Sex-Linked Differences in Cardiac Atrophy After Mechanical Unloading Induced by Heterotopic Heart Transplantation.

No information is available about sex-related differences in unloading-induced cardiac atrophy. We aimed to compare the course of unloading-induced cardiac atrophy in intact (without gonadectomy) male and female rats, and in animals after gonadectomy, to obtain insight into the influence of sex hormones on this process. Heterotopic heart transplantation (HT((x)) was used as a model for heart unloading. Cardiac atrophy was assessed as the weight ratio of heterotopically transplanted heart weight (HW) to the native HW on days 7 and 14 after HTx in intact male and female rats. In separate experimental groups, gonadectomy was performed in male and female recipient animals 28 days before HT(x) and the course of cardiac atrophy was again evaluated on days 7 and 14 after HT(x). In intact male rats, HT(x) resulted in significantly greater decreases in whole HW when compared to intact female rats. The dynamics of the left ventricle (LV) and right ventricle (RV) atrophy after HT(x) was quite similar to that of whole hearts. Gonadectomy did not have any significant effect on the decreases in whole HW, LV, and RV weights, with similar results in male and female rats. Our results show that the development of unloading-induced cardiac atrophy is substantially reduced in female rats when compared to male rats. Since gonadectomy did not alter the course of cardiac atrophy after HTx, similarly in both male and female rats, we conclude that sex-linked differences in the development of unloading-induced cardiac atrophy are not caused by the activity of sex hormones.

Heterotopic Ossifications after Fractures of the Anterior Pelvic Segment: Overview of Morphology and Clinical Correlations.

PURPOSE OF THE STUDY In certain patients after treated pelvic fractures, heterotopic ossifications can be observed in the area of the pubic bone, which protrude ventrally, and often also laterally and distally into surrounding soft tissues of the groin or even medially into the proximal thigh. These ossifications are shaped like sharp spikes of various lengths, which is why the authors refer to them as "spicules". In some patients, these ossifications are also associated with pain. The aim of this study was to provide an overview of the morphology of heterotopic ossifications of the anterior segment of the pelvis and to discuss the etiology of their origin, and further to determine the incidence, risk factors and clinical significance of these "spike-like" ossifications. MATERIAL AND METHODS X-ray images of patients treated for pelvic injuries between 2009 and 2018, in whom radiological documentation was available at least 12 months after the injury or surgery were evaluated. Patients with acetabular fractures or combined pelvic and acetabular injuries were not included in the study. Possible risk factors studied included gender, severity of injury, type of fracture according to the AO / ASIF classification, concomitant bladder injury, method of treatment and type of osteosynthesis of the anterior segment of the pelvis. The categorial data concerning risk factors for the observed "spicule" type ossifications was statistically evaluated using the chi-square test at the 5% level of significance. RESULTS The studied group consisted of 218 patients (121 women, 97 men) aged 13 to 92 years of age (mean age was 54 years, median age was 55 years). Heterotopic "spicule" type ossifications occurred in 21 patients (4 females, 17 males) aged 18 to 76 years (mean 39 years, median 41 years). Significant risk factors in the observed ossification group included male sex (p = 0.0004), severity of trauma (predominance of "spicules" was seen in multiple trauma patients, (p = 0.0024), unstable pelvic injury according to AO / ASIF classification (predominance of "spicules" in type B and C fractures over type A fractures, (p = 0.0013), concomitant bladder injury (p = 0.0009) and in patients undergoing surgical treatment of the fracture (p < 0.0001), where all the observed spicules were seen in patients undergoing anterior pelvic segment osteosynthesis. A statistically significant difference was also evident when comparing the osteosynthetic material used in the anterior segment (a increased incidence of ossifications was seen in patients undergoing plate fixation compared to patients in whom pubic screws were used, p = 0.0050). DISCUSSION Heterotopic ossifications are described as relatively common consequences of pelvic fractures, but are not considered a major problem because they usually do not produce any clinical correlations. The causes of post-traumatic and postoperative ossifications in the pelvic area include the effects of high energy traumas, extensive surgical procedures, prolonged artificial lung ventilation, and post-infectious states after complications of surgical treatment. CONCLUSIONS The study identified risk factors for heterotopic "spicule" type ossifications. The identified risk factors include male sex, severity of injury, unstable type of fracture, concomitant bladder injury, surgical treatment, and the use of massive implants. Only the effect of bladder injuries can be partially influenced by performing less invasive surgical techniques during combined pelvic and bladder injuries. Key words: pelvic fracture, pelvic injury, complications, heterotopic ossifications, multiple trauma, unstable pelvic trauma, urinary bladder injury.

Region-specific sensitivity of the spinal cord to ischemia/reperfusion: the dynamic of changes in catalytic NOS activity.

This study was designed in order to consider whether the release of neuronally derived nitric oxide (NO) in the lumbosacral spinal cord during ischemia/reperfusion is region-specific and whether changes in Ca(2+)-dependent NO synthase (cNOS) activity paralell with functional outcome. The cNOS activity was measured in the spinal cord regions after 13-, 15- and 17-min ischemia alone and that followed by 24 h of reperfusion. In addition, the Tarlov's criteria were applied to define the neurological consequences of ischemia/reperfusion in experimental animals. Based on the results, it is evident that only the 17-min ischemia alone was quite sufficient to cause changes in cNOS activity, however, without alterations in functional outcomes. On the other hand, the ischemic episodes followed by reperfusion caused dynamic, region-specific alterations in cNOS activity and consequently led to deterioration of motor function of hindlimbs in affected animals. Our results indicate that the motoneurons in the ventral horns respond more sensitively to ischemia/reperfusion than do neurons localized in the other spinal cord regions and that changes in cNOS activity may also influence the axonal conductance in the white matter and account for the impairment of motoneuronal activity in affected animals.

Neuronal nitric oxide synthase immunopositivity in motoneurons of the rabbit's spinal cord after transient ischemia/reperfusion injury.

1. Motoneurons in the spinal cord are especially vulnerable to ischemic injury and selectively destroyed after transient ischemia. To evaluate the role of nitric oxide (NO) in the pathophysiology of the spinal cord ischemia, the expression of neuronal nitric oxide synthase (nNOS) in the motoneurons of the lumbosacral spinal cord was examined in the rabbit model of transient abdominal aorta occlusion. 2. The aim of the present study was to find if there is any consensus between the duration of transient abdominal aorta occlusion, nNOS positivity of the motoneurons and neurological hind limb impairment. 3. According to the degree of neurological damage (i.e., from the group with almost no sign of damage to a group with fully developed paraplegia), the experimental animals were divided into three groups. The respective spinal cord segments of each experimental group were compared to the control group. 4. Spinal cord ischemia (15 min) was induced by Fogarty arterial embolectomy catheter occlusion of abdominal aorta with a reperfusion period of 7 days. On seventh day, the sections of lumbosacral segments were immunohistochemically treated and L1-L7, and S1-S2 segment sections were monitored using light microscopy.

Spatiotemporal alterations of the NO/NOS neuronal pools following transient abdominal aorta occlusion: morphological and biochemical studies in the rabbit.

1. Brief interruption of spinal cord blood flow resulting from transient abdominal aortic occlusion may lead to degeneration of specific spinal cord neurons and to irreversible loss of neurological function. The alteration of nitric oxide/nitric oxide synthase (NO/NOS) pool occurring after ischemic insult may play a protective or destructive role in neuronal survival of affected spinal cord segments. 2. In the present study, the spatiotemporal changes of NOS following transient ischemia were evaluated by investigating neuronal NOS immunoreactivity (nNOS-IR), reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) histochemistry, and calcium-dependent NOS (cNOS) conversion of [(3)H] l-arginine to [(3)H] l-citrulline. 3. The greatest levels of these enzymes and activities were detected in the dorsal horn, which appeared to be most resistant to ischemia. In that area, the first significant increase in NADPHd staining and cNOS catalytic activity was found immediately after a 15-min ischemic insult. 4. Increases in the ventral horn were observed later (i.e., after a 24-h reperfusion period). While the most intense increase in nNOS-IR was detected in surviving motoneurons of animals with a shorter ischemic insult (13 min), the greatest increase of cNOS catalytic activity and NADPHd staining of the endothelial cells was found after stronger insult (15 min). 5. Given that the highest levels of nNOS, NADPHd, and cNOS were found in the ischemia-resistant dorsal horn, and nNOS-IR in surviving motoneurons, it is possible that NO production may play a neuroprotective role in ischemic/reperfusion injury.

Toxicological classification of pesticides.

The authors put forth their proposition for pesticide classification from the points of view of acute toxicity, skin irritation, skin toxicity 'resorption), cummulation coefficient and chronic effect--anticipated chronic risk. The proposition of this kind may be considered a priority in Czechoslovakia. It is confronted with the criteria for pesticide classification recommended by the WHO which it suitably completes. Acute toxicity makes it possible to classify pesticides into five classes: class I - highly toxic, class II - toxic, class III - moderately toxic, class IV - slightly toxic, class V - virtually non-toxic. Skin irritation enabled to classify pesticides as highly irritant, irritant, moderately irritant, slightly irritant and non-irritant. For skin toxicity 3 degrees were used: those of very good resorption, good resorption and low resorption. The proposition fr classification is supplemented by cummulation coefficient and the aspect of chronic effect. In the present study the authors call for further search for the criteria of pesticide classification and draw attention to some pesticides, discussing their re-classification into higher classification classes.

Clinical and laboratory findings in Metation EK-50.

Authors present some of their results from an epidemiological study on the effect of fenitrothion (Metation EK-50) on the organism of occupationally exposed workers in the production of this preparation and in female workers in the packing room during a 5-year period. The results of clinical examinations pointed to parasympathetic stimulation and disposition to hypotonia. Neurological and psychiatric findings revealed a low-grade pseudoneurasthenic syndrome in 33% of females and in 15% of males. The results of psychodiagnostic tests after the exposure to fenitrothion and its intermediate products showed partial deterioration of retention, impairment of visuomotor coordination of movements in tapping and that or orientation readiness, prolonged average time of decision-making and prolonged average reaction time for complex sensorimotor responses. From among the biochemical parameters after the exposure to fenitrothion the following ones can be mentioned: inhibition of cholinesterase in blood, increase of GPT transaminase, increase of insoenzyme LDH5 and changes in protein fractions, as statistically significant (P less than 0,001). The values of excreted p-nitro-m-cresol (NC) in urine in males after the exposure to fenitrothion were 5,61 mg/l on the average, compared with the average value of 1,54 mg NC/l before exposure. The average values of excreted NC in urine in females involved in bottling Metation were those of 4,0 mg NC or 6,58 mg NC/l of urine after exposure. The concentration of fenitrotrion in the air of the working space ranged from 0,028 to 0,118 mg X m-3. From the values of the excreted NC in urine in the exposed workers and in volunteers, to whom fenitrothion was administered in the doses of 2,5 to 20 mg, it can be judged that the organism of exposed workers received approximately 15 mg of fenitrothion per capita a day and those of exposed females 20 mg or more per capita a day.