Israel Medical Association Journal

Background: In recent years several reports have been published describing dogs’ ability to detect, by scent, patients with cancer. This ability is based on the sniffing of volatile organic elements that are secreted by malignant cells, react to them. 

Objectives: To evaluate the ability of trained dogs to detect (i) breast cancer cell cultures (MCF7) compared to the control pseudo-normal keratinocyte cell line (HaCaT), and then (ii) melanoma (BG) and (iii) type 2 epithelial lung carcinoma (A549) malignant cell cultures to which they were not previously exposed in the course of their training.

Methods: Cell cultures were prepared in a standard manner. Two Belgian Shepherd dogs were trained and then tested in a single-blind test (for dogs and trainers) on their ability to detect the "target specimen," a MCF7 breast cancer cell culture. Following this, the ability of the dogs to detect cancer cell cultures that they were not previously exposed to (i.e., A549, BG) was tested. In each test round, four specimens placed in identical blocks were arranged in a line with one meter between them: one target specimen (MCF7, A549, BG), two control specimens (HaCaT), and a sample containing cell culture medium only.

Results: The two dogs picked out all the target specimens of MCF7 breast cancer cell cultures that they were trained to detect (10/10) as well as all the target specimens that they were not previously exposed to [A549 (5/5) and BG (5/5)], but did not pick out the control specimens or the cell culture medium. Thus, the sensitivity, specificity, and positive and negative predictive values for both dogs were 100%.

Conclusions: The results of this study support the assumption that cancer cells have a unique odor pattern, and that this odor pattern is common to different types of cancer.

 

Background: Several studies have identified associations between low vitamin D concentrations and risk of upper respiratory infections (URI). T lymphocytes have a major anti-viral role, are affected by vitamin D metabolism, and may mediate the link between vitamin D and URIs. Competitive swimmers have a relatively high rate of URIs, alongside a high prevalence of low vitamin D concentration. 

Objectives: To examine the associations linking T cell receptor excision circles (TREC, markers of thymus activity), circulating 25(OH)D concentrations and the effect of vitamin D supplementation, and URI symptoms in young competitive swimmers.

Methods: We tested 82 adolescent swimmers for serum 25(OH)D and TREC concentrations and found that 55 had vitamin D insufficiency. Randomized supplementation of either vitamin D3 or placebo was given for 12 winter weeks. URI symptoms were recorded weekly. The associations between TREC copy numbers, vitamin D and URI burden were examined.

Results: TREC concentrations decreased with the participants’ age (r = -0.346, P = 0.003), with no significant between-gender difference. TREC concentrations did not materially differ among subjects with normal, insufficient or deficient vitamin D status, and were not affected by vitamin D supplementation. No significant correlations were found between TREC levels or their changes during the study period, and mean URI severity or duration. 

Conclusions: Thymus activity, represented by higher TREC levels, was not related to vitamin D concentrations or status, and was not affected by vitamin D supplementation in adolescent swimmers. TREC concentrations were not associated with URI severity or duration in this population.

 

Background: Isolation of methicillin-resistant Staphylococcus aureus (MRSA) in healthy individuals is not common in Israel. In our hospital, about 30% of MRSA isolates were SCCmec types IV and V.

Objectives: To identify the demographic and clinical characteristics of patients carrying MRSA SCCmec type IV or V, and to compare them with each other and with those of patients with SCCmec types I-III.

Methods: We conducted a case-control study that included 501 patients from whom MRSA was isolated: 254 with SCCmec type I, II, or III, and 243 isolates from SCCmec types IV or V. 

Results: MRSA was isolated from surveillance cultures in 75% of patients and from a clinical site in 25%. The majority of our study population was elderly, from nursing homes, and with extensive exposure to health care. First, we compared characteristics of patients identified through screening. Statistically significant predictors of SCCmec V vs. IV were Arab ethnicity (OR 7.44, 95%CI 1.5–37.9) and hospitalization in the year prior to study inclusion (OR 5.7, 95%CI 1.9–16.9). No differences were found between patients with SCCmec types I-III and patients with SCCmec type IV or V. Analysis of the subset of patients who had clinical cultures yielded similar results. 

Conclusions: SCCmec types IV and V were common in the hospital setting although rare in the community. It seems that in Israel, SCCmec IV and V are predominantly health care-associated MRSA. 

 

Background: Childhood attention deficit hyperactivity disorder (ADHD) is a chronic health problem with significant risk for long-term morbidity in adulthood.

Objectives: We examined long-term outcomes of ADHD in a population-based sample of childhood ADHD cases prospectively assessed as adults.

Methods: Long-term outcomes for 70 adults who were diagnosed with ADHD during childhood were examined and compared with data on the general population.

Results: Most subjects admitted to persistence of ADHD-related symptoms in adulthood, despite discontinuation of regular medical treatment and follow-up. Areas most severely affected by past and ongoing symptoms included driving performance and incidence of motor vehicle accidents, and rates of marriage stability over time. Relatively unaffected were occupational and academic achievements and military service. 

Conclusions: There is a need for outreach and better services for adults who were previously diagnosed with ADHD. 

 

Background: Stroke is a leading cause of death and disability worldwide. The risk factors for stroke overlap those for cardiovascular disease. Atrial fibrillation (AF) is a particularly strong risk factor and is common, particularly in the elderly. Maccabi Healthcare Services (MHS) has maintained a vascular registry of clinical information for over 100,000 members, among them patients with heart disease and stroke. 

Objectives: To determine the prevalence of stroke in MHS, and whether the association of AF and stroke, along with other risk factors, in the Maccabi population is similar to that in published studies.

Methods: Data on stroke and AF patients aged 45 and older were collected from the database for the year 2010, including age, previous transient ischemic attack (TIA), body mass index (BMI), prior myocardial infarction (MI), diabetes, hypertension, anticoagulation and dyslipidemia. A cross-sectional analysis was used to estimate stroke prevalence by AF status. A case-control analysis was also performed comparing a sample of stroke and non-stroke patients. This permitted estimation of the strength of associations for atrial fibrillation and various other combinations of risk factors with stroke. 

Results: Stroke prevalence ranged from 3.5 (females, age 45–54 years) to 74.1 (males, age 85+) per thousand in non-AF members, and from 29 (males, age 45–54) to 165 (males, age 85+) per thousand for patients with AF. AF patients had significantly more strokes than non-AF patients in all age groups. Stroke prevalence increased with age and was significantly higher in males. Multivariable analysis revealed that male gender, increasing age, AF, hypertension, diabetes, and history of TIA were highly significant risk factors for stroke. In addition, for males, dyslipidemia and prior MI were moderately strong risk factors. 

Conclusions: Analysis of the MHS vascular database yielded useful information on stroke prevalence and association of known risk factors with stroke, which is consistent with the epidemiological literature elsewhere. Further analysis of health fund data could potentially provide useful information in the future. 

 

Background: Obstructive sleep apnea (OSA) is a common health problem with an estimated prevalence of 4% among men, many of whom are undiagnosed and untreated. 

Objectives: To compare demographic characteristics, health profiles, risk factors, and disease severity in Arab and Jewish men with OSA syndrome.

Methods: In this cross-sectional study we retrospectively analyzed clinical data from the medical files of men ≥ 22 years old who were referred to the Rambam Medical Center sleep clinic during the period 2001–2009 with a suspected diagnosis of OSA. OSA severity was measured using the apnea-hypopnea index (AHI). Categorical variables were compared using the chi-square test. Relations between OSA severity and a set of independent risk factors were assessed by linear regression analysis.

Results: A total of 207 men were included (39 Arabs, 19%; 168 Jews, 81%). Arab participants were younger than their Jewish counterparts (45.5 ± 8.9 years vs. 49.8 ± 11.8, P = 0.04) and their body mass index (BMI) was higher (33.1 ± 5.1 vs. 30.0 ± 4.4, P = 0.001). OSA severity (AHI score) was higher among Arab men, with low, medium and high severity scores seen in 10%, 33% and 56% of Arab men vs 35%, 29% and 37% of Jewish men, respectively [T(198)=2.39, P = 0.02]. Mean blood oxygen saturation was comparable.

Conclusions: Arab men presenting for evaluation of sleep apnea harbored more severe OSA symptoms, were younger, and had higher BMI compared to Jewish men. Since OSA syndrome evolves for several years until it becomes severe, these findings suggest that Arab men seek medical assistance later than Jewish men with OSA.

 

Background: Anemia confers an adverse prognosis in patients with ST-elevation myocardial infarction (STEMI). Several mechanisms have been implicated in the etiology of anemia in this setting, including inflammation, blood loss, and the presence of comorbidities such as renal failure.

Objectives: To evaluate the adequacy of bone marrow response as potentially reflected by elevation in blood and reticulocyte counts.

Methods: Consecutive men with STEMI who underwent primary percutaneous intervention within 6 hours of symptom onset and who presented to our catheterization laboratory during a 36 month period were included in the study. The cohort was divided into quartiles according to hemoglobin concentration, and differences in clinical and laboratory characteristics between the groups were evaluated.

Results: A total of 258 men with STEMI were recruited, 22% of whom suffered from anemia according to the World Health Organization classification (hemoglobin < 13 g/dl). Men in the lowest quartile of hemoglobin concentration presented with significantly lower white blood cell and platelet counts (9.6 ± 2.9 vs. 12.6 ± 3.6 x103/µl, P < 0.001) and (231 ± 79 vs. 263 ± 8 x103/µl, P < 0.01), respectively, despite higher inflammatory biomarkers (C-reactive protein and fibrinogen) compared with patients in the upper hemoglobin concentration quartile. Reticulocyte production index was not significantly higher in anemic patients with a value of 1.8, 1.4, 1.5 and 1.6 in the ascending hemoglobin quartiles, respectively (P = 0.292). 

Conclusions: Anemic men with STEMI have relatively lower leukocyte and platelet counts as well as a reduced reticulocyte count despite higher inflammatory biomarkers. These findings might suggest inadequate bone marrow response. 

 

Background: Cardiac resynchronization therapy (CRT) is a non-pharmacological option for patients with heart failure and interventricular dyssynchrony. Elevated red cell distribution width (RDW) reflects higher size and heterogeneity of erythrocytes and is associated with poor outcome in patients with chronic heart failure. 

Objectives: To examine the association between RDW levels and outcomes after CRT implantation.

Methods: We conducted a cohort analysis of 156 patients (126 men, median age 69.0 years) who underwent CRT implantation in our institution during 2004–2008. RDW was measured at three time points before and after implantation. Primary outcome was defined as all-cause mortality, and secondary outcome as hospital re-admissions. We investigated the association between RDW levels and primary outcome during a median follow-up of 61 months.

Results: Ninety-five patients (60.9%) died during follow-up. Higher baseline RDW levels were associated with all-cause mortality (unadjusted HR 1.35, 95%CI 1.20–1.52, P < 0.001). On multivariate analysis adjusted for clinical, electrocardiographic and laboratory variables, baseline RDW levels were associated with mortality (HR 1.33, 95%CI 1.16–1.53). RDW levels 6 months and 12 months post-implantation were also associated with mortality (HR 1.22, 95%CI 1.08–1.38, P = 0.001; and HR 1.15, 95%CI 1.01–1.32, P = 0.02, respectively). Patients who were re-admitted to hospital during follow-up (n=78) had higher baseline RDW levels as compared to those who were not (14.9%, IQR 14.0, 16.0% vs. 14.3%, IQR 13.7, 15.0%, respectively, P = 0.03). 

Conclusion: An elevated RDW level before and after CRT implantation is independently associated with all-cause mortality.