P399 SVILUPPO DI SINDROME DA IMMUNODEFICIENZA ACQUISITA DOPO SOMMINISTRAZIONE DI VASCCINO ANTI–SARAS–COV2

Il SARS–CoV2 è trasmesso tra gli umani attraverso particelle respiratorie e l’infezione può determinare un largo spettro di manifestazioni cliniche. Precedenti studi hanno dimostrato il ruolo centrale dell’immunità cellulo–mediata nel limitare la gravità delle infezioni da virus respiratori. I linfociti T–helper CD4+ sono coinvolti in funzioni di coordinazione e regolazione dell’immunità anti–virale: determinano lo sviluppo di anticorpi neutralizzanti ad alta affinità e la differenziazione dei centri germinali a cellule B in cellule della memoria secernenti anticorpi con lunga vita. Nessun dubbio sul ruolo cruciale della risposta a cellule T durante l’infezione da SARS–CoV2 o dopo la vaccinazione. Descriviamo il caso di un paziente di 39 anni, vaccinato con ChAdOx1–S. Dopo due settimane il paziente accusava dispnea e febbricola. Il test molecolare per SARS–CoV2 era negativo; agli esami ematici la PCR era aumentata. La TC del torace escludeva embolia polmonare e rivelava pattern a vetro smerigliato bilaterale, come da flogisi. All‘ecocardiogramma i parametri erano nella norma. L’ECG mostrava tachicardia sinusale. Il paziente veniva dimesso dal PS con terapia cortisonica. Una settimana dopo i sintomi peggiooravano. Una nuova TC torace mostrava difetti di opacizzazione di rami secondari dell’arteria polmonare ed aspetto bilaterale a vetro smerigliato. Si iniziava terapia con EBPM ed antibiotici a largo spettro. Il test molecolare e la sierologia per SARS–CoV2 erano negativi. Negativi i test per Mycoplasma, Chlamydia, Legionella e CMV DNA. L’emocromo mostrava ridotti linfociti (6,8%) con neutrofilia relativa (90,4%), ma normale valore dei bianchi. La TC–HR mostrava aspetto “crazy paving” bilaterale suggestivo per infezione virale o micotica (pattern come da infezione da Pneumocystis Jiroveci). Il test per HIV aveva esito positivo; alla tipizzazione linfocitaria ridotti i livelli di linfociti T–Helper (CD3+/CD4+) e rapporto CD3+/CD4+ 0%. Per il rapido deterioramento del quadro clinico il paziente veniva trasferito in terapia intensiva. Dopo 30 giorni dalla diagnosi di AIDS il paziente giungeva ad exitus. Il ruolo dei linfociti T nello sviluppo di anticorpi neutralizzanti e di cellule della memoria durante l’infezione da SARS–CoV2 è la chiave nella strategia di vaccinazione per ridurre il dilagare della pandemia, tuttavia nel nostro paziente questo meccanismo non ha funzionato rivelando il deficit del suo sistema immunitario da una latente infezione da HIV.

P96 ACUTE CORONARY SYNDROME AND CORONARY ARTERY KINK

Coronary artery kink is a variant of anomalous coronary artery, not related to vessel disease. Often it is associated with coronary artery tortuosity (CAT) and fibromuscular dysplasia. The pathogenesis and clinical implications are not fully understood. Kinks are hypothesized to cause coronary blood flow alterations that can results in ischemia and even in acute coronary syndrome. It is speculated that coronary artery kinks are most often caused by guide wire straightening and seen after wiring the artery, but that is not always the case. We describe the case of a 55 years old woman, with familiar history of CAD. In 2019 she had percutaneous Patent Foramen Ovale closure intervention. She presented to the Emergency Department complaining chest pain radiating into the neck. The ECG was normal, but Troponin I levels were mildly elevated (2,1 ng/ml) and ipokinesia of basal and mid segment of the anterior intraventricular spetum was found at the ecoscopy. The patient was admitted to Cardiology department with diagnosis of unstable angina and urgent coronary angiography was performed. At a first glance the coronary arteries did not exhibit significant arteriosclerotic or thrombotic changes. However, upon a closer review, a focal kink of the mid left descending coronary artery was found. This coronary kink folded the LAD during systole causing a transient stenosis that resolved during diastole. Management of coronary kinks is controversial. In the past, literature suggested treatment with coronary stenting as one of the management options. However there are reported cases of adverse outcomes, such as shifting of kink proximally, requiring an additional stenting. We decided to treat patient with medical approach: beta–blockers at the tolerated doses was initiated, in addition to ACE–Inibithor, Aspirin and statin. Stenting of the coronary artery was not a choice, due to the possibility of shifting (as described in literature) and stent fracture. At a one month follow up the patient presented asymptomatic for angina, palpitation or dyspnea. Even if rarely coronary artery kink is a potential cause of myocardial ischemia and its treatment is often challenging to improve patient quality of life and to prevent adverse cardiac event.

P335 AORTIC VALVE INFECTIVE ENDOCARDITIS COMPLICATED BY SUPERIOR MESENTERIC ARTERY ACUTE TROMBOSIS

The infective endocarditis (IE) has a significant impact on mortality rate in the first year after diagnosis, despite the improvements in early diagnosis and therapy. Embolic complications cause worsening of patient’s prognosis and they occur in the 20–50% of cases, with a risk of new embolic events after the initiation of antibiotic therapy rated between 6 and 12%. Echocardiographic characterization of vegetation has an important role in the definition of the embolization risk, it is documented that vegetation with dimension more than 10 mm are at higher risk. Several characteristic of the patient (diabetes, previous embolization, atrial fibrillation) determine the increase of the embolization risk, as well as the initiation of antibiotic therapy. We describe the case of a 64 y.o. man with chronic coronary syndrome (previous PCI) and previous Bentall–De Bono intervention for ascending aorta aneurysm. Patient was under anticoagulant therapy with DOAC due to atrial fibrillation. He was admitted to the emergency department for intermittent fever during the last three months, dyspnea and fatigue. Blood test showed neutrophilic leukocytosis and increased value of inflammatory markers. Transthoracic echography revealed an hyperechoic image on the ventricular side of the aortic prosthesis. The diagnosis of infective endocarditis was confirmed with transesophageal echocardiography, and empiric antibiotic therapy was initiated. Cardiac surgeon suggested follow up and new evaluation after three weeks of therapy. Clinical course was complicated by acute abdomen. The CT exam revealed dilation of a distal tract of superior mesenteric artery (maximum axial diameter was 10 mm) associated with distal thrombosis extended for 6 mm. The transthoracic echocardiogram showed absence of the vegetation on aortic prosthesis previous documented. Therapy with intravenous infusion of unfractionated heparin was administrated for three weeks, but the control TC showed persistence of the thrombotic occlusion of superior mesenteric artery so the case was discussed with Vascular Surgery team. They decided to treat patient with embolization and aneurysmectomy surgery (cultures were negative). This clinical case demonstrates that embolic complication of infective endocarditis, even on proper antbiotic therapy and close monitorization, are unpredictable and can cause the worsening of patient’s clinical course.

P167 ECG ABNORMALITIES AND DOUBLE CORONARY FISTULA

Coronary artery fistula (CAF) is defined as anomalous communication between coronary arteries and cardiac chamber or a major thoracic vessel. CAF are a rare coronary anomaly, mostly congenital, first described by Krause in 1856. In literature the incidence in general population is approximately 0,002%. Detection of CAF during coronary angiography is usually accidental. In 50% of cases CAF originate from right coronary artery, in 30% they originate from LAD, while in the rest of the percentage CAF originate from left circumflex artery. CAF drain into low–pressure chamber (right ventricle or right atrium, superior Vena Cava or pulmonary artery). We can distinguish CAF into little or medium sized, usually with silent clinical course, and large sized CAF, with variable clinical signs, depending on the extent of the shunt and on the hemodynamic overload of the receiving chamber. We describe the case of a 57 y.o woman with hypertension, admitted for femur fracture. ECG showed bifasic T waves in the anterior leads, already described in a previous ECG. Normal systolic function and no valvular defect were found on the echocardiogram. Patient was asymptomatic. Coronary angiography documented normal coronary arteries, with a double coronary fistula: the first from a septal branch of posterior descending and the second one from distal branches of the first diagonal. Even if CAF have often a favorable clinical course with no relevant consequences for the patient, it’s crucial to obtain more information about their functional implication and their anatomic connections. Indeed, rare cases of sudden cardiac death have been described in patients with CAF involved in myocardial ischemia based on the theft syndrome mechanism. Echocardiographic evaluation of the patient to detect associated congenital abnormalities, pressure overload of the receiving chambers and the extent of the shunt on the coronary angiography are crucial for the proper management of CAF. In the case described above we decided to optimize therapy adding beta–blocker (to reduce the overload caused by the two coronary fistula).

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The forkhead transcription factor UNC-130 is required for the graded spatial expression of the UNC-129 TGF-beta guidance factor in C. elegans

Secreted proteins required for cellular movements along the circumference of the body wall in Caenorhabditis elegans include UNC-6/netrin and the novel TGF-beta UNC-129. Expression of these proteins is graded along the dorsoventral (D/V) axis, providing polarity information to guide migrations. Here we show that the graded expression of UNC-129 in dorsal but not ventral body muscles depends on unc-130, which encodes a Forkhead transcription factor. The phenotype of unc-130 mutants closely mimics the reported effects of ectopically expressing unc-129 in both dorsal and ventral body muscles (). This fits our present finding that unc-130 cell autonomously represses unc-129 expression in the ventral body muscles. Thus the cell-specific effects of unc-130 on ventral, but not dorsal, body muscle expression of unc-129 accounts for the D/V polarity information required for UNC-129-mediated guidance. Genetic interactions between unc-130 and other guidance genes show that several molecular pathways function in parallel to guide the ventral to dorsal migration of distal tip cells (DTCs) and axonal growth cones in C. elegans. Genetic interactions confirm that UNC-129 does not require the only known type II TGF-beta receptor in C. elegans (DAF-4) for its guidance functions. Also, unc-130 is partially required for male tail morphogenesis and for embryogenesis.

ATP-Induced Ca(2+) release in cochlear outer hair cells: localization of an inositol triphosphate-gated Ca(2+) store to the base of the sensory hair bundle

We used a high-performance fluorescence imaging system to visualize rapid changes in intracellular free Ca(2+) concentration ([Ca(2+)](i)) evoked by focal applications of extracellular ATP to the hair bundle of outer hair cells (OHCs): the sensory-motor receptors of the cochlea. Simultaneous recordings of the whole-cell current and Calcium Green-1 fluorescence showed a two-component increase in [Ca(2+)](i). After an initial entry of Ca(2+) through the apical membrane, a second and larger, inositol triphosphate (InsP(3))-gated, [Ca(2+)](i) surge occurred at the base of the hair bundle. Electron microscopy of this intracellular Ca(2+) release site showed that it coincides with the localization of a unique system of endoplasmic reticulum (ER) membranes and mitochondria known as Hensen's body. Using confocal immunofluorescence microscopy, we showed that InsP(3) receptors share this location. Consistent with a Ca(2+)-mobilizing second messenger system linked to ATP-P2 receptors, we also determined that an isoform of G-proteins is present in the stereocilia. Voltage-driven cell shape changes and nonlinear capacitance were monitored before and after ATP application, showing that the ATP-evoked [Ca(2+)](i) rise did not interfere with the OHC electromotility mechanism. This second messenger signaling mechanism bypasses the Ca(2+)-clearance power of the stereocilia and transiently elevates [Ca(2+)](i) at the base of the hair bundle, where it can potentially modulate the action of unconventional myosin isozymes involved in maintaining the hair bundle integrity and potentially influence mechanotransduction.

An optical recording system based on a fast CCD sensor for biological imaging

This paper presents technical details, hardware and software of a complete imaging system which uses a fast CCD sensor and a 41 Msample/s A/D converter to acquire full-frame 12 bit/pixel digitized images with a time resolution of 1.25 ms/image. This apparatus permits to resolve intracellular Ca2+ gradients in individual cells as well as the spatio-temporal pattern of neural activity of cell assemblies in neural tissue.

Pioneer axon guidance by UNC-129, a C. elegans TGF-beta

The unc-129 gene, like the unc-6 netrin gene, is required to guide pioneer motoraxons along the dorsoventral axis of Caenorhabditis elegans. unc-129 encodes a member of the transforming growth factor-beta (TGF-beta) superfamily of secreted signaling molecules and is expressed in dorsal, but not ventral, rows of body wall muscles. Ectopic expression of UNC-129 from ventral body wall muscle disrupts growth cone and cell migrations that normally occur along the dorsoventral axis. Thus, UNC-129 mediates expression of dorsoventral polarity information required for axon guidance and guided cell migrations in C. elegans.

Suppressors of ectopic UNC-5 growth cone steering identify eight genes involved in axon guidance in Caenorhabditis elegans

The UNC-5 guidance receptor, in response to the UNC-6/netrin path cue, orients growing axons in a dorsal direction along the epidermis of Caenorhabditis elegans. When ectopically expressed in the touch neurons, which normally extend ventrally or longitudinally, UNC-5 is able to reorient their axons toward the dorsal side in an UNC-6-dependent manner. This forms the basis of a genetic screen to identify other mutations that, like unc-6 mutations, suppress unc-5-induced growth cone guidance. These mutations may identify new components required for pioneer axon guidance by unc-5. In this paper, we describe eight genes that are required for ectopic unc-5-induced growth cone steering. Mutations in four of these identify the previously known axon guidance genes unc-6, unc-40, unc-34, and unc-44 and mutations in four others identify the novel genes unc-129, seu-1, seu-2, and seu-3. Several of these mutations cause axon guidance defects similar to those found in unc-5 mutants. We propose that some or all of these genes may function in a developmentally important unc-5 signaling pathway.

Ikirara, a novel transposon family from the malaria vector mosquito, Anopheles gambiae

Members of a novel transposon family, Ikirara, were found in the genome of the malaria vector Anopheles gambiae. They are most abundant in A. gambiae sensu stricto, but related sequences were found in all four other tested members of this species complex. No relatives were found in A. funestus or A. stephensi. Ikirara1, the first isolated family member, was found between two of the tandem Vitellogenin (Vg) genes. Because it was found at this location in G3 and only one of nine other A. gambiae s.s. strains examined, and because its 216 bp inverted terminal repeats are 100% identical, transposition to this locus may have been recent. Ikirara1 inverted repeat terminal sequences are similar to those of DNA to DNA transposons of the mariner/Tc1 and hAT superfamilies. Also similar to mariner/Tc1 elements, insertion of Ikirara1 apparently created a duplication of the dinucleotide TA at the target site.