Recent advances in research on radiofrequency fields and health: 2001-2003

The widespread use of wireless telecommunications devices, particularly mobile phones, has resulted in increased human exposure to radiofrequency (RF) fields. Although national and international agencies have established safety guidelines for exposure to RF fields, concerns remain about the potential for adverse health outcomes to occur in relation to RF field exposure. The extensive literature on RF fields and health has been reviewed by a number of authorities, including the Royal Society of Canada (1999), the European Commission's Scientific Committee on Toxicity, Ecotoxicity, and the Environment (CSTEE, 2001), the British Medical Association (2001), the Swedish Radiation Protection Authority (Boice & McLaughlin, 2002), and the Health Council of The Netherlands (2002). This report provides an update on recent research results on the potential health risks of RF fields since the publication of the Royal Society of Canada report in 1999 (See Krewski et al., 2001a) and our previous 2001 update (Krewski et al., 2001b), covering the period 2001-2003. The present report examines new data on dosimetry and exposure assessment, biological effects such as enzyme induction, and toxicological effects, including genotoxicity, carcinogenicity, and testicular and reproductive outcomes. Epidemiological studies of mobile phone users and occupationally exposed populations are examined, along with human and animal studies of neurological and behavioral effects. All of the authoritative reviews completed within the last 2 yr have concluded that there is no clear evidence of adverse health effects associated with RF fields. However, following a recent review of nine epidemiological studies of mobile phones and cancer, Kundi et al. (2004) concluded that the possibility of an enhanced cancer risk cannot be excluded. These same reviews support the need for further research to clarify the possible associations between RF fields and adverse health outcomes that have appeared in some reports. The results of the ongoing World Health Organization (WHO) study of mobile phones will provide important new information in this regard.     

Effects of hydrocodone rescheduling on opioid use outcomes: A systematic review

ObjectiveTo evaluate opioid prescribing, dispensing, and use in relation to hydrocodone-containing product (HCP) rescheduling.MethodsSeven biomedical databases and grey literature sources were searched with keywords and database-specific controlled vocabulary relevant to HCP rescheduling for items published between January 2014 and July 2019. We included English-language quasi-experimental studies that assessed changes in HCP and other opioid prescribing, dispensing, utilization, and opioid-related health outcomes before and after HCP rescheduling. A data extraction sheet was created for this review. Two authors evaluated risk of bias for each included study. Two of 4 authors each independently extracted patient demographics and opioid-related outcomes from the included studies. Conflicts were resolved by a third author.ResultsAll studies identified (n = 44) were quasi-experimental in design with 10 using an interrupted time series approach. A total of 24 studies reported a decrease in HCP prescribing by 3.1%-66.0%. Six studies reported a decrease in HCP days’ supply or doses by 14.0%-80.8%. There was increased prescribing of oxycodone-containing products by 4.5%-13.9% in 5 studies, tramadol by 2.7%-53.0% in 9 studies, codeine-containing products by 0.8%-1352.9% in 8 studies). Five studies reported a decrease in morphine equivalents by at least 10%, whereas 2 studies reported an increase in morphine equivalents. Differences in populations, sample sizes, and approaches did not allow for a meta-analysis. Details regarding approach and findings were limited in published conference abstracts (n = 16).ConclusionsHydrocodone rescheduling was associated with reductions in prescribing and use of HCPs but was also associated with increased prescribing and use of other opioids, both schedule II and nonschedule II.     

Short-term aerobic exercise training in obese humans with type 2 diabetes mellitus improves whole-body insulin sensitivity through gains in peripheral, not hepatic insulin sensitivity

CONTEXT: Short-term aerobic exercise training can improve whole-body insulin sensitivity in humans with type 2 diabetes mellitus; however, the contributions of peripheral and hepatic tissues to these improvements are not known. OBJECTIVE: Our objective was to determine the effect of 7-d aerobic exercise training on peripheral and hepatic insulin sensitivity during isoglycemic/hyperinsulinemic clamp conditions. DESIGN: Subjects were randomly assigned to one of two groups. The energy balance group consumed an isocaloric diet consisting of 50% carbohydrate, 30% fat, and 20% protein for 15 d. The energy balance plus exercise group consumed a similar diet over the 15 d and performed 50-min of treadmill walking at 70% of maximum oxygen consumption maximum during the second 7 d of the 15-d study period. Each subject underwent an initial isoglycemic/hyperinsulinemic clamp after 1-wk dietary control and a second clamp after completing the study. SETTING: The study was performed at Ohio State University's General Clinical Research Center. PARTICIPANTS: There were 18 obese, mildly diabetic humans included in the study. INTERVENTION: Aerobic exercise training was performed for 7 d. MAIN OUTCOME MEASURES: Whole-body, peripheral, and hepatic insulin sensitivity were measured. RESULTS: Exercise training did not have an impact on peripheral glucose uptake or endogenous glucose production during the basal state or low-dose insulin. Likewise, it did not alter endogenous glucose production during high-dose insulin. However, 1-wk of exercise training increased both whole-body (P<0.05) and peripheral insulin sensitivity (P<0.0001) during high-dose insulin. CONCLUSION: Improvements to whole body insulin sensitivity after short-term aerobic exercise training are due to gains in peripheral, not heptic insulin sensitivity.     

Rupture of the pregnant uterus – a 20-year review

Objectives: To examine the incidence, causative factors, maternal and foetal outcomes and subsequent fertility in cases of uterine rupture in scarred and unscarred uteri.

Methods: A 20 years’ retrospective review was carried out where relevant data were collected from the medical records. Outcome measures included labour characteristics, operative procedures, maternal and perinatal outcome in addition to subsequent fertility.

Results: Forty-nine cases of complete uterine rupture were identified. Women in the unscarred group were older, had higher parity and heavier babies (p values < 0.05). Alternatively, the scarred group cases were associated with more silent rupture discovered at time of surgery, recession of the presenting part and more visceral involvement in particularly the urinary bladder. Admission to NICU and birth asphyxia were more frequent in the scarred group while stillbirth and early neonatal death were more common in the unscarred one. Twenty-four out of 49 cases had repair with no bilateral tubal ligation and out of these, 13 patients subsequently conceived and had 22 babies.

Conclusion: Physicians should be vigilant to the risk factors and clinical presentations of uterine rupture during pregnancy. Cautious attempts to repair the ruptured uterus should be tried for patients’ wellbeing and to help maintain fertility.     

Sonographic assessment of first stage of labor progress (ULTRASONIC PARTOGRAM)

Purpose

To assess the role of ultrasound in the follow up of the progress of labor in terms of uterine wall thickness in its upper and lower segments.

Methods

This is a prospective cross sectional study conducted in the period from March 2012 to August 2012. Included a total of 43 low risk pregnant women at Dallah hospital, Riyadh, Kingdom of Saudi Arabia. Trans-abdominal ultrasound was used to measure the uterine wall thickness.

Results

With the progress of labor, the upper uterine wall progressively thickened, while the lower uterine segment progressively thinned. A significant change in uterine wall thickness was found with every 2 cm cervical dilatation. A sono-partogram was developed. There was no significant difference in uterine wall thickness with respect to gravidity. The upper/lower uterine wall thickness ratio may also be valuable in the assessment of the progress of labor. We found that, measuring the uterine wall thickness by trans abdominal US is a non invasive method which has the potential role for assessing the progress of labor especially in high risk pregnancies when digital examination carries the risk of ascending infection or bleeding as in patients with preterm labor, premature rupture of membranes or ante-partum hemorrhage.

Conclusions

Trans-abdominal US is a new non invasive method and has the potential for assessing the progress of labor. A sono-partogram is very useful in the follow up and evaluation of the progress of labor.     

Late Pseudocoarctation Syndrome After Stent-Graft Implantation For Traumatic Aortic Rupture

The present observation illustrates an unusual complication occurring after stent-grafting (S-graft) for aortic isthmus rupture. A 22-year-old patient, treated by S-graft in the emergency department for traumatic aortic rupture, was readmitted 10 months later with pseudocoarctation syndrome. A membrane was found inside the stent-graft that had induced a pseudo-dissection, which caused the pseudocoarctation syndrome. Surgical treatment consisted of removing the stent-graft and membrane and replacing it with a vascular implant. The patient’s clinical course was fair. The suggested mechanism was circumferential neoendothelialization of the stent-graft. Dehiscence caused the superior part of the membrane to drop into the lumen of the stent-graft creating a “false channel” that compressed the “true lumen” and induced “pseudocoarctation” syndrome. The cause of the extensive neointimalization remains unexplained. Thoracic aortic stent-grafts require regular follow-up monitoring by angioscan or angio-magnetic resonance imaging.     

Changes in platelet beta-thromboglobulin, fibrinogen, albumin, 5-hydroxytryptamine, ATP, and ADP during and after surgery with extracorporeal circulation in man

Surgery with extracorporeal circulation (ECC) is associated with transient alterations of platelet function whose pathogenic mechanisms are not completely understood. To define further the platelet abnormalities, we determined the changes in platelet content of several granule-associated substances during and after ECC in patients subjected to aortocoronary bypass surgery. Platelet beta-thromboglobulin (beta-TG) decreased to 79.8% of the preoperative level at the end of ECC (p less than 0.01) and, as expected, did not recover 1 hr after the end of surgery. Platelet fibrinogen and albumin decreased to 67.9% (p less than 0.01) and to 29.8% (p less than 0.01) of baseline, respectively. However, 1 hr after surgery, platelet fibrinogen rose to 92% and albumin to 55.5% of baseline, denoting that during the recovery from ECC, platelets incorporate some plasma proteins. During ECC, platelet 5-hydroxytryptamine (5-HT) and total ATP and ADP decreased to 50.8% (p less than 0.01), 63.2% (p less than 0.01), and 69.9% (p less than 0.01) of their respective preoperative values, indicating dense body release. One hour after surgery, ATP recovered to 83.8%, suggesting that previous depletion compromised also the metabolic pool of adenine nucleotides. In summary, Our results confirm and extend previous observations demonstrating alpha-granule release during ECC. Platelets undergoing ECC can incorporate plasma proteins as evidenced by the rapid increase of platelet fibrinogen and albumin after bypass. Although the mechanisms of this increase and site of storage of the exogenous substances are unknown, this observation justifies further studies to determine if internalization of plasma proteins, especially fibrinogen, may take place in physiological conditions. Dense body depletion with transient storage pool deficiency appears to be a component of the reduced platelet function during ECC. Consumption of metabolic ATP with alteration of platelet energy metabolism may further impair platelet function, contributing to the bleeding episodes observed during surgery with ECC.     

Should anti-Rh immunoglobulin be given to D variant women?

D variant women occasionally form anti-D during or following pregnancy with a D-positive fetus. It is not known whether Rh immunization could be suppressed by using anti-Rh immunoglobulin (Rh Ig), or whether the injected antibodies would be absorbed by the woman's D variant cells. In order to predict the likely outcome, three anti-Rh Ig preparations were absorbed independently with five examples of D variant red cells: R1VIr (n = 3), R1Br (n = 2), and with cells of common Rh-positive and Rh-negative phenotypes: R0, r'r, r"r or rr cells (n = 1 each). The titres of the Ig preparations against all these cells were compared after three, six, nine and 12 absorptions. The titres of the unabsorbed anti-Rh Igs against R0 cells ranged from 2(15) to 2(18). Anti-D activities were hardly affected by absorption with r'r, r"r or rr cells, but were completely exhausted after three to six absorptions with R0 cells. Most of the D variant cells were as ineffective as rr cells in reducing anti-D activity against R0 cells, but one R1VIr variant produced a fall in titre against R0 cells, equivalent to four or five doubling dilutions after three to six absorptions, which could not be reduced further by subsequent absorptions. Therefore, a substantial proportion of the anti-D in the immunoglobulin preparation does not bind to D variant red cells. The component of the anti-D that does not bind to D variant cells would be expected to be present in the circulation of D variant individuals injected with anti-Rh immunoglobulin, and should be effective in suppressing Rh immunization. An increased dose of the anti-Rh Ig might have to be administered in order to allow for the fraction that can bind to D variant red cells and which would not be available for immunosuppression.     

Presentation of acute central retinal vein occlusion in scleroderma

Central retinal vein occlusion (CRVO) is a rare complication of scleroderma. Here we report a case of a 30-year-old man who was diagnosed to have scleroderma in the rheumatology and dermatology clinic. During treatment with systemic steroids and immunosuppressive therapy the patient developed a sudden decrease of vision in the right eye and was diagnosed to have right CRVO with macular edema on fundus examination. After three consecutive Intravitreal bevacizumab (IVB) injections for macular edema, best-corrected visual acuity (BCVA) improved from 20/80 to 20/25. All ocular and systemic causes of CRVO other than scleroderma were excluded in our patient by thorough clinical examination and investigations, suggesting that scleroderma was the most possible etiology in his condition.     

Dupuytren's disease involving the wrist

There is a well-established association with ectopic fibrosis in Dupuytren's disease, but involvement of the wrist is rare. To our knowledge there have been only 5 cases reported in the literature. The authors present a patient with Dupuytren's disease involving only the proximal palm and wrist who presented with functional limitation and a rapid clinical progression.