Meta-analysis of Hodgkin's disease among farmers

OBJECTIVES: This study examined the association between Hodgkin's disease and farming. METHODS: A series of meta-analyses of peer-reviewed studies was performed, using 30 studies published between 1981 and 1998. Prior to the meta-analyses, all the studies were reviewed and evaluated for heterogeneity and publication bias. Combined relative risks (RR) were calculated using the random effect model. RESULTS: The combined RR was 1.25 [95% confidence interval (95% CI) 1.11-1.42] for all the studies, and 1.08 (95% CI 0.91-1.29) for the studies involving female farmers. Significant heterogeneity among the studies was detected, and a stratified analysis was carried out by study design, country of study, and time of publication. Significantly elevated RR values were obtained for the case-referent studies (odds ratio 1.53, 95% CI 1.18-1.98) and proportionate mortality studies (PMR)(PMR 1.18, 95% CI 1.02-1.36). A decrease in risk was eminent in the more recent studies. CONCLUSIONS: The findings suggest that male farmers have a slightly elevated risk of developing Hodgkin's disease. No specific etiologic exposure was identified, but exposures commonly experienced by farmers (infectious microorganisms, herbicides and insecticides) may contribute to the occurrence of the disease.     

Association between occlusal force distribution in implant overdenture prostheses and residual ridge resorption

This study aimed to investigate residual ridge resorption (RRR) of anterior and posterior maxillary and mandibular edentulous ridges, in patients treated with mandibular implant overdentures (IOD) and compare with conventional complete denture (CD) wearers, and to determine at each location, the association of RRR with the occlusal forces distribution and other patients’ variables. The anterior and posterior RRR of IOD (six males, 17 females) and CD (12 males, 11 females) groups were determined using baseline and follow‐up dental panaromic radiographs (DPT) (mean intervals 4 ± 1·8 years). The bone ratios were calculated using proportional area: anatomic to fixed reference areas and mean difference of ratios between the intervals determined RRR. The ridge locations included anterior and posterior maxillary and posterior mandibular arches. The T‐Scan III digital occlusal system was used to record anterior and posterior percentage occlusal force (%OF) distributions. There were significant differences in anterior and posterior %OF between treatment groups. Two‐way anova showed RRR was significant for arch locations (P = 0·005), treatment group (IOD versus CD) (P = 0·001), however, no significant interaction (P = 0·799). Multivariate regression analyses showed significant association between RRR and %OF at anterior maxilla (P = 0·000) and posterior mandible (P = 0·023) and for treatment groups at posterior maxilla (P = 0·033) and mandibular areas (P = 0·021). Resorption was observed in IOD compared to CD groups, with 8·5% chance of less resorption in former and 7·8% in the latter location. Depending on arch location, ridge resorption at various locations was associated with occlusal force distribution and/or treatment groups (implant prostheses or conventional complete dentures).     

Long-term benefits of aggressive treatment for primary colorectal cancer

The long-term follow up of 128 colorectal cancer patients is reported. Seventy-nine percent (101/128) of the patients had curative resections: 70 patients had radical lymphadenectomies with wide removal of tumor-adjacent nodes, and 31 patients had standard resections. The 5-year overall survival rates for Dukes' stage B and C patients and for all rectosigmoid cancer patients significantly favored radical resection (60% vs. 38%, 57% vs. 29%, respectively, P < 0.05). Tumor-free survival rates were also higher after radical lymphadenectomy but did not reach statistical significance. Eleven percent (14/128) of the patients required multiorgan resections, and/or preoperative radiation to render fixed cancers resectable, and these patients had a 10-year tumor-free survival rate of 45%, compared to zero % 5-year survival for the 27 patients who underwent palliative procedures (P < 0.01). These results confirm that many colorectal cancer patients will be cured with aggressive treatment and they support the need for a controlled trial for evaluation of lymphadenectomy for this disease. © 1996 Wiley-Liss, Inc.     

Evaluation of safety orientation and training programs for reducing injuries in the plumbing and pipefitting industry

Construction workers are at increased risk for fatal and non-fatal injuries. This study examined the effectiveness of employee orientation and training in reducing injuries among plumbers and pipefitters. We searched the Occupational Safety and Health Administration's "recordable" injury data and "documentable" safety and training records for six plumbing and pipefitting employers in northwestern Ohio. During the period 1996 to 1998, 133 injuries were recorded with the duration of 2,541,432 working hours. The most common types of injuries were cuts, lacerations, and abrasions. The majority of injuries resulted from workers being struck by objects. The injury rate was significantly higher for small companies and longer working hours. No difference was found between traveling and local workers. Seventy-five percent of workers received safety orientations on injury prevention. Among workers who received safety orientations, only 3.4% experienced injuries, compared with 11.1% of workers without orientations. Safety orientations were associated with a significant reduction in injuries (odds ratio, 0.23; 95% confidence interval, 0.15 to 0.35). Proper safety orientation and training could reduce the risks for occupational injuries in construction workers.     

Is there an association between passive smoking and breast cancer?

Recent epidemiological studies have suggested passive smoking as possible risk factors in breast cancer etiology. However, the evidence is not conclusive. We conducted a meta-analysis of the risk of breast cancer associated with passive smoking. Eleven studies were identified through Medline, Cancer Abstracts and abstract presented at related scientific meetings. Combined estimates of relative risks (RR) were calculated using fixed and random effect models. Significant heterogeneity was detected among the studies (² = 34.6, p < 0.01). The combined estimate of RR for ever exposure to passive smoking was 1.41 (95% confidence interval (CI): 1.14–1.75). The combined estimate for published studies was 1.43 (95% CI: 1.10–1.85). Only two studies reported significant dose-response relation between level of passive smoking and premenopausal breast cancer. Our analysis suggests a possible weak association between passive smoking and breast cancer. More studies are needed to establish whether the observed association is causal.     

The feasibility of using histologic placental sections to predict newborn nucleated red blood cell counts

OBJECTIVE: To determine the feasibility of using calculated nucleated red blood cell (RBC) counts from histologic placental slides to predict newborn nucleated RBC counts. METHODS: This retrospective study compared absolute nucleated RBC counts from 24 newborns, diagnosed with fetal distress in labor, with counts calculated from their histologic placental slides. A simple linear regression model was tested with newborn nucleated RBC counts as the dependent variable and calculated placental nucleated RBC counts as the independent variable. RESULTS: The mean +/- standard deviation newborn nucleated RBC count was 4.81 x 10(9) +/- 5.46 x 10(9)/L compared with 1.37 x 10(9) +/- 1.78 x 10(9)/L calculated from placental sections. These data were normalized by logarithmic transformation. A significant linear regression was obtained, r(2) = 0.74, P <.001. The prediction equation obtained was natural logarithm (newborn nucleated RBC count) is equal to 1.002 x natural logarithm (placental nucleated RBC count) + 1.173. CONCLUSION: It is feasible to calculate nucleated RBC counts from histologic slides of the placenta that are predictive of newborn nucleated RBC counts. Further work on more homogeneous groups of subjects is necessary to increase the precision of the method. The placenta could serve as a surrogate source for newborn whole blood nucleated RBC counts around the time of birth.