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Biomedical subjects

A Larena

Publications and source records attributed to A Larena.

At least 19 recordsLinked to original sources
PubMed2006

[Endovascular treatment of a thoraco-abdominal aortic aneurysm in case of a specific aortitis].

Successful endovascular repair of an aortic aneurysm of the descending thoracic aorta, laying directly cranial of the celiac artery, caused by a spondylodiscitis of the thoracoabdominal spine. While vascular surgeons refused the open resection of the infected aneurysm, endovascular treatment with a stent-graft was performed. Respecting the celiac artery by catheterisation, endovascular treatment was managed without occluding the A. Adamkiewicz. In case of an unknown infection peri- and postoperative treatment was performed of a prolonged antibiotic and corticosteroid therapy. In a follow-up of three months period, there was a complete regression of the inflammatory aneurysm and an improvement of the spondylodiscitis.

Aneurysm, Infected↗
PubMed2004

[Open therapy of carotid stenosis by endarterectomy].

Carotid endarterectomy is a routine procedure in vascular surgery. Besides clinical symptoms and the degree of stenosis, indication for surgery is influenced by the perioperative complication rate. This depends on stroke and the mortality rate and should not exceed 6% in symptomatic, high-grade stenosis, according to the Stroke Council of the American Heart Association. Techniques of carotid disobliteration include the conventional open thrombendarterectomy by means of a longitudinal arteriotomy and the eversion technique. In the former, closure by direct suture or patch plasty are possible. Different methods for cerebral protection during the clamping time exist, of which shunt protection is the most common. The various operative techniques are described and critically discussed.

Carotid Artery, Internal↗
PubMed2001

Vascular tumors simulating occlusive disease.

Two cases of vascular tumors of large vessels with intraluminal growth simulating venous thrombosis and arterial occlusive disease are reported. One was a borderline malignant epithelioid hemangioendothelioma of the femoral vein and the other a malignant epithelioid angiosarcoma of the carotid artery. Immunohistochemical studies permitted to classify the tumors. Treatment consisted in surgical resection. No recurrence and no metastasis are noted at 24 months. Uncertainty regarding biological behaviour of vascular tumors and treatment persists.

Adult↗
PubMed1996

[Blood group antigen expression in papillary carcinoma of the thyroid gland. An immunohistochemical and clinical study of expression of Lewis, ABO and related antigens].

Nine monoclonal antibodies, lectin from Ulex europaeus and neuraminidase enzyme were employed to demonstrate the occurrence of type 1 and type 2 blood group antigens in 104 cases of papillary carcinoma of the thyroid. The reagents applied, recognize the following blood group related antigens: CA-50 (sialylated type 1 precursor), CA-19-9 (sialylated Le(a)), Le(a), Le(b), A, B, H, Le(x), sialylated Le(x), and Le(y). Immunohistochemical studies revealed that papillary carcinoma of the thyroid, in contrast to histologically normal thyroid tissue, is characterised by a progressive expression of blood group antigens. Most tumours (84%) reacted with C-50 antibody, whereas only a minority of the tissues demonstrated the CA-19-9 antigen (38%). Type 2 structures Le(x) (47%) and Le(y) (13%) were found less often than their corresponding type 1 isomers Le(a) (71%) and Le(b) (62%). Desialylation with neuraminidase increased the Le(a) and Le(x) staining intensity in 27 and 44 case, respectively. Of the A, B, H antigens the A determinants encountered most frequently (24%). Comparative examinations of sequential sections of the same tumour revealed coexpression of type 1 antigens in the same areas. In carcinomas showing type 1 and type 2 antigen reactivity, a complementary distribution of the structures in different tumour areas was often demonstrated. Some tumours presented combined type 1 and type 2 antigen expression in the same cells, however, in distinct areas within the cell. A follow-up examination was carried out in 68 of the 104 cases. The observation time ranged from 12 to 217 months. Thirteen patients suffered from recurrence, of which 7 died. While lymphatic metastases occurred in 39 tumours, distant metastases were detected in 6 patients. Most of the recurrences were found in patients with tumour classification pT4 (n = 19), whereas none of the pT1 carcinomas (n = 20) showed recurrence. The clinical results were compared to the blood group antigen expression results. There was no correlation between antigen expression and differentiation degree of the tumour. The pT4 tumours showed a significant higher expression of the CA-50, CA-19-9, Le(a) and Sialyl Le(x) structures. Carcinomas expressing the Le(y) antigen were associated with a significant higher level of metastasizing capacity. The Le(y), H type 1 and H type 2 antigens occurred more frequently in recurrent tumours (n = 14). In contrast, none of the patients whose carcinomas expressed the A-antigens (n = 14) suffered from a recurrence or hematogenous metastasis. Multiple stepwise regression analysis was carried out to check the importance of each staining and clinical factor. In this analysis, "distant metastasis' was the most important parameter, whereas the staining results were of minor statistical importance.

ABO Blood-Group System↗
PubMed1995

Blood group antigen expression in malignant tumors of the thyroid: a parallel between medullary and nonmedullary carcinomas.

Blood group antigen (BGA) expression has been described in many fetal, adult, and tumorous tissues. Synthesis of BGA in the thyroid gland is regarded as oncofetal due to blood group structures that are detected in fetal and carcinomatous tissues but not in the normal adult organ. This study examined the prevalence of type 1 (CA-50, CA-19-9, Lea, Leb, A, B, H type 1) and type 2 (Le(x), Le(y), A, B, H type 2) antigens in normal thyroid (n = 25), papillary (n = 104), follicular (n = 52), anaplastic (n = 33), and medullary (n = 48) carcinomas of the thyroid. While normal thyroid tissue expressed no BGA, there was a significant increase of BGA expression in carcinomas of the thyroid gland. There are two theories about the possible origin of C cells, from which the medullary carcinomas arise. Some authors postulate that C cells belong to the amine precursor uptake and decarboxylation system and therefore derive from the neural crest, while others believe that C cells originate from the fifth pharyngeal pouch, as do the follicular cells. The results obtained in this study show that medullary and nonmedullary carcinomas correspond to one another in their BGA expression profile. Therefore it is concluded that medullary carcinomas may have the same origin as nonmedullary tumors of the thyroid.

Adenocarcinoma, Follicular↗
PubMed1994

Native and sialic acid masked Lewis(a) antigen reactivity in medullary thyroid carcinoma. Distinct tumour-associated and prognostic relevant antigens.

Forty-six medullary thyroid carcinomas (MTC) were subjected to a qualitative and quantitative characterization of native and sialic acid masked Lewis(a) (Le(a)) antigens. Immunohistochemical investigations included monoclonal antibodies (MABs) directed against alpha(2,3)-sialyl-Le(a), i.e. CA19-9 (MAB 19-9), native Le(a) (MAB anti Le(a)) and alpha(2,3)sialyl type 1 structure, i.e. CA 50 (MAB C50). To detect sialic acid masked Le(a) reactivity, MAB anti-Le(a) was also applied to native and enzymatically desialylated tissue sections with and without masking of sialic acid residues by sialic acid and sequence specific lectins. Only 7 MTC (15%) displayed a weak expression of CA19-9, while 16 (33%) showed moderate positive staining for native Le(a). Twenty-seven tumours exhibited a strong staining by the N'ase MAB anti Le(a) staining sequence. The latter could most effectively be inhibited by the simultaneous masking of alpha(2,3)-and alpha-(2,6)-linked sialic acid residues due to the competitive binding of sialic acid and sequence specific lectins: Maackia amurensis agglutinin (specific alpha(2,3)-linked sialic acid) and Sambucus nigra agglutinin (specific alpha(2,6)-linked sialic acid). Thus, in MTC the major portion of sialic acid masked Le(a) antigen reactivity is different from that detected by the MAB 19-9. The antigen reactivity is probably due to Le(a) structures containing both alpha(2,3) and alpha(2,6)-linked sialic acid residues. A highly significant correlation between the expression of CA50 and that detected by the N'ase MAB anti-Le(a) staining sequence indicates that the alpha(2,3)-sialyl type 1 chain represents a common intermediate structure within the pathway of the biosynthesis of sialylated Le(a) antigens, excluding the formation of CA19-9 via the formation of the disialyl type 1 structure. This is subsequently fucosylated to the corresponding sialic acid masked Le(a). Preliminary clinicopathological studies indicate that the sialic acid masked Le(a) antigens detected by the N'ase MAB anti-Le(a) staining sequence are related to biologically aggressive MTC.

Antibodies, Monoclonal↗
PubMed1992

Blood group antigen expression in medullary carcinoma of the thyroid. An immunohistochemical study on the occurrence of type 1 chain-derived antigens.

Using monoclonal antibodies (MoABs) against blood group determinants and related carbohydrate sequences, it is now possible to clarify their carcinoma-associated modulation at a molecular level. In the present study a panel of MoABs against different type 1 chain derived blood group antigens, comprising A, B, H type 1, Le(a), sialyl-Le(a) (CA 19-9), sialyl type 1 structure (CA 50), and Le(b) was used to investigate their immunoreactivity in 38 medullary carcinomas of the thyroid (MTC) and in normal thyroid tissue. The antigens were not expressed in normal follicular or C-cells but were expressed to a various extent in MTC. The studies revealed some characteristic anomalies in the frequency and patterns of tumor-associated antigen expression. The MoAB C 50 stained 32 of the 38 tumors, H type 1 (Le(d)) was demonstrated in 21 and the Le(b) antigen in 27. The Le(a)- and the A antigen were detected in 10 and 12 tumors and the B antigen in one. From the results some rules about the pathways for tumor-associated re-expression of these antigens can be deduced. Le(a) antigen expression was significantly correlated with the CA 50 and Le(b) antigens. The significant relation observed between A-, H1-, and Le(b) antigen formation in MTC suggests the existence of a carcinoma-associated fucosyltransferase committing the type 1 precursor chain along the H1-antigen pathway, and by further glycosylation to an A-, B-, or a Le(b) antigen. Comparative studies of tumor-associated H type 1 and H type 2 antigen expression revealed that H type 2 antigen synthesis was significantly related to a blood type 0 in the host. On the other hand, H1 antigen reactivity was independent of the AB0 blood type of the hosts and was also detected in H type 2 antigen-negative tumors. These findings support the proposal that even in tumor tissue, H antigen expression is still determined by the interaction of at least two different genes. Despite the occurrence of the precursor substance (CA 50) and the formation of the Le(a)- and Le(b) antigens, indicating the presence of a alpha 1,4-fucosyl-transferase (Lewis-enzyme), only two tumors showed the formation of CA 19-9. In conclusion, the investigations demonstrated the dominant re-expression of three type 1 chain-derived structures in MTC, namely H type 1, Le(b), and CA 50. These findings support the general concept demonstrated in other carcinomas, that fucosyl- and sialyltransferases are preferentially activated in MTC.(ABSTRACT TRUNCATED AT 400 WORDS)

ABO Blood-Group System↗
PubMed1982

[Results of surgical treatment of rupture of the Achilles tendon (author's transl)].

32 ruptures of the achilles tendon were treated surgically in the surgical department of the St. Katharinen-Hospital during the period 1. 1. 1975 to 1. 3. 1980. These cases comprised 28 subcutaneous complete ruptures and 4 open tendon injuries. 29 fresh and 3 old ruptures were operated. The article describes the surgical technique. The median, arcuate incision, the end-to-end suture according to Bunnell with Dexon and, if possible, an interlacing suture with the plantaris tendon, appear to be the essential measures. This is followed by immobilization in a plaster case for a period of 6 weeks. The patients remained hospitalized for a period of 2 weeks after the operation; they were unable to work for 10 weeks, and unable to actively participate in sports for 19 weeks. Half a year to 5 years after the operation, 25 patients were subjected to follow-up examinations. No early or late infection had occurred, and there was also no rerupture or thrombosis. There was also no adherence to tendon and skin. Using the assessment scheme according to B.G. Weber, the functional result must be classified as "good" with all patients.

Achilles Tendon↗