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Biomedical subjects

L Linnet

Publications and source records attributed to L Linnet.

At least 19 recordsLinked to original sources
PubMed1993

Testicular torsion: a follow-up study.

Thirty-five patients were examined 6-11 years after operation for torsion of the testis. Loss of testicular tissue was significantly associated with long preoperative duration of symptoms and with low postoperative sperm counts. The sex hormones were normal in the majority of patients but there were significantly higher levels of both FSH and LH in the group of patients with symptoms exceeding 8 hours. There was also a higher prevalence of abnormal semen quality in the same group. Furthermore, FSH and LH levels correlated significantly to the duration of symptoms and correlated inversely to the sperm count and concentration. Measurement of carnitine levels in seminal plasma, as a sign of vas deferens obstruction or dysfunction of epididymis, and of autoantibodies against spermatozoa revealed no significant findings.

Adolescent↗
PubMed1991

Antisperm antibodies on epididymal spermatozoa.

Still under debate is the location in the genital tract where antisperm antibodies transuded from serum and locally produced antibodies, respectively, become attached to the surface of the spermatozoa. The mixed antiglobulin reaction (MAR) for immunoglobulin (Ig) G, IgA, and locally produced secretory IgA (sIgA) could be carried out on motile spermatozoa from epididymis from 13 of 34 men undergoing vasovasostomy. Four months and one year after the operation the MAR was repeated on a fresh semen sample from all patients. It was found that transuded as well as locally produced antisperm antibodies were bound to spermatozoa at the epididymal level of the genital tract. The follow-up results on semen were almost identical to the results obtained with epididymal spermatozoa.

Adult↗
PubMed1990

Antisperm antibodies and fertility after vasovasostomy: a follow-up study of 216 men.

A group of 216 vasovasostomized men were tested with the mixed antiglobulin reaction for immunoglobulin (Ig)G, IgA, and secretory IgA antisperm antibodies bound to the sperm membrane. Free antisperm antibodies in serum and seminal plasma were detected with the gelatin agglutination test and the tray agglutination test. The results were related to the conception rates. In a subgroup with a pure IgG response, the conception rate reached 85.7%, whereas only 42.9% of the men who also had IgA on the sperm induced pregnancy. When 100% of the spermatozoa were covered with IgA, the conception rate was reduced to 21.7%. The combination of IgA on all sperm and a strong immune response (titer in serum greater than or equal to 256) was associated with a conception rate of zero.

Antibodies↗
PubMed1989

Human lung cancer--a comparative study of the levels of circulating immune complexes in pulmonary blood draining the tumor area and peripheral venous blood.

Our objective was to investigate whether low levels of circulating immune complexes (cICs) in peripheral venous blood of cancer patients could be due to removal of cIC released at the tumor site during passage to the peripheral veins. In 54 patients with primary lung cancer, we therefore compared the cIC levels as detected by 3 different assays in paired samples from the pulmonary vein draining the tumor area and from a peripheral vein. Only 6 of the 54 patients had significantly increased pulmonary vein cIC levels as compared to the corresponding peripheral vein levels. The peripheral vein levels of these 6 patients were all within the normal range, and in none of these patients was the difference between the 2 sites of analysis--although significant--of such a magnitude that the pulmonary vein cIC level appeared higher than the normal range, i.e., "positive" for cIC. Positive cIC levels were only found in 11% of lung cancer patients (irrespective of the site of measurement). Thus, our present data, together with our previous findings indicating no significant difference between peripheral venous blood cIC levels in cancer patients and normal controls, contradict the theory of tumor cells expressing new antigens resulting in the formation of tumor-associated cICs.

Antigen-Antibody Complex↗
PubMed1989

Analysis of the decreased NK (natural killer) activity in lung cancer patients, using whole blood versus separated mononuclear cells.

The aim of this study was to analyze whether a whole blood assay would give a more correct measure of NK activity than assays using separated mononuclear cells (SMNC). We found that the NK activity of whole blood was higher than the NK activity of SMNC in the 28 lung cancer patients investigated (p = 0.01), whereas this difference between the assays could not be demonstrated in the 29 healthy controls. Since no differences were found between the NK activity of washed blood, SMNC, and monocyte-depleted lymphoid cells, there was no indication that the lower NK activity of SMNC in comparison with whole blood was due to cell loss or to a systematic disturbing effect due to monocytes. The possible effect of plasma factors on the whole blood NK activity was analyzed by comparing whole blood and washed blood. The NK activity of whole blood was increased in comparison with washed blood in the lung cancer patients (p less than 0.0001) indicating a stimulatory effect of plasma. Further, the finding that the reactive capability of lymphocytes from cancer patients was higher than in controls could indicate preactivation of the lymphocytes from the cancer patients due to the presence of stimulatory plasma factors. The NK activity of lung cancer patients was lower than the NK activity of healthy controls. The difference was found to be smaller with whole blood than with SMNC as effector cells, although both differences were significant. The decreased NK activity of cancer patients could be due to blocking immune complexes (IC), but we found no evidence for circulating or cell-bound IC in the lung cancer patients.

Adult↗
PubMed1983

Comparison of different assays for circulating immune complexes in age matched vasectomized and non-vasectomized men.

Sera from 46 men vasectomized for 5 yr and from 46 age-matched nonvasectomized men had previously been analyzed for circulating immune complexes (CICs) by four assays. Four additional CIC assays have now been performed on these sera: three Raji cell enzyme-linked immunosorbent assays (ELISAs) using alkaline phosphatase-conjugated antihuman IgG, IgA or C3 and the bull sperm ELISA. No significant differences in CIC levels were detected between the two groups using any of the assays. Results for two different sera obtained from 16 men 4 1/2 months apart correlated significantly for six of seven CIC assays evaluated in this way. In the bull sperm and Raji cell ELISAs, utilizing anti-IgG in the detection layer, the vasectomized men with sperm-agglutinating antibodies were found to have significantly higher CIC levels than those without sperm agglutinants. No association was found between the presence of sperm protamine antibody and levels of CICs. Since the vasectomized and control groups did not differ with respect to levels of CICs, immunoglobulins, or the complement C3 split product C3d, all 92 samples were combined into one group for further analysis. Serum IgG levels significantly correlated with the CIC levels in four of five CIC assays involving binding of IgG; IgA levels correlated with CIC determinations in the Raji-IgA assay, while plasma C3d levels correlated with the Raji-C3, the Raji-IgA, and the C1q-protein A binding assays. IgM levels did not correlate with activity in any assay. Finally, the degree of correlation between all eight CIC assays was determined, and significant positive correlations between assays were found in ten of twenty-eight comparisons.

Adult↗
PubMed1982

A comparison of eight techniques for the evaluation of the auto-immune response to spermatozoa after vasectomy.

The tray agglutination tests (TAT), gelatin agglutination test (GAT), side agglutination test (SAT), tube-slide agglutination test (TSAT), sperm immobilization test (SIT), ATP-release cytotoxicity test (ARCT), indirect immunofluorescence technique (IFT) on methanol-fixed, intact spermatozoa, and a lymphocyte transformation test (LTT) were compared using a maximum of 329 blood samples taken from 47 men before and after vasectomy. The TAT, GAT, TSAT, SIT and ARCT discriminated between the pre- and post-vasectomy samples, and the sensitivity for sperm antibodies decreased in that order. The activity in the IFT and the LTT did not change significantly after vasectomy. In the TAT the mode of agglutination varied with serum dilution; the results for the 1:4 dilution showed the best agreement with the SAT results. Almost all TAT activity was detected by a combination of GAT and TSAT. Sperm agglutinins were present in all serum samples positive in the two complement-dependent tests, SIT and ARCT. If improved in sensitivity, the ARCT, which lacks the subjective elements of microscopy, might be suitable for the screening of male sera in clinical work. For the present, we recommend the TAT.

Autoantibodies↗
PubMed1982

Immunoglobulin classes, secretory component, and sperm agglutinins in semen after vasovasostomy.

The immunoglobulin classes of the sperm-agglutinating antibodies in the seminal fluid and serum from four vasovasostomized men, as well as in operatively obtained testis-epididymis fluid from two of them, were investigated by specific solid-phase absorption of IgG, IgM, and IgA. In two patients the major part of the seminal agglutinins was IgA, and in one IgG, indicating that both local production and diffusion of sperm agglutinins from serum to the testis-epididymis compartment may take place. The total levels of immunoglobulins in seminal fluid generally increased after the operation, and IgM was present in two postvasovasostomy samples. This suggests a pathotopic potentiation effect of the vasectomy on the epithelial lining of the testis-epididymis compartment. Comparison of the results of solid-phase absorption with anti-IgA and anti-secretory component (SC) pointed to the presence of "free" SC in postvasovasostomy seminal fluid.

Agglutinins↗
PubMed1982

No increase in arteriolosclerotic retinopathy or activity in tests for circulating immune complexes 5 years after vasectomy.

On the basis of studies in monkeys, the hypothesis has been proposed that vasectomy induces the formation of circulating immune complexes (CICs), which--via activation of the complement system--may result in immune injury of the endothelium and thereby exacerbate atherosclerosis; the same mechanism has been suggested to cause retinal arteriolar changes in vasectomized men. We compared 46 men, 5 years after vasectomy, with 46 age-matched control subjects and found no difference in the distribution of arteriolosclerotic retinopathy gradings evaluated by ophthalmoscopy and fundus photography. Blood samples from the two groups were collected and handled identically, and no significant difference in activity was found in four different tests for CICs and two tests for split products of complement factor C3. Thus, the results do not support the hypothesis that changes mediated by CICs occur in vessels after human vasectomy.

Adult↗
PubMed1981

Association between failure to impregnate after vasovasostomy and sperm agglutinins in semen.

Sperm agglutinins emerging from the reopened part of the vas deferens were found in the seminal fluid of 10 out of 29 men after vasovasostomy. There was a strong association between the presence of these antibodies and the failure to impregnate over a period of 14 to 33 months. Of 20 couples, 11 pregnancies resulted among the 13 women whose men had no sperm agglutinins in the seminal fluid, but only 1 among the 7 whose men had such antibodies, 2p = 0.0044. The presence of sperm agglutinins in the seminal fluid was always associated with their presence in the serum, usually in a higher titre. Preoperative serum levels thus are highly predictive of ability to impregnate after reversal of vasectomy.

Adult↗
PubMed1981

Submicroscopic localization of human sperm antibodies.

In this paper the localization of three antisperm sera obtained from vasectomized men has been studied at submicroscopic level. The sera have been demonstrated to react respectively with the acrosin, the columns and the dense postacrosomal sheath, that appear to be made up of specific proteins, absent from other sperm regions. No serum has been found active against the more widely distributed proteins tubulin, dynein or actin.

Acrosome↗