more rapidly than has been described for Lyme disease-causing Borrelia species. In addition to erythrocyte rosetting, the presence of extravascular B. crocidurae indicates a novel route for these bacteria to propagate and cause damage in the mammalian host. The histopathologic findings in this study may explain the clinical manifestations of human relapsing fever.

Animals↗

Testosterone induces vascular endothelial growth factor synthesis in the ventral prostate in castrated rats.

PURPOSE: Recent studies suggest that the vasculature is important for the control of prostate growth. Castration induces an involution of the prostate gland and its vasculature. Replacement of testosterone stimulates endothelial cell proliferation and normalizes vascular volumes and blood flow several days before organ regrowth. Antiangiogenesis treatment inhibits the growth of prostate tumors. Understanding the regulation of the prostate vasculature may therefore provide important knowledge of the mechanisms responsible for the growth of non-malignant and malignant prostate tissue. Castration induced regression and testosterone stimulated regrowth of the prostatic vasculature have here been used to study the involvement of the angiogenic factor vascular endothelial growth factor (VEGF) and its receptors flt-1 and flk-1/KDR in the regulation of the prostatic vasculature. MATERIALS AND METHODS: VEGF, flt-1, and flk-1/KDR levels were quantified in the rat ventral prostate following castration and testosterone replacement. Methods used were competitive RT-PCR, Western blot and immunohistochemistry. RESULTS: VEGF mRNA and protein levels were significantly decreased by castration and testosterone treatment induced VEGF synthesis in the rat ventral prostate epithelium. Flt-1 and flk-1/KDR receptor levels were unaffected by castration and testosterone treatment. CONCLUSIONS: Castration down regulates VEGF and testosterone induces VEGF synthesis in epithelial cells in the rat ventral prostate.

Animals↗

Transforming growth factor beta1 is associated with angiogenesis, metastasis, and poor clinical outcome in prostate cancer.

BACKGROUND: Prostate tumors express high levels of transforming growth factor-beta1 (TGF-beta1) and seem to acquire resistance to its antiproliferative effects with tumor progression. Moreover, TGF-beta1 could be involved in tumor-promoting processes such as angiogenesis, cell migration, and immunosuppression. METHODS: Immunoreactivity for TGF-beta1 and its receptors type I and type II (TGFbeta-RI and TGFbeta-RII), tumor vascular count, and cell proliferation were studied in 73 cases of prostate cancer, diagnosed between 1975-1983 and followed with surveillance. RESULTS: Patients with tumor overproduction of TGF-beta1 had shorter median cancer-specific survival than patients with normal TGF-beta1 immunoreactivity (5.0 vs. 10 years, P = 0.006). Furthermore, increased TGF-beta1 staining was associated with tumor grade, high vascular counts, and metastasis (P = 0.02, 0.02, and 0.01, respectively). Patients with loss of tumor TGFbeta-RII expression in combination with TGF-beta1 overproduction showed particularly short survival (2.6 vs. 10 years, P = 0.0000), when compared to patients with normal immunoreactivity. CONCLUSIONS: Overproduction of TGF-beta1 and loss of TGFbeta-RII expression are associated with poor clinical outcome in prostate cancer, and TGF-beta1 may promote tumor progression by stimulating angiogenesis and metastasis.

Aged↗

Inhibitory effects of soy and rye diets on the development of Dunning R3327 prostate adenocarcinoma in rats.

METHODS: Dunning R3327 PAP prostate tumors were transplanted in 125 rats, the rats were divided into five groups, and tumor development was examined for 24 weeks during treatment with diets containing 33% of soy flour (SD), rye bran (RB), heat-treated rye bran (HRB), or rye endosperm (RE). RESULTS: In the SD, RB, and HRB groups, significantly fewer palpable tumors and lower tumor volume were detected 14 and 16 weeks after transplantation when compared with the control, fiber-free dietary (FF) group. The body weight was lower 16 weeks after tumor transplantation in the RB and HRB groups when compared with the control group (P < 0.05). Rats in the RB and the HRB groups had a significant lower energy intake than the FF group during the first metabolic observation period, 3-6 weeks after tumor transplantation (P < 0.05), whereas the energy intake was the same in all groups during the second metabolic observation period, 13-16 weeks after tumor transplantation. However, when the tumor volume was adjusted for the body weight of the animals, there were still significant lower tumor volumes in the SD, RB, and HRB groups compared with the FF group (P < 0.05). A significant increase in daily urinary excretion of the isoflavonoids, daidzein, O-desmethylangolensin, equol, and Genistein, was observed in the rats fed SD, and of the ligands enterolactone and enterodiol in the rats fed RB and HRB during both metabolic periods. There were no differences in testosterone levels between the groups. CONCLUSIONS: The present study shows that SD inhibits implanted prostate cancer growth. Although RB and HRB had a protective effect, further studies are needed to exclude the possibility that a low energy intake played a role in this respect. The results suggest that phytoestrogens (isoflavonoids and ligands), may be responsible for the delayed prostate tumor growth.

Adenocarcinoma↗

Expression of vascular endothelial growth factor and its receptors in the rat ventral prostate and Dunning R3327 PAP adenocarcinoma before and after castration.

BACKGROUND: Angiogenesis is important for prostate organogenesis and prostate cancer progression. It is not yet known whether androgens promote part of their control of prostate structure and function by influencing angiogenesis. The aim of this study was to explore the possible androgenic regulation of the angiogenic factor vascular endothelial growth factor (VEGF) and its receptors flt-1 and flk-1/KDR in the rat ventral prostate (VP) and Dunning R3327 PAP adenocarcinoma. METHODS: RNA was prepared from VP and tumors of intact and castrated rats. VEGF, flt-1, and flk-1/KDR mRNA levels were determined using competitive RT-PCR. RESULTS: VEGF121, VEGF165, and VEGF189 together with flt-1 and flk-1/KDR mRNA were detected. The VEGF, but not flt-1 mRNA levels were significantly decreased in the VP after castration. The Dunning tumor expressed high levels of mRNA for VEGF and its receptors compared to the VP. The flt-1 mRNA level in the tumor increased after castration, while the VEGF mRNA levels were unchanged. CONCLUSIONS: Decreased mRNA expression of VEGF, but not flt-1, was found in the rat VP after castration. However, in the Dunning tumor, castration did not alter the expression of VEGF mRNA. Moreover, elevated levels of both mRNA for VEGF and its receptors relative to the VP were observed, indicating that the VEGF system may be important for Dunning tumor development.

Adenocarcinoma↗