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Biomedical subjects

M Montorsi

Publications and source records attributed to M Montorsi.

At least 37 records · Page 2Linked to original sources
PubMed1999

Prevalence and laparoscopic ultrasound patterns of choledocholithiasis and biliary sludge during cholecystectomy.

A prospective study of laparoscopic ultrasound (LUS) for evaluation of the common bile duct during laparoscopic cholecystectomy was started in October 1993. LUS during cholecystectomy was performed routinely to preoperatively identify unsuspected stones. Three-hundred thirty patients with symptomatic cholelithiasis were included in the study. The preoperative work-up included endoscopic retrograde cholangiopancreatography in 49 patients. Common bile duct (CBD) stones were found in 22 cases; in 19 cases the stones were removed successfully by endoscopic sphincterotomy. LUS successfully visualized the CBD in all but 10 patients (3%). CBD stones were found in 17 patients and confirmed by preoperative cholangiography and/or CBD exploration. There were two false-negative and one false-positive result for LUS. In 47 patients (14.2%) LUS detected CBD sludge as low-amplitude echoes without acoustic shadowing. The presence of CBD sludge was correlated with some biochemical and clinical variables. A significant correlation was identified between the absence or presence of CBD sludge and endoscopic retrograde cholangiopancreatography, acute pancreatitis, gallbladder sludge, age, and the levels of serum bilirubin and alkaline phosphatase. A significant difference was recorded between CBD diameter and the presence or absence of stones or sludge (p = 0.00001). In our experience, LUS allowed good diagnosis of CBD stones during laparoscopic cholecystectomy. The clinical significance of CBD sludge remains to be elucidated.

Adolescent↗
PubMed1998

Computer modeling of size and shape descriptors of alpha 1-adrenergic receptor antagonists and quantitative structure-affinity/selectivity relationships.

Computational chemistry and molecular modeling procedures allow us to define and compute ad hoc size and shape descriptors on the different prototropic forms assumed by drugs in biotest solutions. Together with experimental data measured on a well-identified target receptor, these descriptors are essential elements for obtaining simple, consistent, comparable, and easily interpretable theoretical quantitative structure-activity relationship (QSAR) models based on the ligand similarity-target receptor complementarity paradigm. In this context, quantitative size and shape affinity/subtype selectivity relationships have been modeled for a large set of very heterogeneous alpha 1a-, alpha 1b-, and alpha 1c-adrenergic receptor antagonists. The linear QSAR models generated have been validated by predicting both binding affinity and selectivity of a test set of noncongeneric antagonists. The satisfactory results obtained highlight both the simplicity and the versatility of the approach presented.

Adrenergic alpha-Antagonists↗
PubMed1998

Comparison of laparoscopic rectopexy with open technique in the treatment of complete rectal prolapse: clinical and functional results.

The aim of this retrospective study was to compare the functional and clinical results of laparoscopic rectopexy with those of the open technique in two similar groups of patients with complete rectal prolapse and fecal incontinence. Between November 1992 and June 1997, 21 patients underwent abdominal rectopexy. Thirteen patients (group A: 12 women and 1 man, mean age 52.9 years, range 28-70) and 8 patients (group B: 8 women, mean age 58.2 years, range 20-76) were submitted to Well's rectopexy by the open technique and the laparoscopic approach, respectively, without division of the lateral rectal ligaments. Assignment to each group was done randomly. Before the operation, a detailed clinical history was taken, and patients were studied with inspection and digital examination of the anorectum, proctosigmoidoscopy, determination of pancolonic transit time, dynamic defecography, anorectal manometry, and anal electromyography. After the operation, all patients underwent perineal physiotherapy, external electric stimulation, and perineal biofeedback. The mean follow-up time was 29.5 months (range 6-54) in group A and 25.7 months (range 8-45) in group B. Values were compared by chi-square, Mann-Whitney U, and Wilcoxon tests, as appropriate; differences were considered significant at p < 0.05. In both groups, dyschezia and fecal incontinence improved significantly (p < 0.05) after the operation. Basal pressure of anal sphincter, squeezing pressure, and rectoanal reflex improved without significance, whereas anoperineal pain was not significantly reduced. In group B, the postoperative hospital stay was shorter than in group A, with a marked reduction of costs. Laparoscopic Well's rectopexy has the same clinical and functional results as the open technique, with a shorter postoperative hospital stay and lower costs.

Adult↗
PubMed1997

Common bile duct exploration and laparoscopic cholecystectomy: role of intraoperative ultrasonography.

BACKGROUND: In October 1993, to detect associated common bile duct (CBD) stones, we started an evaluation program of patients with symptomatic cholelithiasis who were candidates for laparoscopic cholecystectomy. STUDY DESIGN: We used a standard preoperative algorithm and a laparoscopic ultrasonographic (LUS) examination. Preoperative endoscopic retrograde cholangiopancreatography (ERCP) was reserved for high-risk patients for CBD stones. Laparoscopic ultrasonographic examination during cholecystectomy was routinely performed to identify stones unsuspected preoperatively. Two-hundred-sixteen patients with symptomatic cholelithiasis were included in the study; 177 patients (82%) were at low risk for choledocholithiasis and 39 patients (18%) were at high risk and had preoperative ERCP. In 17 patients (43.5%) CBD stones were found, and in 16 patients (41%) they were removed by endoscopic sphincterotomy. RESULTS: In all patients, the main intra- and extrahepatic ducts were well documented by LUS, but in eight cases the distal tract of the CBD was not well-visualized. In eight patients, small stones were found in the CBD. A subsequent peroperative cholangiography or CBD exploration confirmed the diagnosis. In one patient, both LUS and cholangiography suspected a small stone; the CBD exploration did not confirm it (false positive). In two patients a small stone in the CBD was found during the followup period (two false negatives). An endoscopic sphincterotomy solved the problem. CONCLUSIONS: Laparoscopic ultrasonographic examination may be a real alternative to cholangiography during laparoscopic cholecystectomy: this may be reserved for selected instances on the basis of LUS findings. On the other hand, considerable ultrasonographic experience is required for LUS to be performed successfully.

Algorithms↗
PubMed1997

Endoscopic ultrasonography for preoperative staging of esophageal carcinoma.

Endoscopic ultrasonography (EUS) is a relatively new diagnostic method to assess the extent and the depth of infiltration of esophageal carcinoma. Since October 1990, EUS was performed in 55 patients presenting with squamous-cell carcinoma of the esophagus, 40 of whom were operated on. The first 23 patients underwent EUS with an Olympus GF-2/EU-M2 echoendoscope with a 7.5-MHz transducer; the last 32 patients underwent EUS with an Olympus GF-3/EU-M3 instrument with a 7.5-12-MHz echoprobe. In 22 patients, the procedure was not completed because of the impossibility of passing through the neoplastic stenosis. The depth of infiltration (T parameter) was correctly defined by EUS in 36 of 40 patients (90%) compared with 50% of computed tomography (CT). The 12-MHz echoprobe yielded a global accuracy in staging T parameter of 94% compared to 82% of 7.5-MHz transducer. The lymph-node involvement (N parameter) was correctly classified by EUS in 20 of 23 patients (87%) compared with 39% by CT. EUS provides a high degree of accuracy in assessing the T and the N parameter in the staging of squamous-cell esophageal carcinoma. The major problem of the instrument is still the frequent impossibility of passing through the neoplastic stenosis.

Carcinoma, Squamous Cell↗
PubMed1996

Technical difficulties and complications during laparoscopic cholecystectomy: predictive use of preoperative ultrasonography.

The aim of this study was to evaluate ultrasound findings as predictors of potential operative difficulties and complications during laparoscopic cholecystectomy (LC). From October 1993 to June 1995 a total of 143 patients with symptomatic cholelithiasis (50 males, 93 females, mean age 49.5 +/- 15 years) were evaluated by ultrasound (US) the day before LC. The US examination assessed six parameters: gallbladder (GB) volume, GB wall thickness, GB neck position, GB stone mobility, stone maximum size, and GB adhesions. On the basis of these US findings, a predictive judgment of technical difficulties was expressed by degree: easy, difficult, and very difficult. Altogether 101 patients presented with uncomplicated symptomatic cholelithiasis, and 42 had acute cholecystitis. The operation was predicted to be easy in 38% of cases, difficult in 49%, and very difficult in 13% with a good correlation with the surgeon's intraoperative judgment (r = 0.66). A significant association was found between stone mobility (r = 0.37), presence of adhesions (r = 0.36), and the difficulty of the procedure. The predictive US evaluation was significantly correlated with some intraoperative technical steps [dissection of Calot's triangle (r = 0.41), dissection of the gallbladder bed (r = 0.41)], and intraoperative bleeding (r = 0.27). Our results suggest that preoperative US is a useful screening test for patients undergoing LC, and it can help predict technical difficulties. On the other hand, a relevant number of cases still exist wherein the concordance between the preoperative US classification and the surgical findings is unsatisfactory. In this group the surgeon cannot safely rely on the US examination alone.

Adolescent↗
PubMed1996

Prevalence of antibodies to human herpesviruses 6 and 7 in early infancy and age at primary infection.

Sera from a sample of children aged 3 months to 6 years and from cord blood were tested in an indirect immunofluorescence assay (IFA) for reactivity to human herpesviruses 6 (HHV-6) and 7 (HHV-7). HHV-6 seropositivity values rose from 19% to 79.3% in the first 18 months of life, while HHV-7 seroprevalence reached a similar value (75.9%) in children aged 3-6 years. These results show that HHV-7, like HHV-6, is a prevalent virus in infancy. In cord blood sera, assayed to study infant humoral situation at birth, similar values for the two viruses (78.9% for HHV-6 and 76.3% for HHV-7) were found. HHV-6 and HHV-7 IgG antibody affinity to the corresponding antigens was assessed by the end point antibody titration in the presence and absence of urea 8M. This test distinguishes antibodies of recent (low affinity) or past (high affinity) production. Together, the data on seroprevalence and antibody affinity suggest that HHV-6 primary infection generally precedes that by HHV-7. These results are discussed in the light of a different pathogenetic role of the two viruses.

Antibodies, Viral↗
PubMed1995

Laparoscopic approach to esophageal achalasia.

Certain technical details are considered important to ease the laparoscopic performance of a Heller myotomy combined with a Dor antireflux procedure for esophageal achalasia. A special emphasis is given to intraoperative esophagoscopy combined with a mild balloon distension of the esophagogastric junction. These maneuvers prove helpful in identifying the esophagogastric region, easing the myotomy, and controlling its completeness.

Adolescent↗
PubMed1995

Efficacy of octreotide in the prevention of pancreatic fistula after elective pancreatic resections: a prospective, controlled, randomized clinical trial.

BACKGROUND: A prospective, randomized controlled clinical trial was conducted in 33 Italian surgical departments with the aim of evaluating the efficacy of octreotide in the prevention of pancreatic fistula after elective pancreatic resections. METHODS: Between July 1990 and May 1992, 278 patients were enrolled in the study. Fifty-four dropped out because of unresectable disease and six were excluded because of protocol violation; the remaining 218 were randomly assigned to the octreotide group (n = 111) or to the placebo group (n = 107). There were 131 men and 87 women with a mean age of 58.2 +/- 11.7 yrs. Pancreaticoduodenectomy was the most common operation performed (n = 143), sixty-four percent of patients had a pancreatic or periampullary cancer; chronic pancreatitis accounted for 8.2% of cases. RESULTS: Mortality rate was 6.9%. A pancreatic fistula occurred in 31 patients (14.2%), 9% in the octreotide group and 19.6% in the placebo group (p < 0.05). Morbidity rate was significantly lower in the octreotide (21.6%) than in the placebo group (36.4%) (p < 0.05). When specific pancreatic complications were grouped together and evaluated, they occurred less frequently in the treated (15.3%) than in the placebo group (29.9%) (p < 0.05). CONCLUSIONS: Octreotide was able to reduce significantly the incidence of pancreatic fistula after elective pancreatic resections.

Aged↗
PubMed1995

Comparison between thymidylate synthase B of Bacillus subtilis ATCC6633 and 168.

Bacillus subtilis 168 possesses two thymidylate synthase genes: thyA and thyB, encoding for a thermolabile and a thermostable enzyme respectively. B. subtilis ATCC6633 also possesses two thy genes, both producing thermostable enzymes. A comparison of the thymidylate synthase B amino acid sequences from the two strains shows, among others, a Pro to Ala mutation which may affect the dUMP binding site. The apparent Km and Vmax values for dUMP and tetrahydrofolate were determined at a permissive temperature for both enzymes. The kinetic data showed a significant difference in the Km, but not in the Vmax, for dUMP between the two enzymes. The Km and Vmax for tetrahydrofolate were very similar.

Alanine↗
PubMed1994

Percutaneous alcohol sclerotherapy of simple hepatic cysts. Results from a multicentre survey in Italy.

The increased use of Ultrasonography (US) has led to increased detection of simple hepatic cysts. For symptomatic cysts treatment is necessary. Until some years ago surgery was the only therapy. We have treated a large number of patients with Percutaneous Alcohol Sclerotherapy (PAS) and evaluated retrospectively the efficacy of this approach. Data on 21 patients with symptomatic simple hepatic cysts were reviewed retrospectively. Cysts had a mean diameter of 9 cm (range: 7-15 cm). PAS was always performed under local anesthesia and US guidance. 25% of the volume was replaced with 95% ethanol and then completely aspirated after 20-30 minutes. No complications or deaths occurred. In all patients symptoms disappeared after treatment. In 15 out of 21 cases there was no evidence of residual cyst on US, computed tomography (CT) or magnetic resonance (MRI). In 6 patients with shorter follow-up, cysts showed a mean reduction in diameter of 50%. The mean follow-up was 18 months (range 6-60 months). We conclude that PAS is easy with low risk for the patients and with good long-term results; it should therefore become the procedure of choice for simple hepatic cysts.

Adult↗
PubMed1994

[Adenocarcinoma in Barrett's esophagus: long-term results of curative resection].

Between 1980 and 1993, out of 635 patients presenting with an adenocarcinoma of the esophagogastric junction, 74 (11.7%) had a neoplasm arising from a columnar specialized epithelium lining the distal esophagus. Fifty of these patients (68%) underwent a curative (R0) resection. 36 patients (72%) were in stage 0, I or II, and the 5-year actuarial survival rate was 44%. The survival rate dropped to 13% when nodal metastases were present. We conclude that the long-lasting symptoms during the pre-neoplastic phase, and a closer endoscopic surveillance allow a early diagnosis of Barrett adenocarcinoma. Surgical therapy must be radical in these patients in order to improve prognosis.

Adenocarcinoma↗
PubMed1994

[Right adrenal adenoma: laparoscopic exeresis].

The authors report the case of a non functioning adrenal adenoma, incidentally diagnosed and excised through a laparoscopic approach. Indications to adrenalectomy for such a pathological condition and surgical technique are reviewed and discussed. In consideration of the relatively rare disease and of the scant literature on minimally-invasive approach to right adrenalectomy, it seemed worth reporting this case and the technical skills performed to ease this operation through laparoscopy.

Adenoma↗
PubMed1994

Antigenic outline of HHV-6 variants from infants with febrile illness.

The surface antigenic make-up of 10 HHV-6 isolates from cases of infantile disease was analyzed by immunofluorescence assay with 5 monoclonal antibodies (Mabs). Three Mabs were directed to glycoproteins (gps) expressed in cells infected with the HHV-6 variant A prototype GS, and 2 to gps expressed in cells infected with the HHV-6 variant B prototype Z29. Of the 10 viral isolates, all belonging to HHV-6 variant B, 9 showed a similar Mab reactivity, while 1, from a case of gastroenteric illness, differed widely from the others. The HHV-6 isolates studied also differed from the variant B prototype Z29 for the absence of reactivity to one of the Mabs. The choice of the HHV-6 new isolates as variant B prototypes is recommended.

Antibodies, Monoclonal↗
PubMed1994

Comparison between immunofluorescence and enzyme-linked-immunosorbent assay in the determination of serum HHV-6 IgG.

546 human sera from healthy subjects, subjects with cytomegalovirus or Epstein-Barr virus infection and from cordal blood were tested for the human herpesvirus-6 (HHV-6) IgG content in an enzyme-linked immunosorbent assay (ELISA) to verify results previously obtained with an immunofluorescence assay (IFA). The HHV-6 isolate CV, obtained from a child with exanthem subitum, employed as antigen in both tests, belonged to HHV-6 variant B. The ELISA results were similar to those obtained with IFA. 445/546 (81.5%) sera had the same type of reactivity with the two serological procedures. To establish whether different HHV-6 strains may give different serological results, 117 out of the 546 sera tested with IFA against CV infected cells were also tested against cells infected with the HHV-6 isolate U1102 belonging to variant A. All the sera showed a similar reactivity.

Adolescent↗
PubMed1993

Heat-stable and heat-labile thymidylate synthases B of Bacillus subtilis: comparison of the nucleotide and amino acid sequences.

Bacillus subtilis 168 is known to possess two thymidylate synthase (TSase; EC 2.1.1.45) genes: thyA and thyB. thyB encodes a thermosensitive TSase (inactivated at 46 degrees C) which, in wild-type cells, accounts for only 5-8% of the total cellular TSase activity. In order to investigate the thermal lability of TSaseB we have analyzed the thyB genes of B. subtilis 168 and of an unrelated strain B. subtilis ATCC6633, which is shown here to have a temperature-resistant TSaseB. This conclusion is supported by the frequency of appearance of spontaneous Thy- mutants at 37 degrees C and 46 degrees C, and by the analysis of clones containing the thyB genes from the two strains. The nucleotide sequences of these two thyB genes were compared.

Amino Acid Sequence↗
PubMed1993

Human herpesvirus 6 and multiple sclerosis: survey of anti-HHV-6 antibodies by immunofluorescence analysis and of viral sequences by polymerase chain reaction.

A possible involvement of human herpesvirus 6 (HHV-6) infection in the pathogenesis of multiple sclerosis (MS) was investigated. The immunofluorescence analysis of sera from 126 MS patients showed significantly higher anti-HHV-6 antibody titres in MS sera than in 500 normal controls. A polymerase chain reaction (PCR) assay of the peripheral blood mononuclear cell (PBMC) DNAs of 31 MS patients and 24 normal subjects was positive in one normal control and in one MS patient. The Southern blot analysis indicated an unexpectedly high level of viral sequences in the MS patient, but not in the control. Since viral sequences are rarely present in MS subjects, the high anti-HHV-6 antibody titres found in MS are likely to be related to immune impairment rather than reactivation of a latent infection.

Adolescent↗