Effect of CYP4F2, VKORC1, and CYP2C9 in Influencing Coumarin Dose: A Single-Patient Data Meta-Analysis in More Than 15,000 Individuals

The cytochrome P450 (CYP)4F2 gene is known to influence mean coumarin dose. The aim of the present study was to undertake a meta-analysis at the individual patients level to capture the possible effect of ethnicity, gene-gene interaction, or other drugs on the association and to verify if inclusion of CYP4F2*3 variant into dosing algorithms improves the prediction of mean coumarin dose. We asked the authors of our previous meta-analysis (30 articles) and of 38 new articles retrieved by a systematic review to send us individual patients' data. The final collection consists of 15,754 patients split into a derivation and validation cohort. The CYP4F2*3 polymorphism was consistently associated with an increase in mean coumarin dose (+9% (95% confidence interval (CI) 7-10%), with a higher effect in women, in patients taking acenocoumarol, and in white patients. The inclusion of the CYP4F2*3 in dosing algorithms slightly improved the prediction of stable coumarin dose. New pharmacogenetic equations potentially useful for clinical practice were derived.

In vitro effects of famotidine and ranitidine on lower esophageal sphincter tone in rats

BACKGROUND/AIMS

The aim of this study was to investigate the effects of the H2 receptor antagonists famotidine and ranitidine on lower esophageal sphincter pressure in the rat isolated lower esophageal sphincter preparation contracted with carbachol.

MATERIALS AND METHODS

Lower esophageal sphincter tissues of eight rats for each group were placed in a standard organ bath. After contraction with carbachol, freshly prepared famotidine and ranitidine were added directly to the tissue bath in cumulatively increasing concentrations. Activities were recorded on an online computer using the software BSL PRO v 3.7, which also analyzed the data.

RESULTS

Ranitidine caused a small statistically insignificant relaxation in the contracted lower esophageal sphincter at the two applied concentrations. Although 1.5 x 10⁻⁵ M famotidine did not cause a significant relaxation in lower esophageal sphincter tone, this value for 4.5 x 10⁻⁵ M famotidine was 9.33%, and the relaxation was significant when compared with controls (p<0.05).

CONCLUSIONS

Neither famotidine nor ranitidine caused any direct significant change in lower esophageal sphincter tone in the therapeutic dose range applied to the organ bath. However, the higher dose of famotidine caused a significant relaxation in the lower esophageal sphincter tone. Further in vivo human studies may affect the usage of these drugs during gastroesophageal reflux disease treatment.

The effects of chronic administration of sumatriptan and dipyrone on serotonergic system in the rat brain: an immunohistochemical study

OBJECTIVE

To investigate the effects of chronic high dose sumatriptan and dipyrone treatment on central serotonergic system in rats.

MATERIALS AND METHODS

Male Sprague-Dawley rats (seven per group) were daily injected with sumatriptan (3 mg/kg), dipyrone (400 mg/kg) or saline for 30 days. The brains of animals were surgically removed and immunohistochemically stained for serotonin. Serotonin-positive stained cells were counted automatically by using a computerized image analysis program. Statistical analysis carried out using one-way ANOVA followed by post hoc Tukey test.

RESULTS

A significant decrease in serotonin-positive cells in the brainstem was observed after chronic sumatriptan administration while chronic use of dipyrone induced a significant increase in serotonin-positive cells both in the cortex and midbrain.

CONCLUSION

Our data suggest that central serotonergic system might be modified by chronic use of sumatriptan and dipyrone.

Role of diffusion-weighted MR in differential diagnosis of intracranial cystic lesions

AIM

The purpose of this study was to evaluate the role of diffusion-weighted imaging (DWI) in characterizing cerebral cystic lesions. The usefulness of the apparent diffusion coefficient (ADC) map in lesion characterization was also evaluated.

METHODS

We compared the findings of conventional MR images with those of DWI: 63 cystic masses in 48 patients were examined with routine MR imaging and echo-planar DWI. The routine MR imaging included at least the axial T2- and T1-weighted sequences, and post-contrast T1 axial sequences. The DWI included an echo-planar spin-echo sequence with three values (0, 500 and 1000s/mm(2)) sensitizing gradient in the x, y, z direction, and it obtained an ADC map.

RESULTS

The sensitivity of DWI for differentiating abscesses from primary brain tumours was 100%; for differentiating abscesses from metastatic tumours was 73%; for differentiating benign from malignant lesions was 90%.

CONCLUSION

Although some metastatic lesions may appear hyperintense on DWI thus imitating an abscess, evaluation of the lesions with both DWI and conventional MRI may have an important contribution to the differentiation of tumours from abscesses.

Musicogenic epilepsy with ictal single photon emission computed tomography (SPECT): could these cases contribute to our knowledge of music processing?

Musicogenic epilepsy has a strong correlation with the temporal lobe with a right-sided preponderance. We report the case of a 48-year-old woman whose seizures began at the age of 32 years. Her prenatal, natal and childhood histories were unremarkable and her family history was negative for epilepsy. She had typical complex partial seizures with chewing automatisms. Cranial computed tomography, magnetic resonance imaging (MRI) and interictal SPECT showed no abnormality. Interictal EEG showed paroxysmal bitemporal sharp wave discharges predominant on the right side. Ictal EEG showed a combination of high voltage sharp and slow sharp waves and spikes that originated from the right temporal leads and then became generalized. Ictal activity on EEG started 4-5 min after the music stimulus. For the ictal SPECT study, i.v. injection of 20 mCi of HMPAO was administered approximately 30 s after the ictal activity started. Ictal SPECT demonstrated a right anterior and mesial temporal hyperperfusion. These results seem to support the dominant role of the right temporal lobe and the possible relation of mesial temporal structures to the affective content of music in musicogenic epilepsy.

Diagnostic value of troponin T in neonates of mild pre-eclamptic mothers

The measurement of myocardial damage by newer, highly specific markers of myocardial damage is now possible, including cardiac structural proteins such as troponin T (TnT). In neonates of pre-eclamptic mothers, it identifies minor myocardial damage missed by other biochemical markers. The present study was designed to determine the diagnostic value of TnT concentrations in neonates of pre-eclamptic mothers. Fifteen neonates of pre-eclamptic mothers were studied (9 boys and 6 girls), and 17 healthy full-term neonates (9 boys and 8 girls) were selected as a control group. The serum TnT concentration in neonates of pre-eclamptic mothers (0.70 ng/ml) was significantly higher than that in the control group (0.10 ng/ml). In an echocardiographic study, the mean mitral peak velocity at an atrial contraction (A) value of 39 cm/s in neonates of pre-eclamptic mothers was significantly lower than that in the control group (53 cm/s), and the mean mitral peak velocity of early diastole to peak velocity of the atrial contraction (E/A) value (1.75) in neonates of pre-eclamptic mothers was significantly higher than that in the control subjects (1.23). In conclusion, our study demonstrated high levels of cardiac TnT, lower mitral A values and high mitral E/A values in neonates of pre-eclamptic mothers, presumably associated with mild myocardial damage in the neonates of pre-eclamptic mothers.

Prognostic value of p53, proliferating cell nuclear antigen, and Ki-67 expression in undifferentiated nasopharyngeal carcinomas

In this study the prognostic importance of p53, proliferating cell nuclear antigen (PCNA), and Ki-67 expression was analyzed along with the clinical parameters in 35 consecutive patients with undifferentiated nasopharyngeal carcinomas. Immunohistochemistry was used to detect p53, PCNA, and Ki-67 staining. Among the clinical findings, stage IV disease (P = 0.01), cranial nerve paralysis (P = 0.02), and lymph node metastasis (P = 0.06) were associated with shorter survival. The p53 positivity correlated with the presence of lymph nodes, but it was not a significant factor to predict the outcome. PCNA expression was not found to be a prognostic indicator. On the other hand, the proliferative value of Ki-67 staining was suggestive of prognosis. A proliferation index of Ki-67 less than 10% indicated longer survival (P = 0.03). There was no correlation between Ki-67 staining and PCNA index. As a result, the prognostic value of Ki-67 may alert the physician to more aggressive and adjuvant treatment modalities.

Thyroid function tests in the newborn infants of preeclamptic women

The purpose of this study was to identify possible changes in thyroid functions in newborn infants of preeclamptic women. Fifteen neonates (nine boys and six girls) of preeclamptic women and 17 healthy neonates (nine boys and eight girls) for the control group were included in the study. Serum thyroid-stimulating hormone (TSH), total triiodothyronine (TT3) and total thyroxine (TT4) levels and thyroid gland volumes were determined in both groups. Serum TSH and TT4 levels were not statistically different between the two groups. However, serum TT3 level was 79.22 +/- 40.19 ng/dl in the study group and 40.00 +/- 15.99 ng/dl in control subjects (p < 0.01). The mean right, left and total thyroid volumes were 1.3 +/- 1.2 ml, 1.2 +/- 1.1 ml and 2.4 +/- 2.3 ml in the study group and 0.6 +/- 0.2 ml, 0.6 +/- 0.2 ml, and 1.1 +/- 0.4 ml in the control group, respectively (p < 0.05). The mean thyroid volume/body weight was 0.9 +/- 0.09 ml/kg in the study group and 0.3 +/- 0.06 ml/kg in the control group (p < 0.05). In conclusion, we would like to stress that preeclampsia might be a cause of fetal and neonatal thyroid enlargement and elevated serum TT3 level.

Cherubism: a radiological and clinical presentation

Cherubism is the hereditary form of the fibrous dysplasia of the jaws, but it may be seen sporadically as well. The disease has a self-limited nature and is rarely apparent before the age of two. There is no need to interfere surgically with these lesions of the mandible or the maxilla unless the child is severely affected, i.e. the disease deteriorates respiration, deglutition, vision, or the psychiatric makeup of the child due to cosmetic reasons. The clinical presentation and radiological evaluation of these children are so typical that the pediatrician and pediatric otolaryngologist need to be informed about this rarely seen disease. A case of a cherubic child, with his clinical appearance as well as his radiological evaluation, and discussion about the clinical outcome are presented.

Persistent neonatal hypoglycemia: an unusual finding of congenital hypothyroidism

We report a newborn infant who has congenital hypothyroidism associated with profound and persistent neonatal hypoglycemia. Persistent and marked hypoglycemia has not been previously reported in congenital hypothyroidism to our knowledge. The cause of this condition may be reduced glyconeogenesis or insulin clearance.

A venous anomaly of the neck

Vascular anomalies localize mostly in the head and neck region. Besides the complications they present, when they are left untouched, they are cosmetically ugly. A vascular lesion in any part of the body of a child is always bothersome to the parents and may be a problem for the family. The confusion about classification of these lesions and the delay in seeing the physician may adversely affect the child also. There has been a debate concerning the classification of vascular malformations, their clinical presentation, and their treatment modalities. In this paper we reviewed the classification as accepted in the literature and presented a case of huge venous anomaly in the neck region with its angiographic and MRI views and discussed the possible complications and modes of treatment.

Naloxone and lithium interaction on the levels of homovanillic acid in the rat brain

The effects of long term (10 days) treatment of lithium and naloxone on HVA levels of striatum, hypothalamus and frontal cortex in rats were investigated. Lithium (400 mg/l in drinking water) itself had no effect on HVA levels of any region. Naloxone (2 mg/kg) treatment caused significant increases in the levels of HVA in hypothalamus and striatum and lithium cotreatment prevented the effect of naloxone. Neither of those were observed in the frontal cortical region.

Effect of naloxone on apomorphine-induced changes in locomotor activity of stress-exposed rats

Acute and subacute effects of naloxone (10 mg/kg), apomorphine (0.125 mg/kg; 5 mg/kg) and stressful stimuli (immobilization, cold and sound) on locomotor activity were examined. In both acute and subacute (8 days) treatments, the lower dose of apomorphine decreased locomotor activity and the higher dose of apomorphine increased it. In the acute treatment, naloxone enhanced significantly the depressant effect of the lower dose of apomorphine on locomotor activity. Stress seemed to have no effect on apomorphine induced changes in locomotor activity of rats either in acute or in subacute treatment.

Motility, rigidity and turnover of dopamine in the striatum after administration of morphine to rats: a re-evaluation of their mechanisms

Whether the delayed behavioural activation and the increase in dopamine (DA) turnover in the striatum reflect signs of rebound effects or of counter-regulatory processes directed against locomotor depression and/or muscular rigidity was studied in rats. Administration of a large dose of morphine (30 mg/kg i.p.) induced strong muscular rigidity, which was measured as tonic activity in the electromyogram (EMG). This effect was maximal after one hour and disappeared during the fourth hour. The locomotor activity, on the other hand, disappeared after 30 min and re-appeared during the fourth hour, followed by a locomotor stimulation with a maximum after 4.5 hr. Striatal lesions produced with kainic acid did not affect the complete locomotor depression (akinesia), except by slightly prolonging this effect, and did not influence the delayed locomotor stimulation. These lesions did not inhibit, but, on the contrary, enhanced the increase in striatal concentration of 3,4-dihydroxyphenylacetic acid (DOPAC). Injections of morphine (10 micrograms) into the substantia nigra led to an increase in the level of DOPAC in the ipsilateral, but not the contralateral striatum. These results, in conjunction with those of other authors, suggest that the increase in DA turnover in the striatum and the delayed locomotor stimulation ought to be regarded as actions of morphine on sites different from those mediating muscular rigidity.

Effects of striatal lesions with kainic acid on morphine-induced "catatonia" and increase of striatal dopamine turnover

The influence of striatal lesions (head of the caudate nucleus) with kainic acid on "catatonia" and on the increase of the dopamine metabolite DOPAC in the striatum after systemic morphine administration was measured in rats. These lesions strongly prevented the morphine-induced muscular rigidity, measured as activity in the electromyogram EMG) of the gastrocnemius-soleus muscle of non-anesthesized animals. On the other hand, the decrease of locomotion (akinesia) measured using an Animex Activity Meter and an activity wheel, was not prevented or reduced. The lesions did not influence the inhibitory effect of morphine on the activation of flexor alpha-motoneurones, either. These results suggest that the head of the caudate nucleus plays an important role in mediating morphine rigidity, but not akinesia or inhibition of the activation of flexor alpha-motoneurones. Opioid-induced "catatonia" ought to be regarded as a mixture both of rigidity and of akinesia. Morphine led to a rapid decrease, followed by a slow increase of striatal DOPAC concentration. Lesions induced by kainic acid slightly inhibited the decrease and markedly enhanced the increase of DOPAC. Accordingly, an intact nigro-striato-nigral loop is not necessary for the increase of striatal dopamine turnover, observed after morphine administration. The different sites of action, which are likely to mediate all these effects of morphine, are discussed.

Effect of chronic administration of morphine on primary immune response in mice

The effect of 3 different doses of chronically-administered morphine on the primary immune response was studied in mice by estimating spleen/body weight ratio and serum hemolysin production against sheep red blood cells (SRBC). It was observed that morphine exerted a dose-dependent inhibitory effect on the immune response which was antagonized by the concomitant administration of naloxone. The findings suggest that the inhibitory effect of morphine is specific.