Microglial diversity along the hippocampal longitudinal axis impacts synaptic plasticity in adult male mice under homeostatic conditions.

The hippocampus is a plastic brain area that shows functional segregation along its longitudinal axis, reflected by a higher level of long-term potentiation (LTP) in the CA1 region of the dorsal hippocampus (DH) compared to the ventral hippocampus (VH), but the mechanisms underlying this difference remain elusive. Numerous studies have highlighted the importance of microglia-neuronal communication in modulating synaptic transmission and hippocampal plasticity, although its role in physiological contexts is still largely unknown. We characterized in depth the features of microglia in the two hippocampal poles and investigated their contribution to CA1 plasticity under physiological conditions. We unveiled the influence of microglia in differentially modulating the amplitude of LTP in the DH and VH, showing that minocycline or PLX5622 treatment reduced LTP amplitude in the DH, while increasing it in the VH. This was recapitulated in Cx3cr1 knockout mice, indicating that microglia have a key role in setting the conditions for plasticity processes in a region-specific manner, and that the CX3CL1-CX3CR1 pathway is a key element in determining the basal level of CA1 LTP in the two regions. The observed LTP differences at the two poles were associated with transcriptional changes in the expression of genes encoding for Il-1, Tnf-α, Il-6, and Bdnf, essential players of neuronal plasticity. Furthermore, microglia in the CA1 SR region showed an increase in soma and a more extensive arborization, an increased prevalence of immature lysosomes accompanied by an elevation in mRNA expression of phagocytic markers Mertk and Cd68 and a surge in the expression of microglial outward K+ currents in the VH compared to DH, suggesting a distinct basal phenotypic state of microglia across the two hippocampal poles. Overall, we characterized the molecular, morphological, ultrastructural, and functional profile of microglia at the two poles, suggesting that modifications in hippocampal subregions related to different microglial statuses can contribute to dissect the phenotypical aspects of many diseases in which microglia are known to be involved.

Plasma microglial-derived extracellular vesicles are increased in frail patients with Mild Cognitive Impairment and exert a neurotoxic effect.

Extracellular vesicles (EVs) are mediators of cellular communication that can be released by almost all cell types in both physiological and pathological conditions and are present in most biological fluids. Such characteristics make them attractive in the research of biomarkers for age-related pathological conditions. Based on this, the aim of the present study was to examine the changes in EV concentration and size in the context of frailty, a geriatric syndrome associated with a progressive physical and cognitive decline. Specifically, total EVs and neural and microglial-derived EVs (NDVs and MDVs respectively) were investigated in plasma of frail and non-frail controls (CTRL), mild cognitive impairment (MCI) subjects, and in Alzheimer's disease (AD) patients. Results provided evidence that AD patients displayed diminished NDV concentration (3.61 × 109 ± 1.92 × 109 vs 7.16 × 109 ± 4.3 × 109 particles/ml) and showed high diagnostic performance. They are able to discriminate between AD and CTRL with an area under the curve of 0.80, a sensitivity of 78.95% and a specificity of 85.7%, considering the cut-off of 5.27 × 109 particles/ml. Importantly, we also found that MDV concentration was increased in frail MCI patients compared to CTRL (5.89 × 109 ± 3.98 × 109 vs 3.16 × 109 ± 3.04 × 109 particles/ml, P < 0.05) and showed high neurotoxic effect on neurons. MDV concentration discriminate frail MCI vs non-frail CTRL (AUC = 0.76) with a sensitivity of 80% and a specificity of 70%, considering the cut-off of 2.69 × 109 particles/ml. Altogether, these results demonstrated an alteration in NDV and MDV release during cognitive decline, providing important insight into the role of EVs in frailty status.

Infection prevention in endoscopy practice: comparative evaluation of re-usable vs single-use endoscopic valves.

Re-usable air/water and suction valves used in endoscopes often demonstrate risk of infection. To the authors' knowledge, the safety and efficacy of re-usable and single-use valves have not been compared to date. As such, a laboratory investigation was undertaken to compare the safety and efficacy of re-usable and single-use valves at 11 Italian endoscopy sites. Safety was evaluated by analysing the rinse liquid of reprocessed re-usable valves ready for use, and efficacy was assessed based on the completion of endoscopic procedures without valve malfunction. This study found significantly lower contamination of single-use valves compared with re-usable valves (0 vs 29.1%, respectively; P=0.007) and similar efficacy (97.6 vs 98.8%, respectively; P=ns). Microbiological analysis of the rinse liquid of reprocessed re-usable valves identified various surviving micro-organisms and highlighted their potential pathogenicity. Such data suggest that sterile single-use valves may be safer than re-usable valves, and have comparable performance.

KCa3.1 inhibition switches the phenotype of glioma-infiltrating microglia/macrophages.

Among the strategies adopted by glioma to successfully invade the brain parenchyma is turning the infiltrating microglia/macrophages (M/MΦ) into allies, by shifting them toward an anti-inflammatory, pro-tumor phenotype. Both glioma and infiltrating M/MΦ cells express the Ca(2+)-activated K(+) channel (KCa3.1), and the inhibition of KCa3.1 activity on glioma cells reduces tumor infiltration in the healthy brain parenchyma. We wondered whether KCa3.1 inhibition could prevent the acquisition of a pro-tumor phenotype by M/MΦ cells, thus contributing to reduce glioma development. With this aim, we studied microglia cultured in glioma-conditioned medium or treated with IL-4, as well as M/MΦ cells acutely isolated from glioma-bearing mice and from human glioma biopsies. Under these different conditions, M/MΦ were always polarized toward an anti-inflammatory state, and preventing KCa3.1 activation by 1-[(2-Chlorophenyl)diphenylmethyl]-1H-pyrazole (TRAM-34), we observed a switch toward a pro-inflammatory, antitumor phenotype. We identified FAK and PI3K/AKT as the molecular mechanisms involved in this phenotype switch, activated in sequence after KCa3.1. Anti-inflammatory M/MΦ have higher expression levels of KCa3.1 mRNA (kcnn4) that are reduced by KCa3.1 inhibition. In line with these findings, TRAM-34 treatment, in vivo, significantly reduced the size of tumors in glioma-bearing mice. Our data indicate that KCa3.1 channels are involved in the inhibitory effects exerted by the glioma microenvironment on infiltrating M/MΦ, suggesting a possible role as therapeutic targets in glioma.

Aortic and renal lesions in hypercholesterolemic adult, male, virgin sprague-dawley rats.

Male, virgin Sprague-Dawley rats received for periods of from 2 to 80 weeks 1 of the 3 following diets: Commercial rat chow (control diet), commercial rat chow supplemented with cholesterol (cholesterol diet) or commercial rat chow supplemented with cholic acid and taurine in equimolar amounts (cholic acid diet). Plasma cholesterol concentration was elevated in all rats kept on the cholesterol or on the cholic acid diets. Three of 8 rats kept on the control diet also developed hypercholesterolemia 80 weeks after beginning the experiment. Intimal plaques in the aorta and glomerulosclerosis were observed in all rats with plasma cholesterol concentrations above 150 mg/100 ml, including the three hypercholesterolemic controls. Cholesterol concentrations in the aorta and kidneys of the rats with these lesions were not increased above the control values while hypercholesterolemia was common to all the rats with these lesions regardless of the type of the diet.

The effect of neurotensin on the plasma cholesterol levels in the rat.

The effect of the hypothalamic tridecapeptide neurotensin (NT) on the plasma cholesterol levels was studied in the rat. 15 min after the intravenous administration of 1.25 pmol/100 g body weight NT, the concentration of the total plasma cholesterol was increased about 25% above the control values (P less than 0.001) and remained at about the same level 30 min after the injection. The hypercholesterolemic response to the intravenous administration of NT increased dose dependently (12.5 and 125 pmol). Adrenalectomy and hypophysectomy did not modify the hypercholesterolemic effect of NT. The data suggest that NT may have a role in cholesterol transport.

The effect of neurotensin on the concentration of cholesterol and bile acids in the guinea pig.

In guinea pigs, total plasma cholesterol concentrations increased above the control values after single intravenous injections and after 3 days of continuous subcutaneous administration of neurotensin (NT). A high dose of NT (125 pmol/100 g body weight) induced tachycardia and severe respiratory distress; the lowest dose (1.25 pmol/100 g body weight) had the greatest hypercholesterolemic effect 15 min after the injections. The bulk of the total plasma cholesterol was in low density lipoprotein fractions. Cholesterol increased in the same fractions after intravenous administrations of NT. NT induced a decrease in the cholesterol content in the ileum but did not affect significantly the cholesterol content in the liver, kidneys or adrenals. In 48-hr fasted controls, plasma cholesterol concentration and cholesterol content in the liver, kidneys, adrenals and terminal ileum increased; after intravenous injections of NT, plasma cholesterol concentration further increased but cholesterol content of the liver, kidneys and ileum decreased. In fed animals, the concentration of the biliary taurochenodeoxycholic acid increased above the control values 5 and 35 min after the intravenous injections of NT. In fasted controls, the total concentration of bile acids was higher than in fed controls, but only the concentration of taurochenodeoxycholic acid further increased after the injections of NT. Proportionately more taurochenodeoxycholic acid than cholesterol was present in bile after the intravenous injections of NT. These data are consistent with the hypothesis that NT has a regulatory role in intestinal cholesterol transport.

Laparoscopic re-operation from gastro-oesophageal reflux.

Since 1994 until the present day, we have had to surgically re-operate in five cases of failure with laparoscopic operations aimed at correcting gastro-oesophageal reflux disease. Two of these cases came from our own patients and three came under our observation from other centers. We applied fundoplication according to Nissen-Rossetti in three cases and the Rossetti-Hell operation in the other cases. One case involved recurrent gastro-oesophageal reflux with a short oesophagus and fundoplication raised into the mediastinum. In one other case, there was recurrent hiatal herniation with a rotary as well as axial component and consequent mediastinal occupation. The other three cases featured persistent post-operative dysphagia caused, in one case, by an error in the creation of the anti-reflux valve (perigastric cuff) and, in the other two, by erroneous choice of the anti-reflux operation: post-operative manometry showed important oesophageal hypo-dyskinesia which should have indicated partial fundoplication. All the patients underwent laparoscopic exploration. The patient with the short oesophagus had to be converted for the performance of a total duodenal diversion, while the remaining four patients underwent a total laparoscopic operation. The patient with recurrent hiatal hernia had the hernia reduced in the abdomen and combined anterior and posterior hiatoplasty. In another three cases, total fundoplication was transformed into partial fundoplication according to Toupet. The post-operative course and clinical results were excellent in all five patients. Stress is placed on the importance of accurate morphological and functional assessment of the oesophagus in the pre-operative stage so as to select the most suitable operation and in the post-operative stage in order to evaluate the causes of failure, the advantages of laparoscopy in terms of exposure of the operative field, the importance of certain technical details that optimize the results of the operation, and the efficacy of the laparoscopic approach also for the correction of most failures that demand re-operation.

Surgical palliation in pancreatic head carcinoma and gastric cancer: the role of laparoscopy.

BACKGROUND/AIMS: In all patients with pancreatic and gastric cancer we always make a laparoscopic exploration to complete the staging. Lately we have adopted the following technique for nonresectable cancers of the head of the pancreas: following endoscopic retrograde cholangiography we position a biliary stent to restore bile flow and obtain regression of jaundice, a laparoscopic-assisted gastroentero-anastomosis (GEA) is then performed as an antecolic isoperistaltic side-to-side gastrojejunostomy. Also in case of nonresectable gastric cancer we perform a laparoscopic-assisted gastrojejunostomy. METHODOLOGY: From January 1994-February 1998 we performed a total of 25 laparoscopic assisted gastrojejunostomies. We adopted this minimally invasive technique for 11 out of 20 patients (55%) with nonresectable cancers of the head of the pancreas, 7 men and 4 women, whose median age was 73 (range: 60-89). A video-assisted gastrojejunostomy was also performed in 14 patients out of 28 (50%), 10 men and 3 women, with a median age of 70 (range: 58-76), with nonresectable distal gastric cancers and 1 woman with non-resectable and obstructing duodenal cancer. The operative time of the video-assisted procedure was 35 min (range: 25-40 min). RESULTS: There were no intra-operative complications and no mortality. All the patients had a very satisfactory post-operative course, with only 1 (4%) with post-operative complications (hyperpyrexia in a patient due to an infection of the biliaryendoprosthesis, with precocious regression after replacement of the prosthesis) and minimal post-operative pain. Median post-operative hospital stay was 3 days (range: 2-4). Median survival after operation was 6 months (range: 2-12) for gastric cancer and 9 months (range: 5-15 months) for pancreatic head carcinoma. CONCLUSIONS: We believe that this technique, for the obstructive syndrome of the pylorus and duodenum, offers these patients the best results/trauma ratio. Two currently remaining types of indications for a GEA, namely non-malignant ulcer and unresectable duodenal or antropyloric obstructive cancer.

Laparoscopic treatment of peptic ulcers. A review after 6 years experience with Hill-Barker's procedure.

BACKGROUND/AIMS: This study illustrates our experience in treating duodenal ulcers by means of laparoscopy over a period of 6 years and the results after a lengthy careful follow-up. METHODOLOGY: From October 1991 to October 1997 we submitted 35 patients, 28 men and 7 women of an average age of 51 years (range: 22-78), to vagotomy with minimally invasive access: 23 Hill-Barkers, 2 Taylors, 6 thoracoscopic truncal vagotomies, and 4 laparoscopic truncal vagotomies. Of the patients submitted to surgery with the Hill-Barker technique, 8 were resistant to medical therapy, 11 decided not to continue with long-term medical therapy, 3 assumed an irregular medical therapy, and 1 who had been suffering for a long time from an ulcerous disease required vagotomy in association with laparoscopic cholecystectomy. In 16 patients a bleeding complication preceded surgery. RESULTS: In our experience, the average duration of the operation with the Hill-Barker technique is 40 min (range: 30-80 min), with return to normal feeding in 1 day without any disorders and return home on day 3 (range: 2-5). The patients have been followed for 3-54 months. One patient (4.3%) was lost during the follow-up. Twenty-one (91.3%) out of the 23 submitted to anterior superselective and posterior truncal vagotomy were pain and ulcer-free without medical therapy. There was only one relapse (4.3%) after 7 months where the patient underwent left thoracoscopic truncal vagotomy. CONCLUSIONS: In our opinion, as posterior truncal and anterior superselective vagotomy using the Hill-Barker technique guarantees the same excellent results, it is preferable due to the speed and ease of performance and to the low cost compared with other procedures which take more time (e.g., Taylor's section and suture of the anterior gastric wall) and require the use of particularly expensive equipment (e.g., Gomez-Ferrer's mechanical sectioning and suturing).

The role of diagnostic tests in therapeutic choices for gastroesophageal reflux disease.

Gastroesophageal reflux disease has different clinical presentations that require different diagnostic and therapeutic approaches. This paper describes the appropriate use of diagnostic tests before and after treatment. Each diagnostic tool is examined from a practical point of view to determine the information it can provide and its possible pitfalls, and to comment on how it can influence therapeutic choices. Performing a preoperative diagnostic evaluation is especially stressed, so as not to select the wrong patient or the wrong procedure. Finally, failures of surgery are examined to understand their causes and to prevent them. The value of the most relevant examinations for diagnosing the causes of failures and choosing the appropriate solution are discussed.

Laparoscopic colectomy: the absolute need for a standard operative technique.

BACKGROUND: The aim of this study is to review our experience performing laparoscopic colon surgery and to present the operative technique as used and standardized by us. METHODS: From April 1992 to December 1996, 158 consecutive patients underwent laparoscopic colon surgery. There were 92 females and 66 males, whose average age was 66.7 years (range 31-92); 134 patients (84.9%) were operated on for carcinoma, and the remaining 24 (14.1%) or benign disease. RESULTS: There were 117 procedures completed laparoscopically out of 158 patients (74%); 103 colon resections (18 for benign disease and 95 for malignant disease), 7 Hartmann procedures, 3 for reversal of Hartmann's procedures, 1 rectopexy, and 3 ileotrasversostomies. Conversions were required in 41 out of 158 cases (25.9%); 19 of these cases, however, were converted to a laparoscopic-facilitated procedure. The most common causes for conversion were the presence of bulky tumors and/or tumors that contaminated adjacent structures (16/158), adhesions due to previous operations (8/158) or patient obesity (5/158). There were 31 complications (19.6%), 9 of which required re-operation. There was only one recurrence (0.9%) that manifested 15 months after the procedure, at both trocar and drainage sites, and with peritoneal carcinomatosis. This occurred in a patient with rectal neoplasia who suffered a perforation of the rectum during dissection, with bowel spillage. The average number of lymph nodes harvested in resected specimens was 12.8 (range 1-41), whereas the mean distance of the tumor from the proximal margin of resection was 11.5 cm (range 5-35), and from the distal margin 7.5 cm (range 1-25). The average operative time was 165 minutes (range 40-360), and the mean hospital stay was 9.2 days (range 6-40). There were three mortalities out of 158 patients (1.9%). CONCLUSIONS: Laparoscopic colon resection for malignant lesions, performed with the highest respect for oncologic principles, has demonstrated that it is difficult to develop a barrier to wall and intraluminal recurrence. Recurrence, in our opinion, is caused by improper surgical technique. Therefore, neoplastic colon laparoscopic surgery must be the prerogative of selected and specialized centers.

[Rationale for the use of bile salts after cholecystectomy: results of a controlled clinical study using tauroursodeoxycholic acid (TUDCA)]. / Razionale all'utilizzo dei sali biliari nel paziente colecistectomizzato: risultati di uno studio clinico controllato con l'impiego dell'acido tauroursodesossicolico (TUDCA).

Cholecystectomy causes alterations in bile composition. In particular it rises the proportion of highly detergent bile acids with the possible consequence of the manifestation of dyspepsia in a high percentage of patients: this is the well-known post-cholecystectomy syndrome. In this clinical trial we studied the activity and safety of tauroursodeoxycholic acid--TUDCA--(500 mg/die) in the prevention of dyspepsia in cholecystectomized patients, in comparison with no treated group. We enrolled 203 patients (101 TUDCA--group A--and 102 control-group B). The two groups were comparable for age (47.1 years in group A and 50.7 years in group B), sex (m/f: 28/73 and 37/65 in the two groups) and for other characteristics connected to surgical procedures. After operation all patients suffered from dyspepsia symptoms. In patients treated with TUDCA we registered a prompt regression in severity of symptoms when compared with no treated group: in fact we noted a significant difference only at the first control planned after one month from operation. No difference were registered at the other controls (two and three months after operation). Two patients in A and 3 in group B manifested adverse events. In conclusion, the treatment with TUDCA, a new hydrophilic bile acid, seems to contribute to the improvement of clinical course in cholecystectomized patients.

[Filter sterilization and penetration battery]. / Filtri sterilizzanti e penetrazioni batteriche.

Currently sterilising filtration is one of the most commonly used techniques in the Pharmaceutical Industry. Some doubts and misunderstandings can, however, arise from certain aspects of this consolidated and well-known technology. Some examples? Does speaking about 0.2 or 0.22 um necessarily mean a sterilising filter? What are 0.1 um filters? How well do we understand the phenomenon of bacterial penetration in sterilising filters?

[Laparoscopic cholecystectomy in acute cholecystitis]. / La colecistectomia laparoscopica nelle colecistiti acute.

In a 18 month period 19 patients (4.7%) out of 400 affected by acute cholecystitis underwent laparoscopic cholecystectomy. In 18 cases the diagnosis was preoperative on clinical signs or ultrasound scan basis. Intraoperative and histologic confirm was obtained in all cases. Mean age was 44.9, 11 were males and 8 females. The procedure resulted longer and more difficult compared to the global series of the same period: 90 min. versus 56 min. respectively, with a difficulty score higher than 4 in 89% of cases versus 40% of the global series. Furthermore, in 56% of cases versus 23.3% of the global series an intraoperative contamination from gallbladder content was recorded. Nevertheless, only 1 (5%) minor complication was observed, in the form of omphalitis, which recovered in 2 days. Therefore, discharge was possible in average within 4 days, excluding the first two cases operated, respectively discharged in 5th and 7th p.o. day as a precautionary measure. Early coelioscopic cholecystectomy is safe and effective, if carried out by well trained surgeons, even in acute cholecystitis.

[Laparoscopic treatment of gastroesophageal reflux]. / La correzione della malattia da reflusso gastro-esofageo in laparoscopia.

Authors describe laparoscopic treatment of gastroesophageal reflux disease in 12 patients. Particular aspects related to intra-operative complications are referred. Moreover the reasons that make laparoscopic procedure advantageous are discussed.

Laparocholecystectomy. 6,865 cases from Italian institutions.

Data concerning 6,865 laparocholecystectomies have been collected retrospectively from 19 Italian groups. Only 5% of all patients were chosen for open cholecystectomy (OC). Acute cholecystitis was present in 5.6% of laparocholecystectomies (LC). Conversion to laparotomy occurred in 3.1% of patients. Mortality was 0.06%, morbidity 2.53% (general anesthesia complications 0.07%; general complications 0.07%; omphalitis 0.7%; abdominal complications 1.69%). Main duct lesions occurred in 0.26% of the patients, biliary leaks in 0.48%, bleedings in 0.75%, perforations in 0.2%. Data from literature concerning OC are compared to ours: mortality and morbidity have been lowered by LC; general and abdominal-wall complications have been drastically reduced; main duct lesions are not different.

Laparoscopic liver tumour resection with the argon beam.

Our initial experience with four minor resections for one malignant and three benign lesions is reported. Dissection was accomplished by mechanical fragmentation and hydrojet. Coagulation was effectively achieved by the argon beam system. Larger vessels were clipped. Three patients were treated laparoscopically and were rapidly discharged after an uneventful postoperative course. The other patient (small hepatocellular carcinoma in cirrhotic liver) had an intraoperative cardiac arrest, probably due to gas embolism. After restoration of normal cardiac activity, the operation was completed after conversion to an open approach. When using the argon coagulator it is necessary to prevent excessive intra-abdominal pressure due to the flow of argon gas and to avoid injury to the hepatic veins, which may cause gas embolism.

Duodenal perforations after laparoscopic cholecystectomy.

Duodenal perforations after laparoscopic cholecystectomies are rarely reported. The aim of this study is to focus on this complication and to suggest ways to reduce its occurrence and avoid diagnostic mistakes and therapeutical delays that could be fatal. We reviewed four personal cases and a number of others reported in the literature. Duodenal perforations are caused by improper use of the irrigator-aspirator device when retracting the duodenum, or by electrosurgical and laser burns. A duodenal perforation should be suspected in cases of bile leakage, peritonitis, intraabdominal or retroperitoneal collections, high serum or drainage amylase concentration, absence of bile leakage from the biliary tree, and the existence of a retroduodenal mass. Diagnosis requires a gastrografin upper GI series. Differential diagnosis is mainly with biliary lesions and other causes of peritonitis. Relaparoscopy may require intraoperative upper GI endoscopy or Kocher's duodenal mobilization to detect the perforation. Early diagnosis allows primary repair, usually by laparoscopy. Perforations of the duodenal cap are easier to diagnose and have a better prognosis than those of the descending duodenum. A lumbar abscess is a frequent complication.