Alterations in gastric mucus secretion in rhesus monkeys after exposure to ionizing radiation

The aim of the present study was to evaluate the effect of gamma-irradiation on soluble gastric mucus. Six conscious chair-adapted rhesus monkeys were studied once before and twice after exposure to ionizing irradiation (800 rads). Using a marker (99mTc-DTPA) dilution technique, acidic glycoprotein (AG), neutral glycoprotein (NG), ion, and fluid output were determined during a basal period and after the administration of an 80-ml water load. Irradiation significantly increased the outputs of both AG and NG during the basal period. After the water load, NG output remained elevated but irradiation abolished postload AG output thus inhibiting the normal rise in AG output stimulated by the load. Two days after irradiation NG output had returned to control levels whereas AG output was still suppressed. Sodium and potassium ion outputs were unaltered by irradiation. Chloride and fluid outputs were significantly inhibited on the day of irradiation but had returned to control levels within 3 days. These results indicate that irradiation produces significant changes in both the quantity and nature of the soluble mucus glycoproteins secreted into the gastric juice. It is suggested that these changes may compromise the protective ability of gastric mucus.     

Sudden cardiac death due to physical exercise in male competitive athletes. A report of six cases

In the period of 30 years, i.e. from 1973 to 2002, we noticed in Croatia 6 sudden and unexpected cardiac deaths in male athletes during or after training. Two were soccer players, 2 athletic runners, one was a rugby player and one was a basketball player. All of them were without cardiovascular symptoms. At the forensic autopsy, the first athlete, aged 29, had chronic myocarditis and thickened left ventricular wall of 15 mm. The second, aged 21, had an acute myocardial infarction of the posterior wall with normal coronaries and thickened left ventricular wall of 15 mm. The third aged 17, had hypoplastic right coronary artery and narrowed ascending aorta, suppurant tonsillitis and subacute myocarditis. Two athletes, aged 29 and 15, had hypertrophic cardiomyopathy and normal coronaries, and one dilated aorta. The sixth, aged 24, had arrhythmogenic cardiomyopathy of the right ventricle. All the 6 athletes died suddenly, obviously because of malignant ventricular arrhythmias. In Croatia the death rate among athletes reached 0.15/100 000, in others who practice exercise reached 0.74/100,000 and the difference is highly significant (c2=14.487, Poisson rates=3.81, P=0.00014) and in physicians-specialists reached 33.6/100,000. Preventive medical examinations are essential, especially in athletes before physical exercise, as are other investigations in every case suspicious of heart disease, including electrocardiogram (ECG), stress ECG, echocardiography and stress-echocardiography and other findings if indicated. Physical exercise is contraindicated in acute respiratory infection: in 2 of those cases had been a cause of death as a trigger.     

Estimate of the time zero lung burden of depleted uranium in Persian Gulf War veterans by the 24-hour urinary excretion and exponential decay analysis

The aim of this study was to estimate the amount of depleted uranium (DU) in the respiratory system of Allied Forces Gulf War Veterans. Mass spectrometry (thermal ionization mass spectrometry) analysis of 24-hour urinary excretion of DU isotopes in five positive (238U/235U > 191.00) and six negative (238U/235U > 138.25) veterans was utilized in the mathematical estimation of the pulmonary burden at the time of exposure. A minimum value for the biological half-life of ceramic DU oxide in the lungs was derived from the Battelle report of the minimum dissolution half-time in simulated interstitial lung fluid corresponding to 3.85 years. The average DU concentration was 3.27 x 10(-5) mg per 24 hours in DU-positive veterans and 1.46 x 10(-8) mg in DU-negative veterans. The estimated lung burden was 0.34 mg in the DU-positive and 0.00015 mg in the DU-negative veterans. Our results provide evidence that the pulmonary concentration of DU at time zero can be quantitated as late as 9 years after inhalational exposure.     

Echocardiographic analysis of changes in the heart in patients with systemic lupus erythematosus

Fifty-six patients, 49 females and 7 males, with the confirmed diagnosis of systemic lupus erythematosus were examined by M-mode, 2--D and Doppler echocardiography. Pericardial effusion was found in 15 patients (27%), while pericardial thickening was suspected in 6 additional patients (37.5% altogether). Two patients had the signs of a pericardial tamponade, but both of them were uraemic. Libman-Sacks endocarditis was suspected in 4 patients (7.5%) because of verrucous changes in the aortic or mitral valve and regurgitant jet. Slight to moderate left ventricular hypocontractility was present in 3 patients (5%), while 3 additional patients had borderline values of the left ventricular contractility parameters. Left ventricular hypertrophy, usually mild, was found in 21 patients (37.5%). Echocardiographic signs of pulmonary hypertension were present in 2 patients (3.6%). It has been concluded that pericardial affection is frequent during the course of systemic lupus erystematosus, while a diffuse myocardial involvement is rare, except the consequences of arterial hypertension and accelerated coronary atherosclerosis. Libman-Sacks endocarditis still represents a diagnostic problem. For a more precise definition of cardiac involvement in systemic lupus erythematosus, a comparative analysis of the disease activity and immunosuppressive therapy is needed.     

Effects of a metastatic (13762) and nonmetastatic (R3230AC) mammary adenocarcinoma on radiocolloid localization in regional lymph nodes in Fischer 344 rats

Effects of a metastatic and nonmetastatic tumor on radiocolloid localization in regional lymph nodes in the rat were studied in order to examine further the hypothesis that suppression of radiocolloid uptake results from inhibition of macrophage phagocytic function by tumor products. On the basis of data obtained in the present model using homogenates of autologous spleen and two weakly immunogenic tumors introduced into the foot pad of rats, it is proposed that decreased radiocolloid uptake induced by a regional neoplasm may result from proliferation of nonphagocytic cellular elements within the regional lymph nodes and alterations in the cell population at the site of radiocolloid injection, which impede the transport of interstitially administered radiocolloid and its access to phagocytic macrophages, within primary and secondary regional lymph nodes. In its inception, therefore, suppression of radiocolloid uptake is not unique to neoplasia and may not directly reflect altered phagocytosis.