Bacterial endocarditis. II. A prospective study with clinical, laboratory and therapeutic observations

Genome-wide DNA methylome analysis identifies methylation signatures associated with survival and drug resistance of ovarian cancers

BACKGROUND

In contrast to stable genetic events, epigenetic changes are highly plastic and play crucial roles in tumor evolution and development. Epithelial ovarian cancer (EOC) is a highly heterogeneous disease that is generally associated with poor prognosis and treatment failure. Profiling epigenome-wide DNA methylation status is therefore essential to better characterize the impact of epigenetic alterations on the heterogeneity of EOC.

METHODS

An epigenome-wide association study was conducted to evaluate global DNA methylation in a retrospective cohort of 80 mixed subtypes of primary ovarian cancers and 30 patients with high-grade serous ovarian carcinoma (HGSOC). Three demethylating agents, azacytidine, decitabine, and thioguanine, were tested their anti-cancer and anti-chemoresistant effects on HGSOC cells.

RESULTS

Global DNA hypermethylation was significantly associated with high-grade tumors, platinum resistance, and poor prognosis. We determined that 9313 differentially methylated probes (DMPs) were enriched in their relative gene regions of 4938 genes involved in small GTPases and were significantly correlated with the PI3K-AKT, MAPK, RAS, and WNT oncogenic pathways. On the other hand, global DNA hypermethylation was preferentially associated with recurrent HGSOC. A total of 2969 DMPs corresponding to 1471 genes were involved in olfactory transduction, and calcium and cAMP signaling. Co-treatment with demethylating agents showed significant growth retardation in ovarian cancer cells through differential inductions, such as cell apoptosis by azacytidine or G2/M cell cycle arrest by decitabine and thioguanine. Notably, azacytidine and decitabine, though not thioguanine, synergistically enhanced cisplatin-mediated cytotoxicity in HGSOC cells.

CONCLUSIONS

This study demonstrates the significant association of global hypermethylation with poor prognosis and drug resistance in high-grade EOC and highlights the potential of demethylating agents in cancer treatment.

Septicemia and endocarditis caused by group G streptococci in a Norwegian hospital

The clinical and bacteriological features of septicemia caused by group G streptococci were analyzed in nine patients seen during a period of 28 months. Four of these patients had acute endocarditis with a high rate of serious neurological complications. The clinical response to antibiotic treatment was slow in the endocarditis patients despite sensitivity of the organism in vitro. Group G streptococcal septicemia can be a very serious condition associated with endocarditis of a destructive nature. Comparison with previous reports suggests that group G streptococcal infections are of increasing importance. The virulence of group G streptococci may be changing, resulting in more serious infections and complications. This series stresses the importance of prompt recognition of this infection and the need for aggressive management of these patients.

Infective endocarditis 1973-1984 at the Bergen University Hospital: clinical feature, treatment and prognosis

During the period 1973-1984, 72 patients with infective endocarditis (IE) were hospitalized in the medical department, Bergen University Hospital. The male/female ratio was 1.25/1, the mean age 55.3 years. 35 infections were caused by streptococci, 18 by staphylococci, 6 by other microorganisms and in 13 cases no causal organism was found. Only 13 patients had rheumatic heart disease. The overall mortality was 35%, and the mean age of the patients who died was 65 years. The case fatality rates for staphylococcal and streptococcal endocarditis were 61 and 24% respectively. In the period 1973-1978 the case fatality rate was 50% compared to 26% during 1979-1984. The proportion of patients with culture-negative endocarditis was reduced from 31 to 11% from the first to the second half of the study and the percentage of patients who received antibiotics before diagnosis decreased from 81 to 58%. Valve replacement was performed in 4 patients with staphylococcal and 15 with streptococcal infections. Seven cases (mean age 73.4 years) were diagnosed at necropsy; 3 with staphylococcal infections. With increased clinical awareness of IE, liberal use of blood cultures, better diagnostic tools and earlier surgical intervention, especially in staphylococcal infections, a further reduction in mortality should be possible.

A prospective study on septicemia. II. Clinical manifestations and complications, results of antimicrobial treatment and report of a follow-up study

In a prospective study at a hospital for infectious diseases 151 patients, 110 with proved and 41 with probable septicemia, were analysed. Clinical, laboratory, therapeutic data and prognostic experiences, partly from a follow-up study, are described. Secondary manifestations, mostly from skin, mucous membranes, nervous system and lungs, were present in 72%. They were more often caused by gram-positive cocci than by gram-negative baccilli and in some cases not revealed until autopsy. Lesions in the nervous system were most often caused by strepto- or penumococci or Haemophilus influenzae. In 2 splenectomized patients with extensive hemorrhages, pneumococci were isolated. Subacute courses were rare even in alpha-streptococcal infection and its "classical signs" were never observed. Shock and thrombocytopenia suggesting disseminated intravascular coagulation occurred together in 11%, and in one-third in the lethal cases. Gram-positive bacteria were often involved. Leukocytosis was absent in 53 patients; 20 were alcohol or narcotic drug abusers, and 7 died. ECG changes were registered in 33%. Initial antibiotic treatment was applied according to a fixed schedule, with cure in 61% on this first treatment, and especially so in infections with gram-positive cocci. During the initial hospital stay 20% died from uncontrolled infection. All had underlying diseases or factors, often major causes of death. The infection was regarded as hospital-acquired in 40% among the lethal cases. During a one-year follow-up period 3 patients died from a new septicemia and 10 from their underlying disease.

Septicemia I. A prospective study on etiology, underlying factors and sources of infection

In a prospective study, 110 cases of proved and 41 of probable septicemia were analysed. Underlying diseases or factors were common, also in young patients, often narcotic drug or alcohol abusers. In one third, septicemia was probably hospital-acquired. Streptococci, staphylococci and gram-negative enteric rods were most common, followed by pneumococci and haemophilus species. Staphylococci and gram-negative enteric rods dominated in patients hospitalized at or before the onset of disease, and staphylococci in patients with vascular foreign bodies and in drug addicts. Enteric rods were common in elderly patients with urogenital disease, especially after instrumentation. Among streptococci, alpha-streptococci dominated; they did not emanate as often from dental foci as expected. In 2 of 3 asplenic patients with extensive hemorrhages pneumococci were found. Bacteria of low virulence and fungi occurring as opportunists were rare. Mixed infections, present in 4 cases, were severe. Portals of entry could often be proved or assumed. In half of all patients, the same organism was isolated from a primary focus as from blood. The importance of underlying illnesses and factors and of invasive procedures was evident. A tentative etiological diagnosis could often be made, based on case history, underlying factors and the probable portal of entry.