Hot and not-so-hot females: reproductive state and thermal preferences of female Arizona Bark Scorpions (Centruroides sculpturatus).

For ectotherms, environmental temperatures influence numerous life history characteristics, and the body temperatures (Tb ) selected by individuals can affect offspring fitness and parental survival. Reproductive trade-offs may therefore ensue for gravid females, because temperatures conducive to embryonic development may compromise females' body condition. We tested whether reproduction influenced thermoregulation in female Arizona Bark Scorpions (Centruroides sculpturatus). We predicted that gravid females select higher Tb and thermoregulate more precisely than nonreproductive females. Gravid C. sculpturatus gain body mass throughout gestation, which exposes larger portions of their pleural membrane, possibly increasing their rates of transcuticular water loss in arid environments. Accordingly, we tested whether gravid C. sculpturatus lose water faster than nonreproductive females. We determined the preferred Tb of female scorpions in a thermal gradient and measured water loss rates using flow-through respirometry. Gravid females preferred significantly higher Tb than nonreproductive females, suggesting that gravid C. sculpturatus alter their thermoregulatory behaviour to promote offspring fitness. However, all scorpions thermoregulated with equal precision, perhaps because arid conditions create selective pressure on all females to thermoregulate effectively. Gravid females lost water faster than nonreproductive animals, indicating that greater exposure of the pleural membrane during gestation enhances the desiccation risk of reproductive females. Our findings suggest that gravid C. sculpturatus experience a trade-off, whereby selection of higher Tb and increased mass during gestation increase females' susceptibility to water loss, and thus their mortality risk. Elucidating the mechanisms that influence thermal preferences may reveal how reproductive trade-offs shape the life history of ectotherms in arid environments.

Metallothionein induction and deinduction in human prostatic carcinoma cells: relationship with resistance and sensitivity to adriamycin.

Human prostate carcinoma cell line DU-145 was used to examine the relationship between the intracellular levels of cysteine-rich metallothionein (MT) and the sensitivity or resistance of cells to Adriamycin (ADR). The basis for the poor response of human prostate carcinomas to ADR was studied. Cadmium-resistant (Cdr) cells, capable of growth in 10(-5) M cadmium, were derived from DU-145 cadmium-sensitive (Cds) cells, by exposure to increasing concentrations of cadmium. The relative rates of MT synthesis were measured by L-[35S]cysteine incorporation and MT separation by high-performance liquid chromatography. Cdr cells, continuously exposed to cadmium, show a steady-state rate of MT synthesis (designated as control = 100%) which is 3.5 times the basal rate in Cds cells (29%). Dose-response curves, using clonal and cell count assays, show that the dose levels required to produce inhibition of growth to 50% and 90% of control, respectively, of ADR for Cdr cells (19.00 and 132.0 ng/ml) are 1.5 to 1.7 times those for Cds cells (12.5 and 77.5 ng/ml). In the absence of cadmium, deinduction of MT occurs with MT synthesis declining, after 70 and 118 h, to 29% and 19% of control. Correspondingly, in such deinduced cells (Cdr minus cadmium), the 50% inhibitory doses of ADR in clonal and growth assays are 3.5 and 4.8 ng/ml, respectively. Thus, deinduced cells are 3 and 4 times more sensitive to ADR than Cds and Cdr cells. This increased sensitivity is explained by the rapid and marked inhibition of MT synthesis upon exposure to ADR, even in the presence of cadmium, so that after 6 and 10 h in the presence of 10 ng/ml of ADR, the rates drop to 62% and 19% of control. On the basis of these results, we propose that: (a) the increased levels of MT increase the resistance of Cdr cells to ADR and that this may be partly responsible for the poor response of prostate carcinomas to ADR; (b) MT deinduction results in increased sensitivity to ADR; and (c) ADR inhibits MT synthesis. Thus, it is suggested that a treatment regimen consisting of ADR exposure followed by a second exposure, during increased ADR sensitivity, may be effective for growth inhibition of slow-growing prostatic carcinomas.

Ornithine as a possible marker of cancer.

The nonprotein amino acid ornithine is the major source of polyamines in mammalian physiological systems. Increased urinary polyamine levels have been demonstrated in humans with varied types of cancers. The metabolism of DL-[1-14C]ornithine monohydrochloride in rats with either Walker 256 carcinoma or chemically induced methylcholanthrene tumors was studied. Following the i.p. injection of 3 muCi[14C]ornithine per 100 g body weight, the decarboxylation of ornithine-yielding 14CO2 was monitored by utilizing the vibrating reed electrometer-ionization chamber model of Davidson and Schwabe. Tumor-bearing animals showed significant increases in ornithine metabolism as compared to controls; for Walker 256 the tumor-bearing animal to control ratio rose from 1.16 to 1.78, for methylcholanthrene implants it rose from 1.19 to 1.82, and for methylcholanthrene paintings it rose from 1.00 to 2.20. With tumor regression ornithine levels of metabolism in the tumor-bearing animals returned to base line or nearly base-line levels. These results encourage us in our attempt to develop ornithine as a biological marker of cancer.

Cadmium-induced malignant transformation of human prostate epithelial cells.

Prostate cancer has become epidemic, and environmental factors such as cadmium may be partly responsible. This study reports malignant transformation of the nontumorigenic human prostatic epithelial cell line RWPE-1 by in vitro cadmium exposure. The cadmium-transformed cells exhibited a loss of contact inhibition in vitro and rapidly formed highly invasive and occasionally metastatic adenocarcinomas upon inoculation into mice. The transformed cells also showed increased secretion of MMP-2 and MMP-9, a phenomenon observed in human prostate tumors and linked to aggressive behavior. Cadmium-induced malignant transformation of human prostate epithelial cells strongly fortifies the evidence for a potential role of cadmium in prostate cancer.

Malignant transformation of human prostate epithelial cells by N-nitroso-N-methylurea.

We report the malignant transformation of adult human prostate epithelial cells after multiple exposures to the chemical carcinogen N-nitroso-N-methylurea. Such transformants showed morphological alterations and anchorage-independent growth in soft agar and induced carcinomas when transplanted into nude mice. No p53 or ras mutations were observed. Stepwise chromosomal changes in the progression to tumorigenicity were observed. Loss of the p arms of chromosome 8 (p10>pter) and chromosome 10 (p10>pter) and gain of the q arm of chromosome 8 (q10>qter) were only observed in the tumor outgrows. These findings provide the first evidence of malignant transformation of human prostate epithelial cells exposed to a chemical carcinogen.

Retinoic acid modulates extracellular urokinase-type plasminogen activator activity in DU-145 human prostatic carcinoma cells.

Effects of all-trans retinoic acid (RA) on the net enzymatic activity of secreted, extracellular urokinase-type plasminogen activator (u-PA) in DU-145 human prostatic carcinoma cells were examined to assess the potential use of retinoids in human prostate cancer prevention and treatment. u-PA is associated with tumor progression involving invasion and metastasis. Based on a chromogenic substrate assay, results show that DU-145 cells secrete five times more u-PA than normal human prostatic epithelium. DU-145 cells were treated with 0.1 to 10 micrometer RA for 48 h. This short treatment of cells with RA did not inhibit growth. After a 48-h treatment of cultures with RA, serum-free conditioned medium was analyzed for u-PA activity by SDS-PAGE zymography. Two major bands of u-PA with Mr of approximately 54,000 (high molecular weight u-PA) and approximately 33,000 (low molecular weight u-PA) were detected. Plasminogen-dependent catalytic activity of these bands could be specifically inhibited with antibody to u-PA, confirming that these bands represent u-PA. A 48-h treatment with 1.0 micrometer RA reduced u-PA activity in conditioned medium to 51.6% of control. A 50% reduction in free u-PA antigen level, as compared to control, was further demonstrated at 1.0 micrometer RA by Western blot analysis and densitometry. These results show that RA can decrease the net extracellular urokinase activity produced by prostatic carcinoma cells. It is proposed that these effects of RA may have important implications not only in the chemoprevention of prostate cancer, by inhibition of promotion of prostatic intraepithelial neoplasia to invasive carcinoma, but also in tumor progression during invasion and metastasis, by decreasing extracellular matrix degradation, as shown in our accompanying article (M. M. Webber and A. Waghray, Clin. Cancer Res., 1: 755-761, 1995).

Urokinase-mediated extracellular matrix degradation by human prostatic carcinoma cells and its inhibition by retinoic acid.

Both normal and malignant prostatic epithelial cells in culture secrete urokinase-type plasminogen activator (u-PA) into the culture medium. u-PA has been shown to have a direct association with invasive and metastatic potential of many types of cancers. We propose that prostate cancer has the intrinsic ability to invade and metastasize because of its inherent ability to secrete the serine protease u-PA. We further propose that in prostate cancer, u-PA is the key enzyme which occupies a place at the apex of the proteolytic cascade and initiates the degradative process. Subsequently, collagenases are recruited after activation of procolla-genases by another serine protease plasmin formed by the activation of plasminogen by u-PA. Extracellular proteolysis involving plasmin can cause massive degradation of the extracellular matrix. We show that u-PA alone can use fibronectin as a substrate and degrade it, but u-PA alone did not degrade laminin. Serum-free conditioned medium from DU-145 human prostatic carcinoma cells has the ability to degrade both fibronectin and laminin. However, treatment of cultures with 1 microM all-trans retinoic acid (RA) for 48 h reduced the ability of serum-free conditioned medium to cause u-PA-mediated degradation of fibronectin and laminin. Thus, RA had a protective effect on these extracellular matrix glycoproteins. Treatment of cells with RA also decreased their ability to invade Matrigel in the in vitro invasion assay in a dose-dependent manner. RA at the 0.5, 1, and 10 microM level reduced invasion to 65.7%, 46.7%, and 34.3% of control, respectively. RA reduced extracellular proteolysis and thus inhibited extracellular matrix degradation and invasion. These results may also explain one mechanism by which retinoids inhibit invasion and metastasis in vitro and in vivo. These studies have important translational value in the chemoprevention of progression of prostatic intraepithelial neoplasia to invasive carcinoma.

Prostate-specific antigen, a serine protease, facilitates human prostate cancer cell invasion.

Human prostatic epithelial cells constitutively secrete prostate-specific antigen (PSA), a kallikrein-like serine protease, which is a normal component of the seminal plasma. PSA is currently used as a specific diagnostic marker for the early detection of prostate cancer. We demonstrate that PSA degrades extracellular matrix glycoproteins fibronectin and laminin and, thus, may facilitate invasion by prostate cancer cells. Blocking PSA proteolytic activity with PSA-specific mAb results in a dose-dependent decrease in vitro in the invasion of the reconstituted basement membrane Matrigel by LNCaP human prostate carcinoma cells which secrete high levels of PSA. A novel PSA-SDS-PAGE zymography method for the detection of matrix degrading ability of PSA is also described. We propose that: (a) because of the dysplastic cellular disorganization in early neoplastic lesions called prostatic intraepithelial neoplasia (PIN), PSA may be secreted not only at the luminal end but also, abnormally, at the cell-basement membrane interface, causing matrix degradation and facilitating invasion; and (b) PSA, along with urokinase, another serine protease secreted by prostatic epithelium, may be involved in the proteolytic cascade during prostate cancer invasion and metastasis. The discovery of the extracellular matrix degrading ability of PSA not only makes it a marker for early detection but also a target for prevention and intervention in prostate cancer.

ras Activation of human prostate epithelial cells induces overexpression of parathyroid hormone-related peptide.

Immortalized adult and fetal prostate cell lines grown in serum-free conditions produce low levels of parathyroid hormone-related peptide (PTHRP) in the presence of growth factors as assessed by mRNA analysis, PTHRP immunoreactivity, and immunohistochemistry. Subsequent infection of these cells with Kirsten murine sarcoma virus containing an activated Ki-ras oncogene induces at least a 10-20-fold increase in PTHRP expression and production of both adult and fetal immortalized cell lines in the presence of the same growth factors. These results provide the first evidence of direct activation of PTHRP by the ras oncogene in human prostate cells and suggest its potential usefulness as a tumor marker in prostate malignancies.

Modulation of the malignant phenotype of human prostate cancer cells by N-(4-hydroxyphenyl)retinamide (4-HPR).

A long latent period of 20 to 30 years may be involved in the multistep process of carcinogenesis represented by prostatic intraepithelial neoplasia (PIN) in the prostate. It is, therefore, possible that progression to a malignant state could be blocked or reversed during this time. Retinoids not only have the ability to block steps in the process of carcinogenesis but they may also modulate or reverse some malignant characteristics of cancer cells. This study focuses on the ability of N-(4-hydroxyphenyl)-retinamide (4-HPR), a synthetic retinoid, to reverse malignant characteristics towards a normal phenotype, using the human prostate carcinoma cell line DU-145. These malignant characteristics include abnormal cell proliferation, intermediate filament expression, motility, invasion, and cell survival. Results show that 1 microM and 10 microM 4-HPR caused 31% and 96% inhibition of growth, while all-trains retinoic acid (ATRA) produced similar effects at 10 and 100 microM, making 4-HPR ten times more effective than ATRA. While DU-145 cells show strong immunostaining for vimentin, treatment with 1 microM 4-HPR for eight days caused a marked decrease in vimentin staining. This was accompanied by a change from an elongated to an epithelial cell morphology. Densitometric analysis of Western blots for vimentin showed a 53% decrease in vimentin expression in 1 microM 4-HPR treated cells. Concomitant with the decrease in vimentin expression, cell motility and invasive ability also decreased by 32% and 52%, respectively. Growth inhibition was accompanied by DNA fragmentation and apoptosis. Exposure of cells to 1 microM 4-HPR caused a marked upregulation of nuclear retinoid receptors RARalpha and a detectable expression of RARgamma. These results suggest that inhibition of growth and vimentin expression, and induction of apoptosis by 4-HPR in prostate cancer cells may occur via a receptor-mediated mechanism involving transrepression of AP-1 by retinoid receptors. We propose that vimentin may serve as a useful intermediate marker for early detection of prostate cancer in biopsy specimens and that 4-HPR may be effective in blocking several steps in prostate carcinogenesis as well as the progression of PIN to invasive carcinoma.

Ornithine metabolism in normal subjects and patients with cancer.

The metabolism of L-(1-14C)ornithine monohydrochloride was monitored in patients with histologically proven cancer and in normal volunteers. Following i.v. injection of 8 microCi C-14 ornithine (160 nmoles), the decarboxylation of ornithine--yielding 14CO2--was monitored for a 2.5-hr period using the ionization chamber and vibrating-reed electrometer of Tolbert, as modified by Davidson and Schwabe. Twelve normal subjects exhaled 7.3-15.7% of the administered C-14 (mean 12.6% s.d. 3.11%). In ten patients tested before initiation of therapy, recovery ranged from 18.2-32.1% (mean 23.02%, s.d. 4.52%). A t-test indicates a confidence level of > 99.5% that a significant difference exists between the two means. Re-testing of two normal volunteers showed little or no change in ornithine metabolism over a 2-5-mo period. Results from testing three cancer patients before and after therapy correlate well with clinical evidence of the presence of tumor burden.

Effects of 'crack' cocaine on pulmonary alveolar permeability.

BACKGROUND: Lung clearance of 99mTc-labeled diethylenetriamine pentaacetate (DTPA) is a sensitive test of altered alveolar epithelial permeability that has been found to be increased in smokers of tobacco, as well as a small number of healthy smokers of crack cocaine, suggesting the possibility of subclinical crack-related lung injury. STUDY OBJECTIVE: To evaluate further whether habitual smoking of cocaine alone alters alveolar permeability, whether crack smoking adds to or potentiates the effects of tobacco and/or marijuana, and whether experimental cocaine smoking acutely alters DTPA lung clearance. DESIGN: Observational cohort study (habitual cocaine smoking) and single-blind crossover study (experimental cocaine administration). SUBJECTS: Fourteen habitual smokers of cocaine alone (CS), 19 smokers of cocaine and tobacco (CTS), 3 smokers of cocaine and marijuana, 12 smokers of cocaine, tobacco, and marijuana (CMTS), and 5 smokers of marijuana plus tobacco (MTS). Results obtained in the crack-smoking subjects were compared with data previously obtained in 10 nonsmokers (NS), 9 smokers of tobacco alone (TS), 10 smokers of marijuana alone (MS), and 4 additional MTS. METHODS: Subjects underwent measurements of DTPA radioaerosol lung clearance after refraining from marijuana and/or cocaine for > 12 h and from tobacco for >2 h. Ten of the 48 crack users were tested on two days 1 to 2 weeks apart within 2 h of experimental smoking of three physiologically active or inactive doses (total 98.8+/-15.5 or 8.5+/-2.5 mg, respectively) of cocaine base. Lung clearance half-times (T1/2) were computed from time-activity curves for each lung. RESULTS: T1/2 values for each lung in CS and MS were comparable to those of NS, while TS, MTS, CTS, and CMTS had significantly shorter clearance rates than NS (p<0.01; three-way analysis of variance). No additive or interactive effects on T1/2 were noted among tobacco, cocaine, and/or marijuana. No acute effect of experimental cocaine smoking on T1/2 was noted. CONCLUSION: Whereas regular smoking of tobacco alone or with other substances increases alveolar epithelial permeability, habitual smoking of cocaine and/or marijuana has no measurable effect on alveolar permeability in the absence of tobacco nor any additive effect to that of tobacco alone.

Radioisotope detection of venous thrombosis. Venous scan vs fibrinogen uptake test.

Experience with the fibrinogen uptake test and the technetium Tc 99m albumin aggregated venous scan in 89 patients showed the latter to be adequate for simultaneous screening for plumonary embolism and venous thrombosis of the lower extremities and pelvis. Because the fibrinogen uptake test differentiated active from inactive venous thrombosis, it is indicated when anticoagulation is considered for patients with a history of thrombophlebitis and equivocal clinical findings of acute activity. It can also be used to monitor high-risk patients and to detect proximal propagation of thrombi. The results of the technetium venous scan were abnormal in 97% of patients with venous thrombosis and the fibrinogen uptake test detected 100% of patients with acute activity. Both tests react to different aspects of the thrombotic disease, thus complementing each other. Because of their reliability, indications for phlebography are now less frequent.

Inferior vena cava interruption: a new indication?

Propagating illofemoral venous thrombosis that occurs despite adequate anticoagulation can be detected by the serial fibrinogen uptake test. Twenty-three patients who were receiving heparin sodium for confirmed iliofemoral thrombophlebitis underwent the serial fibrinogen uptake test. There was an increasing percentage of isotope uptake at the groin and the upper part of the thigh in eight of these patients, three of whom subsequently developed clinical signs, perfusion, and ventiliation lung scan findings compatible with the occurrence of pulmonary embolism. The remaining 15 patients had decreasing serial fibrinogen uptake during heparin therapy and no sequelas indicative of pulmonary embolism. Progressive thrombosis in adequately heparinized patients indicates failure of anticoagulation therapy and, when this occurs, we believe that interior vena cava interruption should be considered before a first, but potentially lethal, pulmonary embolus develops.

Radionuclide bone imaging.

Radionuclide bone imaging of the skeleton, now well established as the most important diagnostic procedure in detecting bone metastases, is also a reliable method for the evaluation of the progression or regression of metastatic bone disease. The article concentrates on the technetium-99m agents and the value of these agents in the widespread application of low-dose radioisotope scanning in such bone diseases as metastasis, osteomyelitis, trauma, osteonecrosis, and other abnormal skeletal conditions.

Long-term quantitative results following fundoplication and antroplasty for gastroesophageal reflux and delayed gastric emptying in children.

BACKGROUND: The operative management of children with combined gastroesophageal reflux and delayed gastric emptying is controversial. This study measures the long-term follow-up of gastric emptying in children who have undergone gastroesophageal fundoplication combined with antroplasty. METHODS: Fifteen randomly selected children with gastroesophageal reflux and scintigraphically demonstrated delayed gastric emptying underwent fundoplication and antroplasty. Each patient had another gastric emptying scintigraphic study performed an average of 3.6 years postoperation. RESULTS: All patients reported improvement of their symptoms compared with before the operation, and none required further medical therapy for gastroesophageal reflux or experienced dumping syndrome. Eleven of the 15 patients had significant long-term improvement of their gastric emptying postoperatively. The mean percent of isotope meal remaining in the stomach at 90 minutes improved from 72% preoperatively to 40% postoperatively (P = 0.0005). CONCLUSIONS: Gastric emptying in children with gastroesophageal reflux and delayed gastric emptying is significantly improved for several years in three-fourths of patients after fundoplication and antroplasty. Fundoplication and concomitant antroplasty are recommended for symptomatic children with documented gastroesophageal reflux and delayed gastric emptying.

The role of alpha 6 beta 1 integrin and EGF in normal and malignant acinar morphogenesis of human prostatic epithelial cells.

Complex multiple interactions between cells and extracellular matrix occur during acinar morphogenesis involving integrin receptors and growth factors. Changes in these interactions occur during carcinogenesis as cells progress from a normal to a malignant, invasive phenotype. We have developed human prostatic epithelial cell lines of the same lineage, which represent multiple steps in carcinogenesis, similar to prostatic intraepithelial neoplasia and subsequent tumor progression. The non-tumorigenic, RWPE-1 and the tumorigenic WPE1-NB27 and WPE1-NB26 cell lines were used to examine their ability to undergo acinar morphogenesis in a 3-D cell culture model and its relationship to invasion, integrin expression and EGF presence. An inverse relationship between the degree of acinar formation and invasive ability was observed. The non-tumorigenic, non-invasive RWPE-1 and the low tumorigenic, low invasive, WPE1-NB27 cells show high and decreased acinar forming ability, respectively, while the more invasive WPE1-NB26 cells show a loss of acinar formation. While RWPE-1 acini show basal expression of alpha 6 beta 1 integrin, which correlates with their ability to polarize and form acini, WPE1-NB27 cells lack alpha 6 but show basal, but weaker expression of beta 1 integrin. WPE1-NB26 cells show loss alpha 6 and abnormal, diffused beta 1 integrin expression. A dose-dependent decrease in acinar formation was observed in RWPE-1 cells when cell proliferation was induced by EGF. Anti-functional antibody to EGF caused an increase in acinar formation in RWPE-1 cells. These results suggest that malignant cells lose the ability to undergo acinar morphogenesis and that the degree of this loss appears to be related to invasive ability, EGF levels and alterations in laminin-specific integrin expression. This model system mimics different steps in prostate carcinogenesis and has applications in the secondary and tertiary prevention of prostate cancer.

Evaluation of the chemopreventive potential of retinoids using a novel in vitro human prostate carcinogenesis model.

The prevalence of prostatic intraepithelial neoplasia (PIN) and latent prostatic carcinoma, representing multiple steps in carcinogenesis and progression to invasive carcinoma, makes them relevant targets for prevention. A unique family of human prostate epithelial cell lines, which mimic steps in prostate carcinogenesis and progression, were used to evaluate the chemopreventive potential of all-trans-retinoic acid (RA) and N-(4-hydroxyphenyl)retinamide (4-HPR). The effects of RA and 4-HPR on anchorage-dependent growth of an immortalized, non-tumorigenic cell line RWPE-1 and two tumorigenic cell lines, WPE1-NB14 and WPE1-NB11, derived from RWPE-1 by exposure to N-methyl-N-nitrosourea (MNU), were examined. Both tumorigenic cell lines grow more rapidly than the parent RWPE-1 cell line in monolayer culture. Further, while RWPE-1 cells do not form colonies in agar, both tumorigenic cell lines do, with a colony forming efficiency (CFE) of 1.85 and 2.04% for WPE1-NB14 and WPE1-NB11 cells, respectively. Both RA and 4-HPR inhibited anchorage-dependent growth of all cell lines and anchorage-independent growth of WPE1-NB14 and WPE1-NB11 cells, in a dose-dependent manner, however, 10 times more RA than 4-HPR was required to produce the same effect. RWPE-1 cells are not invasive but WPE1-NB11 cells are significantly more invasive than WPE1-NB14 cells. Both RA and 4-HPR inhibited invasion in vitro by WPE1-NB11 and WPE1-NB14 cells where the more malignant WPE1-NB11 cells showed greater inhibition of invasion by 4-HPR than by RA. Overall, 4-HPR was more effective than RA in inhibiting growth and invasion but the response varied amongst the cell lines. These three cell lines mimic progressive steps in carcinogenesis and progression, from immortalized, non-tumorigenic RWPE-1 cells, to the less malignant WPE1-NB14 to the more malignant WPE1-NB11 cells, and provide powerful models for studies on secondary and tertiary prevention, i.e. promotion and progression stages, respectively, of prostate cancer.

N-(4-hydroxyphenyl)retinamide (4-HPR) decreases neoplastic properties of human prostate cells: an agent for prevention.

The development of prostate cancer through a multistep process of carcinogenesis may have a long latent period of 20-30 years. It is possible that progression to a malignant state could be blocked or reversed during this time. This study focuses on the ability of the synthetic retinoid, N-(4-hydroxyphenyl)-retinamide (4-HPR), to reverse changes associated with malignant transformation and tumor progression, towards a normal phenotype. To examine the responsiveness of cells at different steps of prostate carcinogenesis, three immortalized, but non-tumorigenic (RWPE-1, WPE1-7 and WPE1-10), and one human prostate carcinoma cell line (DU-145), were used. The effects of 4-HPR on cell proliferation, expression of intermediate filament proteins cytokeratin 18 and vimentin, and tumor suppressor proteins p53 and pRb were examined by immunostaining and compared. Results show that 4-HPR caused inhibition of growth in all cell lines in a dose-dependent manner. 4-HPR induced an increase in staining for cytokeratin 18, a marker of differentiation for prostate epithelial cells. While all cell lines showed strong immunostaining for vimentin, treatment with 4-HPR for 8 days caused a marked decrease in staining for vimentin in all cell lines. In an in vitro assay, 4-HPR also caused inhibition of invasion by DU-145 cells in a dose-dependent manner. Furthermore, 4-HPR treatment was effective in significantly decreasing the abnormal nuclear staining for the tumor suppressor proteins p53 and pRb. Because 4-HPR decreased invasion-associated vimentin expression, inhibited invasion, and normalized p53 and pRb immunostaining, we propose that 4-HPR may be an effective agent for secondary and tertiary prevention, i.e. promotion and progression stages, respectively, of prostate cancer.

Fibrinogen uptake test. Criteria for interpretation of results in patients with venous thrombosis.

Accurate detection of active deep venous thrombosis with the fibrinogen uptake test (FUT) requires adherence to rigid criteria for interpretation of results of the tests. In a series of 56 patients, only detection of serial increase of per cent uptake at the same position correlated with presence of active venous thrombosis in all cases. Other investigated criteria, which were based on the analysis of single FUT results, showed a 21% incidence of false positive results. Accordingly, active venous thrombosis investigation by FUT requires performance of serial tests and analysis of the curve of uptake at each position to detect serial increasing per cent uptake.