Fiber and whole grain intakes in relation to liver cancer risk: An analysis in 2 prospective cohorts and systematic review and meta-analysis of prospective studies

BACKGROUND AND AIMS

The association between fiber or whole grain intakes and the risk of liver cancer remains unclear. We assessed the associations between fiber or whole grain intakes and liver cancer risk among 2 prospective studies, and systematically reviewed and meta-analyzed these results with published prospective studies.

APPROACH AND RESULTS

A total of 111,396 participants from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) and 26,085 men from the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study were included. Intakes of total fiber and whole grains were estimated from validated food frequency questionnaires. Study-specific HRs and 95% CI with liver cancer risk were estimated using multivariable-adjusted Cox regression. We systematically reviewed existing literature, and studies were combined in a dose-response meta-analysis. A total of 277 (median follow-up = 15.6 y) and 165 (median follow-up = 16.0 y) cases of liver cancer were observed in Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial and Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, respectively. Dietary fiber was inversely associated with liver cancer risk in Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (HR 10g/day : 0.69; 95% CI: 0.55-0.86). No significant associations were observed between whole grain intakes and liver cancer risk in either study. Our meta-analysis included 2383 incident liver cancer cases (7 prospective cohorts) for fiber intake and 1523 cases (5 prospective cohorts) for whole grain intake; combined HRs for liver cancer risk were 0.83 (0.76-0.91) per 10 g/day of fiber and 0.92 (0.85-0.99) per 16 g/day (1 serving) of whole grains.

CONCLUSIONS

Dietary fiber and whole grains were inversely associated with liver cancer risk. Further research exploring potential mechanisms and different fiber types is needed.

Surgical approach to a rare case of Beckwith Wiedemann syndrome with left thigh hyperplasia

Thigh lift surgery is generally performed in patients with severe weight loss outcomes, particularly those undergoing bariatric surgery. However, there are other congenital malformation conditions that may require the same treatment, such as Beckwith Wideman syndrome.

Helicobacter hepaticus and Helicobacter bilis in liver and biliary cancers from ATBC and PLCO

BACKGROUND

Helicobacter species (spp.) have been detected in human bile and hepatobiliary tissue Helicobacter spp. promote gallstone formation and hepatobiliary tumors in laboratory studies, though it remains unclear whether Helicobacter spp. contribute to these cancers in humans. We used a multiplex panel to assess whether seropositivity to Helicobacter (H.) hepaticus or H. bilis proteins was associated with the development of hepatobiliary cancers in the Finnish Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, and US-based Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO).

METHODS

We included 62 biliary and 121 liver cancers, and 190 age-matched controls from ATBC and 74 biliary and 105 liver cancers, and 364 age- and sex-matched controls from PLCO. Seropositivity to 14 H. hepaticus and H. bilis antigens was measured using a multiplex assay. Odds ratios (ORs) and 95% confidence intervals (CIs) were adjusted for major hepatobiliary cancer risk factors and Helicobacter pylori serostatus.

RESULTS

Seropositivity to the H. bilis antigen, P167D, was associated with more than a twofold higher risk of liver cancer (OR: 2.38; 95% CI: 1.06, 5.36) and seropositivity to the H. hepaticus antigens HH0407 or HH1201, or H. bilis antigen, HRAG 01470 were associated with higher risk of biliary cancer (OR: 5.01; 95% CI: 1.53, 16.40; OR: 2.40; 95% CI: 1.00, 5.76; OR: 3.27; 95% CI: 1.14, 9.34, respectively) within PLCO. No associations for any of the H. hepaticus or H. bilis antigens were noted for liver or biliary cancers within ATBC.

CONCLUSIONS

Further investigations in cohort studies should examine the role of Helicobacter spp. in the etiology of liver and biliary cancers.

Yoghurt Intake and Gastric Cancer: A Pooled Analysis of 16 Studies of the StoP Consortium

BACKGROUND

Yoghurt can modify gastrointestinal disease risk, possibly acting on gut microbiota. Our study aimed at exploring the under-investigated association between yoghurt and gastric cancer (GC).

METHODS

We pooled data from 16 studies from the Stomach Cancer Pooling (StoP) Project. Total yoghurt intake was derived from food frequency questionnaires. We calculated study-specific odds ratios (ORs) of GC and the corresponding 95% confidence intervals (CIs) for increasing categories of yoghurt consumption using univariate and multivariable unconditional logistic regression models. A two-stage analysis, with a meta-analysis of the pooled adjusted data, was conducted.

RESULTS

The analysis included 6278 GC cases and 14,181 controls, including 1179 cardia and 3463 non-cardia, 1191 diffuse and 1717 intestinal cases. The overall meta-analysis revealed no association between increasing portions of yoghurt intake (continuous) and GC (OR = 0.98, 95% CI = 0.94-1.02). When restricting to cohort studies, a borderline inverse relationship was found (OR = 0.93, 95% CI = 0.88-0.99). The adjusted and unadjusted OR were 0.92 (95% CI = 0.85-0.99) and 0.78 (95% CI = 0.73-0.84) for any vs. no yoghurt consumption and GC risk. The OR for 1 category of increase in yoghurt intake was 0.96 (95% CI = 0.91-1.02) for cardia, 1.03 (95% CI = 1.00-1.07) for non-cardia, 1.12 (95% CI = 1.07-1.19) for diffuse and 1.02 (95% CI = 0.97-1.06) for intestinal GC. No effect was seen within hospital-based and population-based studies, nor in men or women.

CONCLUSIONS

We found no association between yoghurt and GC in the main adjusted models, despite sensitivity analyses suggesting a protective effect. Additional studies should further address this association.

Serum metabolomic profile of hair dye use

The International Agency for Research on Cancer reported that some chemicals in hair dyes are probably carcinogenic to those exposed to them occupationally. Biological mechanisms through which hair dye use may be related to human metabolism and cancer risk are not well-established. We conducted the first serum metabolomic examination comparing hair dye users and nonusers in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. Metabolite assays were conducted using ultrahigh performance liquid chromatography-tandem mass spectrometry. The association between metabolite levels and hair dye use was estimated using linear regression, adjusting for age, body mass index, smoking, and multiple comparisons. Among the 1,401 detected metabolites, 11 compounds differed significantly between the two groups, including four amino acids and three xenobiotics. Redox-related glutathione metabolism was heavily represented, with L-cysteinylglycine disulfide showing the strongest association with hair dye (effect size (β) =  -  0.263; FDR adjusted p-value = 0.0311), along with cysteineglutathione disulfide (β =  - 0.685; FDR adjusted p-value = 0.0312). 5alpha-Androstan-3alpha,17beta-diol disulfate was reduced in hair dye users (β =  - 0.492; FDR adjusted p-value = 0.077). Several compounds related to antioxidation/ROS and other pathways differed significantly between hair dye users and nonusers, including metabolites previously associated with prostate cancer. Our findings suggest possible biological mechanisms through which the use of hair dye could be associated with human metabolism and cancer risk.

Enterohepatic Shunt-Driven Cholemia Predisposes to Liver Cancer

BACKGROUND & AIMS

Pathogenesis of hepatocellular carcinoma (HCC), which kills millions annually, is poorly understood. Identification of risk factors and modifiable determinants and mechanistic understanding of how they impact HCC are urgently needed.

METHODS

We sought early prognostic indicators of HCC in C57BL/6 mice, which we found were prone to developing this disease when fed a fermentable fiber-enriched diet. Such markers were used to phenotype and interrogate stages of HCC development. Their human relevance was tested using serum collected prospectively from an HCC/case-control cohort.

RESULTS

HCC proneness in mice was dictated by the presence of congenitally present portosystemic shunt (PSS), which resulted in markedly elevated serum bile acids (BAs). Approximately 10% of mice from various sources exhibited PSS/cholemia, but lacked an overt phenotype when fed standard chow. However, PSS/cholemic mice fed compositionally defined diets, developed BA- and cyclooxygenase-dependent liver injury, which was exacerbated and uniformly progressed to HCC when diets were enriched with the fermentable fiber inulin. Such progression to cholestatic HCC associated with exacerbated cholemia and an immunosuppressive milieu, both of which were required in that HCC was prevented by impeding BA biosynthesis or neutralizing interleukin-10 or programmed death protein 1. Analysis of human sera revealed that elevated BA was associated with future development of HCC.

CONCLUSIONS

PSS is relatively common in C57BL/6 mice and causes silent cholemia, which predisposes to liver injury and HCC, particularly when fed a fermentable fiber-enriched diet. Incidence of silent PSS/cholemia in humans awaits investigation. Regardless, measuring serum BA may aid HCC risk assessment, potentially alerting select individuals to consider dietary or BA interventions.

Racial/ethnic disparities in hepatocellular carcinoma incidence and mortality rates in the United States, 1992-2018

BACKGROUND AND AIMS

HCC is characterized by racial/ethnic disparities in rates. Recent USA reports suggest that incidence has begun to decline, but it is not clear whether the declines have occurred among all groups, nor whether mortality has declined. Thus, the current study examined USA incidence and mortality between 1992 and 2018.

APPROACH & RESULTS

HCC incidence and incidence-based mortality data from the Surveillance, Epidemiology, and End Results program were used to calculate age-standardized rates by race/ethnicity, sex, and age. Trends were analyzed using joinpoint regression to estimate annual percent change (APC). Age-period-cohort models assessed the effects on trends of age, calendar period, and birth cohort. Overall, HCC incidence significantly declined between 2015 and 2018 (APC, -5.6%). Whereas most groups experienced incidence declines, the trends were most evident among Asians/Pacific Islanders, women, and persons <50 years old. Exceptions were the rates among non-Hispanic Black persons, which did not significantly decline (APC, -0.7), and among American Indians/Alaska Natives, which significantly increased (APC, +4.3%). Age-period-cohort modeling found that birth cohort had a greater effect on rates than calendar period. Among the baby boom cohorts, the 1950-1954 cohort had the highest rates. Similar to the overall incidence decline, HCC mortality rates declined between 2013 and 2018 (APC, -2.2%).

CONCLUSIONS

HCC incidence and mortality rates began to decline for most groups in 2015, but persistent differences in rates continued to exist. Rates among non-Hispanic Black persons did not decline significantly, and rates among American Indians/Alaska Natives significantly increased, suggesting that greater effort is needed to reduce the HCC burden among these vulnerable groups.

Circulating bile acid concentrations and non-alcoholic fatty liver disease in Guatemala

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a major liver disease worldwide. Bile acid dysregulation may be a key feature in its pathogenesis and progression.

AIMS

To characterise the relationship between bile acid levels and NAFLD at the population level METHODS: We conducted a cross-sectional study in Guatemala in 2016 to examine the prevalence of NAFLD. Participants (n = 415) completed questionnaires, donated blood samples and had a brief medical exam. NAFLD was determined by calculation of the fatty liver index. The levels of 15 circulating bile acids were determined by LC-MS/MS. Adjusted prevalence odds ratios (POR_adj ) and 95% CI were calculated to examine the relationships between bile acid levels (in tertiles) and NAFLD.

RESULTS

Persons with NAFLD had significantly higher levels of the conjugated primary bile acids glycocholic acid (GCA) (POR_{adj T3 vs T1}  = 1.85), taurocholic acid (TCA) (POR_{adj T3 vs T1}  = 2.45) and taurochenodeoxycholic acid (TCDCA) (POR_{adj T3 vs T1}  = 2.10), as well as significantly higher levels the unconjugated secondary bile acid, deoxycholic acid (DCA) (POR_{adj T3 vs T1}  = 1.78) and its conjugated form, taurodeoxycholic acid (TDCA) (POR_{adj T3 vs T1}  = 1.81).

CONCLUSIONS

The bile acid levels of persons with and without NAFLD differed significantly. Among persons with NAFLD, higher levels of the conjugated forms of CA (i.e. GCA, TCA) and the secondary bile acids that derive from CA (i.e. DCA, TDCA) may indicate there is hepatic overproduction of CA, which may affect the liver via aberrant signalling mediated by the bile acids.

Unexpected Stretching of Entangled Ring Macromolecules

In the melt state at equilibrium, entangled nonconcatenated ring macromolecules adapt more compact conformations compared to their linear analogs and do not form an entanglement network. We show here that, when subjected to uniaxial stretching, they exhibit a unique response, which sets them apart from any other polymer. Remarkably, whereas both linear and ring polymers strain-harden, the viscosity of the rings increases dramatically (the melt thickens) at very low stretch rates due to the unraveling of their conformations along the stretching direction. At high rates, stretching leads to viscosity thinning similar to that of entangled linear polymers, albeit with subtle differences.

Direct Assessment of Tube Dilation in Entangled Polymers

A key ingredient within theories focusing on the rheology of entangled polymers is the way how the topological constraints of an entangled chain are lifted by unconstrained segments, i.e., how the constraining tube is dilated. This important question has been addressed by directly measuring the tube diameter d at the scale of the tube by neutron spin echo spectroscopy. The tube diameter d and plateau modulus G_{N}^{0} of highly entangled polyethylene oxide (PEO) chains of volume fraction c that are diluted by low molecular PEO show a concentration dependence d∝c^{a/2} and G_{N}^{0}∝c^{1+a} with an exponent a close to 4/3. This result allows the clear discrimination between different theoretical models that predict 4/3 or other values between 1 and 2 and provides an important ingredient to tube model theories.

A rare case of Brooke-Spiegler syndrome: integrated surgical treatment of multiple giant eccrine spiradenomas of the head and neck in a young girl

INTRODUCTION

The authors present a "four-step" integrated surgical protocol to treat a rare case of multiple giant eccrine spiradenoma (ES) of the head and neck in a young patient.

PRESENTATION OF CASE

An 18-year-old female patient presented with multiple swellings in the head and neck regions. The patient had a severe psychological trauma with a negative impact on her social life. Physical examination revealed multiple papulo-nodular swellings measuring between 5 cm × 8 cm and up to 10 cm × 20 cm in size with cerebriform aspect and soft consistency. Major lesions were located in the scalp, frontal area, neck, occipitotemporal, and retroauricular regions. Tissue biopsy found a benign composite adnexal neoplasm consisted in ES, trichoepithelioma, and cylindroma, a typical feature of Brooke-Spiegler Syndrome. A staged excision was planned, and available reconstructive options were considered. Scalp reconstruction included tissue expansions, advancement flaps, skin grafts, and dermal regeneration template (Integra^®). All treatments were successful, and no recurrence was observed. The patient returned to a normal social life, and a radical excision with satisfying aesthetic results was achieved.

DISCUSSION

Although adnexal tumors are benign in most of the cases, these lesions are prone to arise in the craniofacial region, thereby causing aesthetic discomfort associated with pain, hemorrhage, and infection to the patient every day. Furthermore, there is a potential risk of malignant transformation. These concerns demonstrate the need to establish a surgical protocol for the treatment of adnexal tumors.

CONCLUSIONS

Our integrated surgical approach showed excellent aesthetic and functional results with benefits to the patient's life and complete oncological excision.

Vitamin D-Binding Protein and Risk of Renal Cell Carcinoma in the Cancer Prevention Study-II Cohort

Background: Kidney cancer has several well-established risk factors, including smoking, obesity, and hypertension. These factors do not, however, completely account for its etiology. One previous study of vitamin D-binding protein (DBP) and risk of renal cell carcinoma found a striking inverse association that warranted replication.Methods: We conducted a nested case-control study in the American Cancer Society Cancer Prevention Study-II Nutrition Cohort to prospectively examine circulating DBP concentration and renal cell carcinoma risk. Cases (n = 87) were matched 1:1 to controls on gender, race, age (±5 years), and date of blood collection (±30 days). ORs and 95% confidence intervals (CIs) were estimated for quartiles of DBP using conditional logistic regression.Results: There was a statistically significant inverse trend across quartiles of DBP such that participants with higher DBP had a markedly decreased risk of renal cell carcinoma (vs. Q1: Q2 OR, 0.93; 95% CI, 0.41-2.11; Q3 OR, 0.42; 95% CI, 0.15-1.15; Q4 OR, 0.33; 95% CI, 0.10-1.06; P _trend = 0.03).Conclusions: Our findings demonstrate a strong inverse association between circulating DBP and risk of renal cell carcinoma, supporting the findings from previous research.Impact: This is only the second study to examine DBP and risk of kidney cancer, and one of only a handful of studies to examine circulating DBP and risk of cancer at any site. Our findings support emerging evidence for an etiologic role of DBP in cancer and may provide insights into the etiology of kidney and other cancers. Cancer Epidemiol Biomarkers Prev; 27(10); 1203-7. ©2018 AACR.

Association of 25-Hydroxyvitamin D with Liver Cancer Incidence and Chronic Liver Disease Mortality in Finnish Male Smokers of the ATBC Study

Background: Although circulating 25-hydroxyvitamin D [25(OH)D] concentrations were linked to liver cancer and chronic liver disease (CLD) in laboratory studies, few epidemiologic studies have addressed the associations.Methods: Within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, we measured 25(OH)D in baseline serum of 202 incident liver cancer cases and 225 CLD deaths that occurred during nearly 25 years of follow-up, and 427 controls. ORs and 95% confidence intervals (CIs) were estimated using unconditional logistic regression. We examined predetermined clinically defined cut-points, and season-specific and season-standardized quartiles.Results: Low serum 25(OH)D concentrations were associated with higher risk of liver cancer (<25 nmol/L vs. ≥50 nmol/L: 1.98; 95% CI, 1.22-3.20; P_trend across categories = 0.003) and CLD mortality (1.93; 95% CI, 1.23-3.03; P_trend = 0.006) in models adjusted for age and date of blood draw. After additional adjustment for body mass index, diabetes, smoking, and other potential confounders, the association remained statistically significant for liver cancer (1.91; 95% CI, 1.16-3.15; P_trend = 0.008), but was somewhat attenuated for CLD mortality (1.67; 95% CI, 1.02-2.75; P_trend = 0.05). Associations were similar for analyses using season-specific and season-standardized quartiles, and after excluding participants with diabetes, or hepatitis B or C.Conclusions: Our results suggest a possible preventive role for vitamin D against liver cancer and CLD, although the importance of the liver for vitamin D metabolism and the lack of information about underlying liver disease makes reverse causality a concern.Impact: Future studies are needed to evaluate associations of vitamin D with liver cancer and liver disease in other populations, particularly those with a different constellation of risk factors. Cancer Epidemiol Biomarkers Prev; 27(9); 1075-82. ©2018 AACR.

The role of lipofilling in reconstructions with dermal regeneration template: clinical and histological assessment

Skin and soft tissue reconstruction represents one of the most debated issues of plastic surgery. The advent of regenerative medicine has shown new pathways with the use of lipofilling and dermal regeneration templates. The aim of this study was to investigate the histological and clinical modifications occurring after lipofilling in the areas previously reconstructed with Integra® and an autologous thin dermal-epidermal graft. Histological and immunohistochemical analysis were performed on nine patients to compare skin before and after lipofilling. Pre- and post-operative examinations (POSAS, VAS scale) were carried out as well as taking clinical photographs. The authors detected an overall clinical and histological improvement in all cases. Data obtained from POSAS and VAS scale showed a statistically significant (p less than 0.05) improvement concerning all variables investigated before surgery. The biopsies revealed qualitative modifications with hematoxylin-eosin and Masson trichrome stain. Immunohistochemistry with CD31 antibody also demonstrated quantitative changes with an increased number of vessels. The photographs enabled to compare the clinical situation before and after lipofilling with better aesthetic outcomes. Lipofilling gave good functional and aesthetic results in the areas treated with Integra® and autologous thin dermal-epidermal grafts.

Adipose-derived mesenchymal stromal (stem) cells differentiate to osteoblast and chondroblast lineages upon incubation with conditioned media from dental pulp stem cell-derived osteoblasts and auricle cartilage chondrocytes

The potential of adipose-derived mesenchymal stromal (stem) cells (ADSCs) to differentiate into either osteoblasts or chondrocytes is controversial. In this study we investigated the multicapacity potential of ADSCs to differentiate towards adipocyte, osteoblast, and chondrocyte lineages when cells are seeded onto plastic in comparison with incubation with conditioned media (CM) obtained from differentiated cell types.ADSCs, obtained from liposuctions, were characterized for mesenchymal and hematopoietic markers by cytofluorimetry. Their differentiation capacity towards adipocytes, osteoblasts, and chondrocytes was investigated by histochemistry methods (Oil-Red-O staining, Safranin O and Alizarin Red staining, respectively). Dental pulp stem cells (DPSCs) and dedifferentiated auricle derived-chondrocytes were differentiated towards osteoblastic and chondrocytic lineages respectively, and the CM obtained from these cultures was used to induce differentiation of ADSCs. ADSCs were positive for mesenchymal markers (CD29, CD105, CD73, CD44), but not for hematopoietic lineage markers (CD14, CD34, CD45) and this behavior was conserved from the isolation up to the fifth passage. While ADSCs were readily differentiated in adipocytes, they were not towards chondrocytes and osteoblastic lineages, a behavior different from that of bone marrow-derived MSCs that differentiated into the three lineages at two weeks post-induction. Only ADSCs treated with CM from cultured chondrocytes and DPSCs, produced glycosaminoglycans and mineralized matrix. These results indicate that ADSCs need growth/morphogenic factor supplementation from the tissue environment to be appropriately differentiated to mesodermic lineages.

Prediagnostic Sex Steroid Hormones in Relation to Male Breast Cancer Risk

PURPOSE

Although previous studies have implicated a variety of hormone-related risk factors in the etiology of male breast cancers, no previous studies have examined the effects of endogenous hormones.

PATIENTS AND METHODS

Within the Male Breast Cancer Pooling Project, an international consortium comprising 21 case-control and cohort investigations, a subset of seven prospective cohort studies were able to contribute prediagnostic serum or plasma samples for hormone quantitation. Using a nested case-control design, multivariable unconditional logistic regression analyses estimated odds ratios and 95% CIs for associations between male breast cancer risk and 11 individual estrogens and androgens, as well as selected ratios of these analytes.

RESULTS

Data from 101 cases and 217 matched controls were analyzed. After adjustment for age and date of blood draw, race, and body mass index, androgens were found to be largely unrelated to risk, but circulating estradiol levels showed a significant association. Men in the highest quartile had an odds ratio of 2.47 (95% CI, 1.10 to 5.58) compared with those in the lowest quartile (trend P = .06). Assessment of estradiol as a ratio to various individual androgens or sum of androgens showed no further enhancement of risk. These relations were not significantly modified by either age or body mass index, although estradiol was slightly more strongly related to breast cancers occurring among younger (age < 67 years) than older men.

CONCLUSION

Our results support the notion of an important role for estradiol in the etiology of male breast cancers, similar to female breast cancers.

Penile length is a very important factor for cosmesis, function and psychosexual development in patients affected by hypospadias: Results from a long-term longitudinal cohort study

Few studies of long-term outcome of hypospadias treatment in terms of voiding, surgical complications, sexual functioning, intimate relationships and cosmetic results have been investigated and contrasting results have been obtained so far. The aim of our study is to investigate the long-term outcome of urinary and sexual function, cosmesis and the quality of intimate relationships in a series of hypospadias. In this study, 42 patients who underwent surgery for hypospadias were prospectively followed for 15 years. Medical records provided the hypospadias data, the number of reconstructive operations and the reconstruction technique that was used. Patients underwent physical examination, including penile length measurement and completed International Prostatic Symptoms Score (I-PSS), International Index Of Erectile Function (IIEF 15) and the Penile Perception Score questionnaire (PPPS). Twenty patients agreed to participate in the study. At the enrolment, the median value of HOSE was 13, as regards PPPS, 18/20 (90%) were satisfied, while in 1998 only 80% were satisfied. No significant statistical difference has been reported from the results obtained at enrolment and those obtained at follow-up, in terms of PPPS (P = 0.81), IPSS and IIEF-15. Penile length was 6.5 cm flaccid and 10.5 cm stretched. Our data show how cosmesis, function and psychosexual development for these patients are highly connected to surgical outcome, which is understood to be a decrease in penile size.

Tobacco and alcohol in relation to male breast cancer: an analysis of the male breast cancer pooling project consortium

BACKGROUND

The etiology of male breast cancer is poorly understood, partly due to its relative rarity. Although tobacco and alcohol exposures are known carcinogens, their association with male breast cancer risk remains ill-defined.

METHODS

The Male Breast Cancer Pooling Project consortium provided 2,378 cases and 51,959 controls for analysis from 10 case-control and 10 cohort studies. Individual participant data were harmonized and pooled. Unconditional logistic regression was used to estimate study design-specific (case-control/cohort) ORs and 95% confidence intervals (CI), which were then combined using fixed-effects meta-analysis.

RESULTS

Cigarette smoking status, smoking pack-years, duration, intensity, and age at initiation were not associated with male breast cancer risk. Relations with cigar and pipe smoking, tobacco chewing, and snuff use were also null. Recent alcohol consumption and average grams of alcohol consumed per day were also not associated with risk; only one subanalysis of very high recent alcohol consumption (>60 g/day) was tentatively associated with male breast cancer (ORunexposed referent = 1.29; 95% CI, 0.97-1.71; OR>0-<7 g/day referent = 1.36; 95% CI, 1.04-1.77). Specific alcoholic beverage types were not associated with male breast cancer. Relations were not altered when stratified by age or body mass index.

CONCLUSIONS

In this analysis of the Male Breast Cancer Pooling Project, we found little evidence that tobacco and alcohol exposures were associated with risk of male breast cancer.

IMPACT

Tobacco and alcohol do not appear to be carcinogenic for male breast cancer. Future studies should aim to assess these exposures in relation to subtypes of male breast cancer.

Association of seropositivity to Helicobacter species and biliary tract cancer in the ATBC study

Helicobacter have been detected in human bile and hepatobiliary tissue. Despite evidence that Helicobacter species promote gallstone formation and hepatobiliary tumors in laboratory studies, it remains unclear whether Helicobacter species contribute to these cancers in humans. We used a multiplex panel to assess whether seropositivity to 15 Helicobacter pylori proteins was associated with subsequent incidence of hepatobiliary cancers in the Finnish Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study. We included 64 biliary cancers, 122 liver cancers, and 224 age-matched controls which occurred over the course of 22 years. Helicobacter pylori seropositivity was defined as those positive to ≥ 4 antigens. Odds ratios (OR) and 95% confidence intervals were adjusted for major hepatobiliary cancer risk factors. Among the controls, 88% were seropositive to H. pylori at baseline. Among those who subsequently developed hepatobiliary cancer, the prevalence of seropositivity was higher: 100% for gallbladder cancer, 97% of extrahepatic bile duct cancer, 91% of ampula of Vater cancer, 96% of intrahepatic bile duct cancer, and 94% of hepatocellular carcinoma. Although the OR for gallbladder cancer could not be calculated, the OR for the other sites were 7.01 (95% confidence interval [CI]: 0.79-62.33), 2.21 (0.19-25.52), 10.67 (0.76-150.08), and 1.20 (0.42-3.45), respectively, with an OR of 5.47 (95% CI: 1.17-25.65) observed for the biliary tract cancers combined. ORs above 1 were observed for many of the investigated antigens, although most of these associations were not statistically significant.

CONCLUSION

Seropositivity to H. pylori proteins was associated with an increased risk of biliary tract cancers in ATBC. Further studies are needed to confirm our findings and to determine how H. pylori might influence the risk of biliary tract cancer.

Long-term follow-up in infantile-onset lambert-eaton myasthenic syndrome

Lambert-Eaton myasthenic syndrome is a neuromuscular junction disorder characterized by proximal limb muscle weakness, fatigability, decreased deep-tendon reflexes, and autonomic symptoms. There are 2 forms of Lambert-Eaton myasthenic syndrome: one most frequently associated with small-cell lung cancer (P-Lambert-Eaton myasthenic syndrome) and the other that is a pure autoimmune form (NP-Lambert-Eaton myasthenic syndrome). Lambert-Eaton myasthenic syndrome is a very rare disorder in children younger than age 12 years. Herein, we report a 25-year-old man with NP-Lambert-Eaton myasthenic syndrome, which onset was at the age of 10 years. To date, this is the most long-term follow-up of NP-Lambert-Eaton myasthenic syndrome in childhood. In our patient, the only symptomatic treatment with 3,4-diaminopyridine phosphate has been sufficient to guarantee him a good quality of life. Our data remind physicians to keep in mind the diagnosis of Lambert-Eaton myasthenic syndrome in children with a proximal myopathic pattern and they confirm the specificity of compound muscle action potential incremental pattern after brief maximal effort in Lambert-Eaton myasthenic syndrome.

Continuous-wave Pr³⁺:BaY₂F₈ and Pr³⁺:LiYF₄ lasers in the cyan-blue spectral region

We report on the first, to the best of our knowledge, continuous-wave quasi three-level lasers emitting in the cyan-blue spectral range in praseodymium-doped crystalline materials. Applying Pr(3+):BaY2F8 as an active medium, up to 201 mW of output power at 495 nm could be obtained with a slope efficiency of 27% under pumping with an optically pumped semiconductor laser (2ω-OPSL) at 480 nm. In the same pumping scheme using Pr(3+):LiYF4, output powers up to 70 mW were realized at 491 and 500 nm, respectively. With Pr(3+):BaY2F8, diode-pumped laser operation with up to 11% slope efficiency and 44 mW output power was also achieved. In the latter case, detailed investigations on the temperature dependency of the laser output were conducted. Moreover, comparative experiments were carried out for the first time, to the best of our knowledge, with green-emitting Pr(3+):BaY2F8 lasers at 524 and 553 nm both under diode and 2ω-OPSL excitation.

Pre-Clinical Evaluation of a New Coral-Based Bone Scaffold

Coral is used worldwide for bone reconstruction. The favorable characteristics that make this material desirable for implantation are (i) osteoinduction, (ii) and osteoconduction. These proprieties have been demonstrated by in vivo studies with animal models and clinical trials over a twenty-year period. Also poly(2-hydroxyethylmethacrylate) [poly(HEMA)] is a widely used biomaterial. By using coral and poly(HEMA), a scaffold for bone reconstruction application has been recently synthesized. Cytological, histological and genetic analyses were performed to characterize this new alloplastic material. Four samples were analyzed: (a) white coral (WC), (b) red coral (RC), (c) WC plus polymer (WCP) and (d) RC plus polymer (RCP). Quantification of mitochondrial dehydrogenase activity by MTT assay was performed as indirect detector of cytotoxicity. In vivo effects were revealed by implanting corals and coral-based polymers in rabbit tibia. Samples were collected after 4 weeks and subjected to histological analysis. To evaluate the genetic response of cells to corals and coral-derived polymers an osteoblast-like cell line (i.e. MG63) was cultured in wells containing (a) medium, (b) medium plus corals and (c) medium plus two types of scaffolds (RCP or WCP). RNAs extracted from cells were retro-transcribed and hybridized on DNA 19.2K microarrays. No cytotoxicity was detected in corals and coral-based biopolymers. No inflammation or adverse effect was revealed by histological examination. By microarray analysis 154 clones were differentially expressed between RC and WC (81 up and 73 down regulated) whereas only 15 clones were repressed by the polymer. Histological evaluation not only confirmed that coral is a biocompatible material, but also that the polymer has no adverse effect. Microarray results were in agreement with cytological and histological analyses and provided further data regarding the genetic effects of RC, WC and the new polymer.

Anthropometric and hormonal risk factors for male breast cancer: male breast cancer pooling project results

BACKGROUND

The etiology of male breast cancer is poorly understood, partly because of its relative rarity. Although genetic factors are involved, less is known regarding the role of anthropometric and hormonally related risk factors.

METHODS

In the Male Breast Cancer Pooling Project, a consortium of 11 case-control and 10 cohort investigations involving 2405 case patients (n = 1190 from case-control and n = 1215 from cohort studies) and 52013 control subjects, individual participant data were harmonized and pooled. Unconditional logistic regression generated study design-specific (case-control/cohort) odds ratios (ORs) and 95% confidence intervals (CIs), with exposure estimates combined using fixed effects meta-analysis. All statistical tests were two-sided.

RESULTS

Risk was statistically significantly associated with weight (highest/lowest tertile: OR = 1.36; 95% CI = 1.18 to 1.57), height (OR = 1.18; 95% CI = 1.01 to 1.38), and body mass index (BMI; OR = 1.30; 95% CI = 1.12 to 1.51), with evidence that recent rather than distant BMI was the strongest predictor. Klinefelter syndrome (OR = 24.7; 95% CI = 8.94 to 68.4) and gynecomastia (OR = 9.78; 95% CI = 7.52 to 12.7) were also statistically significantly associated with risk, relations that were independent of BMI. Diabetes also emerged as an independent risk factor (OR = 1.19; 95% CI = 1.04 to 1.37). There were also suggestive relations with cryptorchidism (OR = 2.18; 95% CI = 0.96 to 4.94) and orchitis (OR = 1.43; 95% CI = 1.02 to 1.99). Although age at onset of puberty and histories of infertility were unrelated to risk, never having had children was statistically significantly related (OR = 1.29; 95% CI = 1.01 to 1.66). Among individuals diagnosed at older ages, a history of fractures was statistically significantly related (OR = 1.41; 95% CI = 1.07 to 1.86).

CONCLUSIONS

Consistent findings across case-control and cohort investigations, complemented by pooled analyses, indicated important roles for anthropometric and hormonal risk factors in the etiology of male breast cancer. Further investigation should focus on potential roles of endogenous hormones.

Abstract A59: Serum 25-hydroxyvitamin D and risk of incident liver cancer and chronic liver disease mortality in Finnish men

Introduction: Vitamin D has generated great interest as a potential preventative agent of chronic disease. For example, laboratory studies suggest that vitamin D has anti-proliferative, anti-inflammation, pro-differentiation, and pro-apoptotic properties. Epidemiologic studies have linked high vitamin D levels with some cancers, yet few studies have examined possible associations with liver cancer or chronic liver disease. Therefore, we evaluated the association of serum 25-hydroxyvitamin D (25(OH)D) with incident liver cancer and chronic liver disease mortality in a case-control study nested within the prospective Alpha-Tocopherol and Beta-Carotene Cancer Prevention (ATBC) Study, a cohort of Finnish male smokers.

Methods: The ATBC Study was a randomized primary prevention trial of α-tocopherol and β-carotene supplementation where 29,133 Finnish male smokers, aged 50-69, were recruited from 1985 to 1988 and randomized to daily supplementation of α-tocopherol (50 mg), β-carotene (20 mg), both, or placebo. Supplementation ended in April 1993 (median 6.1 years); however, participants have been followed since that time. At baseline, participants underwent a physical examination by registered nurses to measure height and weight, and to collect an overnight fasting blood sample. Participants also completed a baseline questionnaire concerning their tobacco smoking, general risk factors, diet and their medical history. Serum 25(OH)D levels was measured for 202 incident liver cancer cases (ICD-9=155 and ICD-10=C22), 225 chronic liver disease deaths (CD-9=571 and ICD-10=K70, K73, or K74) occurring between baseline and December 31, 2009, and 427 liver cancer-free controls matched with cases by age and date of blood draw. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression models, adjusting for age, date of blood draw, BMI, history of diabetes, number of cigarettes smoked per day, daily intakes of alcohol and coffee, serum α-tocopherol, β-carotene, and cholesterol.

Results: High serum 25(OH)D levels were inversely associated with both incident liver cancer and chronic liver disease in models adjusted for age and date of blood draw. After multivariate adjustment, associations remained similar for incident liver cancer (season-specific quartile 4 (Q4) vs. quartile 1 (Q1) OR=0.53, 95% CI=0.31-0.89, P-trend=0.007) but were attenuated somewhat for chronic liver disease mortality (Q4 vs. Q1 OR=0.71, 95% CI=0.41-1.25, P-trend=0.23). Associations were similar in analyses using clinical vitamin D cutpoints and season-standardized quartiles, and in analyses stratified by season of blood collection and intervention group. Similar associations were also observed among cases occurring more than fifteen years after baseline and in analyses performed after excluding cases seropositive for hepatitis B and C viruses.

Conclusions: Men with higher serum 25(OH)D levels had a lower risk of incident liver cancer. A similar pattern was observed for chronic liver disease mortality, although associations for this outcome were not statistically significant. Our observations suggest that high vitamin D status may protect against the development or progression of these diseases.

Citation Format: Gabriel Y. Lai, Jian-Bing Wang, Stephanie J. Weinstein, Dominick Parisi, Ronald L. Horst, Philip R. Taylor, Katherine A. McGlynn, Satu Månnistö, Demetrius Albanes, Neal D. Freedman. Serum 25-hydroxyvitamin D and risk of incident liver cancer and chronic liver disease mortality in Finnish men. [abstract]. In: Proceedings of the Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2013 Oct 27-30; National Harbor, MD. Philadelphia (PA): AACR; Can Prev Res 2013;6(11 Suppl): Abstract nr A59.

Serum 25-hydroxy vitamin D and prostate cancer risk in a large nested case-control study

BACKGROUND

Vitamin D compounds inhibit prostate tumorigenesis experimentally, but epidemiologic data are inconsistent with respect to prostate cancer risk, with some studies suggesting nonsignificant positive associations.

METHODS

The 25-hydroxy vitamin D [25(OH)D]-prostate cancer relation was examined in a nested case-control study within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study of 50- to 69-year-old Finnish men. We matched 1,000 controls to 1,000 cases diagnosed during up to 20 years of follow-up on the basis of age (±1 year) and fasting blood collection date (±30 days). Conditional multivariate logistic regression models estimated ORs and 95% CIs. All statistical significance testing was 2-sided.

RESULTS

Cases had nonsignificantly 3% higher serum 25(OH)D levels (P = 0.19). ORs (95% CIs) for increasing season-specific quintiles of 25(OH)D concentrations were 1.00 (reference), 1.29 (0.95-1.74), 1.34 (1.00-1.80), 1.26 (0.93-1.72), and 1.56 (1.15-2.12), with P(trend) = 0.01. Analyses based on prespecified clinical categories and season-adjusted values yielded similar results. These findings seemed stronger for aggressive disease [OR (95% CI) for fifth quintile of serum 25(OH)D [1.70 (1.05-2.76), P(trend) = 0.02], among men with greater physical activity [1.85 (1.26-2.72), P(trend) = 0.002], higher concentrations of serum total cholesterol [2.09 (1.36-3.21), P(trend) = 0.003] or α-tocopherol [2.00 (1.30-3.07), P(trend) = 0.01] and higher intakes of total calcium [1.82 (1.20-2.76), P(trend) = 0.01] or vitamin D [1.69 (1.04-2.75), P(trend) = 0.08], or among those who had received the trial α-tocopherol supplements [1.74 (1.15-2.64), P(trend) = 0.006].

CONCLUSION

Our findings indicate that men with higher vitamin D blood levels are at increased risk of developing prostate cancer.

IMPACT

Greater caution is warranted with respect to recommendations for high-dose vitamin D supplementation and higher population target blood levels.

Serum 25-hydroxyvitamin D and risk of lung cancer in male smokers: a nested case-control study

Background

A role for vitamin D in cancer risk reduction has been hypothesized, but few data exist for lung cancer. We investigated the relationship between vitamin D status, using circulating 25-hydroxyvitamin D [25(OH)D], and lung cancer risk in a nested case-control study within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study of Finnish male smokers.

Methods

Lung cancer cases (n = 500) were randomly selected based on month of blood collection, and 500 controls were matched to them based on age and blood collection date. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multivariate-adjusted conditional logistic regression. To account for seasonal variation in 25(OH)D concentrations, season-specific and season-standardized quintiles of 25(OH)D were examined, and models were also stratified on season of blood collection (darker season = November–April and sunnier season = May–October). Pre-determined, clinically-defined cutpoints for 25(OH)D and 25(OH)D as a continuous measure were also examined.

Results

Overall, 25(OH)D was not associated with lung cancer. Risks were 1.08 (95% CI 0.67–1.75) and 0.83 (95% CI 0.53–1.31) in the highest vs. lowest season-specific and season-standardized quintiles of 25(OH)D, respectively, and 0.91 (95% CI 0.48–1.72) for the ≥75 vs. <25 nmol/L clinical categories. Inverse associations were, however, suggested for subjects with blood collections from November–April, with ORs of 0.77 (95% CI 0.41–1.45, p-trend = 0.05) and 0.65 (95% CI 0.37–1.14, p-trend = 0.07) in the highest vs. lowest season-specific and season-standardized quintiles of 25(OH)D, respectively, and 0.61 (95% CI 0.24–1.52, p-trend = 0.01) for ≥75 vs. <25 nmol/L. We also found 11% lower risk for a 10 nmol/L increase in 25(OH)D in the darker season based on the continuous measure (OR = 0.89, 95% CI 0.81–0.98, p = 0.02).

Conclusion

In this prospective study of male smokers, circulating 25(OH)D was not associated with lung cancer risk overall, although inverse associations were suggested among those whose blood was drawn during darker months.

Circulating 25-hydroxyvitamin D and the risk of rarer cancers: Design and methods of the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers

The Cohort Consortium Vitamin D Pooling Project of Rarer Cancers (VDPP), a consortium of 10 prospective cohort studies from the United States, Finland, and China, was formed to examine the associations between circulating 25-hydroxyvitamin D (25(OH)D) concentrations and the risk of rarer cancers. Cases (total n = 5,491) included incident primary endometrial (n = 830), kidney (n = 775), ovarian (n = 516), pancreatic (n = 952), and upper gastrointestinal tract (n = 1,065) cancers and non-Hodgkin lymphoma (n = 1,353) diagnosed in the participating cohorts. At least 1 control was matched to each case on age, date of blood collection (1974-2006), sex, and race/ethnicity (n = 6,714). Covariate data were obtained from each cohort in a standardized manner. The majority of the serum or plasma samples were assayed in a central laboratory using a direct, competitive chemiluminescence immunoassay on the DiaSorin LIAISON platform (DiaSorin, Inc., Stillwater, Minnesota). Masked quality control samples included serum standards from the US National Institute of Standards and Technology. Conditional logistic regression analyses were conducted using clinically defined cutpoints, with 50-<75 nmol/L as the reference category. Meta-analyses were also conducted using inverse-variance weights in random-effects models. This consortium approach permits estimation of the association between 25(OH)D and several rarer cancers with high accuracy and precision across a wide range of 25(OH)D concentrations.

Epidemiology of pulmonary embolism in Apulia from analysis of current data

BACKGROUND AND AIMS

Pulmonary embolism (PE) is a relatively common cardiovascular emergency: present evidence suggests that PE is the third most acute cardiovascular disease after cardiac ischemic syndromes and stroke. The aim of this study is to evaluate hospital admissions for PE in the Apulia Region of Italy in the period 2001-2007 through an analysis of the Apulia Region hospital patient discharge database.

METHODS

Patients were selected on the basis of admissions between 01/01/2001 and 31/12/2007 with ICD-9-CM code of 415.11 (Iatrogenic pulmonary embolism and infarction) or 415.19 (Other pulmonary embolism and infarction) as principal or secondary diagnosis.

RESULTS

The number of patients selected from the database was 4,303. The raw annual admission data shows an increasing trend from 13.9x100,000 residents in 2001 to 18.9 x 100,000 residents in 2007. The average patient age was 68.7 years and 59% were females and 41%. There were 470 deaths in hospital (10.9% of patients).

CONCLUSIONS

PE is associated with much health care and a substantial economic burden, yet many PE and general venous thromboembolism (VTE) events are preventable. It remains the responsibility of individual hospitals to identify specific areas in which they can improve their VTE prophylaxis rates to obtain positive results from the reporting initiatives and incentive programs.

Efficient in-band pumped Ho:LuLiF(4) 2 microm laser

An efficient Ho:LuLiF(4) laser in-band pumped by a cladding-pumped Tm-doped silica fiber laser operating at 1937 nm is reported. At low-cavity output coupling, the Ho:LuLiF(4) laser yielded 5.1 W of output at a wavelength of 2066 nm for 8.0 W of absorbed pump power with a slope efficiency of 70%. At high-cavity output coupling, the lasing wavelength shifted to 2053 nm and the laser produced an output power of 5.4 W with a slope efficiency of 76%. The beam propagation factor (M(2)) was measured to be approximately 1.1 at the maximum output power confirming fundamental transverse mode (TEM(oo)) operation. The influence of resonator design on laser performance is discussed, along with prospects for further power scaling and improvement of the laser efficiency.

Diode-pumped single-frequency Tm:LiLuF(4) ring laser

We report a room-temperature single-frequency Tm:LiLuF(4) laser with a maximum output power of 120 mW, a slope efficiency of 13%, and a wavelength tunability range from 1875 to 1895 nm. Both frequency and relative intensity noise have been investigated, showing an emission linewidth of approximately 300 kHz over 1 ms observation time and an intensity noise spectrum limited by quantum noise for Fourier frequencies larger than 5 MHz.

Morphostructural changes in transferred fasciocutaneous free flaps: a preliminary clinical and immunohistochemical report

Many local factors, yet to be investigated, can promote changes in tissue transferred by microsurgical technique into the recipient site. Several studies have attempted to assess the nature of modifications that occur in the vascular network of such a flap after transfer. Although these investigations have interesting conclusions, the majority of them were based only on indirect evaluations. The aim of this study was to detect, by histological and statistical analysis, the morphostructural changes that occurred in fasciocutaneous free flaps transferred to the cephalic region or to the lower limb. Patients were enrolled in this study only when neither local inflammatory reactions nor systemic diseases were observed at the time of biopsy. Six patients consented to undergo biopsy at both the donor and the recipient area of a previously transferred fasciocutaneous free flap. Three flaps were used for facial reconstruction, and three others for lower limb reconstruction. Standard staining and immunohistochemical investigations were performed. The sections were also analysed by specific software. Statistical analysis of the data was performed using the student's t-test and Fisher's test. In five out of six transferred flaps (83%), there was increased microvascularity compared to the donor area. It was correlated to the neoangiogenesis in the dermal layer of the flaps. In five recipient sites there were more new vessels. In particular, a higher score of angiogenesis was observed both in the cheek (one flap) and in the non weight-bearing area of the foot (two flaps) (P<0.001). Some differences in microvascularity between the donor and the recipient site in the same flap were related to the specific recipient site. This represents the first demonstration of adaptation of fasciocutaneous free flaps to the recipient area, as well as to their new function, at both the macroscopic and microscopic level.

Microsurgical treatment of injury to peripheral nerves in upper and lower limbs: a critical review of the last 8 years

Nerve injuries to the upper and inferior limbs represent a common event due both to home and working accidents. Minor traumas can lead to severe disabilities if a wrong treatment is carried out. From 1997 to 2005, 920 patients were observed with a total of 1,200 major or minor nerves injuries operated. In 852 cases acute lesions treated. In 68 patients we reviewed old injuries. In 707 patients direct nerve suture and in 145 patients nerve grafts were carried out. One to 8 years follow up observed. Different protocols were adopted according to the injury: simple cut, complex lesion or surgical revision. Results were evaluated during the follow up period with different models: motor evaluation in six levels (BMRC), sensitive evaluation in five levels (HIGHET), and global evaluation with four grades (from the worst to the best result). Nerve healing is a complex biological phenomenon influenced by many parameters related both to the patient characteristics and nerve lesion. Functional and esthetical outcomes vary also according to: age, cultural and economic condition, health status, and smoking. Post operative rehabilitation is mandatory to obtain an acceptable functional result. Nerve injuries to the upper and inferior limbs represent a challenge for the microsurgeon. Ultimate success in nerve surgery is judged by functional as well as cosmetic parameters. Only patients with the appropriate indication should be operated and always by a skilled surgeon.

Continuous-wave ultraviolet generation at 320 nm by intracavity frequency doubling of red-emitting Praseodymium lasers

We describe a new approach for the generation of coherent ultraviolet radiation. Continuous-wave ultraviolet light at 320 nm has been obtained by intracavity frequency doubling of red-emitting Praseodymium lasers. Lasing at the 640-nm fundamental wavelength in Pr:LiYF(4) and Pr:BaY(2)F(8) was realized by employing an optically pumped semiconductor laser at 480 nm as pump source.Using LiB(3)O(5) as nonlinear medium, ~19 mW of ultraviolet radiation with ~9% optical efficiency with respect to absorbed power was reached for both laser crystals; the visible-to-ultraviolet conversion efficiency was 26% and 35% for Pr:LiYF(4) and Pr:BaY(2)F(8), respectively.

Experimental evaluation of the cw lasing threshold for a Ce:LiCaAlF6 laser

We present an experimental technique that allows the direct measurement of the continuous wave (cw) lasing threshold and the slope efficiency of a Ce:LiCaAlF6 (Ce:LiCAF) laser source by means of time-resolved measurement in the pulsed regime. We used a long-pulse-duration source to pump a tunable laser and a high-efficiency nondispersive laser in a quasi-stationary lasing regime. We compare the experimental results with earlier theoretical evaluations, and we demonstrate the feasibility of a cw Ce:LiCAF laser. Under the conditions discussed here, our technique can be applied to all the active media that achieved pulsed laser emission to investigate their potential as cw laser active media.

Efficient, diode-pumped Tm(3)+:BaY(2)F(8) vibronic laser

In this work we report the spectroscopy and laser results of several Thulium doped BaY(2)F(8) single crystals grown using the Czochralski technique. The doping concentration is between 2at.% and 18at.%. We performed room temperature laser experiments pumping the samples with a laser diode at 789 nm obtaining 61% as maximum optical-to-optical efficiency with a maximum output power of 290 mW and a minimum lasing threshold of 26 mW. The lasing wavelength changed with the dopant concentration from 1927 nm up to 2030 nm and the nature of the transition changed from purely electronic to vibronic, accordingly.

Dorsal open repair of proximal pole scaphoid fractures

Proximal pole fractures of the scaphoid are well suited for comprehension screw fixation. A dorsal approach allows for direct visualization of the fracture site, accurate reduction, and internal fixation. Bone grafting can also be achieved through the same incision without additional significant dissection. Successful uncomplicated union in the majority of cases with a considerably shortened period of immobilization has lead to a growing interest in this surgical procedure.

Duplication of modules facilitates the evolution of functional specialization

The evolution of simulated robots with three different architectures is studied in this article. We compare a nonmodular feed-forward network, a hardwired modular, and a duplication-based modular motor control network. We conclude that both modular architectures outperform the non-modular architecture, both in terms of rate of adaptation as well as the level of adaptation achieved. The main difference between the hardwired and duplication-based modular architectures is that in the latter the modules reached a much higher degree of functional specialization of their motor control units with regard to high-level behavioral functions. The hardwired architectures reach the same level of performance, but have a more distributed assignment of functional tasks to the motor control units. We conclude that the mechanism through which functional specialization is achieved is similar to the mechanism proposed for the evolution of duplicated genes. It is found that the duplication of multifunctional modules first leads to a change in the regulation of the module, leading to a differentiation of the functional context in which the module is used. Then the module adapts to the new functional context. After this second step the system is locked into a functionally specialized state. We suggest that functional specialization may be an evolutionary absorption state.