[Etiology and perinatal medical significance of prematurity below 1,500 g]. / Ursachen und perinatal-medizinische Bedeutung der Frühgeburten unter 1500 g.

305 preterm babies with birthweight below 1500 g were delivered at our centre between 1991 and 1994. Classification according to etiology shows that more than half (52.7%) of these deliveries had to be induced secondary to underlying fetal or maternal pathology. A more efficient tocolysis could have prevented up to one third of these deliveries (31.4%). The main cause of each preterm delivery was defined according to Whitfield's etiological classification. In decreasing order of frequency we found hypertensive disorders of pregnancy, multiple pregnancy, preterm premature rupture of membranes, preterm labour and vaginal bleeding in the third trimester. The majority of these deliveries (88.6%) were prenatal referrals, reflecting widespread regionalization of obstetric services in Switzerland. Nevertheless, 64 women (24.2%) with threatening preterm labour before the 32nd week of gestation had to be denied admission to our hospital because of shortage of neonatal intensive care beds, or had to be transferred from our hospital to another offering perinatal facilities during the study period (1991-1994). Acute lack of neonatal intensive care unit beds in Switzerland requires closer attention in the future.

Larch arabinogalactan for hepatic drug delivery: isolation and characterization of a 9 kDa arabinogalactan fragment.

Purified arabinogalactan [AG(37 kDa)] from Larix occidentalis is composed of repeating units of similar molecular weight and composition. A 9 kDa arabinogalactan [AG(9 kDa)] has been obtained in high yield from AG(37 kDa) either by autoclaving at 121 degrees C or by exposure to alkaline solution in the presence of sodium borohydride. The weight average molecular weight of AG(37 (kDa) was determined to be 37 and 38 kDa by intensity light scattering and sedimentation equilibrium, respectively. The weight average molecular weight of AG(9 kDa) was determined to be 9.1 and 9.5 kDa by intensity light scattering and sedimentation equilibrium, respectively. MALDI-TOF mass spectrometry yielded a molecular weight at the peak of the distribution of 8.3 kDa for AG(9 kDa). Both AG(37 kDa) and AG(9 kDa) exhibited narrow molecular-weight distributions (Mw/Mn approximately 1.2). AG(37 kDa) and AG(9 kDa) exhibit nearly identical 13C-NMR spectra, monosaccharide composition, and sugar linkages. It is proposed that AG(37 kDa) is composed of covalently bound subunits of AG(9 kDa). AG(37 kDa) and AG(9 kDa) bind isolated hepatocyte asialoglycoprotein receptor equally well. As a result AG(9 kDa) is a candidate for use in hepatocyte directed drug delivery and may be more desirable for such use than is AG(37 kDa).

[Tumor cell death as reflected by the SCC-antigen level?]. / Tumorzelltod im Spiegel der SCC-Antigentiter?

The serum levels of squamous cell carcinoma (SCC) associated antigen are related to the course of the therapy in 91 cases of advanced head and neck cancers. Without statistical significance the findings may lead to the following statements: 1. Serum levels below 2 ng/ml before treatment are not related to tumour growth. 2. Serum levels above 2 ng/ml before treatment are likely to be regarded as tumour-associated. 3. High and low level curves of not operated patients show a quantitatively different reaction to the course of a combined simultaneous radiochemotherapy. 4. Initially increasing serum levels under combined therapy may be interpreted as related to cell death or result of a production or proliferation stimulus. 5. High serum levels and low serum levels in tumour patients might be regarded as an expression of different biological activities in the tumour. 6. The comparison of the survival rates of high level tumours to low level tumours raises the question as to whether this different biological activity might be related to clinical malignancy.

[Squamous cell carcinoma-associated antigen (SCC) as a tumor marker in the initial diagnosis of carcinomas of the head and neck region. Results of a prospective study after 24 months]. / Das plattenepithelkarzinomassoziierte Antigen (SCC) als Tumormarker bei der Initialdiagnostik von Karzinomen des Kopf-Hals-Gebietes. Ergebnisse einer prospektiven Studie nach 24 Monaten.

The serum--SCC antigen levels of patients with head and neck tumors were studied prospectively to determine their value in the initial diagnosis of head- and neck-cancer patients. Serum concentrations above 2 ng/ml are considered abnormal. Preliminary results of the study after a 12-month period have been reported elsewhere (1). The final results of the study show an increased percentage (53%) of pathologic findings, mostly due to the increasing number of advanced stage tumors. High serum levels were found in 60% of the T4-tumors (Fig. 4a). Well differentiated carcinomas seem to be associated with the antigen more frequently than poorly differentiated tumors (Fig. 5). SCC antigen levels were examined as many as five times before the start of treatment (85 patients), and in one-third of those cases the differences between the serum levels exceeded 1 ng/ml. As far as 85% specificity is concerned, the ROC-curve shows a sensitivity of only 40% (Fig. 2) which, in addition to the fact that the antigen was most frequently found in cases of advanced tumors, indicates that the usefulness of the SCC antigen as a tumor marker for head and neck cancer must still be regarded as low.

A functionalized superparamagnetic iron oxide colloid as a receptor directed MR contrast agent.

We have synthesized a surface functionalized superparamagnetic iron oxide colloid whose clearance from the vascular compartment was inhibited by asialofetuin but not fetuin. Unlike other particulate or colloidal magnetic resonance (MR) contrast agents, the agent of the current communication is not withdrawn from the vascular compartment by cells of the macrophage-monocyte phagocytic system, as indicated by its selective increase in hepatic relaxation rates. Because of this we refer to this colloid as a hepatic selective (HS) MR contrast agent. At 20 mumol Fe/kg the HS MR agent darkened MR images of liver. The HS MR agent exhibited no acute toxicity when injected into rats at 1800 mumol Fe/kg. Based on these observations, surface functionalized superparamagnetic iron oxide colloids may be the basis of MR contrast agents internalized by receptor mediated endocytosis generally, and by the asialoglycoprotein receptor in particular.

[Squamous cell carcinoma antigen. Current clinical value of a new tumor marker in head and neck cancer; preliminary results of a prospective study after 12 months]. / Squamous cell carcinoma antigen (SCC). Derzeitige klinische Wertigkeit eines neuen Tumormarkers bei Kopf-Hals-Karzinomen, Zwischenergebnisse einer prospektiven Studie nach 12 Monaten.

The serum SCC antigen levels of patients with head and neck tumours are being studied in a prospective study to evaluate their clinical relevance. Concentrations above 2 ng/ml are considered to be abnormal. Preliminary results of the study after a 12-month period including 167 patients are reported: In only 28% of the patients with actual carcinoma of the head and neck the serum levels were pathological (Fig. 6), most commonly in oropharyngeal tumours (nearly 50%). The incidence of abnormal SCC-antigen concentration only rarely increased with increasing tumour extension (Fig. 7), but to a considerably greater extent in well-differentiated than in poorly or non-differentiated squamous cell carcinomas (Fig. 8). Tendencies, but no statistically significant correlation, were found between the Karnofsky index and the serum levels (Fig. 9) - as well as between the time of remission after successful tumour treatment and decreasing serum concentrations (Fig. 10). At the time of recurrence of the tumour, SCC-antigen serum levels had not been able to predict the clinical recurrence (Fig. 11). Since the assessment of SCC-antigen concentration is neither highly specific nor sensitive, the usefulness of this tumour marker test must be--at least according to the present state of the art--regarded as rather low.