Historic indications for fixation of posterior malleolus fractures- where did they come from and where are we now?

INTRODUCTION

The indications for reduction and fixation of the posterior malleolus component of rotational ankle fractures have been controversial for nearly a century. This study aims to identify the historical basis for surgical intervention and trace trends in management strategies over time.

METHODS

In March 2023, a systematic review of full-text, English-language articles providing indications for surgical fixation of the posterior malleolus component of rotational ankle fractures was performed. Articles underwent title and abstract screening before undergoing full-text review.

RESULTS

Historical indications for surgical fixation were size-dependent, with fractures comprising 25 % to 33 % of the plafond recommended for internal fixation. Modern studies suggest that nonoperative management of posterior malleolus fractures below this threshold results in residual malreduction of the articular surface, syndesmotic instability, and an increased need for independent fixation of the syndesmosis.

CONCLUSIONS

Size-based indications for posterior malleolus fracture fixation are based on Level V evidence from small retrospective case series published nearly one century ago and should be retired. While the size of the posterior malleolus component cannot be ignored, additional factors like fracture morphology and location within the plafond should guide modern surgical indications. Contemporary studies indicate that reduction and fixation of small posterior malleolus fractures (comprising less than 25 % of the articular surface) are associated with improved articular reductions, tibiotalar contact pressures, syndesmotic stability with decreased need for independent fixation of the syndesmosis, and superior postoperative outcomes.

Outcomes of Patients with Preoperative Thrombocytosis After Hip Fracture Surgery

INTRODUCTION

Low platelet counts have clinically relevant effects on patient outcomes after hip fracture surgery; however, the relationship between abnormally high platelet counts and postoperative outcomes in this population is unknown.

METHODS

The ACS-NSQIP database was queried for patients who underwent hip fracture surgery between 2015 and 2019. Outcomes were compared between patients with normal platelet counts (150,000 to 450,000/μL) and thrombocytosis (>450,000/μL).

RESULTS

Eighty-six thousand three hundred eleven hip fracture patients were identified, of which 1067 (1.2%) had preoperative thrombocytosis. Compared with patients with normal platelet counts, patients with preoperative thrombocytosis had increased rates of 30-day mortality (6.4% vs 4.5%, P = 0.004; OR 1.15 [95% CI 0.88 to 1.50], P = 0.322) as well as increased rates and odds of readmission (11.4% vs 7.8%, P < 0.001; OR 1.35 [95% CI 1.10 to 1.65], P = 0.004) and venous thromboembolic events (3.2% vs 1.7%, P < 0.001; OR 1.88 [95% CI 1.31 to 2.71], P < 0.001).

CONCLUSIONS

Hip fracture patients with preoperative thrombocytosis had increased rates of early mortality as well as increased odds of venous thromboembolic events and readmission. A patient with thrombocytosis may benefit from close postoperative surveillance and careful follow-up. Future prospective studies are needed to verify causation and investigate how to mitigate adverse outcomes in hip fracture patients with preoperative thrombocytosis.

Using machine-learning to decode postoperative hip mortality Trends: Actionable insights from an extensive clinical dataset

BACKGROUND

Hip fractures are one of the most common injuries experienced by the general population. Despite advances in surgical techniques, postoperative mortality rates remain high. identifying relevant clinical factors associated with mortality is essential to preoperative risk stratification and tailored post-surgical interventions to improve patient outcomes. The purpose of this study aimed to identify preoperative risk factors and develop predictive models for increased hip fracture-related mortality within 30 days post-surgery, using one of the largest patient cohorts to date.

METHODS

Data from the American College of Surgeons National Surgical Quality Improvement Program database, comprising 107,660 hip fracture patients treated with surgical fixation was used. A penalized regression approach, least absolute shrinkage and selection operator was employed to develop two predictive models: one using preoperative factors and the second incorporating both preoperative and postoperative factors.

RESULTS

The analysis identified 68 preoperative factor outcomes associated with 30-day mortality. The combined model revealed 84 relevant factors, showing strong predictive power for determining postoperative mortality, with an AUC of 0.83.

CONCLUSIONS

The study's comprehensive methodology provides risk assessment tools for clinicians to identify high-risk patients and optimize patient-specific care.

Postoperative sepsis and septic shock after hip fracture surgery

INTRODUCTION

There is a paucity of research in the rates for sepsis and septic shock in the hip fracture population specifically, despite marked clinical and prognostic differences between these conditions. The purpose of this study was to determine the incidence, risk factors, and mortality rates for sepsis and septic shock as well as evaluate potential infectious causes in the surgical hip fracture population.

METHODS

The ACS-NSQIP (2015-2019) was queried for patients who underwent hip fracture surgery. A backward elimination multivariate regression model was used to identify risk factors for sepsis and septic shock. Multivariate regression that controlled for preoperative variables and comorbidities was used to calculate the odds of 30-day mortality.

RESULTS

Of 86,438 patients included, 871 (1.0%) developed sepsis and 490 (0.6%) developed septic shock. Risk factors for both postoperative sepsis and septic shock were male gender, DM, COPD, dependent functional status, ASA class ≥3, anemia, and hypoalbuminemia. Unique risk factors for septic shock were CHF and ventilator dependence. The 30-day mortality rate was 4.8% in aseptic patients, 16.2% in patients with sepsis, and 40.8% in patients who developed septic shock (p < 0.001). Patients with sepsis (OR 2.87 [95% CI 2.37-3.48], p < 0.001) and septic shock (OR 11.27 [95% CI 9.26-13.72], p < 0.001) had increased odds of 30-day mortality compared to patients without postoperative septicemia. Infections that preceded a diagnosis of sepsis or septic shock included urinary tract infections (24.7%, 16.5%), pneumonia (17.6%, 30.8%), and surgical site infections (8.5%, 4.1%).

CONCLUSIONS

The incidence of sepsis and septic shock after hip fracture surgery was 1.0% and 0.6%, respectively. The 30-day mortality rate was 16.2% in patients with sepsis and 40.8% in patients with septic shock. Potentially modifiable risk factors for both sepsis and septic shock were anemia and hypoalbuminemia. Urinary tract infections, pneumonia, and surgical site infections preceded the majority of cases of sepsis and septic shock. Prevention, early identification, and successful treatment of sepsis and septic shock are paramount to lowering mortality after hip fracture surgery.

Clostridium difficile colitis portends poor outcomes in lower extremity orthopaedic trauma surgery

INTRODUCTION

Clostridium difficile is the most common cause of healthcare-associated infectious diarrhea and colitis, and carries the potential for high morbidity, particularly in frail patient populations. The purpose of this study was to utilize a large nationally representative database in order to report 1.) the incidence of CDC in patients with operative lower extremity fractures, 2.) risk factors for the development of CDC, 3.) the association of CDC with length of stay (LOS), readmission, and 30-day mortality rates.

METHODS

The ACS-NSQIP (2015-2019) was queried for patients who underwent surgical fixation of lower extremity fractures. A backward elimination multivariate regression model was used to identify risk factors for CDC. Chi squared and multivariate regression that controlled for preoperative variables and comorbidities were used to compare outcomes in patients with and without CDC.

RESULTS

95,532 patients were included, 681 (0.71%) of whom developed CDC. Risk factors for CDC were advanced age, ASA class ≥ 3, smoking, dialysis, anemia, hypoalbuminemia, preoperative SIRS, preoperative wound infections, preoperative sepsis, and the use of spinal anesthesia or MAC/IV sedation. Patients with CDC had significantly increased 30-day mortality rates (10.6% vs 4.4%; OR 1.80, 95% CI 1.41-2.31), readmission (34.2% vs 7.5%; OR 5.13, 95% CI 4.36-6.05, and length of stay (7.5 days vs 5.3 days) compared to patients without CDC.

CONCLUSION

The incidence of CDC in lower extremity orthopedic trauma patients was 0.71%. An occurrence of CDC was associated with approximately a 2.5 times increase in 30-day mortality, five times the readmission rate, and a longer hospital stay compared to patients without CDC. Mitigating the spread of c. diff through improved antibiotic stewardship and prompt treatment of CDC is paramount to decreasing the burden this infection imposes on orthopedic trauma patients and the healthcare system.

Healthy lifestyle index and risk of gastric adenocarcinoma in the EPIC cohort study

Several modifiable lifestyle factors, including smoking, alcohol, certain dietary factors and weight are independently associated with gastric cancer (GC); however, their combined impact on GC risk is unknown. We constructed a healthy lifestyle index to investigate the joint influence of these behaviors on GC risk within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. The analysis included 461,550 participants (662 first incident GC cases) with a mean follow-up of 11.4 years. A healthy lifestyle index was constructed, assigning 1 point for each healthy behavior related to smoking status, alcohol consumption and diet quality (represented by the Mediterranean diet) for assessing overall GC and also body mass index for cardia GC and 0 points otherwise. Risk of GC was calculated using Cox proportional hazards regression models while adjusting for relevant confounders. The highest versus lowest score in the healthy lifestyle index was associated with a significant lower risk of GC, by 51% overall (HR 0.49 95% CI 0.35, 0.70), by 77% for cardia GC (HR 0.23 95% CI 0.08, 0.68) and by 47% for noncardia GC (HR 0.53 (95% CI 0.32, 0.87), p-trends<0.001. Population attributable risk calculations showed that 18.8% of all GC and 62.4% of cardia GC cases could have been prevented if participants in this population had followed the healthy lifestyle behaviors of this index. Adopting several healthy lifestyle behaviors including not smoking, limiting alcohol consumption, eating a healthy diet and maintaining a normal weight is associated with a large decreased risk of GC.

Adherence to the Mediterranean diet and risk of bladder cancer in the EPIC cohort study

There is growing evidence of the protective role of the Mediterranean diet (MD) on cancer. However, to date no epidemiological study has investigated the influence of the MD on bladder cancer. We evaluated the association between adherence to the MD and risk of urothelial cell bladder cancer (UCC), according to tumor aggressiveness, in the European Prospective Investigation into Cancer and Nutrition (EPIC). The analysis included 477,312 participants, recruited from ten European countries between 1991 and 2000. Information from validated dietary questionnaires was used to develop a relative Mediterranean diet score (rMED), including nine dietary components. Cox regression models were used to assess the effect of the rMED on UCC risk, while adjusting for dietary energy and tobacco smoking of any kind. Stratified analyses were performed by sex, BMI, smoking status, European region and age at diagnosis. During an average follow-up of 11 years, 1,425 participants (70.9% male) were diagnosed with a first primary UCC. There was a negative but non-significant association between a high versus low rMED score and risk of UCC overall (HR: 0.84 [95% CI 0.69, 1.03]) and risk of aggressive (HR: 0.88 [95% CI 0.61, 1.28]) and non-aggressive tumors (HR: 0.78 [95% CI 0.54, 1.14]). Although there was no effect modification in the stratified analyses, there was a significant 34% (p = 0.043) decreased risk of UCC in current smokers with a high rMED score. In EPIC, the MD was not significantly associated with risk of UCC, although we cannot exclude that a MD may reduce risk in current smokers.

The Effects of Task-Set Switching On Concurrent Verbal Protocol

Concurrent verbal protocol (CVP) is a common usability testing and analysis technique that requires people to continuously vocalize their thoughts as they complete a task. Given the widespread use of concurrent verbal protocols in applied domains, it is surprising how little is known regarding concurrent verbal protocol’s effect on task performance. In the current series of studies, we examined how concurrent verbal protocols affected performance on two tasks that required users to frequently switch between cognitive strategies. Data revealed that CVP slowed down participants in comparison with participants who completed tasks in silence. The number of strategy changes that were required to complete a task did not affect this performance decrement. We conclude by discussing the limitations of the experiments reported here, and with practical advice for usability experts who use CVP in their own work.

Variety in vegetable and fruit consumption and the risk of gastric and esophageal cancer in the European Prospective Investigation into Cancer and Nutrition

Diets high in vegetables and fruits have been suggested to be inversely associated with risk of gastric cancer. However, the evidence of the effect of variety of consumption is limited. We therefore investigated whether consumption of a variety of vegetables and fruit is associated with gastric and esophageal cancer in the European Prospective Investigation into Cancer and Nutrition study. Data on food consumption and follow-up on cancer incidence were available for 452,269 participants from 10 European countries. After a mean follow-up of 8.4 years, 475 cases of gastric and esophageal adenocarcinomas (180 noncardia, 185 cardia, gastric esophageal junction and esophagus, 110 not specified) and 98 esophageal squamous cell carcinomas were observed. Diet Diversity Scores were used to quantify the variety in vegetable and fruit consumption. We used multivariable Cox proportional hazard models to calculate risk ratios. Independent from quantity of consumption, variety in the consumption of vegetables and fruit combined and of fruit consumption alone were statistically significantly inversely associated with the risk of esophageal squamous cell carcinoma (continuous hazard ratio per 2 products increment 0.88; 95% CI 0.79-0.97 and 0.76; 95% CI 0.62-0.94, respectively) with the latter particularly seen in ever smokers. Variety in vegetable and/or fruit consumption was not associated with risk of gastric and esophageal adenocarcinomas. Independent from quantity of consumption, more variety in vegetable and fruit consumption combined and in fruit consumption alone may decrease the risk of esophageal squamous cell carcinoma. However, residual confounding by lifestyle factors cannot be excluded.

Genetic susceptibility according to three metabolic pathways in cancers of the lung and bladder and in myeloid leukemias in nonsmokers

BACKGROUND

We chose a set of candidate single nucleotide polymorphisms (SNPs) to investigate gene-environment interactions in three types of cancer that have been related to air pollution (lung, bladder and myeloid leukemia).

PATIENTS AND METHODS

The study has been conducted as a nested case-control study within the European Prospective Investigation into Cancer and Nutrition cohort (409 cancer cases and 757 matched controls). We included never and ex-smokers. SNPs were in genes involved in oxidative stress, phase I metabolizing genes, phase II metabolizing genes and methylenetetrahydrofolate reductase (MTHFR).

RESULTS

The most notable findings are: GSTM1 deletion and bladder cancer risk [odds ratio (OR) = 1.60; 95% confidence interval 1.00-2.56]; CYP1A1 and leukemia (2.22, 1.33-3.70; heterozygotes); CYP1B1 and leukemia (0.47, 0.27-0.84; homozygotes); MnSOD and leukemia (1.91, 1.08-3.38; homozygotes) and NQO1 and lung cancer (8.03, 1.73-37.3; homozygotes). Other statistically significant associations were found in subgroups defined by smoking habits (never or ex-smokers), environmental tobacco smoke or gender, with no obvious pattern. When gene variants were organized according to the three main pathways, the emerging picture was of a strong involvement of combined phase I enzymes in leukemia, with an OR of 5 (1.63-15.4) for those having three or more variant alleles. The association was considerably stronger for leukemias arising before the age of 55.

Plasma and dietary carotenoid, retinol and tocopherol levels and the risk of gastric adenocarcinomas in the European prospective investigation into cancer and nutrition

Despite declining incidence rates, gastric cancer (GC) is a major cause of death worldwide. Its aetiology may involve dietary antioxidant micronutrients such as carotenoids and tocopherols. The objective of this study was to determine the association of plasma levels of seven common carotenoids, their total plasma concentration, retinol and α- and γ-tocopherol, with the risk of gastric adenocarcinoma in a case–control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC), a large cohort involving 10 countries. A secondary objective was to determine the association of total sum of carotenoids, retinol and α-tocopherol on GCs by anatomical subsite (cardia/noncardia) and histological subtype (diffuse/intestinal). Analytes were measured by high-performance liquid chromatography in prediagnostic plasma from 244 GC cases and 645 controls matched by age, gender, study centre and date of blood donation. Conditional logistic regression models adjusted by body mass index, total energy intake, smoking and Helicobacter pylori infection status were used to estimate relative cancer risks. After an average 3.2 years of follow-up, a negative association with GC risk was observed in the highest vs the lowest quartiles of plasma β-cryptoxanthin (odds ratio (OR)=0.53, 95% confidence intervals (CI)=0.30–0.94, P_trend=0.006), zeaxanthin (OR=0.39, 95% CI=0.22–0.69, P_trend=0.005), retinol (OR=0.55, 95% CI=0.33–0.93, P_trend=0.005) and lipid-unadjusted α-tocopherol (OR=0.59, 95% CI=0.37–0.94, P_trend=0.022). For all analytes, no heterogeneity of risk estimates or significant associations were observed by anatomical subsite. In the diffuse histological subtype, an inverse association was observed with the highest vs lowest quartile of lipid-unadjusted α-tocopherol (OR=0.26, 95% CI=0.11–0.65, P_trend=0.003). These results show that higher plasma concentrations of some carotenoids, retinol and α-tocopherol are associated with reduced risk of GC.

IGF-I, IGFBP-3 and breast cancer risk in women: The European Prospective Investigation into Cancer and Nutrition (EPIC)

Blood concentrations of insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3) have recently been associated with breast cancer risk, notably in women who developed breast cancer at a young age. Prospective studies published so far, however, were relatively small and odds ratio (OR) estimates imprecise. We present the results of a large prospective case-control study nested within the European Prospective Investigation into Cancer and Nutrition on total IGF-I, IGFBP-3 and breast cancer risk including 1081 incident cases of invasive breast cancer and 2098 matched control subjects. Increasing IGF-I and IGFBP-3 concentrations were associated with a significant increase in breast cancer risk in women who developed breast cancer after 50 years of age (highest vs lowest quintile OR 1.38 (95% confidence interval (CI) 1.02-1.86), P = 0.01, and 1.44 (95% CI 1.04-1.98), P = 0.01, respectively), but no relationship was observed in younger women (OR = 1.03 (95% CI 0.60-1.77), P = 0.81 for IGF-I, and OR = 0.92 (95% CI 0.50-1.70), P = 0.69 for IGFBP-3). There was, however, significant heterogeneity in the relationship of breast cancer with serum IGF-I and IGFBP-3 levels depending on the time interval between blood donation and tumor diagnosis. A reduction in breast cancer risk with increasing IGF-I concentrations was observed in cases with a diagnosis of cancer less than 2 years after blood donation, (OR = 0.76 (95% CI 0.57-1.03)), while an increase in risk was observed for women with a later diagnosis (above or equal to two years after blood collection, OR = 1.51 (95% CI 1.19-1.91)). A similar pattern was observed for IGFBP-3. This study confirms previous findings for an association of serum IGF-I and IGFBP-3 concentrations with breast cancer risk, particularly for women with a later diagnosis of cancer, but it does not support the hypothesis of an involvement of IGF-I in younger women.

Overweight, obesity and fat distribution in 50- to 64-year-old participants in the European Prospective Investigation into Cancer and Nutrition (EPIC)

OBJECTIVE

To describe anthropometric characteristics of participants of the European Prospective Investigation into Cancer and Nutrition (EPIC).

DESIGN

A cross-sectional analysis of baseline data of a European prospective cohort study.

SUBJECTS

This analysis includes study populations from 25 centres in nine European countries. The British populations comprised both a population-based and a 'health-conscious' group. The analysis was restricted to 83 178 men and 163 851 women aged 50-64 years, this group being represented in all centres.

METHODS

Anthropometric examinations were undertaken by trained observers using standardised methods and included measurements of weight, height, and waist and hip circumferences. In the 'health-conscious' group (UK), anthropometric measures were predicted from self-reports.

RESULTS

Except in the 'health-conscious' group (UK) and in the French centres, mean body mass index (BMI) exceeded 25.0 kg m-2. The prevalence of obesity (BMI> or =30 kg m(-2)) varied from 8% to 40% in men, and from 5% to 53% in women, with high prevalences (>25%) in the centres from Spain, Greece, Ragusa and Naples (Italy) and the lowest prevalences (<10%) in the French centres and the 'health-conscious' group (UK). The prevalence of a large waist circumference or a high waist-to-hip ratio was high in centres from Spain, Greece, Ragusa and Naples (Italy) and among women from centres in Germany and Bilthoven (The Netherlands).

CONCLUSIONS

Anthropometric measures varied considerably within the EPIC population. These data provide a strong base for further investigation of anthropometric measures in relation to the risk of chronic diseases, especially cancer.

Biomonitoring study of people living near or working at a municipal solid-waste incinerator before and after two years of operation

The authors conducted a biomonitoring study in the town of Mataró, Spain, of 104 subjects who lived near (i.e., within 0.5-1.5 km) an incinerator, 97 subjects who lived far (i.e., within 3.5 km-4.0 km) from an incinerator, and 17 workers at a new municipal solid-waste incinerator. The study commenced before the incinerator started functioning in 1995, and 2 y later (1977) the authors undertook the final part of the study. Dioxins, furans, and polychlorinated biphenyls were studied in pooled blood samples (n = 22), and individual blood and urine samples were analyzed for the detection of lead, chromium, cadmium, and mercury. In 1995, dioxin blood levels were low-both among those living close to the incinerator (mean = 13.5 ng international-dioxin toxic equivalents/kg fat) and among those living far away (mean = 13.4 ng international-dioxin toxic equivalents/kg fat). In 1997, dioxin and polychlorinated biphenyl levels had increased in both groups of residents by approximately 25% and 12%, respectively. (The increase in dioxin levels was about 10% when the authors took into account the mean of two repeated quality-control analyses.) Blood lead levels decreased, but no difference was observed for chromium, cadmium, and mercury. Minimal changes were seen among workers. Given the low dioxin stack emissions from this plant (mean = 2.5-0.98 ng international-dioxin toxic equivalents/m3) and that the blood dioxin levels did not depend on distance of residence from the incinerator, it would appear unlikely that the small increase in dioxin blood levels resulted from the incinerator's emissions.

High intake of specific carotenoids and flavonoids does not reduce the risk of bladder cancer

An analysis of a previously completed Spanish multicentric case-control study of bladder cancer was carried out using new available data on the contents in foods of specific carotenoids (alpha-carotene, beta-carotene, lutein, and lycopene) and flavonoids (quercetin, kaempferol, myricetin, and luteolin) to investigate the relationship of these phytochemicals with bladder cancer. The study included 497 cases first diagnosed with bladder cancer, 547 neighborhood controls, and 566 hospitals controls, matched by gender, age, area of residence, and hospital. Usual food intake was estimated using a dietary history questionnaire administered by trained interviewers. None of the specific carotenoids and none of the specific flavonoids have been found to be significantly associated with bladder cancer risk in this analysis. The adjusted odds ratios for subjects in the highest quartile of intake with respect to subjects in the lowest quartile were 1.36 (95% confidence interval = 0.94-1.95) for total carotenoid intake and 1.23 (95% confidence interval = 0.85-1.79) for total flavonoid intake. The results of this study does not support the hypothesis that intake of specific carotenoids and flavonoids is protective against bladder cancer risk.

Environmental tobacco smoke interference in the assessment of the health impact of a municipal waste incinerator on children through urinary thioether assay

The urinary elimination of thioethers urinary thioethers (UT) was studied in 83 schoolchildren living in two different areas of the city of Mataró, with special attention paid to the influence of a waste incinerator and of the smoking habits of their parents. The mean UT values were 8.79+/-3.23 and 7.52+/-3.23 mmol/mol creatinine in the area close to the incinerator (A1) and in the area far away from it (A2) respectively (statistically n.s.). Children exposed to environmental tobacco smoke (ETS) at home presented increased levels of UT (8.60+/-3.11 vs 5.93+/-3.22 mmol/mol creatinine; P=0.002). Considering the two exposures together (waste incinerator and ETS), no differences were found between the two areas studied (A1 and A2) in non-exposed (ETS) children, whereas slight differences were found when comparing highest ETS exposed children from the two areas (10. 18+/-2.70 vs 8.00+/-3.42 mmol/mol creatinine; P=0.04). Exposure to ETS could affect health more than pollutants from a waste incinerator and may interfere with non-selective assays such as urinary thioethers.

Intake of specific carotenoids and flavonoids and the risk of lung cancer in women in Barcelona, Spain

Newly available data of a case-control study of lung cancer in women in Spain were analyzed to assess the relationship with the intake of specific carotenoids (alpha-carotene, beta-carotene, lutein, and lycopene) and flavonoids (quercetin, kaempferol, myricetin, and luteolin). The study included 103 cases and 206 hospital controls, matched by age and residence. Usual food intake was estimated through a food-frequency questionnaire. With adjustment for smoking habit and vitamin E, vitamin C, and total flavonoid intake, no association was found for the intake of alpha-carotene, beta-carotene, or lutein. The odds ratio (95% confidence interval) for women in the highest tertile of lycopene intake with respect to the lowest was 0.56 (0.26-1.24), with p for trend = 0.15. A nonsignificant association was observed for the highest vs. lowest tertile intake of kaempferol (odds ratio = 0.51, 95% confidence interval = 0.22-1.17), with p for trend = 0.10, after adjustment for smoking and vitamin E, vitamin C, and total carotenoid intake. No protective effect was observed for quercetin or luteolin or for total flavonoid intake.

Intake of specific carotenoids and flavonoids and the risk of gastric cancer in Spain

OBJECTIVES

To investigate the relationship between gastric cancer and the intake of specific carotenoids (alpha-carotene, beta-carotene, lutein, and lycopene) and flavonoids (quercetin, kaempferol, myricetin, and luteolin) using new data on their concentration in foods.

METHODS

Case-control study carried out in Spain that included 354 cases of gastric cancer and 354 controls, matched by age, gender, area of residence and hospital. Usual food intake was assessed using a dietary history questionnaire.

RESULTS

In a multivariate model adjusted for several dietary factors, no association was found between intake of any of the studied carotenoids and the risk of gastric cancer. The adjusted OR of gastric cancer for the highest quartile of total flavonoid intake versus the lowest quartile was 0.44 (95 percent confidence interval [CI] = 0.25-0.78; P for trend = 0.003). Kaempferol intake was found to be protective (OR = 0.48; CI = 0.26-0.88; P for trend = 0.04) comparing the highest versus the lowest quartile of intake. A trend toward lower risk of stomach cancer with higher intake of quercetin was also found.

CONCLUSIONS

The results of this study support the hypothesis that the well-established protective effect of fruit and vegetables against gastric cancer could, in part, be due to the presence of flavonoids.

Multicenter case-control study of exposure to environmental tobacco smoke and lung cancer in Europe

BACKGROUND

An association between exposure to environmental tobacco smoke (ETS) and lung cancer risk has been suggested. To evaluate this possible association better, researchers need more precise estimates of risk, the relative contribution of different sources of ETS, and the effect of ETS exposure on different histologic types of lung cancer. To address these issues, we have conducted a case-control study of lung cancer and exposure to ETS in 12 centers from seven European countries.

METHODS

A total of 650 patients with lung cancer and 1542 control subjects up to 74 years of age were interviewed about exposure to ETS. Neither case subjects nor control subjects had smoked more than 400 cigarettes in their lifetime.

RESULTS

ETS exposure during childhood was not associated with an increased risk of lung cancer (odds ratio [OR] for ever exposure = 0.78; 95% confidence interval [CI] = 0.64-0.96). The OR for ever exposure to spousal ETS was 1.16 (95% CI = 0.93-1.44). No clear dose-response relationship could be demonstrated for cumulative spousal ETS exposure. The OR for ever exposure to workplace ETS was 1.17 (95% CI = 0.94-1.45), with possible evidence of increasing risk for increasing duration of exposure. No increase in risk was detected in subjects whose exposure to spousal or workplace ETS ended more than 15 years earlier. Ever exposure to ETS from other sources was not associated with lung cancer risk. Risks from combined exposure to spousal and workplace ETS were higher for squamous cell carcinoma and small-cell carcinoma than for adenocarcinoma, but the differences were not statistically significant.

CONCLUSIONS

Our results indicate no association between childhood exposure to ETS and lung cancer risk. We did find weak evidence of a dose-response relationship between risk of lung cancer and exposure to spousal and workplace ETS. There was no detectable risk after cessation of exposure.

Blood levels of polychlorinated dibenzodioxins, polychlorinated dibenzofurans and polychlorinated biphenyls in the general population of a Spanish Mediterranean city

Polychlorinated dibenzodioxins (PCDDs), Polychlorinated dibenzofurans (PCDFs) and Polychlorinated biphenyls (PCBs) are among the most toxic environmental pollutants. We determined blood levels of these compounds in a population sample of the city of Mataró, Spain. Blood samples were drawn from a randomly selected sample of 198 subjects, of both genders, aged 18 to 69 years. These samples were pooled into 10 groups for laboratory analysis. For males, total level of PCDDs was 505.7 ppt, of PCDFs was 26.7 ppt, and the international toxic equivalent (I-TEQ) was 12.5. For females the levels were 739 ppt, 28.8 ppt and 14.71-TEQ, respectively. The most important contributors to the total I-TEQ were HexaCDD, PentaCDD and PentaCDF. The blood concentration of total PCBs was 2.02 mg/l in males, and 1.58 mg/l in females. Levels of PCDDs, PCDFs and PCBs increased by age in both sexes. The levels of PCDDs and PCDFs in residents of this Mediterranean city are among the lowest observed in industrialized countries.

Detection of animal tissue thickness using simple vertical electric sounding (VES)

Tetrapolar linear arrays are commonly used in geophysics to explore the vertical distribution of resistivity values in a geological section of a specific point on the earth. This technique, known as vertical electric sounding (VES), uses different electrode configurations. For our experiments, we utilized its more popular variation, called the Schlumberger arrangement (VES-Sch), to make measurements on a system composed of pig backfat placed on a conductive paste that simulates the longitudinal resistivity of muscle. The results show that the physical and mathematical principles involved in VES-Sch are applicable to animal structures such as that composed of skin and fat and that it could be possible, for instance, to determine the thickness of the subcutaneous fat. This might be useful in studies of body composition and to evaluate nutritional status. In the future, an electrical impedance tomograph (EIT) of low frequency could be used to obtain static images using this approach.

Lung cancer and cigarette smoking in women: a case-control study in Barcelona (Spain)

A case-control study on lung cancer and the habit of cigarette smoking was carried out in Barcelona (Spain). Cases were 103 women newly diagnosed with primary lung cancer in 10 hospitals from the study area. Histologic confirmation was given in 101 cases, of which 53 were adenocarcinoma, 19 squamous-cell carcinoma, 9 small-cell carcinoma and 20 other types. Two controls per case were selected, matched by age, residence and hospital. Compared with the never-smokers, the odds ratios (OR), with corresponding 95% confidence intervals (CI), were 1.61 (0.4 to 6.9) for ex-smokers and 3.61 (1.6 to 8.3) for current smokers. The risk of lung cancer showed a good dose-response relationship with duration of the habit, average number of cigarettes smoked daily and cumulative cigarette consumption. The risk of lung cancer increased by 62% for each 10 pack-years. Depth of inhalation also showed a remarkable effect, independently of the intensity of the habit. Although mortality and incidence rates of lung cancer among women in Spain are lower than in other developed countries, the risk of lung cancer is that which would be expected according to the pattern of the smoking habit in Spanish women.

Prevalence of exercise-induced airway narrowing in schoolchildren from a Mediterranean town

A cross-sectional study was carried out on a random sample of 2,216 schoolchildren 9 to 14 yr of age to determine the prevalence of exercise-induced airway narrowing (EIAN) in a Mediterranean town (Mataró). A complementary case-control study measured the association between EIAN and respiratory symptoms. A free-running test was performed during school time. Peak expiratory flow rate (PEFR) was measured at rest and at 2, 5, 10, and 15 min after exercise. A total of 136 of 2,056 satisfactory runs showed a decrease of PEFR equal to or higher than 15% at each of these times after exercise. Five more children developed wheezing during running and were considered to have EIAN. Prevalence of EIAN was 6.9% (95% CI = 5.9 to 7.9). Prevalence decreased progressively with age. No sex difference was found. In the case-control study a questionnaire of respiratory symptoms was applied to the mothers of hyperresponsive children, as well as to two matched control subjects for each case. Questionnaire analysis showed a strong association between EIAN and respiratory symptoms or rhinitis. Association with bronchitis before 2 yr of age and parental asthma was less but significant.

Prevalence of piroplasmosis in equines in the Colombian province of Cordoba

Eighty-two equine sera from 13 farms in northern Colombia were examined for antibodies to Babesia caballi and B. equi using the complement fixation (CF) and the indirect fluorescent antibody (IFA) test. Seroreactors to both piroplasms were present on all farms. The IFA test indicated a prevalence of 90% for B. caballi and 94% for B. equi. The CF test detected antibodies to B. caballi in 41% and to B. equi in 65% of the animals. The prevalence of seroreactors in different age groups revealed a significant decline in CF antibodies to B. caballi in animals older than three years. IFA titres for both Babesia spp. gradually declined with increasing age of the animals but were still present in most animals of the oldest age group (over nine years old). Anocentor nitens was found on all farms whereas Amblyomma cajennese was found only on two farms located on the coast.

Social and environmental factors influencing mother-infant separation-reunion in squirrel monkeys

Sixteen squirrel monkey mother and infant dyads were housed in groups of two. They were separated and then immediately reunited in their familiar home cage or in a novel environment, either in conjunction with the second mother-infant dyad, or as a single manipulated pair. Behavioral observations of both dyads were made during the 30-min period following these manipulations; blood samples were then taken for cortisol assay. Mothers' locomotor activity increased when a single dyad was manipulated in the home cage and decreased in the novel environment where proximity between the pairs increased. Cortisol levels varied significantly across conditions, with mothers and infants responding to different stimuli. Mothers responded primarily to social disruption, including separation from the other dyad, and infants responded most clearly to novelty and separation from the other dyad. No significant differences were observed over base levels when both mother and infant pairs were reunited in the home cage, indicating that changes were not due to the disturbance involved in the separation procedure.

Behavioral and hormonal responses to separation in infant rhesus monkeys and mothers

Effects of social stimuli on behavioral and physiological responses were examined in infant rhesus monkeys at 4 and 9 months of age. Infants and mothers were removed from the social group and housed as dyads. Following this period, infants were removed and separated under four counterbalanced conditions: (a) totally isolated--placed in a holding cage for 24 hr; (b) mother present, no contact--housed in a single cage in view of their mother, no contact; (c) mother present, contact--similar to above, with mother in proximity to the infant; and (d) peer present--separated but in proximity to a peer. In the first experiment, the infants rarely vocalized when totally isolated but showed high rates of vocalization in the presence of the mother, both with and without contact. In the mother-present conditions, they failed to show a plasma cortisol response. In contrast, totally isolated infants showed a significant elevation in plasma cortisol. At 9 months of age, these infants were separated for 3 days under two different conditions: mother present and totally isolated. Once again, the infants that were totally isolated showed little vocalization but significant elevations in plasma cortisol. In contrast, infants separated in the presence of their mothers showed high vocalization rates but no cortisol response. The concepts of protest and despair are discussed as they relate to behavioral and physiological differences observed following different separation paradigms.

Influence of social variables on the biobehavioral response to separation in rhesus monkey infants

Effects of social stimuli on behavioral and physiological responses to separation were examined in 4-month-old rhesus monkeys. Infants were removed from their social group under 3 counterbalanced conditions: (1) infant totally isolated from its familiar physical and social environment and placed alone in a cage for 4 days; (2) "mother in"--housing the infant in a single cage in front of its social group with mother remaining in the group; (3) "mother out"--similar situation, except that mother was removed from the group during separation. Infant behavior was recorded, and, at selected times during separation, a blood sample was obtained for analysis of plasma cortisol. Infants rarely vocalized when totally isolated, but showed high vocalization and movement in the presence of their social groups. Vocalization was transiently higher in mother-out condition than in mother-in condition. Infants never showed signs of depression. Plasma cortisol response did not differentiate between groups. Animals showed significantly high levels of plasma cortisol 3 hours following separation. These data indicate that the responses of the infant following separation are attempts to produce effective coping responses. The concepts of "protest" and "despair" are discussed as they relate to behavioral differences observed following different separation paradigms.

Sex differences in biobehavioral responses to conflict in a taste aversion paradigm

A conditioned aversion to a novel milk solution was produced, and animals were then reexposed to milk while nondeprived (low conflict) or following a 72-hr food and water deprivation regimen (high conflict). No sex differences occurred if animals were nondeprived throughout testing. However, if deprived during the interval between conditioning and reexposure, sex differences in both behavior and adrenocortical responses occurred: (1) Presession corticoid levels of females were higher than those of males. (2) On the first reexposure day, females showed a suppression of plasma corticosterone below presession levels, while males maintained elevated or increased corticosterone levels. (3) On the second reexposure day, when no longer deprived, males showed a marked suppression of intake compared to females, and females subsequently recovered to pretoxicosis intake levels faster than males. (4) Gonadectomy eliminated these sex differences. While ovariectomized females continued to resemble intact females in both behavioral and hormonal responses, castrated males exhibited a corticoid suppression on the first reexposure day, and subsequently recovered to pretoxicosis intake levels at the same rate as females.

Cortisol responses under different housing conditions in female squirrel monkeys

Adult female squirrel monkeys were housed in a group, in pairs or individually. Plasma levels of cortisol obtained under basal and stress conditions once weekly for four weeks were significantly lower in pair-housed females than in those living in a social group or individually. The increment in cortisol levels after stress (induced by handling and ether anesthesia) also was smaller in females housed in pairs. The cortisol values of the pair-housed females were positively correlated with those of their partners. Basal cortisol levels in the group-living females showed a significant rank-order correlation with dominance status. This indicated that social interactions in group-living animals can influence cortisol levels in a complex manner, either increasing or decreasing them. The relatively lower pituitary--adrenal activation when a single partner was present also indicated that the social environment can affect an individual's general level of arousal and subsequently alter the response to stressful stimuli.

Non-histone chromosomal proteins from virus-transformed and untransformed 3T3 mouse fibroblasts

A peak in the non-histone chromosomal protein polyacrylamide gel electrophoresis profiles has been detected which is higher in log phase 3T3 and 3T3/SV40 cells than in density-inhibited 3T3 cells. Radioactive incorporation is substantially higher into this peak in log phase 3T3 than in 3T3/SV40 and density-inhibited 3T3 cells. Reversion of 3T3/SV40 cells with dibutyryl cyclic AMP and theophylline produces increased radioactive incorporation into the peak. Electrophoresis of non-histone chromosomal proteins extracted at different stages of the cell cycle in density inhibited 3T3 cells following serum stimulation shows a cyclic variation in the amount of this peak with maximum accumulation in late G1. In contrast the height of an equivalent peak in synchronously growing 3T3/SV40 cells remains constant throughout the cell cycle. It is postulated that the protein(s) of this peak may have a regulatory role in cell growth.