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Biomedical subjects

P Marini

Publications and source records attributed to P Marini.

At least 91 records · Page 5Linked to original sources

[Ultrasonics diagnosis of venous thrombosis].

Ultrasound phlebosonometry was employed in the examination of 54 subjects with phlebosonometric acute or recurrent in 20, chronic in 34 cases. The results of one or more phlebosonometric examinations were compared with the phlebograms. It was found that ultrasound investigation was reliable more for high (91%) than for low (65%) lesions and for acute (85%) as opposed to chronic (70%) thrombosis. The method is seen as of great importance in cases of phlebothrombosis, especially in acute femoroiliac forms. Even though it is a qualitative examination, and hence cannot take the place of angiography, it can nevertheless limit the use of the latter in cases where it could be dangerous.

Acute Disease↗

Acetylcholinesterase activity and molecular forms during denervation and reinnervation in extensor digitorum longus muscle of the rat.

The four principal molecular forms of acetylcholinesterase characteristic of the mammalian muscle (16.1 S., 12.5 S, 10.2 S, and 3.6. S) were identified by sucrose gradient sedimentation as the four activity peaks H, H1, M and L. After denervation obtained by crushing the sciatic nerve five stages of the denervation-reinnervation process were examined. Days 7, 14, 22, 30, and 60 were chosen on the basis of previous electrophysiological and histochemical studies. The AChE activity showed an initial drop followed by recovery after nerve arrival at the muscle which was completed by day 60. Marked changes in the relative proportions of the four molecular forms were observed. The 16.1 S almost disappeared during the denervation period, reappeared after nerve arrival and was completely restored at day 60. Changes were also observed in the intermediate and lower forms and were tentatively related to processes of degradation, reaggregation and de novo synthesis. A comparison of the present data with those from parallel electrophysiological and histochemical studies suggests the presence and the functional role of molecular forms other than 16S in the neuromuscular junction.

Acetylcholinesterase↗

Inhibition of the membrane localization of p21 ras proteins by lovastatin in tumor cells possessing a mutated N-ras gene.

Mutated ras genes are found in a variety of human tumors. For biological activity the gene product p21 ras needs to be bound to the cell membrane by a farnesyl residue. Treatment of tumor cells with lovastatin reduces the availability of farnesyl pyrophosphate for the modification of the ras proteins. The membrane localization of p21 ras has been reduced by 30-36% after the tumor cells have grown in the presence of 10 microM lovastatin for 7 days. The extent of the inhibition depends on the growth kinetics of the cell lines.

Acute Disease↗

Combined laparoendoscopic approach for biliary lithiasis treatment.

BACKGROUND/AIMS: The treatment of common bile duct stones diagnosed during videolaparoscopic cholecystectomy is still under debate. In cases of suspected common bile duct stones, a double approach with endoscopic retrograde cholangiopancreatography either prior to, or following videolaparoscopic cholecystectomy is the current routine in many centers. An intraoperative endoscopic retrograde cholangiopancreatography with endoscopic papillosphincterotomy and stone extraction has recently been proposed. METHODOLOGY: We compared the approaches for suspected common bile duct stones in 21 cases of combined intervention endoscopic retrograde cholangiopancreatography during videolaparoscopic cholecystectomy to 17 cases of sequential intervention (endoscopic retrograde cholangiopancreatography prior to videolaparoscopic cholecystectomy). Complications and postoperative monitoring are discussed and reported on the basis of hospital stay. RESULTS: Although the efficacy and the complications are similar, patients treated with the sequential approach stayed in the hospital longer because of the double monitoring period during both after endoscopic retrograde cholangiopancreatography and after videolaparoscopic cholecystectomy. CONCLUSIONS: A combined approach to suspected common bile duct stones during videolaparoscopic cholecystectomy could be an effective and a financially worthwhile treatment.

Cholangiography↗

[The Bengmark tube in surgical practice and in the critically ill patient].

Enteral nutrition (EN) is increasingly used to minimize the rate of septic complications related to bacterial translocation, due to its effectiveness and low cost. Bengmark's self-propelling auto-positioning feeding tube (SPT) absorbs and uses gut motility for rapid transport to the upper small intestine, thereby allowing uninterrupted EN both in surgical and critically ill patients. We report on our experience with 175 SPTs applied over the period from December 1996 to February 2000, and analyse the safety, compliance, and indications of SPT in surgical and ICU practice. Open study: feasibility of insertion, time and rate of placement, compliance and complications related to the tube or to EN were studied. SPTs were successfully placed in 40 patients before liver resection, in 32 patients before extensive maxillo-facial surgery MFS and prior to colon resections in 10 cases. SPTs were also applied in 56 patients with acute vascular neurological diseases, 22 in pancreatic diseases and in another 15 critically ill patients. 92.5% of SPT's crossed the pylorus, while only 7.5% stopped in the stomach and 3.4% in the duodenum; 89.14% reached the first jejunal loop. The tip of the tube reached its final position within a mean period of 5.2 hours, 8% instantly and all within 24 hours. Enteral nutrition was started immediately after introduction of the tube into the stomach. The compliance was excellent, even in maxillo-facial surgery patients: only 2/76 patients (2.6%) showed poor compliance. There were no cases of aspiration pneumonia or other complications related to SPT. Polymeric nutrition was usually supplied at a starting flow rate of 45 ml/hour and rapidly increasing over the following 48 h. Eleven patients experienced diarrhoea and 6 abdominal distension, leading to a temporary reduction of the EN flow rate. Clogging of the SPT occurred in 13 patients: 7/13 were cleansed with pancreatic enzymes, but 6 had to be replaced. SPT is ideal for intensive EN and is characterised by minimal complications and excellent patient compliance.

Critical Illness↗

[Cystic pancreatic tumors. Review of literature and proposal of a diagnostic-therapeutic pathway].

In this paper the Authors consider the epidemiological, clinical, pathological, instrumental, chemical and physical findings of every type of pancreatic cystic lesions. They perform a critical examination of each of them. In this way, they can identify the most important features of every single class. A pathway consisting in four main groups of instrumental and chemical tests (abdominal ultrasonography / EUS, CT, MR, FNA / biopsy/ assay of tumoral markers and amylase of cystic fluid) was chosen to know all these informations according to careful principles of specificity, sensitivity and diagnostic accuracy taken from international scientific literature. In each subgroup of cystic pancreatic tumor, at last, the most reliable therapeutic project is suggested according to the common international scientific agreement.

Aged↗

[Spontaneous reparation of post-traumatic tympanic perforation: an experimental study in rats].

In most patients tympanic membrane perforation spontaneously repairs itself. Nonetheless, in several cases the perforation persists due either to traumatic or phlogistic damage. Although the membrane perforation healing process has been under study for over a century there are still two contrasting theories. One of these theories asserts that repair takes place through the growth of granulation tissue while the other believes that epithelial migration is at the basis of healing. In the present study an experimental animal model (rat) was used in order to assess the staging of the natural evolution of post-traumatic membrane perforation and to characterize, from a morphological and sub-microscopic point of view, the cellular population and microstructural aspects of the extracellular matrix. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were employed to evaluate the progress in tympanic membrane healing and to make a comparison with the most recent theories. Eighteen Sprague-Dawley rats weighing 230-260 gr of the same age (10 weeks) were used in the study. The animals were anesthetized by intraperitoneal injections of Na-pentobarbital (NembutalR) (45 mg/Kg) and, under operating microscope, bilateral perforation of the upper rear quadrant of the pars tensa was performed with a myringotomy lancet. The animals were subjected to periodic follow-ups over next 30 days. Three animals were sacrificed during each control and the tympanic membrane was removed for TEM and SEM study. On the basis of the present study the following conclusions can be drawn: a) primary healing of the lesion is through granulation tissue; b) the healed T.M. is composed of three normal layers as is the normal T.M.; c) the presence of fibroblasts in the intermediate neoformed fibrous layer leads one to conclude that its extracellular matrix is produced and organized "in situ"; d) the neoformed lamina propria has a disorganized, fibrous structure.

Animals↗

Prevention of deep venous thrombosis in vascular surgical procedures by LMW-heparin.

The risk of Deep Venous Thrombosis (DVT) in the immediate postoperative period varies from 0.8 to 96% of cases depending on major or minor operations and on age of patients. We have employed 8,000 I.U. AXa/daily of LMW-Heparin injected subcutaneously from one day preoperatively and prolonged for 8 days after surgical procedures in 40 patients operated upon by an aorto-femoral bypass in 25 cases, a femoro-popliteal below the knee in 8 and an extra-anatomical bypass in 7. The onset of DVP in the lower limbs was investigated by clinical examination, venous Doppler pressure evaluation, waveform analysis and echotomography and the 125I-Fibrinogen uptake test. There was no intraoperative increased bleeding and the preclotting of the prosthetic grafts was inaffected. A DVT was detected during the second postoperative day, by means of the 125I-Fibrinogen test in the calf of only one patient (1/40-2.5%), submitted to an aorto-bifemoral bypass, in whom the clinical pattern and ultrasound investigations were negative. The single daily subcutaneous administration has never caused side effects in the site of injection and it seems a real improvement in the heparin treatment. These results emphasize the advantage of the use of LMW-Heparins in patients submitted to arterial surgical reconstructions of the lower limbs for the prevention of the DVT.

Aged↗

Arterial repair of the lower limbs: prevention of prosthetic grafts occlusion by LMW-heparin.

The postoperative thrombosis of prosthetic grafts may be due to many factors: technical errors, poor run-off, prosthetic material, graft length, trauma by subcutaneous tunnellization or repeated microtrauma across the joint areas, evolution of atherosclerotic lesions, emorheological changes. In 50 patients submitted to surgical arterial repair of the lower limbs, we have employed 8,000 I.U. AXa/daily of LMW-Heparin, injected subcutaneously for 6 months after the operations to prevent immediate and late thrombosis. During the follow-up, one patient died, four stopped any treatment and in two the medication was changed. Hence our results are based on 43 cases: 10 patients operated upon by aorto-femoral bypass, 19 femoro-popliteal and 14 extra-anatomical procedures. During the follow-up all the patients were investigated by ultrasounds (pressure measurement, waveform analysis and duplex scanning echotomography); moreover 13/43 (30%) were studied by angioscintigraphy and 11/43 (25.5%) by a conventional or digital subtraction angiography. Thrombosis of the grafts at one year term occurred in none aorto-femoral, in one femoro-popliteal (5.2%) and in one extra-anatomical bypass (7.1%). This figure compares favourably with the results obtained in our experience in the patients treated by a variety of drugs. In such group the incidence of occlusion is 3.9% in aorto-femoral, 9.3% in femoro-popliteal and 11% in extra-anatomical grafts. Those results emphasize the possibility to improve the patency of the grafts in the arterial repair of the lower limbs by LMW-Heparin overall in femoro-popliteal and extra-anatomical areas.

Aged↗

[Electrophysiologic studies (auditory and somatosensory evoked potentials) in Friedreich's ataxia].

Auditory and somatosensory evoked potentials were recorded from 10 patients suffering from Friedreich's ataxia. All patients were subjected to audiological tests and EMG-ENG study. Acoustic evoked potentials recordings included brainstem acoustic evoked potentials and long latency components. Peripheral and central components of somatosensory evoked potentials were obtained by stimulating the median nerve at the wrist and elbow. Various abnormalities of the cortical components were observed in all patients for both acoustic and somatosensory evoked potentials. Analysis of brainstem acoustic evoked potentials and of the early components of somatosensory evoked potentials showed a different incidence of abnormalities. The main feature of brainstem acoustic evoked potential changes was the frequent absence of one or more waves; the greatest abnormalities occurred in patients whose disease was of long duration. Long latency components (N85) were significantly prolonged in all but one patient. There was often an absence or reduction of early somatosensory evoked potentials with normal or near normal latencies, even though cortical responses were markedly prolonged. The sensory conduction velocity between stimulation sites at wrist and elbow was normal in all patients. Clinically brainstem acoustic evoked potentials may prove to be a reliable means of monitoring the progression of the disease, while long latency components and somatosensory evoked potentials could be used as complementary procedures in early diagnosis.

Adolescent↗

[Neurophysiological (evoked auditory and somatosensory potentials) and neuroradiological (cranial CT) study in patients with olivopontocerebellar atrophy].

Thirteen patients affected by either dominant or recessive and/or sporadic olivopontocerebellar atrophy were studied. All patients were subjected to auditory evoked potential recordings including early and long latency components, CT scans, vestibular and EMG-ENG examinations. In nine patients somatosensory evoked potentials were also recorded. Clear-cut abnormalities in brainstem auditory evoked potentials were observed in only two patients while a slight reduction of the IV-V/I amplitude ratio was found in seven cases. N85 was increased in two patients. The main feature of somatosensory evoked potentials abnormalities was a delayed N20 in association with prolonged N13-N20 central conduction time (five patients). For all patients the CT scan varying degrees of cerebellar and brainstem atrophy. There was no clear correlation between the abnormalities revealed by neurophysiological and neuroradiological investigations and the severity and duration of the illness. It is noteworthy that auditory and/or somatosensory evoked potential changes were found in all dominant olivopontocerebellar atrophy patients.

Adolescent↗