Mortality in a cohort of complex patients with chronic illnesses and multimorbidity: a descriptive longitudinal study

Background

Certain advanced chronic conditions (heart failure, chronic lung disease) are associated with high mortality. Nevertheless, most of the time, patients with these conditions are not given the same level of attention or palliative care as those with cancer.

The objective of this study was to assess mortality and its association with other variables in a cohort of complex multimorbid patients with heart failure and/or lung disease from two consecutive telemonitoring studies.

Methods

This multicentre longitudinal study was conducted between 2010 and 2015. We included 83 patients (27 without telemonitoring) with heart failure and/or lung disease with > 1 hospital admission in the previous year and great difficulties leaving home or were housebound. The following variables were indicators of their complex clinical condition: old age (mean: 81 years), comorbidity (Charlson Comorbidity Index score ≥ 2: 86.2 %), both conditions concurrently (54.2 %) and home oxygen therapy (52 %).

We assessed mortality (rate, cause and place of death) and its association with: age, sex, telemonitoring, functional status (Barthel score), quality of life (EQ-5D visual analogue scale), number of medications, and all-cause and condition-specific (due to conditions prompting inclusion) admissions during the previous year. Uni- and bivariate analysis and logistic regression were performed, considering p < 0.05 significant.

Results

A total of 61 patients died within 5 years, representing 31.2 %/year (95 % CI: 23–40.1 %), considering the overall follow-up (sum of individual follow-up days). Of these, 81 % of deaths (95 % CI: 69.1–89–1 %) were due to the condition prompting inclusion, and 83.3 % (95 % CI: 72–90.7 %) died in hospital (median: 8.5 days).

Mortality was lower among those under telemonitoring (p = 0.027), and with fewer condition-specific admissions the previous year (p = 0.006); the latter also showed the strongest association in the multivariate analysis (Exp(B) = 6.115).

Conclusions

Complex patients with multimorbidity had a high mortality rate, generally dying due to the condition for which they had been included, and in hospital (83.3 %). New approaches for managing such patients should be considered, introducing palliative care as required, and using more comprehensive predictors of mortality (functional status and quality of life), together with those related to the illness itself (previous admissions, progression and symptoms).

Variations in the vestibular cortical bone of permanent canine teeth in orthodontic patients. a comparative study: linear tomography vs. cbct (3d accuitomo)

The aim of this study was to compare the results of measuring the height of the vestibular cortical bone of canine teeth by linear tomography (LT) and 3-D Accuitomo cone beam computed tomography (CBCT) before and after aligning dental arches by orthodontic treatment. LT and CBCT were performed before and after orthodontic alignment on 12 canines in three patients undergoing orthodontic treatment, and the height of the canine vestibular cortical bones measured in mm. Measurements were taken by double-blinded operators. The mean variation in height of the vestibular cortical bone with orthodontic treatment was - 0,33 mm} 0.233 standard error using CBCT and -0,08mm } 0.55 standard error using LT. Analysis of variance (ANOVA) was performed to compare the techniques, the patients and upper and lower canines. No significant difference was found for any of the cases. Using LT to evaluate vestibular crest cortical bone in canines is comparable in efficiency to using CBCT. Height in millimeters is less in LT because image resolution is lower and when it is very thin it is not appreciable by this method.

The utility of serologic tests as biomarkers for Helicobacter pylori-associated precancerous lesions and gastric cancer varies between Latin American countries

PURPOSE

Currently, studies on serologic diagnosis of Helicobacter pylori-associated gastric cancer (GC) in Latin America are scarce. The aim of the present study was to evaluate the association between H. pylori serology tests in patients with early precancerous lesions or GC, when compared with non-atrophic gastritis in Colombia, Paraguay, and Mexico, three countries in Latin America with a high prevalence of H. pylori infection but contrasting rates of GC mortality.

METHODS

Gastric biopsies and blood samples were obtained from patients attending the gastroenterology or oncology services of hospitals in the three participating countries. IgG antibodies against H. pylori whole-cell antigens and CagA were tested in 1,117 sera using an enzyme-linked immunoabsorbent assay.

RESULTS

Positive and significant associations were shown for H. pylori seropositivity and preneoplastic lesions in Mexico (OR 2.0; 95 % CI 1.1-3.4) but not in Colombia (OR 1.2; 95 % CI 0.6-2.1) or Paraguay (OR 1.5; 95 % CI 0.6-3.2); no significant associations were shown for GC in any country. CagA seropositivity was associated with preneoplasic lesions in all three countries (ORs = 2.1, 3.0, and 3.1 for Mexico, Colombia, and Paraguay, respectively), and with GC only in Colombia (OR 4.3; 95 % CI 2.1-9.2).

CONCLUSIONS

In countries of Latin America, the IgG CagA test might be a useful biomarker for patients with gastric preneoplastic lesions and for those at risk of developing gastric cancer.

Body mass index in early adulthood and colorectal cancer risk for carriers and non-carriers of germline mutations in DNA mismatch repair genes

BACKGROUND

Carriers of germline mutations in DNA mismatch repair (MMR) genes have a high risk of colorectal cancer (CRC), but the modifiers of this risk are not well established. We estimated an association between body mass index (BMI) in early adulthood and subsequent risk of CRC for carriers and, as a comparison, estimated the association for non-carriers.

METHODS

A weighted Cox regression was used to analyse height and weight at 20 years reported by 1324 carriers of MMR gene mutations (500 MLH1, 648 MSH2, 117 MSH6 and 59 PMS2) and 1219 non-carriers from the Colon Cancer Family Registry.

RESULTS

During 122,304 person-years of observation, we observed diagnoses of CRC for 659 carriers (50%) and 36 non-carriers (3%). For carriers, the risk of CRC increased by 30% for each 5 kg m(-2) increment in BMI in early adulthood (hazard ratio, HR: 1.30; 95% confidence interval, CI: 1.08-1.58; P=0.01), and increased by 64% for non-carriers (HR: 1.64; 95% CI: 1.02-2.64; P=0.04) after adjusting for sex, country, cigarette smoking and alcohol drinking (and the MMR gene that was mutated in carriers). The difference in HRs for carriers and non-carriers was not statistically significant (P=0.50). For MLH1 and PMS2 (MutLα heterodimer) mutation carriers combined, the corresponding increase was 36% (HR: 1.36; 95% CI: 1.05-1.76; P=0.02). For MSH2 and MSH6 (MutSα heterodimer) mutation carriers combined, the HR was 1.26 (95% CI: 0.96-1.65; P=0.09). There was no significant difference between the HRs for MutLα and MutSα heterodimer carriers (P=0.56).

CONCLUSION

Body mass index in early adulthood is positively associated with risk of CRC for MMR gene mutation carriers and non-carriers.

Common mental disorders and psychological distress in systemic lupus erythematosus are not associated with disease activity

Psychiatric diagnosis in patients with systemic lupus erythematosus (SLE) is controversial: variations have been reported in frequency, diagnostic assays, associations with disease activity, autoantibodies, and contributing social factors. Eighty-three consecutive non-selected Chilean patients with SLE were evaluated for: (i) 26 common mental disorders according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), using the Mini-International Neuropsychiatric Interview (MINI-plus); (ii) psychological suffering measured by Hospital Anxiety and Depression Scale (HADS); (iii) ACR 1999 neuropsychiatric (NP)SLE criteria; (iv) SLE disease activity (SLEDAI-2K); (v) cumulative damage (SLICC/ACR); and (vi) anti-ribosomal P antibodies by enzyme-linked immunoassay and immunoblot. Psychiatric diagnoses occurred in 44.6% of patients; the most frequent (21.7%) was major depressive episode (MDE). No association with lupus activity was observed in patients with a DSM-IV diagnosis or MDE or psychological suffering. ACR 1999 NPSLE criteria were present in 42.2% of patients, the majority corresponding to mood (28.9%) or anxiety disorders (15.6%). Suicidal risk was present in 9.6% of patients. Anti-ribosomal P antibodies (13.3%) were not associated with DSM-IV diagnosis. Severe psychiatric disorders in SLE are common and not associated with disease activity.

Comparison of fermentation of diets of variable composition and microbial populations in the rumen of sheep and Rusitec fermenters. II. Protozoa population and diversity of bacterial communities

Four ruminally and duodenally cannulated sheep and 8 Rusitec fermenters were used to determine the effects of dietary characteristics on microbial populations and bacterial diversity. The purpose of the study was to assess how closely fermenters can mimic the differences between diets found in vivo. The 4 experimental diets contained forage to concentrate (F:C) ratios of 70:30 (high forage; HF) or 30:70 (high concentrate; HC) with either alfalfa hay (A) or grass hay (G) as the forage. Total bacterial numbers were greater in the rumen of sheep fed HF diets compared with those fed HC diets, whereas the opposite was found in fermenters. The numbers of cellulolytic bacteria were not affected by F:C ratio in any fermentation system, but cellulolytic numbers were 2.7 and 1.8 times greater in sheep than in fermenters for HF and HC diets, respectively. Neither total bacterial nor cellulolytic numbers were affected by the type of forage in sheep or fermenters. Decreasing F:C ratio increased total protozoa and Entodiniae numbers in sheep by about 29 and 25%, respectively, but it had no effect in fermenters. Isotrichidae and Ophryoscolecinae numbers in sheep were not affected by changing F:C ratio, but both disappeared completely from fermenters fed HC diets. Total protozoa and Entodiniae numbers were greater in sheep fed A diets than in those fed G diets, whereas the opposite was found in fermenters. Results indicate that under the conditions of the present study, protozoa population in Rusitec fermenters was not representative of that in the rumen of sheep fed the same diets. In addition, protozoa numbers in fermenters were 121 and 226 times lower than those in the sheep rumen for HF and HC diets, respectively. The automated ribosomal intergenic spacer analysis of the 16S ribosomal DNA was used to analyze the diversity of liquid- and solid-associated bacteria in both systems. A total of 170 peaks were detected in the automated ribosomal intergenic spacer analysis electropherograms of bacterial pellets across the full set of 64 samples, from which 160 were detected in at least 1 individual from each system (sheep or fermenter). Diversity of liquid-associated bacterial pellets was greater with G diets in fermenters but seemed to be unaffected by diet in sheep. Bacterial diversity in solid-associated bacteria pellets was greater for G diets compared with A diets in sheep and fermenters. Different conditions in the fermenters compared with sheep rumen might have caused a selection of some bacterial strains.

Effects of dilution rate and retention time of concentrate on efficiency of microbial growth, methane production, and ruminal fermentation in Rusitec fermenters

The objective of this study was to investigate the effects of 2 dilution rates (DL) and 2 concentrate retention times (RT) on microbial growth, methane production, and fermentation of a 30:70 alfalfa hay:concentrate diet in Rusitec fermenters maintained at similar pH. The DL were 3.78 (low DL, LDL) and 5.42%/h (high DL, HDL), and concentrate RT was either 24 h (T24) or 48 h (T48). Forage RT was 48 h in all fermenters. Apparent disappearance of diet DM and NDF was greater in HDL fermenters compared with LDL fermenters, but there was a significant DL x concentrate RT interaction, showing that the effect of DL was more pronounced in T48 compared with T24 fermenters. Methane production was not affected by DL, but was greater in T48 compared with T24 fermenters, which was consistent with the increased fiber degradation in T48 fermenters. Increasing DL augmented volatile fatty acid production and molar proportions of propionate, isovalerate, and valerate, and reduced those of caproate, but no effects were observed on acetate, butyrate, and isobutyrate proportions. Increasing concentrate RT resulted in greater volatile fatty acid production and proportions of acetate, butyrate, and caproate, but reduced those of propionate, valerate, and isovalerate. Ammonia-N production was not affected by concentrate RT, but was greater at HDL compared with LDL. Microbial growth was not affected by DL, but microbial growth efficiency was lower in HDL compared with LDL fermenters. Concentrate RT affected microbial growth and its efficiency, with both being greater in T48 compared with T24 fermenters. Carboxymetylcellulase and xylanase activities in ruminal fluid were greater in HDL compared with LDL fermenters, but were not affected by concentrate RT. There were DL x concentrate RT interactions for diet apparent disappearance, molar proportions of propionate, butyrate, isovalerate, and caproate, and acetate:propionate ratio, indicating that effects of DL on these variables were influenced by concentrate RT. The results would indicate that using higher DL and shorter concentrate RT than those typically used in Rusitec fermenters would contribute to improving the simulation of in vivo fermentation of high-concentrate diets.

Microbial protein synthesis, ruminal digestion, microbial populations, and nitrogen balance in sheep fed diets varying in forage-to-concentrate ratio and type of forage

Six ruminally and duodenally cannulated sheep were used in a partially replicated 4 x 4 Latin square to evaluate the effects of 4 diets on microbial synthesis, microbial populations, and ruminal digestion. The experimental diets had forage to concentrate ratios (F:C; DM basis) of 70:30 (HF) or 30:70 (HC) with alfalfa hay (A) or grass hay (G) as forage and were designated as HFA, HCA, HFG, and HCG. The concentrate was based on barley, gluten feed, wheat middlings, soybean meal, palmkern meal, wheat, corn, and mineral-vitamin premix in the proportions of 22, 20, 20, 13, 12, 5, 5, and 3%, respectively (as-is basis). Sheep were fed the diets at a daily rate of 56 g/kg of BW(0.75) to minimize feed selection. High-concentrate diets resulted in greater (P < 0.001) total tract apparent OM digestibility compared with HF diets, but no differences were detected in NDF digestibility. Ruminal digestibility of OM, NDF, and ADF was decreased by increasing the proportion of concentrate, but no differences between forages were detected. Compared with sheep fed HF diets, sheep receiving HC diets had less ruminal pH values and acetate proportions, but greater butyrate proportions. No differences among diets were detected in numbers of cellulolytic bacteria, but protozoa numbers were less (P = 0.004) and total bacteria numbers tended (P = 0.08) to be less for HC diets. Carboxymethylcellulase, xylanase, and amylase activities were greater for HC compared with HF diets, with A diets showing greater (P = 0.008) carboxymethylcellulase activities than G diets. Retained N ranged from 28.7 to 37.9% of N intake and was not affected by F:C (P = 0.62) or the type of forage (P = 0.31). Microbial N synthesis and its efficiency was greater (P < 0.001) for HC diets compared with HF diets. The results indicate that concentrates with low cereal content can be included in the diet of sheep up to 70% of the diet without detrimental effects on ruminal activity, microbial synthesis efficiency, and N losses.

Evaluation of procedures for detaching particle-associated microbes from forage and concentrate incubated in Rusitec fermenters: efficiency of recovery and representativeness of microbial isolates

Three detachment procedures (DP) were evaluated for their ability to remove particle-associated microbes from digesta in Rusitec fermenters fed a 30:70 alfalfa hay:concentrate diet. Forage and concentrate were incubated in separate nylon bags, and incubation residues were treated independently. Microbial biomass was labeled with (15)NH(4)Cl. Treatments were 1) MET: residues were incubated at 38 degrees C for 15 min with saline solution (0.9% NaCl) containing 0.1% methylcellulose with continuous shaking; 2) STO: residues were mixed with cold saline solution and homogenized with a stomacher for 5 min at 230 revolutions per min; and 3) FRE: residues were immediately frozen at -20 degrees C for 72 h, thawed at 4 degrees C, mixed with saline solution, and subjected to STO procedure. Common to all treatments was storing at 4 degrees C for 24 h after the treatment, homogenization, filtration, and resuspension of residues 2 times in the treatment solutions. Microbial pellets were obtained by centrifugation, and microbial removal was estimated indirectly by measuring removal of (15)N. The PCR-single-stranded conformation polymorphism analysis of the 16S ribosomal DNA was used to analyze the similarity between microbial communities attached to the substrate and those in the pellet obtained after each DP. There were no feed x DP interactions (P = 0.16 to 0.96) for any variable, except for N content in microbial pellets (P = 0.02). Detaching efficiency (P = 0.004) and total recovery (P = 0.01) were affected by DP, with STO showing the greatest values (mean values across substrates of 64.1% for detaching efficiency and 58.3% for total recovery) and MET the least values (57.0 and 51.8%). Similarity index between the microbes attached to substrates and those in the pellets were affected (P = 0.02) by DP, with MET showing greater (P < 0.02) values (84.0 and 86.4% for forage and concentrate, respectively) than FRE (72.5 and 67.8%) and STO having intermediate values (77.1 and 82.4%). There were no differences (P = 0.70) among particle-associated microbe pellets in their N content, but MET pellets had greater (P < 0.05) (15)N enrichments than those obtained by STO and FRE. Although STO was the most effective method to detach ruminal microbes from concentrate and forage, MET produced pellets with the greatest similarity to the microbial communities attached to the substrates and therefore could be considered the most appropriate DP method for treating digesta from Rusitec fermenters.

Alumina particles influence the interactions of cocultured osteoblasts and macrophages

The purpose of the current study was to evaluate the effects of alumina particles on secretion of several cytokines involved in bone resorption in cocultures of macrophages and osteoblasts. To distinguish the contribution of each individual cell type, we have established a heterologous in vitro system that makes use of mouse J774 cells and primary cultured human osteoblasts. J744 cells decreased the production of TNF-alpha when they were cocultured with osteoblasts. Treatment of J744 cells with alumina particles increased TNF-alpha secretion, but the induction was lower when cells were cocultured with osteoblasts. Secretion of IL-6 by J744 cells was very low, and increased in the presence of osteoblasts. Alumina particles were only able to stimulate the release of IL-6 by J744 cells when cells were cocultured with osteoblasts. On the other hand, incubation of osteoblasts with alumina particles enhanced the release of IL-6 and GM-CSF. Coculturing osteoblasts with J744 cells induced them to release IL-6 and GM-CSF, and treatment with alumina further increased the secretion of both mediators by osteoblasts. According to these in vitro results, it seems rather plausible that alumina particles are able to initiate an inflammatory response in vivo.

Abnormalities in the bone mineral metabolism in HIV-infected patients

OBJECTIVE

To evaluate bone mineral metabolism in HIV infected and asymptomatic patients receiving highly active antiretroviral therapy (HAART) containing protease inhibitors (PI) and naïve patients.

METHODS

We studied 30 asymptomatic HIV infected male patients, 13 in the naive group and 17 in the IP group, both without differences in demographics characteristics. We excluded women and patients with any known factor associated to osteopenia. We did a nutritional questionnaire, a DEXA scan in lumbar spine and femur, a study of CD4 lymphocytes, viral load and an analysis of bone formation and resorption markers in all patients. We compared vitamin D and PTH levels with a control group of healthy male volunteers age-pareated. For the statistical analysis we used the SPSS program.

RESULTS

Osteopenia was present in 17/30 (57%), 8/13 (61.5%) in the naïve group and 9/17 (53%) in the PI group (not significant differences). We found a vitamin D deficiency in 86% of patients, with mean serum levels that was found to be significantly lower than those from a healthy control group (p=0.04). Testosterone level was significantly related to bone mineral density in lumbar spine (p</=0.05).

CONCLUSIONS

HIV may be an individual risk factor in bone disorders, requiring calcium and vitamin D supplementation.

In vitro corrosion behaviour and osteoblast response of thermally oxidised Ti6Al4V alloy

In this work, the influence of thermal oxidation treatments of Ti6Al4V at 500 degrees C and 700 degrees C for 1 h on the in vitro corrosion behaviour and osteoblast response is studied. The potential of these treatments, aimed to improve the wear surface performance as biomaterial, relies in the formation of an outer "ceramic" layer of rutile. The corrosion behaviour was evaluated in simulated human fluids by electrochemical impedance spectroscopy and anodic polarisation tests. The effect of these thermal oxidation treatments on osteoblastic behaviour was studied in primary cultures of human osteoblastic cells. Results show that thermal oxidation treatments do not decrease the high in vitro corrosion resistance of the Ti6Al4V alloy. Osteoblast adhesion studies indicate that thermal oxidation treatments do not impair the material biocompatibility. Moreover, the thermal oxidation at 700 degrees C enhances the in vitro osteoblastic cell attachment compared to the thermal oxidation at 500 degrees C.

Age-related changes in parathyroid hormone-related protein and vascular endothelial growth factor in human osteoblastic cells

Osteogenesis and angiogenesis occur in a coordinated manner in skeletal tissue, so that impaired angiogenesis is associated with decreased bone formation in aged subjects. However, the interaction between bone endothelium and osteoblastic cells is poorly understood. Parathyroid hormone-related protein (PTHrP), a bone factor which modulates osteoblastic cell growth and/or differentiation, stimulates vascular endothelial growth factor (VEGF), a potent angiogenic factor, in primary cultures of human osteoblastic (hOB) cells. In the present study, we examined the age-related changes of both factors in these cells. Human OB cells were isolated from trabecular bone samples from knee or hip explants obtained from 45 osteoarthritic patients: 12 <60 years (21-59 years), 5 women and 7 men, and 33 >60 years (61-82 years), 20 women and 13 men. Cell total RNA was isolated, and mRNA analysis was performed by reverse transcription-polymerase chain reaction. Relative ratios of amplified products with respect to glyceraldehyde-3-phosphate dehydrogenase were then calculated. PTHrP and VEGF were measured in the cell-conditioned medium, after stimulation with (or without) 10 nM 1,25(OH)(2)D(3) for 72 h, using specific immunoradiometric assay and a competitive immunoassay, respectively. A positive correlation was found between PTHrP and VEGF (both mRNA and secreted protein), and also between PTHrP mRNA and the secreted protein levels, in these cells. PTHrP, both mRNA and protein secretion levels, and VEGF secreted values were higher in knee hOB cells than in hip hOB cells only in the younger group. In addition, a decrease in the secreted levels of these factors occurs with aging only in hOB cells from knee. Treatment with 10 nM 1,25(OH)(2)D(3) induced a lower inhibitory response of PTHrP secretion, and a higher stimulatory response of secreted VEGF, in hOB cells with age. These findings indicate that age-related bone loss in humans is associated with a decrease in the osteoblastic secretion of both PTHrP and VEGF in the knee, a predominantly trabecular bone. These data might provide a rationale to explain the impaired angiogenesis associated with trabecular bone loss in aging.

Antiribosomal P protein antibodies in Chilean SLE patients: no association with renal disease

The objective of this work was to determine the frequency and clinical associations of anti-ribosomal P protein antibodies (Anti-P) in a cohort of Chilean patients with systemic lupus erythematosus (SLE). Between 1996 and 1998, 141 consecutive patients with SLE were examined prospectively according with a standard protocol. Disease activity was measured by MEX-SLEDAI in 138 patients. Anti-P positivity was determined by double immune diffusion or Western blot and ELISA. Anti-P was found in 21 (15%) patients. In the Anti-P positive patients recent onset SLE (disease duration of 1 year or less) was more frequent (P = 0.018). Anti-P was found in 23% of 83 patients with active SLE vs 4% of the 55 patients with inactive SLE (Yates corrected P = 0.00479). An association with anti-dsDNA antibodies by Farr assay was observed. Anti-P positive patients had a median Farr of 65 IU/ml (1.4-1240) and Anti-P negative of 12 IU/ml (1.4-992; P-value = 0.0084). During the study only two patients had lupus psychosis and they were Anti-P positive. No association was found with liver disease (six patients, two with Anti-P antibodies) or active glomerulonephritis (22 patients four with Anti-P). Our data shows that the presence of Anti-P antibodies supports the clinical diagnosis of lupus psychosis.

[Prostate neoplasm prevalence in Talca, VII Region of Chile]

BACKGROUND

In 1998, there were 1,218 deaths in Chile caused by prostate cancer. This figure results in a death rate of 16.6 per 100,000 males for this disease.

AIM

To assess the prevalence of prostate cancer in the Seventh Region of Chile.

MATERIAL AND METHODS

A probabilistic sample of 327 males aged 40 to 59 years old was studied. In all, a codified questionnaire was applied, a digital rectal examination was performed and a blood sample was drawn to measure prostate specific antigen. All digital rectal examinations were performed by the same observer. Patients with an abnormal rectal examination or prostate specific antigen were subjected to a prostatic biopsy under ultrasound guidance.

RESULTS

In 14 subjects, the digital rectal examination was considered abnormal and in seven, prostate specific antigen was over 4 ng/ml. All subjects with elevated prostate specific antigen had an abnormal rectal examination. In three of the 14 subjects, the biopsy showed a well differentiated adenocarcinoma. All three were aged over 50 years old. The resulting calculated prevalence of prostate cancer was 9.2 per 1,000 males (CI 4.2-14.1).

CONCLUSIONS

The cost effectiveness of screening for early diagnosis of prostate cancer must be calculated, to decide its incorporation in preventive medical examinations.

Changes in osteocalcin response to 1,25-dihydroxyvitamin D(3) stimulation and basal vitamin D receptor expression in human osteoblastic cells according to donor age and skeletal origin

Age-related osteopenia is known to occur differently throughout the skeleton. In the present study, we examine the influence of donor age (<50 and >50 years), and bone structure (cortical vs. trabecular) on osteocalcin and vitamin D receptor (VDR) expression in primary cultures of human osteoblastic cells (hOB) cells. Cells were isolated from trabecular bone samples obtained from donors undergoing either knee (mainly trabecular) (n = 22; 4 <50 years, 18 >50 years) or hip (mainly cortical) (n = 16; 6 <50 years, 10 >50 years) arthroplasty. Pooling the results from knee and hip hOB cell cultures, we found that secreted osteocalcin was higher in hOB cells from the younger donors, compared with that in older donors, and peaked after stimulation with 10(-6)--10(-8) mol/L 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)]. In cells from the latter donors, this secretion was maximal after 10(-6) mol/L 1,25(OH)(2)D(3) treatment. On the other hand, using reverse transcription followed by polymerase chain reaction, baseline osteocalcin mRNA was found to be lower in hOB cells from the older donors than in those from younger donors. After treatment with 10(-6)--10(-8) mol/L 1,25(OH)(2)D(3), osteocalcin mRNA increased over baseline in all groups of hOB cells studied. In age-matched cultures, both basal and 10(-6)--10(-8) mol/L 1,25(OH)(2)D(3)-stimulated osteocalcin mRNA showed similar values in hOB cells from both skeletal sites in younger donors. However, in the older donors, baseline as well as 10(-8) mol/L 1,25(OH)(2)D(3)-stimulated osteocalcin mRNA were higher in knee hOB cells than in hip hOB cells. Furthermore, baseline VDR mRNA expression was also higher in the former cells than in the latter cells in the older group. Considering the influence of donor age at each skeletal site of origin, we found lower baseline osteocalcin and VDR mRNA levels in hip hOB cells in the older group than in the younger group. Our findings indicate that the response of osteocalcin secretion and its mRNA to physiological doses of 1,25(OH)(2)D(3) decreases with aging and is associated with decreased VDR mRNA expression in hOB cells from mainly cortical bone.

Influence of particle size in the effect of polyethylene on human osteoblastic cells

The influence of two different sizes of polyethylene particles (< 30 and 20-200 microm) on osteoblastic function has been studied in primary human bone cell cultures. Cells were obtained from trabecular bone fragments of patients undergoing knee reconstructive surgery. On reaching confluency, cells were subcultured in three flasks: < 30 microm polyethylene particles were added to the first flask, 20-200 microm particles to the second flask and none to the third flask, which was the control. The resulting subcultures were incubated until confluence. Osteoblastic function was evaluated by assaying the secretion of osteocalcin, alkaline phosphatase, and C-terminal type I procollagen (PICP), with or without 1.25(OH)2D3 stimulation in the cell-conditioned medium. Adding < 30 microm polyethylene particles to these osteoblastic cell cultures increased the levels of osteocalcin secreted after 1,25(OH)2D3 stimulation. Treating stimulated or basal osteoblastic cultures with either polyethylene particle size did not affect alkaline phosphatase secretion. However, the addition of <30 microm polyethylene particles decreased PICP levels in the basal and stimulated cultures. A parallel series of osteoblastic cultures was treated with < 30 microm polyethylene particles and stimulated or not with 1,25(OH)2D3 to determine the effect on osteocalcin mRNA expression using RT-PCR amplification. Polyethylene particle-treated cultures had higher osteocalcin mRNA expression regardless of whether they had been stimulated with 1,25(OH)2D3 or not. We conclude that particle size affects the influence of polyethylene on osteoblastic function markers. Particles with a diameter of less than 30 microm increase osteocalcin expression and secretion.

Adenoma characteristics as risk factors for recurrence of advanced adenomas

BACKGROUND AND AIMS

The link between adenoma characteristics at baseline colonoscopy and adenoma recurrence is poorly understood. We assessed whether the number, size, location, or histology of resected adenomas was related to the probability of recurrence of advanced lesions.

METHODS

Analyses were based on 1287 men and women in the wheat bran fiber (WBF) study, a randomized, double-blind trial of WBF as a means of decreasing the probability of adenoma recurrence over a period of 3 years. Multiple logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Recurrence of advanced adenomas (>1 cm or tubulovillous/villous histology) was higher among individuals with adenomas >1 cm compared with those with adenomas <0.5 cm (OR, 2.69; 95% CI, 1.34-5.42) and among those with proximal than those with distal adenomas (OR, 1.65; 95% CI, 1.02-2.67). No association was observed for adenoma number or histology. A shift in location from the distal colon and rectum at baseline (54.6%) to more proximal recurrent adenomas (45.2%), including advanced lesions (42.8%), was observed.

CONCLUSIONS

Large or proximally located adenomas are important indicators of recurrence of advanced lesions. Because most recurrences were detected in the proximal colon, careful surveillance of this area is warranted.

Cultures of human osteoblastic cells from dialysis patients: influence of bone turnover rate on in vitro selection of interleukin-6 and osteoblastic cell makers

The factors contributing to renal osteodystrophy are still incompletely characterized. A variety of cytokines and growth factors appear to have ill-defined roles in this disease. Our aim is to compare osteoblastic cell growth and different osteoblastic markers in vitro with histomorphometric bone parameters and some serum bone-turnover markers in vivo in dialysis patients with either high- (HTBD) or low-turnover (LTBD) bone disease. Six patients were diagnosed to have LTBD, and another five patients, HTBD. Intact parathyroid hormone (PTH) and osteocalcin (OC) levels in serum were greater in patients with HTBD than in those with LTBD. Osteoblastic cells isolated from iliac crest biopsy specimens were grown in culture medium for different times up to 13 days. Osteoblastic cell growth (cell number and area under the cell growth curve) was greater in patients with HTBD than in those with LTBD. Static and dynamic bone formation parameters correlated with serum PTH levels. No correlation was found between PTH and osteoblastic cell proliferation. OC, C-terminal type I procollagen, and alkaline phosphatase osteoblastic secretion in vitro were similar in the HTBD and LTBD groups. However, interleukin-6 (IL-6) secretion was greater in cells isolated from patients with LTBD. Our results indicate that osteoblastic cell growth and osteoblastic IL-6 secretion are related to bone turnover in patients with osteodystrophy. Our findings support the hypothesis that factors other than PTH level might have an important role in affecting osteoblastic function in renal osteodystrophy.

Effects of MA 956 superalloy and alpha-alumina particles on some markers of human osteoblastic cells in primary culture

One of the problems associated with the modern biomaterials used in prostheses is osteolysis, which, although its exact origin is unknown, has been associated with wear particles. Osteoblasts seem to participate directly in this phenomenon. This paper investigates in vitro cellular response to the wear particles from the metal substrate and ceramic covering (alpha-alumina) of a new titanium yttrium aluminum alloy, MA 956, that has been proposed as a biomaterial because of its exceptional mechanical and electrochemical properties. The effect of different sizes (10 and 80 microm) of MA 956 and alpha-alumina particles on osteoblast function was studied in primary human bone cell cultures. Cells were harvested from trabecular bone fragments obtained during knee arthroplasty. Osteoblastic cell response to the particles was measured by assaying C-terminal type I procollagen (PICP), alkaline phosphatase, and osteocalcin secretion, with and without 1.25(OH)(2)D(3) stimulation, in the cell-conditioned medium. Both sizes of MA 956 and alpha-alumina particles decreased PICP secretion in nonstimulated osteoblastic cells, but this secretion was not affected in the cultures stimulated with 1.25(OH)(2)D(3). Only the 10 microm alpha-alumina particles inhibited alkaline phosphatase activity in 1.25(OH)(2)D(3)-stimulated and nonstimulated cultures. The rise in osteocalcin levels after 1.25(OH)(2)D(3) stimulation was lower in the presence of the 10 microm MA 956 particles than in the presence of alpha-alumina particles. Although both materials seem to have directly affected in vitro osteoblastic cell function, the increase in osteocalcin levels after 1.25(OH)(2)D(3) stimulation was lower after exposure to MA 956 particles than the increase observed after exposure to alpha-alumina particles. Therefore, it does not seem that osteocalcin stimulated bone resorption, suggesting that MA 956 would be less likely to provoke osteolysis.

[Methods to assess the ex vivo growth capacity of mesothelial cells obtained directly from peritoneal effluent]

The anatomical and functional integrity of mesothelial cells (MC) is necessary for peritoneal membrane stability. At present, there is no satisfactory method to assess MC function and regenerative capacity in individual peritoneal dialysis (PD) patients. MC may be cultured from peritoneal biopsy specimens, but peritoneal biopsy is an invasive procedure that cannot be performed serially. The aim of this study is to explore the feasibility of serial culture of MC from the peritoneal effluent of PD patients. Fifty-two randomly selected PD patients were studied. MC were obtained from the peritoneal effluent of nocturnal 2.27% glucose exchanges and cultured in T25 tissue culture flasks. Subconfluent MC cultures were obtained in 80.7% of patients. At this stage, the percentage of cells in the tissue cultured flask characterized as MC by morphology and immunostaining had increased to 95.5%. MC were then subcultured in multi-well culture plates, where they showed exponential cell growth until day 16. Nine (17%) patients released low numbers of MC into the effluent and MC could not be cultured to subconfluence. One additional patient released and apparently adequate number of MC that repeatedly failed to reach confluence. Patients showed the same behavior in several cultures performed. In conclusion, peritoneal MC released into peritoneal effluent are accessible for profound analysis by a culture technique. This technique opens the possibility of serial follow-up of the biology of MC individual PD patients.

Lack of effect of a high-fiber cereal supplement on the recurrence of colorectal adenomas. Phoenix Colon Cancer Prevention Physicians' Network

BACKGROUND

The risks of colorectal cancer and adenoma, the precursor lesion, are believed to be influenced by dietary factors. Epidemiologic evidence that cereal fiber protects against colorectal cancer is equivocal. We conducted a randomized trial to determine whether dietary supplementation with wheat-bran fiber reduces the rate of recurrence of colorectal adenomas.

METHODS

We randomly assigned 1429 men and women who were 40 to 80 years of age and who had had one or more histologically confirmed colorectal adenomas removed within three months before recruitment began to a supervised program of dietary supplementation with either high amounts (13.5 g per day) or low amounts (2 g per day) of wheat-bran fiber. The primary end point was the presence or absence of new adenomas at the time of follow-up colonoscopy. Subjects and physicians, including colonoscopists, were unaware of the group assignments.

RESULTS

Of the 1303 subjects who completed the study, 719 had been randomly assigned to the high-fiber group and 584 to the low-fiber group. The median times from randomization to the last follow-up colonoscopy were 34 months in the high-fiber group and 36 months in the low-fiber group. By the time of the last follow-up colonoscopy, at least one adenoma had been identified in 338 subjects in the high-fiber group (47.0 percent) and in 299 subjects in the low-fiber group (51.2 percent). The multivariate adjusted odds ratio for recurrent adenoma in tile high-fiber group, as compared with the low-fiber group, was 0.88 (95 percent confidence interval, 0.70 to 1.11; P=0.28), and the relative risk of recurrence according to the number of adenomas, in the high-fiber group as compared with the low-fiber group, was 0.99 (95 percent confidence interval, 0.71 to 1.36; P=0.93).

CONCLUSIONS

As used in this study, a dietary supplement of wheat-bran fiber does not protect against recurrent colorectal adenomas.

[High prevalence of vitamin D deficiency in postmenopausal women at a rheumatology office in Madrid. Evaluation of 2 vitamin D prescription regimens]

BACKGROUND

Vitamin D deficiency has been frequently observed in the elderly population in Europe. However few information is available about the vitamin D status in postmenopausal women in the Mediterranean countries. The aim of this study was to evaluate the vitamin D status assessed by serum 25(OH)D3 (calcidiol) in postmenopausal women who attended a Rheumatology practice in Madrid area, and to evaluate calcidiol serum levels through one year after two forms of vitamin D administration.

PATIENTS AND METHODS

Calcidiol serum levels were measured in 171 postmenopausal women (111 with osteoporosis and 60 without osteoporosis). 82 women with calcidiol serum levels < 10 ng/ml were distributed in two groups: Group I received 800 U/day of vitamin D3 associated with calcium (1 g/day) and group II, one dose of 80,000 U vitamin D orally as calcidiol and latter a daily dose of 800 U vitamin D3 plus 1 g calcium. Calcidiol serum levels were measured by RIA in both groups at basal condition and after three, six and twelve months under treatment.

RESULTS

Three cut-offs were considered: 10, 15 and 20 ng/ml of calcidiol. Percentages of postmenopausal women with vitamin D deficiency for such cut-offs were: 35.3%, 64.1% and 87.1%, respectively. After three months of treatment, women from group II showed calcidiol serum levels higher than group I. At six and twelve months calcidiol serum levels were similar in both groups.

CONCLUSIONS

A high prevalence of vitamin D deficiency was observed in a group of postmenopausal women who attended a rheumatology practice in Madrid area. Both forms of vitamin D administration seem not sufficient to maintain the adequate calcidiol serum levels in postmenopausal deficient women. A dose of 80,000 U of calcidiol twice a year should be considered.

Low vitamin D levels in outpatient postmenopausal women from a rheumatology clinic in Madrid, Spain: their relationship with bone mineral density

To evaluate a possible relationship between vitamin D levels and bone mineral density (BMD) and the prevalence of hypovitaminosis in a population of postmenopausal women from a rheumatologic outpatient clinic in Madrid, Spain, 171 postmenopausal women (aged 47-66 years) divided into two groups (osteoporotic and nonosteoporotic, according to WHO criteria) were studied between November and June. Liver and kidney function were normal in all subjects. Serum parathyroid hormone (PTH) and calcidiol levels were determined and bone densitometry carried out at the lumbar spine and hip level. PTH and calcidiol serum levels did not show any correlation. Serum PTH was inversely related to BMD at both hip and lumbar spine in the total group, and at the hip with calcidiol levels lower than 37 nmol/l. Calcidiol was directly related to hip BMD only when levels were lower than 37 nmol/l. Results of a stepwise multiple regression analysis showed that the single factor which affected BMD at the hip was calcidiol in the subgroup with serum calcidiol levels below 37 nmol/l, while in the subgroup with serum calcidiol levels above 37 nmol/l, the main factor affecting hip BMD was serum PTH. The prevalence of vitamin D deficiency at a cutoff of 37 nmol/l was 64%. In summary, calcidiol serum levels below 37 nmol/l seem to affect bone mass, regardless of the effect of PTH. Vitamin D deficiency is a frequent finding in the postmenopausal women who attend a rheumatology outpatient clinic in Madrid. Vitamin D supplementation should therefore be considered in this population during the winter season.

Risk factors for Ki-ras protooncogene mutation in sporadic colorectal adenomas

The Ki-ras protooncogene frequently is mutated in colorectal adenocarcinomas, but the etiology of this molecular event is uncertain. We investigated the association between variables known or suspected to be related to risk for colorectal cancer and the occurrence of Ki-ras mutations in colorectal adenomas. This study was conducted among 678 male and female participants, 40-80 years of age, enrolled in a phase III trial testing the effects of a wheat bran fiber supplement on adenoma recurrence. Exposure information on the risk factors of interest was assessed through self-administered questionnaires. Mutations in codons 12 and 13 of the Ki-ras protooncogene were analyzed in baseline adenomas 0.5 cm or larger by PCR amplification followed by direct sequencing. Eighteen percent (120 of 678) of the participants had one or more adenoma(s) with Ki-ras mutations. A higher risk of Ki-ras mutations was associated with increasing age and a lower intake of total folate. The odds ratio (OR) for Ki-ras mutations for individuals >72 years of age was 1.98 [95% confidence interval (CI) = 1.19-3.27; P for trend = 0.008] compared with those less than 65 years of age. Compared with individuals in the lower tertile of total folate, those in the upper tertile had an approximately 50% lower risk of having Ki-ras mutation-positive adenomas (OR = 0.52; 95% CI = 0.30-0.88; P for trend = 0.02). There was a suggestion of a stronger inverse association of total folate with G-->T transversions (OR = 0.41; 95% CI = 0.20-0.87) than G-->A transitions (OR = 0.61; 95% CI = 0.31-1.21), although the CIs for the associations overlap. The results of these analyses suggest that the protective effect of folate in colon cancer observed in published studies may be mediated through folate's effect on Ki-ras mutations.

Reliability and validity of a self-administered food frequency questionnaire in a chemoprevention trial of adenoma recurrence

Various chemoprevention trials have assessed dietary intake by means of food frequency questionnaires. However, it is important to assess the degree to which such questionnaires can measure diet. We conducted reproducibility and validity analyses of our Arizona Food Frequency Questionnaire (AFFQ) in our recently completed, randomized, Phase III chemoprevention trial testing the effects of a wheat bran fiber supplement on colorectal adenoma recurrence. A total of 139 individuals provided a baseline and year 1 AFFQ and a set of 4-day dietary records collected over a period of 1 month. The reproducibility analyses of the AFFQ administered 1 year apart showed a mean intraclass correlation of 0.54 for unadjusted nutrients and 0.48 for energy-adjusted nutrients. The relative validity of the AFFQ, as compared with the average of the 4-day diet records, showed a mean deattenuated correlation of 0.49 (range, 0.22-0.65) for the baseline AFFQ and 0.49 (range, 0.25-0.67) for the year 1 AFFQ. When data from both AFFQs were combined and compared with the diet records, there was a slight improvement in the overall deattenuated correlations (mean, 0.56; range, 0.33-0.71). The correlations we observed for macro- and micronutrient intake were within the overall range of those reported in the literature. Reliability and validity studies of dietary instruments are feasible in the setting of a chemoprevention trial and should be conducted when the instrument's performance has not been previously assessed in the target population.

Lack of relationship between BsmI vitamin D receptor polymorphism and primary hyperparathyroidism in a Spanish female population

The role of vitamin D receptor (VDR) gene polymorphisms in the pathogenesis of hyperparathyroidism is uncertain. Controversial results have been reported. The aim of this study was to explore the relevance of BsmI VDR gene polymorphism in patients with primary hyperparathyroidism (PHPT) due to adenomas. For this purpose, 36 postmenopausal patients with PHPT, mean age 64 years, were compared with a normal age-matched female population (n = 81). BsmI polymorphism distribution in PHPT group was as follows: Bb 50% (18/36); BB 22% (8/36); bb 28% (10/36). In the control group, the distribution was Bb 49% (40/81); BB 16% (13/81); bb 35% (28/81). No statistical differences were found between the two groups. In the PHPT group, no statistical associations were found between different allelic distribution and age, creatinine, hematocrit, phosphorus, alkaline phosphatase (ALP), total calcium, serum parathyroid hormone (PTH), or gland weight. By contrast, levels of serum calcium and iPTH values positively correlated with the PT weight (r = 0.421 and 0.599, respectively, P = 0.0001). Our data suggest that at least in this group, BsmI VDR gene polymorphism appears to be of minor relevance in clinical presentation and possibly, tumorigenesis in PHPT due to adenomas.

Physical activity, body mass index, and prostaglandin E2 levels in rectal mucosa

BACKGROUND

Evidence suggests a relationship between prostaglandin levels in colonic mucosa and risk of colon cancer. Physical inactivity and a higher body mass index (BMI; weight in kilograms divided by [height in meters]2) have been consistently shown to increase risk of this cancer. We investigated whether higher levels of leisure-time physical activity or a lower BMI was associated with lower concentrations of prostaglandin E2 (PGE2) in rectal mucosa.

METHODS

This study was conducted in 41 men and 22 women, 42-78 years of age, with a history of polyps, who participated in a randomized clinical trial testing the effects of piroxicam on rectal mucosal PGE2 levels. An [125I]PGE2 radioimmunoassay kit was used to determine PGE2 levels in samples of extracted rectal mucosa collected before randomization. Leisure-time physical activity was assessed through a self-administered questionnaire collected at baseline. The reported time spent at each activity per week was multiplied by its typical energy expenditure, expressed in metabolic equivalents (METs), to yield a MET-hours per week score. A repeated measures model was used to assess the effect of BMI and physical activity as predictors of PGE2 concentration. All statistical tests were two-sided.

RESULTS

After adjustment for age, a higher BMI was associated with higher PGE2 levels (P = .001). A higher level of leisure-time physical activity was inversely associated with PGE2 concentration (P<.03). An increase in BMI from 24.2 to 28.8 kg/m2 was associated with a 27% increase in PGE2. An increase in activity level from 5.2 to 27.7 MET-hours per week was associated with a 28% decrease in PGE2.

CONCLUSIONS

Physical activity and obesity may alter the risk of colon cancer through their effects on PGE2 synthesis.

[Polymorphism of the gene of vitamin D receptor and bone mineral density in postmenopausal women]

BACKGROUND

Conflicting results have been reported on the association between restriction fragment length polymorphism at the vitamin D receptor (VDR) gene locus and bone mineral density (BMD). Population differences in environmental factors, such as calcium intake and calcidiol levels which have strong influence in BMD, may alter this association.

PATIENTS AND METHODS

We analyzed the Bsml RFLP at the eight introm of the VDR gene in a population sample (n = 204) of postmenopausal Spanish women aged 50-65 years being seen clinically and studied calcium intake (dietetic questionnaire) and biochemical parameters (PTH and calcidiol). In parallel bone densitometry were measured in lumbar spine and proximal femur.

RESULTS

We identified low BMD of the proximal femur in the BB group. This effect was not observed at other body locations. The calcium intake was lees than 500 mg/day in 60% of the studied population as calcidiol levels were lower than 10 ng/l in 36% of it. The total group population with normal calcium intake (> 1,000 mg/day) showed higher BMD (proximal femur and spine) than the group with low calcium intake, this variation not being observed in group BB alleles. Interestingly, we observed significant differences in BMD proximal femur between genotype groups BB versus Bb + bb when calcidiol levels were < 10 ng/l. Moreover, within the BB subgroup, those subjects with normal calcidiol levels have higher proximal femur BMD compared with those with low calcidiol levels.

CONCLUSIONS

Our results indicate an effect of the VDR genotype on BMD proximal femur which is clearly influenced by calcium intake and calcidiol serum levels.

[Capacity to predict a recurrence of lupus erythematosus using double-stranded anti-DNA antibodies and Farr technique]

BACKGROUND

Patients with inactive systemic lupus erythematosus (SLE) and elevated high affinity double-stranded anti-DNA antibodies (anti-dsDNA), measured using Farr technique, would have a risk of relapse that fluctuates between 40 to 80% according to different series.

AIM

To study the association between anti-dsDNA levels measured using Farr technique and disease activity and their predictive capacity for relapses.

MATERIAL AND METHODS

Anti-dsDNA antibodies were measured according to Farr method in 60 healthy subjects, 69 patients with other connective tissue diseases and in 120 patients with SLE. Farr positive were considered those individuals with anti-dsDNA levels over 10.4 IU/ml. Disease activity, assessed using MEX-SLEDAI score was related with anti-dsDNA levels in 101 patients. Forty seven patients with inactive disease were followed for 17 +/- 14 months.

RESULTS

Anti-dsDNA levels were 3 +/- 2.5 IU/ml (range 1-26) in subjects without LED, and 127 +/- 500 IU/ml (range 1-5280) in patients with LED. Sixty subjects had an active SLE and 43 (72%) were Farr positive; in 41 the disease was inactive and 13 (32%) were Farr positive (p < 0.001), OR 5.45. Twelve of the 47 followed patients had a relapse and 10 (83%) were Farr positive. Of those that did not have a relapse, 13 (37%) were Farr positive (p < 0.02, RR 5.22). Six of 15 patients that were followed for more than on year (40%), were Farr positive.

CONCLUSIONS

Elevated anti-dsDNA antibodies measured using Farr technique in patients with inactive generalised lupus erythematosus, predicted the risk of relapse. However less than half of patients with inactive disease and elevated Farr relapsed in a period of one year. The need to treat patients with inactive SLE and positive Farr should therefore be considered debatable.

Influence of skeletal site of origin and donor age on osteoblastic cell growth and differentiation

Bone loss with aging may be due, at least in part, to inadequate bone formation. Moreover, the process of bone aging is known to follow a different pattern throughout the skeleton. In this study, we examined the cell proliferation rate (area under the cell growth curve, AUC) and the secretion of C-terminal type I procollagen (PICP), alkaline phosphatase (ALP), and osteocalcin (OC) in primary cultures of osteoblastic cells from human trabecular bone. Osteoblastic cells were obtained for 168 donors (100 women and 68 men). Ninety-eight bone samples were obtained from subjects undergoing knee arthroplastia, 52 aged 50-70 years (64 +/- 5) and 46 over age 70 (73 +/- 2). Another 70 bone samples were obtained from subjects undergoing hip arthroplastia; 51 were 50-70 years old (64 +/- 4) and 19 were over 70 (75 +/- 5). Osteoblastic cells from the older donors had a lower proliferation rate and OC secretion than those from younger subjects. However, ALP secretion was higher in the former subjects, whereas PICP secretion was unchanged. Osteoblastic cells from hip had a lower proliferation rate than those from knee. PICP secretion was also lower and ALP secretion was higher in the former cells. In age-matched cell cultures, osteoblastic cells from the knee had higher proliferation rate and PICP secretion than osteoblastic cells from the hip. However, ALP secretion was lower in knee osteoblastic cells than those from hip only in the younger group. With aging, ALP secretion was found to increase in knee osteoblactic cells, whereas OC secretion decreased in osteoblastic cell cultures from the hip. Our findings suggest that bone loss with aging may be accounted for, at least in part, by a decreased osteoblastic cell proliferation and an increased osteoblastic maturation. In addition, our data indicate that these changes with aging do not occur similarly at different skeletal sites.

Influence of skeletal site of origin and donor age on 1,25(OH)2D3-induced response of various osteoblastic markers in human osteoblastic cells

Age-related bone loss may be a consequence of a lack of osteoblastic formation and/or function. In vitro, the osteoblastic response to 1,25(OH)2D3, an important regulator of osteoblastic function, appears to depend on the stage of osteoblastic maturation. In this study, we examined the response to 1,25(OH)2D3 of C-terminal type I procollagen (PICP), alkaline phosphatase (ALP), and osteocalcin (OC) secretion in primary cultures of osteoblastic cells from human trabecular bone (hOB). Forty-four bone samples were obtained from subjects undergoing knee arthroplastia, 20 aged 50-70 (64 +/- 5), and 24 >70 (73 +/- 2) years. Another 33 bone samples were obtained from subjects undergoing hip arthroplastia, 21 were aged 50-70 (64 +/- 4) and 12 >70 (75 +/- 5) years. Pooling knee and hip hOB cell cultures, we found that PICP secretion decreased after 1,25(OH)2D3 in hOB cells from the older group (>70 years). Treatment with 1,25(OH)2D3 increased ALP secretion in these cells only in the younger group (50-70 years), whereas it increased OC secretion in hOB cells in both age groups. By pooling hOB cell cultures from both age groups we found that knee hOB cells increased OC secretion, and decreased PICP secretion, after 1,25(OH)2D3. This metabolite also increased OC secretion in hip hOB cells. Considering the influence of donor age at the same skeletal site, 1,25(OH)2D3 was found to stimulate ALP secretion only in knee hOB cells in the younger group. In contrast, this metabolite decreased ALP secretion in hip hOB cells in the older group. PICP secretion decreased after 1,25(OH)2D3 only in hOB cells in the older group, at both skeletal sites. In age-matched cultures, OC secretion was lower in hip hOB cells compared with those from the knee in the older group, but was similar in these cell cultures from both skeletal sites in the younger group. OC secretion after 1,25(OH)2D3 stimulation did not show age differences in knee hOB cells, but was lower in hip hOB in the older group. In summary, our results demonstrate that the response of various osteoblastic markers to 1,25(OH)2D3 in primary cultures of hOB cells depends on the donor age and skeletal site of origin.

Effects of age, menopause and osteoporosis on free, peptide-bound and total pyridinium crosslink excretion

We evaluated urinary excretion of free pyridinoline (PYD)-deoxypyridinoline (DPD) by an enzymelinked immunosorbent assay (ELISA) method, free and total PYD by high-performance liquid chromatography (HPLC), free DPD by ELISA, chemiluminiscent immunoassay (CLEIA) and HPLC, total DPD by HPLC, and N-telopeptides (NTX) and C-telopeptides (CTX) by ELISA in 234 women distributed into three groups: 43 healthy young women (aged 26.2 +/- 2.5 years), 56 control postmenopausal women (aged 55.9 +/- 4.5 years) and 133 untreated osteoporotic women (aged 55.1 +/- 4.0 years). The control postmenopausal women had increased values of all markers considered, except NTX, compared with healthy young women. The osteoporotic postmenopausal women had significantly increased values compared with control postmenopausal women for free DPD by HPLC and free DPD by ELISA or CLEIA. HPLC, ELISA and CLEIA showed adequate correlation to measure free PYD and DPD. Control postmenopausal women had significantly decreased values of the fraction of free PYD and DPD (48.4% and 32.0%, respectively), as did the osteoporotic postmenopausal women (48.0% and 46.1%), compared with healthy young women (55.3% and 57.0%). We found a significant negative correlation comparing age with fraction of free PYD and DPD, but a positive correlation with total PYD and DPD, considering or not the osteoporotic postmenopausal women. T-score and Z-score values derived from healthy young women and control postmenopausal women for PYD, DPD, NTX and CTX measured by immunoassays were calculated to detect changes in bone turnover, DPD by ELISA or CLEIA showing the highest Z-score. The sensitivity and specificity of the different assays were evaluated using a receiver operating characteristic (ROC) curve. With a specificity of 90% the sensitivity of the markers considered was low (from 33% for DPD by CLEIA to 11% for PYD-DPD by ELISA), but increased considerably with a specificity of 75%. In conclusion, urinary pyridinium crosslink derivatives increase with age and after the menopause, and rise slightly in women with osteoporosis, there being a negative correlation among age and the fraction of free PYD and DPD of the total urinary excretion. Among the resorption markers most often available in clinical laboratories, free DPD by ELISA or CLEIA was the best at discriminating osteoporotic postmenopausal women from aged-matched control postmenopausal women.

Design and baseline characteristics of study participants in the Wheat Bran Fiber trial

The Wheat Bran Fiber (WBF) trial is a Phase III clinical trial designed to assess the effect of a WBF intervention for 3 years on the recurrence of adenomatous polyps. Men and women, 40-80 years of age, who had removal of one or more colorectal adenoma(s) 3 mm or larger within 3 months prior to study entry were recruited from three sites in the Phoenix metropolitan area. After meeting eligibility criteria, 1509 individuals entered a 6-week run-in period, consisting of a low WBF (2 g/day) intervention. Participants (n = 1429) successfully completed this phase and were randomized to a high (13.5 g/day) or low (2 g/day) WBF intervention. Various data and specimens were collected at baseline and throughout the intervention phase, which included dietary intake, physical activity, other risk factor information, blood specimens, rectal biopsies, and polyp tissues. The study design called for a colonoscopy at approximately 1 year after the qualifying colonoscopy; thus, the period between the first year and the final colonoscopy will be used to assess the effect of the intervention, which is expected to be completed in the latter part of 1998.

Effect of polyethylene on osteocalcin, alkaline phosphatase and procollagen secretion by human osteoblastic cells

We have studied the direct effects of polyethylene particles on osteoblastic function in primary human bone cell cultures. The cells were obtained from trabecular bone fragments of patients undergoing knee reconstructive surgery. When the cells reached confluency, they were subcultured into two flasks, one untreated (control culture) and the other treated with polyethylene particles, and incubated until confluency. Osteoblastic function was evaluated by assaying osteocalcin, alkaline phosphatase, and C-terminal procollagen type I, with and without 1,25(OH)2D stimulation, in the cell-conditioned medium. We found that addition of polyethylene to these osteoblastic cell cultures induced higher levels of secreted osteocalcin after 1, 25(OH)2D stimulation. Alkaline phosphatase levels increased whereas C-terminal procollagen type I levels decreased in the cell conditioned medium after polyethylene was added to the cultures. Treatment of the control cultures with 1,25(OH)2D stimulated alkaline phosphatase levels and decreased C-terminal procollagen type I. However, these osteoblastic markers in 1,25(OH)2D-treated cells did not change in cultures with polyethylene. This study demonstrates that polyethylene particles have a direct effect on osteoblastic markers in human bone cells in culture.

Calcium, vitamin D, and colorectal cancer: a review of the epidemiologic evidence

A protective effect of calcium on colorectal cancer, one of the most common malignancies in Western societies, has been supported primarily by results of in vitro animal studies. The present review summarizes the available epidemiological evidence for the association between calcium, vitamin D, and colorectal cancer. The overall results from over 20 published case-control and cohort studies suggest that calcium intake is not associated with a substantially lower risk of colorectal cancer. Findings from large prospective cohort studies, which should be least affected by methodological bias, have been notably consistent in finding weak and nonsignificant inverse associations. Whereas the relation between calcium and colon or colorectal cancer has been studied in numerous epidemiological studies, the role of vitamin D has only been addressed in a few of these investigations. The available results for vitamin D suggest that this micronutrient is inversely associated with risk but, given the scarcity of data, additional studies are needed to investigate this relation in more detail.

Effect of polyethylene particles on human osteoblastic cell growth

In this study, we have analyzed the direct effect of ultrahigh molecular weight polyethylene (polyethylene) on the osteoblastic cell growth in primary cultures. The cells were cultured from human bone samples obtained during reconstructive joint surgery. When cell cultures reached confluence (4-6 weeks) they were separated into three subcultures. One subculture was without particle addition (plain culture). In the other two subcultures, polyethylene or alumina was added. Two different sizes of particles were used, <80 and <160 microm. The subcultures were incubated until confluence. Proliferation of each subculture was measured by cell counts after 3, 6, 9 and 13 days, and the area under the curve (AUC) was calculated. Polyethylene particles of <160 microm induced a decrease in growth, whereas alumina of the same size did not. Polyethylene and alumina particles of <80 microm induced an inhibition in the osteoblastic cell growth; <80 microm polyethylene induced a higher inhibition than alumina of the same particle size. In conclusion, we have observed a direct effect of polyethylene on osteoblastic cell growth. This study shows that polyethylene may decrease the growth rate of human osteoblastic cells in primary cultures. Smaller particles produce a more marked reduction.

[Effects of bromocriptine in patients with active rheumatoid arthritis]

BACKGROUND

Neuroendocrine factors play an important role in the expression of autoimmune diseases. Prolactin (PRL) can induce T-cell proliferation and macrophage activation. Elevated PRL levels have been described in patients with rheumatoid arthritis (RA).

AIM AND METHODS

We studied immunological and clinical effects of PRL suppression in 9 RA patients with active disease, treated for 3 months with bromocriptine (BRC), an inhibitor of PRL secretion.

RESULTS

BRC induced a significant depression of the peripheral blood mononuclear cells response to antigen (p = 0.008) and mitogen (p = 0.008) which was significantly correlated with improvements in the HAQ disability index (r = 0.68; p = 0.04) and grip strength (r = 0.7; p = 0.02). Also, the in-vitro production of IL-2, nitric oxide and poliamines--that are critical for the proliferative response of lymphoid cells--decreased significantly. The group experienced significant improvement of grip strength (p = 0.028) and the HAQ disability index (p = 0.025), whereas 4 individuals achieved clinical improvement according to the American College of Rheumatology preliminary definition. We conclude that BRC treatment induces a significant depression of in-vitro immune function in RA patients and that these changes are related to parameters of disease activity. The effects of BRC on immune function and disease activity in RA patients warrant further investigation.

Pamidronate and biochemical markers of bone turnover

We have examined the response of different biochemical bone turnover markers to intravenous pamidronate administration (15 mg for 5 days) in 14 patients with Paget's disease, on days 8, 15 and 30 after pamidronate treatment. Urinary parameters of bone resorption, free pyridinolines (Pyr) and hydroxyproline (OHP), as well as serum tartrate-resistant acid phosphatase (TRAP) were measured. Two serum biochemical osteoblastic markers, alkaline phosphatase (AP) and osteocalcin (OC), were also analysed. In addition, ionic calcium (Ca2+) was measured in blood, and parathyroid hormone and calcitriol were measured in serum. All the biochemical markers of bone resorption tested decreased throughout the study. TRAP levels decreased slowly, meanwhile Pyr decreased maximally, below OHP values on day 8. However, the latter were lowest and were lower than those of Pyr on days 15 and 30. AP serum values also decreased during the study. Conversely, OC serum levels increased on days 8 and 15, decreasing to baseline levels on day 30. Ca2+ blood levels decreased while PTH plasma levels increased at all times during the period studied. Calcitriol serum levels increased on day 15. In conclusion, intravenous pamidronate administration was found to modify several biochemical parameters of bone turnover, including Pyr. Moreover, the changes in these parameters were different in intensity and "time course" during the study.

Diet and the prevention of cancer

Cancer ranks as the second-leading cause of death in developed countries and diet has long been suspected as playing a prominent role in its etiology. As a result, a substantial amount of research has been devoted to this field of study. Given the epidemiologic and biologic credibility, it is reasonable to attempt to identify specific nutrients, foods, or combination of these that are causally related to the development of cancer. Various study designs have been employed to generate and test specific hypotheses. In this review, we approach the dietary prevention of cancer primarily from an epidemiologic perspective. We examine the growing body of evidence on dietary etiologic factors and explore the practical prospects for prevention of cancer overall. An attempt is also made to explain inconsistencies in the findings and provide ideas for future research efforts in this field.

A case-control study of dietary intake and other lifestyle risk factors for hyperplastic polyps

BACKGROUND & AIMS

Despite the high prevalence of the hyperplastic polyp, little is known about its etiology. The aim of this study was to assess the relationship between diet and other lifestyle factors and the presence of colorectal hyperplastic polyps.

METHODS

Information on diet and other known or suspected risk factors for colorectal cancer or adenoma was collected among 81 subjects with hyperplastic polyps and 480 controls.

RESULTS

The multivariate-adjusted odds ratio (OR) for hyperplastic polyps for individuals in the upper vs. the lower quartile was 0.30 (95% confidence interval [CI], 0.10-0.88) for dietary fiber, 0.32 (95% CI, 0.11-0.96) for dietary calcium, 0.90 (95% CI, 0.27-2.95) for total fat, and 2.02 (95% CI, 1.05-3.91) for alcohol consumption. Compared with individuals in the lower category, those in the upper category of body mass index had a higher risk for hyperplastic polyps (OR, 4.50; 95% CI, 1.84-10.97). Cigarette smoking was associated with a higher risk (OR, 1.97; 95% CI, 1.02-3.81 for > 20 pack-years vs. never), whereas an inverse association was seen for use of aspirin and other nonsteroidal anti-inflammatory drugs (OR, 0.29; 95% CI, 0.12-0.67 for once per day or more vs. never).

CONCLUSIONS

Hyperplastic polyps share common lifestyle risk factors with colorectal adenomas and carcinomas.

Leisure-time physical activity, body size, and colon cancer in women. Nurses' Health Study Research Group

BACKGROUND

Physical inactivity and high body mass index (weight in kilograms divided by height in square meters) have been linked to increased risk of colon cancer. However, none of the few prospective studies in women has shown a statistically significant reduction in colon cancer incidence or mortality associated with increased leisure-time physical activity.

PURPOSE

In this prospective study, we asked whether leisure-time physical activity, body mass index, or body fat distribution could significantly influence the risk of colon cancer in women.

METHODS

The participants in this study were enrolled in the Nurses' Health Study, which began in 1976. Every 2 years, the women provided additional personal information and information on medical risk factors and major medical events. The time spent per week at a variety of leisure-time physical activities was determined, and the time spent at each activity was multiplied by its typical energy expenditure, expressed in terms of metabolic equivalents or METs. The resulting values for each woman were added to yield an MET-hours-per-week score. Reported diagnoses of colon cancer were confirmed by review of hospital records and pathology reports. Relative risks and associated 95% confidence intervals were calculated.

RESULTS

In multivariate analyses that included body mass index, women who expended more than 21 MET-hours per week on leisure-time physical activity had a relative risk of colon cancer of 0.54 (95% confidence interval [CI] = 0.33-0.90) in comparison with women who expended less than 2 MET-hours per week. Women who had a body mass index greater than 29 kg/m2 had a relative risk of colon cancer of 1.45 (95% CI = 1.02-2.07) in comparison with women who had a body mass index less than 21 kg/m2. A tendency toward higher colon cancer risk was observed for increasing waist-to-hip ratio (relative risk = 1.48 [95% CI = 0.88-2.49] for comparison of the highest quintile ratio [>0.833] to the lowest [<0.728]).

CONCLUSIONS AND IMPLICATIONS

The significant inverse association between leisure-time physical activity and incidence of colon cancer in women in this study is consistent with what has been found in men. Recommendations to increase physical activity and maintain lean body weight should receive greater emphasis as part of a feasible approach to the prevention of colon cancer.

C-terminal parathyroid hormone-related protein inhibits proliferation and differentiation of human osteoblast-like cells

Parathyroid hormone-related protein (PTHrP) is synthesized by osteoblasts, although its local role in bone is not completely understood. The C-terminal (107-111) region of PTHrP seems to be a potent inhibitor of osteoblastic bone resorption. We studied the effect of this PTHrP domain on the proliferation and synthesis of osteoblastic markers in osteoblast-like cells from adult human bone. We found that the human (h)PTHrP(107-139) fragment, between 10 fM and 10 nM, inhibited 3H-thymidine incorporation into these cells. The antiproliferative effect of the latter fragment, or that of hPTHrP(107-111), was similar to that induced by [Tyr34] hPTHrP(1-34) amide, bovine PTH(1-34), and hPTHrP(1-141), while hPTHrP(38-64) amide was ineffective. Human PTHrP(7-34) amide, at 10 nM, and 1 microM phorbol-12-myristate-13-acetate also significantly decreased DNA synthesis in human osteoblast-like cells. Neither hPTHrP(7-34) amide nor hPTHrP(107-139), at 10 nM, stimulated protein kinase A (PKA) activity in these cells. Moreover, 100 nM H-89, a PKA inhibitor, did not eliminate the inhibitory effect of hPTHrP(107-139) on these cells' growth. However 100 nM calphostin C, a PKC inhibitor, blunted this effect of PTHrP(107-139). In addition to their antimitogenic effect, hPTHrP(107-139) and hPTHrP(107-111) inhibited basal and 1,25-dihydroxyvitamin D3 (1,25(OH)2D3)-stimulated alkaline phosphatase activity in these cells. Both fragments, like 1,25(OH)2D3, decreased C-terminal type I procollagen secretion into the cell-conditioned medium, but osteocalcin secretion by these cells was unaffected by the C-terminal PTHrP fragments. These findings suggest that PTHrP may act as a local regulator of bone formation.