Development of anthropomorphic hand phantoms for personal dosimetry in 90Y-Zevalin preparation and patient delivering.

Anthropomorphic tissue-equivalent hand phantoms were achieved to measure the extremity dose involved in Zevalin (90)Y-labelling and patient delivering procedure for radioimmunotherapy treatment of non-Hodgkin lymphoma. The extremity doses to hands and wrists of operators were measured by using thermoluminescent detectors mounted on the developed phantoms. Measurements of chest- and lens-equivalent doses performed on a Rando phantom are also reported.

Continuous infusion of vancomycin in methicillin-resistant staphylococcus infection.

OBJECTIVE: The aim of the study was to verify the therapeutic response of vancomycin in methicillin-resistant staphylococcus infection (MRSA/ MRCNS) administered according to two different methods (intermittent infusion vs. continuous infusion). METHOD: Experimental plan: retrospective study; study environment: university hospital, two intensive care units. Twenty-five critically ill patients submitted to antibiotic treatment with vancomycin for infection from MRSA/MRCNS were studied. The patients, who were classified according to SAPS II scores, were divided into two groups: group A (n = 14): dose of vancomycin of 0.5 g x 4/day and group B (n = 11): dose of 2 g/day of vancomycin administered in a continuous infusion. Before the antibiotic therapy was started (T1) and prior to its end (T2), the following parameters were evaluated: degree of impairment of the main organs and systems by means of sepsis-related organ failure assessment score (SOFA) and count of the white blood cells (WBC). The length of the hospital stay during intensive care was calculated for both groups (statistics: Student t test). RESULTS: No significant differences were found in the SAPS II scores and in the length of the hospital stay. In a comparison of the T1 and T2 results, we noted that patients of group A had no variations in the SOFA scores (4.84 +/- 2.48 vs. 4 +/- 3.9) and in the WBC mean values (12,415 +/- 5,099 vs. 12,841 +/- 6,864 cells/mm3). In contrast, in the patients of group B, we noted significant variations (p < 0.05) in the mean values of the SOFA scores (6.62 +/- 2.2 vs. 4.37 +/- 3.5) and in the mean values relative to the WBC count (17,242 +/- 12,842 vs. 10,757 +/- 3,610 cells/mm3). CONCLUSIONS: In critically ill patients suffering from MRSA/MRCNS infection, vancomycin administration in continuous infusions improved organ function and leukocyte response, but did not seem to modify the overall evolution of the disease.

Immediate-early genes expression in spinal cord as related to acute noxious stimulus.

During the "central sensitization" phenomenon, noxious stimuli lead to expression of IEGs (c-fos, c-jun, krox-24); their proteic products have been postulated to convert short-term stimulations into long-lasting responses in dorsal-horn neurons. The aim of this study was to verify if analgesic drugs, such as morphine and ketorolac, may affect the c-fos protooncogene expression by using a method highly sensitive and specific, based on transformation of activated c-fos specific mRNA in cDNA (reverse transcription), its amplification (PCR) and final visualization by electrophoresis on agarose gel. Male Wistar rats were submitted to various stimuli in order to assess which procedure resulted in genic derepression; monolateral sciatic nerve ligature appeared to be the most effective. When the animals were pretreated with morphine or ketorolac and subsequently exposed to the monolateral sciatic nerve ligature, or treated with ketorolac immediately after the same painful stimulus, we found that only pretreatment with morphine completely blocked c-fos depression. Our results confirm that pretreatment with opioids is able to prevent IEGs derepression and the central sensitization phenomenon.

[Expired ethane as a non-invasive marker of the course of experimental multiple organ dysfunction syndrome (MODS)]. / L'etano espirato come marker non invasivo della evoluzione della multiple organ dysfunction syndrome (MODS) sperimentale.

UNLABELLED: BACKGROUND AND WORK HYPOTHESIS: The mechanisms of organ damage in MODS are unclear. Given that lipid peroxidation induced by oxygen radicals may play a key role in organ damage, expired ethane, a marker of lipid peroxidation, could be correlated to the entity and evolution of experimental MODS. STUDY DESIGN AND METHODS: Forty wistar male rats (250 +/- 15 g body weight) were intraperitoneally injected with 10 ml of Zymosan mineral oil suspension (2.5%) to provoke MODS. Survival and symptoms were noted daily. On the 2nd, 7th and 14th day the animals underwent thorax CT scanning. CT images were processed to evaluate the relative density of lung parenchima. Expired ethane was measured using mass spectrometer and percentual changes were noted. Relative organ weight (liver and lung) were measured in 2nd, 7th and 14th day. STATISTICAL ANALYSIS: Pearson's linear correlation. RESULTS: The results show that maximal lung damage took place at the same moments as ethane concentrations peaked. A strict correlation (r = 0.93; p < 0.0001) was found between lung density and expired ethane. Strict correlation was found between organ weight, symptoms, survival and ethane production. CONCLUSIONS: Lipid peroxidation, as expressed by ethane production, might be an important cause of organ damage in MODS.

[Evaluation of an experimental model of multiple organ dysfunction]. / Valutazione di un modello sperimentale di disfunzione multipla di organo (MODS).

OBJECTIVE: To perform an experimental model of Multiple Organ Dysfunction Syndrome (MODS) without employing bacteria or endotoxin stimulus and to follow its evolution in vivo by a Computerized Tomography analysis of the lungs. DESIGN: Rats were submitted to intraperitoneal injection of a 2.5% zymosan suspension in mineral oil (1 g/kg weight) or mineral oil alone; control rats received no treatment. METHODS: The observation period was 15 days. During this period symptoms and survival were noticed daily. CT scans of lungs were made at the 7th and 14th days; data were post-processed to obtain information on lung density. The rats were sacrificed at the 15th day by heart puncture; blood was utilized for determination of hemochrome, differential leukocyte count, thrombocytes, glycemia, uremia, bilirubin. Lungs, liver, spleen and kidney were dissected and weighted for determination of relative organ weight. DATA ANALYSIS: Data were compared by "t" Student's test for impaired data and Fisher Exact test. RESULTS: Symptoms, survival, blood analysis and relative organ weight agreed with a progressive, ingravescent, triphasic illness caused by a systemic inflammatory response involving remote organ too. The CT study proved able to monitoring and analyzing organ damage: a temporal sequence of evolution of damage exists; organ damage is localized in microcirculatory system (density augment) and in parenchyma (morphologic alterations and fibrosis). DISCUSSION: The described experimental model reproduces a MODS-like illness in zymosan receiving rats; the CT scan is effective to evaluate the evolution of organ damage.

Oxygen-derived free radicals in the pathogenesis of experimental shock.

Oxygen-derived free radicals are naturally produced in biological systems mostly in ischemia and hypoxia related conditions. Imbalance of physiological defenses against oxygen-derived free radicals causes cellular damage. In our laboratory the role of oxygen radicals in the pathogenesis of circulatory shock was studied by exploiting the scavenging action of the spin-trapping compound phenyl-butyl-nitrone (PBN) in experiments concerning: (1) survival after shock, (2) microcirculatory derangements in endotoxin shock, (3) fluidity modifications of cell membranes during shock, (4) exhalation of ethane as non-invasive marker of shock. In some experiments the steroid methylprednisolone was used. Results showed that administration of PBN and of the steroid (1) ensures survival after otherwise lethal shock as confirmed by decreased ethane exhalation, (2) prevents microcirculatory troubles, (3) maintains stability of cell membranes. These findings strongly support the role of oxygen-derived free radicals in the pathogenesis and pathophysiology of circulatory shock.