Electrically evoked noradrenaline release from cultured chick sympathetic neurons: modulation via presynaptic alpha-adrenoceptors and lack of autoinhibition

Sympathetic neurons from twelve day old chick embryos were plated on polystyrol discs and kept in culture for five days. After incubation with 3H-noradrenaline the discs were transferred to small chambers and superfused. Electrical field stimulation (36 pulses at 3 Hz) increased the outflow of tritium. The evoked overflow of tritium was abolished in the absence of extracellular calcium and was diminished by about 90% in the presence of tetrodotoxin (1 mumol/l). The alpha 2-adrenoceptor agonist 5-bromo-6-(2-imidazolin-2-ylamino)quinoxaline (UK-14,304) caused a concentration-dependent decrease in overflow, whereas the alpha 1-adrenoceptor agonist methoxamine was ineffective at up to 1 mumol/l. The concentration-response curve of UK-14,304 was shifted to the right by the alpha 2-adrenoceptor antagonist yohimbine (0.03 mumol/l). Yohimbine on its own caused no significant change. The noradrenaline reuptake inhibitor cocaine (10 mumol/l) caused a small (20%) increase in evoked overflow. The results indicate that cultured chick sympathetic neurons possess release-modulating alpha 2-adrenoceptors and that the electrically induced overflow of transmitter occurs under conditions virtually free of autoinhibition.

Technical aspects of plasma leakage prevention in microporous capillary membrane oxygenators

A limiting factor in using microporous capillary membrane oxygenators (CMO) for long-term extracorporeal lung support is leakage. Application of heparin-coated CMO requires additional examination because leakage is probably caused by the temperature conditions of the gas, the blood and the circuit environment, and the surface tension phenomenon at the micropores. The authors designed a thermostatized box in which the temperature of flowing gas (Tg) and blood (Tb), and the interior temperature of the box (Ti) could be regulated independently. Tb was adjusted to the animal's body temperature, and Tg was kept about 2 degrees C higher to prevent condensation of the evaporated fluid from the blood side, through the micropores, into the gas phase. Ti was maintained between Tg and Tb. The saturated outlet gas could therefore condense only outside the box. This system was used during 5 days of venovenous bypass using a covalently heparin-bonded (Carmeda) CMO (Maxima, Medtronic) in four adult sheep. No plasma leakage occurred, the surface tension of condensate water remained constant, and the gas exchange capacity of CMO was unchanged.

Role of glucocorticosteroids in the regulation of pancreatic amylase synthesis

Both adrenalectomy and chemically induced diabetes mellitus cause a marked decrease of pancreatic amylase activity in rats, but it is unknown whether these effects are the result of a direct or indirect mechanism. The synthesis of various pancreatic enzymes has been studied in isolated pancreatic acini from sham-operated, castrated, and adrenalectomized animals as well as in animals that have been both adrenalectomized and castrated. Protein synthesis was measured by pulse labeling of acini with [35S]methionine followed by either trichloroacetic acid precipitation of total protein and counting or by SDS-PAGE and autoradiography, and additionally by in vitro translation of extracted pancreatic RNA using rabbit reticulocytes. Adrenalectomy resulted in a 70% reduction of amylase activity per milligram of acinar protein as a result of a decrease in amylase synthesis. This reduction in amylase synthesis is a consequence of a decrease in the amount of mRNA coding for amylase. After adrenalectomy, plasma concentrations of the following were reduced compared to controls: corticosterone to 0.45%, insulin to 11%, and glucose to approximately 66%. Addition of glucose to the drinking water caused an increase in insulin and plasma glucose, but this was not followed by an increase in amylase activity. We postulate that corticosterone directly regulates amylase synthesis in the rat pancreas.

Clinical response and survival according to estrogen receptor levels after bilateral ovariectomy in advanced breast cancer

Estrogen receptor levels were determined at the time of ovariectomy in 71 premenopausal women with advanced breast cancer. Three groups of estrogen receptor concentration were established: less than 10 fmol/mg cytosol protein (group 1), between 10 and 25 fmol/mg cytosol protein (group 2), and more than 25 fmol/mg cytosol protein (group 3). The frequency of clinical response to ovariectomy was low in group 1 (17.4%), high in group 3 (79.4%), and intermediate in group 2 (35.7%). Median survival was poor in group 1 (18.5 months) and better in groups 2 (33.0 months) and 3 (32.5 months). These results were independent of disease stage and neoplastic localization.

Complete remission after ovariectomy for advanced breast cancer correlated with estrogen receptor status and urinary androgen excretion

Our previous work showed urinary androgen excretion (A) as well as estrogen receptor (ER) to predict clinical response and survival after ovariectomy for advanced breast cancer. We here compare the complete responders with the partial responders to ovariectomy. The likelihood of CR (55% of responders) rather than PR was not strongly dependent on the location of metastases or on the ER/A status (though as noted previously there were no responses at all in the ER-/A- group), but CR did appear to increase survival.

Influence of adrenalectomy on pancreatic enzyme secretion

Both adrenalectomy and chemically induced diabetes mellitus cause a marked decrease of pancreatic amylase synthesis in rats. Diabetes is further associated with alterations of cholecystokinin (CCK)-stimulated enzyme secretion. Using isolated pancreatic acini prepared from adrenalectomized male rats, we investigated the effects of adrenalectomy on pancreatic enzyme secretion. CCK8-stimulated amylase secretion showed a typical biphasic dose-response curve in acini from both adrenalectomized and sham-operated animals with similar basal secretions, similar sensitivities to various CCK8 concentrations, but a statistically significant elevation of maximal amylase secretion after adrenalectomy. Receptor-binding studies with 125I-BH-CCK8 revealed an increase of binding to the high-affinity part of the CCK receptor in adrenalectomized rats. While carbachol-stimulated secretion showed no changes in maximal secretion rates, it did show a decrease in sensitivity in adrenalectomized animals with a statistically significant shift to the right of the dose-response curves. Competitive inhibition curves with 3H-N-methylscopolamine and carbachol as the competitive receptor agonist showed no differences in receptor binding between controls and adrenalectomized rats. We propose that complex alterations in hormone/neurotransmitter-stimulated pancreatic enzyme secretion are found in glucocorticoid depletion, explainable via a postreceptor defect in carbachol-stimulated secretion. The functional and binding data with regard to CCK are more difficult to explain.

Correlation between estrogen receptor levels and clinical response to ovariectomy in premenopausal women with advanced breast cancer

From 1974 to 1980, according to a controlled clinical trial, 66 premenopausal women with advanced breast cancer underwent bilateral ovariectomy (BO). Of the hormonal parameters evaluated, the present study deals with estrogen receptors (ER). The relation between the presence or the absence of ER and clinical response was evaluated, without considering their concentration in neoplastic tissue. The response was evaluated in relation to threshold values of 5 fmol/mg protein (considered at the time of the study the cut-off value of negativity and positivity) and 10 fmol/mg protein (recently found to be a more accurate cut-off value). The results of BO in relation to different receptor status showed an analogous response. Furthermore, the higher the receptor concentration, the better the response to BO, especially when the concentration was higher than 25 fmol/mg protein.

Conserved unpaired adenine residues are important for ordered structures of 5S ribosomal RNA. An infrared study of the secondary and tertiary structure of Thermus thermophilus 5S rRNA

An improved set of infrared calibration spectra for the determination of G X C and A X U base pairs leads to 32 +/- 3 G X C (+ G X U) and 4 +/- 1 A X U base pairs for Thermus thermophilus 5S RNA in the presence and absence of Mg2+. These results give further support for the consensus secondary structure of 5S RNA recently proposed by several groups. T. thermophilus 5S RNA shows, in the presence of Mg2+, a distinct two-step thermal melting of its ordered structure. Based on new data about the stacking dependence of infrared intensities of unpaired ribonucleotides the spectral changes of the low-temperature transition should be explained by melting of stacked arrangements of unpaired bases and/or non-standard base pairs. Striking is the reduction in A stacking, which is not related to the melting of A X U base pairs, indicating the importance of the mostly conserved unpaired adenines for the Mg2+ stabilized higher-order structures especially within internal loops of 5S RNA.

Prognostic Evaluation of Estrogen Receptors and Urinary Androgens in Ovariectomy for Advanced Breast Cancer

Eighty patients with advanced breast cancer were characterized by estrogen receptor (ER) status and by urine androgen (A) metabolites. After ovariectomy, patients with positive hormonal parameters were treated with hormonal therapy and patients with negative parameters were treated with chemotherapy. The results of the follow-up confirm that the survival is higher in patients with positive hormonal parameters (ER +, A+). In this group, the patients with increased urine androgen excretion (i.e. A+) apparently had a better long-term survival than ER + cases.

Laser Raman studies of the 5 S rRNA-protein L5 complex of rat liver ribosomes

The effects of ribosomal protein L5 on the conformation of 5 S rRNA in the 5 S rRNA-protein L5 complex extracted from rat liver ribosomes have been studied by laser Raman spectroscopy. A comparison of the spectra shows small protein-induced conformational changes in the 5 S rRNA, but most of the base-paired regions appear to be present in the complex with protein L5 as well as in the free 5 S rRNA. Furthermore specific interactions between 5 S rRNA and protein L5 are indicated. Cytosine (and/or uracil) residues in single-stranded regions and the N(7) of guanine are engaged in interactions with the protein as suggested by the Raman data.

[Gastroenterological endoscopy of the upper digestive tract from the surgical viewpoint]

On the basis of an EDP-supported analysis of data which were got in 1,808 endoscopized patients general problems are treated, basing on experiences of a surgicoendoscopic working team. Besides statements concerning the structure of age and sex, indicating signs as well as complication rate the authors adopt a definite attitude to problems of endoscopic care, documentation and training.

[Comparison of radiotherapy and surgery in the management of cervical cancer in stages Ib and II]

In the years 1971-76 we have treated 243 stage Ib cancers of the cervix. 104 (45.9%) were submitted to a radical surgery in the form of a classical Wertheim-Meigs operation in 32 of them, whilst in the other 72 lymphadenectomy was extended to the lumbar-aortic chains. When feasible, all the operated cases were submitted to a postoperative radiumtherapy on the vaginal vault and to external irradiation if N+ at histological examination. 114 cases (46.9%) were submitted to a complete course of radiotherapy. The remaining 25 cases (10.3%) were submitted to a preoperative radiumtherapy plus radical surgery. The 5-year NED survival was 89.5% in the surgical group, 93.0% in the radiotherapy group and 91.1% for the patients submitted to a preoperative radiumtherapy. In the time interval considered the stage II cases were 89. 14 (15.7%) were operated upon, 66 (74.2%) were treated with a complete course of radiotherapy and 9 (10.1%) were submitted to a preoperative radiumtherapy plus radical surgery. The 5-year NED survival was respectively 83.8%, 67.1% (only for proximal-stage II cases) and 100.0%. Radiotherapy is equivalent to surgery for the treatment of the stage Ib cervical cancers. On the contrary several arguments claim a combined therapeutic approach in the treatment of the stage II cases.

[Comparison between the diagnostic findings of esophago-gastro-bulboscopy and standard radiographic diagnosis]

On the basis of a computer-supported evaluation of the data of 1,808 patients who underwent endoscopy (endoscopy of the superior alimentary tract) the comparison of X-ray-findings and findings of the endoscopy could be made in 887 patients. For 124 patients with an oesophageal and gastric tumour, respectively, and for 146 patients with a gastroduodenal ulcer a control of the findings by superordinate parameters (findings of operations and post-mortem examinations) are present. The result was an accordance between 90 and 98%. The accordance of the evidence of the two methods varies depending on the group of diagnosis. For the oesophageal carcinoma it is 90%, for the gastric carcinoma ca. 77%, for the ventricular ulcer and the duodenal ulcer in every case 70%, while the X-ray diagnosis "no abnormality discovered" could be endoscopically confirmed only in 56%. From this result necessary conclusions concerning the further concept of the diagnosis of diseases of the superior alimentary tract.

[The degree of reliability in endoscopic diagnosis]

The histological ascertainment of pathological lesions is one of the most essential advantages and tasks of endoscopy. Of 1,808 patients who underwent endoscopy (oesophago-gastro-bulboscopy) in 620 present results of cellular investigations we could compare with the macroscopic estimation of the findings. 222 times out of 288 patients (77.1%) the diagnosis made--inflammation--could be histologically confirmed. Of 190 malignant tumours the result of this investigation is present for 172 patients. In 29.1% a histological confirmation (exclusive biopsy) could at first not be achieved. Macroscopic estimations of the findings alone are not sufficient, the histologic verification is not in every case at once achievable.

Two distinct conformations of rat liver ribosomal 5S RNA

Three different conformers of rat liver 5S ribosomal RNA were investigated by partial nuclease cleavage technique using S1 nuclease and cobra venom endoribonuclease (CVE) as conformational probes. Urea-treated and renatured 5S RNA co-migrate on non-denaturing gels, but exhibit distinct differences in their nuclease cleavage patterns. The most prominent differences in S1 nuclease and CVE accessibility of these conformers are located in region 30-50 and around nucleotides 70 and 90. The third form of 5S RNA with higher electrophoretic mobility was generated by EDTA treatment. The cleavage patterns of this 5S RNA conformer are similar to that characteristic for the renatured 5S RNA. The results demonstrate the difference in secondary structure and possibly different tertiary base-pairing interactions of 5S RNA conformers.

Universal structural features of prokaryotic and eukaryotic ribosomal 5S RNA derived from comparative analysis of their sequences

An extensive comparative analysis of more than fifty available sequences of ribosomal 5S RNA has been made. Both for prokaryotic and eukaryotic 5S RNA a generalized secondary structure is presented which is similar to that suggested by Nishikawa and Takemura modified in few positions only. Both generalized secondary structures contain five main helical regions and a high base-pairing content of about 65 +/- 5%. The general structural architecture of prokaryotic and eukaryotic 5S RNA molecules appears to be very similar with minor modifications within particular subgroups of organisms. Conserved and semiconserved nucleotides are accumulated in the single stranded parts of 5S RNA. Functional importance was suggested for some of these regions; other short conserved nucleotide stretches may be involved in the folding of 5S RNA molecules. In particular, we propose a tertiary base-pairing interaction between the universal invariant GUA sequence (positions 76-78 and 75-77 in prokaryotic and eukaryotic 5S RNA, respectively) and the complementary conserved CPuU sequence (positions 38-40 and 36-38) in a parallel manner. A molecular model of the 5S RNA of human KB cells was constructed, which verifies the proposed tertiary interaction, probably stabilizing the two neighboured helices E and D and a stacking arrangement of the bases in the sequence positions 67-108 (and 70-106) in eukaryotic (and prokaryotic) 5S RNAs, respectively.

Temperature behaviour of human serum albumin

Structural alterations of albumin, their dependence on concentration and the role of free --SH groups at thermal denaturation, as well as the reversibility of thermally induced structural changes, were studied. Application of various physical methods provides information on a series of structural parameters in a major concentration range. Apart from changes of the helix content, heat treatment gives rise to beta structures which are amplified on cooling and which are correlated with the aggregation of albumin. With rising temperature and concentration the proportion of beta structures and aggregates increases. At degrees of denaturation of up to 20% complete renaturation is possibly in every case. The structure content is concentration-dependent even at room temperature. It may be that intermolecular interactions induce additional alpha-helix structures which are less stable, however, than the ones stabilized by intramolecular interactions. Unfolding of the pocket containing the free --SH group of cysteine-34 enables disulphide bridges to be formed leading to stable aggregates and irreversible structural alterations. Through binding of N-ethymaleimide to free --SH groups, which blocks the formation of disulphide bridges, it is possible to prevent aggregation and irreversible conformational changes. At temperatures below 65--70 degrees C, oligomers are formed mainly via intermolecular beta structures.

[Clinico-endoscopic problems in malignant changes of the gastric stump]

The authors give a report on occasional difficulties concerning the radiological and endoscopic clarification of the malignant changes at the gastric stump after treatment of resection. Four relevant cases are stated and explained. The endoscopy (glass fibre gastroscopy) together with the biopsy is at present the most reliable method for the diagnosis of the pathological processes in the remaining part of the stomach. A regular endoscopic and radiological control of patients with gastric resection is desirable.