Prostate cancer bone metastases acquire resistance to androgen deprivation via WNT5A-mediated BMP-6 induction.

BACKGROUND: Androgen ablation is the first-line therapy for patients with metastatic prostate cancer (CaP). However, castration resistance will eventually emerge. In the present study, we have investigated the role of bone morphogenetic protein-6 (BMP-6) in the development of castration-resistant prostate cancer (CRPC) in the context of bone metastases. METHODS: We initially investigated the clinical course of 158 men with advanced CaP who were treated with primary androgen deprivation therapy. To elucidate the underlying mechanism of CRPC in the context of bone metastases, we examined the impact of bone stromal cells on CaP in the absence of androgens using a co-culture model. RESULTS: In the 158 patients, we found that the median time to prostate-specific antigen progression was significantly shorter when bone metastases were present (14 months (95% CI, 10.2-17.8 months) vs 57 months (95% CI, 19.4-94.6 months)). These results suggest that bone-tumour interactions may accelerate castration resistance. Consistent with this hypothesis, in vitro co-cultures demonstrated that CaP cells proliferated under an androgen-depleted condition when incubated with bone stromal cells. Mechanistically, gene expression analysis using quantitative polymerase chain reaction arrays showed a dramatic induction of BMP-6 by CaP cell lines in the presence of bone stromal cells. Further studies revealed that WNT5A derived from bone stromal cells induced the expression of BMP-6 by CaP cells; BMP-6 in turn stimulated cellular proliferation of CaP cells in an androgen-deprived media via a physical interaction between Smad5 and ß-catenin. Intracellularly, WNT5A increased BMP-6 expression via protein kinase C/NF-κB pathway in CaP cell lines. CONCLUSIONS: These observations suggest that bone-CaP interaction leads to castration resistance via WNT5A/BMP-6 loop.

Fluctuations in the production of specific cellular peptides during the growth of animal cells.

Patterns of newly synthesized proteins of Vero cells in different growth states were obtained using two-dimensional gel electrophoresis. The 240 most prevalent peptide spots were then compared. Cells in exponential growth and in the stationary phase were found to have patterns of peptide spots characteristic of their state of growth. The transition between these patterns is progressive, and the cells acquire a pattern characteristic of quiescent cells by the late exponential phase. These observations suggest that a series of modulations in gene expression occurs during the transition of growth states in animal cells that leads to the specific appearance or disappearance of certain cellular peptides.

Growth-related fluctuation in messenger RNA utilization in animal cells.

Monkey fibroblasts maintained in culture regulate their levels of intracellular protein throughout the growth cycle by means of variations in the rate of protein biosynthesis. Cytoplasmic mRNA in stationary phase cells was compared to that in exponential phase cells. In stationary phase cells 56% of the cytoplasmic polyadenylated RNA was found in the 40--90S postpolysomal region of sucrose sedimentation gradients, while only 23% was found in this region in exponential phase cells. Analysis of electron micrographs of sectioned exponential and stationary phase cells revealed that this shift in polyadenylated RNA location is accompanied by a loss of polysome-like aggregates of ribosomes. Most if not all of this species of postpolysomal polyadenylated RNA is not being translated by single ribosomes since no detectable amounts of nascent peptide were present in this region. This nonpolysomal polyadenylated RNA is comparable in size to polysomal polyadenylated RNA. The length of the 3'-poly(A) tract was also comparable for these two species. The extent of capping of poly(A)-containing molecules was also comparable for these two species. The template activity of nonpolysomal RNA in a wheat germ extract was comparable to that of polysomal RNA. The peptides produced by these two preparations were of a similar large size. Furthermore, most of the nonpolysomal polyadenylated RNA of stationary phase cells was driven into polysomes in the presence of a low dose of cycloheximide. Therefore, we conclude that the untranslated mRNA that accumulates in stationary phase cells is structurally intact, is fully capable of being translated, and is not being translated due to the operation of a translational initiation block.

Effects of triethyl phosphate and nitrate on electrokinetically enhanced biodegradation of diesel in low permeability soils.

Bench-scale experiments for electrokinetically enhanced bioremediation of diesel in low permeability soils were conducted. An electrokinetic reactor (ER) was filled with kaolin that was artificially contaminated with diesel at a level of 2500 mg kg(-1). A constant voltage gradient of 1.0 V cm(-1) was applied. In phosphorus transport experiments, KH2PO4 was not distributed homogeneously along the ER, and most of the transported phosphorus was converted to water-insoluble aluminum phosphate after 12 days of electrokinetic (EK) operation. However, the advancing P front of triethyl phosphate (TEP) progressed with time and resulted in uniform P distribution. The treatments employed in the electrokinetically enhanced bioremediation of diesel were control (no addition of nitrogen and phosphorus), NP (KNO3+ KH2PO4), NT (KNO3+ TEP), UP (urea+ KH2PO4), and UT (urea+TEP). Analysis of effluent collected during the first 12 days of EK operation showed that diesel was not removed from the kaolin. After nutrient delivery, using the EK operation, the ER was transferred into an incubator for the biodegradation process. After 60 days of biodegradation, the concentrations of diesel in the kaolin for the NP, NT, UP, UT, and control treatments were 1356, 1002, 1658, 1612, and 2003 mg kg(-1), respectively. The ratio of biodegraded diesel concentration to initial concentration (2465 mg kg(-1)) in NP, NT, UP, UT, and control were 45.0%, 59.4%, 32.7%, 34.6%, and 18.7%, respectively. This result showed that TEP, treated along with NO3-, was most effective for the biodegradation of diesel. TEP was delivered more efficiently to the target zones and with less phosphorus loss than KH2PO4. However, this facilitated phosphorus delivery was effective in biodegrading diesel under anaerobic conditions only when electron acceptors, such as NO3-, were present.

Remineralization of artificial caries-like lesions in human enamel in situ by chewing sorbitol gum.

The objective of the study was to determine quantitatively the effect on the potential for in situ remineralization of artificial caries-like lesions in human enamel when sugar-free gum containing mainly sorbitol as sweetener was chewed after meals and snacks. Artificial white-spot lesions were created in extracted human premolars and divided into three parts. One part was used as reference and the other two worn consecutively for two 21-day periods by 10 volunteers in a cast silver band cemented on lower molar teeth and covered with gauze to promote plaque formation. During the experimental periods, the subjects used fluoridated toothpaste twice daily, and consumed three meals (breakfast, lunch, and dinner) and two snacks (selected from chocolate bar, raisins, chocolate wafer, and iced cupcake). Sorbitol gum was chewed for 20 min immediately after each meal or snack during one of the experimental periods. The three parts of the enamel lesions were then sectioned (congruent to 80 microns) and examined together by means of quantitative microradiography and by polarized light microscopy. All estimates of mineral content indicated that significant remineralization occurred and was approximately doubled with gum-chewing. It is suggested that sorbitol gum stimulates salivation, which is responsible for the significantly enhanced remineralization, thus contributing to a therapeutic, caries-preventive effect. Because the gum was chewed immediately after meals and snacks, inhibition of demineralization may also have occurred.

Changes in the myelinated axons of femoral nerve in amyotrophic lateral sclerosis.

Myelinated fibres in femoral nerves removed from amyotrophic lateral sclerosis (ALS) cases at post mortem were compared with age matched controls. A technique for processing whole transverse sections of the nerves for osmication and subsequent morphometric analysis is described. Although areas depleted in myelinated fibres were seen in the nerves from the ALS group, no statistically significant difference was shown due to wide variations in the controls. However, the ALS nerves showed a degree of disruption in the myelin which was not apparent in the controls. The most obvious effect was widespread "wrinkling" of the myelin in both large and small fibres from the ALS nerves. This phenomenon is the initial stage of a process which eventually results in uneven myelin thickness and nodal swellings and finally myelin ovoids and balls. We illustrate the steps in the progression of this degeneration with teased nerve studies and electron microscopy and propose that there are qualitative changes in the myelin of peripheral nerve in ALS. It seems likely that these are secondary effects resulting from axonal degeneration caused by deterioration and loss of anterior horn cells in the spinal cord.

(AC)(n) polymorphism of aldose reductase gene and diabetic microvascular complications in type 2 diabetes mellitus.

Recent studies suggest that the gene encoding aldose reductase, the enzyme that converts glucose to sorbitol, may confer susceptibility to microvascular disease. The aim of this study therefore, was to investigate the relationship between the aldose reductase gene and type 2 diabetic microvascular complications such as diabetic nephropathy and retinopathy. DNA from 127 Korean patients with type 2 diabetes was typed for an (AC)(n) dinucleotide repeat polymorphic marker at the 5'-end of the aldose reductase gene using polymerase chain reaction. No significant difference in the frequency of the putative risk allele Z-2 was found in patients of nephropathy and retinopathy groups compared with the uncomplicated group (32.2, 34.1 vs. 25.1%, respectively, P>0.05). Similarly, no difference was found in the frequency of the putative protective allele Z+2 among any of the study groups. In conclusion, the results of the study in Korean type 2 diabetic patients do not support the hypothesis that polymorphism at the 5' end of the aldose reductase gene contributes to the susceptibility to diabetic microvascular complications.

Occlusal variation in Chinese immigrants to the United Kingdom and their offspring.

Occlusal variations of immigrant Chinese parents, raised in less developed areas, were compared with their children who were born and bred in the United Kingdom. Of 11 occlusal traits, nine were significantly more variable or less well developed in the offspring. Because genetic factors were unchanged, the deterioration in occlusion in the offspring indicates environmental influences such as dietary consistency, premature deciduous tooth loss from caries and oral respiration.

The influence of a two-day recruiting course on groups of fifth and sixth formers.

The fall in applications to dental schools in the UK has resulted in various recruiting strategies. One such move was the introduction of a two-day residential course for fifth and sixth formers which was first instigated in 1989. This paper describes the course which had been run on four occasions with a total of 160 participants. The results of a survey on the impressions of the course by these participants is reported. It appears that the courses are effective in increasing interest in dentistry in the vast majority of participants.

Needs for dental information of adolescents from an inner city area of Liverpool.

The aim of this study was to determine the needs for dental information of adolescents and investigate the relationship of their desire for information with their opinion of who decides to make an appointment with the dentist (ie parent or child). In-depth interviews were conducted with 10 adolescents (aged 14 to 16 years) to derive questions for a questionnaire to assess dental information needs. One hundred and fifty-eight adolescents of similar age attending a secondary school in Liverpool were invited to complete the questionnaire. The results showed that adolescents are interested in finding out more information on different aspects of dental health which included especially: how to keep their teeth for life, about the best toothpaste, what to do in case they sustain dental injury and whether they required an orthodontic appliance. Another important finding was that more than half of the adolescents (57%) felt that they were responsible for taking decisions for their dental attendance. These children expressed a desire to know more about certain dental matters. Information needs of young people are important because of evidence derived from this study suggesting that acquisitiveness for dental information in this group, has possible implications for future patterns of seeking dental care.

Preliminary validation and reliability of the Modified Child Dental Anxiety Scale.

An 8-question Modified Child Dental Anxiety Scale was developed to assess children's concerns about specific dental procedures. These dental situations include examination, scale and polish, injection, filling, extraction, and relative and general anaesthesia. A question about how the child felt generally when visiting the dentist was also included. Children (n = 314) from two schools in Liverpool, ages 8 to 15 years, completed a questionnaire including the modified scale, Corah's Dental Anxiety Scale, the Dental Fear Survey Schedule for Children, and background questions (age, sex and previous dental experience). The internal consistency was favourable (alpha = .84) and test-retest reliability acceptable. This initial study suggests that the scale may be useful in trials to assess the benefits of interventions to assist children receive dental treatment.

Childhood leukemia and dental considerations.

Leukemia is the major form of cancer in children in Britain and mirrors the percentage of children affected in the USA. This report outlines some of the medical aspects of leukemia and its treatment and gives a guide to the dentist, who may have the responsibility of dealing with leukemic children and their families.

Increased trophoblast expression of NFAT5/TonEBP in pre-eclamptic placentas and hyperosmolar-treated BeWo cells.

OBJECTIVES: To assess the concentrations of inositol and sorbitol, and determine the expression of related osmolyte factors [nuclear factor of activated T cells 5, also known as tonicity responsive binding protein (NFAT5/TonEBP); sodium myo-inositol transporter (SLC5A3); and aldose reductase] in placentas of pre-eclamptic (PE) patients and trophoblast BeWo cells subjected to hypertonic stress in vitro. STUDY DESIGN: Control and PE placentas were collected. BeWo cells were cultured and subjected to a hyperosmolar solution for 4h. Western blot analysis was performed on NFAT5, SLC5A3, aldose reductase and ERK proteins. High-performance liquid chromatography was used to determine the levels of inositol and sorbitol in cell lysates. RESULTS: Compared with control placentas, PE placentas showed higher levels of inositol and NFAT5, and lower levels of SLC5A3. Treated BeWo cells showed higher levels of inositol, sorbitol, NFAT5 total protein, SLC5A3 and aldose reductase, and increased ERK activation compared with control BeWo cells. CONCLUSIONS: Hyperosmolar conditions increase the expression of NFAT5 in PE placentas and BeWo cells, and may account for the increased osmolyte levels. NFAT5 may accomplish this through aldose reductase and SLC5A3 in trophoblast cells.

The use of general anaesthesia for the extraction of children's teeth. Results from two UK dental hospitals.

AIM: To study the reasons forgiving children a general anaesthetic (GA) for the extraction of teeth, in two different paediatric dentistry centres and to compare them with draft guidelines disseminated for discussion by the British Society of Paediatric Dentistry (BSPD). METHODS: Data were collected on children who required GA extractions over a two month period (1st may to 30th June 2004) at the Paediatric Dental Units of Liverpool University Dental Hospital (LUDH) and the University Dental Hospital of Manchester (UDHM). The information collected included date of birth, gender, date of referral, date of assessment and date of GA. The reason for the GA was noted in terms of the proposed BSPD guidelines for short GA. RESULTS: A total of 264 and 268 children required extractions under GA at LUDH and UDHM respectively. At LUDH the main reason in 189 (72%) children was severe pulpitis requiring immediate relief of pain where a child does not have the intellectual maturity to cope with treatment under local analgesia (LA). This was followed by failed extractions under LA in 53 (20%) children. This reason is not listed under the proposed BSPD guidelines. At UDHM the main reason for GA in 114 (42%) children was symptomatic teeth causing pain in more than two quadrants (or in two quadrants necessitating the use of bilateral inferior dental blocks). CONCLUSIONS: There were differences in the clinical rationale for GA between children attending the two centres. Further information is needed to refine the proposed guidelines on the use of GA for dental extractions in paediatric dentistry. The guidelines need to be flexible and updated to reflect changes in practice and service provision.

The frequency of repeat general anaesthesia for teeth extractions in children.

AIM: The purpose of this study was to determine the frequency of repeat extractions under general anaesthesia (GA) in children. METHODS: The dental hospital records of patients attending for outpatient GA extractions at Liverpool University Dental Hospital, Liverpool, UK, between January and March 2003 were examined retrospectively. A data collection form was used to record the relevant information. RESULTS: A total of 278 patients with a mean age of 6.5 years (SD = 2.2 years) were seen for GA extractions. Of those, 33 patients (11.9%) with a mean age of 4.9 years (SD = 2 years) at the time of their initial GA had had a previous or would undergo a subsequent episode of GA extraction. The mean interval between repeat GA was 2.3 years (SD = 1.6 years). Fifteen cases (45.5%) had the repeat GA within 2 years. Radiographs were available as part of the assessment process for 84 (34.3%) of the 245 patients who had had a single episode of GA. However, of the 33 patients who had had a repeat GA, only seven (21.2%) had radiographs available at the time of the initial GA. Regarding the number of teeth extracted, a significant difference (P < 0.01) was found between the number of teeth extracted in patients who had had a single GA (mean = 4.6, SD = 2.5), compared with those extracted at the initial GA for the repeat GA group (mean = 3.2, SD = 2). CONCLUSION: The frequency of repeat GA is relatively low, but there is a need for appropriate treatment planning incorporating the use of radiographs to reduce this even further.