Significance of the number of embryonic cells and the state of the zona pellucida for hatching of mouse blastocysts in vitro versus in vivo.

We investigated the course of mouse blastocyst hatching in vitro after experimental modulation of the hatching process by growth hormone or by laser treatment and compared it to embryos grown in vivo. When embryos were grown in vitro, successful hatching was dependent on blastocyst expansion and was based on a minimum number of embryonic cells. Embryos grown in the presence of growth hormone were more advanced in their development and hatched earlier. When an artificial opening was laser-drilled into the zona pellucida, hatching occurred at lower numbers of embryonic cells. In vivo, escape from the zona pellucida occurred earlier and independent of blastocyst expansion. However, when we isolated in vivo-grown blastocysts with intact zonae that had developed in vivo and then cultured them in vitro, blastocysts started to expand and hatched the following day when a sufficiently high number of embryonic cells was present. Our data show that successful hatching in vitro is dependent on a sufficiently high number of embryonic cells, which enables blastocyst expansion and zona shedding. In vivo, the lower number of embryonic cells detected in zona-free blastocysts indicates that the underlying mechanism of zona escape is different, does not depend on blastocyst expansion, and presumably involves lytic factors from the uterus.

Hormonal, syndromal and EEG mapping studies in menopausal syndrome patients with and without depression as compared with controls.

UNLABELLED: The aim of the study was to investigate brain function in menopausal depression by EEG mapping, as compared with menopausal syndrome patients without depression and normal controls, and to correlate neurophysiological with clinical and hormonal findings in order to elucidate the pathogenesis of depression in the menopause. METHODS: One hundred and twenty-nine menopausal women, aged 45-60 years, with no previous hormonal replacement therapy were investigated in regard to hormones (estradiol [E2], follicle stimulating hormone [FSH]), clinical symptomatology (Kupperman Index [KI], Hamilton depression score [HAMD]) and brain function (EEG mapping). Based on KI and DSM-III-R research criteria for major depression, 3 groups were available for statistics (after removal of protocol violators): group A had a KI of <15 and no depression (n = 29); group B had a KI of > or = 15 and no depression (n = 29) and group C had a KI of > or = 15 and fulfilled the criteria for major depression (n = 60). RESULTS: EEG maps of depressed patients demonstrated less total power and absolute power in the delta, theta and beta band, more relative delta and less alpha power as well as a slower delta/theta and faster alpha and beta centroid than controls, suggesting a vigilance decrement. Group B did not differ from group A. Correlation maps showed significant relationships between estradiol levels and EEG measures (the lower the E2, the worse the vigilance) and between the EEG measures and the Hamilton depression (HAMD) score (the worse the vigilance, the higher the depression score). There were no correlations between the hormones E2 and FSH and the syndromes KI and HAMD. In the target variable, the asymmetry index, depressed patients showed less alpha power over the right than left frontal lobe, whereas normal controls exhibited the opposite. Group B did not differ from group A. The frontal asymmetry index was significantly correlated with the Hamilton depression score and suggests right frontal hyper- and left frontal hypoactivation in depression. CONCLUSIONS: Although hormonal findings are not directly linked to psychic changes, low estradiol levels do contribute to a decreased vigilance at the neurophysiological level , which is in turn correlated with higher depressive and menopausal symptomatology at the behavioural level. Depression is further correlated to a right frontal hyper- and left frontal hypoactivation.

Excretion of Ascaris lumbricoides during total body irradiation.

We describe the excretion of Ascaris lumbicoides, an intestinal roundworm, in the emesis of an asymptomatic patient undergoing total body irradiation. This suggests that Ascaris is sensitive to irradiation.

The changing epidemiology of infections at cancer hospitals.

Intensive chemotherapy regimens, widespread prophylactic and therapeutic administration of antibiotics, reliance on intravascular catheters, increased use of immunomodulators, and increased outpatient management have altered the epidemiology of infections in patients with neoplastic disease. At many centers, bacteremias due to gram-positive organisms have replaced bacteremias due to gram-negative organisms as the most frequent infections in patients with cancer. Isolation of gram-negative bacilli other than Enterobacteriaceae and Pseudomonas aeruginosa has increased in frequency, and these organisms have become important pathogens. Fungal infections have become a leading cause of morbidity and mortality, and nosocomial fungemias have become more common than nosocomial bacteremias due to gram-negative bacilli in some centers. Mycobacterium tuberculosis, Pneumocystis carinii, and rubeola virus have reemerged as disease-causing entities in patients with cancer. Multiresistant organisms have developed over the past decade. Anticipated trends in infections in patients with cancer also are discussed.

Changing patterns of infections in the immunocompromised patient with cancer.

Infectious complications have become frequent causes of morbidity and mortality in cancer patients, often replacing the primary disease as the leading cause of death. Intensive chemotherapy regimens, widespread prophylactic and therapeutic administration of antibiotics, and reliance on intravascular catheters have altered the epidemiology of infections in these patients. The authors review how gram-positive bacteremias have replaced gram-negative bacteremias as the leading causes of infections in many patients with cancer, and how fungal infections have become a leading cause of morbidity and mortality as bacterial infections are better controlled. Multiresistant organisms that have developed during the past decade and future trends in infectious complications of cancer patients are also discussed.

Disseminated Nocardia brasiliensis infection with septic arthritis.

An unusual case of disseminated Nocardia brasiliensis infection is presented. The patient, who had been receiving chronic dexamethasone therapy for 4 years, had pneumonia and septic arthritis of the left knee due to N. brasiliensis. To our knowledge, this is the first report from the United States of a synovial joint infection with this organism. Disseminated disease due to N. brasiliensis is infrequently reported; it is most often seen in the immunocompromised patient and is often unresponsive to therapy.

Effects of exogenous polyamine and trypanocides on the DNA polymerase activities from Trypanosoma brucei brucei, mouse thymus and murine leukemia virus.

The effects of exogenously added spermine on activated (gapped) DNA-directed and poly(dC) . (dG)12-18-directed DNA synthesis were tested on the chromatographically separated DNA polymerase activities of Trypanosoma brucei brucei. Activated DNA-directed DNA synthesis by the Peak I (eluting from DNA-agarose at 0.15 M KCl) and Peak II (eluting at 0.3 M KCl) polymerase was consistently inhibited or stimulated, respectively, by exogenous spermine. Kinetic analysis revealed that inhibition of the Peak I enzyme with respect to template DNA occurred by a mixed mechanism, while a major factor in the stimulation of the Peak II enzyme by spermine appeared to be the polyamine-mediated reversal of "substrate inhibition' by DNA at concentrations above 10 micrograms/ml. The apparent Km values of Peak I and Peak II DNA polymerase for activated DNA were determined to be 5 and 0.5 microgram/ml, respectively. In contrast to the results observed with activated DNA, activation of Peak II-enzyme-catalyzed poly(dC)-directed DNA synthesis was similar at all template-primer concentrations. Peak I enzyme-catalyzed poly(dG) synthesis was either inhibited or slightly stimulated by spermine, depending upon the presence or absence of heteropolymeric DNA, respectively. Dose-dependent inhibition of DNA-directed DNA synthesis catalyzed by T. b. brucei DNA polymerases, murine thymus DNA polymerase alpha, and Rauscher murine leukemia virus reverse transcriptase by trypanocides was examined to determine a possible mechanism of selective toxicity by such agents. The drugs Antrycide (quinapyramine), pentamidine, imidocarb, Berenil (diminazene aceturate), WR-199-385-[2,5-bis(4-guanylphenyl)furan . 2HCl] and isometamidium inhibited DNA polymerases of the eucaryotic cells at approximately the same degree, and at similar concentrations. The presence of spermine in reaction mixtures did not spare any drug inhibition. Stimulation of reverse transcriptase activity was observed in the presence of Antrycide and imidocarb, however, this could be negated by stimulatory amounts of spermine present in the reaction mixture. The results, obtained using an activated DNA-directed assay system, suggest that trypanosomal DNA polymerases are not the selective target of trypanocidal drugs currently available.