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Biomedical subjects

A Rey

Publications and source records attributed to A Rey.

At least 127 records · Page 7Linked to original sources
PubMed1995

c-erbB2 gene amplification and protein expression in ovarian epithelial tumors: evaluation of their respective prognostic significance by multivariate analysis.

c-erbB2 gene amplification or over-expression has been reported in ovarian cancer, but their prognostic value remains conflicting. To investigate the respective prognostic significance of c-erbB2 gene amplification and protein over-expression, tumor samples were obtained from 65 patients with ovarian adenocarcinoma (9 FIGO stage I, 7 stage II, 38 stage III and II stage IV) followed up for a median period of 71 months. c-erbB2 gene amplification (> or = 2.5 a.u.) was detected in 9/65 (14%) adenocarcinomas and in none of 5 benign and 8 borderline ovarian epithelial tumors also analyzed. Specimens from 52 of the 65 adenocarcinomas were available for immunohistochemical analysis. c-erbB2 protein expression was observed in 23/52 (44%) adenocarcinomas. No correlation was found between c-erbB2 gene copy number and protein expression. There was no correlation of c-erbB2 gene copy number or protein expression with any of the clinico-pathological factors analyzed (i.e., FIGO stage, histological type, histological grade and residual tumor). On univariate analysis, c-erbB2 gene amplification was associated with poorer survival (p = 0.04). However, in the multivariate analysis of clinico-pathological factors and c-erbB2 gene copy number, c-erbB2 gene amplification did not retain any independent prognostic significance (p = 0.19). No significant survival difference was found between patients with and without c-erbB2 protein over-expression in univariate or multivariate analyses. Therefore, neither c-erbB2 gene amplification nor c-erbB2 protein over-expression appears to be a significant prognostic marker in patients with ovarian carcinoma.

Adenocarcinoma↗
PubMed1995

[Pituitary apoplexy].

Pituitary apoplexy results from necrosis or haemorrhage of a pituitary adenoma. This rare complication occurs in 2 to 10% of operated adenomas. The acute form results from massive intrapituitary bleeding leading to violent headache, meningeal signs, impaired conscience and ophthalmology signs, basically bilateral blindness. Associated signs are frequent including paralysis of the oculomotor nerves, epilepsy seizure, hemiplegia. Diabetes insipidis is exceptional. In less acute forms, the sudden nature of the headache and ophthalmology signs can suggest diagnosis. Standard X-ray reveals destruction of the sella turcica. Computed tomography shows either a haematoma or a cystic cavity in the pituitary gland which must be perfectly described together with the integrity of the bone structures due to the risk of lysis. Magnetic resonance imaging is an essential technique which can be used to describe the volume and suprasellar extension of the tumour, its texture, possible compression of adjacent structures and determine the age of the haemorrhage. This imaging technique can also isolate rare optochiasmatic apoplexia requiring intracranial evacuation. Emergency surgery is mandatory for most all authors. Rhinal-septal decompression is usually used, but the intracranial route may be preferred for very large suprasellar tumours. Medical treatment alone may be successful for small prolactin adenomas. Outcome depends on the time lapse to decompression. Optic nerve recovery is usually possible if the delay is less than 7 days. Cranial nerve recovery is less dependent on the time interval. In all cases hormone substitution is required.

Adenoma↗
PubMed1995

Colorectal carcinomas: diagnosis and preoperative staging by hydrocolonic sonography.

BACKGROUND: The aim of this study was to determine the sensitivity, specificity, and predictive value of hydrocolonic sonography (HS) in the detection and preoperative staging of colonic carcinomas. METHODS: One hundred four patients referred to our department for colorectal disease were examined in a prospective study with conventional transabdominal sonography followed by HS and other well-established means for detection of colorectal cancer. In all diagnosed colorectal carcinomas, surgical resection and histologic examination were carried out, and the histologically confirmed tumor stage was then compared with the stage predicted by HS. RESULTS: HS staged and made a correct diagnosis of carcinoma in 39 of 40 patients, with a sensitivity of 97.5% and a specificity of 98%. Positive predictability was 97.5% and negative predictability 98%. In the evaluation of cancer depth invasion, HS staging was correct in all but one case, in which a T3 tumor was incorrectly judged to be T2. In the assessment of the presence or absence of peritumor metastatic lymph nodes, HS had a sensitivity of 50% and a specificity of 100%. CONCLUSIONS: HS allows the diagnosis and preoperative staging of colorectal carcinomas with high sensitivity, specificity, and predictive value. We highly recommend its preoperative use because of its definitive influence on surgical approach.

Adult↗
PubMed1995

Transbronchial fine needle aspiration in clinical practice.

We review our experience of transbronchial fine needle aspiration (TBFNA) over a 3-year period. A total of 112 TBFNAs were performed on 95 patients. Four aspirates were from peripheral lung lesions, 20 from non-ulcerated submucosal infiltrative lesions, 19 from mediastinal abnormalities close to the tracheobronchial tree, and the remaining 69 were for staging of bronchogenic carcinoma with apparent mediastinal lymph node spread, evaluated by chest computed tomography (CT). In the 20 submucosal lesions TBFNA reached a sensitivity of 82.3%, providing the only evidence of a malignant process in five cases. With respect to the 19 mediastinal lesions arising in close proximity to the central airways, TBFNA permitted a diagnosis in cases that would otherwise have required more invasive procedures, although the diagnostic sensitivity of the technique in this group of patients was poor (26%). In the mediastinal staging group, the sensitivity was 76.9%, with no false positive results. Complete sensitivity of TBFNA for the detection of disease was 65.8%. We conclude that TBFNA is a reliable and low risk procedure.

Adolescent↗
PubMed1995

[Problems which arise when testing the equivalence of 2 survival distributions].

Clinicians' interest in equivalence trials has been increasing for many years. In cancer research we are more often concerned with survival or event free survival (EFS). The usual logrank test has to be modified to test whether the true value r of the relative risk is at least equal to a limit value rL. An equivalence trial of post-operative therapy was carried out in children with stage II nephroblastomas without lymph node involvement, and serves as an illustration of some problems, discussed here, which arise in such design: ethical questions when defining the equivalence region, the choice of a one sided or a two sided formulation, the required number of patients or the power of the comparison. A formula is given in order to allow calculation for the required number of patients to ensure a given power when the treatment effects are the same. Other problems are also encountered when analyzing the observed results as the number of events which is evidently low in a de-escalation trial, may be reduced due to a stopping rule. We also discuss about the possibility to use event free survival as a surrogate of overall survival, and about the difficulties encountered when interpreting the results in terms of significance level.

Disease-Free Survival↗
PubMed1995

[Surgery for meningioma of the posterior skull base. 135 cases. Choice of approach and results].

One hundred and thirty-five patients with posterior skull base meningiomas were seen and treated by a neurosurgical-neurotological team over the last 12 years. Ten tumors were "true" clival meningiomas and 125 were posterior petrous meningiomas: 25 were located anterior to the internal auditory meatus (IAM) (zone A); 29 were located around the IAM (zone M) and 18 were posterior to the IAM (zone P). 53 tumors had a larger zone of implantation and are accordingly called AM (31 cases), MP (15 cases), AMP (7 cases). The choice of routes was guided by a radiological anatomy classification system (17). Transpetrous approaches, alone or in combination with subtemporal transtentorial or retrosigmoid approaches were the surgical routes of choice for posterior petrous meningiomas, making it possible to reach the tumoral osteodural implantation, reduce the tumoral mass and perform a subarachnoidal dissection of the tumor poles. A retrolabyrinthine (RL) approach allows access to zone P and a translabyrinthine approach to zone MP. Zones A, M and P can be reached via the anterior extended translabyrinthine (AETL) approach. Anterolateral transclival approaches with apex petrectomy were used to reach the clival meningiomas with a wide implantation zone. Standard microsurgical techniques were used in 32 cases and 103 procedures included the use of a microscope-guided laser. Complete tumor removal was accomplished in 88% of cases (120/135). Overall mortality was 3.7% (2 cases at 30 days and 3 cases between 31 days and 1 year).

Aged↗
PubMed1995

[Subdural empyema. Apropos of 17 cases].

Seventeen patients with subdural empyema were treated from 1985 to 1993. These included 13 males and 4 females with 11 patients aged between 12 and 30 years old. Sinusitis was found to be the primary source of infection in 16 cases. The clinical presentation was classic and the preoperative diagnosis was established on the first CT in 12 cases. In the remaining cases a second or third CT was necessary to demonstrate the empyema, 24 to 48 hours later. Surgical management was first made by burr holes with a small craniectomy in 15 cases. A large craniotomy was performed in 2 patients. Soft catheter drainage was carried out in 6 cases, 9 patients received surgical treatment once (3) or twice (6). Two patients, operated on while in a coma (stage IV of Bannister scale) died and one patient survived with severe disability (operated at stage III). The others (14) made a good recovery (6 in grade A and 8 in grade B of Mauser). These results were compared with those in the literature and we concluded that the mean factor of prognosis is the level of consciousness at the time of initial treatment. In most of the cases, burr holes or a small craniotomy, carried out on the basis of CT or MRI data, are the easiest and most effective method of surgical treatment.

Adolescent↗
PubMed1994

Treatment of intracranial ependymomas of children: review of a 15-year experience.

PURPOSE: There are still major controversies in the optimal management of children with intracranial ependymomas. To assess the impact of tumor site, histology, and treatment, the outcome of children treated at the Institut Gustave Roussy was reviewed retrospectively. METHODS AND MATERIALS: Between 1975 and 1989, 80 children aged 4 months to 15.8 years were seen at the Institut Gustave Roussy for postoperative management of an intracranial ependymoma. Location of tumor was infratentorial in 63 cases and supratentorial in 17. Surgical treatment consisted of complete resection in 38, incomplete resection in 38 and biopsy only in 4. Postoperative irradiation was done in 65 patients and chemotherapy in 33. Surviving patients have been followed from 12-197 months with a median of 54 months. RESULTS: The 5-year actuarial survival and event-free survival are 56% and 38%, respectively. Thirty-four patients relapsed from 3-72 months after diagnosis (median 25 months). In 20 patients, the only site of failure was the original tumor site. Three patients failed locally and at distance, while 10 others failed only at distance. Survival at 5 years was significantly better for patients who had complete resection of the tumor (75% vs. 41%, p = 0.001) and for those who received radiation therapy (63% vs. 23%, p = 0.003). Event-free survival at 5 years was superior in patients with complete resection of the tumor (51% vs. 26%, p = 0.002) and in patients who received radiation therapy (45% vs. 0%, p < 0.001). Sex and tumor site had no impact on survival or event-free survival. There was no difference in survival, event-free survival, or pattern of failure between patients treated with local field, whole brain or craniospinal irradiation, while severe longterm sequelae were noted predominantly in the latter two groups. CONCLUSION: Considering that failures were predominantly local and that there was no apparent benefit from prophylactic irradiation, we recommend local field irradiation with doses above 50.0 Gy for all children with intracranial ependymomas, without meningeal dissemination at diagnosis. Special considerations are necessary for children < 3 years of age.

Adolescent↗
PubMed1994

Value of postchemotherapy bioptical verification of complete clinical remission in previously incompletely resected (stage I and II pT3) malignant mesenchymal tumors in children: International Society of Pediatric Oncology 1984 Malignant Mesenchymal Tumors Study.

Bioptical verification of complete clinical remission achieved with postoperative chemotherapy in 140 pediatric patients with nonradically resected stages I and II nonparameningeal malignant mesenchymal tumors was evaluated. Tumor histology was rhabdomyosarcoma in 92 and nonrhabdomyosarcoma in 48 patients. All were included in the International Society of Pediatric Oncology "1984 Malignant Mesenchymal Tumors Study." Treatment given after nonradical surgery and before the biopsy consisted of 3 to 6 IVA courses (ifosfamide, vincristine, actinomycin D). Complete clinical remission (no tumor at physical examination, X-rays, sonography, computed tomography, scintigraphy) was bioptically confirmed in 52 rhabdomyosarcoma and 23 nonrhabdomyosarcoma cases, whereas in all the remaining patients (39 rhabdomyosarcoma and 22 nonrhabdomyosarcoma) complete clinical remission was not bioptically verified. Forty-eight-month local relapse rates were 51% in bioptically confirmed and 48% in nonbiopsied rhabdomyosarcoma patients. In nonrhabdomyosarcoma cases, relapse rates were 25% and 14%, respectively. In 4 cases, bioptical specimens contained tumor cells. In spite of aggressive treatment, only 1 is actually in remission. The total 48-month relapse rate (biopsied and nonbiopsied) was significantly higher in rhabdomyosarcoma patients (50%) than in nonrhabdomyosarcoma patients (26%). The value of bioptical verification of complete clinical remission seems to be limited in our series, when known that relapse rate in bioptically confirmed complete remission cases remained high and the outcome in rare "positive biopsy patients" was poor.

Adolescent↗
PubMed1994

Usefulness of microscopic examination of intracellular organisms in lavage fluid in ventilator-associated pneumonia.

STUDY OBJECTIVE: To assess the usefulness of quantification of bronchoalveolar lavage (BAL) cells containing intracellular organisms (ICO) in the diagnosis of ventilator-associated pneumonia. DESIGN: The reliability of cytologic analysis in comparison with the protected specimen brush (PSB) and BAL quantitative cultures has been assessed in a prospective study. SETTING: An intensive care unit of a tertiary-referral teaching hospital. PATIENTS: A total of 33 ventilated patients with suspected pneumonia based on clinical grounds and radiographic findings. INTERVENTIONS: All patients underwent fiberoptic bronchoscopy within the first 24 h after clinical suspicion of pneumonia. Specimens were obtained by PSB and BAL and were processed for quantitative cultures using standard methods. Two 0.5-ml samples of resuspended original BAL fluid were centrifuged and stained with Gram and modified May-Grünwald-Giemsa for differential cell counts and percentage of cells with ICO. RESULTS: Pneumonia was the final diagnosis in 16 (49 percent) of the 33 patients. In 14 (42 percent) patients, pneumonia was excluded and in the remaining 3 the diagnosis was uncertain. Twelve of the 16 patients with pneumonia had their conditions diagnosed by PSB, 14 by BAL, and 10 by quantification of ICO. Only one patient's condition was diagnosed exclusively by cytologic examination. There were no false-positive results with any of the diagnostic techniques. CONCLUSIONS: Microscopic identification of ICO in cells recovered by BAL allows early and accurate diagnosis of pneumonia in mechanically ventilated patients. However, the sensitivity of this technique is lower than with either PSB or BAL.

Adolescent↗
PubMed1994

[Surgical approach to petroclival meningioma. Value of translabyrinthine approach extended to the petrous apex].

Petro-clival meningiomas are rare tumors. Because of their deep location in the posterior fossa, many surgical approaches have been proposed, generally with severe post-operative morbidity and mortality. Thirty-six meningiomas of the petrous apex (34 posterior surface of petrous bone meningiomas, 2 clivus meningiomas) were operated, via a trans petrosal approach, from 1983 to 1993. In 14 cases, the trans-labyrinthine (TL) approach, extended by drilling the bone above the internal auditory canal (IAC) was performed (39%). In 18 cases the TL approach was extended in a subtemporal, transtentorial approach (50%). In one case (2.5%), after rerouting the facial nerve posteriorly, the TL approach was extended anteriorly in a transcochlear approach. The retro-sigmoïd approach was performed in one case (2.5%). The extended middle fossa approach was performed in two cases of clivus meningiomas (5%). Total excision was obtained in 27 cases (75%). By using the Laser, quality of resection is increased. Most complications and morbidity were encountered with tumors extending towards the cavernous sinus. Extended translabyrinthine approach allows total excision in most of cases of petro-clival meningiomas. For clivus tumors or tumors invading the cavernous sinus, the extended middle fossa approach and subtotal petrosectomy are proposed respectively.

Adult↗
PubMed1993

Overall treatment time in advanced cervical carcinomas: a critical parameter in treatment outcome.

PURPOSE: To search for possible influence of overall treatment time on the clinical outcome of advanced cervical carcinomas treated with radiation alone. METHODS AND MATERIALS: Three hundred and eighty-six patients with Stage IIB and III cervical carcinomas treated with external radiation and intracavitary curietherapy between 1973 and 1983 were entered in the study. A multivariate analysis was carried out on data concerning these patients to determine whether overall treatment time was a prognostic factor. RESULTS: Overall treatment time and blood transfusions during treatment were the two most highly significant factors in the multivariate analysis. Loss of local control and overall survival, when treatment exceeded 52 days, was approximately 1% per day in both cases. CONCLUSION: These results suggest that overall treatment time might be a highly significant prognostic factor in the treatment outcome of advanced cervical carcinomas. Prospective randomized studies are strongly warranted to confirm this hypothesis.

Adult↗
PubMed1993

A method for predicting protein structure from sequence.

BACKGROUND: The ability to predict the native conformation of a globular protein from its amino-acid sequence is an important unsolved problem of molecular biology. We have previously reported a method in which reduced representations of proteins are folded on a lattice by Monte Carlo simulation, using statistically-derived potentials. When applied to sequences designed to fold into four-helix bundles, this method generated predicted conformations closely resembling the real ones. RESULTS: We now report a hierarchical approach to protein-structure prediction, in which two cycles of the above-mentioned lattice method (the second on a finer lattice) are followed by a full-atom molecular dynamics simulation. The end product of the simulations is thus a full-atom representation of the predicted structure. The application of this procedure to the 60 residue, B domain of staphylococcal protein A predicts a three-helix bundle with a backbone root mean square (rms) deviation of 2.25-3 A from the experimentally determined structure. Further application to a designed, 120 residue monomeric protein, mROP, based on the dimeric ROP protein of Escherichia coli, predicts a left turning, four-helix bundle native state. Although the ultimate assessment of the quality of this prediction awaits the experimental determination of the mROP structure, a comparison of this structure with the set of equivalent residues in the ROP dime- crystal structure indicates that they have a rms deviation of approximately 3.6-4.2 A. CONCLUSION: Thus, for a set of helical proteins that have simple native topologies, the native folds of the proteins can be predicted with reasonable accuracy from their sequences alone. Our approach suggest a direction for future work addressing the protein-folding problem.

Journal Article↗
PubMed1993

Computer modeling and folding of four-helix bundles.

In the context of simplified models of globular proteins, the requirements for the unique folding to a four-helix bundle have been addressed through a new Monte Carlo procedure. In particular, the relative importance of secondary versus tertiary interactions in determining the nature of the folded structure is examined. Various cases spanning the extremes where tertiary interactions completely dominant to that where tertiary interactions are negligible have been explored. Not surprisingly, the folding to unique four-helix bundles is found to depend on an adequate balance of the secondary and tertiary interactions. Moreover, because the simplified model is composed of spheres representing alpha-carbons and side chains, the geometry of the latter being based on small real amino acids, the role played by the side chains, and the problems associated with packing and hard-core repulsions, are considered. Also, possible folding intermediates and their relationship with the experimentally observed molten globule state are explored. From these studies, a general set of rules is extracted which should aid in the further design of more detailed protein models adequate to more fully investigate the protein folding problem. Finally, the relationship between our conclusions and experimental work with specifically designed sequences is briefly discussed.

Amino Acid Sequence↗
PubMed1993

Postoperative pulmonary complications. Epidural analgesia using bupivacaine and opioids versus parenteral opioids.

BACKGROUND: Different types of analgesia have been proposed for the prevention of postoperative respiratory complications. The aim of this prospective, double-blind randomized study was to compare the impact of epidural bupivacaine and opioids versus parenteral opioids on respiratory complications in patients who had undergone major abdominal surgery. METHODS: One hundred fifty-three patients undergoing abdominal surgery for cancer were randomly allocated to receive either general anesthesia with intravenous fentanyl and postoperative analgesia with subcutaneous morphine (SC group) or general anesthesia combined with epidural bupivacaine and epidural bupivacaine plus morphine for postoperative pain relief (EP group). Analgesia was tested on a visual analog pain scale. Pulmonary complications were evaluated according to clinical complications, chest radiographs, arterial blood gas analysis, and pulmonary function tests. The evaluation was carried out on the day before the operation and on the first 5 postoperative days. Particular attention also was paid to the episodes of arterial hypotension and hemoglobin oxygen desaturation during the 1st postoperative night. RESULTS: Pain relief was significantly better in the EP group than in the SC group (P < 0.05) especially during recovery and on the 1st and 2nd postoperative days. In the EP group, vital capacity decreased less on the 1st postoperative day (P < 0.05) and arterial oxygen tension was greater in the recovery room (P < 0.05). However, no statistically significant difference was observed between the SC and EP groups in the incidence of clinical pulmonary complications (31% and 27%, respectively) and radiographic chest abnormalities (52% and 46%, respectively). The EP group recovered intestinal function earlier (P < 0.05), but significantly more patients in this group had episodes of systolic hypotension (21% vs. 8%; P < 0.05) during the 1st postoperative night. The length of the hospital stay was similar in both groups of treatment. CONCLUSIONS: Epidural analgesia with a combination of local anesthetic and opioid improves patient comfort. However, this type of analgesia does not decrease the incidence of postoperative pulmonary complications, does not reduce the length of the hospital stay, and carries the risk of complications from episodic systemic hypotension.

Abdomen↗