Comparison of the GAGA factor genes of Drosophila melanogaster and Drosophila virilis reveals high conservation of GAGA factor structure beyond the BTB/POZ and DNA-binding domains

As a member of the trithorax-group, the Trithorax-like (Trl) gene of Drosophila melanogaster contributes to the expression of homeotic genes and many other genes. Trl encodes different isoforms of the GAGA factor which is thought to act as an "antirepressor" of transcription by remodelling chromatin structure and thereby rendering control regions accessible for transcriptional activators. A more global role of the GAGA factor in chromatin structure and function is suggested by various phenotypes of Trl mutations, such as modification of position effect variegation. To better define the molecular basis of these pleiotropic effects, we cloned cDNAs encoding the GAGA isoforms of D. melanogaster and a distantly related species, D. virilis. We also characterized the genomic organization of both the D. melanogaster and D. virilis genes, and analysed the expression patterns of isoform-specific mRNAs. The D. virilis GAGA isoforms show high similarity to their D. melanogaster counterparts, particularly within the BTB/POZ protein-interaction and the zinc finger DNA-binding domains. Interestingly, conservation clearly extends beyond the previously defined limits of these domains. Moreover, the comparison reveals a completely conserved block of amino acid residues located between the BTB/POZ and DNA-binding domains, and a high conservation of the C-terminus specific for one of the GAGA isoforms. Thus, sequences of as yet unknown functions are defined as rewarding targets for further mutational analyses. The high conservation of the GAGA proteins of the two species is in accord with the nearly identical genomic organization and expression patterns of the corresponding genes.

[Explanatory factors for length of stay in the postoperative intensive care unit]

OBJECTIVES

Because of the increasing role of post-anaesthesia care in anaesthetic activity, the explicative value of various factors on post-anaesthesia length of stay (POLS) was tested.

STUDY DESIGN

Retrospective study.

PATIENTS

Population of 38,655 patients admitted to the post-anaesthesia care unit (PACU) between 1990 and 1994.

METHOD

Multivariate analysis (semiparametric Cox model) of POLS.

RESULTS

Overall 71% of the patients stayed less than four hours in PACU. Average POLS did not vary with years. Eleven variables were related to POLS, with an odds-ratio (OR) between 0.75 and 0.77 (negative link) or between 1.22 and 2.77 (positive link). A comparison of the OR for years 1990 to 1994 indicated major variations for the following three variables: neurosurgery, mechanical ventilation in PACU, low occupancy rate in the PACU at the time of discharge.

CONCLUSION

POLS are linked with various factors whose changes in explicative value can be analysed chronologically. However, other methods remain necessary in order to evaluate the impact of organisational modifications, as the introduction of objective criteria for discharge.

Conversion of neuronal growth cone responses from repulsion to attraction by cyclic nucleotides

Nerve growth is regulated by attractive and repulsive factors in the nervous system. Microscopic gradients of Collapsin-1/Semaphorin III/D (Sema III) and myelin-associated glycoprotein trigger repulsive turning responses by growth cones of cultured Xenopus spinal neurons; the repulsion can be converted to attraction by pharmacological activation of the guanosine 3',5'-monophosphate (cGMP) and adenosine 3',5'-monophosphate signaling pathways, respectively. Sema III also causes the collapse of cultured rat sensory growth cones, which can be inhibited by activation of the cGMP pathway. Thus cyclic nucleotides can regulate growth cone behaviors and may be targets for designing treatments to alleviate the inhibition of nerve regeneration by repulsive factors.

Monitoring intensive endurance training at moderate energetic demands using resting laboratory markers failed to recognize an early overtraining stage

BACKGROUND

Aim was to answer the question whether resting laboratory parameters are suitable for monitoring intensive endurance training at moderate energetic demands. This was designed since markers of overtraining at high energetic demands, e.g. mild anemia, leukopenia, iron deficiency, reduced serum albumin, glucose, triglyceride, triglyceride-rich cholesterol (LDL, VLDL), free fatty acid, increased plasma noradrenaline levels, and decreased basal catecholamine excretions were recommended.

METHODS

A prospective 6-wk, 6-dys/wk intensive steady state and interval cycle ergometer training of 40-60 min/dy was performed. Total load was about 6-time pretraining activities followed by a 2-wk, 2-hour/wk regenerative training period. Six recreational athletes (VO2max 51.5 +/- 4.5 ml.kg-1.min-1) participated and finished the study. A large pattern of resting hematological, blood-chemical, and hormonal parameters was tested regarding suitability for monitoring overtraining.

RESULTS

After 3 wks, submaximum and maximum performance were significantly increased, stopped improving between wk 3 and 6, or deteriorated. No supercompensation occurred after regeneration, but a decrease in work output. Lack of progression and supercompensation, and decreased maximum work output indicate a critical stage in the training process.

CONCLUSIONS

All examined resting laboratory parameters failed to reflect this critical stage except for a significant decrease in serum glucose, ferritin, and free fatty acid concentrations.

Utero-ovarian interaction in the regulation of reproductive function

The physiological regulation of fertile reproductive cycle in mammals depends on interactions between hypothalamus-pituitary, ovarian and uterine stimuli. Over the past 20 years, much has been learned about the interrelation between the affluent and effluent lymph and vascular drainage in and around both ovarian and uterine tissues. An essential feature in the regulation of the fertile cycle is the functional status of the ovary, particularly the corpus luteum. During the time of implantation and the early pregnancy, an active corpus luteum is essential. As human chorionic gonadotrophin (HCG) is important in the maintenance of the corpus luteum, we investigated if it was produced by the cyclic endometrium. Immunohistochemical and in-situ hybridization reactions were performed but neither identified the presence of HCG during the proliferative phase. Positive staining and beta-human chorionic gonadotrophin (beta-HCG) mRNA were observed during the secretory phase in the glandular cells of the endometrium. The results were confirmed by Western blotting of secretory phase endometrium extracts and assessment of the functional secretory capacity of primary endometrial cultures. Polymerase chain reaction (PCR) investigations showed a positive result in the secretory phase. We postulate that, based on the very close morphological interrelation between the uterus and the ovary, the beta-HCG of the endometrium is the primary factor for the maintenance of the corpus luteum and early pregnancy.

Convergent effects of growth factors, hormones, and fibronectin are necessary for the enterocyte differentiation of a colon adenocarcinoma cell line (HT29-D4)

The aim of this work was to show in serum-free medium a convergent effect of physiological factors and extracellular matrix proteins on the differentiation process of enterocytes by taking as a model the HT29-D4 clone that has the feature of differentiating when subcultured in fetal bovine serum glucose-free medium. We show that triiodothyronine (T3) as well as insulin promotes limited cell growth and differentiation, whereas fibronectin or bovine serum albumin (BSA) induces cell growth and a low level of differentiation. However, insulin, T3, fibronectin, and BSA together with epidermal growth factor and transferrin promoted satisfactory growth and enterocyte morphology with epithelial electrophysiological properties in HT29-D4 cells. With these factors adequate protein targeting was achieved since cells apically expressed the carcinoembryonic antigen, and basolaterally transferrin and insulin receptors, beta 1 and alpha v beta 6 integrins, talin, vinculin, and focal adhesion kinase (FAK). Talin, vinculin, FAK, and alpha v beta 6 integrin, the fibronectin receptor, were clustered in focal contacts, which agrees with a possible role of fibronectin in final cell growth, the latter process mediating the final phase of differentiation. This level of differentiation can be maintained for a long time. Thus HT29-D4 cells appear to be a suitable model to study the implication of integrins in the differentiation process of human enterocytes.

HCG secretion by peripheral mononuclear cells during pregnancy

Peripheral mononuclear cells (MNC) in culture release a biologically active hCG. This effect is detectable during pregnancy with a maximum between the 9th and 16th wk. Peripheral MNC already secrete hCG between the 7th and 11th d after embryo transfer. The secretion of hCG is activated by the PKC-activator TPA. TPA induces hCG release into the medium, thus causing a decrease in intracellular hCG content. In contrast, db-cAMP inhibites hCG secretion into the medium. Protein synthesis inhibitors of transcription and translation suppress the production and secretion of hCG. Peripheral natural killer (NK) cells (CD56+/CD16+) and monocytes (CD14+) show the highest secretion rates. IL-1 beta, IL-4, IL-6, IL-10, TNF alpha, and GM-CSF stimulate, whereas IL-2 and INF gamma inhibit, the hCG secretion of mononuclear cells. Flow cytometric experiments with hCG antibody demonstrate a binding of hCG on the surface of monocytes more than lymphocytes. The binding capacity is improved during pregnancy. Different hCG bands are shown in the Western blot analysis. We could confirm the mRNA of beta hCG and alpha CG are in MNC as well in the placental control. Peripheral MNC, first and foremost NK cells and monocytes, produce and secrete hCG during pregnancy, which play an important role for the corpus luteum rescue during the early gestational age and possibly for the immunotolerance.

Deficient processing and activity of type I insulin-like growth factor receptor in the furin-deficient LoVo-C5 cells

To investigate endoproteolytic processing of the type I insulin-like growth factor receptor (IGF-IR), we have examined its structure and activity in the furin-deficient LoVo-C5 cell line. Immunoprecipitation experiments using the monoclonal anti-IGF-IR antibody (alpha-IR3) showed that LoVo-C5 cells expressed a major high molecular mass receptor (200 kDa) corresponding to the unprocessed alpha/beta pro-receptor. A small amount of successfully cleaved alpha/beta heterodimers was also produced, indicating a residual endoproteolytic cleavage activity in these cells. In vitro, a soluble form of recombinant furin was able to cleave the pro-IGF-IR (200 kDa) into alpha-subunit (130 kDa) and beta-subunit (97 kDa). Measurement of IGF binding parameters in LoVo-C5 cells indicated a low number of typical type I IGF-binding sites (binding capacity, 5 x 10(3) sites/cell; Kd, 1.9 nM for IGF-I and 7.0 nM for IGF-II). These findings in LoVo-C5 contrast with those in HT29-D4 cells, which have active furin, and where IGF-IR (2.8 x 10(4) sites/cell) was fully processed. Moreover, the 200-kDa pro-IGF-IR of LoVo-C5 was unable to induce intracellular signaling, such as beta-subunit tyrosine autophosphorylation and insulin-related substrate-1 tyrosine phosphorylation. Flow immunocytometry analysis using alpha-IR3 antibody indicated that LoVo-C5 cells expressed 40% more receptors than HT29-D4 cells, suggesting that in LoVo-C5 cells only the small amount of mature type I IGF-IR binds IGFs with high affinity. To provide evidence for this idea, we showed that mild trypsin treatment of living LoVo-C5 cells partially restored alpha/beta cleavage of IGF-IR, and greatly enhanced (6-fold) the IGF-I binding capacity of LoVo-C5 cells, but did not restore IGF-IR signaling activity. Moreover, LoVo-C5 cells were totally unresponsive to IGF-I in terms of cell migration, in contrast to fully processed IGF-IR-HT29-D4 cells. Our data indicate that furin is involved in the endoproteolytic processing of the IGF-IR and suggest that this posttranslational event might be crucial for its ligand binding and signaling activities. However, our data do not exclude that other proprotein convertases could participate to IGF-IR maturation.

Beta interferon is produced by Chlamydia trachomatis-infected fibroblast-like synoviocytes and inhibits gamma interferon-induced HLA-DR expression

Infection of fibroblast-like synovial cells with Chlamydia trachomatis (serotype D strain IC Cal 8) in culture induced the secretion of beta interferon (IFN-beta). Chlamydial infection inhibited IFN-gamma-induced expression of HLA-DR antigen in the cells. Addition of IFN-beta antibody directly to infected cultures mitigated HLA-DR inhibition, suggesting involvement of produced IFN-beta.

Repression of hybrid dysgenesis in Drosophila melanogaster by combinations of telomeric P-element reporters and naturally occurring P elements

In Drosophila melanogaster, hybrid dysgenesis occurs in the germline of flies produced by crosses between females lacking P elements and males carrying 25-55 P elements. We have previously shown that a complete maternally inherited repression of P transposition in the germline (P cytotype) can be elicited by only two autonomous P elements located at the X chromosome telomere (cytological site 1A). We have tested whether P transgenes at 1A, unable to code for a P-repressor, may contribute to the repression of P elements. Females carrying a P-lacZ transgene at 1A ["P-lacZ(1A)"], crossed with P males, do not repress dysgenic sterility in their progeny. However, these P-lacZ(1A) insertions, maternally or paternally inherited, contribute to P-element repression when they are combined with other regulatory P elements. This combination effect is not seen when the P-lacZ transgene is located in pericentromeric heterochromatin or in euchromatin; however a P-w,ry transgene located at the 3R chromosome telomere exhibits the combination effect. The combination effect with the P-lacZ(1A) transgene is impaired by a mutant Su(var)205 allele known to impair the repression ability of the autonomous P elements at 1A. We hypothesized that the combination effect is due to modification of the chromatin structure or nuclear location of genomic P elements.

Catecholamines, heart rate, and oxygen uptake during exercise in persons with spinal cord injury

The purpose of this study was to investigate the influence of different injury levels in persons with spinal cord injury (SCI) on epinephrine (Epi) and norepinephrine (NE) at rest and during graded wheelchair exercise and the related changes in heart rate and O2 uptake (VO2). Twenty tetraplegics (Tetra), 10 high-lesion paraplegics (HLPara), 20 paraplegics with SCI below T5 (MLPara), and 18 able-bodied, nonhandicapped persons (AB) were examined. Because of the higher level of interruption of the sympathetic pathways, Tetra persons showed lower Epi and NE at rest and only slight increases during exercise compared with all other groups; the Tetra subjects' impaired cardiac sympathetic innervation caused restricted cardioacceleration and strongly reduced maximal VO2. When compared with AB persons, HLPara had comparable NE but lower Epi levels as a result of partial innervation of the noradrenergic system and denervation of the adrenal medulla. MLPara subjects showed an augmented basal and exercise-induced upper spinal thoracic sympathetic activity compared with AB subjects. The increase in heart rate in relation to VO2 was higher in HLPara because of a smaller stroke volume as a result of venous blood pooling. The different exercise response in persons with SCI is a result of the interruption of pathways in the spinal cord to the peripheral sympathetic nervous system in addition to the motor paralysis.

Effect of "living high-training low" on the cardiac functions at sea level

Living high-training low (LHTL), living at high altitude and training at sea level, is reported to be beneficial in enhancing physical performance. Effect of LHTL on cardiac function which is one of major determinants in performance, however, was not examined. To address this issue, 21 well-trained triathletes divided into control (n = 10, living and training at sea level) and LHTL group (living at 1980 m altitude > or = 12 hrs/day and training at sea level) were Doppler echocardiographically examined before and at the end of the two-week program. Heart rate and blood pressure did not change in both groups. At end of the training, left ventricular endsystolic diameter of LHTL group was smaller than that of controls (32 vs 34 mm, P < 0.05). Shortening fraction and ejection fraction in LHTL group increased by 9% and 17 %, respectively, P < 0.05. Preejection period/ejection time was more greatly reduced in LHTL group (P < 0.05). Stroke volume and cardiac output in LHTL increased. Diastolic function was not significantly affected by LHTL. These results suggest that LHTL produced an improvement of systolic function underlined by incremented left ventricular contractility, which might be associated with increased beta-adrenergic receptor or an improved myocardial energy utilization.

Training of rowers before world championships

In rowing, static and dynamic work of approximately 70% of the body's muscle mass is involved for 5.5 to 8 min at an average power of 450 to 550 W. In high load training phases before World Championships, training volume reaches 190 min.d-1, of which between 55 and 65% is performed as rowing, and the rest is nonspecific training like gymnastics and stretching and semispecific training like power training. Rowing training is mainly performed as endurance training, rowing 120 to 150 km or 12 h.wk-1. Rowing at higher intensities is performed between 4 and 10% of the total rowed time. The increase in training volume during the last years of about 20% was mainly reached by increasing nonspecific and semispecific training. The critical borderline to long-term overtraining in adapted athletes seems to be 2 to 3 wk of intensified prolonged training of about 3 h.d-1. Sufficient regeneration is required to avoid overtraining syndrome. The training principles of cross training, alternating hard and easy training days, and rest days reduce the risk of an overtraining syndrome in rowers.

Autonomic imbalance hypothesis and overtraining syndrome

PURPOSE

The parasympathetic, Addison type, overtraining syndrome represents the dominant modern type of this syndrome. Beside additional mechanisms, an autonomic or neuroendocrine imbalance is hypothesized as underlying.

METHODS/RESULTS

Several findings support this thesis. During heavy endurance training or overreaching periods, the majority of findings give evidence of a reduced adrenal responsiveness to ACTH. This is compensated by an increased pituitary ACTH release. In an early stage of the overtraining syndrome, despite increased pituitary ACTH release, the decreased adrenal responsiveness is no longer compensated. The cortisol response decreases. In an advanced stage of overtraining syndrome, the pituitary ACTH release also decreases. In this stage, there is additionally evidence for decreased intrinsic sympathetic activity and sensitivity of target organs to catecholamines. This is indicated by decreased catecholamine excretion during night rest, decreased beta-adrenoreceptor density, decreased beta-adrenoreceptor-mediated responses, and increased resting plasma norepinephrine levels and responses to exercise. However, this complete pattern is only observed subsequent to high-volume endurance overtraining at high caloric demands.

CONCLUSION

The described functional alterations of pituitary-adrenal axis and sympathetic system can explain persistent performance incompetence in affected athletes.

[Biological perspectives]

The tumour biology of non-small cell bronchial cancer integrates recent developments and a dynamic schema of the phenomena of tumour progression and diffusion of the metastatic disease. There is no leap of known biological disruption between Stage II and Stage III. The latter is defined by anatomical criteria and is a transition in the continuum of the natural history of these cancers. The moto for the tumour progression is the genotypic instability and phenotypic diversification. Metastatic microscopic disease constitutes the first cause of failure in the treatment of Stage III non-small cell bronchial cancer. Among prognostic factors for survival emphasis is placed on the alterations of p53 expression, different types of aneuploidy, anomalies of the expression of cellular adhesion molecules and finally, tumour diversification towards a metastatic phenotype.

[Standards, Options, and Recommendations for the management of patients with malignant mesothelioma of the pleura. Fédération Nationale des Centres de Lutte Contre le Cancer]

The "Standards, Options and Recommandations" (SOR), started in 1993, are a collaborative project between the Federation of the French Cancer Centres (FNCLCC), the 20 French Cancer Centres and specialists from French Public Universities, General Hospitals and Private Clinics. The main objective is the development of clinical practice guidelines to improve the quality of health care and outcomes for cancer patients. The methodology is based on literature review and critical appraisal by a multidisciplinary experts group, with feedback from specialists in cancer care delivery. The objectives are to develop a clinical practice guideline with definitions of Standards. Options and Recommendations for the clinical care of malignant pleural mesothelioma. Data have been identified by literature search using Medline (1966-June 1997) and personal references lists. The main criteria considered were incidence, risk factors, pronostic factors and efficacy of cancer treatment. Once the guideline was defined, the document was submitted to 40 independent reviewers for peer review, and to the medical committees of the 20 French Cancer Centres for review and agreement. The results are: 1) systematic assessment of (professional) exposure to asbestos is based on a standardized interrogatory, completed by specific consultation for professional disease; 2) diagnostic and clinical staging is based on multiple biopsies under thoracoscopy and thoracic scanner; 3) there is no indication for extemporaneous examination, immunocytochemistry should use cytokeratine, EMA, vimentine, ACE, Leu-M1; 4) clinical care: the recommended staging classification is the IMIG (International Mesothelioma Interest Group) classification; 5) validated, independent pronostic factors are stage of disease patient's functional status and histologic type (i.e. epithelial lesions are of better prognosis); 6) treatment is based on symptomatic and palliative treatment options. Anticancer treatments (surgery, chemotherapy, immunotherapy, radiotherapy) did not show significant improvement of survival. The inclusion of patients in clinical trials is recommended.

Effect of microtubule disruption on cell adhesion and spreading

Microtubules have been involved in a variety of cellular processes. In this study, we examined the role of the microtubular system in the adhesion and spreading of the adenocarcinoma cell line HT29-D4. Disruption of microtubules by nocodazole or navelbine resulted in an increase in cell adhesion to purified ECM proteins. This enhanced cell adhesion is mediated by integrins, but is not attributable to quantitative changes in the number of integrin receptors at the cell surface, as determined by flow cytometric analysis. In contrast to attachment, spreading of HT29-D4 cells was reduced by nocodazole treatment in a dose-dependent manner. Thus, microtubule depolymerization appears to increase initial attachment of cells to extracellular matrix, while impeding subsequent cell spreading.

Impaired cardiac uptake of meta-[123I]iodobenzylguanidine in Parkinson's disease with autonomic failure

OBJECTIVE

To selectively investigate postganglionic sympathetic cardiac neurons in patients with Parkinson's disease and autonomic failure.

MATERIAL AND METHODS

Metaiodobenzylguanidine (MIBG) is a pharmacologically inactive analogue of noradrenaline, which is similarly metabolized in noradrenergic neurons. Therefore the uptake of radiolabelled MIBG represents not only the localization of postganglionic sympathetic neurons but also their functional integrity. Ten patients with Parkinson's disease and autonomic failure underwent standardized autonomic testing, assessment of catecholamine plasma levels and scintigraphy with [123I]MIBG.

RESULTS

The cardiac uptake of MIBG, as demonstrated by the heart/mediastinum ratio, was significantly lower in patients in comparison with controls. Scintigraphy with MIBG allowed the selective in-vivo investigation of postganglionic sympathetic cardiac efferents in patients with autonomic failure, a procedure which was previously confined to post-mortem examination.

CONCLUSION

These findings point to a relevant postganglionic pattern of involvement of the autonomic nervous system (ANS) in Parkinson's disease and autonomic failure.

Effect of felodipine on regional blood supply and collateral vascular resistance in patients with peripheral arterial occlusive disease

This double-blinded, randomized, placebo-controlled study was designed to investigate the acute effect of felodipine on regional blood supply and collateral vascular resistance in patients with peripheral arterial occlusive disease (PAOD). Thirty men with PAOD were treated with a single dose of 5 mg felodipine or placebo. Systolic blood pressure (SBP), Doppler ankle pressure (DAP), calf blood flow (CBF) by venous occlusion plethysmography and calf transcutaneous oxygen tension (tcpO2) were measured during a cycle ergometry. Felodipine reduced SBP significantly (from 149 to 136 mmHg, p < 0.05), while placebo did not. DAP increased slightly but not significantly in both groups. The pressure gradient between SBP and DAP fell significantly in the felodipine group (60 vs 39 mmHg, p < 0.01) but not in the placebo group (59 vs 56 mmHg). There was a trend for lower velocity in tcpO2 decrease during the stress test and higher velocity of tcpO2 increase during recovery from exercise in the felodipine group although the differences between both groups were not significant. In the felodipine group, CBF increased by 35.6% (p < 0.05) whereas it did not change in the placebo group. In conclusion, while lowering SBP, felodipine increased slightly, or at least maintained, the blood supply to the calves in PAOD patients, which probably results from reducing collateral vascular resistance.

Ultra-triathlon-related blood-chemical and endocrinological responses in nine athletes

BACKGROUND

Objective of this study was to get more insight in hematology, biochemistry, and endocrinology of ultra-endurance exercise, to improve knowledge in this field, supplementation, and medical care of affected athletes.

METHODS

A large body of individual hematological, biochemical, and endocrinological parameters was analyzed in the blood taken from ultra-athletes before and after completing the 1993 Colmar ultra triathlon covering 7.5 km swimming, 360 km cycling, and approximately 85 km running.

PARTICIPANTS

Nine experienced ultra-athletes participated in the study. A follow-up was not possible since the athletes left Colmar within 24 hrs after the contest.

RESULTS

The athletes finished the ultra-contest at rankings 4, 5, 7, 8, 9, 11, 18, 22, 23 in a total time between 23:38:53 and 27:54:30 hr:min:sec. Their final body mass (68.6 +/- 1 kg) was significantly lower than at baseline (71.9 +/- 4.2 kg). Non of the athletes made use of medical care. Data after this contest reflect mild hyponatremia, intravascular hemolysis, increased triglyceride turnover, acute-phase reaction, hyperaldosteronemia 2061 +/- 1013 pmol.L-1), hypercortisolemia 971 +/- 486 nmol.L-1), hyper-growth-hormonemia (median 6.8 ng.ml-1), hypoinsulinemia, hypo-free-testosteronemia (42 +/- 17 pmol.L-1), protein catabolism, depressed testicular function, oliguria, and muscle cell leakage.

CONCLUSIONS

In our opinion, data presented do not reflect any acute health risks in healthy athletes who are well prepared and carefully supplied during such a contest.

Lung diffusing capacity and exercise in subjects with previous high altitude pulmonary oedema

Subjects with a history of high-altitude pulmonary oedema (HAPE) have increased pulmonary artery pressure and more ventilation-perfusion (V'A/Q') inhomogeneity with hypoxia and exercise. We used noninvasive methods to determine whether there are differences in the pulmonary diffusing capacity for carbon monoxide (DL,CO) and cardiac output (Q') during exercise, indicative of a more restricted pulmonary vascular bed in subjects with a history of HAPE. Eight subjects with radiographically documented HAPE and five controls with good altitude tolerance had standard pulmonary function testing and were studied during exercise at 30 and 50% of normoxic maximal oxygen consumption (V'O2) at an inspiratory oxygen fraction of 0.14 and 0.21. DL,CO and Q' were measured by CO and acetylene rebreathing techniques. HAPE-resistant subjects had 35% greater functional residual capacity than HAPE-susceptible subjects. Vital capacity and total lung capacity were also 7-10% greater. There were no differences in airflow rates or resting diffusing capacity. However, DL,CO in HAPE-susceptible subjects was lower in hypoxia and with exercise, and showed less increase (32 versus 49%) with the combined stimulus of hypoxic exercise. HAPE-susceptible subjects had smaller increases in stroke volume, Q', and ventilation during exercise. The findings are consistent with lower pulmonary vasoconstriction, greater vascular capacitance and greater ventilatory responsiveness during exercise in subjects who are resistant to high-altitude pulmonary oedema. Their larger lung volumes suggest a constitutional difference in pulmonary parenchyma or vasculature, which may be a determinant of high-altitude pulmonary oedema resistance.

Lung diffusing capacity and exercise in subjects with previous high altitude pulmonary oedema

Subjects with a history of high-altitude pulmonary oedema (HAPE) have increased pulmonary artery pressure and more ventilation-perfusion (V'A/Q') inhomogeneity with hypoxia and exercise. We used noninvasive methods to determine whether there are differences in the pulmonary diffusing capacity for carbon monoxide (DL,CO) and cardiac output (Q') during exercise, indicative of a more restricted pulmonary vascular bed in subjects with a history of HAPE. Eight subjects with radiographically documented HAPE and five controls with good altitude tolerance had standard pulmonary function testing and were studied during exercise at 30 and 50% of normoxic maximal oxygen consumption (V'O2) at an inspiratory oxygen fraction of 0.14 and 0.21. DL,CO and Q' were measured by CO and acetylene rebreathing techniques. HAPE-resistant subjects had 35% greater functional residual capacity than HAPE-susceptible subjects. Vital capacity and total lung capacity were also 7-10% greater. There were no differences in airflow rates or resting diffusing capacity. However, DL,CO in HAPE-susceptible subjects was lower in hypoxia and with exercise, and showed less increase (32 versus 49%) with the combined stimulus of hypoxic exercise. HAPE-susceptible subjects had smaller increases in stroke volume, Q', and ventilation during exercise. The findings are consistent with lower pulmonary vasoconstriction, greater vascular capacitance and greater ventilatory responsiveness during exercise in subjects who are resistant to high-altitude pulmonary oedema. Their larger lung volumes suggest a constitutional difference in pulmonary parenchyma or vasculature, which may be a determinant of high-altitude pulmonary oedema resistance.

The presence of chorionic gonadotrophin beta subunit in normal cyclic human endometrium

The aim of the present study was to determine whether human endometrial cells are able to secrete beta-chorionic gonadotrophin (betaCG). Immunohistochemical studies and in-situ hybridization were performed in order to provide evidence for the occurrence of betaCG in the normal endometrium in 15 patients in the proliferative phase, two patients in the periovulatory phase and 13 patients in the secretory phase. Neither immunohistochemical nor hybridization reactions could be recognized during the proliferative phase. In contrast, both protein and betaCG mRNA were observed in the glandular cells of the endometrium during the secretory phase. The results were supported by Western blotting of secretory phase endometrium extracts and the assessment of the functional secretory capacity of primary endometrium cultures. In comparison with cultured and separated cell fractions, tissue extracts showed a higher betaCG, indicating a regulatory interaction. In conclusion, betaCG can be demonstrated in normal human cyclic endometrium, suggesting a paracrine role in endometrial physiology.