A potential role of fetal hemoglobin in the development of multidrug resistance.

Our previous data from a human leukemic cell line made resistant to the nucleoside analog (NA) 9-ß-D-arabinofuranosylguanine (AraG) revealed a massive upregulation of fetal hemoglobin (HbF) genes and the ABCB1 gene coding for the multidrug resistance P-glycoprotein (P-gp). The expression of these genes is regulated through the same mechanisms, with activation of the p38-MAPK pathway and inhibition of methylation making transcription factors more accessible to activate these genes. We could show that AraG, as well as other NAs, and P-gp substrates could induce global DNA demethylation and induction of Hbγ and P-gp both at the mRNA and protein expression level. We speculate that the expression of HbF prior to drug exposure or in drug-resistant cell lines is a strategy of the cancer to gain more oxygen, and thereby survival benefits. We also believe that P-gp may be induced in order to excrete Hb degradation products from the cells that would otherwise be toxic. By using Hbγ siRNA and pharmacological inhibitors of HbF production we here present a possible relationship between HbF induction and multi-drug resistance in a human leukemia cell line model.

Fetal haemopoiesis marking low-grade urinary bladder cancer.

BACKGROUND: The immunohistochemical features of fetal haemoglobin cells and their distribution patterns in solid tumours, such as colorectal cancer and blastomas, suggest that fetal haemopoiesis may take place in these tumour tissues. These locally highly concentrated fetal haemoglobin (HbF) cells may promote tumour growth by providing a more efficient oxygen supply. METHODS AND RESULTS: Biomarkers of HbF were checked in transitional cell carcinoma (TCC) of the urinary bladder, assessing this as a new parameter for disease management. Fetal haemoglobin was immunohistochemically examined in tumours from 60 patients with TCC of the bladder. Fetal haemoglobin erythrocytes and erythroblasts were mainly clonally distributed in proliferating blood vessels and not mixed with normal haemoglobin erythrocytes. The proportion of such HbF blood vessels could reach more than half of the total number of vessels. There were often many HbF erythroblasts distributed in one-cell or two-cell capillaries and present as 5-15% of cells in multi-cell vessels. This suggests a local proliferation of HbF-cell progenitors. Fetal haemoglobin cells were prominently marking lower grades of tumours, as 76% (n=21) of the patients with G1pTa were HbF+, whereas only 6.7% (n=30) of the patients with G3pT1-pT2a were HbF+. CONCLUSION: Our results suggest that HbF, besides being a potential new marker for early tumour detection, might be an essential factor of early tumour development, as in fetal life. Inhibiting HbF upregulation may provide a therapeutic target for the inhibition of tumour growth.

Titrimetric immunohistochemical evaluation of DNA hypomethylation in uterine tumours.

BACKGROUND: Global DNA hypomethylation is a well established feature of many common cancers. AIMS: To establish a simple semi-quantitative, titrimetric immunohistochemical method in order to exploit this trait for prognostic purposes, in uterine cancers. METHODS: A monoclonal antibody against 5-methylcytidine was used for immunohistochemical staining of methylated DNA in tumour cells. The degree of methylated DNA in the tumour tissue was visually compared and matched to that of normal tissues stained by serial decreasing concentrations of antibody to 5-methylcytidine. RESULTS: Using this method a significant correlation was found between the histological stage and the reduction in DNA methylation in uterine adenocarcinoma (n = 39) and uterine squamous cell carcinoma (n = 23). CONCLUSIONS: A simple titrimetric immunohistochemical method has been developed for quantitative evaluation of ligands. This method should be further employed in follow-up studies, in order to establish the prognostic value of DNA hypomethylation in uterine cancer.

Foetal haemoglobin-blood cells (F-cells) as a feature of embryonic tumours (blastomas).

Tumour markers are important in the diagnosis and monitoring of many tumours. This study tested the hypothesis that an oncofoetal protein, foetal haemoglobin (HbF) is a potential tumour marker in embryonic tumours, useful for management. An immunohistochemical investigation of HbF blood cell (Fc) distribution was carried out in tumours and in bone marrow samples from 83 children and 13 adults with various embryonic tumours (blastomas), and in bone marrow samples of 24 leukaemia patients. In the three, main blastoma types, nephroblastoma (Wilms' tumour), neuroblastoma and retinoblastoma, where all the patients, except two, were children, around 80% of the tumour samples had Fc within proliferating blood vessels and spaces between tumour cells. In parallel, clusters of Fc, mostly F-erythroblasts (Feb), were distributed in the bone marrow of some of those patients and in the bone marrow of 79% of the leukaemia patients. Foetal haemoglobin, as well as being a potential prognostic cancer marker, is a potential indicator of DNA hypomethylation implicated in the development of these tumours, as well as in others previously noted for the presence of HbF.

Development of fetal haemoglobin-blood cells (F cells) within colorectal tumour tissues.

AIM: To evaluate the sources of fetal haemoglobin (HbF) as an indicator in cancer. An immunohistochemical study was carried out on some of the most common kinds of cancer. All of these cancers had serologically high levels of HbF as evaluated previously. METHODS: Immunoaffinity-purified anti-HbF was immunohistochemically used to study F cell distribution in the following cancers: colorectal adenocarcinoma, urinary bladder transitional cell carcinoma, brain tumours, lung carcinoma, breast adenocarcinoma, leukaemia, Burkitt's lymphoma and endometrial carcinoma. RESULTS: In colorectal adenocarcinoma, HbF-containing red blood cells (FRBC) were present within thin-walled vessels or were disposed in dense clusters within the tumour. Some of these cells were nucleated or binucleated HbF-erythroblasts or HbF-normoblasts (FNBS). In two cases, high levels of mitoses within HbF-erythroblasts were observed. In half of the cases with transitional cell carcinoma of the urinary bladder, regional intratumoral blood vessels were found to contain 5-50% FRBC. In the other tumours examined, F cells were not observed. FRBCs, however, were occasionally observed in the regional lymph nodes of some of these cancers. CONCLUSIONS: The evaluation of HbF as a potential plasma marker is suggested by the high concentration of FRBCs in colorectal tumours. The apparent development of FRBCs in colorectal tumour tissues is an interesting observation, as these cells were previously thought to develop in medullary or lymphoid tissues. It is thus suggested that the colonic microenvironment may stimulate extramedullary fetal-type haematopoiesis.

Blood cells with fetal haemoglobin (F-cells) detected by immunohistochemistry as indicators of solid tumours.

AIMS: Fetal hemoglobin (HbF) is an established serological indicator of cancer. However, its distribution in tumour tissues is rarely investigated. Therefore, HbF was studied immunohistologically in different cancers characterised by high blood HbF concentrations. METHODS: Anti-HbF was immunoaffinity purified and used to study HbF immunohistochemically in the following cancers: germ cell tumour (GCT), trophoblastic disease (TD), lymphoma, myelodysplastic syndrome (MDS), multiple myeloma (MM), and ovarian adenocarcinoma (OA). RESULTS: In GCT a distinction was made between tumours substantially without HbF positive red blood cells (F-RBC) and those with F-RBC. Those without F-RBC were non-metastatic mature teratomas and dermoid cysts. Those containing F-RBC were mainly embryonal carcinomas and metastatic teratomas. HbF positive myeloid cells (F-MLC), HbF positive normoblasts (F-NBS), and F-RBC were common in the bone marrow and in the lymphoid tissues of lymphoma, MDS, and MM. In TD, normal and nucleated F-RBC were seen in the trophoblastic villi in one case with incomplete molar pregnancy (ICM) but not in other cases of ICM and complete molar pregnancy. However, F-RBC and F-MLC were seen in the decidua of both types of TD. Generally, F-cells were observed either within blood vessels or concentrated in certain areas of the neoplastic tissue. CONCLUSIONS: HbF was evaluated as an inducible marker within different tumour tissue blood cells. The dual distribution of these cells-circulating in the blood or concentrated in areas of the neoplastic tissues-might reflect the two independent serological indicators of HbF: one in whole blood and the other in plasma of patients with cancer.

[Multiresistant Escherichia coli from elderly patients].

We examined all ceftriaxone-resistant Escherichia coli isolates obtained from clinical samples during 16 months (1 Dec. '97-31 Mar. '99). A total of 97 resistant isolates from 36 patients were obtained, mostly from urine specimens. Of these patients, 35/36 were over 75 years old, most lived in nursing homes, were dependent on nursing in their daily lives, and were incontinent and/or had indwelling catheters. All 97 isolates had similar susceptibility profiles: resistant to ciprofloxacin, gentamicin, ampicillin, amoxycillin/clavulanate, tricarcillin/clavulanate, aztreonam, and cefuroxime; decreased susceptibility to ceftazidime and cefepime; and susceptible to imipenem and meropenem. Double-disc tests indicated that all strains produced extended spectrum beta-lactamase(s). All the isolates belonged to 1 of 3 E. coli serotypes: 79 were 0153:H31, 13 were 0142:H10, and 5 were 0102:H6.

Enterotoxigenic Escherichia coli (ETEC) in hospitalised Arab infants from Judea area--west bank, Israel.

Enterotoxigenic Escherichia coli and other related enterotoxigenic species were isolated from 176 (44%) of 399 infants hospitalised in 'Caritas Baby Hospital' in Bethlehem, during April-December 1993. Ninety four of the patients infected by ETEC, were clinically evaluated. Most of them suffered from diarrhoea, quite often with fever and vomiting. Dehydration occurred in 58.3% of the patients and failure to thrive (FTT) in 28.5% of them. Severe illness resulted in marasmus in five patients and in the death of two others. Most of the ETEC strains (84%) were of ST toxin type. Correlation was found between the degree of toxigenity and the severity of the gastroenteritis. The most prevalent ETEC "O' serogroups were 0-6, 0-20, 0-8, 0-86, 0-126, 0-128 and 0167. Colonization Factors Antigens (CFAs) were identified in 36% of the isolates, CFAI was characteristic of group 0-126 and 0-128. In the principal O-groups there were high percentages of sensitivity to the antibiotics ceftriaxone, nalidixic-acid, gentamicin and norfloxacin, with resistance to anoxycillin, tetracycline and cotrimoxazole.

Effect of managed care on cardiovascular specialists: involvement, attitudes and practice adaptations.

OBJECTIVES: This study was undertaken to determine the extent to which cardiovascular specialists are involved with and affected by managed care and to ascertain their attitudes toward it. This survey also served as the follow-up to an initial study on the subject performed by the American College of Cardiology in 1993. BACKGROUND: The initial 1993 study was performed to address the lack of any comprehensive examination of the impact of managed care on cardiovascular specialists. In 1995, to reexplore this question and follow up the 1993 findings, the College conducted a survey of its membership in the following areas: 1) physician relationship with managed care plans; 2) number of managed care contracts; 3) breakdown of revenue by payment source; 4) changes in practice in response to managed care; and 5) physician attitudes toward managed care. To the extent feasible, the 1995 questionnaire paralleled the 1993 instrument to facilitate comparisons. METHODS: A questionnaire was mailed to 5,147 practicing College members in the United States, who were categorized by specialty as pediatric cardiologists, adult cardiologists or cardiovascular surgeons. Mailings were sent to 1) all pediatric cardiologists and cardiovascular surgeons; 2) randomly selected adult cardiologists practicing in 10 states with high managed care penetration; and 3) randomly selected adult cardiologists in the nine U.S. census areas who were not practicing in the 10 states with high managed care penetration. RESULTS: Usable surveys were returned by 1,236 respondents, for an overall response rate of 24%. Involvement with at least one type of managed care organization was reported by 89% of respondents, up from 76% in 1993. Although managed care relationships had increased across physician age, region, practice and specialty, respondents indicated that, on average, well below 50% of their practice revenues stem from managed care contracts. To adapt to the managed care environment, strategic practice changes, such as joining a cardiovascular network, implementing continuous quality improvement systems and adopting clinical pathways, were being instituted by most respondent practices of nine or more physicians. Smaller groups were less active. Most respondents involved with managed care disliked its effects, particularly in clinical matters. Their attitudes toward the assumption of risk, managed fee-for-service arrangements and a private versus single-payer system show that there is no uniformity of opinion regarding the best means to contain costs and promote efficiency. CONCLUSIONS: Managed care has become an established part of cardiovascular specialist practice in the United States. Although this trend is viewed with some disfavor, most respondents are making practice changes to adapt to this new environment.

Mood and the use of scripts: does a happy mood really lead to mindlessness?

The authors tested whether happy moods increase, and sad moods decrease, reliance on general knowledge structures. Participants in happy, neutral, or sad moods listened to a "going-out-for-dinner" story. Happy participants made more intrusion errors in recognition than did sad participants, with neutral mood participants falling in between (Experiments 1 and 2). Happy participants outperformed sad ones when they performed a secondary task while listening to the story (Experiment 2), but only when the amount of script-inconsistent information was small (Experiment 3). This pattern of findings indicates higher reliance on general knowledge structures under happy rather than sad moods. It is incompatible with the assumption that happy moods decrease either cognitive capacity or processing motivation in general, which would predict impaired secondary-task performance.

Whither the PRO? Analysis of the effectiveness of three Medicare peer review organizations in a Florida hospital.

The objective of this retrospective study was to evaluate the effectiveness of a peer review organization (PRO) on patient mortality rate in a not-for-profit, 988-bed community hospital in Florida. The number of deaths per hospital discharge (mortality) was compared prior to the Professional Foundation for Health Care (PFHC) holding the contract as the Medicare PRO (1983), during two years in which the PRO was fully active (1990 and 1991), during the year limited PRO activities were conducted (1992), and when PRO activities were again fully expanded (1993). All Medicare hospital discharges, including deaths, were included from January through May during 1983, 1990 through 1993. There was no intervention. Patient mortality as a determinant of PRO effectiveness was evaluated prior to the PRO, during a portion of the years the PFHC held the contract as the Medicare PRO, and an identical time period one year later with limited PRO review and again the following year when full reviews returned. The number of deaths did not change significantly. Mandated peer reviews of care to inpatient hospital Medicare beneficiaries did not significantly improve health care as measured by mortality.

Epidemiological aspects of enterotoxigenic Escherichia coli diarrhoea in infants in the Jerusalem area.

BACKGROUND: As most of the clinical laboratories in Israel do not use toxigenicity testing as a routine procedure in cases of Escherichia coli gastroenteritis, current information regarding clinical and epidemiological aspects of infection by enterotoxigenic E. coli (ETEC) is lacking. This survey aimed at retrieving that information by conducting routine enterotoxigenicity tests in a clinical laboratory for patients suspected of E. coli gastroenteritis. METHODS: The survey population included 415 children < or = 2.5 years old with gastroenteritis, during the second half of 1992. Fresh first stool cultures were checked daily for toxigenicity by ELISA. Thereafter the serotypes, and the colonization factor antigens (CFAs) were evaluated for the ETEC strains. RESULTS: in 86 of the 415 children (20.7%) we found ETEC. Half these strains would have not been reported as pathogenic without this routine toxigenicity test. CFA were defined in 48 (55.8%) of the ETEC strains. The most common serogroups were O-153, O-6, O-126, and O-128.