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Biomedical subjects

G Colombo

Publications and source records attributed to G Colombo.

At least 55 records · Page 3Linked to original sources
PubMed2000

[Videolaparoscopic cholecystectomy. Experience and results in 1019 cases].

BACKGROUND: Laparoscopic cholecystectomy is now worldwide considered the elective therapy for biliary lithiasis. Morbidity, mortality and conversion rates reported in the literature are assessed between 1 and 6%, 0 and 0.9%, 3.6 and 7.2% respectively. Data on personal experience with 1019 attempted laparoscopic cholecystectomy are reported. METHODS: In the period between 1991 and 1997 1019 laparoscopic cholecystectomy were performed. Patients were 361 males and 658 females (ratio M:F 1:2), with an average age of 51 years (range 5-85). Indications were: 647 symptomatic cholelithiasis, 28 hydrops, 121 empyemas, 76 cholecystocholedocolithiasis and 13 alithiasic cholecystopathy. RESULTS: Conversion was necessary in 61 cases, with a conversion rate of 6%. Mean duration of surgery was 65 minutes (range 30-240) with a mean hospital stay of 2.1 days (range 1-10). No deaths occurred in our series, with a morbidity rate of 1.8% (18 cases, 7 major and 11 minor). Only 1 case of bile duct injury (0.1%) is reported. CONCLUSIONS: In consideration of low conversion rate, low early and late morbidity, absence of bile duct injury, advantages for the patient and the opportunity of evolution of this surgery, laparoscopic cholecystectomy can be considered the standard treatment for biliary lithiasis.

Adolescent↗
PubMed2000

Alpha-melanocyte-stimulating hormone peptides inhibit HIV-1 expression in chronically infected promonocytic U1 cells and in acutely infected monocytes.

The purpose of the present research was to determine if alpha-melanocyte-stimulating hormone (alpha-MSH) and its C-terminal tripeptide [alpha-MSH (11-13), KPV] alter HIV expression in infected cells. The results indicate that chronically HIV-1-infected promonocytic U1 cells produce alpha-MSH and that immunoneutralization of the endogenous peptide enhances HIV expression. Because U1 cells express the alpha-MSH receptor 1 (MC1R), an autocrine-inhibitory circuit based on the peptide and its receptor likely occurs in these cells. To determine effects of pharmacological concentrations of alpha-MSH peptides on HIV expression, we measured p24 antigen release by TNF-alpha-stimulated U1 cells exposed to a wide range of concentrations of synthetic alpha-MSH and KPV. Viral expression was reduced by both peptides. KPV also effectively reduced HIV replication in acutely infected monocyte-derived macrophages (MDM). The basis of the peptide influence on viral replication is at the transcriptional level; KPV inhibited activation of NF-kappaB that is known to enhance viral expression. Endogenous alpha-MSH likely contributes to natural defense against HIV. However, greater concentrations of synthetic peptide are much more effective in reducing HIV expression in infected cells.

DNA, Viral↗
PubMed2000

Laparoscopic versus open splenectomy: a comparative study.

Laparoscopic splenectomy (LS) is gaining wide acceptance as a safe, effective alternative to open splenectomy (OS) in the treatment of hematologic disorders in adult and pediatric patients, with low conversion rates and complications. The aim of this retrospective case-control study was to compare two cohorts of patients, with similar characteristics, who underwent OS or LS in a single institution. The medical records of the initial 20 consecutive patients who underwent LS were reviewed and compared with a control group of 28 patients undergoing OS, matched for age, gender, diagnosis, splenic size and weight, and American Society of Anesthesiologists score. Data were collected regarding operative time, blood loss, blood transfusions, pathologic findings, accessory spleen detection, complications, ileus duration, and postoperative hospital stay. Nineteen patients underwent attempted LS. One procedure (5%) was converted to OS for uncontrolled hilar bleeding. Accessory spleens were detected in two cases in the LS group compared with four cases in the OS group (14%). Mean operative time was 165 minutes (range: 100-240 minutes) for LS and 114 minutes (75-180 minutes) for OS (P < 0.001). In the LS group a regular diet was tolerated 36 hours (range: 24-48 hours) after surgery compared with 72 hours (range: 48-96 hours) for the OS group (P < 0.001), and mean postoperative hospital stay was 4.1 days (range: 3-8 days) for LS, compared with 8.1 days (range: 5-12 days) for OS (P < 0.001). No differences were observed in blood loss, complication rates, or transfusion requirements. Compared with OS, LS requires more operative time (showing a learning curve), is comparable in blood loss, transfusion requirements, complication rates, and detection of accessory spleens and appears to be superior in terms of return of bowel function and hospital stay.

Adolescent↗
PubMed2000

Different sensitivity to ethanol in alcohol-preferring sP and -nonpreferring sNP rats.

BACKGROUND AND OBJECTIVES: Clinical research has proposed that initial sensitivity to ethanol may be negatively correlated with levels of subsequent ethanol intake; consistently, alcohol-preferring P rats were found to be less sensitive to the ataxic and sedative/hypnotic effects of ethanol than -nonpreferring NP rats. The present study investigated the initial sensitivity to the ataxic and sedative/hypnotic effects of ethanol and to the sedative/hypnotic effects of pentobarbital and diazepam in selectively bred Sardinian alcohol-preferring sP and -nonpreferring sNP rats. METHODS: In experiment 1, time to lose (onset) and regain (sleep time) the righting reflex after the acute intraperitoneal (ip) administration of 3.0 and 3.5 g/kg ethanol were measured in sP and sNP rats. In experiment 2, sP and sNP rats were required to perform a motor coordination task on a Rota-Rod after the acute intragastric administration of 2.0, 2.5, and 3.0 g/kg ethanol. Experiment 3 assessed onset and sleep time in sP and sNP rats after the acute injection of pentobarbital (40 mg/kg; ip) and diazepam (15 and 20 mg/kg; ip). RESULTS: In experiment 1, sP rats took shorter times to lose the righting reflex and regained this reflex over longer periods of time and at lower blood ethanol levels than sNP rats. In experiment 2, ethanol affected motor coordination to a greater extent in sP than sNP rats. In contrast, results from experiment 3 showed that sP and sNP rats were not differentially sensitive to the sedative/hypnotic effects of pentobarbital and diazepam. CONCLUSIONS: The results of experiments 1 and 2 suggest that sP rats possess a genetically determined, greater sensitivity to the motor impairing and sedative/hypnotic effects of ethanol than sNP rats. Although caution should be adopted before hypothesizing any comparison to humans, these results may feature sP rats as an experimental model of those subsets of human alcoholics with initial high sensitivity to ethanol challenges. Finally, the results of experiment 3 suggest a minimal involvement of the benzodiazepine and barbiturate recognition sites in the differential sensitivity to ethanol of sP and sNP rats.

Alcohol Drinking↗
PubMed2000

[Hernia repair with prolene mesh according to the Lichtenstein technique. Results of 692 cases].

BACKGROUND: Inguinal hernia repair with prolene mesh according to Lichtenstein "tension free" technique has gained great acceptance worldwide, showing efficacy to consolidate the posterior wall of the inguinal canal and to reduce recurrence risk because of tension on suture lines and postoperative pain. Personal experience of 692 hernias treated with this technique is reported. METHODS: From January 1989 to December 1997, 692 patients were treated according to Lichtenstein at the General Surgery Department of the San Gerardo Hospital. Mean age was 60 years (range 18-88) with a male: female ratio of 13:1. Surgery was performed under local anesthesia in 185 cases, under epidural anesthesia in 317 and under general anesthesia in 190. Hernia was primitive in 647 cases (411 obliquo-external and 236 direct), while in 45 patients it was a recurrent hernia. In this series, 619 patients had monolateral inguinal hernia, while 73 had a bilateral one. In 40 cases hernia was incarcerated and in 8 strangulated. RESULTS: Mean hospital stay was 2.3 days (range 1-8). Eleven (1.6%) early complications, were observed, with one periprosthetic infection which resolved after patch removal, 3 hematomas, 2 seromas and 2 wound infections. Furthermore, there were 32 (4.6%) late complications with only one recurrence (0.14%) in this series and 25 cases of persistent nerve irritation. CONCLUSIONS: The results obtained with Lichtenstein "tension free" repairs of inguinal hernias confirmed this technique as easy to perform, also under local anesthesia, and associated with low rates of complications and without recurrences.

Adolescent↗
PubMed2000

[Mechanical ventilation in acute respiratory distress syndrome. New Trends].

Adult Respiratory Distress Syndrome (ARDS) is characterized by an inflammatory process affecting endothelial and epithelial lung tissue, with occurrence of hypoxemia, bilateral X-ray infiltrates, in absence of cardiogenic edema. The introduction of Computerized Tomography brought some improvements in understanding the ARDS lung, leading to a pulmonary model made up of three zones: 1) normally inflated, 2) recruitable and 3) consolidated. It has now been well established that mechanical ventilation of ARDS lung presents some iatrogenic effects that may affect mortality. Several mechanisms are considered responsible of ventilator-associated lung injury (VALI): high inspired oxygen fraction, high inspiratory plateau pressure and large tidal volume, and intratidal collapse and reinflation of alveolar units. In these years, different ventilatory strategies in the treatment of ARDS patients have been suggested to decrease and to prevent VALI. The most important one seems to be the application of an appropriate value of tidal volume and positive end-expiratory pressure (PEEP). Several randomized studies, which compared low versus high tidal volumes, have recently been finished. Despite some differences, it seems that a ventilatory management limiting inspiratory plateau pressure to 35 cmH2O or lower may be useful to reduce VALI and mortality, also in association with a PEEP level sufficient to decrease the end-expiratory collapse. Another useful ventilatory tool for improving gas exchange and decreasing VALI in ARDS patients is likely the prone positioning, even if further studies are necessary to understand how this maneuver may really affect mortality. Another therapeutic instrument for improving oxygenation in ARDS patients is the inhalation of NO. Unfortunately, this pharmacological agent does not seem to affect the outcome of these patients.

Acute Disease↗
PubMed2000

[Sequential endo-laparoscopic treatment in patients with common bile calculi].

BACKGROUND: Laparoscopic treatment of common bile duct (CBD) stones is gaining great acceptance worldwide, but actually it requires skills and technologies too expensive for a great part of general surgeons. So endoscopic removal of CBD stones before cholecystectomy is usually performed. Since 1991 in our department we started a policy of selective preoperative cholangiopancreatography (ERCP) in patients suspected for choledocholithiasis and waiting for laparoscopic cholecystectomy. METHODS: A retrospective study has been made on a population of 1100 patients who underwent elective laparoscopic cholecystectomy in the period between January 1991 and December 1997. They were 391 male and 719 female with a mean age of 52 years, 126 of whom (11.5%) were selected to have ERCP preoperatively because they had clinical, biochemical and ultrasound signs of the presence of common bile duct stones (CBDS). RESULTS: Successful cannulation of the CBD was achieved in 124 cases (98.4%), with failures due to ampullary diverticula. In 7 cases (5.5%) a precut was necessary to obtain cannulation. Sphincterotomy was performed in 113 patients (89.7%). In 93 patients (73.8%) stones were found (87 macrolithiasis and 6 microlithiasis); in 91 (97.8%) stones were removed in one (87) or two (4) endoscopic session. There were 2 major complications (one bleeding and one severe pancreatitis) due to ERCP or a sphincterotomy. Two patients developed symptoms from unsuspected common bile duct stones after LC and were removed endoscopically. No complications during LC were due to ERCP or ES. CONCLUSIONS: Selective preoperative ERCP is an effective way of clearing the CBD stones before laparoscopic cholecystectomy, with low rate of complications related to endoscopic and laparoscopic procedures, and short mean hospital stay (5.5 days), according to the concept of minimally invasive treatment.

Adolescent↗
PubMed1999

Ethanol markedly increases "GABAergic" neurosteroids in alcohol-preferring rats.

Alcohol administration (1 g/kg, i.p.) increased the levels of the neurosteroids 3alpha-hydroxy-5alpha-pregnan-20-one (allopregnanolone) and 3alpha,21-dihydroxy-5alpha-pregnan-20-one (allotetrahydrodeoxycorticosterone, THDOC) in the cerebral cortex and hippocampus both in alcohol-naive Sardinian alcohol-preferring (sP) and -non-preferring (sNP) rats (two rat lines selectively bred for alcohol preference and non-preference, respectively). However, the increase reached several fold higher levels in sP than in sNP rats (6-24 vs. 2-11 fold the basal levels, respectively). Since the two neurosteroids are the most potent endogenous positive modulators of GABA(A) receptors and elicit anxiolytic and rewarding effects, while voluntary alcohol consumption produces anxiolytic and rewarding effects in sP but not in sNP rats, the results suggest that the neurosteroids may play a role in the anxiolytic and rewarding effects of alcohol in sP rats.

Alcohol Drinking↗
PubMed1999

Autoradiographic analysis of 5-HT2A binding sites in the brain of Sardinian alcohol-preferring and nonpreferring rats.

The density of 5-HT2A binding sites in the brain of Sardinian alcohol-preferring (sP) and nonpreferring (sNP) rats was evaluated, using [3H]ketanserin for quantitative autoradiography. The highest [3H]ketanserin binding levels were found in the anterior olfactory nucleus, prefrontal cortex, medial prefrontal cortex, post-genual anterior cingulate cortex, insular cortex and claustrum. Statistically significant differences between sP and sNP rats were found in prefrontal cortex, medial prefrontal cortex and post-genual anterior cingulate cortex, where sP rats showed about 20% lower [3H]ketanserin binding levels. No significant difference was found in other areas, although some of them showed slightly lower [3H]ketanserin binding density in sP rats. The 5-HT2A receptor agonist, (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-amino-propane hydrochloride (DOI), microinjected into the medial prefrontal cortex, induced a lower number of wet dog shakes in sP than in sNP rats. These results indicate a different density of 5-HT2A binding sites, and a different functional regulation of 5-HT2A receptor mechanisms in discrete brain areas of sP, in comparison to sNP rats. These findings, and those showing lower levels of 5-HT in the frontal cortex of sP rats, suggest that altered 5-HT function in fronto-cortical areas could be linked to the genetic predisposition to high voluntary ethanol intake in these rats.

Alcohol Drinking↗
PubMed1999

DNA typing of maternal HLA in congenital complete heart block: comparison with systemic lupus erythematosus and primary Sjögren's syndrome.

OBJECTIVE: To investigate which maternal HLA allele or haplotype is primarily associated with isolated congenital complete heart block (CCHB) in offspring. METHODS: HLA class II typings were assessed by line probe assay and polymerase chain reaction-sequence-specific oligonucleotide probe methods, and HLA class I by the microlymphocytotoxicity test, in 13 Italian anti-Ro-positive mothers of children with CCHB and 41 anti-Ro-positive mothers with healthy children (20 mothers with systemic lupus erythematosus [SLE] and 21 with Sjögren's syndrome [SS]). Anti-Ro antibodies were studied by immunoblot. RESULTS: HLA-DRB1*03011 and DRB1*03011; DQA1*0501;DQB1*0201 were more frequent in mothers of infants with CCHB than in mothers who had SLE, but not in mothers who had SS and whose children were healthy. Mothers of infants with CCHB were either HLA-B5/35, B17, or B44 positive and had a higher prevalence of B44;DRB11;DQA1*0501;DQB1*0301 and isolated anti-52-kd antibodies, which were absent in SS and SLE controls. CONCLUSION: Mothers of infants with CCHB presented a strong genetic similarity to mothers who had SS, except for HLA class I phenotype. HLA-DRB1*03011;DQA1*0501;DQB1*0201 seemed not to be primary CCHB-associated genes, but were involved in an SS-like anti-Ro/La response. The combined presence of HLA-DRB1*03011 and anti-52-kd SSA/Ro antibodies conveyed the highest risk of giving birth to an affected child.

Alleles↗
PubMed1999

Antidepressant-like effect of ethanol revealed in the forced swimming test in Sardinian alcohol-preferring rats.

RATIONALE: A large body of evidence indicates high comorbidity between depression and alcohol abuse. The self-medication hypothesis proposes that depressed subjects may abuse ethanol because it reduces the symptoms of depression. The present study evaluated whether ethanol may exert an antidepressant-like action in genetically selected alcohol-preferring rats, either Sardinian alcohol-preferring (sP) or Marchigian Sardinian alcohol-preferring (msP) rats, and for comparison in Sardinian alcohol-non-preferring (sNP) rats. METHODS: The forced swimming test (FST) was used to evaluate the antidepressant-like action of ethanol; in this test the effect of ethanol ingestion on the immobility time was determined. RESULTS: Ethanol-naive sP rats exhibited a longer period of immobility in comparison to sNP rats. Both in ethanol-naive sP and msP rats, voluntary ethanol drinking reduced the immobility time. A similar effect was obtained when repeated (five or nine) intragastric administrations of 0.7 g/kg ethanol were given during the 24 h prior to the test in msP and in sP, but not in sNP rats. Desipramine, like ethanol, sharply reduced immobility at doses of 5 or 20 mg/kg, given 3 times in the 24 h before the test in msP rats. The reduced immobility induced by ethanol in msP rats was apparently not the consequence of a general motor activation, because 9 IG administrations of ethanol, 0.7 g/kg, failed to alter locomotor activity in the open field test. Moreover, blood alcohol levels and rectal temperature of msP, sP and sNP after IG ethanol administration were not statistically different. CONCLUSIONS: The present results provide evidence for an antidepressant-like action of ethanol in sP and msP rats and suggest that this action may contribute to sustain their high ethanol drinking.

Alcohol Drinking↗
PubMed1999

Voluntary control of human gait: conditioning of magnetically evoked motor responses in a precision stepping task.

The aim of this study was to investigate visuomotor control during human gait. It was assumed that visual input should modulate transcranially evoked motor potentials (EMPs) during walking. The effect of transcranial magnetic stimulation (TMS) in a visually guided precision stepping task was compared with that during normal gait. EMPs were studied in tibialis anterior (TA), gastrocnemius (GM), and abductor digiti minimi (AD) muscles during treadmill walking. In both stepping tasks, a facilitation of EMPs was observed prior to activation of the respective leg muscle. EMP facilitation proved to be modulated throughout the stride cycle when normalising EMP with respect to the underlying electromyogram (EMG). Facilitation was strongest in TA prior to the swing phase. Significant differences of EMP facilitation between the visual and control tasks were present. In the visual task, maximal facilitation of TA EMPs prior to and during the swing phase was decreased compared to the control task. Conversely, there was increased facilitation of GM EMPs during swing phase of the visual task, prior to the heel strike and prior to the plantarflexion, which was the moment when the target was hit. Thus, the effect of visual input upon EMPs in TA and GM was differential and reciprocal according to the respective functional state. The results support the hypothesis of a conditioning effect of visual or, alternatively volitional, drive on EMPs during stepping.

Adult↗
PubMed1999

Gamma-hydroxybutyrate increases gastric emptying in rats.

The influence of gamma-hydroxybutyrate (GHB; 10, 50 or 100 mg/kg orally) and of its receptor antagonist, NCS-382 (25, 100 or 200 mg/kg orally, and 100 or 200 mg/kg intraperitoneally), on gastric emptying was studied in rats by measuring the serum level of acetaminophen (20 mg/rat orally, 30 min after GHB or NCS-382) 15, 30, 45 and 60 min after acetaminophen administration, or the amount of acetaminophen still present in the stomach 30 min after its administration. The highest dose of GHB produced a significant increase in 15 and 30 min serum levels of acetaminophen, indicating an acceleration of gastric emptying. A similar result was obtained with the prokinetic drug cisapride, at the oral dose of 2 mg/kg. On the other hand, NCS-382 significantly and dose-dependently reduced the serum levels of acetaminophen at every time of blood sampling, indicating a delay of gastric emptying, an effect confirmed by the amount of acetaminophen still present in the stomach 30 min after administration. Moreover, NCS-382 antagonized the prokinetic effect of GHB. These results may suggest for GHB (and/or possibly for its metabolites) a role in rat stomach motility.

Acetaminophen↗
PubMed1999

Contribution of GABA(A) and GABA(B) receptors to the discriminative stimulus produced by gamma-hydroxybutyric acid.

The present study examined the involvement of GABA(A) and GABA(B) receptors in the discriminative stimulus effects of gamma-hydroxybutyric acid (GHB). Rats were trained to discriminate either 300 or 700 mg/kg GHB IG from water using a T-maze, food-reinforced drug-discrimination procedure. The direct GABA(B) agonist, baclofen, substituted completely for both training doses of GHB; its potency to substitute for GHB increased moderately as the training dose of GHB was increased. The positive GABA(A) modulator, diazepam, substituted partially for 300 mg/kg GHB, but failed to elicit GHB-appropriate responding in rats trained with the higher GHB dose. Finally, the GABA(B) antagonist, CGP 35348, completely blocked the discriminative stimulus effects of the high training dose of GHB, but only partially antagonized the effects of the low training dose. These results suggest that (a) GHB produces a compound stimulus, and (b) both GABA(B)- and GABA(A)-mediated cues are prominent components of this compound stimulus; the contribution of each component, however, appears to vary as the training dose of GHB is increased.

3-Hydroxybutyric Acid↗
PubMed1999

Reduction of blood ethanol levels by the gamma-hydroxybutyric acid receptor antagonist, NCS-382.

The present study demonstrates that the gamma-hydroxybutyric acid receptor antagonist, NCS-382, markedly reduces blood ethanol levels (BELs) in rats when ethanol is administered via the intragastric route, whereas it is completely ineffective when ethanol is injected IP. The reducing effect of NCS-382 on BELs is likely due to a lessened absorption of ethanol from the gastrointestinal tract.

Animals↗
PubMed1999

Salvia miltiorrhiza extract inhibits alcohol absorption, preference, and discrimination in sP rats.

Experiment 1 of the present study investigated the ability of a standardized extract of Salvia miltiorrhiza in reducing voluntary ethanol intake in ethanol-preferring rats of the sP line. Ethanol intake occurred under the two-bottle free-choice regimen between 10% (v/v) ethanol and water in daily 4-h scheduled access periods; water was present 24 h/day. Intragastric administration of 200 mg/kg Salvia miltiorrhiza extract resulted in approximately 40% reduction in ethanol intake and preference throughout the 4-day treatment. This effect of Salvia miltiorrhiza extract was likely due to its ability of altering ethanol absorption from the gastrointestinal tract. Indeed, Experiments 2 and 3 of this study demonstrated that 200 mg/kg Salvia miltiorrhiza extract reduced blood ethanol levels (BELs) up to 60% in comparison to control rats, when ethanol was given IG, whereas it failed to modify BELs when ethanol was injected IP. The reducing effect of Salvia miltiorrhiza extract on ethanol absorption may have therefore resulted in an attenuated perception of the psychoactive effects of ethanol sought by ethanol-drinking rats. Consistently, the results of Experiment 4 of the present study demonstrated that a combination of 200 mg/kg Salvia miltiorrhiza extract IG and 1 or 2 g/kg ethanol IG resulted in a partial blockade of the discriminative stimulus effects of ethanol in sP rats trained to discriminate these doses of ethanol from water in a drug discrimination procedure. Collectively, the results are discussed as being suggestive that drugs curbing ethanol absorption from the gastrointestinal tract may constitute a novel strategy for controlling excessive alcohol consumption in human alcoholics.

Alcohol Drinking↗
PubMed1999

Post-traumatic stress disorder and major depression among Italian Nazi concentration camp survivors: a controlled study 50 years later.

BACKGROUND: The study aimed to assess the current and lifetime rates of post-traumatic stress disorder (PTSD) and major depression (MDD) among Nazi concentration camps survivors. METHODS: We investigated 51 Italian political deportees and 47 Resistance Movement veterans who reported traumatic experiences during active service. The Structured Clinical Interview for DSM-IV was used to assess the presence of PTSD and MDD. The Dissociative Experiences Scale and the shorter version of the Hopkins Symptoms Checklist were also administered. RESULTS: The lifetime rates of PTSD and MDD were 35.3% and 45.1% respectively among deportees and 4.3% and 6.4% among former partisans. The current rates for PTSD and MDD were 25.5% and 33.3% among deportees and 4.3% and 4.3% among former partisans. Dissociative symptoms were more severe among deportees than among Resistance movement veterans. CONCLUSIONS: Concentration camp internment, even for political reasons, appears to have severe long-term psychiatric consequences.

Aged↗