Exposure to electromagnetic fields and the risk of leukemia

Evidence from animal experiments and human studies suggests that electromagnetic fields may be human leukemogens. Epidemiological studies of leukemia in occupational groups and in the general populations are reviewed. The results are inconsistent. In the few studies showing an association between exposure to electromagnetic fields and the risk of leukemia, the temporal relationship between exposure and effect was not established, the observed associations were weak, the dose-response relationships were based on qualitative levels of exposure without regard to the duration of exposure or secondary sources of exposure, and the risk ratios were probably biased due to the population selection procedures used and misclassification of exposure. The proportionate mortality or cancer incidence ratios are unreliable estimates of relative risk. Further epidemiological research is needed to establish an association between exposure to electromagnetic fields and the risk of leukemia.     

Does pre-treatment with micronized progesterone affect the ovarian response to a gonadotropin releasing hormone agonist flare-up protocol?

The purpose of this study was to investigate the ovarian response and the receptivity of the endometrium in women pre-treated with micronized progesterone. Eighty-two normogonodotropic women undergoing in vitro fertilization were studied. Thirty received micronized progesterone 1500 mg/day from day 21 of the cycle for a minimum of 2 weeks, and 52 did not receive micronized progesterone (control group). A gonadotropin releasing hormone agonist (GnRH-a) was administered to all the patients in the follicular phase (flare-up). Twenty-five cycles were cancelled for fertilization failure due to male factor, 12 (40%) in the progesterone group and 13 (25%) in the control group (p = 0.271). There was no difference in the number of oocytes retrieved (7.3 +/- 5 vs. 8.2 +/- 4), fertilization rate (50.8% vs. 65%), clinical pregnancy rate (16.6% vs. 25%) or implantation rate (8% vs. 14%). In the progesterone group cases without fertilization, we performed two biopsies to evaluate the receptivity of the endometrium. Pinopode expression was noted 7 days after oocyte retrieval. It seems that the administration of micronized progesterone in the previous cycle does not affect the ovarian response to the combination of follicular phase GnRH-a and gonadotropins, nor the receptivity of the endometrium.     

What is the place of electroneuromyographic studies in the diagnosis and management of pudendal neuralgia related to entrapment syndrome?

Entrapment of the pudendal nerve may be at the origin of chronic perineal pain. This syndrome must be diagnosed because this can result in the indication of surgical decompression of the entrapped nerve for pain relief. Electroneuromyographic (ENMG) investigation is often performed in this context, based on needle electromyography and the study of sacral reflex and pudendal nerve motor latencies. The limits of ENMG investigation, owing to various pathophysiological and technical considerations, should be known. The employed techniques do not assess directly the pathophysiological mechanisms of pain but rather correlate to structural alterations of the pudendal nerve (demyelination or axonal loss). In addition, only direct or reflex motor innervation is investigated, whereas sensory nerve conduction studies should be more sensitive to detect nerve compression. Finally, ENMG cannot differentiate entrapment from other causes of pudendal nerve lesion (stretch induced by surgical procedures, obstetrical damage, chronic constipation...). Thus, perineal ENMG has a limited sensitivity and specificity in the diagnosis of pudendal nerve entrapment syndrome and does not give direct information about pain mechanisms. Pudendal neuralgia related to nerve entrapment is mainly suspected on specific clinical features and perineal ENMG examination provides additional, but no definitive clues, for the diagnosis or the localization of the site of compression. In fact, the main value of ENMG is to assess objectively pudendal motor innervation when a surgical decompression is considered. Perineal ENMG might predict the outcome of surgery but is of no value for intraoperative monitoring.     

Lack of predictability of cefotetan in vitro susceptibility tests against cefotetan-resistant anaerobic bacteria in determining clinical and bacteriologic efficacies.

Interpretive criteria for cefotetan in vitro susceptibility testing appear to be clinically relevant when applied to aerobic bacteria. To determine whether the same was true for anaerobic bacteria, we conducted a retrospective analysis of intraabdominal, gynecologic, and skin and skin structure infections treated with cefotetan. Of the infections, 202 contained at least one anaerobe isolate. Of the 51 patients, 47 (92.9%) from whom one or more cefotetan-resistant anaerobes were isolated were clinically cured or showed improvement. Similarly, cefotetan was efficacious for 95.4% of the patients harboring only cefotetan-susceptible anaerobes. Favorable bacteriologic responses were observed in 94.1% and 97.4% of these patient groups, respectively. The data suggests that the therapeutic utility of cefotetan against anaerobic bacteria cannot be accurately predicted on the basis of in vitro susceptibility test results alone but may be explained by a variety of factors, as discussed in this report.     

p63 expression in assessment of bronchioloalveolar proliferations of the lung.

Discrimination of well-differentiated pulmonary adenocarcinoma from reactive bronchioloalveolar epithelium can be difficult on routine histology, especially with small biopsies. Ancillary studies to help in this distinction are desirable. p63, a p53-homologous nuclear protein, is a marker of reserve cells of the bronchus and terminal lobular unit. In this study, 33 cases of adenocarcinoma (20 open lung and 13 transbronchial/percutaneous biopsies) and 43 cases of benign lungs with fibrosis and metaplasia (22 open lung and 21 transbronchial/percutaneous biopsies) were studied for nuclear p63 expression by immunohistochemistry (Dako, Carpinteria, CA, USA). Five additional cases each of atypical adenomatous hyperplasia and adenosquamous carcinoma and three cases of squamous carcinoma (all open lung biopsies) were also stained. The diagnostic categories of benign lung conditions were usual interstitial pneumonia, parenchymal scar, cryptogenic organizing pneumonia and diffuse alveolar damage. In neoplastic cases, p63 positivity was calculated as percentage of all tumor cells examined. In areas of normal lung, p63 decorated the reserve cells of large and small airways and occasional cells of the distal lobular unit. In fibrotic reactive processes, an interrupted but distinct pattern of nuclear staining was present in all cases, with staining of basal cells of the airways as well as bronchiolar- and squamous-metaplastic epithelium (43/43, 100%). p63 immunoreactivity was less uniform in areas of acute lung injury within these cases. One adenocarcinoma and two cases of atypical adenomatous hyperplasia showed strong immunoreactivity (>80%), while three adenocarcinomas highlighted only rare tumor nuclei (<5% of tumor cells). Morphologic areas where p63 immunostaining was not helpful included the junction of normal lung and lepidic growth of adenocarcinoma, and retrograde spread of adenocarcinoma into small airways. Our results highlight the differential expression of p63 across various bronchioloalveolar lesions. Moreover, p63 may be helpful in distinguishing reactive from neoplastic glandular proliferations in the lung.     

Diagnosis and management (by subxiphoid pericardiotomy) of large pericardial effusions causing cardiac tamponade.

To determine the clinical features, course and outcome of patients with cardiac tamponade, 57 consecutive patients with new, large pericardial effusions were prospectively studied. Twenty-five patients (44%) developed cardiac tamponade with venous hypertension and a pulsus paradoxus greater than 10 mm Hg. Electrocardiography, radiographic studies and echocardiography did not differentiate patients with and without tamponade. All 57 patients underwent thorough diagnostic evaluation followed by subxiphoid pericardial biopsy and drainage. A diagnosis was obtained in 53 patients (93%). Collagen vascular disease was significantly more frequent in the 25 patients with than in the 32 without cardiac tamponade (24 vs 3%; p less than 0.05). The frequency of malignant and uremic effusions was equal in both groups, whereas radiation-induced effusions seldom produced tamponade. At 1-year follow-up, 3 patients (12%) with tamponade had recurrent effusions, and 1 needed reoperation. This was not significantly different from the 32 patients without tamponade. Twelve-month mortality was also similar in both groups (36 vs 44%). This prospective series disclosed several unexpected findings: (1) Cardiac tamponade occurred in almost 50% of patients with new large pericardial effusions; (2) both malignancy and collagen vascular disease occurred with equal frequency as etiologies, whereas radiation-induced tamponade was unusual; (3) thorough clinical evaluation resulted in few idiopathic etiologies; and (4) subxiphoid pericardiotomy was effective for both diagnosis and therapy of tamponade.     

Hyperoxia improves microvascular perfusion in a murine wound model

There is a need for a noninvasive method that measures wound angiogenesis. Hyperoxia is known to increase the appearance of new blood vessels in wounds, yet no study has confirmed increases in wound bed perfusion with periodic hyperbaric oxygen (HBO) exposure. This study investigates whether laser Doppler imaging is able to detect and quantify the enhancement of wound angiogenesis that is known to occur with intermittent HBO treatments. Full-thickness dorsal dermal wounds were created on mice randomized to hyperoxic (n = 14) and control (n = 15) groups. Hyperbaric oxygen was administered twice daily for 90 minutes each at 2.1 atmospheres for 7 days. Wound bed perfusion was measured by laser Doppler imaging on days 0, 7, and 10 postwounding. Wound blood flow increased significantly over baseline on day 7 and 10 in the hyperoxic group, but only on day 10 in the control group. Comparison between groups showed a 20% statistically significant increase in wound perfusion in HBO-treated animals compared to control on day 10 (p = 0.05). Laser Doppler imaging was able to detect and quantify the increase in wound bed perfusion resulting from intermittent HBO treatments and shows promise as a noninvasive measure of angiogenesis and wound healing.