Prolactin-screening tumors and hypogonadism in 22 men.

We studied 22 men with prolactin-secreting pituitary tumors and hypogonadism. Twenty complained of impotence, nine had visual impairment, and three experienced galactorrhea. None of the 17 patients undergoing operation or radiotherapy, or both, were subsequently normoprolactinemic. In all 13 patients treated with bromocryptine major clinical improvement was associated with a decrease in serum prolactin levels and in nine with an increase in serum testosterone. Two patients receiving testosterone replacement therapy showed improved potency only after bromocryptine was administered. The results indicate that hyperprolactinemia frequently induces hypogonadism in men, that bromocryptine ameliorates symptoms of disease previously unchanged by operation or radiotherapy, and that the impotence observed may not be solely the result of hypogonadism.     

Egfl7 knockdown causes defects in the extension and junctional arrangements of endothelial cells during zebrafish vasculogenesis.

The endothelial cell (EC) -specific secreted protein EGFL7 is important for tubulogenesis in newly forming blood vessels. We studied its role in vascular tube formation by a quantitative ultrastructural analysis of Egfl7-knockdown zebrafish embryos. At 24 hours postfertilization, the endothelia of dorsal aorta (DA) and posterior cardinal vein (PCV) were correctly anchored to the hypochord and endoderm, respectively, but failed to expand into the vascular area. This resulted in vessels with reduced or split lumen and open sheets of ECs. Concomitantly, the organization of hematopoietic cells-identified by the presence of previously undescribed membrane tubules-between DA and PCV, and within the vessels, was severely disturbed. Strikingly, ectopic cell junctions occurred across the obstructed vessel lumen, on the luminal EC surfaces, which in control conditions never display junctions of any kind. These data suggest that Egfl7 provides ECs with a cue for their extension into the vascular area and in establishing EC cell polarity.     

Social support and the persistence of complaints in chronic fatigue syndrome

BACKGROUND: Several studies suggested that the surroundings of chronic fatigue syndrome (CFS) patients are of importance in the persistence of complaints. Contrary to what was expected, participation in support groups has not led to clinical improvement. The purpose of the present study was to describe social support in CFS patients as compared with other fatigued and non-fatigued groups. Further, changes in social support and the influence of social support on the course of CFS over a period of more than 1 year were studied in patients with and without treatment. METHODS: Baseline data were assessed in 270 CFS patients, 150 disease-free breast cancer patients, 151 fatigued employees on sick-leave and 108 healthy subjects using the Social Support List and Significant Others Scale. CFS patients were followed in cognitive behaviour therapy (CBT), guided support groups and natural course at 8 and 14 months. RESULTS: CFS patients and fatigued employees reported more negative interactions and insufficiency of supporting interactions than cancer patients and healthy controls. No differences in frequency of supporting interactions were found. Negative interactions decreased significantly after treatment with CBT, but did not change in support groups or natural course. In the natural course, higher fatigue severity at 8 months was predicted by more negative interactions at baseline. CONCLUSIONS: In CFS patients and fatigued employees, social support is worse than in disease-free cancer patients and healthy controls. Lack of social support was identified as a new factor in the model of perpetuating factors of fatigue severity and functional impairment in CFS.     

Irritant symptoms and immunologic responses to multiple chemicals: importance of clinical and immunologic correlations

An evaluation of workers in a plant was conducted because of multiple complaints of ocular, nasal, skin and chest symptoms. Antibody activity against 4 different chemicals was identified: an aliphatic diisocyanate, 4-vinylcyclohexene dioxide, trimellitic anhydride (TMA) and an unknown chemical present in a plasticizing ester known as n-octyl-n-decyl-trimellitate. The source of TMA which resulted in immunization in the plant is unknown. The presence or absence of antibodies did not correlate with the presence or absence of symptoms and it was concluded that no occupational allergic disease was present in these workers. Antibody studies alone do not make a diagnosis of occupational allergic disease and clinical correlation is required. Immunoassays may be useful in identifying exposures to immunizing chemicals in the workplace for potential clinical correlation or for exposure monitoring in the workplace.     

Physical characterization of PBCV virus by sedimentation field flow fractionation

A virus (PBCV) from the symbiotic Chlorella-like algae of Paramecium bursaria has been characterized by sedimentation field flow fractionation (SdFFF). The method yields effective molecular weight M' (molecular weight X buoyancy factor) with a precision of better than 5% under a variety of experimental conditions. The value for M' is used to calculate true molecular weight values through combination with density values; densities were obtained from outside sources, from ultrasonic densitometry, and from sedimentation coefficients determined independently. The actual molecular weight is also determined through SdFFF analysis of the virus in carriers of different densities. Values for the particle diameter are obtained from SdFFF zone broadening studies. The various SdFFF characterization results are compared with molecular weight, particle size, and density values determined by conventional methods.     

3q−, 3q+ anomaly in malignant proliferations in humans

Anomalies of both No. 3 chromosomes, of the t(3q?; 3q+) type can be observed in human malignancy as reported previously. It is our experience that this anomaly is found predominantly in myeloproliferative disorders, as a rather rare event, though occurring more frequently than similar exchanges between other homologous chromosomes. Previous claims about a relationship between this anomaly and thrombocytosis could not be confirmed, but the features found in a few patients indicate that further research should be undertaken to clarify this point.     

A small-conductance charybdotoxin-sensitive,apamin-resistant Ca2+-activated K+ channel in aortic smooth muscle cells (A7r5 line and primary culture)

A small conductance K⁺ channel was identified in smooth muscle cells of the rat aortic cell line A7r5 and also in rat aortic smooth muscle cells in primary culture, using conventional single-channel recording techniques. The single-channel conductance shows no rectification, either in the range –70 to +40 mV under asymmetrical conditions (9.1 pS), or in the range –100 to +50 mV in symmetrical 150 mM K⁺ (37 pS). Channel activity is reversibly inhibited by extracellular application of charybdotoxin, with a concentration of 8 nM producing half-maximal inhibition. It is unaffected by apamin or scyllatoxin. Channel activity depends on the presence of free Ca²⁺ on the cytosolic face of the membrane, with an activation zone between 0.1 and 1 M. This small-conductance, charybdotoxin-sensitive, Ca²⁺-regulated K⁺ channel is activated by vasoconstrictors such as vasopressin and endothelin.     

Detection of hypodense eosinophils by Percoll multilayer density gradient centrifugation in subjects with normal or slightly elevated eosinophilia. Poor reproducibility and eosinophils of density < 1.077 g/ml.

In patients with marked hypereosinophilia 'hypodense' and 'normodense' eosinophils have been found after density gradient centrifugation. Subsequently this terminology has also been used in studies of patients with milder eosinophilia. However, in these cases the differentiation between normo- and hypodense eosinophils was less clear. This might be due to the high imprecision of the test of density gradient centrifugation, as demonstrated in the first part of this study: the mean within-assay variance of the number of eosinophils in the different density layers was 35%. It was calculated that the test must be performed eight times to obtain an estimate of the true mean for the individual patient. In the second part of the study, the absolute number of 'hypodense eosinophils' in groups of patients with asthma (adults and children) and rheumatoid arthritis (adults) were compared to normal controls. Although a difference in the absolute number of hypodense eosinophils between groups of patients and controls could be demonstrated, the high imprecision of the test of density gradient centrifugation suggested that the technique used was not useful in an individual with normal or slightly elevated eosinophils in the peripheral blood.