Marina Bralic

Incomplete block of B cell development and immunoglobulin production in mice carrying the ? MT mutation on the BALB/c background

The expression of the preB cell receptor (preBCR), composed of the μ  chain, surrogate light chains and the Igα /Igβ  signal transduction unit, permits further differentiation of Bcell precursors. C57BL/6 mice homozygous for an inactivating mutation of the membrane exon of the μ  chain gene (C57BL/6μ MT/μ MT) cannot form a preBCR and are, consequently, devoid of mature B lymphocytes. Here we present evidence that the block of B cell development by the μ MT mutation is incomplete in BALB/c mice. Unlike C57BL/6μ MT/μ MT, BALB/cμ MT/μ MT mice generate small numbers of mature B cells, accumulate plasma cells and produce high levels of all immunoglobulin isotypes, except IgM. The observed phenomenon seems to be controlled by a single genetic locus that is not linked to IgH.

Altered development of the brain after focal herpesvirus infection of the central nervous system

Human cytomegalovirus infection of the developing central nervous system (CNS) is a major cause of neurological damage in newborn infants and children. To investigate the pathogenesis of this human infection, we developed a mouse model of infection in the developing CNS. Intraperitoneal inoculation of newborn animals with murine cytomegalovirus resulted in virus replication in the liver followed by virus spread to the brain. Virus infection of the CNS was associated with the induction of inflammatory responses, including the induction of a large number of interferon-stimulated genes and histological evidence of focal encephalitis with recruitment of mononuclear cells to foci containing virus-infected cells. The morphogenesis of the cerebellum was delayed in infected animals. The defects in cerebellar development in infected animals were generalized and, although correlated temporally with virus replication and CNS inflammation, spatially unrelated to foci of virus-infected cells. Specific defects included decreased granular neuron proliferation and migration, expression of differentiation markers, and activation of neurotrophin receptors. These findings suggested that in the developing CNS, focal virus infection and induction of inflammatory responses in resident and infiltrating mononuclear cells resulted in delayed cerebellar morphogenesis.

Suicidal drowning in Southwestern Croatia: a 25-year review.

We designed a retrospective study to analyze suicidal drowning deaths occurring between 1981 and 2005. During the study period there were 134 cases of suicidal drowning accounting 10% of all suicides, and 31% of all drowning deaths. Of the 134 drowning suicides, 76 (57%) incidents occurred in the sea, 46 (34%) in water wells, 8 (6%) in rivers, and 4 (3%) in bathtubs. During the study period, cases of suicidal drowning were not identified in males and females under the age of 20. In females aged 65 years and older, drowning represents the most common type of suicide. Commonly, the victims were sober at the time of the incident. Cases of suicidal drowning committed in water wells are unexpectedly high, considering abundance of salt water.

Targeted wire-guided chest tube placement: a cadaver study.

Objective Chest tube thoracostomy is a standard procedure for pleural fluid and air drainage. The aim of this study is to compare the success rate of the targeted tube thoracostomy using two different techniques: a targeted wire-guided (TWG) technique and a classical surgical (CS) technique. Methods The study was performed on 153 human cadavers without documented pleural pathology, mechanically ventilated during the procedure. They were divided into two groups and to each cadaver a software generated random number was assigned. The TWG technique was applied on 76 and the CS technique on 77 cadavers. The TWG and CS groups were divided into four subgroups according to the four intended positions of the chest tube tip (target position in the pleural cavity): back-down-right, front-up-right, front-up-left and back-down-left. The precise position of the chest tube tip after thoracostomy was determined by autopsy. The placement of the thoracostomy tube was marked successful if the chest tube tip was located at an intended position. Results The success rate with the TWG technique was 79%, whereas with the CS technique it was 30%. Conclusion A higher success rate was achieved with the TWG than with the CS thoracostomy technique.

Pneumocephalus after an uneventful scuba dive.

Scuba diving has become increasingly popular in the last 20 yr. Although it is considered safe, accidents, sometimes with fatal outcomes, do occur. The incidence of diving-related CNS barotrauma is low and it has been reported very infrequently. The clinical presentation may range from minimal dysesthesias to complete quadriplegia, encephalopathy, or death. In this paper we present a case of pneumocephalus in a 36-yr-old male scuba diver that presented with minor neurologic symptoms. A discussion, including a review of the literature, is also presented. The authors recommend that diving-induced neurologic dysbarism syndromes, including pneumocephalus, should be considered a possible cause when a scuba diver presents with neurologic symptoms, even minor ones.

Hemodynamic changes in the posterior cerebral circulation triggered by insufficient sympathetic innervation--cause of primary intracerebral hemorrhage?

Primary intracerebral hemorrhage (ICH) is caused by hypertensive disease of small penetrating blood vessels in the basal ganglia, brain stem and cerebellum. Those regions are supplied by arteries of the so-called posterior brain circulation with insufficient sympathetic innervation. We propose the following hypothesis: due to insufficient sympathetic innervation hemodynamic changes occur in the vascular bed of the posterior brain circulation serving as a key factor for arterial rupture. If autoregulation is insufficient to maintain normal cerebral blood flow, in abrupt rise in the blood pressure, the amount of blood is rising causing higher static pressure, and according to Laplaces law higher pressure and larger radius leads to higher wall tension and subsequent rupture of arterial wall previously weakened by prolonged hypertension.

Neurogenic pulmonary edema caused by bilateral medial medullary infarction

Sir, Neurogenic pulmonary edema (NPE) is a clinical syndrome characterized by the acute onset of pulmonary edema following a significant central nervous system (CNS) lesion in the absence of cardiopulmonary disease [1, 2]. In most cases the precise CNS lesion site directly associated with NPE could not be identified. According to some case reports and animal experiments these ‘NPE trigger zones’ include the hypothalamus and the medulla [3–5]. We report a case where NPE was induced by a bilateral medial medullary infarction (BMMI), a rare stroke syndrome per se. A 63-year-old man diagnosed with hypertension was referred to our hospital with symptoms of vertigo, vomiting and tingling of the left side of the body. The symptoms occurred 2 h prior to admission. He became soporous (Glasgow Coma Scale 10) and developed acute respiratory failure. He was analgosedated, endotracheally intubated and mechanically ventilated. On admission, his blood pressure was 170/100 mmHg, pulse was 98/min, and body temperature was 36.3 C. Laboratory values and head CT were normal. A simple neurological examination (‘‘diagnostic window’’) was undertaken. The patient was alert, pupils and eye movements were normal. Right beating nystagmus on right gaze was present. Facial sense and movement were not impaired. He was tetraparetic with dominant weakness and hypoesthesia of the left side of the body. The deep tendon reflexes were enhanced and Babinski’s sign was present bilaterally. On hospital day 5 the patient was weaned from the ventilator and extubated. His breathing was irregular and dyspneic. He was analgosedated, re-intubated and set on lung protective ventilation. Chest radiograph indicated findings consistent with pulmonary edema (Fig. 1a). Tracheotomy was performed. Weaning procedures were unsuccessfully attempted two more times. Finally, he was successfully weaned from the ventilator on the 24th day of his illness. The patient then underwent brain magnetic resonance imaging (MRI) which revealed signal changes at the level of the bilateral medial medulla along with tissue loss. On the basis of these findings, BMMI was suggested (Fig. 1b). Neurological symptoms gradually regressed, although mild tetraparesis remained. The patient was transferred to a different facility to continue rehabilitation. On his last follow-up he could walk and stand with no support. BMMI is a rare stroke subtype, usually presenting with sudden onset of tetraparesis/tetraplegia, loss of deep sensation, hypoglossal palsy, and bulbar dysfunction, with or without respiratory failure [6]. According to reported studies almost one-fourth of patients with BMMI develop respiratory failure [7]. Typically, the patient becomes acutely dyspneic, tachypneic, and hypoxic within minutes. As we reported the neurological status of our patient gradually improved, but weaning from the ventilator was unsuccessful because he developed pulmonary edema which complicated and therefore prolonged treatment I. Antoncic S. Dunatov M. Sosic (&) R. Antulov M. Bralic Intensive Care Unit, Department of Neurology, Clinical Hospital Center Rijeka, Cambierieva 17/8, 51000 Rijeka, Croatia e-mail: matija.sosic@yahoo.co.uk

Spontaneous recanalization of internal carotid artery occlusion

ZusammenfassungWir stellen einen Fall mit spontaner Rekanalisierung eines Carotis interna Verschlusses vor, der bei einem 51-jährigen männlichem Patienten beobachtet wurde. Der Verschluss der rechten Aerteria carotis interna war asymptomatisch und ein Zufallsbefund im Rahmen der bildgebenden Untersuchung der Arteria carotis der Gegenseite. Die anschließend durchgeführte neuroradiologische Untersuchung ergab eine flammenartige Okklusion, die den Verdacht einer Dissektion der Arterie nahelegte. Die 1 und 5 Monate später durchgeführte Doppler-Ultraschall-Untersuchungen zeigten eine offene rechte Arteria Carotis mit normalem Fluss.SummaryWe present a case of spontaneous recanalization of the internal carotid artery (ICA) that occurred in a 51-year-old male patient. The occlusion of the right ICA was asymptomatic and was detected incidentally during imaging of the opposite carotid artery. The patient underwent neuroradiologic analysis and a tapered, flame-like occlusion suggestive of the right ICA dissection was detected. One month later, a carotid Doppler ultrasound demonstrated patent right carotid artery with normal spectral flow. Five-month follow-up showed that the ICA remained patent.