DNA measurement,proliferation markers,and other factors in pituitary adenomas

To assess the proliferative activity of pituitary adenomas, 36 surgically removed adenomas were studied by light microscopical parameters; mitotic count; expression of PCNA, Ki-67, cathepsin D, and EGF; and image cytometry. Three adenomas (9%) showed high, 11 (34%) medium, 17 (53%) moderate, and 1 (3%) low structural differentiation. In 10 adenomas (31%), no mitosis was observed. The average was 2.4 mitoses/100 HPF; the highest count was 7.1 mitoses/100 HPF. Eleven adenomas (33.3%) were PCNA-negative; in 20 adenomas (60.6%), between 0.05 and 3.9, and in 2 adenomas (6.0%), between 10.5 and 16.4 PCNA-positive nuclei were observed. Only a recurrent null-cell adenoma (9%) was Ki-67-negative. Three adenomas (9.1%) were EGF-negative, 28 (84.8%) showed up to 10% positive cells, and 2 (6.1 %) showed between 10 and 30% positive cells; 19 adenomas (68%) were cathepsin D-negative, including all endocrine-inactive adenomas. Half the adenomas had an euploid DMA stem line. Endocrine-inactive adenomas displayed a higher rate of euploid DNA stem lines than endocrine-active adenomas. The S-phase fraction varied between 2.97 and 28%, with a mean value of 14.4%. Half the adenomas showed an S-phase fraction of 11.65% or lower.     

Effects of benzodiazepine receptor partial inverse agonists in the elevated plus maze test of anxiety in the rat

The present series of experiments examined the effects of five benzodiazepine receptor (BZR) partial inverse agonists on the behaviour of rats on an elevated plus maze. The drugs were tested in a standard plus maze with 3-cm walls added to the open arms, as this has been shown to increase the sensitivity of the plus maze to anxiogenic-like drug effects (Jones and Cole 1995). The drugs tested were FG 7142 (0–100 mg/kg),-CCE (0–30 mg/kg), ZK 132 556 (0–100 mg/kg), ZK 90 886 (0–30 mg/kg) and Ro 15–4513 (0–30 mg/kg). In addition, to allow a comparison with previous studies, the effects of three reference substances, DMCM (0–2.5 mg/kg), pentylenetetrazol (PTZ; 0–30 mg/kg) and yohimbine (0–5 mg/kg), were also examined. These three reference compounds produced a dose-dependent reduction in the duration of open arm exploration and the total number of open arm entries, indicative of anxiogenic-like effects. DMCM produced significant effects at the doses of 1.25 and 2.5 mg/kg, PTZ at 30 mg/kg, and yohimbine at 5 mg/kg. The BZR partial inverse agonist FG 7142 (10, 30 and 100 mg/kg) also reduced the duration of open arm exploration and the total number of arm entries. The minimally effective dose resulted in a receptor occupancy of approximately 80%. Ro 15–4513 also produced anxiogenic-like effects, but only at a dose (30 mg/kg) that resulted in a receptor occupancy of approximately 95%. In contrast, the other BZR partial inverse agonists, ZK 132 553 and ZK 90 886, did not significantly reduce the duration of open arm exploration, even at doses that produced greater than 95% receptor occupancies.-CCE also did not reduce open arm exploration at any dose tested (0–30 mg/kg). The GABA shift, a biochemical index of intrinsic activity, indicates that these latter three compounds are more inverse agonistic than Ro 15–4513. In summary, these results demonstrate that not all BZR receptor partial inverse agonists have anxiogenic-like activity in the rat plus maze, and that the GABA shift, a biochemical index of intrinsic efficacy, does not predict which BZR partial inverse agonists are anxiogenic.     

Parasite communities of the Salzhaff (Northwest Mecklenburg, Baltic Sea). I. Structure and dynamics of communities of littoral fish, especially small-sized fish

The parasites of ten fish species, including four Gobiidae, three Gasterosteidae, two Syngnathidae, and one Zoarcidae from the Salzhaff region, Northwest Mecklenburg, Baltic Sea, were investigated in 1995 and 1996. As many as 36 parasite species, represented by diverse groups of helminths and protozoans as well as annelids and copepods, are found during 4 seasons in these hosts. By far the most abundant group is represented by digeneans, comprising 15 species, followed by 7 cestodans and 6 nematodes. With regard to component communities, 8 host-parasite combinations are core and secondary species with more than 40% prevalence in which generalists such as the digeneans Podocotyle atomon and Cryptocotyle concavum (in 3 hosts). C. lingua, Diplostomum spathaceum, and Acanthostomum balthicum, and the nematode Hysterothylacium are involved. Also, specialists such as Aphalloides timmi in Pomatoschistus microps as well as Magnibursatus caudofilamentosa and Thersitina gasterostei in Gasterosteus aculeatus attain high levels of prevalence. A comparison of different investigations reveals greater prevalence of allogenic and autogenic parasite species with 3 host cycles in the Rerik-Riff (free Baltic) and higher levels of prevalence of autogenic parasite species with 1 or 2 host cycles in the entire Salzhaff. The component communities of gobies from Dahmeshöved, Lübeck Bight, attain generally lower degrees of prevalence than those of the Salzhaff region. The infracommunities consist mostly of 1–3 parasite species per host specimen; this value is surpassed on occasion in P. microps (maximum 7 species) and in G. aculeatus (maximum 9 species, which may compete for 5 microhabitats in a host specimen). In this context the theory of empty niches propagated by some parasitologists is critically discussed and substituted by the assumption of variable niche widths. The seasonality of the more abundant parasites is either unclear – as in the case of C. concavum– or evident – as in the case of P. atomon, which prevail in early spring and summer, or A. timmi, which dominate in late summer, as do M. caudofilamentosa, which is absent in spring. The main causes of the infestation of fish hosts may be their ages and the availability of parasites due to the presence of intermediate hosts.     

Human phase I vaccine trials of 3 recombinant asexual stage malaria antigens with Montanide ISA720 adjuvant

Two phase I vaccine trials were conducted to test the immunogenicity and safety of a vaccine containing three recombinant malaria antigens from the asexual stage of Plasmodium falciparum. The three antigens are a fragment of MSP1 (190LCS.T3); MSP2 and a portion of RESA and were formulated in Montanide ISA720 adjuvant. These trials investigated the dose response of each antigen for eliciting both antibody and T-cell responses and the immunogenicity of a mixture of the antigens compared with the antigens injected separately. All three antigens elicited both antibody and T-cell responses. Strong T-cell responses were observed with 190LCS.T3 and RESA with stimulation indices exceeding 100 for peripheral blood leucocytes in some individuals. The antibody responses were generally weak. The human antibody responses observed with MSP2 in Montanide ISA720 were not significantly different from those obtained in an earlier trial which used MSP2 with alum as the adjuvant. No antigenic competition was observed: volunteers receiving a mixture of antigens had similar responses to those receiving the three antigens at separate sites. Tenderness and pain at the injection site were common over the first few days following immunization. In some volunteers, especially those receiving the highest doses tested, there was a delayed reaction at the injection site with pain and swelling occurring approximately 10 days after injection.     

Heterogeneity ofin vitro chemosensitivity in perioperative breast cancer cells to mitoxantroneversus doxorubicin evaluated by a microplate ATP bioluminescence assay

Summary Apart from clinical trials, mitoxantrone (MX) is rarely used in breast cancer (BC) due to the anticipated anthracycline cross-resistance. We have examined this drug versus doxorubicin (DOX) using data obtained fromin vitro microplate ATP tumor chemosensitivity assays (ATP-TCA) of BC cells which were derived from 55 chemotherapy-naive patients at time of primary surgery. Both drugs were tested at 6 different concentrations ranging from 6.25% to 200% peak plasma concentrationin vivo (PPC). Differences between DOX and MX observed for mean IC₅₀, IC₉₀, and a sensitivity index (SI) were not statistically significant.In vitro response rates were 44% for DOX and 52% for MX. 34 of 52 eligible assays (65%) showed comparable activity of both drugs whereas a lack of cross-resistance was observed in the remaining 18 (35%) tumors as indicated by differences for SI. Cumulative concentration-response plots of tumors respondingin vitro with a 50 percent or 90 percent tumor cell inhibition showed a strong dose-dependence for both DOX and MX at concentrations which normally can be achieved within clinical tumors (i.e. 6.25%-50% PPC). At higher concentrations, however, cytotoxicity of DOX and MX could not be improved by furtherin vitro dose escalation. Moreover, a substantial proportion of BC specimens (DOX: 48.1%; MX: 40.4%) did not experience a 90 tumor cell inhibition at 200% PPC. In conclusion,in vitro results obtained by ATP-TCA indicate that there is no cross-resistance between MX and DOX in a substantial proportion of BC patients. This may be clinically useful and suggests that combinations including MX should be tested in patients clinically resistant to DOX containing regimens. Since both drugs produced sigmoidal concentration-response curves, dose escalation beyond a certain point may not produce increased sensitivity.     

Small artery reconstruction with a new vascular prosthesis

In the Surgical Department of the University of Erlangen, 307 reconstructions in all areas of the arterial tree were performed with PTFE (GORE-TEX^®) grafts, of which 188 were performed in the femoral-popliteal and femoral-crural areas. Femoral-popliteal bypass grafts above the knee joint remained patent in 93% of the patients during an average follow-up time of 6.7 months. Below the knee joint, the patency rate was 85% during an average follow-up time of 5.6 months. In the proximal aorta, aorta-renal, and aorta-femoral areas, long-term results with the PTFE graft have been excellent.     

Single drug therapy for intractable epilepsy

Summary Single drug therapy with either phenytoin or primidone resulted in complete seizure control in 11 of 35 patients (31%) referred to an epilepsy clinic for treatment of uncontrolled chronic epilepsy with complex-partial seizures. Complete seizure control was associated with an increase in the mean plasma concentrations from 14 g/ml to 23 g/ml phenytoin and from 34 g/ml to 40 g/ml phenobarbitone with no change in the antiepileptic drug. Insufficiently low plasma concentrations of less than 11 g/ml phenytoin or phenobarbitone were measured at the first visit in 14 patients (40%). Non-compliance was admitted by eight patients (23%). Optimum single drug therapy is of considerable clinical value in intractable epilepsy with complex-partial seizures.

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Zusammenfassung Eine Monotherapie mit Phenytoin oder Primidon führte zur Anfallsfreiheit bei 11 von 35 Patienten (31%), die wegen schwerbehandelbarer psychomotorischer Anfälle eine Epilepsieambulanz aufsuchten. Anfallsfreiheit trat auf bei einem Anstieg der mittleren Plasmakonzentration von 14 g/ml auf 23 g/ml Phenytoin und von 34 g/ml auf 40 g/ml Phenobarbital. Ein Wechsel der Medikamente war nicht notwendig. Während der ersten Untersuchung wurden bei 14 Patienten (40%) zu niedrige Plasmakonzentrationen von weniger als 11 g/ml Phenytoin oder Phenobarbital gefunden. 8 Patienten (23%) gaben eine unregelmäßige Einnahme der Medikamente (non-compliance) zu. Eine konsequente Monotherapie ist von klinischem Wert für die Behandlung von schwerbehandelbaren Epilepsien mit psychomotorischen Anfällen.

     

Fourth swiss EEG-EP mapping meeting

Proceedings

Fourth swiss EEG-EP mapping meeting     

[125I] N6-p-hydroxyphenylisopropyladenosine,a new ligand for Ri adenosine receptors

Summary N⁶-p-Hydroxyphenylisopropyladenosine (HPIA) has been labelled with carrier-free Na[¹²⁵I] to very high specific activity (2,175 Ci/mmol) and used as an agonist ligand to characterize R_i adenosine receptors in rat cerebral cortex membranes. The binding is saturable, reversible, stereospecific and dependent on protein concentration. The specific binding at 37°C was of high affinity with an equilibrium dissociation constant K_D of 0.48 nmol/l and was saturable with 0.23 pmol of [¹²⁵I]HPIA per mg of protein. The rate constant of association, k₁, was 3.25×10⁸ l mol^–1 min^–1 and that of dissociation, k₂, 0.0110 min^–1 yielding a t_1/2 of 63 min. In competition experiments the (–)isomer of N⁶-phenylisopropyladenosine (PIA) was 16-fold more potent than the (+)isomer in competing for the binding sites. Specific binding was most effectively displaced by N⁶-cyclohexyladenosine (CHA, k_i=0.26 nmol/l), (–)PIA (k_i=0.33 nmol/l) and HPIA (k_i=0.52 nmol/l), whereas 5-N-ethylcarboxamidoadenosine (NECA, k_i-1.42 nmol/l) was less effective. The methylxanthines 3-isobutyl-1-methylxanthine (IBMX), theophylline and caffeine which have been classified as adenosine antagonists had k_i values between 5–34 mol/l. Binding of [¹²⁵I]HPIA was regulated by guanine nucleotides and divalent cations. The results indicate that [¹²⁵I]HPIA labels R_i adenosine receptors in rat brain membranes.     

Naloxone effects on β-endorphin,cortisol, prolactin,growth hormone,HVA and MHPG in plasma of normal volunteers

8 mg of naloxone were administered IV to 14 normal volunteers in a placebo-controlled, double-blind experiment. Plasma levels of -endorphin, cortisol, prolactin, growth hormone, HVA and MHPG were determined before and 45 min after administration. Naloxone elicited significant increases in cortisol and MHPG but did not change plasma levels of the other compounds. In an additional experiment on two subjects, 20 mg of naloxone caused elevations of -endorphin as well as of cortisol. This parallel increase indicates that the linkage between the secretion of -endorphin and ACTH/cortisol may be dose-dependent. The increase in MHPG is in agreement with the hypothesized association of noradrenergic hyperactivity and opiate withdrawal.