Smokeless tobacco (snus) is associated with an increased risk of type 2 diabetes: results from five pooled cohorts.

BACKGROUND: Smoking and nicotine exposure increase insulin resistance and the risk of type 2 diabetes. Swedish smokeless tobacco (snus) is high in nicotine, and its use is prevalent in Scandinavian countries, but few studies have investigated snus use in relation to diabetes risk. OBJECTIVE: To explore the association between snus use and risk of type 2 diabetes using pooled data from five cohorts. METHODS: Analyses were based on prospective studies conducted between 1990 and 2013 including 54 531 never-smoking men and 2441 incident cases of type 2 diabetes identified through screening, self-reporting and hospital and prescription registries. Hazard ratios (HRs) and 95% confidence intervals (CIs) were assessed and adjusted for age, body mass index, educational level, alcohol consumption and physical activity. RESULTS: Compared to never users, the HR of type 2 diabetes was 1.15 (95% CI: 1.00-1.32) in current users of snus. In individuals consuming 5-6 boxes per week, the HR was 1.42 (95% CI: 1.07-1.87); in those consuming ≥7 boxes per week, the HR was 1.68 (95% CI: 1.17-2.41). Each additional box of snus consumed per week yielded an HR of 1.08 (95% CI: 1.01-1.16). CONCLUSION: Our findings indicate that high consumption of snus is a risk factor for type 2 diabetes. The risk was similar to that in smokers, implying that smokers will not reduce their risk of type 2 diabetes by changing to snus use. The results also support the notion that nicotine increases the risk of type 2 diabetes.

How much does the Dallas Pain Questionnaire score have to improve to indicate that patients with chronic low back pain feel better or well?

PURPOSE: The Dallas Pain Questionnaire (DPQ) assesses the impact of low back pain (LBP) on four components (0-100) of daily life. We estimated the minimal clinically important improvement (MCII) and the patient acceptable symptom state (PASS) values of DPQ in LBP patients. METHODS: 142 patients with LBP lasting for at least 4 weeks completed a battery of questionnaires at baseline and 6 months later. Questions for MCII addressed patient-reported response to treatment at 6 months on a five-point Likert scale, while a yes/no question concerning satisfaction with present state was used to determine PASS. MCII was computed as the difference in mean DPQ scores between patients reporting treatment as effective vs. patients reporting treatment as not effective, and PASS was computed as the third quartile of the DPQ score among patients who reported being satisfied with their present state. RESULTS: MCII values were 22, 23, 2 and 10 for daily activities, work and leisure, social interest, and anxiety/depression, respectively. PASS values were 29, 23, 20 and 21 for the four components, respectively. The PASS total score threshold of 24 correctly classified 84.1 % of the patients who reported being unsatisfied with their present state, and 74.7 % of patients reported being satisfied. CONCLUSIONS: These values give information of paramount importance for clinicians in interpreting change in DPQ values over time. Authors should be encouraged to report the percentage of patients who reach MCII and PASS values in randomized clinical trials and cohort studies to help clinicians to interpret clinical results.

Core Outcome Measure Index for low back patients: do we miss anxiety and depression?

PURPOSE: The Core Outcome Measure Index (COMI) is a multidimensional questionnaire that investigates five dimensions in low back pain (LBP) patients, but does not address the psychological dimension. As the biopsychosocial perspective is recognized as important to capture the entire clinical picture of these patients, this multicenter prospective cohort study was designed to investigate the psychometric properties of a modified version of the COMI (COMIAD) which included 2 additional items, exploring anxiety and depression, respectively. METHODS: 168 subacute or chronic LBP patients recruited in spine clinics completed a set of questionnaires before and after treatment (follow-up at 6 months). Construct validity was explored by comparing each item of the COMIAD to validated full-length questionnaires. Thus two additional questionnaires were included to assess the construct validity of the anxiety and depression measures. The psychometric properties of the COMI and COMIAD were then compared. RESULTS: The two new items showed good internal consistency, high correlations with the corresponding full-length questionnaires, no floor or ceiling effect and good reproducibility (test-retest agreement kappa 0.68 for anxiety, 0.62 for depression). The addition of the 2 items did not alter internal validity (Cronbach's alpha = 0.88 and 0.87, respectively). The smallest detectable difference, the Minimal Clinically Important Improvement and the Patient Acceptable Symptom State were only minimally affected by the changes. CONCLUSION: The questions exploring anxiety and depression have good intrinsic and psychometric capacities (i.e., no floor or ceiling effects and high correlations with full-length scales) and did not significantly modify the psychometrics of the original COMI questionnaire. The COMIAD offers the possibility to include the psychological dimension in the multidimensional evaluation without significantly affecting questionnaire length.

Healthy behaviours and 10-year incidence of diabetes: a population cohort study.

OBJECTIVE: To examine the association between meeting behavioural goals and diabetes incidence over 10 years in a large, representative Swedish population. METHODS: Population-based prospective cohort study of 32,120 individuals aged 35 to 55 years participating in a health promotion intervention in Västerbotten County, Sweden (1990 to 2013). Participants underwent an oral glucose tolerance test, clinical measures, and completed diet and activity questionnaires. Poisson regression quantified the association between achieving six behavioural goals at baseline - body mass index (BMI) <25 kg/m(2), moderate physical activity, non-smoker, fat intake <30% of energy, fibre intake ≥15 g/4184 kJ and alcohol intake ≤20 g/day - and diabetes incidence over 10 years. RESULTS: Median interquartile range (IQR) follow-up time was 9.9 (0.3) years; 2211 individuals (7%) developed diabetes. Only 4.4% of participants met all 6 goals (n=1245) and compared to these individuals, participants meeting 0/1 goals had a 3.74 times higher diabetes incidence (95% confidence interval (CI)=2.50 to 5.59), adjusting for sex, age, calendar period, education, family history of diabetes, history of myocardial infarction and long-term illness. If everyone achieved at least four behavioural goals, 14.1% (95% CI: 11.7 to 16.5%) of incident diabetes cases might be avoided. CONCLUSION: Interventions promoting the achievement of behavioural goals in the general population could significantly reduce diabetes incidence.

[Cross-cultural validation of the Oswestry disability index in French]. / Validation transculturelle de l'Oswestry disability index en français.

AIM: The aim of this study was to interpret and validate a French version of the Oswestry disability index (ODI), using a cross-cultural validation method. The validity and reliability of the questionnaire was assessed in order to ensure the psychometric characteristics. METHOD: The cross-cultural validation was carried out according to Beaton's methodology. The study was conducted with 41 patients suffering from low back pain. The correlation between the ODI and the Roland-Morris disability questionnaire (RMDQ), the medical outcome survey short form-36 (MOS SF-36) and a pain visual analogical scale (VAS) was assessed. RESULTS: The validity of the Oswestry questionnaire was studied using the Cronbach Alpha coefficient calculation: 0.87 (n=36). The significant correlation between the ODI and RMDQ was 0.8 (P<0.001, n=41) and 0.71 (P<0.001, n=36) for the pain VAS. The correlation between the ODI and certain subscales (physical functioning 0.7 (P<0.001, n=41), physical role 0.49 et bodily pain 0.73 (P<0.001, n=41)) of the MOS SF-36 were equally significant. The reproducibility of the ODI was calculated using the Wilcoxon matched pairs test: there was no significant difference for eight out of ten sections or for the final score. CONCLUSION: This French translation of the ODI should be considered as valid and reliable. It should be used for any future clinical studies carried out using French language patients. Complimentary studies must be completed in order to assess its sensitivity to change in the event of any modifications in the patients functional capacity.

Work stress and low emotional support is associated with increased risk of future type 2 diabetes in women.

A case-referent study nested within a population-based health survey investigated the associations between psychosocial stress, such as work stress and low emotional support, and future development of type 2 diabetes among occupationally working middle-aged men and women. All participants in a health survey conducted during 1989-2000 (n=33,336) in Umeå in northern Sweden, were included. We identified 191 cases, who were not diabetic initially but were diagnosed with type 2 diabetes after 5.4+/-2.6 years. Two age- and sex-matched referents were selected for each case. Multivariate logistic regression analyses and interaction effects between variables were evaluated. In women, passive or tense working situations were associated with future type 2 diabetes with odds ratios 3.6 (95% confidence interval 1.1-11.7) and 3.6 (1.0-13.3), respectively, and also low emotional support 3.0 (1.3-7.0). These associations were not seen in men. In women, they remained after adjustment for BMI, civil status and educational level, and there were also tendencies for interactions between work stress and low emotional support. In conclusion, work stress and low emotional support may increase the risk of type 2 diabetes in women, but not in men. These findings contribute to our understanding of psychosocial stress as potential risk factors for type 2 diabetes in a Swedish population.

Tobacco use is not associated with groin hernia repair, a population-based study.

PURPOSE: The pathogenesis of groin hernia is not fully understood and some suggested risk factors are debatable. This population-based study evaluates the association between groin hernia repair and tobacco use. METHOD: An observational study based on register linkage between the Swedish Hernia Register and the Västerbotten Intervention Program (VIP). All primary groin hernia repairs performed from 2001 to 2013 in the county of Västerbotten, Sweden, were included. RESULTS: VIP provided data on the use of tobacco in 102,857 individuals. Neither smoking nor the use of snus, increased the risk for requiring a groin hernia repair. On the contrary, heavy smoking decreased the risk for men, HR 0.75 (95% CI 0.58-0.96), as did having a BMI over 30 kg/m2 HR (men) 0.33 (95% CI 0.27-0.40). CONCLUSION: Tobacco use is not a risk factor for requiring a groin hernia repair, whereas having a low BMI significantly increases the risk.

Factors leading to rehospitalization for tracheostomized and ventilator-dependent infants through 2 years of age.

OBJECTIVE: To identify factors leading to readmission for tracheostomized, ventilator-dependent infants <2 years of age. STUDY DESIGN: Retrospective cohort study of 117 tracheostomized, ventilator-dependent infants followed through 2 years of age. RESULTS: Home ventilator use (at hospital discharge, 6 and 12 months of age), inhaled steroid use (at 12 and 24 months of age), oxygen dependence (at 6 and 12 months of age) and tracheostomy (at discharge, 6 and 12 months of age) were increased risks for rehospitalization. Equipment malfunction throughout the first 2 years also contributed to readmissions. Viral infection, with rhinovirus/enterovirus the most commonly identified pathogen, was the most common etiology for rehospitalization. Diuretic use and initial comorbid diagnoses were not associated with increased risk of rehospitalization. CONCLUSION: The risk for rehospitalization for infants requiring tracheostomy and ventilator support was affected by prolonged oxygen use, prolonged ventilator dependence, inhaled steroid use and equipment malfunction, and was equally distributed throughout the first 2 years of life.

A comparison of 7-day versus 10-day course of low-dose dexamethasone for chronically ventilated preterm infants.

OBJECTIVE: The objective of the study was to compare the effect of two different dexamethasone regimens on respiratory outcomes of ventilator-dependent preterm infants. STUDY DESIGN: Retrospective study of ventilated preterm infants <29 weeks gestational age treated with either 7-day or 10-day dexamethasone course. Primary outcome was days to successful extubation. Other outcomes included rate of successful extubation and need for repeat steroid therapy. RESULTS: Fifty-nine infants were identified; 32 (54%) received 7 days of dexamethasone and 27 (46%) received 10 days of dexamethasone. Both groups had comparable baseline demographics and clinical characteristics. Mean time to successful extubation was similar between the two groups (5.1±2.7 days in 7-day group and 6.0±3.7 days in 10-day group, P=0.42). Successful extubation by end of treatment (56% versus 67%, P=0.44) and need for repeat steroid therapy (47% versus 33%, P=0.43) were also similar. CONCLUSION: 7-day and 10-day course of dexamethasone have comparable efficacy in facilitating extubation of ventilator-dependent preterm infants.

Prevalence of vitamin D deficiency and its association with nutrition, travelling and clothing habits in an immigrant population in Northern Sweden.

OBJECTIVES: To study prevalence and determinants of vitamin D deficiency in immigrants from Africa and the Middle East living in Umeå, Sweden. DESIGN: Cross-sectional population based. SETTING: Umeå, Sweden (63° N). SUBJECTS/METHODS: Immigrants aged 25-65 years from nine countries in Africa or the Middle East (n=1306) were invited. A total of 111 men and 106 women (16.5%) completed the study. S-25-hydroxyvitamin D3 was measured with HPLC. Anthropometry, medical, socioeconomic and lifestyle data were registered. RESULTS: Vitamin D status was insufficient or deficient in 73% of the participants. Specifically, 12% had vitamin D deficiency (25(OH)D3<25 nmol/l), and only 3.7% had optimal vitamin D status (25(OH)D3 75-125 nmol/l). Mean 25(OH)D3 level was 41.0 nmol/l (± 16.6) with no difference between sexes. Levels of 25(OH)D3 were lower (P=0.030) and vitamin D deficiency was twice as common in immigrants from Africa compared with those from the Middle East. In the multiple regression analysis, vitamin D deficiency was significantly associated with low fatty fish intake (OR 4.31, 95% CI 1.61-11.55), not travelling abroad (OR 3.76, 95% CI 1.18-11.96) and wearing long-sleeved clothes in summer (OR 3.15, 95% CI 1.09-9.12). CONCLUSIONS: The majority of immigrants from Africa and the Middle East who live in northern Sweden have vitamin D deficiency or insufficiency. Our results are consistent with sun exposure and a diet with high intake of fatty fish being most important in avoiding vitamin D deficiency.

Reduced phagosomal content of the retinal pigment epithelium in response to retinoid deprivation.

Previous investigations have shown that lipofuscin accumulation in the retinal pigment epithelium (RPE) is reduced greatly as a consequence of vitamin A deprivation. The mechanism by which vitamin A regulates RPE lipofuscin deposition remains to be determined. It is possible that retinoids are direct precursors of this substance. Alternatively, vitamin A deficiency may reduce the uptake and processing of other potential precursors. In retinas lacking photoreceptor cells, RPE lipofuscin accumulation is decreased substantially. This finding suggested that components of phagocytosed photoreceptor outer segments may be precursors for RPE lipofuscin. The effect of vitamin A deprivation on RPE lipofuscin content therefore could be the result of reduced outer segment phagocytosis by the RPE of vitamin A-deprived animals. To evaluate this possibility, experiments were conducted to determine whether vitamin A deprivation altered the phagosomal content of the RPE. Rats were fed diets containing or lacking retinoid precursors of 11-cis retinal. Retinoic acid was included in the diets of the vitamin A-deprived animals. After both 10 and 26 weeks, the RPE phagosomal contents were determined in animals from each dietary group. Photoreceptor cell densities also were measured in these rats. At both time points, the RPE phagosomal content was lower significantly in the retinoid-deprived animals than in those fed a vitamin A precursor of the visual pigment chromophore. This reduction was not the result of photoreceptor cell death; the density of these cells was not affected significantly by dietary vitamin A. Thus, it appears that retinoid deprivation reduces the rate of photoreceptor outer segment turnover and, consequently, outer segment phagocytosis by the RPE.(ABSTRACT TRUNCATED AT 250 WORDS)

Bright environmental light accelerates rhodopsin depletion in retinoid-deprived rats.

PURPOSE: Dietary deficiency in the retinoid precursors of the visual pigment chromophore 11-cis retinal eventually results in selective degeneration of the photoreceptor cells of the vertebrate retina. An early effect of retinoid deficiency is depletion of chromophore from the photoreceptor outer segments. Experiments were conducted to determine whether the rate of chromophore depletion was affected by the intensity of environmental light. METHODS: Rats were maintained on diets either containing or lacking retinoid precursors of 11-cis retinal for up to 30 weeks. Animals in both dietary groups were exposed to either bright (90 lux) or dim (5 lux) cyclic light for the duration of the experiment. At various time intervals retinal rhodopsin content and photoreceptor densities were determined in animals from each treatment group. RESULTS: Bright light greatly accelerated the depletion of rhodopsin from the retina. Rhodopsin was almost completely depleted from the retinas of the retinoid-deficient animals raised under bright light for 25 weeks, whereas the dim-light-reared animals fed the retinoid-deficient diet still had significant amounts of retinal rhodopsin even after 30 weeks. Bright light alone moderately depressed retinal rhodopsin levels in animals fed the diet containing a vitamin A precursor of 11-cis retinal. Among rats fed the latter diet, retinal rhodopsin content in the animals kept in bright cyclic light was maintained throughout the experiment at about 70% of the amount of rhodopsin in rats housed in dim cyclic light. The light-related rhodopsin depletion in the retinoid-deprived rats was accompanied by photoreceptor cell death. After 30 weeks of treatment, photoreceptor cell densities remained similar in all treatment groups except the retinoid-deprived group housed under bright cyclic light. In the latter group, photoreceptor cell densities in the central retinas were reduced by an average of more than 50% after 30 weeks. Retinoid deficiency and bright light exposure alone each resulted in a reduction in rod outer segment size. An even greater reduction in outer segment size was observed in vitamin A-deprived animals housed under bright cyclic light. CONCLUSION: These findings indicate that light accelerates the depletion of retinoids from the retina and the accompanying photoreceptor cell degeneration.

Stimulation of cell division by argon and Nd:YAG laser trabeculoplasty in cynomolgus monkeys.

Although laser treatment of the trabecular meshwork is the most common form of surgery for glaucoma, the tissue response to this therapy is still incompletely understood. We applied argon or Nd:YAG laser to the trabecular meshwork of six monkeys. Cell division was identified by injecting tritiated thymidine into the anterior chamber 24 hr after laser application. Autoradiography of tissue sections revealed significantly more labelled cells in eyes treated with laser than in the untreated controls. In addition, cells in neighboring tissues such as iris, ciliary body and sclera showed labelling in association with laser application. Furthermore, comparison of argon-induced lesions with those caused by pulsed Nd:YAG suggests that there are quantitative and qualitative differences in the response of trabecular meshwork and surrounding tissues to these two forms of laser energy.

Maintenance of opsin density in photoreceptor outer segments of retinoid-deprived rats.

Dietary deficiency in the retinoid precursors of the visual pigment chromophore 11-cis-retinal eventually results in selective degeneration of the photoreceptor cells of the vertebrate retina. Early effects of retinoid deficiency are depletion of rhodopsin from the retina and vesiculation of the photoreceptor outer segment disc membranes. Experiments were conducted to determine whether these early changes were accompanied by an alteration of the opsin content of the disc membranes. After being fed a retinoid-deficient diet containing retinoic acid for 26 weeks, the rhodopsin content of rat retinas was reduced by over 85%. Both the diameters and the lengths of the outer segments decreased significantly. However, immunocytochemical and freeze-fracture analyses indicated that retinoid deficiency did not lower opsin density in the outer-segment disc membranes. These findings indicate that in the rat, opsin synthesis and disc assembly are coordinated processes that remain coupled despite reduced availability of the vitamin A chromophore. The fact that disc size decreases and disc synthesis eventually ceases in retinoid-deprived rats indicates that specific retinoids are essential for disc morphogenesis. The mechanism by which these retinoids regulate disc assembly remains to be determined.

Preoperative histological and cytological diagnosis and DNA ploidy assessment of localized prostatic cancer. A comparison between findings in biopsies and total prostatectomy specimens.

The preoperative biopsy specimens of 49 men who underwent radical prostatectomy were compared with serially step-sectioned operative specimens, in order to evaluate diagnostic accuracy as regards the presence of cancer, its grade and its DNA ploidy. Both the FNAB and TRUS-GCB undergraded the cancer by one WHO grade in about 35-40% of cases. In cases where both biopsy types were available, the degree of undergrading was the same. Determination of DNA ploidy by the single-cell technique from FNAB had a sensitivity for detecting non-diploid DNA patterns of 59% whereas flow cytometric measurement of core biopsies had a sensitivity of 44.4% as regards non-diploid DNA, when compared with operative specimens. A comparison of ploidy in core biopsies versus ploidy in fine-needle aspirates revealed that more non-diploid DNA patterns were diagnosed in the fine-needle aspirates. These aneuploid patterns were not all confirmed by flow cytometric evaluation of the operative specimens, in which, however, more aneuploid patterns were diagnosed compared with the single-cell technique from FNAB. We conclude that the standard technique with 1-3 fine-needle aspirates or 1-3 TRUS-GCB has a pronounced tendency by both biopsy methods to underestimate the tumour grade. DNA ploidy analysis by FNAB and the single-cell cytometric method reveals aneuploid cell lines not found in the flow cytometric evaluation. In order to determine whether this reflects a methodological problem or a true discrimination between the ability of the two methods to find non-diploid cell lines further studies are needed. However, for a more correct preoperative assessment of tumour grade and DNA ploidy, more extensive sampling is required.

Estimation of prostate cancer volume by multiple core biopsies before radical prostatectomy.

OBJECTIVES: To investigate whether tumor volume, an important prognostic factor in prostate cancer, could be estimated from the amount of cancer in multiple core biopsies. METHODS: In 80 men, transrectal ultrasound-guided biopsies were taken from focal lesions detected by ultrasound and 8 to 10 standardized positions, including sextant biopsies (apex, midmedial, base) and midlateral and transition zone biopsies. The cancer length in the biopsies was measured. After radical prostatectomy, the prostates were totally embedded, whole-mounted, and tumor volume was measured planimetrically. RESULTS: The tumor volume correlated significantly with the total cancer length of all biopsies (r = 0.56) and of the sextant biopsies (r = 0.39). It was found that midlateral and transition zone biopsies provided independent information when included in a multiple regression model with tumor volume as the dependent variable and the sextant biopsies as explanatory variables. All men (n = 6) with less than 3 mm cancer length in only one positive biopsy and a Gleason score less than 7 had a tumor volume less than 1 mL. Nine of 10 men with less than 7 mm of cancer in one positive biopsy and Gleason score less than 7 had tumors smaller than 1 mL. Sextant biopsies did not reliably predict cancer volumes less than 1 mL. CONCLUSIONS: The cancer yield of 8 to 10 biopsies correlated better with the volume of prostate cancer than sextant biopsies. This extended biopsy protocol could be used to predict cancers of less than 1 mL in volume.

Three-dimensional computer reconstruction of prostate cancer from radical prostatectomy specimens: evaluation of the model by core biopsy simulation.

OBJECTIVES: A technique was developed for three-dimensional (3D) modeling of prostate cancer and transrectal biopsies. To test the model, the cancer yield of a simulated 10-biopsy protocol was compared with a simulated sextant protocol and with preoperative biopsies regarding cancer detection and correlation with tumor volume. METHODS: Transrectal ultrasound-guided core biopsies were taken from 81 men according to a standardized 10-biopsy protocol that included sextant biopsies. The patients underwent radical prostatectomy and specimens were step-sectioned and whole-mounted. Cancer and the prostate capsule were outlined on the slides and the regions transferred to a computer software program developed by our group. A 3D volume of each prostate was reconstructed from the sections. Virtual core biopsy needles imitating the positions of the real biopsies were inserted into the prostate and the cancer yield was calculated. Only the standardized positions were considered in this study (ie, additional biopsies from hypoechoic foci were not accounted for). RESULTS: Of the cancers detected with 10 standardized virtual biopsies, 24% would have remained undetected with sextant biopsies. The cancer yield of 10 virtual biopsies correlated with the preoperative biopsies (r = 0.64) and with the tumor volume (r = 0.56). A multiple regression analysis showed that the cancer yield of a simulation of 10 biopsies correlated better with tumor volume than did a simulation of sextant biopsies (P = 0.02). CONCLUSIONS: We conclude that computer-assisted 3D reconstruction of prostate cancer can be used as a model for evaluation and optimization of biopsy protocols.

The sextant protocol for ultrasound-guided core biopsies of the prostate underestimates the presence of cancer.

OBJECTIVES: The aim of this prospective study was to evaluate the sensitivity of the sextant biopsy protocol compared with a more extensive procedure for the detection of prostate cancer and to define a biopsy model with the minimal number of biopsies necessary to maintain diagnostic accuracy. METHODS: A total of 512 consecutive patients with suspected prostate cancer were examined with transrectal ultrasound (TRUS) and underwent TRUS-guided core biopsy. All patients had 8 or 10 standardized biopsy samples taken, with the number depending on the size of the gland. Additional biopsy samples were taken from hypoechoic or hyperechoic lesions located outside the predetermined location for the standardized biopsies (ie, target biopsies). The sensitivity of the detection of cancer for different combinations of biopsy samples was analyzed and compared with that of our model with 8 to 10 biopsies. RESULTS: In all, 276 cancers were detected, of which 88 (32%) had an isoechoic appearance. Sensitivity was 59% for focal lesions detected by TRUS, 85% to 97% for different combinations of systematic biopsy samples, and 93% to 98% for a combination of systematic and target biopsy samples. The sensitivity for the standard sextant protocol was 85%. By adding target biopsies, the sensitivity increased to 93%. CONCLUSIONS: The standard sextant protocol leaves 15% of cancers undetected compared with results obtained from a more extensive biopsy procedure. By combining systematic and target sampling, the sensitivity increases; however, a major concern is that the clinical importance of cancers detected by multiple biopsies needs to be evaluated.

Three-dimensional modeling of biopsy protocols for localized prostate cancer.

Prostate cancer is the most common malignant tumor in American men, yet only a small percentage of men will develop clinically significant disease. Needle core biopsies are used to confirm the presence of cancer prior to surgery. While needle core biopsies have shown some ability to predict tumor volume and grade in prostatectomy specimens, for the individual patient they are neither sensitive nor specific enough to guide therapy. In this paper, we describe a system for simulating needle biopsies on three-dimensional models of cancerous prostates reconstructed from serial sections. First we segment the serial sections, delineating tumors and landmarks. Next, we register the sections using a color-merging scheme, and reconstruct the three-dimensional model using modified-shape-based interpolation. The resulting volume can be rendered, and simulated needle core biopsies can be taken from the reconstructed model. We use our system to simulate two different biopsy protocols on a reconstructed prostate specimen.

Imaging in the diagnosis and assessment of prognosis in localized prostate cancer. Consensus Conference on Diagnosis and Prognostic Parameters in Localized Prostate Cancer. Stockholm, Sweden, May 12-13, 1993.

As part of a WHO consensus conference on diagnosis and prognostic parameters in localized prostate cancer, a working group of experts discussed the role of various modern imaging techniques. Special attention was focused on transrectal ultrasound (TRUS) in combination with biopsies, magnetic resonance imaging (MRI) using endorectal coil and recent advances in these techniques. Some experimental techniques, especially hormone receptor scintigraphy and positron emission tomography were also discussed and new results were presented. We concluded that MRI seems to be superior to other imaging techniques in the preoperative assessment of local tumor stage. TRUS defends its place in the diagnostic armament; it is easily combined with multiple biopsies, the results of which are important in the assessment of the biological aggressiveness of prostate cancer. The present development in the field of nuclear medicine may result in techniques for in vivo characterization of tumors and will most certainly have important implications for diagnosis of prostate cancer in the future.