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Kaon physics is at a turning point – while the rare-kaon experiments NA62 and KOTO are in full swing, the end of their lifetime is approaching and the future experimental landscape needs to be defined. With HIKE, KOTO-II and LHCb-Phase-II on the table and under scrutiny, it is a very good moment in time to take stock and contemplate about the opportunities these experiments and theoretical developments provide for particle physics in the coming decade and beyond. This paper provides a compact summary of talks and discussions from the Kaons@CERN 2023 workshop, held in September 2023 at CERN. [ABSTRACT FROM AUTHOR]

Accurate intraoperative tumour margin assessment is a major challenge in neurooncology, where sparse tumours beyond the bulk tumour are left undetected under conventional resection. Non-linear optical imaging can diagnose tissue at the sub-micron level and provide functional label-free histopathology in vivo. For this reason, a non-linear endomicroscope is being developed to characterize brain tissue intraoperatively based on multiple endogenous optical contrasts such as spectrally- and temporally-resolved fluorescence. To produce highly sensitive optical signatures that are specific to a given tissue type, short femtosecond pulsed lasers are required for efficient two-photon excitation. Yet, the potential of causing bio-damage has not been studied on neuronal tissue. Therefore, as a prerequisite to clinically testing the non-linear endomicroscope in vivo, the effect of short laser pulse durations (40–340 fs) on ex vivo brain tissue was investigated by monitoring the intensity, the spectral, and the lifetime properties of endogenous fluorophores under 800 and 890 nm two-photon excitation using a bi-modal non-linear endoscope. These properties were also validated by imaging samples on a benchtop multiphoton microscope. Our results show that under a constant mean laser power, excitation pulses as short as 40 fs do not negatively alter the biochemical/ biophysical properties of tissue even for prolonged irradiation. [ABSTRACT FROM AUTHOR]

Autofluorescence analysis allows new insights on human tissue without any dye in a non-invasive way and therefore seems well suited to study historical samples. An optical set-up recorded emitted autofluorescence in 1/spectral and 2/lifetime domains from different samples' regions of interest. The studied samples were a mummified right hand, bog body (Tollund Man) feet and a male Caucasian hand (control sample). Spectral analysis revealed that mummified hand exhibited broad autofluorescence spectra, whereas Tollund Man's feet exhibited a weak single peak with 405-nm excitation wavelength. Control sample spectra are weaker than that of the mummified hand but higher than the Tollund Man's feet. Lifetime measurements indicated the presence of classical endogenous fluorophores on the mummified right hand. The Tollund Man's feet exhibited two patterns of lifetime measurements: healthy zone exhibited lifetime values at four emission wavelengths but skin lesions at only two wavelengths. This first report of mummified samples' autofluorescence analysis suggests the potential of optical analysis for archeologic research. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

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Arterial vasospasm has rarely been reported following temporal lobectomy for intractable epilepsy. A 31-year-old patient presented with a global aphasia 2 days after a left dominant anteromesial temporal lobectomy for intractable epilepsy. Magnetic resonance imaging on 5th post-operative day revealed severe narrowing of M1 segment of the left middle cerebral artery (MCA) and Transcranial Doppler (TCD) ultrasonography an increased velocity of the MCA that suggested a severe vasospasm. The patient received continuous intravenous hyperhydratation and nimodipine; aphasia improved within 24 h and resolved completely within 6 weeks, associated with velocity reduction on control TCD. Transient vasospasm is a likely underestimated cause of focal deficit following temporomesial resection that deserves appropriate treatment. [ABSTRACT FROM AUTHOR]

Background: Adrenalectomy for pheochromocytoma is a life-threatening procedure. Few echocardiographic assessments have been reported in patients undergoing adrenalectomy for pheochromocytoma. Methods: Sixty-three consecutive patients undergoing adrenalectomy for pheochromocytoma underwent routine preoperative M-mode and two-dimensional echocardiography, and Doppler examination. Abnormal echocardiographic findings were defined as left ventricular dilatation or dysfunction (left ventricular percentage fractional shortening < 30%), and/or left ventricular wall motion abnormalities, and/or left ventricular hypertrophy (left ventricular mass index > 110 g m(-2) in women and >134 g m(-2) in men) and/or valvular abnormalities. Physical characteristics, daily urinary metanephrine and normetanephrine excretions, preoperative functional limitation, pre-existing congestive heart failure, type and duration of surgery, and haemodynamic instability in the intra and postoperative periods were compared in patients with normal and abnormal echocardiographic findings. Results: Twenty-four out of 63 patients were found to have abnormal preoperative echocardiography. There was no difference between patients with normal and abnormal preoperative echocardiography as regards to the investigated criteria, except for pre-existing self-reported functional limitation and chest pain suggesting coronary artery disease. Conclusions: The relevance of routine preoperative echocardiographic examination in patients scheduled for adrenalectomy for pheochromocytoma, who have no cardiac symptoms or clinical evidence of cardiac involvement, is questionable. [ABSTRACT FROM AUTHOR]

The authors present their first experience with laser interstitial thermotherapy, (ITT). Four patients with deep-seated non-infiltrative benign tumours (three astrocytomas, one oligodendrocytoma) underwent ITT. Previously, a stereotactic procedure had been performed to determine the exact location of the tumour, its spatial configuration and its histological diagnosis. The MRI controls confirmed the efficacy of hyperthermia on the tumour tissues. The authors discuss the possible ITT mechanisms. The indications of such laser ITT in neurosurgery should be enlarged to malignant tumours (gliomas, metastases) and to certain hypophyseal adenomas. [ABSTRACT FROM AUTHOR]

The early 1970s saw the birth of microscopic neurosurgery and the late 1970s the birth of laser neurosurgery. For more than 10 years now, laser radiations have been used during neurosurgical procedures: mostly for tumoral removal concerning essentially benign lesions. The reference laser has been and still is the CO laser, which has a limited penetration into CNS tissues. Until recently the Nd-YAG laser was used with its normal spectral transition, 1.064 μm. Because of its important diffusion in the CNS, it cannot be widely used except for shrinking large vascularized tumours such as meningiomas. The technological evolution has brought the laser specialists-physicists, medical doctors and surgeons-new concepts and new wavelengths which will progressively broaden laser applications and surgical procedures towards greater effectiveness, security and simplification. Holmium-YAG (2.1 μm), Erbium-YAG (2.9 μm) or long Nd-YAG wavelengths (1.44 or 1.32 μm) have been studied by different teams. The 1.32 μm Nd-YAG transition has been clinically used for about 2 years by a few neurosurgical teams (Beck in Munich, Roux in Paris, and more recently Lombard and Fasano in Torino, Ascher in Gratz). Laser radiations can be useful essentially during the removal of benign tumours, mostly if they are well vascularized and placed near functional structures such as the brain stem, the cranial nerves, the spinal cord: the CO laser is most efficient for vaporization; 1.06 Nd-YAG is effective for coagulation; 1.32 Nd-YAG provides very satisfactory photoevaporation effects if used with a superpulsed emission, and/or with a focusing handpiece, it also has good haemostatic properties with a c.w. output. The development of new optic fibre conducted wavelengths appears to be a possible answer to new requisites which should lead to the development of endoscopic neurosurgery (intraventricular tumours, discal herniations) and sterotaxic laser surgery (deep-seated intra-cerebral lesions). [ABSTRACT FROM AUTHOR]

During the past 10 years, considerable attention has been devoted to cognitive impairment in multiple sclerosis. Occasionally this impairment may be so severe that multiple sclerosis presents as a dementia associated with only minor neurological signs and symptoms. The cases of two women affected by multiple sclerosis who presented with a pure dementia are reported. In the first patient, a progressive apragmatic behavioural disturbance with reduced short term memory and learning abilities were the main clinical features. Neuropathological examination of the brain disclosed numerous plaques in the periventricular white matter, with severe atrophy of the corpus callosum. Plaques were also seen in the white matter of both hippocampus and in the columns of the fornix. The impairment of short term memory could be linked to these lesions. Behavioural changes were probably related to the bilateral lesions of the long associative bundles that disconnected the frontal lobes from other parts of the cerebral hemispheres. In the second patient, visual hallucinations were associated with cognitive dysfunction. MRI showed large plaques in the white matter of both left frontal and temporal lobes. Smaller plaques were also present in the periventricular white matter of the occipital lobes, the nature of which were confirmed by a stereotactic biopsy. [ABSTRACT FROM AUTHOR]

Two cases of meningeal sarcoidosis with unusual and misleading presentations are reported. In the first case, CT scan, angiographic, and MRI findings were indistinguishable from those of meningioma. CSF pleiocytosis may help in diagnosing sarcoid pseudo-meningioma. The second patient had transient focal deficits and pachymeningitis of the convexity. The transient deficits were probably of epileptic origin based on their response to antiepileptic treatment. The diagnosis of neurosarcoidosis was made only after meningeal biopsy, despite thorough investigations. [ABSTRACT FROM AUTHOR]

We report six cases of segmental agenesis of the internal carotid a. discovered in adult patients: one case of cervical segmental agenesis (no. 1), one case of cervical and petrosal segmental agenesis (no. 2), two cases of vertical cavernous segmental agenesis (nos. 3 and 4) and two cases of distal segmental agenesis, one unilateral (no. 5) and the other bilateral (no. 6). The collateral pathways observed were: the ascending pharyngeal a. which constitutes an “intratympanic course” of the internal carotid a. (no. 1), an intercarotid anastomosis (no. 2), an arterial network at the base of the skull, the so-called “rete mirabile” (nos. 3 and 4) and the posterior communicating a. (nos. 5 and 6). Recognition of these rare dysgeneses relies upon the following radio-anatomic characteristics: reduced caliber of the a., inconsistent sparing of the carotid body, reduced diameter or even absence of the carotid canal and above all, the presence of collateral pathways. The collateral pathways allow an understanding of the segmental nature of carotid a. development and a distinction between congenital and acquired stenoses. [ABSTRACT FROM AUTHOR]

From initial experiments of ruby, argon and CO lasers on the nervous system so far, dramatic progress was made in delivery systems technology as well as in knowledge of laser-tissue interaction effects and hazards through various animal experiments and clinical experience. Most surgical effects of laser light on neural tissue and the central nervous system (CNS) are thermal lesions. Haemostasis, cutting and vaporization depend on laser emission parameters - wavelength, fluence and mode - and on the exposed tissues optical and thermal properties - water and haemoglobin content, thermal conductivity and specific heat. CO and Nd-YAG lasers have today a large place in the neurosurgical armamentarium, while new laser sources such as high power diode lasers will have one in the near future. Current applications of these lasers derive from their respective characteristics, and include CNS tumour and vascular malformation surgery, and stereotactic neurosurgery. Intracranial, spinal cord and intra-orbital meningiomas are the best lesions for laser use for haemostasis, dissection and tissue vaporization. Resection of acoustic neuromas, pituitary tumours, spinal cord neuromas, intracerebral gliomas and metastases may also benefit from lasers as accurate, haemostatic, non-contact instruments which reduce surgical trauma to the brain and eloquent structures such as brain stem and cranial nerves. Coagulative lasers (1.06 μm and 1.32 μm Nd-YAG, argon, or diode laser) will find an application for arteriovenous malformations and cavernomas. Any fiberoptic-guided laser will find a use during stereotactic neurosurgical procedures, including image-guided resection of tumours and vascular malformations and endoscopie tumour resection and cysts or entry into a ventricle. Besides these routine applications of lasers, laser interstitial thermotherapy (LITT) and photodynamic therapy (PDT) of brain tumours are still in the experimental stage. The choice of a laser in a neurosurgical operating room implies an evaluation of the laser use (applications, frequency), of the available budget and costs-including purchase, maintenance and staff training-, and material that will be necessary: unit, peripherals, safety devices and measures, training programme. Future applications of lasers in neurosurgery will come from technological advances and refined experimental applications. The availability of new wavelength, tunable, small sized and 'smart' laser units, will enlarge the thermal and non-thermal interactions between laser energy and neural tissue leading to new surgical applications. Tissue photo-ablation, photohynamic therapy using second generation of photosensitizers, updated thermotherapy protocols, are current trends for further use of lasers in neurosurgery. [ABSTRACT FROM AUTHOR]

The authors, since 1985, have used 587 Madreporic Coral grafts as bone substitute in a total of 183 patients, among them in 80 cases for repair of cranial base bone defects. They report their long-term results. Partial resorption to about 40% of the initial volume occurred in almost all cases within 8 to 10 months, with complete resorption after about one year. 20% of the coral blocks moved spontaneously or split into pieces, but could easily be withdrawn rhinoscopically through the nostrils. No CSF leakage was noticed afterwards. The local infection rate was only 4%, always close to the basal coral graft. This is lower than the infection rate after using autologous bone harvested from the inner table of the bone flap (20%). Infections were cured by removal of the coral graft. Despite the mentioned draw backs, Madreporic Coral graft implants can be recommended as bone substitute in cranial base surgery: [ABSTRACT FROM AUTHOR]

The authors present their clinical experience with 1.32 μm NdYAG Laser. After a series of experimental studies which demonstrated the adaptability of such a wavelength to central nervous surgery, they used such a Laser during current neurosurgical procedures. The MC 2100 unit combines two wavelengths 1.32 μm and 1.06 μm, and two emission modes: continuous wave (c.w.) and pulsed. This Laser has been used during 70 procedures: 54 supra-tentorial, 8 infra-tentorial, 5 intra-spinal, 3 intra-orbital. 600 μm and 400 μm fibers were preferred in most cases, either with a telescopic light handpiece or-less often-with a focussing handpiece. The quality of vaporization-close to that of CO Laser-and of haemostasis -close to that of 1.06 μm Nd-YAG Laser-makes this 1.32 μm wavelength very suitable for neurosurgery. The manoeuverability due to the optic fibers is most interesting. Furthermore, such a Laser should have in the near future large applications in stereotactic and/ or endoscopic neurosurgery. [ABSTRACT FROM AUTHOR]

Background In the present study, the hypothesis was tested that cell adhesion molecules are expressed in failing human hearts and that a chronic inflammatory process contributes to chronic degeneration known to occur in cardiac incompetence. The cell adhesion molecules: ICAM-1, VCAM-1, PECAM-1, and E-selectin were studied, in addition to cellular markers of inflammation. Methods and results Tissue was obtained at transplantation from patients with either myocarditis, chronic ischaemic heart disease, or dilated cardiomyopathy. Controls were taken from patients with normal ventricles. Cell adhesion molecules were qualitatively evaluated and counted using specific antibodies and confocal microscopy. Additionally, semiquantitative evaluation of the presence of the CD3 antigen (T-lymphocytes), CD68 (macrophages), CD11a/CD18 (ICAM-1 receptor) and human tumour necrosis factor-α were used as indicators of chronic inflammation. PECAM-1 stained all endothelial cells but ICAM-1 was only present in 80% of all capillaries in control tissue. The ratio ICAM-1/PECAM-1 was significantly enhanced in all groups of diseased hearts. Myocytes in myocarditic hearts expressed ICAM-ICAM. CD3 positive lymphocytes, CD68 positive macrophages and CD11a/;CD18 positive cells were more abundantly present than in control. Macrophages expressing tumour necrosis factor-α were found in failing myocardium but not in control tissue. Conclusion Independent of the cause of heart failure, chronic low grade inflammation is present in failing human myocardium. This may significantly contribute to the structural deterioration that is the basis of reduced cardiac function in congestive heart failure. [ABSTRACT FROM PUBLISHER]