Enzyme-selective effects of nitric oxide on affinity and maximum velocity of various rat cytochromes P450.

Nitric oxide (NO) has recently been shown to decrease cytochrome P450 (P450) enzyme activity rapidly (< or =30 min), concentration dependently, and enzyme-selectively in the rat liver. Interestingly, among all the studied P450 enzymes, only CYP2D1 was not affected by NO donors. However, these studies were conducted using only a single concentration of the substrates, thus lacking information about the possible simultaneous changes in both maximum velocity (Vmax) and affinity (Km) of the enzymes. In the present study, we systematically evaluated the effects of NO on the enzyme kinetic parameters of marker substrates for a range of P450 enzymes, including 2D1. Livers were perfused (1 h) in the absence (control) or presence of two NO donors with different mechanisms of NO release. At the end of the perfusion, microsomes were prepared and used for kinetic analysis. Except for 2D1, NO reduced the Vmax of all the model reactions studied, although to a varying degree. However, the effects of NO donors on Km were more diverse. Whereas the Km values for testosterone 6beta-hydroxylation (3A2) and 16alpha-hydroxylation (2C11) significantly decreased, the values for chlorzoxazone 6-hydroxylation (2E1), dextromethorphan N-demethylation (3A2), and high affinity ethoxyresorufin O-dealkylation (1A1/2) significantly increased in the presence of NO donors. Furthermore, the Km values for the high-affinity component of dextromethorphan O-demethylation and benzyloxyresorufin O-dealkylation remained unchanged. These results indicate that NO can potentially change both the Vmax and Km of various substrates selectively and confirm our previous findings that the activity of CYP2D1 is not affected by NO donors.     

Neoplastic diseases of the head & neck in children

Pediatric neoplasm is next only to trauma as the most common cause of death. The cervicofacial malignancies presents a unique challenge owing to potential adverse effects of both the disease process and the treatment employed on critical developing head and neck structures. This study comprised of 106 children below 12 years age group conducted during 1999–2003 at JNMC, Aligarh. Of 106 cases 70 were benign neoplasms and 36 malignant neoplasms. Nasopharynx was the commonest site of involvement. Nasopharyngeal angiofibroma was the commonest benign tumour and lymphoma was the commonest malignant neoplasm. Team approach is required for mitigation of the disease process.     

Clinicopathological findings of a natural outbreak of Theileria annulata in cattle: an emerging disease in southern Iran

Theileriosis is an economically important hemoprotozoal disease with high morbidity and mortality in cattle. The present study reported the pathological features of a natural outbreak of tropical bovine theileriosis due to Theileria annulata in Fars Province, southern Iran. T. annulata was confirmed by the presence of T. annulata piroplasms in the blood smears and also by polymerase chain reaction test. On necropsy, pale mucous membranes and petechial and ecchymotic hemorrhages in the mucosal and serosal surfaces together with lymphadenopathy were observed. The liver was friable, yellowish, and larger than normal. Hemorrhages and punched-out ulcers were observed in the abomasal mucous membrane. Severe petechial hemorrhages were seen in the skin particularly in the hairless areas. Pulmonary edema and emphysema with petechial and ecchymotic hemorrhagic foci in the lungs were evident. The main histological changes were proliferation of lymphocytes in the lymph nodes and proliferation of macrophages, lymphocytes, and plasma cells in the spleen, Peyer's patches, portal tracts of the liver, and interstitial tissue of the kidneys. The mucous membrane of the abomasum showed numerous multifocal areas of necrosis and ulceration, and the submucosal area and lamina propria adjacent to these lesions showed hyperemia and hemorrhages, with mononuclear cell infiltration. The skin showed multifocal necrotic changes, petechial and ecchymotic hemorrhages, and chronic dermatitis. The schizonts of Theileria were evident in the cytoplasm of the lymphocytes and macrophages of the lymph nodes, spleen, and skin. Molecular examination revealed that these animals were infected with T. annulata. The present study describes the clinicopathological findings of bovine tropical theileriosis in an unpredictable weather condition.     

The role of peer support education model on the quality of life and self-care behaviors of patients with myocardial infarction

ObjectiveThis study aimed to assess the effect of peer education on the quality of life and self-care behaviors of patients with myocardial infarction.MethodsIn this clinical trial, 70 patients with myocardial infarction meeting the inclusion criteria were assigned to experimental (n = 35) or control (n = 35) groups using block randomization. Patients in the intervention group received two one-hour training sessions on the third day after myocardial infarction during the CCU stay along with routine care. Education intervention was performed by peers. The control group will follow routine care. All patients selected were assessed using McNews' quality of life questionnaire and Miller self-care questionnaire, respectively before the intervention and also one month after discharge. Chi-square and t-test were used to analyze the data.ResultsAfter the intervention, the mean of quality of life and the mean score of self-care behaviors in the experimental group were significantly higher compared to the control group.ConclusionsAccording to the results, to improve the quality of life and promote the self-care behaviors in such patients, using peer education along with healthcare professionals is recommended.Practice ImplicationThis patient education approach had a significant impact on quality of life and self-care behavior.     

Comparison of radiographic and magnetic resonance imaging findings of early osteoarthritis of the rabbit knees: an experimental study

The objectives of the present study were to describe radiographic and magnetic resonance imaging (MRI) findings of early osteoarthritis and their relationships at the same time. A total number of ten rabbits were used and randomly divided into two equal groups. In one group, cranial cruciate ligament (CCL) of the left knee was transected to produce experimental osteoarthritis and in the other group, only the articular capsule was entered as sham operation (arthrotomy group). All of the left knees were examined by MRI and radiography before operation to exclude preexisting abnormalities and serve as control. One month postoperation, two conventional radiographic views and MR imaging were performed under general anesthesia. Statistical analysis of the MRI results revealed that there was a significant difference between the CCL-transected group with arthrotomy and control groups. There was no significant difference in the radiographic findings between the operated, arthrotomy and control groups. It was concluded that osteoarthritic changes of the joints can be detectable 1?month postinjury by MRI. Meniscal degeneration and subchondral bone irregularity are detectable diagnostic signs.     

Myxopapillary ependymoma of the conus medullaris presenting with intratumoral hemorrhage during weight lifting in a teenager

Intratumoral hemorrhage within a myxopapillary ependymoma of the conus medullaris and cauda equina is rare. Most patients with myxopapillary ependymoma present insidiously, but they may present with hemorrhage or cauda equina syndrome. Limited number of case reports available has described this condition only in adult patients. We report our experience with intratumoral hemorrhage of myxopapillary ependymoma of the conus medullaris during weight lifting in a 15-year-old boy.     

Disturbance of zinc and glucose homeostasis by methyl tert-butyl ether (MTBE); evidence for type 2 diabetes

1.?The prevalence of diabetes and the other metabolic disorders has noticeably increased worldwide. A causal link between increasing risk of type 2 diabetes and exposure to environmental pollutants has been reported.

2.?We hypothesized that exposure to methyl tert-butyl ether (MTBE), an oxygenate additive to gasoline would hinder zinc and glucose homeostasis in rats.

3.?Male Sprague–Dawley rats received MTBE in drinking water for 90 days. At the end of the treatment, pancreas and blood samples were collected for biochemical and molecular examinations. Expression of four candidate genes, including Insulin1, Insulin2, MT1A, SLC30A8 by Real-Time Quantitative PCR (Q-PCR) as well as biochemical parameters, including fasting blood glucose (FBS), triglycerides (TG), cholesterol (CHO), low-density lipoprotein (LDL), high-density lipoprotein (HDL), copper (Cu²⁺) and calcium (Ca²⁺) levels as well as High-sensitive C-reactive protein were assessed as endpoints.

4.?This study suggested that MTBE exposure can be associated with disruption in zinc homeostasis and glucose tolerance.