Integrated measurements of short-lived 222Rn progeny by rotating filters

The dependence of the risk from inhalation of radon progeny on their disequilibrium suggests that the measurements of the time-integrated concentrations of each of the short-lived radon progeny are necessary for complete risk estimations. This paper presents a method that, in principle, allows the determination of the integrated specific volume activities in air of each of the radionuclides 218Po, 214Pb, 214Bi, 212Pb, and 212Bi. The method employs thermoluminescence detectors positioned around uniformly rotating filters. Two prototypes that are suitable for practical applications are described and mathematical expressions for data processing are given. Experiments with these "rotating filter dosimeters" were conducted in atmospheres radiologically dominated by 222Rn progeny. The comparison between the results obtained by the proposed method and those given by simultaneously conducted series of instantaneous grab-sampling measurements support the conclusion that the method works for 222Rn progeny. The method can be experimentally extended for 220Rn progeny as well as for unattached fractions.     

A humanized antibody with specificity for hepatitis B surface antigen

A murine monoclonal antibody H67 was characterized for the binding specificity, which showed that H67 recognizes a disulfide-bond-dependent conformational epitope of common a antigenic determinant on the hepatitis B surface antigen. The result suggested that this antibody may have the potential of replacing hepatitis B immune globulin in the prevention of hepatitis B virus (HBV) infection. Therefore, we have constructed the humanized antibody HuS10 by grafting the complementarity determining regions and some framework amino acid residues of H67 onto the most homologous human antibody variable regions, 21/28 for heavy chain variable region and B1 and J kappa 2 for light chain variable region, followed by combining with human constant regions C gamma 1 and C kappa. The affinity of the HuS10 was the same as that of the H67, 8 x 10(8) x 10(8)M-1, and the HuS10 neutralized the in vitro infection of adult human hepatocyte primary culture by adr or ayw subtype of HBV. The neutralization assay showed that the HuS10 had approximately 2,000-times higher specific activity than commercially available polyclonal HBIG. These results suggest that the humanized antibody will be useful in the prevention or treatment of HBV infection.     

Two lectin-like receptors for alpha 1-acid glycoprotein in mouse testis

Three glycoforms of alpha 1-acid glycoprotein (AGP) were biotinylated to examine their binding in mouse testis by light microscopy. The transition from one stage to another in the spermatogenic cycle is marked with an appearance of a receptor for the Concanavalin A (Con A) non-reactive glycoform AGP-A in the cytoplasm of spermatocytes, young spermatids and Sertoli cells. This receptor disappears in the late stages of the spermatids. The Con-A intermediately reactive and the Con-A reactive glycoforms, AGP-B and AGP-C, showed weak reaction in the cytoplasm of spermatocytes, spermatids and Sertoli cells and, at the last stages in the spermatogenic cycle, a very strong reaction in the late elongated spermatids and the apical extensions of Sertoli cells. The interactions are lectin-like as confirmed by inhibition with simple sugars. In addition, the bindings were inhibited by steroid hormones. AGP-A was inhibited by testosterone, oestradiol and progesterone, while AGP-B and AGP-C were inhibited by mannose, GlcNAc, cortisone, aldosterone, oestradiol and progesterone. The receptors and the corresponding AGP glycoforms may be adhesion molecules between Sertoli cells and the spermatogenic cells and may have a function as a regulatory factor for spermatozoa development.     

Needle track seeding of primary and secondary liver carcinoma after percutaneous liver biopsy

Seeding of tumour in the needle track following percutaneous needle biopsy of liver neoplasms is rarely reported. We describe two such cases following the needle biopsy of an hepatocellular carcinoma and secondary colorectal carcinoma respectively. The risk of needle track recurrence of liver tumours should not be regarded as insignificant. The diagnosis of liver neoplasms may be achieved by non-invasive modalities, and their needle biopsy should be reserved for cases not amenable to surgical resection.     

Preoperative assessment and prediction of postoperative results in an artificial arterial network using computer simulation

A computer model has been developed that can be used to describe the human arterial system mathematically. It simulates the complex relationship of morphology and hydraulics in the vessel network. After entering patient data into a standard vessel model, the mean flow velocity, the flow direction, and the blood pressure at each specified point of the flow network can be calculated. The vessel picture can be altered and modified with the help of a graphic editor. Localized or diffuse stenoses, bypasses with simple or multiple anastomoses, end-to-end anastomoses, end-to-side anastomoses, etc., can be studied in terms of the hydraulic effects on the local situation or on the entire vessel system. Experimental results of ultrasonic mean flow data in vessel systems of leg and cerebral arteries of patients are compared with calculated values. The predicted and measured flow velocities show a mean difference of about 10% indicating that such a computer model may be successfully used in the optimal planning of bypass operations.     

Dynamics of somatic cell count (SCC) and differential SCC during and following intramammary infections

Somatic cell count is frequently used as an indicator of intramammary infections (IMI) in dairy cattle worldwide. The newly introduced differential SCC (DSCC) can potentially contribute to detection of IMI. The purpose of this study was to investigate the dynamics of SCC and DSCC after IMI. We used a data set with monthly samples from 2 Danish dairy herds through 1 yr, using bacterial culture to identify IMI. The dynamics of SCC and DSCC with regard to IMI were assessed at quarter level following new IMI with each of 3 defined pathogen groups, major, minor, or “other” pathogens, using general additive models. Both SCC and DSCC increased after IMI, with a more pronounced increase if major or other pathogens were detected compared with minor pathogens. We found that DSCC increased after IMI with other pathogens in both herds and, in herd 2, after IMI caused by major and minor pathogens. We also estimated the duration of increased SCC and DSCC when they exceeded a threshold, done separately for each pathogen group. Major pathogens had the longest-lasting effect in both herds for both SCC and DSCC. We conclude that the magnitude and duration of response of SCC and DSCC to IMI differs between herds and causative pathogens.