Dominant-negative interference of the transforming growth factor beta type II receptor in mammary gland epithelium results in alveolar hyperplasia and differentiation in virgin mice

Transforming growth factor (TGF)-beta1 and TGF-beta3 are normally expressed at high levels in the mammary gland during quiescence and at all stages of development, except lactation. Exogenously added TGF-beta1, -beta2, and -beta3 have been shown to regulate growth and differentiation of mammary epithelial cells in vitro and in vivo. TGF-betas signal through a heteromeric complex of type I and type II serine/threonine kinases. The type II receptor is necessary for ligand binding and growth suppression by TGF-betas. Deletions of the cytoplasmic domains of several kinase receptors known to function in multimeric complexes have been shown to act as dominant-negative mutations. To evaluate the role of endogenous TGF-betas in the growth and differentiation of the mammary gland in vivo, we have targeted expression of a truncated, kinase-defective TGF-beta type II receptor to mammary epithelial cells in transgenic mice using the mouse mammary tumor virus promoter/enhancer. Transgene expression was localized to the epithelial cells of terminal ducts and alveolar buds. At approximately 20 weeks of age, virgin female transgenic mice demonstrated varying degrees of mammary epithelial hyperplasia. Mammary glands from transgenic, virgin animals exhibited alveolar development and expression of the milk protein, beta-casein. The data suggest that impaired responsiveness in the epithelium to endogenous TGF-betas results in inappropriate alveolar development and differentiation in the mammary gland. We conclude that endogenous TGF-betas signal to the epithelium to maintain quiescence in the mammary glands of virgin animals.

Improved simulation system for routine cardiopulmonary exercise test equipment. Part III: A new cycle ergometer check system. ECSC Working Group on Standardization of Stress Test Methods

A new check system for cycle ergometers is described. The system consists of a device with a calibrated reference moment which connects to the crank axle of the ergometer to be controlled and exerts a known amount of force. It is equipped with a balance system that indicates whether the force applied corresponds to the preset resistance of the ergometer. The power actually produced by the ergometer is calculated by a mathematical formula. A mechanical and an electronic version are described. The accuracy of the calibrator was tested: mean error during constant pedal revolutions per minute (rpm) conditions was < 0.59% (SD < 0.31); in variable rpm conditions it was < 0.645% (SD < 0.378). An isoline diagram for rapid clinical use is also illustrated.

Interactions between cellular actin and human respiratory syncytial virus (HRSV)

Actin the main component of the cellular microfilament network, is present in human respiratory syncytial virus (HRSV) purified virions, as an internal component. This fact and the results of immunoprecipitation studies indicate that during HRSV infection in HEp-2 cells there are interactions between cellular actin and viral components, that can promote a transitory increase in the polymerization of synthetized actin, mainly of the beta isotype. This increased actin polymerization can be related with the formation of cytoplasmic extensions, that contain beta actin and viral particles observed in the HRSV infected HEp-2 cells. The formation of these structures may indicate that HRSV has developed an actin-based motility system similar to that described for other viral and bacterial systems.

Lactate infusion to normal rats during hyperglycemia enhances in vivo muscle glycogen synthesis

Both hyperglycemia and hyperinsulinemia stimulate whole body and muscle glucose disposal. To define the impact of increased lactate concentration (4-5 mM) on muscle glucose disposal during hyperglycemia, we studied anesthetized normal rats infused with either sodium lactate or sodium bicarbonate as control. Animals were studied under hyperglycemic clamp (13 mM) using [3-3H]glucose (study 1) and 2-deoxy-[1-3H]glucose (study 2) to assess glucose rate of disappearance (Rd), glycolytic flux (GF), glycogen synthesis, and glucose utilization index by different tissues. Moreover, in study 3, the effect of lactate on the pattern of plasma insulin response to hyperglycemia was evaluated. In study 1, lactate infusion resulted in an increased Rd (38.7 +/- 1.7 vs. 32.3 +/- 1.3 mg.min-1.kg-1; P < 0.01), which was explained by an enhanced rate of glycogen synthesis (23.0 +/- 1.7 vs. 14.7 +/- 1.2 mg.min-1.kg-1; P < 0.001), whereas GF was unchanged. In study 2, lactate-infused animals showed an increased 2-deoxy-glucose disposal and a stimulated glycogen synthase activity as well as an increased glycogen accumulation at the end of the study in several skeletal muscles. In study 3, lactate did not induce any change in either early or late insulin response to hyperglycemia. In conclusion, our results show that muscle glycogen deposition may be enhanced by elevated lactate levels under hyperglycemic conditions and support a role for lactate in the regulation of glucose homeostasis.

Modelling Bacterial Degradation of Organic Compounds with Genetic Networks

The bacterial degradation of organic compounds plays a crucial role in the biogeochemical cycles of the earth and in the clean-up of contaminated soils. The processes are carried out by bacterial consortia, rather than isolated strains, which are usually modelled by phenomenological kinetic equations which describe a fictitious, homogeneous bacterial species which mimics the behaviour of the consortium. An alternative modelling framework is presented here, where the bacterial consortia are considered as networks of genes interacting with other genes as well as with chemicals, which may be either introduced from outside or produced by bacterial metabolism. The model is based on an extension of the random Boolean network model of genetic networks, which makes use of continuous dynamical variables. Three different models are introduced, which differ in the way how they account for the existence of different species: (i) a single supercell model, where all the genes can interact strongly with each other; (ii) a graded interaction model, where genes interact strongly within a species, and weakly among different species; and (iii) a separate subsets model, where genes interact only within species. It is shown how this modelling framework is sound, as it is able to reproduce some of the generic behaviours of bacterial consortia, describing experimentally observed phenomena like population changes induced by contamination, and prey-predator dynamics.Copyright 1997 Academic Press Limited Copyright 1997 Academic Press Limited

Expression of a truncated, kinase-defective TGF-beta type II receptor in mouse skeletal tissue promotes terminal chondrocyte differentiation and osteoarthritis

Members of the TGF-beta superfamily are important regulators of skeletal development. TGF-betas signal through heteromeric type I and type II receptor serine/threonine kinases. When over-expressed, a cytoplasmically truncated type II receptor can compete with the endogenous receptors for complex formation, thereby acting as a dominant-negative mutant (DNIIR). To determine the role of TGF-betas in the development and maintenance of the skeleton, we have generated transgenic mice (MT-DNIIR-4 and -27) that express the DNIIR in skeletal tissue. DNIIR mRNA expression was localized to the periosteum/perichondrium, syno-vium, and articular cartilage. Lower levels of DNIIR mRNA were detected in growth plate cartilage. Transgenic mice frequently showed bifurcation of the xiphoid process and sternum. They also developed progressive skeletal degeneration, resulting by 4 to 8 mo of age in kyphoscoliosis and stiff and torqued joints. The histology of affected joints strongly resembled human osteo-arthritis. The articular surface was replaced by bone or hypertrophic cartilage as judged by the expression of type X collagen, a marker of hypertrophic cartilage normally absent from articular cartilage. The synovium was hyperplastic, and cartilaginous metaplasia was observed in the joint space. We then tested the hypothesis that TGF-beta is required for normal differentiation of cartilage in vivo. By 4 and 8 wk of age, the level of type X collagen was increased in growth plate cartilage of transgenic mice relative to wild-type controls. Less proteoglycan staining was detected in the growth plate and articular cartilage matrix of transgenic mice. Mice that express DNIIR in skeletal tissue also demonstrated increased Indian hedgehog (IHH) expression. IHH is a secreted protein that is expressed in chondrocytes that are committed to becoming hypertrophic. It is thought to be involved in a feedback loop that signals through the periosteum/ perichondrium to inhibit cartilage differentiation. The data suggest that TGF-beta may be critical for multifaceted maintenance of synovial joints. Loss of responsiveness to TGF-beta promotes chondrocyte terminal differentiation and results in development of degenerative joint disease resembling osteoarthritis in humans.

Improved simulation system for routine cardiopulmonary exercise test equipment. Part II: A new metabolic simulator system: practical applicability. The European Coal and Steel Community (ECSC) Working Group on Standardization of Stress-test Methods

The utilization in clinical practice of an improved metabolic calibrator was tested. The morphological characteristics and integration patterns of the signals were checked with a reference stress-test instrument and compared with physiological recordings. No significant differences were observed. Conversion formulae were developed to compare the calibrator's data with those produced by routine instruments. Simultaneous graphical representations of erroneous and reference signals and computer processing of data allowed on-line detection of even minimal sources of error in dynamic working conditions.

A new metabolic simulator system for routine cardiopulmonary exercise test equipment: technical specifications and validation. ECSC Working Group on Standardization Stress Test Methods

Modern stress-test instruments require non-steady-state calibration (i.e., during exercise) instead of calibration at rest (i.e., before use) in stable conditions. The purpose of the present study was to describe a new specific computer-controlled check system for stress-test instruments, which operates on the basis of physiological respiratory equations. It can produce rapid and automatic modifications of metabolic data, allowing breath-to-breath simulation. When connected to the stress-test equipment to be controlled, it makes it possible to identify discrepancies between preset and measured values. Systematic comparative measurements were performed using as reference two mass spectrometer-controlled analysers and a high-precision flow meter. Accuracy, trend and reproducibility in continuously changing conditions were very satisfactory.

Improved simulation system for routine cardiopulmonary exercise test equipment: introductory remarks. ECSC Working Group on Standardization Stress Test Methods

The instruments used in the evaluation of cardiorespiratory function employ extraordinarily fast and complex techniques: instantaneous ventilatory flow-volume transducer operate together with rapid CO2-O2 analysers, and are coupled to on-line cardiocirculatory monitors working in real time under the control of advanced software. It is clear that, with such powerful equipment, the calibrations currently made at rest before exercise are insufficient and must be accompanied by, or replaced with, methods capable of continuous (breath-to-breath) monitoring of the instrument's activity throughout the exercise period. Two new simulation and check systems were developed for the calibration and the continuous monitoring of exercise equipment. The former applies to metabolic determinations, the latter to the cycle ergometers employed to impose varying workloads in the implementation of specific protocols.

Regulation of differentiation by TGF-beta

Recent experiments in neural, skeletal, endothelial, and hematopoietic tissues have provided new insights into the way members of the transforming growth factor-beta (TGF-beta) superfamily regulate cellular differentiation. TGF-betas regulate the fate of multipotential stem cells instructively (in the neural crest) by regulating the expression or function of tissue-specific transcription factors, as well as selectively (in the mesenchyme) by regulating the expression of required growth factors and their receptors. During skeletal development, TGF-betas have unique functions and act sequentially to modulate chondrocyte and osteoblast differentiation. Responsiveness to TGF-betas changes as cells differentiate and evidence now suggests that changes in TGF-beta receptor profile may account for some of these differences. Drosophila and transgenic mouse models are now providing useful insights into mechanisms of TGF-beta action in vivo.

Effects of different levels of dietary zinc on the gilthead, Sparus aurata during the growing season

Gilthead were fed three diets. Diet A was the control diet, whereas diets B and C were supplemented with 300 and 900 mg Zn/kg, respectively. Fish fed with diet C, at the end of the experiment, showed the lowest weight. Zinc concentrations presented the higher values in gills, liver, and kidney. Muscle and brain had the lower mean values and showed a tight control of zinc levels. These results reinforce the hypothesis that zinc in the CNS should be strictly controlled in order to maintain the functional role of the metal. Significant differences in tissue zinc concentrations were obtained between fish fed different amounts of zinc, the metal concentrations being higher in tissues of fish fed diet C. The tissue decrease of zinc, found at the end of the experiment, may depend on a lower feed consumption or on different zinc requirements during the cold season. These changes, even if not univocal among the three diets, may be associated with the life cycle of fish. Furthermore, copper concentrations were little affected by the different concentrations of zinc in the three diets; liver and kidney presented the highest concentrations; liver showed a significant decrease in copper content at the end of the experiment. We conclude that: zinc concentrations of the diet may affect the gilthead weights and the tissual metal content; and zinc concentrations in the diets, depending on the growth rate, may be varied depending on the season.

pRb is necessary for inhibition of N-myc expression by TGF-beta 1 in embryonic lung organ cultures

The beta type transforming growth factors (TGF-beta) are potent inhibitors of epithelial cell proliferation, and data suggest that growth inhibition by TGF-beta 1 is mediated through suppression of Myc family genes in certain cell types. Indirect evidence has indicated that the product of the retinoblastoma gene (pRb) may also be involved in this pathway. Previously, we have shown that TGF-beta 1 inhibits branching morphogenesis and N-myc expression in mouse embryonic lung cultures. The purpose of this study was to determine the role of pRb in the inhibition of branching morphogenesis and N-myc expression by TGF-beta 1. Treatment with TGF-beta 1 was shown to inhibit development of lungs from homozygous Rb null (Rb−/−) and heterozygous null (Rb+/−) mouse embryos to the same extent as lungs from wild-type (Rb+/+) embryos. However, TGF-beta 1 treatment did not suppress N-myc expression in Rb−/− as it did in Rb+/+ embryonic lung explants as determined by in situ hybridization and quantitative RT-PCR. The effect of TGF-beta 1 treatment on N-myc expression in lungs from Rb+/− embryos was intermediate between that seen in Rb+/+ and Rb−/− embryos. Embryonic lungs derived from transgenic mice expressing the SV40 large T-antigen in lung epithelium under the control of the surfactant protein C promoter also showed inhibition of development in response to TGF-beta 1 treatment. The data demonstrate that pRb is necessary for TGF-beta 1 suppression of N-myc expression but not for TGF-beta 1 inhibition of branching morphogenesis; therefore, suppression of N-myc is not necessary for inhibition of branching morphogenesis by TGF-beta 1.

Influence of age and health on immune functions and trace elements

Apparently healthy elderly donors were screened according to a simple protocol that included clinical examination and the determination of hematological and biochemical values. This screening was performed to detect subclinical alterations which might interfere with immune responses and trace element status. The elderly were divided into two groups. The first group consisted of 22 (age 76 +/- 1 years) positively selected elderly (PSE), i.e. healthy subjects with no hematological and laboratory alterations, the second one comprised 13 (age 75 +/- 1 years) negatively selected elderly (NSE). Data were then compared with those obtained from 40 (age 35 +/- 2 years) healthy young controls. In both groups of elderly donors, plasma zinc levels were normal, while plasma copper concentrations were increased. Intracellular values of zinc and copper in mono- and polymorphonuclear cells from both groups of elderly were within reference limits. After in vitro activation, granulocyte chemiluminescence activity was impaired only in NSE. A decrement in the number of circulating CD3 lymphocytes and an increase in CD8d, CD57 cells were found in PSE, while NSE showed an increased number of CD3,DR cells and CD8d, CD57, CD8b,CD57 and CD16,CD56 positive cells. Our results indicate that only plasma copper levels were affected by age, whereas subclinical alterations in hematological or biochemical values appear to impair immune responses in the elderly.

Heavy metals in some species of waterfowl of northern Italy

Concentrations of heavy metals (zinc, copper, cadmium, and iron) were measured in several tissues (brain, gizzard, leg-muscle, heart, breast-muscle, intestine, liver and kidney) of moorhens (Gallinula chloropus), black-headed gulls (Larus ridibundus), and coots (Fulica atra) collected between autumn 1985 and spring 1989 in northern Italy. Cadmium concentrations in the liver and kidney of water-rails (Rallus aquaticus) and in five species of Anatidae collected also were measured. High mean (+/- SD) copper levels were detected in aerobic muscles such as heart (38 +/- 5 micrograms/g dry weight (DW)) and pectoral muscles (35 +/- 7 micrograms/g DW). Compared to other tissues, the iron content of brain was rather low and constant, with a mean value of 160 +/- 17 micrograms/g DW in moorhens, 157 +/- 60 micrograms/g DW in black-headed gulls, and 157 +/- 25 micrograms/g DW in coots. Iron concentrations in tissues of moorhens from the Reno River were significantly higher than those from the Sile River. Cadmium was detectable only in the liver and kidney; there was a linear relationship between cadmium levels in these two organs. The highest mean (+/- SD) cadmium concentrations were present in the kidney of black-headed gull (30 +/- 20 micrograms/g DW).

TGF beta 1 inhibits branching morphogenesis and N-myc expression in lung bud organ cultures

Lung buds isolated from 11.5 days post coitum mouse embryos survive and undergo branching morphogenesis in culture. This organ culture system was used to examine the role of TGF beta 1 and N-myc expression in lung branching morphogenesis. By 24 hours, TGF beta 1 reversibly inhibited branching morphogenesis in a concentration-dependent manner. N-myc is known to be expressed during embryonic development in epithelial cells involved in branching morphogenesis and homozygous null N-myc mice have defects in lung development. In the present study, TGF beta 1 was shown to inhibit the steady-state level of N-myc RNA 3- to 4-fold at 14 and 48 hours of treatment as measured by northern blot and RNase protection analysis. Suppression of N-myc expression in epithelium was confirmed by in situ hybridization. Since inhibition of N-myc occurred prior to the observed changes in morphology and previous genetic studies have demonstrated and important role for N-myc in lung development, a model is proposed in which TGF beta 1 inhibits tracheobronchial development by inhibiting expression of N-myc.

Transforming growth factor beta 1 suppresses transformation in hepatocytes by regulating alpha 1 beta 1 integrin expression

We previously reported that (a) treatment of the ras-transformed hepatocyte cell line NR4 with transforming growth factor (TGF) beta 1 suppresses many characteristics associated with the transformed phenotype including altered morphology, actin cytoskeleton reorganization, and anchorage-independent growth such that the cells more closely resemble the immortalized CWSV1 parent cell line; (b) transformed NR4 cells expressed significantly less alpha 1 integrin RNA than the immortalized CWSV1 cells; and (c) TGF-beta 1 treatment of NR4 cells stimulated the expression of alpha 1 and beta 1 integrin RNAs. In this report, the role of the alpha 1 beta 1 integrin in TGF-beta 1-mediated suppression of the ras-transformed phenotype was investigated. We determined that (a) the cell surface integrin that increased in response to TGF-beta 1 treatment of NR4 cells was alpha 1 integrin; (b) TGF-beta 1 altered the ability of NR4 cells to attach to collagen and laminin, the extracellular matrix components that interact with the alpha 1 beta 1 integrin receptor; (c) TGF-beta 1 treatment resulted in relocalization of the alpha 1 integrin on the NR4 cell surface; and (d) TGF-beta 1-mediated inhibition of anchorage-independent growth was blocked by the presence of alpha 1 integrin antibody. A cell line that overexpresses alpha 1 integrin was derived from NR4 cells; characterization of these cells indicated that they continued to express H-ras RNA but were less transformed than the parent NR4 cells. Specifically, they had an altered morphology, an organized actin cytoskeleton, and reduced ability to demonstrate anchorage-independent growth.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous neurolysis of the celiac plexus via the anterior approach with sonographic guidance

OBJECTIVE

The purpose of this study was to evaluate the usefulness of sonographically guided percutaneous neurolysis of the celiac plexus in patients with abdominal tumors or chronic pancreatitis in whom systemic analgesics were ineffective.

SUBJECTS AND METHODS

Neurolysis of the celiac plexus was performed in 38 patients, 34 with neoplastic disease and four with chronic pancreatitis. Under sonographic guidance, a 22-gauge needle was advanced by the anterior route to the area above the celiac plexus, and 30-40 ml of 50% alcohol was injected. Pain relief was assessed 1 week, 6 months, and 1 year after the procedure. Patients subjectively rated the pain after treatment as totally relieved, partially relieved, or unchanged.

RESULTS

At 1 week and at 6 months after treatment, pain was totally relieved in 61% of patients, partially relieved in 31%, and unchanged in 8%. After 1 year, pain was totally relieved in 39%, partially relieved in 52%, and unchanged in 9%. The complications observed were five cases of mild diarrhea and one case of retroperitoneal pain, which subsided with conservative treatment.

CONCLUSION

The anterior, sonographically guided approach appears to be as successful as other percutaneous techniques for neurolysis of the celiac plexus.

Stimulation of DNA synthesis and protooncogene expression in primary rat hepatocytes in long-term DMSO culture

We have previously described the use of a chemically defined medium (CDM) supplemented with epidermal growth factor (EGF) and dimethylsulfoxide (DMSO) to maintain long-term cultures of rat hepatocytes in a highly differentiated state. In this study, conditions necessary to stimulate high levels of DNA synthesis in hepatocytes in long-term DMSO culture were defined. Hepatocytes were maintained in culture for 20 days in CDM containing DMSO and EGF, insulin, and glucagon. EGF, insulin, and glucagon were then removed for 7 days. Readdition of EGF, insulin, and glucagon at day 27 (shiftup) was accompanied by a three- to sixfold increase in labeling index. If DMSO or dexamethasone (dex) + DMSO were removed at time of shiftup, the labeling index increased by 18- to 54-fold. TGF beta inhibited DNA synthesis stimulated by EGF shiftup, TGF alpha shiftup, or EGF shiftup in combination with removal of dex + DMSO. Stimulation of DNA synthesis was accompanied by a specific, sequential induction of protooncogene mRNA levels; c-fos mRNA was induced 23-fold at 0.5 h after readdition of EGF; c-myc mRNA was induced three- to four-fold by 0.5 h; TGF alpha mRNA was induced sevenfold by 8 h; K-ras mRNA was induced fourfold by 26 h. Changes in protooncogene expression paralleled changes seen in regenerating liver. When DMSO was removed for greater than 48 h, the cells flattened and spread out, chords of cells were no longer well defined, albumin mRNA levels decreased, and fibronectin, beta 1 integrin, and TGF beta transcripts increased.

[Intraoperative microbiological monitoring in abdominal aortic aneurysms in elective surgery. A review of the literature and the authors' personal experience]

Thirty-one patients, ranging in age from 57 to 78 years (mean 66), with the exclusion of cases with doubtful possible results, underwent abdominal aortic aneurysmectomy for asymptomatic AAA and had cultures from the aneurysmal wall and endovascular thrombus to identify possible microbiological source of future graft infection; 5 (16%) of 31 cultures yielded bacterial growth and the most common organism isolated was staphylococcus epidermidis. During an average follow-up of 15.4 months no graft infection was noted in patients with positive or negative aortic cultured. A literature review stresses the same disparity between positive cultures obtained at the aneurysmectomy and subsequent low graft-infection rate. It is concluded that the aneurysm wall itself does not represent an important source of early or late graft infection and it's suggested that the bacterial presence both in the wall and thrombus could be explained by an exogenous contamination at the operation time.

Transforming growth factor beta 1 partially suppresses the transformed phenotype of ras-transformed hepatocytes

The effect of transforming growth factor beta type 1 (TGF-beta 1) on DNA synthesis, anchorage-dependent and anchorage-independent proliferation, cytoskeletal organization, and gene expression in ras-transformed simian virus 40 (SV40)-immortalized hepatocyte cell lines was measured. An SV40-immortalized cell line (CWSV1), a control neo-transfected and selected cell line (N1), and neo+ras-transfected and selected cell lines (NR3 and NR4) were used for this study. CWSV1 and N1 cells do not grow in soft agarose and are not tumorigenic. The ras-transformed hepatocytes NR3 and NR4 grow in soft agar and are tumorigenic. TGF-beta 1 treatment did not inhibit DNA synthesis or anchorage-dependent growth in the SV40-immortalized hepatocyte cell line CWSV1 or in the ras-transformed hepatocytes. TGF-beta 1 treatment inhibited anchorage-independent growth, increased actin cytoskeleton organization, and altered the morphology of ras-transformed hepatocytes; that is, with regard to all three of these properties, TGF-beta 1-treated ras-transformed hepatocytes more closely resembled the immortalized parent cell line. c-Ha-ras and c-myc RNA levels were not altered in TGF-beta 1-treated NR4 cells. TGF-beta 1 treatment did alter expression of some genes in NR4 cells. The level of expression of alpha 1 integrin RNA was higher in CWSV1 cells than in NR4 cells and increased in NR4 cells when they were treated with TGF-beta 1. Similarly, the levels and profiles of integrins on the cell surface of CWSV1 cells compared to NR4 cells, as determined by cell surface protein iodination, differed and in TGF-beta 1-treated NR4 cells more closely resembled the surface integrin profile for CWSV1 cells.

Functional analyses of albumin expression in a series of hepatocyte cell lines and in primary hepatocytes

A series of simian virus 40-immortalized hepatocyte cell lines which are heterogeneous with regard to expression of albumin protein and RNA were characterized for their ability to transcribe the albumin gene. Nascent chain extension assay showed that albumin RNA levels in these cells were determined predominantly at the transcription level. The albumin promoter and enhancer sequences were fused to the bacterial chloramphenicol acetyltransferase gene; the ability of the resulting expression constructs to drive chloramphenicol acetyltransferase expression after transfection into these hepatocyte cell lines was measured. The activity of the albumin promoter and enhancer constructs in primary hepatocytes was also measured. The albumin promoter was expressed differentially in these cells; however, no correlation was found between the transcriptional efficiency of the transfected albumin promoter and endogenous albumin transcription. The albumin enhancer was functional in some but not all albumin-positive cells. The minimal albumin enhancer was mapped to a 330-base pair fragment extending from -9.94 kilobases (kb) to -10.27 kb; three elements within this fragment recently shown to be necessary for enhancer function in a murine hepatocyte cell line were also essential for albumin enhancer function in the rat hepatocyte cell line CWSV1. A transcriptional silencer was identified which could suppress the expression of the homologous albumin promoter and the heterologous herpes simplex virus thymidine kinase promoter. Preliminary analysis localized the albumin silencer between -11 and -12 kb. Our results suggest that multiple regulatory sequences may act cooperatively to determine efficient tissue-specific expression of the albumin gene.

[Corynebacterium G-1 infection: description of a case of endocarditis]

Here we report a case of Corynebacterium G1 group endocarditis following acute bpn in non immunodeficient host. The bacterial strain was isolated from the surgically removed heart valve. To our knowledge this is the first report of such an isolate. Recently recurrent peritonitis in CAPD were also ascribed to the same agent.

[Neurophysiology of the motoneurons of the external oculomotor nucleus in the waking cat]

The spontaneous and visually induced activity of abducens motoneurons has been recorded in the alert cat. Motoneurons were identified by their antidromic activation from the ipsilateral abducens nerve. All identified motoneurons appeared related to both the position and velocity of the eye in the horizontal plane, although distributed in a wide range. Neural time constants were also measured, showing a mean value similar to that of the mechanical time constant of the oculomotor plant. According to present results, abducens motoneurons of cats and monkeys are very similar, notwithstanding some differences in their activities during saccadic movements.

Electrophysiological and functional identification of different neuronal types within the nucleus ambiguus in the cat

Extracellular single neuron recording in nucleus ambiguus demonstrates the existence of different neuronal classes within its electrophysiological limits. Laryngeal motoneurons were identified by their antidromic activation from the recurrent laryngeal and vagus nerves. Interneurons were identified by their antidromic activation from the contralateral cervical spinal cord. Stimulation of the ipsilateral superior laryngeal nerve activated synaptically all laryngeal motoneurons recorded but not interneurons. Most motoneurons and all interneurons showed spontaneous discharges during the inspiratory phase of the respiratory cycle. A few expiratory motoneurons were also recorded. In addition to laryngeal motoneurons and interneurons vagal stimulation also activated a population of efferent neurons located in the nucleus ambiguus with firing patterns not related to respiration. Functional implications of described findings are discussed.

A new spirometric parameter in clinical pharmacology

Several functional parameters can be used to define respiratory dysfunctions. Many of these variables provide specific information about particular physiopathologic phenomena, but they seldom provide a general overview of the ventilatory function. Nevertheless, both pharmacologic and epidemiologic research need functional parameters that precisely specify the respiratory defect. The new parameter we discuss takes into account the variations in volumes as related to flow variations: it is the product of two traditional spirometric parameters (FEV1 X MMEF). This value gives information on the patient's capacity to exhale air from the lungs for a fixed variation of intrathoracic pressure as well as data on the acceleration pattern of the expired volume in 1 s, hence the name, acceleration index (AI). AI was used to predict bronchodilation in two groups of patients with severe airway flow limitations. On the basis of our findings three conclusions can be drawn. This new spirometric parameter provides an inexpensive and rapid means of obtaining a highly sensitive definition of the patient's respiratory dysfunction which is useful in screening patients. Applied to patients with severe airways obstruction, AI can be used to immediately predict the reversibility of air flow limitation and then to define the limits of the activity of bronchodilators. Finally, a basal value of AI below 1.000 l/s-1 indicates the probable irreversibility of the airways obstruction, regardless of drug or route of administration. Such cases suggest a prevailing picture of emphysema rather than reversible bronchospasm.

Pharmacokinetics and pharmacodynamics of a short- and long-acting theophylline medication (Theolair and Theolair retard) in normals and asthmatics. Part II: Lung function and side effects

Six normals and six patients with chronic obstructive lung disease were treated with a short- and long-acting theophylline (Theolair and Theolair retard). During treatment the lung function data of the patients showed an improvement on day 1, but no further improvement on days 4 and 7, despite the higher theophylline plasma concentration on these last days. There was no close correlation between the improvement of lung function and the theophylline plasma concentration, nor was there any difference between Theolair and Theolair retard as regards improvement of lung function. Side effects were negligible, and the theophylline plasma concentration was rather low. It seems advisable to use a higher dosage of the theophyllines and perhaps it is even better to combine them with other bronchodilators.

Reversibility prediction of chronic airways flow limitation by a new simple spirometric parameter

A new simple spirometric parameter for predicting the reversibility of bronchial obstruction is evaluated in two homogeneous groups of severe COLD patients. By combining FEV1 and MMEF, this index is practically the product of the volume expired in 1s and the corresponding flow at 50% of FVC which characterizes the emptying pattern. The parameter provides a useful method for verifying the patient's responsiveness to beta 2-bronchodilator drugs. The bronchial flow limitation depends more on the airways obstruction present than on the characteristics of the drugs administered. A threshold level for the new parameter was defined (1000 l/s); beneath this value responsiveness to beta 2 drugs must be considered practically negligible.

Terbutaline serum concentrations related to different lung function parameters and beta-receptor function

In eight asthmatic and six normal subjects serum terbutaline concentrations were correlated with changes in FEV1, MEF50%, Gaw, sGaw, and plasma cAMP concentrations after administration of 0.5 mg terbutaline subcutaneously, 5 mg orally, and an oral placebo. In asthmatics and normals the changes in serum terbutaline levels and plasma cAMP levels were closely correlated and in the same range. No change in lung function parameters was registered in normals, whereas in asthmatics a significant improvement was shown. In asthmatics all lung function parameters closely parallelled the changes in serum terbutaline concentrations and cAMP plasma concentrations, the FEV1 being the least variable lung function parameter. The maximal effect in FEV1 occurred 30-60 min after the subcutaneous dose and 2-4 h after the oral dose. The FEV1 improvement showed a linear relationship with the serum terbutaline concentration between 1.6 and 6 ng/ml. In contrast with theophyllines and anticholinergics, serum terbutaline concentrations showed a very low interindividual variance. Nevertheless it appeared that prediction of a certain improvement in lung function was not possible on the basis of the serum concentration. Since changes in plasma cAMP values after terbutaline therapy were similar in normals and asthmatics, the lung function improvement in the asthmatics suggests that if a beta-adrenergic defect exists, this must be mainly situated in the lung tissue.

[Field potentials induced in the ambiguous nucleus by stimulation of the recurrent and superior laryngeal nerves]

Field potentials in the ambiguous nucleus induced by stimulation of the recurrent, superior laryngeal and vagus nerves have been recorded in the anesthetized cat. Stimulation of the ipsilateral recurrent nerve induced a positive-negative-positive antidromic field potential in the ambiguous nucleus indicating a close-field organization of laryngeal motoneurons, which showed a preferential projection of their dendritic trees in dorso-medial and ventro-lateral directions. Superior laryngeal nerve stimulation induced the sequential synaptic activation of laryngeal motoneurons. Besides laryngeal motoneurons activation, stimulation of the vagus nerve also induced the antidromic invasion of a distinct population of efferent neurons with a latency longer than those of laryngeal motoneurons.

[Activity of axotomized motor neurons of the external oculomotor nucleus in the waking cat]

The spontaneous and the visual and vestibular induced activity of axotomized abducens motoneurons (ABD Mns) has been recorded in alert cats. Axotomy was carried out peripherally in the ocular orbit. ABD Mns were identified by their antidromic activation from the VIth nerve. Control Mns showed a clear relationship with eye position and velocity in the horizontal plane, whereas axotomized Mns showed a remarkable variability in their antidromic activation, a rapid fatigability during eye fixations and a decreased sensibility to eye velocity. Occasionally, axotomized Mns fired a short burst of activity before saccades in the off-direction. Functional involvements of described findings are discussed.

[Effects of distal axotomy on field potentials of the external oculomotor nucleus in the waking cat]

The electrophysiology of abducens nucleus antidromic field potentials from onset of peripheral axotomy up to reinnervation has been studied in the alert cat. Nerve section induced a reduction of 80% in the amplitude of the antidromic field potential. This reduction began from 2 to 5 days after axotomy and returned to control values from 20 to 30 days later, in parallel with recovery of oculomotor function. During the critical chromatolytic period, the latency of the antidromic potentials increased, while the amplitude of the antidromic field potential could be easily modified by adequate visual and/or vestibular stimulation. In contrast to control motoneurons, axotomized cells showed a noticeable variability in their activation latency, as well as a higher threshold for the antidromic invasion of the IS-SD compartments.

Intermittent positive pressure breathing administration of terbutaline: a dose response study

Eight patients with obstructive airways disease with a reversible component were treated with incremental doses of terbutaline by a Monaghan type nebulizer. Accumulative doses up to 3 mg were tolerated without significant side effects. Terbutaline appears to be safe and effective drug when administered by IPPB.

[A neurophysiological study of accesary abducens motoneurons in the awake cat (author's transl)]

The activity of abducens and accessory abducens motoneurons (Mns) has been recorded during spontaneous and vestibularly or visually induced eye movements in awake cats. Motoneuronal activity was also recorded during corneal reflexes induced by the excitation of trigeminal terminals in the orbit. Recorded Mns were antidromically identified by electrical stimulation of the VI nerve. Accessory abducens Mns showed a burst of activity in response to trigeminal stimulation, but they did not show any response in relation to horizontal, vertical and/or oblique eye movements. On the contrary, abducens Mns firing activities were related to the position and velocity of the eye in the horizontal plane, without showing any change in their firing patterns in response to trigeminal stimulation in the orbit.

Management of chronic obstructive lung disease

The management of chronic nonspecific lung disease (CNSLD) is a complex matter, influenced by different etiopathogenetic and physiopathological mechanisms. The most significant of these mechanisms have been revealed. Of the different function examinations the respiratory gas analysis appears to be particularly useful in obtaining detailed information. However, the choice of medication still remains of utmost importance. This paper presents a review of the selection criteria for antibiotics, bronchodilator drugs, theophylline derivatives, beta-sympathicomimetics, atropine corticoids, desensitizing substances together with the indication for a correct oxygen therapy.

[Respiratory functional evaluation in surgical patients]

Preoperative respiratory evaluation is examined in the light of factors likely to influence the conduct of the operation and its subsequent course. The methods required for this purpose are reviewed. Attention is first given to changes in specific respiratory components (alveolar exchange surface area, ventilation, diffusion and circulation) and their associated activities (chest mechanics, pulmonary circulation, motor nervous system), and those dependent on the type of surgery (lung, chest, abdomen, other parts). Next, the measurement methods available, the criteria for evaluating the data, and the criteria whereby candidates are selected for emergency surgery, surgery after thorough checking and extensive examination, general surgery, and chest surgery are explained. Lastly, the specific case of patients with typically respiratory diseases is discussed.

[Indications for and limitations of the exercise tests in respiratory physiopathology]

Following a review of the physiology of the subject, attention is concentrated on the significance of O2 consumption during exercise. The stages through which O2 passes prior to being used by the muscles are discussed, i.e. respiratory, cardiocirculatory, haematic, metabolic-tissue stages. Subsequently, the methods most commonly employed to evaluate the capacity of a patient to withstand an exercise test are illustrated and discussed. The various types of ergometers are covered first, the positive and negative features of each being indicated. The various tests are then described, these being subdivided according to their intensity into maximal and submaximal tests and, according to the load, into tests with constant load, increasing load, continuously growing load and variable load. The salient features of each are listed. The measurements (parameters, units, indices) that may be used and the standards to be observed on the basis of W.H.O. and EEC proposals are considered. After presenting the factors on the basis of which an exercise test may be appraised in relation to its purposes, the criteria for interpreting results in healthy and sick subjects are examined, with particular attention being paid to pneumo-patients and those with heart diseases. Particular stress is laid on the variations in certain basic parameters, such as Maximum withstandable effort, Oxygen debt, Maximum aerobic work, Ventilation break point and the behaviour of Haemogasanalytic, ECG, Cardiac output and Pulmonary artery pressure data in normal and pathological situations.

[Methods for the determination of VA/QC ratio]

Physiological considerations relevant to a general understanding of the question are put forward and the main methods used for determining the ventilation-perufsion ratio are described. Over-all methods offer generic evaluation of a change, particularly the method whereby the alveolus/arterial PO2 gradient is measured on straight lines expressing the different points of gas and blood respiratory exchanges, and that which measures the triple CO2, O2 and N2 alveolus/arterial gradient. Methods employed to evaluate the distribution of ratio changes are also explained: evaluation with CO2 labelled with 15O2, 133Xe, 13N2 and 85Kr, using pairs of scintillators, scanning detectors, gamma camera or special cuvettes, and analysis of respiratory He, Ar, O2, CO2, N2O and CHF2Cl at the mouth and inside the lung, using rapid analysers and single or multiple breath methods, or analysis of gas elimination coefficients. It is felt that measurement of the VA:Qc ratio is now within the capacity of all laboratories, so that qualitative, semi-quantitative and quantitative assessment can be made not only of the ability to ensure efficient alveolar exchange on the part of ventilation and circumation, but also of the presence of compensated changes, or the simultaneous presence of other alterations of various kinds, which cannot be readily detected by using conventional methods.

[Unequal ventilation: phenomenon of trapped helium]

The results of preliminary research designed to prepare a method for using mouth measurements to identify alveolar air trapping phenomena which cannot be detected by normal techniques are reported. With a present rapid thermoconductivity CO2/He analyser, it was shown that even after the completion of a standard He wash-out process, it is possible to reveal the persistence in the expiratory air of bronchiolostenotic patients of residual traces of inert gases alongside CO2 originating from normally ventilating sectors. The information obtained from the mouths of patients corresponds with the results of measurements taken inside the lung. Finally it is shown that with adequate therapy the trapping phenomenon may be reversed.