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Biomedical subjects

M Colombo

Publications and source records attributed to M Colombo.

At least 91 records · Page 5Linked to original sources
PubMed1997

A randomized comparison of continuous versus interrupted mass closure of midline incisions in patients with gynecologic cancer.

OBJECTIVE: To address the incidence of deep wound dehiscence and incisional hernia formation with two types of mass closure after vertical midline laparotomy performed in patients with gynecologic cancer. METHODS: Continuous and interrupted mass closures were compared randomly in 632 patients. Both methods were performed with absorbable material. Of the 614 subjects who could be evaluated, 308 underwent a continuous, non-locking closure with looped polyglyconate suture, and 306 were closed with interrupted polyglycolic acid according to the Smead-Jones technique. RESULTS: Three (1%) subjects with the continuous closure and five (1.6%) with the interrupted closure had an abdominal wound infection (P = .50). One patient whose incision was closed with continuous suturing had a deep wound dehiscence (without evisceration). The follow-up period was 6 months to 3 years. No patient had evidence of chronic sinus drainage. Thirty-two (10.4%) of the patients who had the continuous closure and 45 (14.7%) of those who were closed with the interrupted method had evidence of incisional hernia (P = .14). No hernia developed in any patient with a wound infection. Four (1.3%) hernias after the continuous closure and eight (2.6%) after the interrupted closure required surgical repair because of patient discomfort (P = .38). CONCLUSION: The interrupted closure was not superior to the continuous closure for short- and long-term wound security. The continuous method was preferable because it was more cost-efficient and faster.

Adult↗
PubMed1997

Diversity of antinuclear antibody responses in hepatocellular carcinoma.

BACKGROUND/AIMS: The development of antinuclear antibodies (ANA) in malignancies has been described but its mechanism is still not understood. The aim of this study was to examine ANA specificities in hepatocellular carcinoma to further understand autoimmunity in cancer. METHODS: Two hundred and four hepatocellular carcinoma patients were compared with 68 chronic hepatitis C, with 126 chronic hepatitis B and with 30 alcoholic liver cirrhosis patients, as well as with 87 healthy donors. Indirect immunofluorescence, immunoblotting, and immunoprecipitation were used to study ANA reactivities. RESULTS: Hepatocellular carcinoma had a significantly higher frequency of ANA using HEp-2 cells as substrate (31%) than chronic hepatitis C (10%), chronic hepatitis B (9.5%), alcoholic liver cirrhosis (10%) or healthy donors (4.5%). A great diversity of ANA specificities was found in hepatocellular carcinoma. Three hepatoma sera had antibodies that co-localized with non-snRNP splicing factor SC35, suggesting that the antigenic targets might be involved in mRNA splicing. We identified antibodies to two known nuclear autoantigens: fibrillarin and p330d/CENP-F. These autoantigens are involved in the 5' processing of precursor ribosomal RNA transcripts and in mitotic functions, respectively. CONCLUSIONS: Diversity was found in the autoantibody specificity, in contrast to the specific subsets of autoantibodies seen in several systemic rheumatic autoimmune diseases. Our data suggest that immune response in hepatocellular carcinoma targets important proteins involved in cellular biosynthetic or proliferative functions.

Adult↗
PubMed1997

Choriocarcinoma coexistent with intrauterine pregnancy: two additional cases and a review of the literature.

Choriocarcinoma coexistent with normal intrauterine pregnancy is rare and poses questions about its origin. Although the development from trophoblastic remnants of previous pregnancies can not be excluded in some cases, the findings of incidental macro- and microscopic foci of choriocarcinoma in apparently normal placentas show the possible transformation of normal trophoblast into choriocarcinoma during an otherwise normal pregnancy. The diagnosis and management of choriocarcinoma coexistent with intrauterine pregnancy have changed dramatically over the decades but the survival rates are still unsatisfactory. In this review, we summarize some of the most common features of this disease.

Journal Article↗
PubMed1997

The effects of hippocampal and area parahippocampalis lesions in pigeons: II. Concurrent discrimination and spatial memory.

Two experiments were conducted to examine the effects of bilateral hippocampus (Hp) and area parahippocampalis (APH) lesions in pigeons on the acquisition of a visual and spatial task. In Experiment 1, pigeons were trained on three successive six-pair concurrent discrimination tasks, each using a novel set of stimuli. There was no difference between control unoperated pigeons and Hp-APH pigeons in terms of the number of sessions required to learn either the first, second, or third concurrent discrimination task. In Experiment 2, the same pigeons were trained on an open-field spatial task similar in many ways to the radial-arm maze task used with rats. In contrast to the absence of impairments on the visual concurrent discrimination task, pigeons with Hp-APH lesions were severely impaired on the acquisition of the spatial task. These findings support the view that the Hp-APH in pigeons is important for the processing of spatial, rather than visual information.

Animals↗
PubMed1997

The effects of hippocampal and area parahippocampalis lesions in pigeons: I. Delayed matching to sample.

Four experiments were conducted to determine the effects of bilateral damage to the hippocampus and area parahippocampalis (Hp-APH) on visual memory in pigeons using the delayed matching-to-sample (DMS) procedure. In Experiment 1, we generated visual retention gradients with delays of 0, 1.5, 3, 6, and 12 sec both preoperatively and postoperatively in three pigeons with considerable preoperative visual DMS experience. Bilateral Hp-APH lesions had no effect whatsoever on visual retention. In Experiment 2, we examined the effects of Hp-APH lesions on both the acquisition of a visual DMS task with a 0-sec delay, and the subsequent retention performance with delays of 0, 3, 6, 12, and 24 sec. There was no difference between unoperated control pigeons and Hp-APH pigeons either in terms of the number of sessions required to learn the visual DMS task or in terms of their subsequent visual retention performance levels. In Experiments 3 and 4, we examined whether Hp-APH pigeons might be more sensitive than control pigeons to the effects of proactive interference (by reducing the duration of the intertrial interval) and retroactive interference (by introducing delay-interval illumination). Although reducing the duration of the intertrial interval and increasing the level of delay-interval illumination both resulted in lower performance levels on the visual DMS task, there was no indication that the Hp-APH pigeons were any more affected by the changes in interference levels than were unoperated control pigeons. These findings support the view that the Hp-APH in pigeons plays little role in the processing and retention of purely visual information.

Animals↗
PubMed1997

Treatment of hepatocellular carcinoma.

Treatment of patients with hepatocellular carcinoma (HCC) is largely influenced by local resources and the clinical stage of the disease. Hepatic resection is the treatment of choice for patients with HCC and normal liver. Tumour size and number, and liver status are common guidelines for choosing treatment in patients with cirrhosis. Hepatic resection and liver transplantation offered the best chances of cure in patients with a single small tumour. The 3-year survival of these patients was definitively better than that of historical controls. In the setting of patients with well-preserved liver function, a controlled study comparing the cost-efficacy of resection and transplantation is deemed necessary by many, but it is hardly feasible for both ethical and practical considerations. One major drawback of surgery in patients with a small tumour is early tumour spread to regional lymph-nodes, which favours early tumour recurrence after operation. Patients with more advanced tumour disease were rarely eligible for surgery and had dismal prognoses. For those with small tumours who were not eligible for surgery, percutaneous ethanol injection appeared to be a cost-saving and effective treatment modality. Arterial embolization is the only recommendable palliative treatment of patients with large tumours and poor hepatic function.

Carcinoma, Hepatocellular↗
PubMed1996

The effects of superior temporal cortex lesions on the processing and retention of auditory information in monkeys (Cebus apella).

Three monkeys with extensive preoperative training on visual and auditory memory tasks (delayed matching-to-sample), an auditory pattern-discrimination task, and a visual serial-order task, received bilateral lesions of the superior temporal (ST) cortex in two stages, with testing after each lesion. Unilateral ST cortex lesions resulted in only moderate auditory memory impairments, whereas bilateral ST cortex lesions resulted in severe auditory memory impairments. The bilateral ST cortex lesions also resulted in severe impairments in the ability to relearn the auditory pattern-discrimination task. In contrast to the auditory impairments, neither unilateral nor bilateral ST cortex lesions had any effect whatsoever on either visual memory or visual serial-order behavior. These findings indicate that the ST cortex plays a role in auditory processing and retention similar to that played by the inferior temporal cortex for visual processing and retention.

Acoustic Stimulation↗
PubMed1996

A prospective, randomized trial comparing lymphoblastoid to recombinant interferon alfa 2a as therapy for chronic hepatitis C.

To compare the long-term effectiveness and tolerability of lymphoblastoid interferon (IFN-alphaN1) and recombinant interferon alfa 2a (IFN-alpha2a) in patients with chronic hepatitis caused by hepatitis C virus (HCV), 234 consecutive patients with HCV-related chronic hepatitis were randomized prospectively to receive titrated doses (starting dose = 6 million units [MU]) of IFN-alpha2a (n = 118) or IFN-alphaN1 (n = 116) for 12 months. HCV RNA was detected by reverse-transcription polymerase chain reaction (RT-PCR), quantified by branched-DNA (bDNA) assay, and genotyped by reverse hybridization assay. Thirty-one patients in the IFN-alpha2a group and 28 in the IFN-alphaN1 group (total, 59 [25%] had normal transaminases and undetectable HCV RNA by RT-PCR after 12 months of therapy, but only 19 in the first group and 20 in the second group (total, 39 [17%]) had biochemical and virological responses 12 months after treatment was discontinued. The two treatment groups differed in terms of prevalence of major drug-related adverse reactions (23% vs. 37%, P = .025). The mean total dose per patient was similar for the two groups, i.e., 502 MU IFN-alpha2a vs. 496 MU IFN-alphaN1, and the cost of each sustained response was $31,800 and $32,440, respectively. By multivariate analysis, pretreatment viremia higher than 0.2 MEq/mL and infection with genotype 1 were independently associated to treatment failure. The outcome of treatment in chronic hepatitis C patients was not improved by the administration of high cumulative doses of lymphoblastoid IFN.

Female↗
PubMed1996

Prevention of postoperative urinary stress incontinence after surgery for genitourinary prolapse.

OBJECTIVE: To compare cystopexy alone versus cystopexy with posterior pubourethral ligaments plication for the occurrence of postoperative stress incontinence after prolapse surgery, and to compare the two surgical series in terms of complications and urodynamic effects. METHODS: One hundred two continent patients randomly underwent cystopexy alone (N = 52) or cystopexy with posterior pubourethral ligaments plication (N = 50). All had a urethrocystocele grade 2 or greater and a negative stress test with the prolapse repositioned. A full urodynamic investigation was repeated 6 months after surgery. RESULTS: Twelve (23%) and 14 (28%) patients (P = .73) required intermittent self-catheterization for 11.1 +/- 5.1 and 16.5 +/- 11.1 days, respectively (cystopexy alone versus cystopexy with posterior pubourethral ligaments plication, P = .002). Long-lasting difficulties in voiding were present in zero and five (10%) patients (P = .02). One subject receiving posterior pubourethral ligaments plication underwent urethral dilation for complete urinary retention. At 1 year follow-up, four patients (8%) in each series developed postoperative stress incontinence (P = .62). Symptomatic detrusor instability complicated the postoperative course in one patient (2%) of each group. CONCLUSION: Cystopexy alone implied lower morbidity in terms of resumption of spontaneous voiding and long-lasting difficulties in voiding. The procedure could be recommended as an effective and safe treatment for continent patients with severe urethrocystocele. Additional plication of the posterior pubourethral ligaments did not seem superior to cystopexy alone in preventing the postoperative occurrence of stress incontinence.

Aged↗
PubMed1996

Memory procedures, performance and processes in pigeons.

Short-term memory in pigeons is studied in the delayed matching-to-sample procedure where information is forgotten over short periods of time. Performance in this task reflects the separate influences of attention to the sample stimuli and memorial processes and is determined by a range of procedural variables. Forgetting functions can be obtained by varying the duration of the retention interval and can be quantified in terms of the parameters of a fitted function, such as the negative exponential. These parameters provide measures of initial discriminability and rate of forgetting and are sensitive to the effects of drugs known to influence the cholinergic, GABA and dopaminergic systems. The results of behavioral pharmacological studies suggest that the effects of a variety of drugs on initial discriminability and rate of forgetting are quite similar for pigeons and monkeys. We conclude that pigeons serve as an effective model to examine the effects of agonist and antagonist drugs on memory.

Animals↗
PubMed1996

A randomized comparison of Burch colposuspension and abdominal paravaginal defect repair for female stress urinary incontinence.

OBJECTIVE: Our aim was to compare Burch colposuspension and paravaginal repair for success rates, complications, and urodynamic effects when the procedures are used in the treatment of stress urinary incontinence. STUDY DESIGN: Thirty-six patients were enrolled. A full urodynamic evaluation was repeated 6 months postoperatively. RESULTS: Twelve (67%) and 17 (94%) subjects (Burch colposuspension vs paravaginal repair) voided spontaneously before discharge (p = 0.04). One patient receiving the Burch procedure underwent urethral dilation for urinary retention. Follow-up was for 1 to 3 years. Differences in subjective and objective cure rates favored the Burch colposuspension over the paravaginal repair: 100% versus 72% (p = 0.02) and 100% versus 61% (p = 0.004), respectively. The paravaginal repair did not produce significant modifications in profilometry. Postoperatively, cotton swab tests had negative results in all patients with the Burch operation and in 33% of those with the paravaginal repair (p = 0.01). CONCLUSION: Paravaginal repair is not recommended for the treatment of stress incontinence, although it was accompanied by a more immediate resumption of voiding.

Adult↗
PubMed1996

Epidemiological, clinical and therapeutic associations of hepatitis C types in western European patients.

BACKGROUND/AIMS: Different variants of hepatitis C virus might show different susceptibility to interferon alpha treatment, but it is important to understand whether this difference in sensitivity reflects an association with other factors, such as cirrhosis or age. METHODS: We have used an enzyme-linked immunosorbent hepatitis C virus typing assay based upon the detection of antibody in patient's era to type-specific NS-4 antigens to investigate the effect of hepatitis C virus type in 610 patients with chronic hepatitis C virus infection. The influence of viral types and their interdependency with host factors were separately analyzed to establish which factors executed an independent effect on the probability of sustained response. RESULTS: There was a marked difference in the distribution of hepatitis C virus types with age: infection with type 3 was more common in younger patients. The distribution of hepatitis C virus type with age is accounted for by differences in risk-factors for infection in different age groups. The frequency of cirrhosis increased markedly with age. Even after standardization for age, center and the presence of cirrhosis, viral type was strongly related to the outcome of infection. CONCLUSIONS: Our data suggest that enzyme-linked immunosorbent hepatitis C virus typing could assist in patient selection for interferon treatment to improve sustained response rates. Together with measurement of viral load, hepatitis C virus typing may serve to indicate the probability of response in patients with chronic hepatitis C, and to elucidate antiviral mechanisms in the disease. The serotyping assay provides a relatively inexpensive screening method to determine the infecting hepatitis C virus type, which could facilitate therapeutic decisions and strategies in patients with chronic hepatitis C.

Adolescent↗
PubMed1996

Increased detection of antibody to hepatitis C virus in renal transplant patients by third-generation assays.

To assess the sensitivity and specificity of third-generation assays for antibody to hepatitis C virus (anti-HCV), sera from 244 renal transplant patients (113 positive for anti-HCV enzyme-linked immunosorbent assay [ELISA]-2) were studied. Hepatitis C virus RNA was detected by a reverse-transcripted nested polymerase chain reaction. Antibody to HCV was detected by ELISA-3 in 108 (96%) ELISA-2-positive samples. Five (4%) ELISA-2-positive sera were negative by both ELISA-3 and polymerase chain reaction. In the anti-HCV-negative group, six (5%) additional cases were ELISA-3-positive; three of these were confirmed by recombinant immunoblot assay-3 (RIBA-3) and polymerase chain reaction. Recombinant immunoblot assay-3 was used to resolve 82 RIBA-2-indeterminate and three RIBA-2-negative sera. Using RIBA-3, 49 (60%) RIBA-2-indeterminate samples were positive, five (6%) ELISA-3-negative samples were negative, and 28 (34%) were remained indeterminate. Recombinant immunoblot assay-2-negative samples were indeterminate with RIBA-3. Hepatitis C virus RNA was detected in all RIBA-3-positive and 58% of the RIBA-3-indeterminate samples. Third-generation assays for anti-HCV are more sensitive and specific than second-generation assays in renal transplant patients.

Adolescent↗
PubMed1996

The natural history of hepatitis C.

The natural history of hepatitis C is complex and still poorly known. Hepatitis C virus (HCV) replication can be detected very soon after exposure and, at least in the transfusional setting, it persists indefinitely in up to 90% of the cases. While liver damage during the acute phase of hepatitis is almost invariably mild (fulminant cases are exceptions), chronic sequelae of HCV infection may be severe in the long run. Chronic hepatitis C, in fact, is a long-lasting indolent process which leads to cirrhosis in approximately 20% of all infected patients. Hepatocellular carcinoma is a well-recognized complication of old infections, as are a number of extrahepatic manifestations, including type II cryoglobulinaemia. The determinants of the severity of the liver disease are still unclear. However, the risk of cirrhosis seems to be greater for patients with old infections, those infected with the genotype 1b and those with associated conditions. The latter are a heterogeneous and increasing group of 'problem' patients, including patients who are co-infected with the human immunodeficiency virus (HIV1), or who are being treated with cytotoxic or immunomodulating drugs. Data suggest that the natural history of hepatitis C is altered in patients with associated conditions, and this might have an impact on strategies of patient management and treatment.

Carcinoma, Hepatocellular↗
PubMed1996

Relevance of lymphoproliferative disorders and of anti-C1 inhibitor autoantibodies in acquired angio-oedema.

We looked for autoantibodies to C1 inhibitor (C1-INH) and evaluated the relationship of their presence to the associated lymphoproliferative diseases and to the cleaved form of C1-INH in 13 patients with acquired C1-INH deficiency (acquired angio-oedema (AAE)). At the time of manifestation of angio-oedema symptoms or within a few years the following diseases were diagnosed: liver angioma (n = 1), M-components (n = 7, one of whom also had echinococcal liver cysts), breast cancer (n = 1), chronic lymphocytic leukaemia (CLL; n = 1); three patients had no associated disease. Anti-C1-INH autoantibodies, measured both as immunoglobulin binding to C1-INH immobilized onto microtitre plates (ELISA) and as plasma inhibitory activity of C1-INH function, were found in 12 patients. Binding of C1-INH to paraproteins, transferred to Immobilon after agarose gel electrophoresis, was detectable in five of seven M-components associated with AAE. Immunoblotting analysis of SDS-PAGE-separated plasma demonstrated that C1-INH circulated in the cleaved 96-kD form in the 12 patients with autoantibodies, but not in the one without. In conclusion, the large majority of our patients have autoantibodies to C1-INH. Circulating autoantibodies are necessary for the generation of cleaved C1-INH. The paraproteins associated with AAE are frequently autoantibodies to C1-INH and thus account for its consumption.

Adult↗
PubMed1996

Detection of abnormal intrauterine vascularization by color Doppler imaging: a possible additional aid for the follow up of patients with gestational trophoblastic tumors.

Uterine morphology assessed by transvaginal ultrasound and the hemodynamics of intratumoral vessels assessed by color Doppler ultrasound were prospectively correlated with the clinical outcome of 25 patients with trophoblastic tumors. Twenty patients were followed without treatment (observation group) and 16 achieved complete local resolution. The four subjects with local persistence were combined with five patients referred from other institutions and received chemotherapy (treatment group). In the observation group both techniques had 100% accuracy in predicting local resolution or local persistence. Persistence was predicted 1-3 weeks before the increase of beta-human chorionic gonadotropin (beta-hCG) levels, whereas resolution was observed up to 8 weeks before the disappearance of beta-hCG. In one patient normal uterine morphology and vascularization in the presence of elevated hCG levels was associated with extrauterine spread. In the treatment group, normal uterine ultrasound morphology and negative color Doppler results had 100% negative predictive value. False-positive results were observed in two cases. We conclude that ultrasound evidence of abnormal uterine morphology or persistent vascularization on color Doppler examination with persistent hCG levels is indicative of local persistence. Normal uterine morphology with negative color Doppler results may be associated with extrauterine spread.

Blood Flow Velocity↗