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Biomedical subjects

A Horn

Publications and source records attributed to A Horn.

At least 91 records · Page 5Linked to original sources
PubMed1989

[Quantitative acetylcholinesterase (AChE)--determination in amniotic fluid--potential for differential diagnosis in consistently high AFP levels during general AFP screening for prenatal diagnosis of open neural tube defects].

Measurement of maternal serum alpha-fetoprotein concentration for prenatal detection of open neural tube defects had been introduced into the obstetrical care of pregnant women in the district of Schwerin since 1983. In cases of high risk for presence of an open neural tube defect, noticed by elevated levels of maternal serum alpha-fetoprotein concentration step by step further diagnostic steps are necessary. In addition to special examination by ultrasound and measurement of alpha-fetoprotein concentration in amniotic fluid quantitative analysis of acetylcholinesterase activity in amniotic fluid seems to be valuable. Reliability of detecting open neural tube defects in prenatal care had been proved by quantitative analysis of acetylcholinesterase activity in amniotic fluid. The existing results up to now were very reliable, especially biological transit stages from normal to pathological findings were taken into consideration, too. In these cases further controls are necessary. Levels of acethylcholinesterase activity below the 90th percentile can be considered as normal findings, levels above the 99th percentile must be interpreted as pathological findings. These are our experiences up to date.

Acetylcholinesterase↗
PubMed1989

Isolation of Eikenella corrodens from a liver abscess. Case report.

Eikenella corrodens was isolated from a posttraumatic liver abscess in a man with previous hemicolectomy for sigmoid adenocarcinoma. Escherichia coli was the initial isolate, but sepsis persisted after its eradication by cefuroxime and metronidazole. A second specimen yielded E. corrodens which responded promptly to combined ampicillin and netilmicin. The patient died of disseminated cancer 6 months later.

Athletic Injuries↗
PubMed1988

Low molecular weight heparin given the evening before surgery compared with conventional low-dose heparin in prevention of thrombosis.

A prospective randomized double-blind trial was performed comparing conventional low-dose heparin with a low molecular weight heparin fragment for thromboprophylaxis in elective general abdominal surgical patients. The first dose of the heparin fragment was given the evening before surgery, and further doses were given thereafter every evening. There were 1002 analysable patients, 826 having received correct prophylaxis. Of these 1002 patients, 64 per cent were operated on for malignant disease. A total of 20 patients died, 10 in each group. The frequency of deep vein thrombosis was significantly reduced among patients with correct prophylaxis with the heparin fragment (9.2-5.0 per cent, P = 0.02) [corrected]. The frequency of bleeding was 6.7 per cent among the heparin fragment patients and 2.7 per cent among the patients given conventional heparin (P = 0.01), but all bleeds were of minor degree and there was no difference in the reoperation rate for bleeding, or in the transfusion requirements. Local pain at the injection site was reported significantly less often among patients given the heparin fragment.

Abdomen↗
PubMed1988

[Prenatal detection of open neural tube defects in a mass screening program by determination of alpha-fetoprotein concentration in maternal serum].

A partially automatized ultramicroencymimmunoassay developed by the GDR and Cuba should be tested in a mass screening for the prenatal detection of open neural tube defects by measurement of maternal alphafetoprotein concentration (MS-AFP). In the screening program 24,271 pregnant women were included (Berlin/District of Schwerin). In 18,144 patients AFP-concentration in maternal serum was measured as a routine procedure in the care for all pregnant women of the district of Schwerin. The time of MS-AFP determination in this connection was limited from 15th to 18th completed gestational week. 1986 already in 84.9 per cent of all pregnant women of the district of Schwerin MS-AFP concentration could be measured in early pregnancy. The detective rate of open neural tube defects among 24,271 tested pregnant women was 86.1 per cent. AFP concentration was expressed in ng/ml and the "cut off" was set at 2.0 MOM. Infants born with open neural tube defects were reduced by 75 per cent under the conditions of MS-AFP screening. Better results are possible in connection with a progress in the qualification of the following diagnostic steps, if MS-AFP-levels are elevated. Not unexpected and unspecific MS-AFP-elevation was found in connection with twin pregnancies and a higher risk of abortion and the delivery of infants with very low birth-weight less than 1,500 g. A general MS-AFP-screening is recommended for prenatal detection of open neural tube defects all over the country.

Anencephaly↗
PubMed1988

[Thrombolytic therapy of deep venous thrombosis with rt-PA].

Recombinant human tissue-type plasminogen activator (rt-PA) was given to seven patients with phlebographically documented deep vein thrombosis at a dose of 60-120 mg/day (0.71-1.76 mg/kg body weight/24 h) for 2 to 4 days. rt-PA induced evident recanalization in 6 of 7 cases. The lowest here used dose of 0.71 mg/kg/24 h was thrombolytical highly effective, but a dose of 1.4 mg/kg/24 h and over was accompanied by bleeding from venous puncture sites. Coagulation analysis showed no obvious decrease of fibrinogen, while euglobulin clot lysis time and thrombelastography demonstrated the systemic fibrinolytic activity. Thus, therapy with rt-PA may represent an alternative and effective therapeutic procedure in treatment of venous thrombosis. The initial results make a case for expanded investigational use of rt-PA in patients with deep vein thrombosis to clarify conceivable advantages of therapy with this fibrin selective thrombolytic agent.

Blood Coagulation Tests↗
PubMed1987

Large scale purification of intralumenal alkaline phosphatase from calf intestine by immunosorbent affinity chromatography.

Electrophoretically and immunologically homogeneous alkaline phosphatase (AP) can be obtained by a simple and rapid two-step procedure. Step 1: Immunosorbent affinity chromatography using immobilized polyclonal anti-AP-antibodies and elution of the bound enzyme by triethylamine solution, pH 11.4. After affinity chromatography the specific activity of the extracted crude material increases from 3.5 to 793 IU/mg. Step 2: Final purification to a specific activity of 1524 IU/mg by DEAE-cellulose ion exchange chromatography. One investigator is able to purify 100 mg AP within 3 days. The overall recovery is 65%. Methods for characterization and selection of anti-AP-antiserum using immunoinhibition of AP are described.

Alkaline Phosphatase↗
PubMed1986

Maternal serum alpha-fetoprotein screening for neural tube defects and other disorders using an ultramicro-ELISA. Collaborative study in Cuba and in the German Democratic Republic.

In Cuba and in the German Democratic Republic (GDR) a total of 24,412 pregnant women were tested for maternal serum alpha-fetoprotein (MSAFP) at the 16th to 20th week of gestation. An inexpensive and partly automated ultramicroliter enzyme immunoassay (ELISA) with final volumes of 10 microliter was used to analyze simultaneously 50 samples. The intraassay coefficient of variation (CV) of 5-8% and day/day CVs of 6-10.5% were obtained with a test frequency of 320 assays/day. A cut-off level of twice the median value (MoM) was chosen. An amniocentesis was done in a total of 0.5% (in the GDR) and 0.7% (in Cuba) of the screened women. The prevalence of open neural tube defects (ONTD) was calculated from the present study and was 1.43% in Cuba and 1.34% in the GDR. Through MSAFP screening 88.2% ONTD were detected. There was no therapeutic abortion of a normal fetus. The approximate cost for this program was about 2.36 marks-GDR per patient screened, or about 2,048 marks per ONTD detected.

Abortion, Spontaneous↗
PubMed1986

Lipid-A-antibodies--indicators for the risk of renal scarring in children with urinary tract infection.

The levels of IgG- and IgM-antibodies against lipid A were determined by an ultramicro-ELISA in 54 children between 2 months and 13 years of age with non-obstructive urinary tract infections at the onset of the infection and subsequently after 3, 6 and 12 months. Children older than 2 years who later developed renal scarring as shown by intravenous pyelograms had higher levels of IgG antibodies than those without scars. This correlation was not found in children younger than 2 years of age. IgM-antibody levels did not correlate with the risk of scar formation. We conclude that the IgG-antibody level against lipid A is a useful indicator for early recognition of children over the age of two years who will later develop renal scars. The ultramicro-ELISA technique makes screening for children at risk possible at a low cost.

Adolescent↗
PubMed1986

Two-stage median-based methods for characterizing enzyme inhibition.

Non-parametric linear regression is used for inhibition diagnostics and parameter estimation based on the velocity equation v = sKsV/(1 + sKS + iKI + isKIS) = sV(i)/(K(i) + s) = W(s)/(L(s) + i). From velocities measured as a function of inhibitor level i at different constant substrate levels s, median-based estimates of 1/W(s) and L(s)/W(s) are derived. Different diagnostic secondary plots are introduced, which take special shapes at limiting inhibition types. Two-stage median-based methods are presented for fitting the four-parameter equation to the observed velocities. These methods cause only little computational effort in contrast to one-stage median-based estimation which requires medians to be taken of solutions of impracticably large numbers of linear equation systems. Performance of the new methods is compared with that of the least-squares fit by application to simulated velocity data. For velocity data containing outliers, the median-based estimates are superior to the least-squares ones, whereas for normally distributed data the reverse is true.

Enzyme Inhibitors↗
PubMed1985

Alkaline phosphatase of the calf intestine hydrolyzes phospholipids.

Pure alkaline phosphatase of the calf intestine is able to hydrolyze phosphatidylinositol 4,5-diphosphate (TPI) to phosphatidylinositol and Pi and to dephosphorylate phosphatidic acid. This phosphomonoesterase activity shows a considerably high specific activity when an incubation medium at neutral pH containing 3 mM deoxycholate is used. The activity is inhibited by low concentrations of Ca2+. The enzyme has no detectable phosphodiesterase activity under the conditions tested.

Alkaline Phosphatase↗
PubMed1985

[Alpha 1-fetoprotein--a marker of potential PUVA side-effects in psoriasis?].

Serum concentrations of alpha 1-fetoprotein (AFP) during PUVA treatment have been analyzed in 12 patients suffering from severe psoriasis or psoriatic arthritis. The results have been compared with AFP levels in psoriatics without PUVA treatment (group II), patients with psoriatic arthritis treated with methotrexate (group III), as well as dermatological patients without psoriasis (group IV). All groups revealed AFP levels below 25 ng/ml. Although a slight raise of AFP could be observed during PUVA therapy (p less than 0.005), we assume that AFP detection cannot be regarded as a marker of potential PUVA side-effects in psoriasis.

Adolescent↗