The blood–brain barrier (BBB) is a dynamic interface responsible for maintaining the central nervous system homeostasis. Its unique characteristics allow protecting the brain from unwanted compounds, but its impairment is involved in a vast number of pathological conditions. Disruption of the BBB and increase in its permeability are key in the development of several neurological diseases and have been extensively studied in stroke. Ischemic stroke is the most prevalent type of stroke and is characterized by a myriad of pathological events triggered by an arterial occlusion that can eventually lead to fatal outcomes such as hemorrhagic transformation (HT). BBB permeability seems to follow a multiphasic pattern throughout the different stroke stages that have been associated with distinct biological substrates. In the hyperacute stage, sudden hypoxia damages the BBB, leading to cytotoxic edema and increased permeability; in the acute stage, the neuroinflammatory response aggravates the BBB injury, leading to higher permeability and a consequent risk of HT that can be motivated by reperfusion therapy; in the subacute stage (1–3 weeks), repair mechanisms take place, especially neoangiogenesis. Immature vessels show leaky BBB, but this permeability has been associated with improved clinical recovery. In the chronic stage (>6 weeks), an increase of BBB restoration factors leads the barrier to start decreasing its permeability. Nonetheless, permeability will persist to some degree several weeks after injury. Understanding the mechanisms behind BBB dysregulation and HT pathophysiology could potentially help guide acute stroke care decisions and the development of new therapeutic targets; however, effective translation into clinical practice is still lacking. In this review, we will address the different pathological and physiological repair mechanisms involved in BBB permeability through the different stages of ischemic stroke and their role in the development of HT and stroke recovery.

The mechanisms whereby Campylobacter jejuni translocates across the host intestinal epithelium are not yet understood and the transepithelial route remains undefined. During C. jejuni translocation, the transmonolayer electrical resistance (TER) across polarised monolayers of Caco‐2 cells is not affected and the penetration of [14C]inulin across the monolayers does not increase. Over 24 h, however, bacteria damage the monolayer integrity, causing a decrease in the TER. These results support C. jejuni translocation through the cytoplasm of invaded cells (transcellular) rather than via intercellular spaces (paracellular).

Campylobacter jejuni colonizes the intestines of domestic and wild animals and is a common cause of human diarrheal disease. We identified a two-component regulatory system, designated the RacR-RacS (reduced ability to colonize) system, that is involved in a temperature-dependent signalling pathway. A mutation of the response regulator gene racR reduced the organism’s ability to colonize the chicken intestinal tract and resulted in temperature-dependent changes in its protein profile and growth characteristics.

The mechanisms whereby Campylobacter jejuni translocates across the host intestinal epithelium are not yet understood and the transepithelial route remains undefined. During C. jejuni translocation, the transmonolayer electrical resistance (TER) across polarised monolayers of Caco-2 cells is not affected and the penetration of [(14)C]inulin across the monolayers does not increase. Over 24 h, however, bacteria damage the monolayer integrity, causing a decrease in the TER. These results support C. jejuni translocation through the cytoplasm of invaded cells (transcellular) rather than via intercellular spaces (paracellular).

Ocular neuromyotonia is a rare, albeit treatable, ocular motor disorder, characterised by recurrent brief episodes of diplopia due to tonic extraocular muscle contraction. Ephaptic transmission in a chronically damaged ocular motor nerve is the possible underlying mechanism. It usually improves with carbamazepine. A 53-year-old woman presented with a 4-month history of recurrent episodes of binocular vertical diplopia (up to 40/day), either spontaneously or after sustained downward gaze. Between episodes she had a mild left fourth nerve palsy. Sustained downward gaze consistently triggered downward left eye tonic deviation, lasting around 1 min. MR scan of the brain was normal. She improved on starting carbamazepine but developed a rash that necessitated stopping the drug. Switching to lacosamide controlled her symptoms.

A 28-year-old man had spasmodic dysphonia due to focal oromandibular-laryngeal dystonia from the age of 6, evolving rostrocaudally into a particular gait dystonia resembling Charlie Chaplin's Charlot gait (video 1). Recently he developed a progressive worsening of bulbar symptoms and a severe dysarthrophonia. No pyramidal or parkinsonism signs were observed. No intellectual dysfunction was noted. Head MRI was normal. Secondary causes of dystonia were excluded. Dystonia next-generation sequencing panel (58 genes) was negative. The sequencing of KMT2B identified a heterozygous de novo variant c5198-4_5206del(p?)-intron24/exon25, classified as pathogenic. This case expands DYT-KMT2B's clinical phenotype due to early oromandibular-laryngeal involvement and atypical gait dystonia. 1,2 Study fundingNo targeted funding reported.

Ochrobactrum anthropi is a Gram-negative bacillus widely distributed in nature. It is a low virulence and low pathogenic microorganism and human infection by this agent is considered rare. This microorganism can cause bacteremia and in some cases can lead to osteomyelitis and endocarditis. Included in Brucellaceae family, this bacterium is phenotypically and genetically closely related to the Brucella genus and may be misidentified by rapid identification systems. The authors describe a patient admitted to the Infectious Diseases Department with vertebral osteomyelitis initially identified as Ochrobactrum anthropi. Despite appropriate antimicrobial therapy, the blood cultures remained positive and there were no signs of clinical improvement. This raised suspicion of a possible misidentification. It was decided to initiate antimicrobial therapy to include the Brucella genus, with slow but progressive clinical improvement. Samples were sent to Instituto Nacional de Saúde Doutor Ricardo Jorge (INSA) for genotyping, confirming the initial suspicion of misidentification and identifying Brucella melitensis as the causal agent. Timely diagnosis of brucellosis is essential for the correct management and prevention of its consequences for the patient and for safe handling of the laboratory samples, preventing laboratory-acquired infection

A growing amount of evidence indicates that 22q11.2 deletion syndrome (22q11.2DS) increases the risk of early-onset Parkinson's disease (EOPD). Here, we describe a 36-year-old patient with EOPD. The patient presented with 22q11.2DS features, including associated cognitive disabilities, hypocalcaemia and facial dysmorphia that led us to screen for and confirm this deletion. In addition, hypocalcaemia and vitamin D deficiency were the main factors responsible for severe, painful muscle spasms that were non-levodopa (L-Dopa) responsive and remitted after calcium and vitamin D replacement therapy. Many patients with this deletion remain undiagnosed until adulthood due to the absence of 'major' phenotypic hallmarks, which usually present during early childhood. Later onset problems involving various medical subspecialties are increasingly recognised as important components of 22q11.2DS. Therefore, the multisystem nature and associated burden of morbidities demand a high degree of suspicion for this entity from all clinicians regardless of their medical subspecialty.