Constitutive Serotonin Tone Modulates Molecular and Behavioral Response to Chronic Fluoxetine Treatment: A Study on Genetic Rat Model.

Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed medications for the treatment of mood disorders. Yet, individual response to SSRIs is highly variable, with only a portion of patients showing the desired therapeutic effect. To better understand the molecular basis underlying individual variability in response to SSRIs, here we comparatively studied behavioral and molecular consequences of chronic treatment with fluoxetine, a widely used SSRI, in two sublines of rats with constitutionally different serotonin (5HT) homeostasis: the high-5HT and low-5HT sublines. Platelet 5HT levels, a recognized indicator of SSRI efficacy, were decreased by fluoxetine treatment in both 5HT-sublines. On the other hand, biologically active plasma 5HT levels were reduced only in high-5HT rats. The anxiolytic effect of fluoxetine was also evident only in high-5HT rats, as supported by spatio-temporal and ethological behavioral measures in the elevated plus maze (EPM) test and exploratory behavior measures in the open field (OF) test. None of the behavioral EPM or OF measures were significantly altered by fluoxetine treatment in low-5HT rats. Unexpectedly, 5HT levels in cerebral cortices tended to be reduced only in low-5HT rats. Moreover, the effects of fluoxetine on cortical expression levels of 5HT-related proteins were also present only in low-5HT rats, with serotonin transporter (5HTT) and serotonin receptor type 1a (Htr1a) being down-regulated, while serotonin receptor type 4 (Htr4) was up-regulated by fluoxetine treatment. The obtained results support a role of individual 5HT tone as an important influencing factor on the biological actions of SSRI antidepressants.

Successful Treatment of Disseminated Bacillus Calmette-Guérin Disease in an HIV-Infected Child with a Linezolid-Containing Regimen.

Upon HIV infection diagnosis, an 8-month-old boy was transferred for evaluation of worsening respiratory distress requiring mechanical ventilation. Pneumocystis jirovecii pneumonia (PCP) was diagnosed; the boy also had a nonhealing ulcer at the site of vaccination with Statens Serum Institut (Danish strain) Bacillus Calmette-Guérin (BCG) vaccine and associated axillary lymphadenopathy. PCP treatment resulted in weaning from mechanical ventilation. Antimycobacterial treatment was immediately attempted but was discontinued because of hepatotoxicity. Over several months, he developed splenic lesions and then disseminated skin and cystic bone lesions. M. bovis was repeatedly cultured from both skin and bone lesions despite various multidrug antimycobacterial regimens which included linezolid. Eventually, treatment with a regimen of rifabutin, isoniazid, ethambutol, and linezolid led to definitive cure. Clinicians should consider a linezolid-containing regimen for treatment of severe disseminated BCG infection, especially if other drug regimens have failed. Although drug toxicity is a particular concern for young children, this patient received linezolid for 13 months without serious toxicity. This case also highlights the need for universal screening among pregnant women to prevent vertical transmission of HIV. Finally, routine immunization with BCG vaccine at birth should be questioned in countries with low and declining burden of tuberculosis.

Experimental Spinal Stenosis in Cats: New Insight in Mechanisms of Hydrocephalus Development.

In our new experimental model of cervical stenosis without inflammation we have tested hypothesis that cranio-spinal communication impairment could lead to hydrocephalus development. Spinal and cranial cerebrospinal fluid (CSF) space separation was obtained with positioning of plastic semiring in epidural space at C2 level in cats. Brain ventricles planimetry, and CSF pressure recording in lateral ventricle (LV) and lumbar subarachnoid space (LSS) were performed in acute and subchronic experiments. In all experiments opening CSF pressures were normal. However, in acute experiments, an infusion of artificial CSF into the LV led to increase of CSF pressure and significant gradient pressure development between LV and LSS due to limited pressure transmission. After 3 or 6 weeks spinal cord atrophy was observed at the site of cervical stenosis, and pressure transmission from LV to LSS was improved as a consequence of spinal tissue atrophy. Planimetry of both the coronal brain slices and the ventricles' surface showed that control ventricular surface was 0.6 ± 0.1% (n = 5), and 1.6 ± 0.2% (n = 4) in animals with subchronic cervical stenosis (P < 0.002). These results support the mentioned hypothesis claiming that CSF volume cranio-spinal displacement impairment could start pathophysiological processes leading to development of hydrocephalus.

Risk factors for coronary artery abnormalities in children with Kawasaki disease: a 10-year experience.

Kawasaki disease (KD) is an acute systemic vasculitis of childhood. Due to development of coronary artery aneurysms (CAA) it is considered the most common cause of acquired heart disease in children. The clinical and laboratory features of patients with complete and incomplete KD were compared in order to identify the possible predictors of CAA development. A cross-sectional study of children with KD treated at the University Hospital for Infectious Diseases, Zagreb, between January 2003 and December 2012 was conducted. A total of 111 KD patients were included; 70.3% patients had complete KD. Patients with complete KD had more frequently rash, changes on extremities and mucous membranes, as well as higher serum bilirubin, aminotransferases, gamma-glutamyl transferase and lactate dehydrogenase levels. Patients with incomplete KD had longer duration of fever before the diagnosis (8 vs. 7 days) and delayed IVIG treatment (day 8 vs. 7). CAA was detected in seven children (6.3%). Disease duration before hospitalization >6 days (OR 7.16, 95% CI 1.51-100.35), age <6 months (OR 25.86, 95% CI 1.68-398.35) and platelet count >771 after the 7th day of disease (OR 13.33, 95% CI 2.19-80.87) were independently associated with CAA development. The diagnosis and treatment in incomplete KD can be delayed due to the absence of major criteria. Age, duration of symptoms prior hospitalization and platelet count were identified as independent predictors of CAA development.

Ischemic stroke associated with adenoviral infection in a 4-year-old boy.

We present a case of childhood arterial ischemic stroke associated with proven adenoviral upper respiratory tract infection in a previously healthy 4-year-old boy. Adenoviral meningitis and encephalitis have been reported repeatedly, thus confirming the neuroinvasive capability of these viruses. However, an association between adenoviral infection and arterial ischemic stroke has not been described thus far. HIV and varicella zoster virus are the only microorganisms that have been consistently associated with arterial ischemic stroke in the absence of acute central nervous system infection. In HIV-infected individuals ischemic stroke can be caused by vasculitis and hypercoagulability. Granulomatous arteritis of the vessel wall causes post-varicella cerebral infarction and ischemic stroke after herpes zoster ophthalmicus. We suggest that in our patient a post-varicella cerebral infarction-like mechanism of adenoviral spread to the affected artery wall occurred through the ophthalmic branch of the trigeminal nerve. Adenoviruses are neuroinvasive and inflamed conjunctiva might have permitted introduction of the virus into ophthalmic nerve tissue. In consequence, the stenotic lesion of the artery might have been induced by the presence of adenovirus and the subsequent inflammatory reaction. We recommend a prompt quest for adenoviral infection in all previously healthy children with fever and clinical presentation compatible with ischemic stroke, because timely diagnosis and treatment could improve the outcome and hasten neurological recovery.

Rhabdomyolysis and acute renal failure in a child with para-influenza type 1 infection.

We present a rare case of para-influenza type 1 virus-induced rhabdomyolysis, complicated by acute renal failure (ARF). The child underwent continuous venovenous haemofiltration and has shown full clinical and biochemical recovery. ARF due to rhabdomyolysis in para-influenza type 1 infection in a child has, to the best of our knowledge, not been previously reported.

McKittrick-Wheelock syndrome: a rare cause of diarrhoea.

McKittrick-Wheelock syndrome is a rare disorder caused by fluid and electrolyte hypersecretion from a rectal tumour. The most frequently reported tumours are villous adenomas. Dehydration with severe hyponatremia, hypokalemia, metabolic acidosis, acute renal failure and watery diarrhoea is typical. The authors present a case of McKittrick-Wheelock syndrome caused by rectal adenocarcinoma.