Health Effects of Ionizing Radiation on the Human Body

Radioactivity is a process in which the nuclei of unstable atoms spontaneously decay, producing other nuclei and releasing energy in the form of ionizing radiation in the form of alpha (α) and beta (β) particles as well as the emission of gamma (γ) electromagnetic waves. People may be exposed to radiation in various forms, as casualties of nuclear accidents, workers in power plants, or while working and using different radiation sources in medicine and health care. Acute radiation syndrome (ARS) occurs in subjects exposed to a very high dose of radiation in a very short period of time. Each form of radiation has a unique pathophysiological effect. Unfortunately, higher organisms-human beings-in the course of evolution have not acquired receptors for the direct "capture" of radiation energy, which is transferred at the level of DNA, cells, tissues, and organs. Radiation in biological systems depends on the amount of absorbed energy and its spatial distribution, particularly depending on the linear energy transfer (LET). Photon radiation with low LET leads to homogeneous energy deposition in the entire tissue volume. On the other hand, radiation with a high LET produces a fast Bragg peak, which generates a low input dose, whereby the penetration depth into the tissue increases with the radiation energy. The consequences are mutations, apoptosis, the development of cancer, and cell death. The most sensitive cells are those that divide intensively-bone marrow cells, digestive tract cells, reproductive cells, and skin cells. The health care system and the public should raise awareness of the consequences of ionizing radiation. Therefore, our aim is to identify the consequences of ARS taking into account radiation damage to the respiratory system, nervous system, hematopoietic system, gastrointestinal tract, and skin.

Cardiopulmonary Interactions with Consecutive Pulmonary Abnormalities in Patients with Chronic Heart Failure

Chronic heart failure places heavy burden on patients, their families and on health care resources, accounting for high numbers of hospital admissions. Despite huge improvements in the treatment of many heart disorders, the clinical syndrome of chronic heart failure as a final pathway of heart pathology is an exception, in that its prevalence is rising, and only small prolongations in survival are occurring. It is associated with high morbidity and poor prognosis, and a survival rate worse than that for some malignant tumors. The reasons for the increasing overall prevalence of chronic heart failure in developed countries lie in prolonged survival owing to modern pharmacological or invasive treatment, better secondary prevention, and aging of the population. Chronic pulmonary disease is common in patients with chronic heart failure. Through sharing some risk factors and overlapping pathophysiological processes, they present diagnostic and therapeutic challenge. The aim of this article is to review various mechanisms responsible for the symptoms of chronic heart failure with consecutive pulmonary interaction and abnormalities in lung function.

Brain tumor as a prototype of severe brain lesion in patients with "low T3 syndrome"

The purpose of our study was to contribute to better understanding of cerebrospinal fluid (CSF) as a valuable biological material in the research of brain tumors within the "low T3 syndrome", and to discuss the role of thyroid hormones in the central nervous system in subjects with severe cerebral lesions. We studied the levels of total triiodothyronine (tT3), total thyroxine (tT4), free triiodothyronine (fT3), free thyroxine (fT4), reverse triiodothyronine (rT3) and thyrotropin (TSH) in serum, and fT3, fT4, rT3 and TSH levels in CSF of patients with brain tumor, and compared the results with control group. Study results indicated a statistically significantly higher level of rT3 in serum and CSF of brain tumor patients vs. control group (p < 0.05). The rT3/fT3 ratio was highest in CSF and serum of brain tumor patients, yielding a statistically significant difference (p < 0.05). These results could suggest higher permeability of the blood-brain barrier in brain tumor patients. We also assume that rT3, in the framework of"cerebral low T3 syndrome", is also generated through local intracerebral conversion. Disruption of this process in severe cerebral lesion can lead to increased rT3 concentrations, i.e. development of the "low T3 syndrome".

[The role of KRAS gene mutation testing in colorectal cancer--a predictive biomarker of response to EGFR inhibitors therapy]

Activation of KRAS oncogene has been implicated in colorectal carcinogenesis. KRAS mutations can be detected in more than 30% of all patients with colorectal cancer (CRC). Most recently, regimens that include anti-epidermal growth factor receptor (EGFR) targeted antibodies, cetuximab and panitumumab, for metastatic CRC have been developed. Several recent studies have shown that patients with KRAS mutations in codons 12 and 13 in metastatic CRC do not benefit from anti-EGFR therapy. With the aim to determine KRAS status as predictive biomarker, 7 known mutations ofKRAS gene in codons 12 or 13 on 44 CRC samples were tested. After DNA extraction from paraffin-embedded tumor tissue blocks, KRAS mutations were analysed using quantitative real-time PCR with internationally certified method, for the first time in Croatia. Mutations were detected in 12 tumor samples: five patients with Gly12Val (GGT>GTT), three with Gly12Asp (GGT>GAT), two patients with Gly13Asp (GGC>GAC), one patient with Gly12Ser (GGT>AGT) and one with Gly12Cys (GGT>TGT) mutation in tumor. Our data about KRAS mutational status in the sample of Croatian population diagnosed with CRC have shown that incidence of KRAS mutation is 27%, which is consistent with results already reported worldwide. The final result must be a proper selection of the correct therapy with EGFR inhibitors for the patients with CRC which is critical for improving clinical outcomes, unnecessary toxicities, side effects and financial cost.

Intravascular lymphoma and thyroid gland

Intravascular lymphoma (IVL) is a rare disease characterized by the proliferation of neoplastic cells in the small blood vessels that frequently goes undiagnosed until the time of autopsy. The neoplastic cells are usually of B-cell origin. The clinical course was examined to determine factors that would facilitate antemortem diagnosis. IVL is observed with clinical, histopathological and immunohystochemical methods. This is a unique case because the thyroid gland is a rare place for IVL. Accent is given on immunohystochemical methods and tissue biopsy in the differential diagnosis of IVL when nervous system and thyroid gland dysfunction occur This report indicates that micro-ecosystem of multinodular goitrous might influence the expression of chemokines and/or adhesion moleculs on endothelial and lymphoma cells, leading to heavy infiltration of thyroid gland. Concurrently, that may guide the physician to tissue biopsy facilitating antemortem diagnosis and institution of appropriate therapy.

Fatalities in the war in Croatia, 1991 and 1992. Underlying and external causes of death

OBJECTIVE

To show the underlying and external causes of death and selected characteristics of those killed in the war in Croatia between March 1991 and December 1992.

DESIGN

Analysis of 4339 fatalities recorded on two national mortality statistics documents that specified war operations as the cause of death: a demography mortality statistical form and a death certificate.

MAIN OUTCOME MEASURES

The frequency of clinical causes of death and their association with methods of wounding, length of survival, and attendant diagnoses.

RESULTS

Half of those killed were men aged 21 to 35 years. Among women killed, the majority were aged 61 to 75 years. Skull fracture with intracranial injuries was the leading cause of death (28.9%), followed by multiple traumas and injuries of unspecified site (17.9%), and thoracic wounds with lung and heart injuries (17.6%). The most common methods of wounding were bombs and fragments of other explosive devices involving 1907 persons (43.9%), followed by deaths from bullet wounds (33.0%). More than 50% of those killed had sustained multiple injuries. In 78.6% of the cases, death immediately followed the wounding.