Percutaneous puncture during PCNL: new perspective for the future with virtual imaging guidance.

CONTEXT: Large and complex renal stones are usually treated with percutaneous nephrolithotomy (PCNL). One of the crucial steps in this procedure is the access to the collecting system with the percutaneous puncture and this maneuver leads to a risk of vascular and neighboring organs' injury. In the last years, the application of virtual image-guided surgery has gained wide diffusion even in this specific field. OBJECTIVES: To provide a short overview of the most recent evidence on current applications of virtual imaging guidance for PCNL. EVIDENCE ACQUISITION: A non-systematic review of the literature was performed. Medline, PubMed, the Cochrane Database and Embase were screened for studies regarding the use virtual imaging guidance for PCNL. EVIDENCE SYNTHESIS: 3D virtual navigation technology for PCNL was first used in urology with the purpose of surgical training and surgical planning; subsequently, the field of surgical navigation with different modalities (from cognitive to augmented reality or mixed reality) had been explored. Finally, anecdotal preliminary experiences explored the potential application of artificial intelligence guidance for percutaneous puncture. CONCLUSION: Nowadays, many experiences proved the potential benefit of virtual guidance for surgical simulation and training. Focusing on surgery, this tool revealed to be useful both for surgical planning, allowed to achieve a better surgical performance, and for surgical navigation by using augmented reality and mixed reality systems aimed to assist the surgeon in real time during the intervention.

Crossed beam studies of elementary reactions of N and C atoms and CN radicals of importance in combustion.

The dynamics of some elementary reactions of N(2D), C(3P,1D) and CN(X2 sigma +) of importance in combustion have been investigated by using the crossed molecular beam scattering method with mass spectrometric detection. The novel capability of producing intense, continuous beams of the radical reagents by a radio-frequency discharge beam source was exploited. From angular and velocity distribution measurements obtained in the laboratory frame, primary reaction products have been identified and their angular and translational energy distributions in the center-of-mass system, as well as branching ratios, have been derived. The dominant N/H exchange channel has been examined in the reaction N(2D) + CH4, which is found to lead to H + CH2NH (methylenimine) and H + CH3N (methylnitrene); no H2 elimination is observed. In the reaction N(2D) + H2O the N/H exchange channel has been found to occur via two competing pathways leading to HNO + H and HON + H, while formation of NO + H2 is negligible. Formation of H + H2CCCH (propargyl) is the dominant pathway, at low collision energy (Ec), of the C(3P) + C2H4 reaction, while at high Ec formation of the less stable C3H3 isomers (cyclopropenyl and/or propyn-1-yl) also occurs; the H2 elimination channel is negligible. The H elimination channel has also been found to be the dominant pathway in the C(3P,1D) + CH3CCH reaction leading to C4H3 isomers and, again, no H2 elimination has been observed to occur. In contrast, both H and H2 elimination, leading in comparable ratio to C3H + H and C3(X1 sigma g+) + H2(X1 sigma g+), respectively, have been observed in the reaction C(3P) + C2H2(X1 sigma g+). The occurrence of the spin-forbidden molecular pathway in this reaction, never detected before, has been rationalized by invoking the occurrence of intersystem crossing between triplet and singlet manifolds of the C3H2 potential energy surfaces. The reaction CN(X2 sigma +) + C2H2 has been found to lead to internally excited HCCCN (cyanoacetylene) + H. For all the reactions the dynamics have been discussed in the light of recent theoretical calculations on the relevant potential energy surfaces. Previous, lower resolution studies on C and CN reactions carried out using pulsed beams are noted. Finally, throughout the paper the relevance of these results to combustion chemistry is considered.

Experiments on the dynamics of molecular processes: a chronicle of fifty years.

This paper reviews the way in which, in the Italy of the years immediately after World War II, interest in the dynamics of molecular processes was awakened. The narrative begins with the work of a small number of chemists and physicists who, in the initial stage, interacted closely. In the course of the years, their interests diverged and younger people joined the newly formed groups. Even now, after half a century, a common approach can still to be seen regarding how to attack problems and perform experiments. Experimental work is discussed, bringing out the common viewpoint of fields as diverse as mass spectrometry, isotope effects, chemical kinetics, molecular beams, molecule-molecule interactions, molecule-ion interactions, molecule-surface interactions, and plasma chemistry.

Crossed-beam studies of reaction dynamics.

This article reviews recent progress in our understanding of gas-phase neutral reaction dynamics as made possible by improvements in the crossed molecular beam scattering technique for measuring reactive differential cross sections. A selection of crossed-beam studies on systems that play a fundamental role in our basic understanding of reaction phenomena are discussed to illustrate the capabilities of the experimental method. The examples include benchmark atom-diatom abstraction and insertion reactions, and four-atom radical reactions for which state-to-state, state-resolved, or state-averaged differential cross sections have recently been measured. The results are discussed in the light of the latest related theoretical developments regarding the treatment of potential energy surfaces and the dynamics of the systems. Recent results on crossed-beam studies of chemically relevant reactions of carbon, nitrogen, and oxygen atoms are also reviewed, and the latest developments in the technique are noted.

Surgery of local recurrence in rectal cancer.

The local recurrence, after radical exeresis of a large intestinal cancer represents until now an extremely interesting question, taking into consideration that it represents the cause of death in 50% of operated patients. Frequency is higher after an exeresis of a rectal cancer, with a range of 2.6-83% in the different case histories, than after a surgical intervention on a colon cancer, whose incidence is lower than 5%. The early diagnosis of rectum cancer recurrence is the first step towards the favourable issue of treatment. Surgical treatment of loco-regional recurrences of rectum cancer can be curative when it is possible to perform a total resection of the recurrences and of the infiltrated structures, without microscopic residuals of disease, or palliative, aiming to reset the intestinal and urinary functions or to reduce pain. At the Department of Surgery of the University of Perugia, from January 1984 to December 1983, 153 patients with rectal cancer-79 males (52%) and 74 females (48%)-were treated. The operations, all involved total removal of the affected segment and were in 88 cases (58%) an anterior resection and in 65 cases (42%) an abdomino-perineal amputation. The analysis was made of 128 patients with a follow-up of at least five years; the local recurrence incidence was 12.5%. The authors adopted a follow-up protocol based on clinical examination, CEA antigen and routine Lab tests, chest X-rays, colonoscopy, abdominal ultrasonography, pelvic CT scan; these procedures are performed starting 3 months after operation.

[Thoracic trauma]. / I traumi del torace.

From January 1989 to December 1992, in the Institute of Clinical Surgery of the University of Perugia, 102 patients were admitted for thoracic trauma. Two patients with an open thoracic trauma, both presenting multiple shot-wounds, underwent an explorative thoracotomy. One of them died on the operating-table from hemorrhage, while the other was saved by a wedge-resection. A 3rd explorative thoracotomy was successfully performed on a patient with internal thoracic trauma and severe hemothorax. Among the 100 patients with an internal thoracic trauma, mortality was 6%, but only one of the 6 deceased, had no lesions other than a fail chest. As a matter of fact 38 patients presented lesions in other parts of the body. Simple and complicated multiple costal fractures, found in 84 cases, were the most frequent lesions observed. Seventeen of the 38 patients with pneumothorax and/or pleural effusion had a chest tube applied. Three patients were operated for a diaphragmatic hernia with a positive outcome. Only 75 patients received medical treatment without surgery. Six of the patients with multiple costal fractures presented flail chest. One of them (mentioned above) died almost immediately after his admission and therefore received no more than the initial medical treatment. Four others, aged over 65, successfully underwent a costal osteosyntesis, while the 6th patient received medical therapy with a positive outcome. In the case of a critical flail chest with severe patho-physiological consequences, if the fractures are in technically favourable sites, the Authors believe it is better to immediately stabilize the thorax, since the operating trauma is minimum and in many cases the patient is already intubated and curarized.

[Primary cancer of the gastric stump. Apropos of 8 cases]. / Cancer primitif du moignon gastrique. A propos de huit observations.

The authors review their experience of 8 cases of primary carcinoma of the gastric stump during the period 1989-1992. During the same period, 164 gastric cancers were treated in the same department. Mean duration between primary gastric resection and diagnosis of gastric stump carcinoma was 30 years (6 to 42 years). All patients underwent a Billroth II primary gastric resection. Only 4 patients underwent radical surgical resection of their gastric stump carcinoma; 2 patients underwent only explorative laparotomy for very advanced and unresectable gastric stump carcinoma; 2 patients were inoperable because of their general status. This series of 8 cases of gastric stump carcinoma emphases the importance of endoscopic investigations during follow-up of patients with gastric resection, in order to diagnose and treat resectable gastric stump carcinoma.

[Diagnostic and therapeutic problems of "second look" in acute intestinal ischemia]. / Problematiche diagnostiche e terapeutiche nel "second look" delle ischemie intestinali acute.

The authors present their diagnostic approach to acute intestinal ischemia. They underline the need for early specific diagnosis because the therapeutic options vary widely in relation to different types of acute intestinal ischemia. Selective arteriography preceded by an aortogram is considered the diagnostic "gold standard". Although at present mesenteric ischemia is a serious, and often lethal, disease, an aggressive therapeutic approach can improve the outcome of this group of patients.

Preoperative evaluation of inferior vena cava involvement secondary to malignant abdominal neoplasms.

The authors report their experience of different imaging techniques (US, CT, MRI, and cavography) used to evaluate inferior vena cava involvement due to abdominal malignant neoplasms. The study is a retrospective analysis of preoperative data on 15 patients of both sexes in comparison with intraoperative and/or pathological findings. All patients underwent ultrasonography, with good results in all the venous segments studied, as for the CT scan; the limitation of both techniques is the unsafe evaluation of venous wall involvement when the neoplastic tissue is confined inside the vessel. The results obtained using MRI seem to be very encouraging, but we only studied three cases with this technique, and so cannot assess the real value of the method. In nine patients we performed inferior cava phlebography: we believe this to be a very reliable exam to demonstrate vessel wall invasion, even if it is a very invasive procedure, its limits being the inability to observe proximal thrombotic extension when the vein is completely obstructed by the tumor. On the basis of their experience the authors suggest a multi-technique imaging diagnostic procedure for preoperative staging with a view to obtaining as much information as possible to correctly program surgical procedure.

[Progressive familial myoclonic epilepsy with bulbo-spinal amyotrophy. Clinical, electrophysiological study, and biopsy of a case]. / Epilessia mioclonica progressiva familiare associata ad amiotrofia bulbo-spinale. Studio clinico, elettrofisiologico e bioptico di un caso.

Two brothers with Progressive myoclonic epilepsy and Juvenile bulbar and spinal atrophy had clinical, neurophysiological study and muscle biopsy. The EEG and polygraphic findings included progressive slowing of the background activity, spontaneous fast generalised spike- and wave discharges and photosensitivity. The EMG revealed pathological spontaneous activity as well as motor unit potentials diminished in number and increased in amplitude and duration; while VDCS and VDCM were normal. Results of muscle biopsy showed no represented "ragged red fibers" with the modified Trichrome stain, while grouped small caliber angular fibers of both histochemical type were visible with the myofibrillar ATPase reaction, but type 2 fibers predominated amongst the atrophic ones. Serum and urine metabolic measurement and lysosomal enzyme activities in leukocytes were all normal. We feel that the reported case might represent a familial syndrome not previously recognized showing non-specific degenerative changes with neuropathological examination. This disorder is similar only to the case reported by Lance J.W. and Ewans W.A. in 1984 "Progressive myoclonic epilepsy, nerve deafness and muscular atrophy".

Ecology of viruses isolated from sand flies in Italy and characterized of a new Phlebovirus (Arabia virus).

A total of 84 virus strains was obtained from 16,374 male and female sand flies (Phlebotomus perniciosus and P. perfiliewi) collected in two localities of Tuscany region in Italy between 1980 and 1985. Thirty-seven (44%) were identified as Toscana virus (family Bunyaviridae, genus Phlebovirus) and 47 (56%) as a new member of the Phlebotomus fever serogroup, Arbia virus. The characteristics of this new serotype are described. The overall virus isolation rate from sand flies was 0.5 per 100 insects processed. Virus isolation rates for both viruses were similar in different years and in the two localities, suggesting that the two virus types were active in the sand fly population simultaneously. Each year, the largest number of isolates were obtained during July, corresponding to the period of maximal sand fly population density. Both viruses were repeatedly isolated from male sand flies, suggesting transovarial transmission in nature. Serologic data showed no evidence of infection among domestic and wild animals. However, a strain of Toscana virus was isolated from the brain of a bat (Pipistrellus kuhli), indicating a possible involvement of this species in the ecology of the virus. Serologic tests did not provide definitive evidence for human infection by Arbia virus.

Autosomal-dominant dystrophy with humeroperoneal weakness and cardiopathy: a genetic variant of Emery-Dreifuss disease?

Two females mother and daughter, were affected by a neuromuscular disorder, characterized by slow progression, humeroperoneal weakness and wasting, limited neck flexion, elbow and ankle joint contractures, cardiopathy and myopathic pattern on EMG. Muscle histology and histochemistry showed type I fiber atrophy and predominance in both. Cardiac abnormalities, in the first case, were suggestive of a hypertrophic cardiomyopathy while in the second hypotension and chronic bradycardia were present. Neurological signs, EMG and morphology seemed to point to a genetic variant of the form of dystrophy named Emery-Dreifuss disease. The mode of transmission and cardiac abnormalities, however, raise the problem of variability even in this well-defined, usually X-linked, disorder.

Sarcoidosis of the peripheral nerve: clinical, electrophysiological and histological study of two cases.

Two cases of sarcoid polyneuropathy were diagnosed by histological examination of the nerve biopsy. The electrophysiological findings in both patients suggested a neuropathy of axonal type, confirmed by a morphological study of a sural nerve biopsy by light microscopy and on teased-fiber preparations. The sarcoid granulomas were multiple, especially in case 2; they were sparse in the epineurial and perineurial spaces and absent in the endoneurium, whose interstitial component contained cellular infiltrations of scattered macrophages. Blood vessel changes were a constant morphological feature. The mechanisms that possibly contribute to the pathogenesis of the sarcoid neuropathy are discussed in relation to previous reports.

[Comparison between one and two dimensional echocardiography in the study of segmentary kinetics of the left ventricle in post-infarct ischemic myocardiopathy]. / Confronto tra la metodica ecocardiografica mono e bidimensionale nello studio della cinetica segmentaria del ventricolo sinistro nella miocardiopatia ischemica postinfartuale.

Sixty two-dimensional M-mode echocardiograms of myocardial infarction patients, performed 3--6 months after acute attack, were compared with those of 30 normal subjects. In one-dimensional echocardiograms, the dimensions of the left ventricle and some segmentary signs of contractility such as diastolic thickness, excursion and systolic thickening of the septum and the posterior wall of the left ventricle were examined, in two-dimensional echocardiograms the contractility of single areas was compared to those adjacent. In heart attack patients parameters studied were changed in a statistically significant way (p less than 0,001); the degree of correlation between the site of hypo-akinesis and the ECG necrosis site was quite high; compensatory hyperkinesia was frequently found in the area diametrically opposite to dyskinetic areas. The two-dimensional examination was also very sensitive especially in the diagnosis of aneurysm, which is sometimes not noted in M-mode.

[Clinical evaluation of the therapeutic effect of D-L-carnitine in the acute phase of myocardial infarct in relation to the behavior of the serum myoglobin concentration curve]. / Valutazione clinica dell'effetto terapeutico della D-L-carnitina nella fase acuta dell'infarto del miocardio in riferimento al comportamento della curva di concentrazione serica della mioglobina.

Clinical experience carried out on 40 patients with AMI - 22 of them treated with 15 g daily of D-L-Carnitine and 18 untreated - is reported. Our interest was to study the therapeutic action of this drug evaluating if it was able to modify the curve of serum myoglobin level released from necrotic or ischaemic areas. The conclusion is drawn that this drug could act feebly only during the earlier stages of AMI, but many reserves are expressed.

[Paradoxical movement of the interventricular septum and LAE in a case of complex congenital cardiopathy in an adult with predominant overloading of the right ventricle pressure]. / Movimento paradosso del setto interventricolare ed EAS in un caso di cardiopatia congenita complessa dell'adulto a prevalente sovraccarico di pressione del ventricolo destro.

A casually observed case of complex congenital cardiopathy in an adult marked by ECG LAE, and paradoxical movement of the interventricular septum when examined echocardiographically is reported. Haemodynamic investigation established the persistence of a left vena cava superiore draining into the coronary sinus, pulmonary stenosis with a 55 mmHg transvalvular gradient, and a small PDA with left-to-right shunt equal to 20% of the pulmonary capacity. The case is presented on account of the infrequent association of these defects, the unusual ECG LAE, and above all on account of the echocardiographic picture of paradoxical movement of the IVS in the presence of right ventricle overloading.