MLL targets SET domain methyltransferase activity to Hox gene promoters

MLL, the human homolog of Drosophila trithorax, maintains Hox gene expression in mammalian embryos and is rearranged in human leukemias resulting in Hox gene deregulation. How MLL or MLL fusion proteins regulate gene expression remains obscure. We show that MLL regulates target Hox gene expression through direct binding to promoter sequences. We further show that the MLL SET domain is a histone H3 lysine 4-specific methyltransferase whose activity is stimulated with acetylated H3 peptides. This methylase activity is associated with Hox gene activation and H3 (Lys4) methylation at cis-regulatory sequences in vivo. A leukemogenic MLL fusion protein that activates Hox expression had no effect on histone methylation, suggesting a distinct mechanism for gene regulation by MLL and MLL fusion proteins.

Dendritic cell density and activation status in human breast cancer -- CD1a, CMRF-44, CMRF-56 and CD-83 expression

Low CD1a-positive putative dendritic cell numbers in human breast cancer has recently been described and may explain the apparent 'poor immunogenicity' previously reported in breast cancer. Little attention has been given to dendritic cell activation within the tumour microenvironment, which is another reason why the in-situ immune response may be severely deficient. We have therefore examined CD1a expression as a marker for dendritic cells, together with CMRF-44 and -56 as markers of dendritic cell activation status, in 40 human breast cancers. The results demonstrate few or no CD1a-positive putative dendritic cells and minimal or no expression of the dendritic cell activation markers. Both dendritic cell number and dendritic cell activation appear substantially deficient in human breast cancers, regardless of tumour histological grade.

Providing information to help Medicare beneficiaries choose a health plan

Many Medicare beneficiaries have limited knowledge of the Medicare program and related health insurance options. This is due in part to the complexity of the Medicare program and supplemental health insurance market. A recent congressional mandate through the Balanced Budget Act of 1997 called for broad dissemination of information to educate beneficiaries about their health plan options and to encourage informed health plan decision-making. In response, the Health Care Financing Administration (HCFA) launched the National Medicare Education Program (NMEP) to support the educational objectives of the BBA. This paper provides an overview of the components of the NMEP information campaign. We also review lessons learned from our experience in designing and testing a prototype consumer handbook that explains the different health plan options to Medicare beneficiaries. Through our discussion of the handbook, we highlight several ways to communicate information effectively about a complex publicly funded program to an older adult population.

A novel keratin 5 mutation (K5V186L) in a family with EBS-K: a conservative substitution can lead to development of different disease phenotypes

Epidermolysis bullosa simplex is a hereditary skin blistering disorder caused by mutations in the KRT5 or KRT14 genes. More than 50 different mutations have been described so far. These, and reports of other keratin gene mutations, have highlighted the existence of mutation "hotspots" in keratin proteins at which sequence changes are most likely to be detrimental to protein function. Pathogenic mutations that occur outside these hotspots are usually associated with less severe disease phenotypes. We describe a novel K5 mutation (V186L) that produces a conservative amino acid change (valine to leucine) at position 18 of the 1A helix. The phenotype of this case is unexpectedly severe for the location of the mutation, which lies outside the consensus helix initiation motif mutation hotspot, and other mutations at this position have been associated in Weber--Cockayne (mild) epidermolysis bullosa simplex only. The mutation was confirmed by mismatch-allele-specific polymerase chain reaction and the entire KRT5 coding region was sequenced, but no other changes were identified. De novo K5/K14 (mutant and wild-type) filament assembly in cultured cells was studied to determine the effect of this mutation on filament polymerization and stability. A computer model of the 1A region of the K5/K14 coiled-coil was generated to visualize the structural impact of this mutation and to compare it with an analogous mutation causing mild disease. The results show a high level of concordance between genetic, cell culture and molecular modeling data, suggesting that even a conservative substitution can cause severe dysfunction in a structural protein, depending on the size and structure of the amino acid involved.

A two year global evaluation of the susceptibility of Candida species to fluconazole by disk diffusion

The in-vitro activity of fluconazole against 46,831 yeast isolates collected over a two-year period from 57 laboratories in 33 countries worldwide was assessed using a disc diffusion method. Candida albicans was the organism isolated most frequently, accounting for 68.6% of the total number of isolates. C. glabrata, C. tropicalis, C parapsilosis and C. krusei and Cryptococcus neoformans represented 9.9, 4.7, 4.3, 1.9, and 1.4% of isolates respectively during the 2 year period and rates varied markedly between countries. In 1999 data blood isolates represented 4.9% of all isolates and intensive care unit isolates represented 9.9%. In both the 1998 and 1999 data, 99% of C. albicans were fully susceptible (S) to fluconazole, and 95.6% of all species of yeasts tested were S or susceptible-dose dependent (S-DD) to fluconazole. No emerging trends of resistance were noted with any of the Candida spp. tested as 96% of all isolates retained susceptibility (S or S-DD) to this agent.

X-Ray anomalous scattering study of a charge-ordered state in NaV2O5

Charge ordering of V4+ and V5+ in NaV2O5 has been studied by an x-ray diffraction technique using anomalous scattering near a vanadium K-absorption edge to critically enhance a contrast between the two ions. A dramatic energy dependence of the superlattice intensities is observed below T(C) = 35 K. The charge ordering pattern is the fully charged zigzag-type ladder with the unit cell 2ax2bx4c, but not the chain-type originally proposed for the spin-Peierls state. Charge disproportionation suggested in our model as the average valence V(4.5+/-delta(c)/2) is observed below T(C), showing continuous variation of delta(c) as a function of temperature.

Spin dynamics and orbital state in LaTiO3

A neutron scattering study of the Mott-Hubbard insulator LaTiO3 ( T(N) = 132 K) reveals a spin wave spectrum that is well described by a nearest-neighbor superexchange constant J = 15.5 meV and a small Dzyaloshinskii-Moriya interaction ( D = 1.1 meV). The nearly isotropic spin wave spectrum is surprising in view of the absence of a static Jahn-Teller distortion that could quench the orbital angular momentum, and it may indicate strong orbital fluctuations. A resonant x-ray scattering study has uncovered no evidence of orbital order in LaTiO3.

A global evaluation of the susceptibility of Candida species to fluconazole by disk diffusion. Global Antifungal Surveillance Group

An improved fluconazole 25-mg disk diffusion method was used to test the susceptibility of 20,900 consecutively isolated clinical strains of Candida species from 40 hospital laboratories in 26 countries. The procedure is similar to the National Committee for Clinical Laboratory Standards (NCCLS) M2-A6 method for testing bacteria, except Mueller-Hinton agar is supplemented with 2% glucose and 0.5 mcg/mL methylene blue. Plates were incubated at 35 degrees C and read after 18 to 24h. Tentative zone interpretive criteria were based on the correlation by regression analysis with the NCCLS M27-A Reference Method for Broth Dilution Antifungal Susceptibility Testing of Yeasts: > =19mm Susceptible, < = 12mm Resistant, and 13-18 mm Susceptible-Dose Dependent. Of 14,368 isolates of Candida albicans, 2,073 C. glabrata, 869 C. tropicalis, 752 C. parapsilosis, and 351 C. krusei, 99%, 67%, 90%, 94%, and 26%, respectively, were susceptible in vitro to fluconazole. All study sites used the BIOMIC System to electronically read zones on plates, interpret, record test results and verify quality control data. This is the largest study to date that evaluated a broad range of sequentially collected yeasts from various infections and different types of hospitals. The modified disk testing procedure is facile and economical to perform and offers a reproducible and accurate means to assess the in vitro susceptibility of Candida species to fluconazole.

When a cane was the necessary complement of a physician

Although Dr John Radcliffe's gold-headed cane, presented to the Royal College of Physicians in 1825, became well-known following the publication two years later of Dr William Macmichael's book, The gold-headed cane, little consideration has previously been given either to medical canes, or to the custom of cane-carrying by doctors in the 18th century. This article makes a brief assessment of medical canes within the social and historical framework of the period, and views Macmichael's book in its literary context, with mention of other relevant examples of books in this genre.

Organ and tissue donation: are minorities willing to donate?

The Task Force on Organ Transplantation (DHHS,1986) addressed the issue of increasing organ donation. The Report of the Task Force recommended that "educational efforts aimed at increasing organ donation among minority populations be developed and implemented, so that the donor population will more closely reflect the ethnicity of potential transplant recipients, in order to gain the advantage of improved donor and recipient immunologic matching (DHHS,1986). Donor rates for minorities has increased as follows: 16% in 1988 to 23% in 1995 among cadaveric donors and 24% in 1988 to 28% in 1995 among living donors. The improvement in donor rates among minorities may positively affect the transplantation success rate experienced by organ recipients of the same race. Strategies must be implemented that will increase the effectiveness and frequency of communication between minority patients and the medical community. An increase in the effectiveness of communication between potential minority donor families and the health care community will contribute to the process of Consciousness Raising as discussed by Prochasksa. The result of increased awareness of the organ donation and transplantation process may have a favorable impact on organ donation. The media has, through public service announcements, paid advertising and entertainment programming, attempted to promote discussion of organ donation in the community and within families. Johnson et al. discussed Mexican-American and Anglo-American Attitudes Toward Organ Donation. The primary impediment contributing to the disparity of consent rates between Mexican-American and Anglo-American population occurs with regard to the donation of organs of relatives. Johnson stated that this impediment to organ donation can be effectively addressed by promoting family discussion. Communication within families will inform surviving next of kin of the desire of the deceased to be an organ donor and hence improve the likelihood of the donor family consenting to organ donation (Johnson et al., 1988). The promotion of communication within families must continue to be a goal of the transplant community regardless of race/ethnicity. Despite the efforts of the government, the transplant community, the media and the corporate sector to address the critical shortage of donors in the United States, the reality is that no community has the supply of donor organs suitable to meet the need.

Fluconazole orally dispersible tablets for the treatment of patients with oropharyngeal candidiasis

The efficacy and tolerability of fluconazole orally dispersible tablets (ODT) in the treatment of oropharyngeal candidiasis was evaluated in this multicentre non-comparative study. A total of 89 adults with signs and symptoms of oropharyngeal candidiasis were enrolled; 70 of whom completed therapy with fluconazole ODT 100 mg once daily for 7 - 14 days. Acquired immunodeficiency syndrome (AIDS)/ AIDS-related complex was an underlying illness in 69% of patients (61). An antimicrobial and corticosteroid therapy was given in 52% (46) and 20% (18) of patients, respectively. Of the 60 patients who had baseline signs and symptoms of infection and a culture positive for Candida albicans, 90% (54) were cured or had improved at the end of therapy, and the fungal pathogen was eradicated in 19/57 (33%) patients. At the 4-week posttreatment follow-up, signs and symptoms of oropharyngeal candidiasis were absent in 73% (27/37) patients. The adverse events and laboratory abnormalities recorded during the study period were attributable to underlying illnesses rather than to fluconazole therapy. These results indicate that this novel dosage form of fluconazole is effective and well tolerated in the treatment of oropharyngeal candidiasis.

Ganciclovir implant exchange. Timing, surgical procedure, and complications

BACKGROUND

The ganciclovir implant is effective for the treatment of cytomegalovirus (CMV) retinitis. The device eventually runs out of drug, however, and must be replaced. We report our experience with exchanging ganciclovir implants during the course of a randomized clinical trial.

METHODS

During our study, patients with newly diagnosed peripheral CMV retinitis were treated with a ganciclovir implant. The implant was scheduled for exchange at 32 weeks. It was exchanged earlier if progression of CMV retinitis occurred. Patient examinations and standard fundus photography were performed at 2-week intervals after the exchange procedure.

RESULTS

Twenty-six exchange procedures were performed. Twenty-two eyes in 15 patients received a second implant and 4 eyes in 4 patients later received a third implant. Cytomegalovirus retinitis was rendered or maintained inactive in 22 of 23 cases with more than 1 month of follow-up after the second or third implants. Complications after the second implant procedure included transient vitreous hemorrhage in 5 eyes, postoperative inflammation in 1 eye, and retinal detachment in 1 eye. Median visual acuity returned to 20/25 by 28 days and to 20/20 by 42 days. Complications after the third implant procedure included dense vitreous hemorrhage in 3 of 4 eyes. Median survival time after a second implant procedure was 89 days.

CONCLUSIONS

The initial ganciclovir implant exchange procedure is well tolerated with continued long-term control of CMV retinitis. Multiple reentries through the same wound may be associated with an increased risk for vitreous hemorrhage.

The college suspended

A satirical account of the raising of the Royal College of Physicians and its suspension from a balloon for three months is included among Baron Munchausen's later surprising adventures. Portrayals by artists of this flight of fancy involving the College are not widely known. Three pictorial representations of the raising of the College are shown and some of the historical context of the tall tale is given.