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Biomedical subjects

B Gasser

Publications and source records attributed to B Gasser.

At least 73 records · Page 4Linked to original sources
PubMed1993

Sensory receptor-like cells in the human foetal vomeronasal organ.

The vomeronasal organ (VNO) was studied in ten human foetuses, 12 to 36 weeks old. At 12 to 23 weeks, it was lined by a smooth pseudostratified epithelium, with neurone-specific enolase (NSE) positive cells looking like olfactory receptors. Clusters of NSE-positive cells were seen in relation with the posterosuperior end of the organ and along nerve fascicles in the nasal septum. At 36 weeks, the organ was lined by a respiratory epithelium and did not show any receptor-like cells; some pear-shaped NSE-positive cells of unknown significance were seen at the upper part of the respiratory epithelium. Our results suggest that during the early foetal period, the VNO could have some, as yet unknown, sensory function.

Female↗
PubMed1993

[Adrenal cortical tumors. Prognostic evaluation of a series of 12 cases using anti-PCNA antibodies].

Adrenocortical tumors malignancy may be difficult to assess by morphological data. Twelve cases of such tumors were reviewed and classified benign (group I) or malignant (group II) according to follow yp. Using a peroxidase antiperoxidase method, nuclear affinity for anti-PCNA antibody was studied. The percentage of positive nuclei is significantly different in both groups: the mean value is 1.025% in benign tumors (range from 0.40 to 3.02%) and 16.765% (range from 5.62 to 31.40%) in malignant tumors (p < 0.01 according to Mann and Whitney U test). Although our study group is rather small, it suggests that analysis of nuclear affinity for PCNA could be helpful in assessment of adrenocortical tumors malignancy.

Adrenal Cortex Neoplasms↗
PubMed1993

Treatment of a distal splenic artery aneurysm with splenic conservation. A case report.

We report the case of a successful treatment of a splenic artery aneurysm by aneurysm excision and direct splenic artery reconstruction allowing spleen conservation. This aneurysm was related to an arterial wall medianecrosis. Because of the reappraisal of the splenic immunological function, we believe as others that this surgical management can be a new alternative to splenectomy as treatment of splenic artery aneurysms.

Aneurysm↗
PubMed1993

[Adrenocortical tumors. I. Prognostic evaluation of a series of 17 cases using the Weiss criteria].

Weiss proposed 9 histologic criteria to evaluate the malignancy of adrenal cortical tumors. Each tumor is graded from 0 to 9 according to how many of the criteria are present. Eight of the 17 neoplasms from the present study were graded from 0 to 2; none of these 8 tumors metastasized or recurred. The grade of the nine other neoplasms ranged from 3 to 8; seven lesions metastasized (grade 4 to 8), one recurred (grade 5), and the last one neither metastasized nor recurred (grade 3) although this tumor was considered malignant according to Weiss' system. Even thought the results obtained using Weiss' system are similar to the results that were put forwards initially, and despite prognostic uncertainty with grade 3 tumors, we think that the later system provides a more objective evaluation of the prognosis of adrenal cortical tumors, compared with usual morphologic methods.

Adrenal Cortex Neoplasms↗
PubMed1993

[The malignant potential of adenofibroma and cystadenofibroma of the ovary and mesovarium. 118 cases including 13 proliferative and 5 carcinomatous].

The relationship between adenofibroma and cystadenofibroma and the frequency and features of carcinomas developed on these benign tumours are little known. Eight-hundred and forty-five epithelial tumours of the ovary diagnosed over a 10-year period have been re-examined. One-hundred and eighteen adenofibromas and cystadenofibromas were recorded. One-hundred were benign and formed an architectural spectrum from which emerged: (1) surface papillary adenofibroma accounting for 5% of the cases and appearing at a mean age of 27 years; (2) cystadenofibroma in 77.5% of the cases at a mean age of 53 years; (3) adenofibroma in 17.5% of the cases at a mean age of 64 years. Adenofibroma was bilateral in 18 cases. Among the other cases were an endometrioid cyst and two simple serous cysts. The cells were serous in 110 cases, mucinous in 6 cases and weakly acidophilic to clear in 2 cases. Eighteen of these tumours were malignant: 13 were associated with epithelial hyperplasia and 5 with a carcinoma. The 13 adenofibromas with atypical epithelial hyperplasia (at a mean age of 60 years) were all made of serous cells; 6 of them were low-grade and 7 high-grade tumours with 3 microinvasions. One patient died at the age of 78, of an unknown cause; the others are still alive after a mean follow-up of 11.3 years. The 5 invasive carcinomas appeared on an adenofibroma at the mean age of 70 years; 3 patients died (2 of metastases), one is alive after 9 years and one was loss sight of.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenofibroma↗
PubMed1992

[Rhodococcus equi infection causing pulmonary malacoplakia in a patient with acquired immune deficiency syndrome].

Rhodococcus equi is a pathogen for some animal species. It can cause opportunistic pulmonary infections in immunocompromised people. The authors describe such an infection that causes malacoplakia in a patient with acquired immunodeficiency syndrome. The likeness between lesions due to Rhodococcus equi and those due to other opportunistic germs as Mycobacterium avium-intracellulare is emphasized.

AIDS-Related Opportunistic Infections↗
PubMed1992

Malignant thymic lymphoblastic lymphoma and myasthenia gravis: an exceptional association.

Thymic lymphoblastic lymphoma and myasthenia gravis rarely coexist. Only two cases have been reported and we describe here a third case. A 60 year old man presented a typical history of myasthenia gravis, confirmed by neurological investigations including electromyography. Chest X-ray revealed an anterior mediastinal tumor. At thoracotomy, a 60 mm mass adherent to the pericardium was excised and a lymphoblastic lymphoma was diagnosed. The lymphogram showed enlarged pelvic and abdominal lymph nodes consistent with lymphoma. A m-BACOD chemotherapy regimen gave rapid and complete remission of both lymphoma and myasthenia gravis and the patient is now alive 25 months after the start of chemotherapy with no evidence of disease.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Deformation of the distal femur: a contribution towards the pathogenesis of osteochondrosis dissecans in the knee joint.

Osteochondrosis dissecans (OD) is a process of subchondral bone necrosis occurring predominantly in young individuals at specific sites. The aetiology of this disease remains controversial with mechanical processes due to trauma and/or ischaemic factors being proposed. This study aims at explaining the aetiology of OD in the knee joint as a result of the particular deformation of the condyles. A finite element analysis of the distal third of the femur was performed. A three-dimensional model was developed based on computed tomography scans of a normal femur, consisting of cortical bone, cancellous bone and articular cartilage. This model was subjected to physiological loads at 0, 30, 60 and 90 degrees of knee flexion. A complex deformation was found within each condyle as well as between the two condyles. Both medial and lateral condyles are deformed in the medio-lateral direction and at the same time compressed between the patella and the tibia in the antero-posterior direction. This effect is highest at 60 degrees of knee flexion. In both planes, the medial condyle is distorted more than the lateral one. Strain concentration in the subchondral bone facing the patella varies with flexion, especially for angles exceeding 60 degrees. The deformation of the femur in the predominant locus of OD in the medial condyle exceeds that of the lateral condyle considerably. The analysis shows that repeated vigorous exercise including extreme knee flexion may produce rapidly changing strains which in turn could ultimately be responsible for local subchondral bone collapse.

Biomechanical Phenomena↗
PubMed1991

Value of coining on the improvement of endurance in slotted intramedullary nails.

Cracking of intramedullary nails, starting at the proximal end of the partial slot and propagating in a circumferential direction, has been observed. These partial cracks are relatively frequent, although full failures are very rare and do not disturb fracture healing. Coining is a cold-working process used to improve the endurance of structures with residual compressive stresses generated by plastic deformation. The influence of coining was investigated to evaluate its practical value in controlling these fatigue cracks. Bending and torsional tests were performed on high frequency machines. Coined zones of different shapes and depths were examined, comparing the elapsed number of load cycles with crack initiation. The results showed that the endurance of coined nails was improved by factors of approximately 10 and 5 in bending and torsion, respectively. This increase in fatigue life corresponds to a more than 50% larger dynamic load after a million cycles. Variations in coining shape and depth did not yield any significant differences.

Bone Nails↗
PubMed1991

[Non-aplastic N2 operated bronchial cancers. Multifactorial analysis of the prognosis].

The marked disparity of the published 5-year survival rates (0 to 3%) for non-anaplastic, operated N2 lung cancers would suggest the marked heterogeneity of the patients studied. We prospectively studies 97 N2 tumours for which "curative" resection was performed between 1983 and 1986. The overall survival rate was 28% at 3 years, 19% at 4 years and 12% at 5 years. Survival was studied on the basis of several parameters concerning the tumour: histological type and degree of differentiation, T (TNM), modality of invasion (circumscribed, infiltrating), the quality of the stroma (absent, fibrotic, cellular), the mitotic index, the necrosis rate, presence or absence of microscopic invasion of blood vessels; and concerning the nodes: site, number (solitary, multiple), size of the metastasis (massive, microscopic), macroscopic or microscopic invasion of the capsule. We know the outcome for all of our patients: 81 have died and 16 are still alive. Sixty-one have developed metastases, 5 have developed local and regional recurrences and 3 have both a recurrence and metastases. Univariate analysis demonstrated that a small number of parameters significantly influence survival: microscopic invasion of blood vessel (chi 2 = 5.24, p less than 0.02), macroscopic and microscopic invasion of the lymph node capsule. In order to more clearly define the prognostic factors, we used Cox's multidimensional model. This model was applied to the three significant parameters to which we added two other variables which non-significantly tended to be related to survival: tumour necrosis and number of lymph nodes involved.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1991

[Arthrogryposis and maternal myasthenia gravis. Risk of recurrence].

A 26-year old myasthenic woman whose disease had been in remission for more than 4 years gave birth, at the end of 2 induced pregnancies, to 2 stillborn infants with arthrogryposis. The presence of inherited antibodies directed against acetylcholine receptors most probably does not explain the diffuse retractions. This case illustrates the risk of recurrent foetal arthrogryposis after a first abnormal pregnancy in women with myasthenia gravis.

Adult↗
PubMed1991

[Carcinoma cuniculatum. Apropos of 4 cases with orofacial involvement].

Carcinoma cuniculatum, a rare variant of verrucous carcinoma, was first described in the foot. The authors report 4 cases of uncommon localizations of this tumor, involving oral cavity and face, 3 of them having a 6-year follow-up. The specific histological and clinical features of this tumor are remembered and the difficulties of its diagnosis are emphasized. This slow-growing, ulcerated proliferation, invading the surrounding tissues, is often responsible for chronic suppuration, but very rarely metastasizes to the regional lymph nodes. The surgical treatment consists in a wide excision; neck dissection is theoretically useless, and radiotherapy is strictly contraindicated because of the risk of transformation into an anaplasic carcinoma. For all these reasons, carcinoma cuniculatum must be considered as an anatomoclinic entity, and deserves to be known by the clinicians and the pathologists.

Carcinoma, Papillary↗
PubMed1990

Stiffness characteristics of the circular Ilizarov device as opposed to conventional external fixators.

Ilizarov proposes the use of a special circular fixation device for treatment of bone defects and nonunions or for limb lengthening. Supposition was that the success of this method has to do with the specific mechanical behavior of the device. This behavior is a result of the configuration of the fixation elements. Therefore, a mechanical study of the sensitivity of the circular compression and distraction device (CDD) to configuration parameters was performed. The CDD was found to exhibit a nonlinear stiffness behavior, in particular under axial load. This may be favorable for the induction and tolerance of bone formation. Among the different parameters tested the ring radius was the most important with respect to stiffness. In general, the stiffness of the CDD allows adjustment during postoperative management. In magnitude, it is equal or lower when compared to other fixator types.

Equipment Design↗
PubMed1990

[Endobronchial aspergillosis associated with a carcinoid tumor].

We report a case of a 62 year old man who presented with effort dyspnoea accompanied by a cough and haemoptysis. The chest radiograph of the thorax showed atelectasis of the right upper lobe. Bronchoscopy showed evidence of a tumour like mass obstructing the right bronchus and this revealed itself to be a mass of organised fibrinous deposit in granulation tissue containing numerous colonies of Aspergillus. In fact it appeared to be an obstructive Aspergillus bronchitis, with a pseudo-tumour appearance attached to a carcinoid tumour which was obstructing the apical segment of the right upper lobe. Obstructive Aspergillus bronchitis makes up only a small percentage of overall respiratory disease caused by Aspergillus. They pose a problem of differential diagnosis with bronchopulmonary aspergillosis which is much more frequent.

Aspergillosis↗
PubMed1990

[Development of 62 typical carcinoid tumor of the bronchi surgically treated. Prognostic value of histopathological features].

The pathological and clinical features of 62 carcinoid tumours of the bronchus operated between 1975 and 1987 were reviewed in order to determine the prognostic value of certain parameters: limit of proliferation, vascular invasion, lymph node involvement. This series corresponded to 36 central tumours and 25 peripheral tumours, all treated surgically. One patient was lost to follow-up, 3 developed recurrences, 56 are still alive without recurrence and 3 died from intercurrent causes. The histological appearance of the tumours was homogeneous and typical. Twenty-eight lesions were strictly intrabronchial, 34 invaded the lung with incomplete limits in twenty cases. The tumour showed signs of vascular invasion in ten cases and the adjacent lymph nodes were invaded in eight cases. The local recurrence was undoubtedly related to an excessively conservative primary resection, as the primary tumour did not demonstrate any unusual features. The two tumours which metastasized showed vascular invasion: one metastasized to a hilar node, but these features were observed in other cases which retained a benign course. The standard histological diagnosis of typical carcinoid tumour does not appear to raise any particular difficulties; it is reliable. The course of the disease is sometimes malignant but no histological parameter is able to accurately predict this outcome.

Adult↗
PubMed1989

The effect of radial preload on the implant-bone interface: a cadaveric study.

The most common complication of external fixation is pin loosening. Preloading the implant-bone interface is believed to retard this process. Radial preload, in particular, may be useful, as it allows loading in more than one direction. To investigate the effect of varying degrees of radial preload on the pin-bone interface, 30 freshly thawed human cadaveric tibiae were sectioned into 4-cm segments. Uniform drill holes were produced in the anterior tibial ridge of all segments and custom experimental bolts, oversized in diameter by as much as 1 mm, were pressed into each specimen. Macroscopic surface fractures were noted at the time of bolt insertion for misfits greater than 0.2 mm. Following histologic preparation, the implant-bone interface was evaluated microscopically based on the appearance of osteonal compression, lamellar distortion, and microfractures. Insertion of external fixator pins with misfits of greater than 0.4 mm resulted in significant microscopic structural damage to the bone surrounding the pin. High degrees of radial preload, exceeding the elastic limit of cortical bone, may be produced around pin holes by a small misfit. The use of oversized pins or screws must therefore be questioned.

Biomechanical Phenomena↗