Characterization of SM201, an anti-hFcγRIIB antibody not interfering with ligand binding that mediates immune complex dependent inhibition of B cells.

The monoclonal antibody SM201 specifically recognizes the human inhibitory FcγRIIB without showing cross-reactivity to the related but activating FcγRIIA. The epitope recognized by SM201 is located outside the IgG-binding site of FcγRIIB. As a result, the antibody does not interfere with hIgG binding to the receptor. It was therefore hypothesized that SM201 may amplify the inhibitory signaling of FcγRIIB after coligation of B cell receptor (BCR) and FcγRIIB by immune complexes (ICs). Mechanistic and functional studies were conducted in established B cell lines as well as in primary B cells from healthy donors to substantiate the anticipated working principle. Using an experimental setup mimicking IC binding, we were able to demonstrate that SM201 enhances the extent of ITIM phosphorylation of FcγRIIB. The antibody works synergistically with ICs and the mode of action is strictly dependent on their presence. Additionally, SM201 did not induce apoptosis, cellular depletion or NK cell activation, which indicates an advantageous safety profile. This establishes an innovative approach for the treatment of antibody-mediated autoimmune diseases.

Detection of a novel human coronavirus by real-time reverse-transcription polymerase chain reaction.

We present two real-time reverse-transcription polymerase chain reaction assays for a novel human coronavirus (CoV), targeting regions upstream of the E gene (upE) or within open reading frame (ORF)1b, respectively. Sensitivity for upE is 3.4 copies per reaction (95% confidence interval (CI): 2.5­6.9 copies) or 291 copies/mL of sample. No cross-reactivity was observed with coronaviruses OC43, NL63, 229E, SARS-CoV, nor with 92 clinical specimens containing common human respiratory viruses. We recommend using upE for screening and ORF1b for confirmation.

Anti-cancer actions of a recombinant antibody (R6313/G2) against the angiotensin II AT1 receptor.

Although several tumour types express both AT1 and AT2 angiotensin II receptors, and angiotensin II stimulates cell proliferation, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers are not effective anti-cancer agents. Development of a biologically active monoclonal antibody (6313/G2) against the AT1 receptor prompted the testing of a recombinant short-chain variable fragment form (R6313/G2) against breast cancer cells in vitro and in vivo. Cell lines MCF-7, MDA-MB-231 and T47D all expressed both receptor subtypes. In vitro, R6313/G2 suppressed cell proliferation in the presence of 100 nM angiotensin II, with IC50s of 30 nM, 153 nM and 2.8 microM for the three cell types respectively; in contrast, the AT1 receptor blocker losartan was effective only in T47D cells, at 25 microM. Studies on MCF-7 and T47D cells showed R6313/G2 also opposed the angiotensin II-induced inhibition of caspase-3/7 activity. In vivo, hollow fibres containing the cell lines were implanted in nu/nu balb-c mice at two sites, s.c. and i.p. Treatments of R6313/G2 at 2.5 nmol/kg and 25 nmol/kg twice per day for 7 days dose dependently reduced cell numbers for all three cell lines, but here MCF-7 cells responded most sensitively and MDA-MB-231 cells least. Although T47D cells were refractory at the s.c. site, growth was inhibited at the i.p. location, and otherwise results were similar at the two sites. In xenografts, MCF-7 cell tumours were dose dependently reduced by R6313/G2, and 13 and 27 nmol/kg R6313/G2 twice/day gave means of 74 and 76% tumour regression after 7 days. The data suggest that the anti-cancer action of R6313/G2 is considerably more effective than AT1 antagonists.

Nuchal translucency measurement and congenital heart defects: modest association in low-risk pregnancies.

OBJECTIVE: To assess the performance of nuchal translucency (NT) measurement in the first trimester of pregnancy as a marker for congenital heart defects (CHD) in the fetus in a low-risk obstetric population. METHODS: Nuchal translucency screening was offered over a 3-year period to consecutive pregnant women without known a priori risk factors and attending midwife practices in three different areas in the Netherlands. In chromosomally normal fetuses and infants from the study population the NT measurements were matched with CHD detected either prenatally or postnatally. RESULTS: NT screening was offered to 6132 women with an uptake of 83%. A total of 4876 NT measurements was performed. Pregnancy outcome data were available in 4181 cases (86%). Defects of the heart and great arteries (CHD) were diagnosed in 24 cases (prevalence 5.8/1000). Thirteen of these were classified as major (prevalence 3.1/1000). Two major CHD occurred in fetuses showing an increased NT at the first-trimester scan. The sensitivity of NT measurement > 95th and > 99th percentile for all CHD and for major CHD, was 8% and 15%, respectively. The positive likelihood ratios of NT > 95(th) and > 99th percentile for major CHD were 6, 5 and 33, respectively. CONCLUSION: In pregnancies without known risk factors also, an increased NT is associated with major cardiac defects in the fetus and therefore represents an indication for specialized fetal echocardiography. However, this association is too weak to envisage a role for NT measurement as single screening strategy for the prenatal detection of cardiac defects.

State of the art 3D imaging of abdominal organs.

Since its introduction in the late 70's 3D imaging has assumed growing importance for the visualization of abdominal pathologies. Main clinical applications include the preoperative planning for resection of liver, pancreas and kidney tumors, living-donor liver and renal transplantation, and tumor radiofrequency ablation of liver and kidney. The advantages of 3D imaging are the exact visualization of vessels in areas with complex and variable vascular anatomy, demonstration of possible resection margins, and predicting operative risks, especially when dealing with complex or minimal invasive surgery. 3D imaging is an important visual aid for the surgeon in order to facilitate crucial decisions and to lower the operative risk. In future, 3D planning and simulation of operations will be become standard procedures. Therefore an efficient use of 3D imaging is not possible without a close collaboration between radiologist and surgeons.

[Ultrasound screening for Down's syndrome early in pregnancy: nuchal translucency thickness]. / Echoscopische screening op het syndroom van Down vroeg in de zwangerschap: de nekplooimeting.

Screening for Down's syndrome (DS) in the Netherlands is based on maternal age. Women aged 36 years or above are offered amniocentesis or chorionic villus sampling to determine if the foetus has Down's syndrome or other chromosomal abnormalities. Disadvantages of this method are a low detection rate of affected pregnancies (no more than 15%) and iatrogenic miscarriages (0.5-1%). Pregnant women under the age of 36 are not eligible for screening, even though 70% of the children with Down's syndrome are born in this age group. Screening by measuring nuchal translucency thickness, an early ultrasound marker for Down's syndrome carried out in the first trimester of pregnancy, has a higher detection rate with a less invasive method and therefore fewer iatrogenic miscarriages. However, Dutch law prohibits the offer of screening to women with a low individual risk of DS (Population Screening Act), because of the anxiety this may provoke in these women. The Dutch Health Council's Prenatal Screening Committee has advised the minister of Public Health, Welfare and Sport that risk-assessment screening, in particular the triple test, should no longer be postponed and that research into (other) screening options should be stimulated.

[Outcome after hospital rehabilitation of patients with myocardial infarct]. / Verlauf nach der stationären Rehabilitation von Herzinfarktpatienten.

A series of follow-ups were carried out in 947 patients who had 12 to 28 months previously (average 16.6 months) undergone a period of rehabilitation at this clinic in Gais . 17 patients were not traced, but from the remaining 930 patients, 35 (3.8%) had died of cardiac disorders, 21 had had nonfatal infarctions, and 51 patients had undergone aortocoronary bypass operation by the follow-up period. The prevalence and grade of angina pectoris (NYHA functional classification) in 816 patients from whom data was obtained remained unchanged. Even after exclusion of all patients with reinfarction or bypass surgery, there was no increase in the severity of angina pectoris in the remaining 752 patients. 705 patients had returned to work, 555 of whom were still in full employment and 118 part-time , while 32 remained active housewives. From the remaining 112 patients who were not working, 55 had retired. In conclusion, a stable course and high grade of employment were observed during the first year after infarction in patients who had undergone a course of rehabilitation at this clinic.

Danazol in the treatment of endometriosis externa.

Thirty-six women with endometriosis externa were treated with danazol (Ladogar; Winthrop Laboratories, Division of Sterling Drug (SA) (Pty) Ltd) for 6 months. In 15 cases treatment was combined with conservative surgery. Of these patients 34 presented with the complaint of infertility. The results were evaluated by means of repeat laparoscopy and biopsy. Of 21 patients treated with danazol only 9 (42,9%) were completely healed, and 10 (47,6%) showed a good response, giving an overall response of 90,5% and a corrected conception rate of 52,9%. Of the 15 patients who were treated with danazol combined with conservative surgery, 9 (60%) have completely healed, and 3 had a recurrence of endometriosis. This group had a corrected pregnancy rate of 30,8%. The majority of conceptions (61,5%) occurred during the first 6 months after treatment, 92,3% within the 1st year and 1 a year after conclusion of treatment. Of the 13 conceptions, 11 were successful, 1 ended in an abortion and 1 in an ectopic pregnancy, and 1 small-for-gestational-age infant was delivered.

Serum-alpha-hydroxybutyrate dehydrogenase levels in sickle-cell disease and sickle-cell crisis.

In patients with sickle-cell disease (Hb S/S disease) who are not in crisis, the serum-level of alpha-hydroxybutyrate dehydrogenase (alpha-H.B.D.) is significantly above normal. The degree of elevation correlates with the severity of the disease. During infarctive crises the level increases still further by a factor of 2 to 3, and it returns to the patient's normal level on recovery. The level of alpha-H.B.D. thus provides an index of the severity of the disease. Also, it allows distinction between true infarctive crisis, infection, and fake symptoms. In 5 patients a rise in the level of alpha-H.B.D. above the patient's normal level was detected several days before the onset of symptoms, which suggests that there may be a "prodromal" phase.