Allotransplantation of parathyroid tissue in humans is desirable for treating long-term hypoparathyroidism (e.g., after inadvertent removal of parathyroid glands during thyroid surgery). Until now, parathyroid allotransplantation was not used clinically because its advantages were outweighted by the need of immunosuppression. To overcome the immunogenicity of the tissue to be transplanted, we employed the method of microencapsulation; first tried in islet cell transplantation for experimental allotransplantation of parathyroid tissue. We have been able to achieve long-term success in a rat model. After isolation and tissue culture, tissue pieces from parathyroid glands of 280 Lewis rats were encapsulated in barium alginate and grafted into hypocalcemic DA rats. From the 7th to the 90th day after transplantation the recipient rats (DA rats) showed a normal serum calcium concentration. This is the first report of successful long-term survival and function of microencapsulated allotransplanted parathyroid tissue.

Animals↗

PubMedDate not supplied

Low microsatellite variation in laboratory gerbrils.

The Mongolian gerbil has become a model organism of increasing importance for the understanding of aging, epilepsy, the process of domestication or sociobiological questions. We report the development and characterization of the first nine polymorphic dinucleotide repeat loci in this species. Average observed heterozygosity and allele number of laboratory animals measured 0.136 (SE = +/-0.065) and 1.78 (SE = +/-0.278) compared to 0.761 (SE = +/-0.025) and 9.2 (SE = +/-0.57) found for a reference group of wild gerbils. The extreme low genetic variation observed in laboratory animals is caused by several severe population size bottlenecks due to the initial founder event and the later establishment of subpopulations. Reduced levels of allelic polymorphism in experimental animals hamper genetic mapping or parental studies. Therefore experiments relying on kinship analyses have to be carried out on wild animals. Estimates of genetic identity and parental exclusion were calculated as Pid = 2.8 x 10(-12) and Pex > 0.999 in wild gerbils. Laboratory gerbil strains show the expected high degree of genetic similarity. However, significant allele frequency differences (P < .001) between American and European gerbils at some microsatellite loci may still allow discrimination between breeding lines.

Animals↗

PubMedDate not supplied

Contrast-enhanced subtraction MR angiography in occlusive disease of the pelvic and lower limb arteries: results of a prospective intraindividual comparative study with digital subtraction angiography in 76 patients.

PURPOSE: The purpose of this work was to evaluate the feasibility and clinical use of MR angiography (MRA) for examining the pelvic and lower limb arteries in patients with arterial occlusive disease. METHOD: Seventy-six patients with clinical signs of peripheral arterial occlusive disease were included in the study. MRA was performed using a fast contrast-enhanced high-resolution 3D technique that covered the area from the distal abdominal aorta to the distal lower limbs in two examination steps. RESULTS: In all patients, diagnostic images comparable with those of conventional intraarterial digital subtraction angiography (DSA) could be obtained. No false-negative findings were seen in the iliac, femoral, or popliteal arteries. Ten to 16% of the mild stenoses and 6-14% of the severe stenoses, mainly in the crural vessels, were overgraded compared with intraarterial DSA. Particularly in patients with proximal severe obstructions or occlusions, the crural segments could be depicted more clearly due to decreased arterial runoff in conventional angiography. CONCLUSION: The consistency of the excellent depiction of the vascular territories of the distal aorta and the pelvic and lower limb arteries in a standardized setting suggests great potential for the use of MRA in the primary diagnosis of peripheral arterial occlusive disease.

Aged↗

PubMedDate not supplied

[Possibilities and limits of automatic detection of pathologic intracranial pressure waves with FFT].

Owing to the existence of "reserve spaces" varying individually in extent and expressed by the term compliance, space-consumption intracranial processes do not raise the intracranial pressure (ICP) primarily. Only when this compliance has been exhausted may ICP rise dramatically and may rapidly reach dangerously high levels. It has been shown in the past that "anticipatory" initiation of ICP-reducing measures--i.e. very early in the development of increasing mean ICP--may greatly benefit patient outcome. To recognize an imminent ICP crisis, the available compliance needs to be known. The classical method for determining this latter is the bolus test, which, however, has the disadvantage of being discontinuous and associated with the risk of infection. Another, less invasive and continuous, option is the recognition of pathological intracranial pressure waves. However, recognition of such patterns requires specialized knowledge, that is not widely available. Since, however, knowledge of the compliance is of general importance for intensive care, the idea of developing a PC-based automated system for the identification of pathological waves was followed up. During the course of our basic research effort, we investigated the suitability of the fast Fourier transformation (FFT) algorithm for this purpose. We were able to show that while the FFT is theoretically useful for the detection of pathological intracranial waves, its shortcomings in terms of its sensitivity to extraneous signals (noise) (of considerable importance for biological data handling) and errors in correctly estimating the amplitudes of pathological waves (of great importance for clinical evaluation) make FFT appear less than optimally suitable for this purpose.

Fourier Analysis↗

PubMedDate not supplied

[Stability of therapeutic outcome after child- and adolescent psychoanalytical therapy--a five-year catamnesis].

In the Heidelberg study about psychoanalytic therapy with children and adolescents 133 cases have been studied in a naturalistic design. Up to now results were published on the basis of assessments of experts only. This follow-up study has investigated the stability of therapy outcomes from the perspectives of different raters. For that outcome has been rated five years after the end of treatment by experts, parents and children themselves. Good outcomes have been stabile and have shown even after five years. Single variables showed further improvement in the time of follow-up, for example the social communicative impairment with parents. Thus the high rate of successful longterm psychoanalytic therapies with children and adolescents could be confirmed from different rater perspectives.

Adolescent↗

PubMedDate not supplied

Nude mouse xenografts as in vivo models for lung carcinomas.

Eighty-eight primary and secondary lung tumor specimens were subcutaneously transplanted into athymic nude mice. One third of all carcinoma specimens yielded tumor growth. Success rates were highest if fresh tumor pieces or fresh or frozen cell suspensions were implanted or injected. More than half of squamous cell and adenocarcinoma xenografts showed a lower degree of differentiation than the original tumor. The degree of dedifferentiation led to the diagnosis of large cell carcinoma by light microscopical criteria in 4 of these cases. All small cell carcinoma xenografts showed intermediate-cell type morphology irrespective of the cell type of the original tumor, and all large cell carcinoma xenografts showed features similar to the original tumor. Tumor latent periods were approximately twice as long during the first nude mouse passage than subsequent passages, and tumor doubling times remained stable during serial passages. We conclude that the large cell lung carcinoma subtype is a mixed bag of tumors and includes highly undifferentiated squamous cell and adenocarcinomas, that the small cell carcinomas remain in that histologic subtype during xenotransplantation, and that lung carcinoma xenografts display stable morphologic and kinetic features during serial xenotransplantation. Nude mouse xenografts may serve an in vivo model to study the biologic relationship of non-small cell lung carcinomas.

Adenocarcinoma↗

PubMedDate not supplied

Carcinoembryonic antigen as differentiation marker for small cell lung cancer in vitro and its clinical relevance.

Fifteen small cell lung cancer (SCLC) cell lines and 249 histopathological specimens from patients with SCLC were investigated for carcinoembryonic antigen (CEA) expression. Quantitative determinations of CEA in cell line homogenates correlated significantly (p less than 0.001) with L-DOPA decarboxylase (DDC) activities and population doubling times (PDT). Using monoclonal antibodies specific for CEA (BW 431/31) and crossreactive with non-specific crossreacting antigens (NCA) 55 and 95 (BW 250/183 and BW 374/14), the CEA-reactive moiety in SCLC was immunologically identified as CEA. In vivo studies demonstrated CEA by immunohistochemistry in 57% (141/249) of newly diagnosed SCLC. The presence of CEA and the degree of immunostaining did not correlate with clinical parameters.

Age Factors↗

PubMedDate not supplied

3D-computed tomography: a new method for the evaluation of fetal cranial morphology.

This study is the first presentation of three-dimensional computed tomography (3D-CT) for the in vitro evaluation of the prenatal human cranium. The study was based on CT examinations from 26 aborted normal fetuses between 10 and 25 weeks gestational age. Incremental coronal and transverse CT slices of 1 mm thickness and a threshold segmentation algorithm were used to generate 3D-CT reconstructions (surface-shaded display, SSD) of the cranial bones similar to their anatomical appearance. The threshold of the segmentation algorithm was selected after comparison of the 3D-CT images generated with varying thresholds and graphically reconstructed histological serial sections of particular sutures in five specimens. The variation of the segmentation threshold resulted in alterations of the bone sizes and suture widths. However, 3D-CT images allowed sensitive identification of the cranial ossification centers and accurate evaluation of the bone topography. Cutting and rotating procedures made it possible to evaluate all imaged bones in arbitrary views without disturbing superpositions, thus making isolated examinations of particular macroscopic sections of the specimens unnecessary. In conclusion, 3D-CT of the fetal cranium promises to be of considerable help in the evaluation of prenatal cranial development.

Algorithms↗