Cryogenic vacuum valve with actuation times down to 50 ms.

We have conceived, built, and operated a cryogenic vacuum valve with opening and closing times as short as 50 ms that can be used in strong magnetic fields and across a broad range of duty cycles. It is used to seal a cryogenic Penning trap at liquid-helium temperature for long-term storage of highly charged ions in a vacuum better than 10-15 hPa from a room-temperature ion beamline at vacuum conditions around 10-9 hPa. It will significantly improve any experiment where a volume at the most extreme vacuum conditions must be temporarily connected to a less demanding vacuum during repeated experimental cycles. We describe the design of this valve and show measurements that characterize its main features.

[Renal cell carcinoma: unusual late metastases 14 and 23 years after kidney transplantation]. / Nierenzellkarzinom: Ungewöhnliche Spätmetastasierung 14 und 23 Jahre nach allogener Nierentransplantation.

HISTORY AND FINDINGS: An asymptomatic 70-year-old man was found to have a tumor in the region of the left adrenal gland, having undergone cadaveric kidney transplantation 23 years ago. Two years before this a right nephrectomy had been performed for a renal cell carcinoma. There was no left kidney because of agenesis. 14 years after the kidney transplantation a metastasis of the renal cell carcinoma was identified in the thyroid gland. After its resection no further metastases had been discovered. INVESTIGATIONS: Laboratory tests were unremarkable. But a tumor was detected in the left adrenal gland by computed tomography. DIAGNOSIS, TREATMENT AND COURSE: The left adrenal gland was successfully resected. Its histology confirmed a second metastasis of the renal cell carcinoma 23 years after renal transplantation, but no other metastases were found. CONCLUSIONS: Kidney transplantation can be successfully performed even in patients with pre-existing carcinoma. A late metastasis of a renal carcinoma may occur. Close long-term follow-up of the patients is therefore essential.

Analysis of secretory, immunostaining and clinical characteristics of human "functionless" pituitary adenomas: transdifferentiation or gonadotropinomas?

In this study, the central technique of in vitro culture has been used to further investigate whether LH/FSH-expressing, but clinically "functionless" pituitary adenomas are gonadotropinomas or whether their hormone secretion is due to transdifferentiation events. 664 "functionless" pituitary adenomas were examined for hormone secretion by in vitro culture and for hormone content by immunostaining. The results were correlated with the clinical findings. 40 % of the tumours (n = 263) secreted at least one of the gonadotropins alone, 8 % (n = 53) exhibited various patterns of anterior pituitary hormones, whilst the remaining 52 % of tumours were not associated with any hormone. In the secretory tumours, immunostaining revealed only a few scattered hormone-containing cells (5 to 15 %). Mild hyperprolactinaemia was observed in some cases, presumably because of pressure effects of the tumours. The majority of the patients suffered clear cut hypopituitarism (p < 0.05). Pre-operatively, gonadotropin hypersecretion was observed in 3 cases, but only one of these secreted hormones in culture. Interestingly, a higher proportion of tumours removed from patients with hypopituitarism showed secretory activity in vitro than those tumours removed from patients showing no hormonal dysfunction or hyperprolactinaemia. We conclude that the term "gonadotropinoma" to describe functionless pituitary tumours associated with LH and/or FSH secretion is a misnomer, because the presence of LH and/or FSH confirmed by in vitro methods in the present series is a result of only a few scattered cells. We suggest that primary pituitary tumour cells differentiate into a secretory type (transdifferentiation), possibly in response to altered serum hormone levels such as decreased steroids. Further work is required to identify the factors which trigger the altered cells' characteristics.

A Superconducting Magnet UCN Trap for Precise Neutron Lifetime Measurements.

Finite-element methods along with Monte Carlo simulations were used to design a magnetic storage device for ultracold neutrons (UCN) to measure their lifetime. A setup was determined which should make it possible to confine UCN with negligible losses and detect the protons emerging from ß-decay with high efficiency: stacked superconducting solenoids create the magnetic storage field, an electrostatic extraction field inside the storage volume assures high proton collection efficiency. Alongside with the optimization of the magnetic and electrostatic design, the properties of the trap were investigated through extensive Monte Carlo simulation.

Deeply bound 1s and 2p pionic states in 205Pb and determination of the s-wave part of the pion-nucleus interaction.

We observed well-separated 1s and 2p pi(-) states in 205Pb in the 206Pb(d,3He) reaction at T(d) = 604.3 MeV. The binding energies and the widths determined are B(1s) = 6.762+/-0.061 MeV, Gamma(1s) = 0.764(+0.154)(-0.171) MeV, B(2p) = 5.110+/-0.045 MeV, and Gamma(2p) = 0.321(-0.062)(+0.060) MeV. They are used to deduce the real and imaginary strengths of the s-wave part of the pion-nucleus interaction, which translates into a positive mass shift of pi(-) in 205Pb.

Intraoperative magnetic resonance imaging during transsphenoidal surgery.

OBJECT: The aim of this study was to evaluate whether intraoperative magnetic resonance (MR) imaging can increase the efficacy of transsphenoidal microsurgery, primarily in non-hormone-secreting intra- and suprasellar pituitary macroadenomas. METHODS: Intraoperative imaging was performed using a 0.2-tesla MR imager, which was located in a specially designed operating room. The patient was placed supine on the sliding table of the MR imager, with the head placed near the 5-gauss line. A standard flexible coil was placed around the patient's forehead. Microsurgery was performed using MR-compatible instruments. Image acquisition was started after the sliding table had been moved into the center of the magnet. Coronal and sagittal T1-weighted images each required over 8 minutes to acquire, and T2-weighted images were obtained optionally. To assess the reliability of intraoperative evaluation of tumor resection, the intraoperative findings were compared with those on conventional postoperative 1.5-tesla MR images, which were obtained 2 to 3 months after surgery. Among 44 patients with large intra- and suprasellar pituitary adenomas that were mainly hormonally inactive, intraoperative MR imaging allowed an ultra-early evaluation of tumor resection in 73% of cases; such an evaluation is normally only possible 2 to 3 months after surgery. A second intraoperative examination of 24 patients for suspected tumor remnants led to additional resection in 15 patients (34%). CONCLUSIONS: Intraoperative MR imaging undoubtedly offers the option of a second look within the same surgical procedure, if incomplete tumor resection is suspected. Thus, the rate of procedures during which complete tumor removal is achieved can be improved. Furthermore, additional treatments for those patients in whom tumor removal was incomplete can be planned at an early stage, namely just after surgery.

[Comparison of direct colony count methods and the MPN-method for quantitative detection of Listeria in model and field conditions]. / Vergleich von direktem Koloniezählverfahren und MPN-Methode beim quantitativen Listeriennachweis unter Modell- und Feldbedingungen.

In order to compare the plate count method for quantitating Listeria, as published in the "Official Collection of Testing Methods" in section 35 LMBG (L. 00.00-22), to an MPN-method for Listeria based on the same mediums, these two detection methods for Listeria were tested in three sets of experiments and a routine sample status evaluation. A pure broth culture of L. monocytogenes, artificially with L. monocytogenes contaminated ground meat, artificially contaminated and cold stored ground meat as well as 77 ground beef samples from Berlin retail food stores were used in the four trials. The detection limit of the MPN-method is about 66% lower than the plate count method allowing detection of a clearly greater number of Listeria-positive samples from naturally contaminated ground meat. The MPN-method yielded more Listeria spp.-positive samples (rel. 43%) and more L. monocytogenes-positive samples (rel. 21%) versus the colony count method based on the results from the field trial using ground beef samples from retail food stores in Berlin. Nevertheless the standardized colony count method is preferred over the MPN-method for routine use because of its slightly higher productivity and much smaller variation in the results. However, the MPN-method is preferable for epidemiological studies because of the significance of the lower detection level. The random sampling evaluation of ground beef from retail stores indicated that 39% of the samples were Listeria spp.-positive and 31% were L. monocytogenes-positive when using the colony count method. A total of 56% of the meat samples were found to be Listeria spp.-positive and 38% L. monocytogenes-positive when the MPN-method was used. Population levels ranged from 10 to 580 cfu/g (Listeria spp.-positive samples) and from 10 to 270 cfu/g (L. monocytogenes-positive samples) for the colony count method. The MPN-method yielded population levels of 3.6 to 930 MPN/g for Listeria spp.-positive samples and 3.6 to 150 MPN/g for L. monocytogenes-positive samples. L. monocytogenes strains isolated using the colony count method belonged to the following serovars: 1/2a (46%), 1/2b (13%), 1/2c (33%), 3b (4%) and 4c (4%). A similar serovar isolation pattern was found for L. monocytogenes-positive MPN-tubes. The most common serotype was 1/2a (43%), followed by 1/2c (32%) and 1/2b (14%). The serotypes 3c, 4b and 4c were all isolated 4% of the time.

Prospective evaluation of pretransplant blood transfusions in cadaver kidney recipients.

BACKGROUND: A beneficial effect of pretransplant transfusions on graft survival was demonstrated in the early 1970s. In the mid-1980s, however, retrospective studies showed that transfusions had lost their graft-protective effect in the cyclosporine era. During the last 10 years, deliberate transfusion pretreatment of transplant patients has been discontinued. METHODS: Within a collaborative project of 14 transplant centers, prospective recipients of cadaver kidney grafts were randomized to receive either three pretransplant transfusions or transplants without transfusions. RESULTS; The graft survival rate was significantly higher in the 205 transfusion recipients than in the 218 patients who did not receive transfusions (at 1 year: 90+/-2% vs. 82+/-3%, P=0.020; at 5 years: 79+/-3% vs. 70+/-4%, P=0.025). Cox regression analysis showed that this effect was independent of age, gender, underlying disease, prophylaxis with antilymphocyte antibodies, and preformed lymphocytotoxins. CONCLUSIONS; Transfusion pretreatment improves the outcome of cadaver kidney transplants even with the use of modern immunosuppressive regimens.

[Comprehensive range of services for general hospitals in the area of organ donation nearly doubles the number of donors in 2 years with a simultaneously economical process]. / Umfassendes Dienstleistungsangebot für Versorgungskrankenhäuser im Bereich Organspende verdoppelt nahezu die Spenderzahlen in zwei Jahren bei gleichzeitig ökonomischer Vorgehensweise.

To overcome the donor shortage, any potential donor resource must be detected. By establishing a professional service for peripheral hospitals, the numbers of donors available in small hospitals could be nearly doubled: 85% of all donors in our region come from nonuniversity hospitals. By using total quality management techniques, the time requirements for organ donation after confirmation of brain-death and given consent could be reduced to 6 h.

Raymond's syndrome following petrosal sinus sampling.

Inferior petrosal sinus sampling (IPSS) is used to evaluate the pituitary-dependency of Cushing's disease, and to predict the laterality of a microadenoma prior to transsphenoidal operation. A serious complication occurred in a 14-year-old boy: he suffered brain stem ischaemia with abducens nerve palsy and hemiparesis (Raymond's syndrome). The case prompted us to reconsider the indication for this investigation.

Acromegaly with 'normal' serum growth hormone levels. Clinical features, diagnosis and results of transsphenoidal microsurgery.

Among 216 consecutive patients with growth hormone secreting pituitary adenomas who underwent primary neurosurgical treatment at the University of Erlangen-Nürnberg, 8 cases of acromegaly with 'normal' basal growth hormone levels (less than or equal to 5 ng/ml) were seen. They all had the typical clinical features of acromegaly, exhibited an abnormal growth hormone secretion following an oral glucose load, and had markedly elevated somatomedin C levels. The GRH- and TRH/GnRH-tests were not found helpful in establishing the diagnosis. Neuroradiology could demonstrate a pituitary adenoma in all of the patients. Following transsphenoidal microsurgical resection of the tumours, growth hormone secretion during oral glucose tolerance testing was normalised in 7 of the 8 patients. Immunohistology and explant culture studies documented growth hormone secreting pituitary adenomas in all cases. The authors conclude that even the finding of repetitive 'normal' (less than or equal to 5 ng/ml) serum GH levels does not exclude active acromegaly and when the clinical diagnosis of acromegaly is suspected, dynamic endocrine testing may reveal abnormal secretion patterns of GH in these cases. Transsphenoidal microsurgical resection of a pituitary adenoma offers a good chance of clinical and endocrinological remission in these cases.

Long-term follow-up results in hormonally active pituitary adenomas after primary successful transsphenoidal surgery.

The long-term results of transsphenoidal surgery for hormonally active pituitary adenomas were assessed in 3 follow-up studies. Eight out of 50 patients with microprolactinomas developed a persisting postoperative re-increase of prolactin levels during an average follow-up period of 4.1 years. None of the 43 acromegalic patients who had achieved a suppression of growth hormone to below 2 ng/ml during an oral glucose load shortly after surgery relapsed. However, when the remission criterion was only based on basal growth hormone below 5 ng/ml 4 out of 61 patients showed a re-increase of growth hormone levels to persistently elevated values during an average follow-up period of 6.1 years. 14 out of 66 patients followed-up for an average of 8.2 years after successful primary microadenomectomy for Cushing's disease developed recurrent hypercortisolism as documented by an abnormal suppression of cortisol after oral low dose dexamethasone.

Estrophilin immunoreactivity versus estrogen receptor binding activity in meningiomas: evidence for multiple estrogen binding sites.

The existence of estrogen receptors in human meningiomas has long been a controversial issue. This may be explained, in part, by apparent heterogeneity of estrogen binding sites in meningioma tissue. In this study, estrogen receptors were determined in 58 meningiomas with an enzyme immunoassay using monoclonal antibodies against human estrogen receptor protein (estrophilin) and with a sensitive radioligand binding assay using 125I-labeled estradiol (125I-estradiol) as radioligand. Low levels of estrophilin immunoreactivity were found in tumors from 62% of patients, whereas radioligand binding activity was demonstrated in about 46% of the meningiomas examined. In eight (14%) tissue samples multiple binding sites for estradiol were observed. The immunoreactive binding sites correspond to the classical, high affinity estrogen receptors: the Kd for 125I-estradiol binding to the receptor was approximately 0.2 nM and the binding was specific for estrogens. The second, low affinity class of binding sites considerably influenced measurement of the classical receptor even at low ligand concentrations. The epidemiological and clinical data from patients with meningiomas, and the existence of specific estrogen receptors confirmed by immunochemical detection, may be important factors in a theory of oncogenesis.

Gonadal steroid receptors in meningiomas.

Oestrogen receptor (ER) analysis was performed in 70 meningiomas with an enzyme immunoassay, using monoclonal antibodies against human oestrogen receptor protein (oestrophilin) and with a sensitive radioligand binding assay, using 125I-oestradiol as radioligand. Low levels of ER immunoreactivity were found in tumours from 51% of patients, whereas ER binding activity was demonstrated in 40% of the meningiomas examined. In 8 (11%) tissue samples multiple binding sites for oestradiol were observed. The immunoreactive binding sites corresponded to the classical, high-affinity ER. In ligand binding studies, however, measurement of classical ER was considerably influenced by a second low-affinity, high-capacity oestrogen binding component even at low ligand concentrations. 3H-methylpromegestone and 3H-methyltrienolone, a synthetic gestagen and androgen, were used for concurrent determination of the progesterone receptor (PR) and androgen receptor (AR) binding activity. High concentrations of PR were detected in 53 (76%), whereas moderate levels of AR binding sites were demonstrated in 33 (47%) tumours. A positive correlation between ER immunoreactivity and AR binding activity is indicative for an oestrogen regulation of AR via the ER system. The presence of gonadal steroid receptors in a large proportion of meningiomas and the tendency for a dependence of receptor concentrations on the histological subtype could have implications for tumour therapy.

Correlation between estrophilin immunoreactivity and androgen receptor-binding activity in meningiomas.

Estrogen receptor (ER) analysis was performed with an enzyme immunoassay using monoclonal antibodies against human ER protein (estrophilin) in 70 meningiomas. [3H]methyltrienolone, a synthetic androgen, was used for concurrent determination of the androgen receptor (AR)-binding activity. Low levels of ER immunoreactivity were detected in 36 cases (51%), whereas moderately high AR-binding activity was demonstrated in 33 (47%) tumors. A positive correlation between ER immunoreactivity and AR-binding activity is indicative for an estrogen regulation of AR via the ER system. The presence of gonadal steroid receptors in a large proportion of meningiomas and the tendency for a dependence of receptor concentrations on the histological subtype could have implications for tumor therapy.