Electromagnetic Fields as a Health Risk Factor

This study is a collection of findings of published articles from the Department of Medical Biophysics and Department of Public Health at the Jessenius Faculty of Medicine in Martin, Comenius University Bratislava (JFM CU) with the topic on epidemiology of electromagnetic fields. During 14 years, 13 principal publications were created, of which 11 studies deal with radio frequency signals from mobile phones (mainly GSM900 and GSM1800 standard); one study describes the construction of a new exposure system and the other deals with the effects of low frequency electromagnetic fields. The results showed that the electromagnetic fields can affect heart rate variability both in humans and animals; increasing the activity of the parasympathetic or sympathetic nerve systems depending on place of body exposure (head or thorax, respectively); may cause disorders of heart rhythm; loss of concentration; headaches; and/or burning sensations in the ear area. Parameters of exposition were compared with the values issued by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). They had not exceeded the permitted limits. However, compared to data of the Bio Initiative Report, in some cases, our measured values exceeded their limits.

Metachronous isolated locally advanced pancreatic metastasis from chromophobe renal cell carcinoma

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Isolated pancreatic metastasis from renal cell carcinoma is relatively rare and it's usually seen in clear cell renal cell carcinoma (CCRCC), but its occurrence from chromophobe renal cell carcinoma is extremely rare.

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Pancreatic location is often diagnosed during routine surveillance imaging for the primary lesion.

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Patients in whom the pancreas is the only metastatic site and who are fit enough to undergo pancreatic surgery appear to be good candidates for the surgical treatment chemotherapy can improve the quality of life but not survival.

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It is necessary a long- term follow-up for patients treated for tumors with known low-grade metastatic potential and relatively good prognosis such as chromophobe renal cell carcinoma.

Introduction

Metastasis to the pancreas is relatively uncommon occurrence. Isolated pancreatic metastasis from renal cell carcinoma (RCC) is relatively rare and it’s usually seen in clear cell renal cell carcinoma (CCRCC), but its occurrence from chromophobe renal cell carcinoma (chRCC) is extremely rare, due to its relatively low-grade metastatic potential.

Presentation of case

The authors report an unusual case of metachronous isolated pancreatic metastasis, in a 65-year-old female patient two years after left nephrectomy for chRCC, diagnosed during routine surveillance imaging and confirmed after a CT-guided pancreatic biopsy.

Discussion

The pancreas is an elective site for metastases from RCC, and this particularity has been reported by several studies, but only described for CCRCC. In the English literature there is only one case of pancreatic metastasis from chRCC diagnosed in an autopsy study. Surgical resection of metastasis remains the most effective treatment, particularly for pancreatic metastases from chRCC, since radiotherapy, chemotherapy, hormonal therapy, and targeted therapy have generally proved ineffective for metastatic chRCC. In case of an unresectable disease, surgical or endoscopic palliation in association with palliative chemotherapy can improve the quality of life but not survival.

Conclusion

This case highlights the unique behavior of chRCC with an unusual site of metastasis, and the necessity of long-term follow-up after primary tumor removal, even if it is known for a low-grade metastatic potential and a relatively good prognosis.

Abnormal vocal cord movement in patients with and without airway obstruction and asthma symptoms

BACKGROUND

Abnormal vocal cord movements can cause laryngeal extrathoracic airway obstruction (often called vocal cord dysfunction - VCD) leading to asthma-like symptoms. These aberrant movements are characteristically present during inspiration and termed paradoxical vocal cord movement (PVCM). We have reported PVCM in up to 40% of severe asthmatics, but it is not known if PVCM is detectable in all patients with asthma-like symptoms and if the condition is more often associated with abnormal lung function.

OBJECTIVE

We hypothesized that PVCM is frequently associated with asthma symptoms accompanied by airflow limitation. Studies examined whether PVCM is solely linked to experiencing asthma symptoms, or if PVCM is related to airflow limitation and/or other disease characteristics.

METHODS

Patients with asthma symptoms were recruited from general practice and severe asthma clinics (n = 155). Pulmonary function measurements were conducted, asthma control and Nijmegen (dysfunctional breathing) questionnaires were administered and skin prick testing was carried out. PVCM was quantified using dynamic 320-slice computerized tomography of the larynx. Groups were divided into patients with FEV₁ ≥ 80% predicted or FEV₁ < 80% predicted and FEV₁ /FVC < 0.7. ATS/ERS definitions of severity were also applied and evaluated. Detection of PVCM in the groups was compared and analyses performed to identify features associated with PVCM.

RESULTS

Overall (n = 155), PVCM was detected in 42 cases (27.1%). Patients with FEV₁ < 80% predicted had PVCM more often (25/68, 36.8%) than individuals with normal spirometry (17/87, 19.5%; P = 0.016). PVCM was associated with older age (P = 0.003) and with Nijmegen scores > 20 (P = 0.04). Patients with FEV₁ < 80% predicted plus Nijmegen scores > 20 were more likely to have PVCM (OR = 9.3, P = 0.02).

CONCLUSIONS AND CLINICAL RELEVANCE

Paradoxical vocal cord movement is more often associated with asthma symptoms accompanied by airflow limitation and dysfunctional breathing. Further studies are needed to determine whether PVCM is induced by dysfunctional breathing practices and/or airway obstruction. How PVCM links with symptomatic asthma and VCD also requires evaluation.

Conditions for integrability of Markov chains

We give simple sufficient conditions for integrability of continuous-time Markov chains in terms of their infinitesimal parameters. Similar conditions for regularity are stated first, and a simple proof given.

Escape from the boundary in Markov population processes

Density dependent Markov population processes in large populations of size N were shown by Kurtz (1970), (1971) to be well approximated over finite time intervals by the solution of the differential equations that describe their average drift, and to exhibit stochastic fluctuations about this deterministic solution on the scale √N that can be approximated by a diffusion process. Here, motivated by an example from evolutionary biology, we are concerned with describing how such a process leaves an absorbing boundary. Initially, one or more of the populations is of size much smaller than N, and the length of time taken until all populations have sizes comparable to N then becomes infinite as N → ∞. Under suitable assumptions, we show that in the early stages of development, up to the time when all populations have sizes at least N1-α for 1/3 < α < 1, the process can be accurately approximated in total variation by a Markov branching process. Thereafter, it is well approximated by the deterministic solution starting from the original initial point, but with a random time delay. Analogous behaviour is also established for a Markov process approaching an equilibrium on a boundary, where one or more of the populations become extinct.

The primordial follicle reserve is not renewed after chemical or γ-irradiation mediated depletion

Reports indicate that germ-line stem cells present in adult mice can rapidly generate new oocytes and contribute to the primordial follicle reserve following conditions of ovotoxic stress. We further investigated the hypothesis that adult mice have the capacity to generate new oocytes by monitoring primordial follicle numbers throughout postnatal life and following depletion of the primordial follicle reserve by exposure to doxorubicin (DXR), trichostatin A (TSA), or whole-body γ-irradiation. We show that primordial follicle number remains stable in adult C57BL/6 mice between the ages of 25 and 100 days. However, within 2 days of treatment with DXR or TSA, primordial follicle numbers had declined to 65 and 51% respectively (P<0.05-0.01 when compared to untreated controls), with no restoration of follicle numbers evident after 7 days for either treatment. Furthermore, ovaries from mice subjected to sterilizing doses of γ-irradiation (0.45 or 4.5 Gy) revealed complete ablation of all primordial follicles 5 days after treatment, with no indication of follicular renewal. We conclude that neo-folliculogenesis does not occur following chemical or γ-irradiation mediated depletion of the primordial follicle reserve.

[Uncommon etiology of cruralgia]

A 58 year old man suffered from low back pain. Physical examination showed asymmetry of the quadriceps and slight motor deficiency of right leg. Plain radiography of the pelvis revealed a large osteophyte, developed anteriorly at the low part of the right sacro iliac joint. CT exam of lumbar spin was normal. But, it confirmed osteophyte of right sacro iliac. Percutaneous injection of a small quantity of xylocaine under CT guidance in the site of the osteophyte behind crural muscle was marked by immediate disappearance of the pain, confirming the site of conflict between the crural nerve and the osteophyte. The patient was treated by injection of corticosteroid at the same location. Recovery was good.

[Tuberculous spondylitis with syndesmophytes and paraspinal ossification. Two case reports]

The authors described 2 patients with spinal tuberculosis. The first one was presented with multiple anterior marginal involvement of vertebral bodies, centrosomatic spondylitis of L3, associated with a syndesmophytic showing spinal ossification. In the second case, spinal tuberculosis involved the vertebral arc of L2 and L4. A paravertebral ossification on both sides of L4 was seen. The nature of these vertebral and paravertebral ossifications was discussed.

[Radiological diagnosis of calcifications of the portal vein. Apropos of a case]

The very rare portal vein calcifictions are detected in patients with a portal hypertension syndrome (PHT). A patient with hepatosplenomegaly and mild signs of PHT presented images of parietal calcifications, and the diagnostic values of different imaging techniques, particularly ultrasound and CT scan, are compared.